xref: /linux/drivers/target/target_core_transport.c (revision 97f0b13452198290799fd6780f05fbaa74f927d3)
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 <asm/unaligned.h>
38 #include <net/sock.h>
39 #include <net/tcp.h>
40 #include <scsi/scsi_proto.h>
41 
42 #include <target/target_core_base.h>
43 #include <target/target_core_backend.h>
44 #include <target/target_core_fabric.h>
45 #include <target/target_core_configfs.h>
46 
47 #include "target_core_internal.h"
48 #include "target_core_alua.h"
49 #include "target_core_pr.h"
50 #include "target_core_ua.h"
51 
52 #define CREATE_TRACE_POINTS
53 #include <trace/events/target.h>
54 
55 static struct workqueue_struct *target_completion_wq;
56 static struct kmem_cache *se_sess_cache;
57 struct kmem_cache *se_ua_cache;
58 struct kmem_cache *t10_pr_reg_cache;
59 struct kmem_cache *t10_alua_lu_gp_cache;
60 struct kmem_cache *t10_alua_lu_gp_mem_cache;
61 struct kmem_cache *t10_alua_tg_pt_gp_cache;
62 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
63 struct kmem_cache *t10_alua_lba_map_cache;
64 struct kmem_cache *t10_alua_lba_map_mem_cache;
65 
66 static void transport_complete_task_attr(struct se_cmd *cmd);
67 static void transport_handle_queue_full(struct se_cmd *cmd,
68 		struct se_device *dev);
69 static int transport_put_cmd(struct se_cmd *cmd);
70 static void target_complete_ok_work(struct work_struct *work);
71 
72 int init_se_kmem_caches(void)
73 {
74 	se_sess_cache = kmem_cache_create("se_sess_cache",
75 			sizeof(struct se_session), __alignof__(struct se_session),
76 			0, NULL);
77 	if (!se_sess_cache) {
78 		pr_err("kmem_cache_create() for struct se_session"
79 				" failed\n");
80 		goto out;
81 	}
82 	se_ua_cache = kmem_cache_create("se_ua_cache",
83 			sizeof(struct se_ua), __alignof__(struct se_ua),
84 			0, NULL);
85 	if (!se_ua_cache) {
86 		pr_err("kmem_cache_create() for struct se_ua failed\n");
87 		goto out_free_sess_cache;
88 	}
89 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
90 			sizeof(struct t10_pr_registration),
91 			__alignof__(struct t10_pr_registration), 0, NULL);
92 	if (!t10_pr_reg_cache) {
93 		pr_err("kmem_cache_create() for struct t10_pr_registration"
94 				" failed\n");
95 		goto out_free_ua_cache;
96 	}
97 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
98 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
99 			0, NULL);
100 	if (!t10_alua_lu_gp_cache) {
101 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
102 				" failed\n");
103 		goto out_free_pr_reg_cache;
104 	}
105 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
106 			sizeof(struct t10_alua_lu_gp_member),
107 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
108 	if (!t10_alua_lu_gp_mem_cache) {
109 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
110 				"cache failed\n");
111 		goto out_free_lu_gp_cache;
112 	}
113 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
114 			sizeof(struct t10_alua_tg_pt_gp),
115 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
116 	if (!t10_alua_tg_pt_gp_cache) {
117 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
118 				"cache failed\n");
119 		goto out_free_lu_gp_mem_cache;
120 	}
121 	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
122 			"t10_alua_tg_pt_gp_mem_cache",
123 			sizeof(struct t10_alua_tg_pt_gp_member),
124 			__alignof__(struct t10_alua_tg_pt_gp_member),
125 			0, NULL);
126 	if (!t10_alua_tg_pt_gp_mem_cache) {
127 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
128 				"mem_t failed\n");
129 		goto out_free_tg_pt_gp_cache;
130 	}
131 	t10_alua_lba_map_cache = kmem_cache_create(
132 			"t10_alua_lba_map_cache",
133 			sizeof(struct t10_alua_lba_map),
134 			__alignof__(struct t10_alua_lba_map), 0, NULL);
135 	if (!t10_alua_lba_map_cache) {
136 		pr_err("kmem_cache_create() for t10_alua_lba_map_"
137 				"cache failed\n");
138 		goto out_free_tg_pt_gp_mem_cache;
139 	}
140 	t10_alua_lba_map_mem_cache = kmem_cache_create(
141 			"t10_alua_lba_map_mem_cache",
142 			sizeof(struct t10_alua_lba_map_member),
143 			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
144 	if (!t10_alua_lba_map_mem_cache) {
145 		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
146 				"cache failed\n");
147 		goto out_free_lba_map_cache;
148 	}
149 
150 	target_completion_wq = alloc_workqueue("target_completion",
151 					       WQ_MEM_RECLAIM, 0);
152 	if (!target_completion_wq)
153 		goto out_free_lba_map_mem_cache;
154 
155 	return 0;
156 
157 out_free_lba_map_mem_cache:
158 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
159 out_free_lba_map_cache:
160 	kmem_cache_destroy(t10_alua_lba_map_cache);
161 out_free_tg_pt_gp_mem_cache:
162 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
163 out_free_tg_pt_gp_cache:
164 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
165 out_free_lu_gp_mem_cache:
166 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
167 out_free_lu_gp_cache:
168 	kmem_cache_destroy(t10_alua_lu_gp_cache);
169 out_free_pr_reg_cache:
170 	kmem_cache_destroy(t10_pr_reg_cache);
171 out_free_ua_cache:
172 	kmem_cache_destroy(se_ua_cache);
173 out_free_sess_cache:
174 	kmem_cache_destroy(se_sess_cache);
175 out:
176 	return -ENOMEM;
177 }
178 
179 void release_se_kmem_caches(void)
180 {
181 	destroy_workqueue(target_completion_wq);
182 	kmem_cache_destroy(se_sess_cache);
183 	kmem_cache_destroy(se_ua_cache);
184 	kmem_cache_destroy(t10_pr_reg_cache);
185 	kmem_cache_destroy(t10_alua_lu_gp_cache);
186 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
187 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
188 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
189 	kmem_cache_destroy(t10_alua_lba_map_cache);
190 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
191 }
192 
193 /* This code ensures unique mib indexes are handed out. */
194 static DEFINE_SPINLOCK(scsi_mib_index_lock);
195 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
196 
197 /*
198  * Allocate a new row index for the entry type specified
199  */
200 u32 scsi_get_new_index(scsi_index_t type)
201 {
202 	u32 new_index;
203 
204 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
205 
206 	spin_lock(&scsi_mib_index_lock);
207 	new_index = ++scsi_mib_index[type];
208 	spin_unlock(&scsi_mib_index_lock);
209 
210 	return new_index;
211 }
212 
213 void transport_subsystem_check_init(void)
214 {
215 	int ret;
216 	static int sub_api_initialized;
217 
218 	if (sub_api_initialized)
219 		return;
220 
221 	ret = request_module("target_core_iblock");
222 	if (ret != 0)
223 		pr_err("Unable to load target_core_iblock\n");
224 
225 	ret = request_module("target_core_file");
226 	if (ret != 0)
227 		pr_err("Unable to load target_core_file\n");
228 
229 	ret = request_module("target_core_pscsi");
230 	if (ret != 0)
231 		pr_err("Unable to load target_core_pscsi\n");
232 
233 	ret = request_module("target_core_user");
234 	if (ret != 0)
235 		pr_err("Unable to load target_core_user\n");
236 
237 	sub_api_initialized = 1;
238 }
239 
240 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
241 {
242 	struct se_session *se_sess;
243 
244 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
245 	if (!se_sess) {
246 		pr_err("Unable to allocate struct se_session from"
247 				" se_sess_cache\n");
248 		return ERR_PTR(-ENOMEM);
249 	}
250 	INIT_LIST_HEAD(&se_sess->sess_list);
251 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
252 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
253 	INIT_LIST_HEAD(&se_sess->sess_wait_list);
254 	spin_lock_init(&se_sess->sess_cmd_lock);
255 	kref_init(&se_sess->sess_kref);
256 	se_sess->sup_prot_ops = sup_prot_ops;
257 
258 	return se_sess;
259 }
260 EXPORT_SYMBOL(transport_init_session);
261 
262 int transport_alloc_session_tags(struct se_session *se_sess,
263 			         unsigned int tag_num, unsigned int tag_size)
264 {
265 	int rc;
266 
267 	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
268 					GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
269 	if (!se_sess->sess_cmd_map) {
270 		se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
271 		if (!se_sess->sess_cmd_map) {
272 			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
273 			return -ENOMEM;
274 		}
275 	}
276 
277 	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
278 	if (rc < 0) {
279 		pr_err("Unable to init se_sess->sess_tag_pool,"
280 			" tag_num: %u\n", tag_num);
281 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
282 			vfree(se_sess->sess_cmd_map);
283 		else
284 			kfree(se_sess->sess_cmd_map);
285 		se_sess->sess_cmd_map = NULL;
286 		return -ENOMEM;
287 	}
288 
289 	return 0;
290 }
291 EXPORT_SYMBOL(transport_alloc_session_tags);
292 
293 struct se_session *transport_init_session_tags(unsigned int tag_num,
294 					       unsigned int tag_size,
295 					       enum target_prot_op sup_prot_ops)
296 {
297 	struct se_session *se_sess;
298 	int rc;
299 
300 	se_sess = transport_init_session(sup_prot_ops);
301 	if (IS_ERR(se_sess))
302 		return se_sess;
303 
304 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
305 	if (rc < 0) {
306 		transport_free_session(se_sess);
307 		return ERR_PTR(-ENOMEM);
308 	}
309 
310 	return se_sess;
311 }
312 EXPORT_SYMBOL(transport_init_session_tags);
313 
314 /*
315  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
316  */
317 void __transport_register_session(
318 	struct se_portal_group *se_tpg,
319 	struct se_node_acl *se_nacl,
320 	struct se_session *se_sess,
321 	void *fabric_sess_ptr)
322 {
323 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
324 	unsigned char buf[PR_REG_ISID_LEN];
325 
326 	se_sess->se_tpg = se_tpg;
327 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
328 	/*
329 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
330 	 *
331 	 * Only set for struct se_session's that will actually be moving I/O.
332 	 * eg: *NOT* discovery sessions.
333 	 */
334 	if (se_nacl) {
335 		/*
336 		 *
337 		 * Determine if fabric allows for T10-PI feature bits exposed to
338 		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
339 		 *
340 		 * If so, then always save prot_type on a per se_node_acl node
341 		 * basis and re-instate the previous sess_prot_type to avoid
342 		 * disabling PI from below any previously initiator side
343 		 * registered LUNs.
344 		 */
345 		if (se_nacl->saved_prot_type)
346 			se_sess->sess_prot_type = se_nacl->saved_prot_type;
347 		else if (tfo->tpg_check_prot_fabric_only)
348 			se_sess->sess_prot_type = se_nacl->saved_prot_type =
349 					tfo->tpg_check_prot_fabric_only(se_tpg);
350 		/*
351 		 * If the fabric module supports an ISID based TransportID,
352 		 * save this value in binary from the fabric I_T Nexus now.
353 		 */
354 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
355 			memset(&buf[0], 0, PR_REG_ISID_LEN);
356 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
357 					&buf[0], PR_REG_ISID_LEN);
358 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
359 		}
360 		kref_get(&se_nacl->acl_kref);
361 
362 		spin_lock_irq(&se_nacl->nacl_sess_lock);
363 		/*
364 		 * The se_nacl->nacl_sess pointer will be set to the
365 		 * last active I_T Nexus for each struct se_node_acl.
