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.h>
41 #include <scsi/scsi_cmnd.h>
42 #include <scsi/scsi_tcq.h>
43 
44 #include <target/target_core_base.h>
45 #include <target/target_core_backend.h>
46 #include <target/target_core_fabric.h>
47 #include <target/target_core_configfs.h>
48 
49 #include "target_core_internal.h"
50 #include "target_core_alua.h"
51 #include "target_core_pr.h"
52 #include "target_core_ua.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/target.h>
56 
57 static struct workqueue_struct *target_completion_wq;
58 static struct kmem_cache *se_sess_cache;
59 struct kmem_cache *se_ua_cache;
60 struct kmem_cache *t10_pr_reg_cache;
61 struct kmem_cache *t10_alua_lu_gp_cache;
62 struct kmem_cache *t10_alua_lu_gp_mem_cache;
63 struct kmem_cache *t10_alua_tg_pt_gp_cache;
64 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
65 struct kmem_cache *t10_alua_lba_map_cache;
66 struct kmem_cache *t10_alua_lba_map_mem_cache;
67 
68 static void transport_complete_task_attr(struct se_cmd *cmd);
69 static void transport_handle_queue_full(struct se_cmd *cmd,
70 		struct se_device *dev);
71 static int transport_put_cmd(struct se_cmd *cmd);
72 static void target_complete_ok_work(struct work_struct *work);
73 
74 int init_se_kmem_caches(void)
75 {
76 	se_sess_cache = kmem_cache_create("se_sess_cache",
77 			sizeof(struct se_session), __alignof__(struct se_session),
78 			0, NULL);
79 	if (!se_sess_cache) {
80 		pr_err("kmem_cache_create() for struct se_session"
81 				" failed\n");
82 		goto out;
83 	}
84 	se_ua_cache = kmem_cache_create("se_ua_cache",
85 			sizeof(struct se_ua), __alignof__(struct se_ua),
86 			0, NULL);
87 	if (!se_ua_cache) {
88 		pr_err("kmem_cache_create() for struct se_ua failed\n");
89 		goto out_free_sess_cache;
90 	}
91 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
92 			sizeof(struct t10_pr_registration),
93 			__alignof__(struct t10_pr_registration), 0, NULL);
94 	if (!t10_pr_reg_cache) {
95 		pr_err("kmem_cache_create() for struct t10_pr_registration"
96 				" failed\n");
97 		goto out_free_ua_cache;
98 	}
99 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
100 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
101 			0, NULL);
102 	if (!t10_alua_lu_gp_cache) {
103 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
104 				" failed\n");
105 		goto out_free_pr_reg_cache;
106 	}
107 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
108 			sizeof(struct t10_alua_lu_gp_member),
109 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
110 	if (!t10_alua_lu_gp_mem_cache) {
111 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
112 				"cache failed\n");
113 		goto out_free_lu_gp_cache;
114 	}
115 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
116 			sizeof(struct t10_alua_tg_pt_gp),
117 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
118 	if (!t10_alua_tg_pt_gp_cache) {
119 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
120 				"cache failed\n");
121 		goto out_free_lu_gp_mem_cache;
122 	}
123 	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
124 			"t10_alua_tg_pt_gp_mem_cache",
125 			sizeof(struct t10_alua_tg_pt_gp_member),
126 			__alignof__(struct t10_alua_tg_pt_gp_member),
127 			0, NULL);
128 	if (!t10_alua_tg_pt_gp_mem_cache) {
129 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
130 				"mem_t failed\n");
131 		goto out_free_tg_pt_gp_cache;
132 	}
133 	t10_alua_lba_map_cache = kmem_cache_create(
134 			"t10_alua_lba_map_cache",
135 			sizeof(struct t10_alua_lba_map),
136 			__alignof__(struct t10_alua_lba_map), 0, NULL);
137 	if (!t10_alua_lba_map_cache) {
138 		pr_err("kmem_cache_create() for t10_alua_lba_map_"
139 				"cache failed\n");
140 		goto out_free_tg_pt_gp_mem_cache;
141 	}
142 	t10_alua_lba_map_mem_cache = kmem_cache_create(
143 			"t10_alua_lba_map_mem_cache",
144 			sizeof(struct t10_alua_lba_map_member),
145 			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
146 	if (!t10_alua_lba_map_mem_cache) {
147 		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
148 				"cache failed\n");
149 		goto out_free_lba_map_cache;
150 	}
151 
152 	target_completion_wq = alloc_workqueue("target_completion",
153 					       WQ_MEM_RECLAIM, 0);
154 	if (!target_completion_wq)
155 		goto out_free_lba_map_mem_cache;
156 
157 	return 0;
158 
159 out_free_lba_map_mem_cache:
160 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
161 out_free_lba_map_cache:
162 	kmem_cache_destroy(t10_alua_lba_map_cache);
163 out_free_tg_pt_gp_mem_cache:
164 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
165 out_free_tg_pt_gp_cache:
166 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
167 out_free_lu_gp_mem_cache:
168 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
169 out_free_lu_gp_cache:
170 	kmem_cache_destroy(t10_alua_lu_gp_cache);
171 out_free_pr_reg_cache:
172 	kmem_cache_destroy(t10_pr_reg_cache);
173 out_free_ua_cache:
174 	kmem_cache_destroy(se_ua_cache);