366 		 */
367 		se_nacl->nacl_sess = se_sess;
368 
369 		list_add_tail(&se_sess->sess_acl_list,
370 			      &se_nacl->acl_sess_list);
371 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
372 	}
373 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
374 
375 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
376 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
377 }
378 EXPORT_SYMBOL(__transport_register_session);
379 
380 void transport_register_session(
381 	struct se_portal_group *se_tpg,
382 	struct se_node_acl *se_nacl,
383 	struct se_session *se_sess,
384 	void *fabric_sess_ptr)
385 {
386 	unsigned long flags;
387 
388 	spin_lock_irqsave(&se_tpg->session_lock, flags);
389 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
390 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
391 }
392 EXPORT_SYMBOL(transport_register_session);
393 
394 static void target_release_session(struct kref *kref)
395 {
396 	struct se_session *se_sess = container_of(kref,
397 			struct se_session, sess_kref);
398 	struct se_portal_group *se_tpg = se_sess->se_tpg;
399 
400 	se_tpg->se_tpg_tfo->close_session(se_sess);
401 }
402 
403 void target_get_session(struct se_session *se_sess)
404 {
405 	kref_get(&se_sess->sess_kref);
406 }
407 EXPORT_SYMBOL(target_get_session);
408 
409 void target_put_session(struct se_session *se_sess)
410 {
411 	struct se_portal_group *tpg = se_sess->se_tpg;
412 
413 	if (tpg->se_tpg_tfo->put_session != NULL) {
414 		tpg->se_tpg_tfo->put_session(se_sess);
415 		return;
416 	}
417 	kref_put(&se_sess->sess_kref, target_release_session);
418 }
419 EXPORT_SYMBOL(target_put_session);
420 
421 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
422 {
423 	struct se_session *se_sess;
424 	ssize_t len = 0;
425 
426 	spin_lock_bh(&se_tpg->session_lock);
427 	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
428 		if (!se_sess->se_node_acl)
429 			continue;
430 		if (!se_sess->se_node_acl->dynamic_node_acl)
431 			continue;
432 		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
433 			break;
434 
435 		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
436 				se_sess->se_node_acl->initiatorname);
437 		len += 1; /* Include NULL terminator */
438 	}
439 	spin_unlock_bh(&se_tpg->session_lock);
440 
441 	return len;
442 }
443 EXPORT_SYMBOL(target_show_dynamic_sessions);
444 
445 static void target_complete_nacl(struct kref *kref)
446 {
447 	struct se_node_acl *nacl = container_of(kref,
448 				struct se_node_acl, acl_kref);
449 
450 	complete(&nacl->acl_free_comp);
451 }
452 
453 void target_put_nacl(struct se_node_acl *nacl)
454 {
455 	kref_put(&nacl->acl_kref, target_complete_nacl);
456 }
457 
458 void transport_deregister_session_configfs(struct se_session *se_sess)
459 {
460 	struct se_node_acl *se_nacl;
461 	unsigned long flags;
462 	/*
463 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
464 	 */
465 	se_nacl = se_sess->se_node_acl;
466 	if (se_nacl) {
467 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
468 		if (se_nacl->acl_stop == 0)
469 			list_del(&se_sess->sess_acl_list);
470 		/*
471 		 * If the session list is empty, then clear the pointer.
472 		 * Otherwise, set the struct se_session pointer from the tail
473 		 * element of the per struct se_node_acl active session list.
474 		 */
475 		if (list_empty(&se_nacl->acl_sess_list))
476 			se_nacl->nacl_sess = NULL;
477 		else {
478 			se_nacl->nacl_sess = container_of(
479 					se_nacl->acl_sess_list.prev,
480 					struct se_session, sess_acl_list);
481 		}
482 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
483 	}
484 }
485 EXPORT_SYMBOL(transport_deregister_session_configfs);
486 
487 void transport_free_session(struct se_session *se_sess)
488 {
489 	if (se_sess->sess_cmd_map) {
490 		percpu_ida_destroy(&se_sess->sess_tag_pool);
491 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
492 			vfree(se_sess->sess_cmd_map);
493 		else
494 			kfree(se_sess->sess_cmd_map);
495 	}
496 	kmem_cache_free(se_sess_cache, se_sess);
497 }
498 EXPORT_SYMBOL(transport_free_session);
499 
500 void transport_deregister_session(struct se_session *se_sess)
501 {
502 	struct se_portal_group *se_tpg = se_sess->se_tpg;
503 	const struct target_core_fabric_ops *se_tfo;
504 	struct se_node_acl *se_nacl;
505 	unsigned long flags;
506 	bool comp_nacl = true;
507 
508 	if (!se_tpg) {
509 		transport_free_session(se_sess);
510 		return;
511 	}
512 	se_tfo = se_tpg->se_tpg_tfo;
513 
514 	spin_lock_irqsave(&se_tpg->session_lock, flags);
515 	list_del(&se_sess->sess_list);
516 	se_sess->se_tpg = NULL;
517 	se_sess->fabric_sess_ptr = NULL;
518 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
519 
520 	/*
521 	 * Determine if we need to do extra work for this initiator node's
522 	 * struct se_node_acl if it had been previously dynamically generated.
523 	 */
524 	se_nacl = se_sess->se_node_acl;
525 
526 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
527 	if (se_nacl && se_nacl->dynamic_node_acl) {
528 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
529 			list_del(&se_nacl->acl_list);
530 			se_tpg->num_node_acls--;
531 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
532 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
533 			core_free_device_list_for_node(se_nacl, se_tpg);
534 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
535 
536 			comp_nacl = false;
537 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
538 		}
539 	}
540 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
541 
542 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
543 		se_tpg->se_tpg_tfo->get_fabric_name());
544 	/*
545 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
546 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
547 	 * removal context.
548 	 */
549 	if (se_nacl && comp_nacl)
550 		target_put_nacl(se_nacl);
551 
552 	transport_free_session(se_sess);
553 }
554 EXPORT_SYMBOL(transport_deregister_session);
555 
556 /*
557  * Called with cmd->t_state_lock held.
558  */
559 static void target_remove_from_state_list(struct se_cmd *cmd)
560 {
561 	struct se_device *dev = cmd->se_dev;
562 	unsigned long flags;
563 
564 	if (!dev)
565 		return;
566 
567 	if (cmd->transport_state & CMD_T_BUSY)
568 		return;
569 
570 	spin_lock_irqsave(&dev->execute_task_lock, flags);
571 	if (cmd->state_active) {
572 		list_del(&cmd->state_list);
573 		cmd->state_active = false;
574 	}
575 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
576 }
577 
578 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
579 				    bool write_pending)
580 {
581 	unsigned long flags;
582 
583 	spin_lock_irqsave(&cmd->t_state_lock, flags);
584 	if (write_pending)
585 		cmd->t_state = TRANSPORT_WRITE_PENDING;
586 
587 	if (remove_from_lists) {
588 		target_remove_from_state_list(cmd);
589 
590 		/*
591 		 * Clear struct se_cmd->se_lun before the handoff to FE.
592 		 */
593 		cmd->se_lun = NULL;
594 	}
595 
596 	/*
597 	 * Determine if frontend context caller is requesting the stopping of
598 	 * this command for frontend exceptions.
599 	 */
600 	if (cmd->transport_state & CMD_T_STOP) {
601 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
602 			__func__, __LINE__,
603 			cmd->se_tfo->get_task_tag(cmd));
604 
605 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
606 
607 		complete_all(&cmd->t_transport_stop_comp);
608 		return 1;
609 	}
610 
611 	cmd->transport_state &= ~CMD_T_ACTIVE;
612 	if (remove_from_lists) {
613 		/*
614 		 * Some fabric modules like tcm_loop can release
615 		 * their internally allocated I/O reference now and
616 		 * struct se_cmd now.
617 		 *
618 		 * Fabric modules are expected to return '1' here if the
619 		 * se_cmd being passed is released at this point,
620 		 * or zero if not being released.
621 		 */
622 		if (cmd->se_tfo->check_stop_free != NULL) {
623 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
624 			return cmd->se_tfo->check_stop_free(cmd);
625 		}
626 	}
627 
628 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
629 	return 0;
630 }
631 
632 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
633 {
634 	return transport_cmd_check_stop(cmd, true, false);
635 }
636 
637 static void transport_lun_remove_cmd(struct se_cmd *cmd)
638 {
639 	struct se_lun *lun = cmd->se_lun;
640 
641 	if (!lun)
642 		return;
643 
644 	if (cmpxchg(&cmd->lun_ref_active, true, false))
645 		percpu_ref_put(&lun->lun_ref);
646 }
647 
648 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
649 {
650 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
651 		transport_lun_remove_cmd(cmd);
652 	/*
653 	 * Allow the fabric driver to unmap any resources before
654 	 * releasing the descriptor via TFO->release_cmd()
655 	 */
656 	if (remove)
657 		cmd->se_tfo->aborted_task(cmd);
658 
659 	if (transport_cmd_check_stop_to_fabric(cmd))
660 		return;
661 	if (remove)
662 		transport_put_cmd(cmd);
663 }
664 
665 static void target_complete_failure_work(struct work_struct *work)
666 {
667 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
668 
669 	transport_generic_request_failure(cmd,
670 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
671 }
672 
673 /*
674  * Used when asking transport to copy Sense Data from the underlying
675  * Linux/SCSI struct scsi_cmnd
676  */
677 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
678 {
679 	struct se_device *dev = cmd->se_dev;
680 
681 	WARN_ON(!cmd->se_lun);
682 
683 	if (!dev)
684 		return NULL;
685 
686 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
687 		return NULL;
688 
689 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
690 
691 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
692 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
693 	return cmd->sense_buffer;
694 }
695 
696 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
697 {
698 	struct se_device *dev = cmd->se_dev;
699 	int success = scsi_status == GOOD;
700 	unsigned long flags;
701 
702 	cmd->scsi_status = scsi_status;
703 
704 
705 	spin_lock_irqsave(&cmd->t_state_lock, flags);
706 	cmd->transport_state &= ~CMD_T_BUSY;
707 
708 	if (dev && dev->transport->transport_complete) {
709 		dev->transport->transport_complete(cmd,
710 				cmd->t_data_sg,
711 				transport_get_sense_buffer(cmd));
712 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
713 			success = 1;
714 	}
715 
716 	/*
717 	 * See if we are waiting to complete for an exception condition.
718 	 */
719 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
720 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
721 		complete(&cmd->task_stop_comp);
722 		return;
723 	}
724 
725 	/*
726 	 * Check for case where an explicit ABORT_TASK has been received
727 	 * and transport_wait_for_tasks() will be waiting for completion..
728 	 */
729 	if (cmd->transport_state & CMD_T_ABORTED &&
730 	    cmd->transport_state & CMD_T_STOP) {
731 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
732 		complete_all(&cmd->t_transport_stop_comp);
733 		return;
734 	} else if (!success) {
735 		INIT_WORK(&cmd->work, target_complete_failure_work);
736 	} else {
737 		INIT_WORK(&cmd->work, target_complete_ok_work);
738 	}
739 
740 	cmd->t_state = TRANSPORT_COMPLETE;
741 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
742 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
743 
744 	queue_work(target_completion_wq, &cmd->work);
745 }
746 EXPORT_SYMBOL(target_complete_cmd);
747 
748 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
749 {
750 	if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
751 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
752 			cmd->residual_count += cmd->data_length - length;
753 		} else {
754 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
755 			cmd->residual_count = cmd->data_length - length;
756 		}
757 
758 		cmd->data_length = length;
759 	}
760 
761 	target_complete_cmd(cmd, scsi_status);
762 }
763 EXPORT_SYMBOL(target_complete_cmd_with_length);
764 
765 static void target_add_to_state_list(struct se_cmd *cmd)
766 {
767 	struct se_device *dev = cmd->se_dev;
768 	unsigned long flags;
769 
770 	spin_lock_irqsave(&dev->execute_task_lock, flags);
771 	if (!cmd->state_active) {
772 		list_add_tail(&cmd->state_list, &dev->state_list);
773 		cmd->state_active = true;
774 	}
775 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
776 }
777 
778 /*
779  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
780  */
781 static void transport_write_pending_qf(struct se_cmd *cmd);
782 static void transport_complete_qf(struct se_cmd *cmd);
783 
784 void target_qf_do_work(struct work_struct *work)
785 {
786 	struct se_device *dev = container_of(work, struct se_device,
787 					qf_work_queue);
788 	LIST_HEAD(qf_cmd_list);
789 	struct se_cmd *cmd, *cmd_tmp;
790 
791 	spin_lock_irq(&dev->qf_cmd_lock);
792 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
793 	spin_unlock_irq(&dev->qf_cmd_lock);
794 
795 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
796 		list_del(&cmd->se_qf_node);
797 		atomic_dec_mb(&dev->dev_qf_count);
798 
799 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
800 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
801 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
802 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
803 			: "UNKNOWN");
804 
805 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
806 			transport_write_pending_qf(cmd);
807 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
808 			transport_complete_qf(cmd);
809 	}
810 }
811 
812 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
813 {
814 	switch (cmd->data_direction) {
815 	case DMA_NONE:
816 		return "NONE";
817 	case DMA_FROM_DEVICE:
818 		return "READ";
819 	case DMA_TO_DEVICE:
820 		return "WRITE";
821 	case DMA_BIDIRECTIONAL:
822 		return "BIDI";
823 	default:
824 		break;
825 	}
826 
827 	return "UNKNOWN";
828 }
829 
830 void transport_dump_dev_state(
831 	struct se_device *dev,
832 	char *b,
833 	int *bl)
834 {
835 	*bl += sprintf(b + *bl, "Status: ");
836 	if (dev->export_count)
837 		*bl += sprintf(b + *bl, "ACTIVATED");
838 	else
839 		*bl += sprintf(b + *bl, "DEACTIVATED");
840 
841 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
842 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
843 		dev->dev_attrib.block_size,
844 		dev->dev_attrib.hw_max_sectors);
845 	*bl += sprintf(b + *bl, "        ");
846 }
847 
848 void transport_dump_vpd_proto_id(
849 	struct t10_vpd *vpd,
850 	unsigned char *p_buf,
851 	int p_buf_len)
852 {
853 	unsigned char buf[VPD_TMP_BUF_SIZE];
854 	int len;
855 
856 	memset(buf, 0, VPD_TMP_BUF_SIZE);
857 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
858 
859 	switch (vpd->protocol_identifier) {
860 	case 0x00:
861 		sprintf(buf+len, "Fibre Channel\n");
862 		break;
863 	case 0x10:
864 		sprintf(buf+len, "Parallel SCSI\n");
865 		break;
866 	case 0x20:
867 		sprintf(buf+len, "SSA\n");
868 		break;
869 	case 0x30:
870 		sprintf(buf+len, "IEEE 1394\n");
871 		break;
872 	case 0x40:
873 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
874 				" Protocol\n");
875 		break;
876 	case 0x50:
877 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
878 		break;
879 	case 0x60:
880 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
881 		break;
882 	case 0x70:
883 		sprintf(buf+len, "Automation/Drive Interface Transport"
884 				" Protocol\n");
885 		break;
886 	case 0x80:
887 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
888 		break;
889 	default:
890 		sprintf(buf+len, "Unknown 0x%02x\n",
891 				vpd->protocol_identifier);
892 		break;
893 	}
894 
895 	if (p_buf)
896 		strncpy(p_buf, buf, p_buf_len);
897 	else
898 		pr_debug("%s", buf);
899 }
900 
901 void
902 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
903 {
904 	/*
905 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
906 	 *
907 	 * from spc3r23.pdf section 7.5.1
908 	 */
909 	 if (page_83[1] & 0x80) {
910 		vpd->protocol_identifier = (page_83[0] & 0xf0);
911 		vpd->protocol_identifier_set = 1;
912 		transport_dump_vpd_proto_id(vpd, NULL, 0);
913 	}
914 }
915 EXPORT_SYMBOL(transport_set_vpd_proto_id);
916 
917 int transport_dump_vpd_assoc(
918 	struct t10_vpd *vpd,
919 	unsigned char *p_buf,
920 	int p_buf_len)
921 {
922 	unsigned char buf[VPD_TMP_BUF_SIZE];
923 	int ret = 0;
924 	int len;
925 
926 	memset(buf, 0, VPD_TMP_BUF_SIZE);
927 	len = sprintf(buf, "T10 VPD Identifier Association: ");
928 
929 	switch (vpd->association) {
930 	case 0x00:
931 		sprintf(buf+len, "addressed logical unit\n");
932 		break;
933 	case 0x10:
934 		sprintf(buf+len, "target port\n");
935 		break;
936 	case 0x20:
937 		sprintf(buf+len, "SCSI target device\n");
938 		break;
939 	default:
940 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
941 		ret = -EINVAL;
942 		break;
943 	}
944 
945 	if (p_buf)
946 		strncpy(p_buf, buf, p_buf_len);
947 	else
948 		pr_debug("%s", buf);
949 
950 	return ret;
951 }
952 
953 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
954 {
955 	/*
956 	 * The VPD identification association..
957 	 *
958 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
959 	 */
960 	vpd->association = (page_83[1] & 0x30);
961 	return transport_dump_vpd_assoc(vpd, NULL, 0);
962 }
963 EXPORT_SYMBOL(transport_set_vpd_assoc);
964 
965 int transport_dump_vpd_ident_type(
966 	struct t10_vpd *vpd,
967 	unsigned char *p_buf,
968 	int p_buf_len)
969 {
970 	unsigned char buf[VPD_TMP_BUF_SIZE];
971 	int ret = 0;
972 	int len;
973 
974 	memset(buf, 0, VPD_TMP_BUF_SIZE);
975 	len = sprintf(buf, "T10 VPD Identifier Type: ");
976 
977 	switch (vpd->device_identifier_type) {
978 	case 0x00:
979 		sprintf(buf+len, "Vendor specific\n");
980 		break;
981 	case 0x01:
982 		sprintf(buf+len, "T10 Vendor ID based\n");
983 		break;
984 	case 0x02:
985 		sprintf(buf+len, "EUI-64 based\n");
986 		break;
987 	case 0x03:
988 		sprintf(buf+len, "NAA\n");
989 		break;
990 	case 0x04:
991 		sprintf(buf+len, "Relative target port identifier\n");
992 		break;
993 	case 0x08:
994 		sprintf(buf+len, "SCSI name string\n");
995 		break;
996 	default:
997 		sprintf(buf+len, "Unsupported: 0x%02x\n",
998 				vpd->device_identifier_type);
999 		ret = -EINVAL;
1000 		break;
1001 	}
1002 
1003 	if (p_buf) {
1004 		if (p_buf_len < strlen(buf)+1)
1005 			return -EINVAL;
1006 		strncpy(p_buf, buf, p_buf_len);
1007 	} else {
1008 		pr_debug("%s", buf);
1009 	}
1010 
1011 	return ret;
1012 }
1013 
1014 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1015 {
1016 	/*
1017 	 * The VPD identifier type..
1018 	 *
1019 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1020 	 */
1021 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1022 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1023 }
1024 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1025 
1026 int transport_dump_vpd_ident(
1027 	struct t10_vpd *vpd,
1028 	unsigned char *p_buf,
1029 	int p_buf_len)
1030 {
1031 	unsigned char buf[VPD_TMP_BUF_SIZE];
1032 	int ret = 0;
1033 
1034 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1035 
1036 	switch (vpd->device_identifier_code_set) {
1037 	case 0x01: /* Binary */
1038 		snprintf(buf, sizeof(buf),
1039 			"T10 VPD Binary Device Identifier: %s\n",
1040 			&vpd->device_identifier[0]);
1041 		break;
1042 	case 0x02: /* ASCII */
1043 		snprintf(buf, sizeof(buf),
1044 			"T10 VPD ASCII Device Identifier: %s\n",
1045 			&vpd->device_identifier[0]);
1046 		break;
1047 	case 0x03: /* UTF-8 */
1048 		snprintf(buf, sizeof(buf),
1049 			"T10 VPD UTF-8 Device Identifier: %s\n",
1050 			&vpd->device_identifier[0]);
1051 		break;
1052 	default:
1053 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1054 			" 0x%02x", vpd->device_identifier_code_set);
1055 		ret = -EINVAL;
1056 		break;
1057 	}
1058 
1059 	if (p_buf)
1060 		strncpy(p_buf, buf, p_buf_len);
1061 	else
1062 		pr_debug("%s", buf);
1063 
1064 	return ret;
1065 }
1066 
1067 int
1068 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1069 {
1070 	static const char hex_str[] = "0123456789abcdef";
1071 	int j = 0, i = 4; /* offset to start of the identifier */
1072 
1073 	/*
1074 	 * The VPD Code Set (encoding)
1075 	 *
1076 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1077 	 */
1078 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1079 	switch (vpd->device_identifier_code_set) {
1080 	case 0x01: /* Binary */
1081 		vpd->device_identifier[j++] =
1082 				hex_str[vpd->device_identifier_type];
1083 		while (i < (4 + page_83[3])) {
1084 			vpd->device_identifier[j++] =
1085 				hex_str[(page_83[i] & 0xf0) >> 4];
1086 			vpd->device_identifier[j++] =
1087 				hex_str[page_83[i] & 0x0f];
1088 			i++;
1089 		}
1090 		break;
1091 	case 0x02: /* ASCII */
1092 	case 0x03: /* UTF-8 */
1093 		while (i < (4 + page_83[3]))
1094 			vpd->device_identifier[j++] = page_83[i++];
1095 		break;
1096 	default:
1097 		break;
1098 	}
1099 
1100 	return transport_dump_vpd_ident(vpd, NULL, 0);
1101 }
1102 EXPORT_SYMBOL(transport_set_vpd_ident);
1103 
1104 sense_reason_t
1105 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1106 {
1107 	struct se_device *dev = cmd->se_dev;
1108 
1109 	if (cmd->unknown_data_length) {
1110 		cmd->data_length = size;
1111 	} else if (size != cmd->data_length) {
1112 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1113 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1114 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1115 				cmd->data_length, size, cmd->t_task_cdb[0]);
1116 
1117 		if (cmd->data_direction == DMA_TO_DEVICE) {
1118 			pr_err("Rejecting underflow/overflow"
1119 					" WRITE data\n");
1120 			return TCM_INVALID_CDB_FIELD;
1121 		}
1122 		/*
1123 		 * Reject READ_* or WRITE_* with overflow/underflow for
1124 		 * type SCF_SCSI_DATA_CDB.
1125 		 */
1126 		if (dev->dev_attrib.block_size != 512)  {
1127 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1128 				" CDB on non 512-byte sector setup subsystem"
1129 				" plugin: %s\n", dev->transport->name);
1130 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1131 			return TCM_INVALID_CDB_FIELD;
1132 		}
1133 		/*
1134 		 * For the overflow case keep the existing fabric provided
1135 		 * ->data_length.  Otherwise for the underflow case, reset
1136 		 * ->data_length to the smaller SCSI expected data transfer
1137 		 * length.
1138 		 */
1139 		if (size > cmd->data_length) {
1140 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1141 			cmd->residual_count = (size - cmd->data_length);
1142 		} else {
1143 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1144 			cmd->residual_count = (cmd->data_length - size);
1145 			cmd->data_length = size;
1146 		}
1147 	}
1148 
1149 	return 0;
1150 
1151 }
1152 
1153 /*
1154  * Used by fabric modules containing a local struct se_cmd within their
1155  * fabric dependent per I/O descriptor.
1156  */
1157 void transport_init_se_cmd(
1158 	struct se_cmd *cmd,
1159 	const struct target_core_fabric_ops *tfo,
1160 	struct se_session *se_sess,
1161 	u32 data_length,
1162 	int data_direction,
1163 	int task_attr,
1164 	unsigned char *sense_buffer)
1165 {
1166 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1167 	INIT_LIST_HEAD(&cmd->se_qf_node);
1168 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1169 	INIT_LIST_HEAD(&cmd->state_list);
1170 	init_completion(&cmd->t_transport_stop_comp);
1171 	init_completion(&cmd->cmd_wait_comp);
1172 	init_completion(&cmd->task_stop_comp);
1173 	spin_lock_init(&cmd->t_state_lock);
1174 	kref_init(&cmd->cmd_kref);
1175 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1176 
1177 	cmd->se_tfo = tfo;
1178 	cmd->se_sess = se_sess;
1179 	cmd->data_length = data_length;
1180 	cmd->data_direction = data_direction;
1181 	cmd->sam_task_attr = task_attr;
1182 	cmd->sense_buffer = sense_buffer;
1183 
1184 	cmd->state_active = false;
1185 }
1186 EXPORT_SYMBOL(transport_init_se_cmd);
1187 
1188 static sense_reason_t
1189 transport_check_alloc_task_attr(struct se_cmd *cmd)
1190 {
1191 	struct se_device *dev = cmd->se_dev;
1192 
1193 	/*
1194 	 * Check if SAM Task Attribute emulation is enabled for this
1195 	 * struct se_device storage object
1196 	 */
1197 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1198 		return 0;
1199 
1200 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1201 		pr_debug("SAM Task Attribute ACA"
1202 			" emulation is not supported\n");
1203 		return TCM_INVALID_CDB_FIELD;
1204 	}
1205 	/*
1206 	 * Used to determine when ORDERED commands should go from
1207 	 * Dormant to Active status.
1208 	 */
1209 	cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1210 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1211 			cmd->se_ordered_id, cmd->sam_task_attr,
1212 			dev->transport->name);
1213 	return 0;
1214 }
1215 
1216 sense_reason_t
1217 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1218 {
1219 	struct se_device *dev = cmd->se_dev;
1220 	sense_reason_t ret;
1221 
1222 	/*
1223 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1224 	 * for VARIABLE_LENGTH_CMD
1225 	 */
1226 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1227 		pr_err("Received SCSI CDB with command_size: %d that"
1228 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1229 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1230 		return TCM_INVALID_CDB_FIELD;
1231 	}
1232 	/*
1233 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1234 	 * allocate the additional extended CDB buffer now..  Otherwise
1235 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1236 	 */
1237 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1238 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1239 						GFP_KERNEL);
1240 		if (!cmd->t_task_cdb) {
1241 			pr_err("Unable to allocate cmd->t_task_cdb"
1242 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1243 				scsi_command_size(cdb),
1244 				(unsigned long)sizeof(cmd->__t_task_cdb));
1245 			return TCM_OUT_OF_RESOURCES;
1246 		}
1247 	} else
1248 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1249 	/*
1250 	 * Copy the original CDB into cmd->
1251 	 */
1252 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1253 
1254 	trace_target_sequencer_start(cmd);
1255 
1256 	/*
1257 	 * Check for an existing UNIT ATTENTION condition
1258 	 */
1259 	ret = target_scsi3_ua_check(cmd);
1260 	if (ret)
1261 		return ret;
1262 
1263 	ret = target_alua_state_check(cmd);
1264 	if (ret)
1265 		return ret;
1266 
1267 	ret = target_check_reservation(cmd);
1268 	if (ret) {
1269 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1270 		return ret;
1271 	}
1272 
1273 	ret = dev->transport->parse_cdb(cmd);
1274 	if (ret)
1275 		return ret;
1276 
1277 	ret = transport_check_alloc_task_attr(cmd);
1278 	if (ret)
1279 		return ret;
1280 
1281 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1282 
1283 	spin_lock(&cmd->se_lun->lun_sep_lock);
1284 	if (cmd->se_lun->lun_sep)
1285 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1286 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1287 	return 0;
1288 }
1289 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1290 
1291 /*
1292  * Used by fabric module frontends to queue tasks directly.
1293  * Many only be used from process context only
1294  */
1295 int transport_handle_cdb_direct(
1296 	struct se_cmd *cmd)
1297 {
1298 	sense_reason_t ret;
1299 
1300 	if (!cmd->se_lun) {
1301 		dump_stack();
1302 		pr_err("cmd->se_lun is NULL\n");
1303 		return -EINVAL;
1304 	}
1305 	if (in_interrupt()) {
1306 		dump_stack();
1307 		pr_err("transport_generic_handle_cdb cannot be called"
1308 				" from interrupt context\n");
1309 		return -EINVAL;
1310 	}
1311 	/*
1312 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1313 	 * outstanding descriptors are handled correctly during shutdown via
1314 	 * transport_wait_for_tasks()
1315 	 *
1316 	 * Also, we don't take cmd->t_state_lock here as we only expect
1317 	 * this to be called for initial descriptor submission.
1318 	 */
1319 	cmd->t_state = TRANSPORT_NEW_CMD;
1320 	cmd->transport_state |= CMD_T_ACTIVE;
1321 
1322 	/*
1323 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1324 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1325 	 * and call transport_generic_request_failure() if necessary..
1326 	 */
1327 	ret = transport_generic_new_cmd(cmd);
1328 	if (ret)
1329 		transport_generic_request_failure(cmd, ret);
1330 	return 0;
1331 }
1332 EXPORT_SYMBOL(transport_handle_cdb_direct);
1333 
1334 sense_reason_t
1335 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1336 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1337 {
1338 	if (!sgl || !sgl_count)
1339 		return 0;
1340 
1341 	/*
1342 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1343 	 * scatterlists already have been set to follow what the fabric
1344 	 * passes for the original expected data transfer length.
1345 	 */
1346 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1347 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1348 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1349 		return TCM_INVALID_CDB_FIELD;
1350 	}
1351 
1352 	cmd->t_data_sg = sgl;
1353 	cmd->t_data_nents = sgl_count;
1354 
1355 	if (sgl_bidi && sgl_bidi_count) {
1356 		cmd->t_bidi_data_sg = sgl_bidi;
1357 		cmd->t_bidi_data_nents = sgl_bidi_count;
1358 	}
1359 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1360 	return 0;
1361 }
1362 
1363 /*
1364  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1365  * 			 se_cmd + use pre-allocated SGL memory.
1366  *
1367  * @se_cmd: command descriptor to submit
1368  * @se_sess: associated se_sess for endpoint
1369  * @cdb: pointer to SCSI CDB
1370  * @sense: pointer to SCSI sense buffer
1371  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1372  * @data_length: fabric expected data transfer length
1373  * @task_addr: SAM task attribute
1374  * @data_dir: DMA data direction
1375  * @flags: flags for command submission from target_sc_flags_tables
1376  * @sgl: struct scatterlist memory for unidirectional mapping
1377  * @sgl_count: scatterlist count for unidirectional mapping
1378  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1379  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1380  * @sgl_prot: struct scatterlist memory protection information
1381  * @sgl_prot_count: scatterlist count for protection information
1382  *
1383  * Returns non zero to signal active I/O shutdown failure.  All other
1384  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1385  * but still return zero here.
1386  *
1387  * This may only be called from process context, and also currently
1388  * assumes internal allocation of fabric payload buffer by target-core.
1389  */
1390 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1391 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1392 		u32 data_length, int task_attr, int data_dir, int flags,
1393 		struct scatterlist *sgl, u32 sgl_count,
1394 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1395 		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1396 {
1397 	struct se_portal_group *se_tpg;
1398 	sense_reason_t rc;
1399 	int ret;
1400 
1401 	se_tpg = se_sess->se_tpg;
1402 	BUG_ON(!se_tpg);
1403 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1404 	BUG_ON(in_interrupt());
1405 	/*
1406 	 * Initialize se_cmd for target operation.  From this point
1407 	 * exceptions are handled by sending exception status via
1408 	 * target_core_fabric_ops->queue_status() callback
1409 	 */
1410 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1411 				data_length, data_dir, task_attr, sense);
1412 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1413 		se_cmd->unknown_data_length = 1;
1414 	/*
1415 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1416 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1417 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1418 	 * kref_put() to happen during fabric packet acknowledgement.
1419 	 */
1420 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1421 	if (ret)
1422 		return ret;
1423 	/*
1424 	 * Signal bidirectional data payloads to target-core
1425 	 */
1426 	if (flags & TARGET_SCF_BIDI_OP)
1427 		se_cmd->se_cmd_flags |= SCF_BIDI;
1428 	/*
1429 	 * Locate se_lun pointer and attach it to struct se_cmd
1430 	 */
1431 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1432 	if (rc) {
1433 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1434 		target_put_sess_cmd(se_sess, se_cmd);
1435 		return 0;
1436 	}
1437 
1438 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1439 	if (rc != 0) {
1440 		transport_generic_request_failure(se_cmd, rc);
1441 		return 0;
1442 	}
1443 
1444 	/*
1445 	 * Save pointers for SGLs containing protection information,
1446 	 * if present.
1447 	 */
1448 	if (sgl_prot_count) {
1449 		se_cmd->t_prot_sg = sgl_prot;
1450 		se_cmd->t_prot_nents = sgl_prot_count;
1451 	}
1452 
1453 	/*
1454 	 * When a non zero sgl_count has been passed perform SGL passthrough
1455 	 * mapping for pre-allocated fabric memory instead of having target
1456 	 * core perform an internal SGL allocation..
1457 	 */
1458 	if (sgl_count != 0) {
1459 		BUG_ON(!sgl);
1460 
1461 		/*
1462 		 * A work-around for tcm_loop as some userspace code via
1463 		 * scsi-generic do not memset their associated read buffers,
1464 		 * so go ahead and do that here for type non-data CDBs.  Also
1465 		 * note that this is currently guaranteed to be a single SGL
1466 		 * for this case by target core in target_setup_cmd_from_cdb()
1467 		 * -> transport_generic_cmd_sequencer().
1468 		 */
1469 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1470 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1471 			unsigned char *buf = NULL;
1472 
1473 			if (sgl)
1474 				buf = kmap(sg_page(sgl)) + sgl->offset;
1475 
1476 			if (buf) {
1477 				memset(buf, 0, sgl->length);
1478 				kunmap(sg_page(sgl));
1479 			}
1480 		}
1481 
1482 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1483 				sgl_bidi, sgl_bidi_count);
1484 		if (rc != 0) {
1485 			transport_generic_request_failure(se_cmd, rc);
1486 			return 0;
1487 		}
1488 	}
1489 
1490 	/*
1491 	 * Check if we need to delay processing because of ALUA
1492 	 * Active/NonOptimized primary access state..
1493 	 */
1494 	core_alua_check_nonop_delay(se_cmd);
1495 
1496 	transport_handle_cdb_direct(se_cmd);
1497 	return 0;
1498 }
1499 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1500 
1501 /*
1502  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1503  *
1504  * @se_cmd: command descriptor to submit
1505  * @se_sess: associated se_sess for endpoint
1506  * @cdb: pointer to SCSI CDB
1507  * @sense: pointer to SCSI sense buffer
1508  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1509  * @data_length: fabric expected data transfer length
1510  * @task_addr: SAM task attribute
1511  * @data_dir: DMA data direction
1512  * @flags: flags for command submission from target_sc_flags_tables
1513  *
1514  * Returns non zero to signal active I/O shutdown failure.  All other
1515  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1516  * but still return zero here.
1517  *
1518  * This may only be called from process context, and also currently
1519  * assumes internal allocation of fabric payload buffer by target-core.
1520  *
1521  * It also assumes interal target core SGL memory allocation.
1522  */
1523 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1524 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1525 		u32 data_length, int task_attr, int data_dir, int flags)
1526 {
1527 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1528 			unpacked_lun, data_length, task_attr, data_dir,
1529 			flags, NULL, 0, NULL, 0, NULL, 0);
1530 }
1531 EXPORT_SYMBOL(target_submit_cmd);
1532 
1533 static void target_complete_tmr_failure(struct work_struct *work)
1534 {
1535 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1536 
1537 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1538 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1539 
1540 	transport_cmd_check_stop_to_fabric(se_cmd);
1541 }
1542 
1543 /**
1544  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1545  *                     for TMR CDBs
1546  *
1547  * @se_cmd: command descriptor to submit
1548  * @se_sess: associated se_sess for endpoint
1549  * @sense: pointer to SCSI sense buffer
1550  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1551  * @fabric_context: fabric context for TMR req
1552  * @tm_type: Type of TM request
1553  * @gfp: gfp type for caller
1554  * @tag: referenced task tag for TMR_ABORT_TASK
1555  * @flags: submit cmd flags
1556  *
1557  * Callable from all contexts.
1558  **/
1559 
1560 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1561 		unsigned char *sense, u32 unpacked_lun,
1562 		void *fabric_tmr_ptr, unsigned char tm_type,
1563 		gfp_t gfp, unsigned int tag, int flags)
1564 {
1565 	struct se_portal_group *se_tpg;
1566 	int ret;
1567 
1568 	se_tpg = se_sess->se_tpg;
1569 	BUG_ON(!se_tpg);
1570 
1571 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1572 			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1573 	/*
1574 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1575 	 * allocation failure.
1576 	 */
1577 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1578 	if (ret < 0)
1579 		return -ENOMEM;
1580 
1581 	if (tm_type == TMR_ABORT_TASK)
1582 		se_cmd->se_tmr_req->ref_task_tag = tag;
1583 
1584 	/* See target_submit_cmd for commentary */
1585 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1586 	if (ret) {
1587 		core_tmr_release_req(se_cmd->se_tmr_req);
1588 		return ret;
1589 	}
1590 
1591 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1592 	if (ret) {
1593 		/*
1594 		 * For callback during failure handling, push this work off
1595 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1596 		 */
1597 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1598 		schedule_work(&se_cmd->work);
1599 		return 0;
1600 	}
1601 	transport_generic_handle_tmr(se_cmd);
1602 	return 0;
1603 }
1604 EXPORT_SYMBOL(target_submit_tmr);
1605 
1606 /*
1607  * If the cmd is active, request it to be stopped and sleep until it
1608  * has completed.
1609  */
1610 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1611 	__releases(&cmd->t_state_lock)
1612 	__acquires(&cmd->t_state_lock)
1613 {
1614 	bool was_active = false;
1615 
1616 	if (cmd->transport_state & CMD_T_BUSY) {
1617 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1618 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1619 
1620 		pr_debug("cmd %p waiting to complete\n", cmd);
1621 		wait_for_completion(&cmd->task_stop_comp);
1622 		pr_debug("cmd %p stopped successfully\n", cmd);
1623 
1624 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1625 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1626 		cmd->transport_state &= ~CMD_T_BUSY;
1627 		was_active = true;
1628 	}
1629 
1630 	return was_active;
1631 }
1632 
1633 /*
1634  * Handle SAM-esque emulation for generic transport request failures.
1635  */
1636 void transport_generic_request_failure(struct se_cmd *cmd,
1637 		sense_reason_t sense_reason)
1638 {
1639 	int ret = 0;
1640 
1641 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1642 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1643 		cmd->t_task_cdb[0]);
1644 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1645 		cmd->se_tfo->get_cmd_state(cmd),
1646 		cmd->t_state, sense_reason);
1647 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1648 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1649 		(cmd->transport_state & CMD_T_STOP) != 0,
1650 		(cmd->transport_state & CMD_T_SENT) != 0);
1651 
1652 	/*
1653 	 * For SAM Task Attribute emulation for failed struct se_cmd
1654 	 */
1655 	transport_complete_task_attr(cmd);
1656 	/*
1657 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1658 	 * callback is expected to drop the per device ->caw_sem.
1659 	 */
1660 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1661 	     cmd->transport_complete_callback)
1662 		cmd->transport_complete_callback(cmd, false);
1663 
1664 	switch (sense_reason) {
1665 	case TCM_NON_EXISTENT_LUN:
1666 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1667 	case TCM_INVALID_CDB_FIELD:
1668 	case TCM_INVALID_PARAMETER_LIST:
1669 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1670 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1671 	case TCM_UNKNOWN_MODE_PAGE:
1672 	case TCM_WRITE_PROTECTED:
1673 	case TCM_ADDRESS_OUT_OF_RANGE:
1674 	case TCM_CHECK_CONDITION_ABORT_CMD:
1675 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1676 	case TCM_CHECK_CONDITION_NOT_READY:
1677 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1678 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1679 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1680 		break;
1681 	case TCM_OUT_OF_RESOURCES:
1682 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1683 		break;
1684 	case TCM_RESERVATION_CONFLICT:
1685 		/*
1686 		 * No SENSE Data payload for this case, set SCSI Status
1687 		 * and queue the response to $FABRIC_MOD.
1688 		 *
1689 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1690 		 */
1691 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1692 		/*
1693 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1694 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1695 		 * CONFLICT STATUS.
1696 		 *
1697 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1698 		 */
1699 		if (cmd->se_sess &&
1700 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1701 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1702 				cmd->orig_fe_lun, 0x2C,
1703 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1704 
1705 		trace_target_cmd_complete(cmd);
1706 		ret = cmd->se_tfo-> queue_status(cmd);
1707 		if (ret == -EAGAIN || ret == -ENOMEM)
1708 			goto queue_full;
1709 		goto check_stop;
1710 	default:
1711 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1712 			cmd->t_task_cdb[0], sense_reason);
1713 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1714 		break;
1715 	}
1716 
1717 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1718 	if (ret == -EAGAIN || ret == -ENOMEM)
1719 		goto queue_full;
1720 
1721 check_stop:
1722 	transport_lun_remove_cmd(cmd);
1723 	if (!transport_cmd_check_stop_to_fabric(cmd))
1724 		;
1725 	return;
1726 
1727 queue_full:
1728 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1729 	transport_handle_queue_full(cmd, cmd->se_dev);
1730 }
1731 EXPORT_SYMBOL(transport_generic_request_failure);
1732 
1733 void __target_execute_cmd(struct se_cmd *cmd)
1734 {
1735 	sense_reason_t ret;
1736 
1737 	if (cmd->execute_cmd) {
1738 		ret = cmd->execute_cmd(cmd);
1739 		if (ret) {
1740 			spin_lock_irq(&cmd->t_state_lock);
1741 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1742 			spin_unlock_irq(&cmd->t_state_lock);
1743 
1744 			transport_generic_request_failure(cmd, ret);
1745 		}
1746 	}
1747 }
1748 
1749 static int target_write_prot_action(struct se_cmd *cmd)
1750 {
1751 	u32 sectors;
1752 	/*
1753 	 * Perform WRITE_INSERT of PI using software emulation when backend
1754 	 * device has PI enabled, if the transport has not already generated
1755 	 * PI using hardware WRITE_INSERT offload.
1756 	 */
1757 	switch (cmd->prot_op) {
1758 	case TARGET_PROT_DOUT_INSERT:
1759 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1760 			sbc_dif_generate(cmd);
1761 		break;
1762 	case TARGET_PROT_DOUT_STRIP:
1763 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1764 			break;
1765 
1766 		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1767 		cmd->pi_err = sbc_dif_verify_write(cmd, cmd->t_task_lba,
1768 						   sectors, 0, NULL, 0);
1769 		if (unlikely(cmd->pi_err)) {
1770 			spin_lock_irq(&cmd->t_state_lock);
1771 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1772 			spin_unlock_irq(&cmd->t_state_lock);
1773 			transport_generic_request_failure(cmd, cmd->pi_err);
1774 			return -1;
1775 		}
1776 		break;
1777 	default:
1778 		break;
1779 	}
1780 
1781 	return 0;
1782 }
1783 
1784 static bool target_handle_task_attr(struct se_cmd *cmd)
1785 {
1786 	struct se_device *dev = cmd->se_dev;
1787 
1788 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1789 		return false;
1790 
1791 	/*
1792 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1793 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1794 	 */
1795 	switch (cmd->sam_task_attr) {
1796 	case TCM_HEAD_TAG:
1797 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1798 			 "se_ordered_id: %u\n",
1799 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1800 		return false;
1801 	case TCM_ORDERED_TAG:
1802 		atomic_inc_mb(&dev->dev_ordered_sync);
1803 
1804 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1805 			 " se_ordered_id: %u\n",
1806 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1807 
1808 		/*
1809 		 * Execute an ORDERED command if no other older commands
1810 		 * exist that need to be completed first.
1811 		 */
1812 		if (!atomic_read(&dev->simple_cmds))
1813 			return false;
1814 		break;
1815 	default:
1816 		/*
1817 		 * For SIMPLE and UNTAGGED Task Attribute commands
1818 		 */
1819 		atomic_inc_mb(&dev->simple_cmds);
1820 		break;
1821 	}
1822 
1823 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1824 		return false;
1825 
1826 	spin_lock(&dev->delayed_cmd_lock);
1827 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1828 	spin_unlock(&dev->delayed_cmd_lock);
1829 
1830 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1831 		" delayed CMD list, se_ordered_id: %u\n",
1832 		cmd->t_task_cdb[0], cmd->sam_task_attr,
1833 		cmd->se_ordered_id);
1834 	return true;
1835 }
1836 
1837 void target_execute_cmd(struct se_cmd *cmd)
1838 {
1839 	/*
1840 	 * If the received CDB has aleady been aborted stop processing it here.
1841 	 */
1842 	if (transport_check_aborted_status(cmd, 1))
1843 		return;
1844 
1845 	/*
1846 	 * Determine if frontend context caller is requesting the stopping of
1847 	 * this command for frontend exceptions.
1848 	 */
1849 	spin_lock_irq(&cmd->t_state_lock);
1850 	if (cmd->transport_state & CMD_T_STOP) {
1851 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1852 			__func__, __LINE__,
1853 			cmd->se_tfo->get_task_tag(cmd));
1854 
1855 		spin_unlock_irq(&cmd->t_state_lock);
1856 		complete_all(&cmd->t_transport_stop_comp);
1857 		return;
1858 	}
1859 
1860 	cmd->t_state = TRANSPORT_PROCESSING;
1861 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1862 	spin_unlock_irq(&cmd->t_state_lock);
1863 
1864 	if (target_write_prot_action(cmd))
1865 		return;
1866 
1867 	if (target_handle_task_attr(cmd)) {
1868 		spin_lock_irq(&cmd->t_state_lock);
1869 		cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1870 		spin_unlock_irq(&cmd->t_state_lock);
1871 		return;
1872 	}
1873 
1874 	__target_execute_cmd(cmd);
1875 }
1876 EXPORT_SYMBOL(target_execute_cmd);
1877 
1878 /*
1879  * Process all commands up to the last received ORDERED task attribute which
1880  * requires another blocking boundary
1881  */
1882 static void target_restart_delayed_cmds(struct se_device *dev)
1883 {
1884 	for (;;) {
1885 		struct se_cmd *cmd;
1886 
1887 		spin_lock(&dev->delayed_cmd_lock);
1888 		if (list_empty(&dev->delayed_cmd_list)) {
1889 			spin_unlock(&dev->delayed_cmd_lock);
1890 			break;
1891 		}
1892 
1893 		cmd = list_entry(dev->delayed_cmd_list.next,
1894 				 struct se_cmd, se_delayed_node);
1895 		list_del(&cmd->se_delayed_node);
1896 		spin_unlock(&dev->delayed_cmd_lock);
1897 
1898 		__target_execute_cmd(cmd);
1899 
1900 		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1901 			break;
1902 	}
1903 }
1904 
1905 /*
1906  * Called from I/O completion to determine which dormant/delayed
1907  * and ordered cmds need to have their tasks added to the execution queue.
1908  */
1909 static void transport_complete_task_attr(struct se_cmd *cmd)
1910 {
1911 	struct se_device *dev = cmd->se_dev;
1912 
1913 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1914 		return;
1915 
1916 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1917 		atomic_dec_mb(&dev->simple_cmds);
1918 		dev->dev_cur_ordered_id++;
1919 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1920 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1921 			cmd->se_ordered_id);
1922 	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1923 		dev->dev_cur_ordered_id++;
1924 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1925 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1926 			cmd->se_ordered_id);
1927 	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1928 		atomic_dec_mb(&dev->dev_ordered_sync);
1929 
1930 		dev->dev_cur_ordered_id++;
1931 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1932 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1933 	}
1934 
1935 	target_restart_delayed_cmds(dev);
1936 }
1937 
1938 static void transport_complete_qf(struct se_cmd *cmd)
1939 {
1940 	int ret = 0;
1941 
1942 	transport_complete_task_attr(cmd);
1943 
1944 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1945 		trace_target_cmd_complete(cmd);
1946 		ret = cmd->se_tfo->queue_status(cmd);
1947 		goto out;
1948 	}
1949 
1950 	switch (cmd->data_direction) {
1951 	case DMA_FROM_DEVICE:
1952 		trace_target_cmd_complete(cmd);
1953 		ret = cmd->se_tfo->queue_data_in(cmd);
1954 		break;
1955 	case DMA_TO_DEVICE:
1956 		if (cmd->se_cmd_flags & SCF_BIDI) {
1957 			ret = cmd->se_tfo->queue_data_in(cmd);
1958 			break;
1959 		}
1960 		/* Fall through for DMA_TO_DEVICE */
1961 	case DMA_NONE:
1962 		trace_target_cmd_complete(cmd);
1963 		ret = cmd->se_tfo->queue_status(cmd);
1964 		break;
1965 	default:
1966 		break;
1967 	}
1968 
1969 out:
1970 	if (ret < 0) {
1971 		transport_handle_queue_full(cmd, cmd->se_dev);
1972 		return;
1973 	}
1974 	transport_lun_remove_cmd(cmd);
1975 	transport_cmd_check_stop_to_fabric(cmd);
1976 }
1977 
1978 static void transport_handle_queue_full(
1979 	struct se_cmd *cmd,
1980 	struct se_device *dev)
1981 {
1982 	spin_lock_irq(&dev->qf_cmd_lock);
1983 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1984 	atomic_inc_mb(&dev->dev_qf_count);
1985 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1986 
1987 	schedule_work(&cmd->se_dev->qf_work_queue);
1988 }
1989 
1990 static bool target_read_prot_action(struct se_cmd *cmd)
1991 {
1992 	sense_reason_t rc;
1993 
1994 	switch (cmd->prot_op) {
1995 	case TARGET_PROT_DIN_STRIP:
1996 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
1997 			rc = sbc_dif_read_strip(cmd);
1998 			if (rc) {
1999 				cmd->pi_err = rc;
2000 				return true;
2001 			}
2002 		}
2003 		break;
2004 	case TARGET_PROT_DIN_INSERT:
2005 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2006 			break;
2007 
2008 		sbc_dif_generate(cmd);
2009 		break;
2010 	default:
2011 		break;
2012 	}
2013 
2014 	return false;
2015 }
2016 
2017 static void target_complete_ok_work(struct work_struct *work)
2018 {
2019 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2020 	int ret;
2021 
2022 	/*
2023 	 * Check if we need to move delayed/dormant tasks from cmds on the
2024 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2025 	 * Attribute.
2026 	 */
2027 	transport_complete_task_attr(cmd);
2028 
2029 	/*
2030 	 * Check to schedule QUEUE_FULL work, or execute an existing
2031 	 * cmd->transport_qf_callback()
2032 	 */
2033 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2034 		schedule_work(&cmd->se_dev->qf_work_queue);
2035 
2036 	/*
2037 	 * Check if we need to send a sense buffer from
2038 	 * the struct se_cmd in question.
2039 	 */
2040 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2041 		WARN_ON(!cmd->scsi_status);
2042 		ret = transport_send_check_condition_and_sense(
2043 					cmd, 0, 1);
2044 		if (ret == -EAGAIN || ret == -ENOMEM)
2045 			goto queue_full;
2046 
2047 		transport_lun_remove_cmd(cmd);
2048 		transport_cmd_check_stop_to_fabric(cmd);
2049 		return;
2050 	}
2051 	/*
2052 	 * Check for a callback, used by amongst other things
2053 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2054 	 */
2055 	if (cmd->transport_complete_callback) {
2056 		sense_reason_t rc;
2057 
2058 		rc = cmd->transport_complete_callback(cmd, true);
2059 		if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
2060 			if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2061 			    !cmd->data_length)
2062 				goto queue_rsp;
2063 
2064 			return;
2065 		} else if (rc) {
2066 			ret = transport_send_check_condition_and_sense(cmd,
2067 						rc, 0);
2068 			if (ret == -EAGAIN || ret == -ENOMEM)
2069 				goto queue_full;
2070 
2071 			transport_lun_remove_cmd(cmd);
2072 			transport_cmd_check_stop_to_fabric(cmd);
2073 			return;
2074 		}
2075 	}
2076 
2077 queue_rsp:
2078 	switch (cmd->data_direction) {
2079 	case DMA_FROM_DEVICE:
2080 		spin_lock(&cmd->se_lun->lun_sep_lock);
2081 		if (cmd->se_lun->lun_sep) {
2082 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2083 					cmd->data_length;
2084 		}
2085 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2086 		/*
2087 		 * Perform READ_STRIP of PI using software emulation when
2088 		 * backend had PI enabled, if the transport will not be
2089 		 * performing hardware READ_STRIP offload.
2090 		 */
2091 		if (target_read_prot_action(cmd)) {
2092 			ret = transport_send_check_condition_and_sense(cmd,
2093 						cmd->pi_err, 0);
2094 			if (ret == -EAGAIN || ret == -ENOMEM)
2095 				goto queue_full;
2096 
2097 			transport_lun_remove_cmd(cmd);
2098 			transport_cmd_check_stop_to_fabric(cmd);
2099 			return;
2100 		}
2101 
2102 		trace_target_cmd_complete(cmd);
2103 		ret = cmd->se_tfo->queue_data_in(cmd);
2104 		if (ret == -EAGAIN || ret == -ENOMEM)
2105 			goto queue_full;
2106 		break;
2107 	case DMA_TO_DEVICE:
2108 		spin_lock(&cmd->se_lun->lun_sep_lock);
2109 		if (cmd->se_lun->lun_sep) {
2110 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2111 				cmd->data_length;
2112 		}
2113 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2114 		/*
2115 		 * Check if we need to send READ payload for BIDI-COMMAND
2116 		 */
2117 		if (cmd->se_cmd_flags & SCF_BIDI) {
2118 			spin_lock(&cmd->se_lun->lun_sep_lock);
2119 			if (cmd->se_lun->lun_sep) {
2120 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2121 					cmd->data_length;
2122 			}
2123 			spin_unlock(&cmd->se_lun->lun_sep_lock);
2124 			ret = cmd->se_tfo->queue_data_in(cmd);
2125 			if (ret == -EAGAIN || ret == -ENOMEM)
2126 				goto queue_full;
2127 			break;
2128 		}
2129 		/* Fall through for DMA_TO_DEVICE */
2130 	case DMA_NONE:
2131 		trace_target_cmd_complete(cmd);
2132 		ret = cmd->se_tfo->queue_status(cmd);
2133 		if (ret == -EAGAIN || ret == -ENOMEM)
2134 			goto queue_full;
2135 		break;
2136 	default:
2137 		break;
2138 	}
2139 
2140 	transport_lun_remove_cmd(cmd);
2141 	transport_cmd_check_stop_to_fabric(cmd);
2142 	return;
2143 
2144 queue_full:
2145 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2146 		" data_direction: %d\n", cmd, cmd->data_direction);
2147 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2148 	transport_handle_queue_full(cmd, cmd->se_dev);
2149 }
2150 
2151 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2152 {
2153 	struct scatterlist *sg;
2154 	int count;
2155 
2156 	for_each_sg(sgl, sg, nents, count)
2157 		__free_page(sg_page(sg));
2158 
2159 	kfree(sgl);
2160 }
2161 
2162 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2163 {
2164 	/*
2165 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2166 	 * emulation, and free + reset pointers if necessary..
2167 	 */
2168 	if (!cmd->t_data_sg_orig)
2169 		return;
2170 
2171 	kfree(cmd->t_data_sg);
2172 	cmd->t_data_sg = cmd->t_data_sg_orig;
2173 	cmd->t_data_sg_orig = NULL;
2174 	cmd->t_data_nents = cmd->t_data_nents_orig;
2175 	cmd->t_data_nents_orig = 0;
2176 }
2177 
2178 static inline void transport_free_pages(struct se_cmd *cmd)
2179 {
2180 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2181 		/*
2182 		 * Release special case READ buffer payload required for
2183 		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2184 		 */
2185 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2186 			transport_free_sgl(cmd->t_bidi_data_sg,
2187 					   cmd->t_bidi_data_nents);
2188 			cmd->t_bidi_data_sg = NULL;
2189 			cmd->t_bidi_data_nents = 0;
2190 		}
2191 		transport_reset_sgl_orig(cmd);
2192 		return;
2193 	}
2194 	transport_reset_sgl_orig(cmd);
2195 
2196 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2197 	cmd->t_data_sg = NULL;
2198 	cmd->t_data_nents = 0;
2199 
2200 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2201 	cmd->t_bidi_data_sg = NULL;
2202 	cmd->t_bidi_data_nents = 0;
2203 
2204 	transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2205 	cmd->t_prot_sg = NULL;
2206 	cmd->t_prot_nents = 0;
2207 }
2208 
2209 /**
2210  * transport_release_cmd - free a command
2211  * @cmd:       command to free
2212  *
2213  * This routine unconditionally frees a command, and reference counting
2214  * or list removal must be done in the caller.
2215  */
2216 static int transport_release_cmd(struct se_cmd *cmd)
2217 {
2218 	BUG_ON(!cmd->se_tfo);
2219 
2220 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2221 		core_tmr_release_req(cmd->se_tmr_req);
2222 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2223 		kfree(cmd->t_task_cdb);
2224 	/*
2225 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2226 	 * the kref and call ->release_cmd() in kref callback.
2227 	 */
2228 	return target_put_sess_cmd(cmd->se_sess, cmd);
2229 }
2230 
2231 /**
2232  * transport_put_cmd - release a reference to a command
2233  * @cmd:       command to release
2234  *
2235  * This routine releases our reference to the command and frees it if possible.
2236  */
2237 static int transport_put_cmd(struct se_cmd *cmd)
2238 {
2239 	transport_free_pages(cmd);
2240 	return transport_release_cmd(cmd);
2241 }
2242 
2243 void *transport_kmap_data_sg(struct se_cmd *cmd)
2244 {
2245 	struct scatterlist *sg = cmd->t_data_sg;
2246 	struct page **pages;
2247 	int i;
2248 
2249 	/*
2250 	 * We need to take into account a possible offset here for fabrics like
2251 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2252 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2253 	 */
2254 	if (!cmd->t_data_nents)
2255 		return NULL;
2256 
2257 	BUG_ON(!sg);
2258 	if (cmd->t_data_nents == 1)
2259 		return kmap(sg_page(sg)) + sg->offset;
2260 
2261 	/* >1 page. use vmap */
2262 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2263 	if (!pages)
2264 		return NULL;
2265 
2266 	/* convert sg[] to pages[] */
2267 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2268 		pages[i] = sg_page(sg);
2269 	}
2270 
2271 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2272 	kfree(pages);
2273 	if (!cmd->t_data_vmap)
2274 		return NULL;
2275 
2276 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2277 }
2278 EXPORT_SYMBOL(transport_kmap_data_sg);
2279 
2280 void transport_kunmap_data_sg(struct se_cmd *cmd)
2281 {
2282 	if (!cmd->t_data_nents) {
2283 		return;
2284 	} else if (cmd->t_data_nents == 1) {
2285 		kunmap(sg_page(cmd->t_data_sg));
2286 		return;
2287 	}
2288 
2289 	vunmap(cmd->t_data_vmap);
2290 	cmd->t_data_vmap = NULL;
2291 }
2292 EXPORT_SYMBOL(transport_kunmap_data_sg);
2293 
2294 int
2295 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2296 		 bool zero_page)
2297 {
2298 	struct scatterlist *sg;
2299 	struct page *page;
2300 	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2301 	unsigned int nent;
2302 	int i = 0;
2303 
2304 	nent = DIV_ROUND_UP(length, PAGE_SIZE);
2305 	sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2306 	if (!sg)
2307 		return -ENOMEM;
2308 
2309 	sg_init_table(sg, nent);
2310 
2311 	while (length) {
2312 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2313 		page = alloc_page(GFP_KERNEL | zero_flag);
2314 		if (!page)
2315 			goto out;
2316 
2317 		sg_set_page(&sg[i], page, page_len, 0);
2318 		length -= page_len;
2319 		i++;
2320 	}
2321 	*sgl = sg;
2322 	*nents = nent;
2323 	return 0;
2324 
2325 out:
2326 	while (i > 0) {
2327 		i--;
2328 		__free_page(sg_page(&sg[i]));
2329 	}
2330 	kfree(sg);
2331 	return -ENOMEM;
2332 }
2333 
2334 /*
2335  * Allocate any required resources to execute the command.  For writes we
2336  * might not have the payload yet, so notify the fabric via a call to
2337  * ->write_pending instead. Otherwise place it on the execution queue.
2338  */
2339 sense_reason_t
2340 transport_generic_new_cmd(struct se_cmd *cmd)
2341 {
2342 	int ret = 0;
2343 	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2344 
2345 	/*
2346 	 * Determine is the TCM fabric module has already allocated physical
2347 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2348 	 * beforehand.
2349 	 */
2350 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2351 	    cmd->data_length) {
2352 
2353 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2354 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2355 			u32 bidi_length;
2356 
2357 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2358 				bidi_length = cmd->t_task_nolb *
2359 					      cmd->se_dev->dev_attrib.block_size;
2360 			else
2361 				bidi_length = cmd->data_length;
2362 
2363 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2364 					       &cmd->t_bidi_data_nents,
2365 					       bidi_length, zero_flag);
2366 			if (ret < 0)
2367 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2368 		}
2369 
2370 		if (cmd->prot_op != TARGET_PROT_NORMAL) {
2371 			ret = target_alloc_sgl(&cmd->t_prot_sg,
2372 					       &cmd->t_prot_nents,
2373 					       cmd->prot_length, true);
2374 			if (ret < 0)
2375 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2376 		}
2377 
2378 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2379 				       cmd->data_length, zero_flag);
2380 		if (ret < 0)
2381 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2382 	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2383 		    cmd->data_length) {
2384 		/*
2385 		 * Special case for COMPARE_AND_WRITE with fabrics
2386 		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2387 		 */
2388 		u32 caw_length = cmd->t_task_nolb *
2389 				 cmd->se_dev->dev_attrib.block_size;
2390 
2391 		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2392 				       &cmd->t_bidi_data_nents,
2393 				       caw_length, zero_flag);
2394 		if (ret < 0)
2395 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2396 	}
2397 	/*
2398 	 * If this command is not a write we can execute it right here,
2399 	 * for write buffers we need to notify the fabric driver first
2400 	 * and let it call back once the write buffers are ready.
2401 	 */
2402 	target_add_to_state_list(cmd);
2403 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2404 		target_execute_cmd(cmd);
2405 		return 0;
2406 	}
2407 	transport_cmd_check_stop(cmd, false, true);
2408 
2409 	ret = cmd->se_tfo->write_pending(cmd);
2410 	if (ret == -EAGAIN || ret == -ENOMEM)
2411 		goto queue_full;
2412 
2413 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2414 	WARN_ON(ret);
2415 
2416 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2417 
2418 queue_full:
2419 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2420 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2421 	transport_handle_queue_full(cmd, cmd->se_dev);
2422 	return 0;
2423 }
2424 EXPORT_SYMBOL(transport_generic_new_cmd);
2425 
2426 static void transport_write_pending_qf(struct se_cmd *cmd)
2427 {
2428 	int ret;
2429 
2430 	ret = cmd->se_tfo->write_pending(cmd);
2431 	if (ret == -EAGAIN || ret == -ENOMEM) {
2432 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2433 			 cmd);
2434 		transport_handle_queue_full(cmd, cmd->se_dev);
2435 	}
2436 }
2437 
2438 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2439 {
2440 	unsigned long flags;
2441 	int ret = 0;
2442 
2443 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2444 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2445 			 transport_wait_for_tasks(cmd);
2446 
2447 		ret = transport_release_cmd(cmd);
2448 	} else {
2449 		if (wait_for_tasks)
2450 			transport_wait_for_tasks(cmd);
2451 		/*
2452 		 * Handle WRITE failure case where transport_generic_new_cmd()
2453 		 * has already added se_cmd to state_list, but fabric has
2454 		 * failed command before I/O submission.
2455 		 */
2456 		if (cmd->state_active) {
2457 			spin_lock_irqsave(&cmd->t_state_lock, flags);
2458 			target_remove_from_state_list(cmd);
2459 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2460 		}
2461 
2462 		if (cmd->se_lun)
2463 			transport_lun_remove_cmd(cmd);
2464 
2465 		ret = transport_put_cmd(cmd);
2466 	}
2467 	return ret;
2468 }
2469 EXPORT_SYMBOL(transport_generic_free_cmd);
2470 
2471 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2472  * @se_sess:	session to reference
2473  * @se_cmd:	command descriptor to add
2474  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2475  */
2476 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2477 			       bool ack_kref)
2478 {
2479 	unsigned long flags;
2480 	int ret = 0;
2481 
2482 	/*
2483 	 * Add a second kref if the fabric caller is expecting to handle
2484 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2485 	 * invocations before se_cmd descriptor release.
2486 	 */
2487 	if (ack_kref)
2488 		kref_get(&se_cmd->cmd_kref);
2489 
2490 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2491 	if (se_sess->sess_tearing_down) {
2492 		ret = -ESHUTDOWN;
2493 		goto out;
2494 	}
2495 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2496 out:
2497 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2498 
2499 	if (ret && ack_kref)
2500 		target_put_sess_cmd(se_sess, se_cmd);
2501 
2502 	return ret;
2503 }
2504 EXPORT_SYMBOL(target_get_sess_cmd);
2505 
2506 static void target_release_cmd_kref(struct kref *kref)
2507 		__releases(&se_cmd->se_sess->sess_cmd_lock)
2508 {
2509 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2510 	struct se_session *se_sess = se_cmd->se_sess;
2511 
2512 	if (list_empty(&se_cmd->se_cmd_list)) {
2513 		spin_unlock(&se_sess->sess_cmd_lock);
2514 		se_cmd->se_tfo->release_cmd(se_cmd);
2515 		return;
2516 	}
2517 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2518 		spin_unlock(&se_sess->sess_cmd_lock);
2519 		complete(&se_cmd->cmd_wait_comp);
2520 		return;
2521 	}
2522 	list_del(&se_cmd->se_cmd_list);
2523 	spin_unlock(&se_sess->sess_cmd_lock);
2524 
2525 	se_cmd->se_tfo->release_cmd(se_cmd);
2526 }
2527 
2528 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2529  * @se_sess:	session to reference
2530  * @se_cmd:	command descriptor to drop
2531  */
2532 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2533 {
2534 	if (!se_sess) {
2535 		se_cmd->se_tfo->release_cmd(se_cmd);
2536 		return 1;
2537 	}
2538 	return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2539 			&se_sess->sess_cmd_lock);
2540 }
2541 EXPORT_SYMBOL(target_put_sess_cmd);
2542 
2543 /* target_sess_cmd_list_set_waiting - Flag all commands in
2544  *         sess_cmd_list to complete cmd_wait_comp.  Set
2545  *         sess_tearing_down so no more commands are queued.
2546  * @se_sess:	session to flag
2547  */
2548 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2549 {
2550 	struct se_cmd *se_cmd;
2551 	unsigned long flags;
2552 
2553 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2554 	if (se_sess->sess_tearing_down) {
2555 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2556 		return;
2557 	}
2558 	se_sess->sess_tearing_down = 1;
2559 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2560 
2561 	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2562 		se_cmd->cmd_wait_set = 1;
2563 
2564 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2565 }
2566 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2567 
2568 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2569  * @se_sess:    session to wait for active I/O
2570  */
2571 void target_wait_for_sess_cmds(struct se_session *se_sess)
2572 {
2573 	struct se_cmd *se_cmd, *tmp_cmd;
2574 	unsigned long flags;
2575 
2576 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2577 				&se_sess->sess_wait_list, se_cmd_list) {
2578 		list_del(&se_cmd->se_cmd_list);
2579 
2580 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2581 			" %d\n", se_cmd, se_cmd->t_state,
2582 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2583 
2584 		wait_for_completion(&se_cmd->cmd_wait_comp);
2585 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2586 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2587 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2588 
2589 		se_cmd->se_tfo->release_cmd(se_cmd);
2590 	}
2591 
2592 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2593 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2594 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2595 
2596 }
2597 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2598 
2599 static int transport_clear_lun_ref_thread(void *p)
2600 {
2601 	struct se_lun *lun = p;
2602 
2603 	percpu_ref_kill(&lun->lun_ref);
2604 
2605 	wait_for_completion(&lun->lun_ref_comp);
2606 	complete(&lun->lun_shutdown_comp);
2607 
2608 	return 0;
2609 }
2610 
2611 int transport_clear_lun_ref(struct se_lun *lun)
2612 {
2613 	struct task_struct *kt;
2614 
2615 	kt = kthread_run(transport_clear_lun_ref_thread, lun,
2616 			"tcm_cl_%u", lun->unpacked_lun);
2617 	if (IS_ERR(kt)) {
2618 		pr_err("Unable to start clear_lun thread\n");
2619 		return PTR_ERR(kt);
2620 	}
2621 	wait_for_completion(&lun->lun_shutdown_comp);
2622 
2623 	return 0;
2624 }
2625 
2626 /**
2627  * transport_wait_for_tasks - wait for completion to occur
2628  * @cmd:	command to wait
2629  *
2630  * Called from frontend fabric context to wait for storage engine
2631  * to pause and/or release frontend generated struct se_cmd.
2632  */
2633 bool transport_wait_for_tasks(struct se_cmd *cmd)
2634 {
2635 	unsigned long flags;
2636 
2637 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2638 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2639 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2640 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2641 		return false;
2642 	}
2643 
2644 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2645 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2646 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2647 		return false;
2648 	}
2649 
2650 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2651 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2652 		return false;
2653 	}
2654 
2655 	cmd->transport_state |= CMD_T_STOP;
2656 
2657 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2658 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2659 		cmd, cmd->se_tfo->get_task_tag(cmd),
2660 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2661 
2662 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2663 
2664 	wait_for_completion(&cmd->t_transport_stop_comp);
2665 
2666 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2667 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2668 
2669 	pr_debug("wait_for_tasks: Stopped wait_for_completion("
2670 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2671 		cmd->se_tfo->get_task_tag(cmd));
2672 
2673 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2674 
2675 	return true;
2676 }
2677 EXPORT_SYMBOL(transport_wait_for_tasks);
2678 
2679 static int transport_get_sense_codes(
2680 	struct se_cmd *cmd,
2681 	u8 *asc,
2682 	u8 *ascq)
2683 {
2684 	*asc = cmd->scsi_asc;
2685 	*ascq = cmd->scsi_ascq;
2686 
2687 	return 0;
2688 }
2689 
2690 static
2691 void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
2692 {
2693 	/* Place failed LBA in sense data information descriptor 0. */
2694 	buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
2695 	buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
2696 	buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
2697 	buffer[SPC_VALIDITY_OFFSET] = 0x80;
2698 
2699 	/* Descriptor Information: failing sector */
2700 	put_unaligned_be64(bad_sector, &buffer[12]);
2701 }
2702 
2703 int
2704 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2705 		sense_reason_t reason, int from_transport)
2706 {
2707 	unsigned char *buffer = cmd->sense_buffer;
2708 	unsigned long flags;
2709 	u8 asc = 0, ascq = 0;
2710 
2711 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2712 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2713 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2714 		return 0;
2715 	}
2716 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2717 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2718 
2719 	if (!reason && from_transport)
2720 		goto after_reason;
2721 
2722 	if (!from_transport)
2723 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2724 
2725 	/*
2726 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2727 	 * SENSE KEY values from include/scsi/scsi.h
2728 	 */
2729 	switch (reason) {
2730 	case TCM_NO_SENSE:
2731 		/* CURRENT ERROR */
2732 		buffer[0] = 0x70;
2733 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2734 		/* Not Ready */
2735 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2736 		/* NO ADDITIONAL SENSE INFORMATION */
2737 		buffer[SPC_ASC_KEY_OFFSET] = 0;
2738 		buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2739 		break;
2740 	case TCM_NON_EXISTENT_LUN:
2741 		/* CURRENT ERROR */
2742 		buffer[0] = 0x70;
2743 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2744 		/* ILLEGAL REQUEST */
2745 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2746 		/* LOGICAL UNIT NOT SUPPORTED */
2747 		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2748 		break;
2749 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2750 	case TCM_SECTOR_COUNT_TOO_MANY:
2751 		/* CURRENT ERROR */
2752 		buffer[0] = 0x70;
2753 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2754 		/* ILLEGAL REQUEST */
2755 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2756 		/* INVALID COMMAND OPERATION CODE */
2757 		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2758 		break;
2759 	case TCM_UNKNOWN_MODE_PAGE:
2760 		/* CURRENT ERROR */
2761 		buffer[0] = 0x70;
2762 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2763 		/* ILLEGAL REQUEST */
2764 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2765 		/* INVALID FIELD IN CDB */
2766 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2767 		break;
2768 	case TCM_CHECK_CONDITION_ABORT_CMD:
2769 		/* CURRENT ERROR */
2770 		buffer[0] = 0x70;
2771 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2772 		/* ABORTED COMMAND */
2773 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2774 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2775 		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2776 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2777 		break;
2778 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2779 		/* CURRENT ERROR */
2780 		buffer[0] = 0x70;
2781 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2782 		/* ABORTED COMMAND */
2783 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2784 		/* WRITE ERROR */
2785 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2786 		/* NOT ENOUGH UNSOLICITED DATA */
2787 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2788 		break;
2789 	case TCM_INVALID_CDB_FIELD:
2790 		/* CURRENT ERROR */
2791 		buffer[0] = 0x70;
2792 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2793 		/* ILLEGAL REQUEST */
2794 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2795 		/* INVALID FIELD IN CDB */
2796 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2797 		break;
2798 	case TCM_INVALID_PARAMETER_LIST:
2799 		/* CURRENT ERROR */
2800 		buffer[0] = 0x70;
2801 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2802 		/* ILLEGAL REQUEST */
2803 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2804 		/* INVALID FIELD IN PARAMETER LIST */
2805 		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2806 		break;
2807 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2808 		/* CURRENT ERROR */
2809 		buffer[0] = 0x70;
2810 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2811 		/* ILLEGAL REQUEST */
2812 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2813 		/* PARAMETER LIST LENGTH ERROR */
2814 		buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2815 		break;
2816 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2817 		/* CURRENT ERROR */
2818 		buffer[0] = 0x70;
2819 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2820 		/* ABORTED COMMAND */
2821 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2822 		/* WRITE ERROR */
2823 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2824 		/* UNEXPECTED_UNSOLICITED_DATA */
2825 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2826 		break;
2827 	case TCM_SERVICE_CRC_ERROR:
2828 		/* CURRENT ERROR */
2829 		buffer[0] = 0x70;
2830 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2831 		/* ABORTED COMMAND */
2832 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2833 		/* PROTOCOL SERVICE CRC ERROR */
2834 		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2835 		/* N/A */
2836 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2837 		break;
2838 	case TCM_SNACK_REJECTED:
2839 		/* CURRENT ERROR */
2840 		buffer[0] = 0x70;
2841 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2842 		/* ABORTED COMMAND */
2843 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2844 		/* READ ERROR */
2845 		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2846 		/* FAILED RETRANSMISSION REQUEST */
2847 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2848 		break;
2849 	case TCM_WRITE_PROTECTED:
2850 		/* CURRENT ERROR */
2851 		buffer[0] = 0x70;
2852 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2853 		/* DATA PROTECT */
2854 		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2855 		/* WRITE PROTECTED */
2856 		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2857 		break;
2858 	case TCM_ADDRESS_OUT_OF_RANGE:
2859 		/* CURRENT ERROR */
2860 		buffer[0] = 0x70;
2861 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2862 		/* ILLEGAL REQUEST */
2863 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2864 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2865 		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2866 		break;
2867 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2868 		/* CURRENT ERROR */
2869 		buffer[0] = 0x70;
2870 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2871 		/* UNIT ATTENTION */
2872 		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2873 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2874 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2875 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2876 		break;
2877 	case TCM_CHECK_CONDITION_NOT_READY:
2878 		/* CURRENT ERROR */
2879 		buffer[0] = 0x70;
2880 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2881 		/* Not Ready */
2882 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2883 		transport_get_sense_codes(cmd, &asc, &ascq);
2884 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2885 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2886 		break;
2887 	case TCM_MISCOMPARE_VERIFY:
2888 		/* CURRENT ERROR */
2889 		buffer[0] = 0x70;
2890 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2891 		buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2892 		/* MISCOMPARE DURING VERIFY OPERATION */
2893 		buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2894 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2895 		break;
2896 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2897 		/* CURRENT ERROR */
2898 		buffer[0] = 0x70;
2899 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2900 		/* ILLEGAL REQUEST */
2901 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2902 		/* LOGICAL BLOCK GUARD CHECK FAILED */
2903 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2904 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
2905 		transport_err_sector_info(buffer, cmd->bad_sector);
2906 		break;
2907 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2908 		/* CURRENT ERROR */
2909 		buffer[0] = 0x70;
2910 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2911 		/* ILLEGAL REQUEST */
2912 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2913 		/* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2914 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2915 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
2916 		transport_err_sector_info(buffer, cmd->bad_sector);
2917 		break;
2918 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2919 		/* CURRENT ERROR */
2920 		buffer[0] = 0x70;
2921 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2922 		/* ILLEGAL REQUEST */
2923 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2924 		/* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2925 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2926 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2927 		transport_err_sector_info(buffer, cmd->bad_sector);
2928 		break;
2929 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2930 	default:
2931 		/* CURRENT ERROR */
2932 		buffer[0] = 0x70;
2933 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2934 		/*
2935 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2936 		 * Solaris initiators.  Returning NOT READY instead means the
2937 		 * operations will be retried a finite number of times and we
2938 		 * can survive intermittent errors.
2939 		 */
2940 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2941 		/* LOGICAL UNIT COMMUNICATION FAILURE */
2942 		buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2943 		break;
2944 	}
2945 	/*
2946 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
2947 	 */
2948 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2949 	/*
2950 	 * Automatically padded, this value is encoded in the fabric's
2951 	 * data_length response PDU containing the SCSI defined sense data.
2952 	 */
2953 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2954 
2955 after_reason:
2956 	trace_target_cmd_complete(cmd);
2957 	return cmd->se_tfo->queue_status(cmd);
2958 }
2959 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2960 
2961 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2962 {
2963 	if (!(cmd->transport_state & CMD_T_ABORTED))
2964 		return 0;
2965 
2966 	/*
2967 	 * If cmd has been aborted but either no status is to be sent or it has
2968 	 * already been sent, just return
2969 	 */
2970 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
2971 		return 1;
2972 
2973 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2974 		 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2975 
2976 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2977 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2978 	trace_target_cmd_complete(cmd);
2979 	cmd->se_tfo->queue_status(cmd);
2980 
2981 	return 1;
2982 }
2983 EXPORT_SYMBOL(transport_check_aborted_status);
2984 
2985 void transport_send_task_abort(struct se_cmd *cmd)
2986 {
2987 	unsigned long flags;
2988 
2989 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2990 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
2991 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2992 		return;
2993 	}
2994 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2995 
2996 	/*
2997 	 * If there are still expected incoming fabric WRITEs, we wait
2998 	 * until until they have completed before sending a TASK_ABORTED
2999 	 * response.  This response with TASK_ABORTED status will be
3000 	 * queued back to fabric module by transport_check_aborted_status().
3001 	 */
3002 	if (cmd->data_direction == DMA_TO_DEVICE) {
3003 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3004 			cmd->transport_state |= CMD_T_ABORTED;
3005 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3006 			return;
3007 		}
3008 	}
3009 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3010 
3011 	transport_lun_remove_cmd(cmd);
3012 
3013 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
3014 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
3015 		cmd->se_tfo->get_task_tag(cmd));
3016 
3017 	trace_target_cmd_complete(cmd);
3018 	cmd->se_tfo->queue_status(cmd);
3019 }
3020 
3021 static void target_tmr_work(struct work_struct *work)
3022 {
3023 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3024 	struct se_device *dev = cmd->se_dev;
3025 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3026 	int ret;
3027 
3028 	switch (tmr->function) {
3029 	case TMR_ABORT_TASK:
3030 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3031 		break;
3032 	case TMR_ABORT_TASK_SET:
3033 	case TMR_CLEAR_ACA:
3034 	case TMR_CLEAR_TASK_SET:
3035 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3036 		break;
3037 	case TMR_LUN_RESET:
3038 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3039 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3040 					 TMR_FUNCTION_REJECTED;
3041 		break;
3042 	case TMR_TARGET_WARM_RESET:
3043 		tmr->response = TMR_FUNCTION_REJECTED;
3044 		break;
3045 	case TMR_TARGET_COLD_RESET:
3046 		tmr->response = TMR_FUNCTION_REJECTED;
3047 		break;
3048 	default:
3049 		pr_err("Uknown TMR function: 0x%02x.\n",
3050 				tmr->function);
3051 		tmr->response = TMR_FUNCTION_REJECTED;
3052 		break;
3053 	}
3054 
3055 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3056 	cmd->se_tfo->queue_tm_rsp(cmd);
3057 
3058 	transport_cmd_check_stop_to_fabric(cmd);
3059 }
3060 
3061 int transport_generic_handle_tmr(
3062 	struct se_cmd *cmd)
3063 {
3064 	unsigned long flags;
3065 
3066 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3067 	cmd->transport_state |= CMD_T_ACTIVE;
3068 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3069 
3070 	INIT_WORK(&cmd->work, target_tmr_work);
3071 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3072 	return 0;
3073 }
3074 EXPORT_SYMBOL(transport_generic_handle_tmr);
3075