175 out_free_sess_cache:
176 	kmem_cache_destroy(se_sess_cache);
177 out:
178 	return -ENOMEM;
179 }
180 
181 void release_se_kmem_caches(void)
182 {
183 	destroy_workqueue(target_completion_wq);
184 	kmem_cache_destroy(se_sess_cache);
185 	kmem_cache_destroy(se_ua_cache);
186 	kmem_cache_destroy(t10_pr_reg_cache);
187 	kmem_cache_destroy(t10_alua_lu_gp_cache);
188 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
189 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
190 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
191 	kmem_cache_destroy(t10_alua_lba_map_cache);
192 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
193 }
194 
195 /* This code ensures unique mib indexes are handed out. */
196 static DEFINE_SPINLOCK(scsi_mib_index_lock);
197 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
198 
199 /*
200  * Allocate a new row index for the entry type specified
201  */
202 u32 scsi_get_new_index(scsi_index_t type)
203 {
204 	u32 new_index;
205 
206 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
207 
208 	spin_lock(&scsi_mib_index_lock);
209 	new_index = ++scsi_mib_index[type];
210 	spin_unlock(&scsi_mib_index_lock);
211 
212 	return new_index;
213 }
214 
215 void transport_subsystem_check_init(void)
216 {
217 	int ret;
218 	static int sub_api_initialized;
219 
220 	if (sub_api_initialized)
221 		return;
222 
223 	ret = request_module("target_core_iblock");
224 	if (ret != 0)
225 		pr_err("Unable to load target_core_iblock\n");
226 
227 	ret = request_module("target_core_file");
228 	if (ret != 0)
229 		pr_err("Unable to load target_core_file\n");
230 
231 	ret = request_module("target_core_pscsi");
232 	if (ret != 0)
233 		pr_err("Unable to load target_core_pscsi\n");
234 
235 	ret = request_module("target_core_user");
236 	if (ret != 0)
237 		pr_err("Unable to load target_core_user\n");
238 
239 	sub_api_initialized = 1;
240 }
241 
242 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
243 {
244 	struct se_session *se_sess;
245 
246 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
247 	if (!se_sess) {
248 		pr_err("Unable to allocate struct se_session from"
249 				" se_sess_cache\n");
250 		return ERR_PTR(-ENOMEM);
251 	}
252 	INIT_LIST_HEAD(&se_sess->sess_list);
253 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
254 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
255 	INIT_LIST_HEAD(&se_sess->sess_wait_list);
256 	spin_lock_init(&se_sess->sess_cmd_lock);
257 	kref_init(&se_sess->sess_kref);
258 	se_sess->sup_prot_ops = sup_prot_ops;
259 
260 	return se_sess;
261 }
262 EXPORT_SYMBOL(transport_init_session);
263 
264 int transport_alloc_session_tags(struct se_session *se_sess,
265 			         unsigned int tag_num, unsigned int tag_size)
266 {
267 	int rc;
268 
269 	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
270 					GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
271 	if (!se_sess->sess_cmd_map) {
272 		se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
273 		if (!se_sess->sess_cmd_map) {
274 			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
275 			return -ENOMEM;
276 		}
277 	}
278 
279 	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
280 	if (rc < 0) {
281 		pr_err("Unable to init se_sess->sess_tag_pool,"
282 			" tag_num: %u\n", tag_num);
283 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
284 			vfree(se_sess->sess_cmd_map);
285 		else
286 			kfree(se_sess->sess_cmd_map);
287 		se_sess->sess_cmd_map = NULL;
288 		return -ENOMEM;
289 	}
290 
291 	return 0;
292 }
293 EXPORT_SYMBOL(transport_alloc_session_tags);
294 
295 struct se_session *transport_init_session_tags(unsigned int tag_num,
296 					       unsigned int tag_size,
297 					       enum target_prot_op sup_prot_ops)
298 {
299 	struct se_session *se_sess;
300 	int rc;
301 
302 	se_sess = transport_init_session(sup_prot_ops);
303 	if (IS_ERR(se_sess))
304 		return se_sess;
305 
306 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
307 	if (rc < 0) {
308 		transport_free_session(se_sess);
309 		return ERR_PTR(-ENOMEM);
310 	}
311 
312 	return se_sess;
313 }
314 EXPORT_SYMBOL(transport_init_session_tags);
315 
316 /*
317  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
318  */
319 void __transport_register_session(
320 	struct se_portal_group *se_tpg,
321 	struct se_node_acl *se_nacl,
322 	struct se_session *se_sess,
323 	void *fabric_sess_ptr)
324 {
325 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
326 	unsigned char buf[PR_REG_ISID_LEN];
327 
328 	se_sess->se_tpg = se_tpg;
329 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
330 	/*
331 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
332 	 *
333 	 * Only set for struct se_session's that will actually be moving I/O.
334 	 * eg: *NOT* discovery sessions.
335 	 */
336 	if (se_nacl) {
337 		/*
338 		 *
339 		 * Determine if fabric allows for T10-PI feature bits exposed to
340 		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
341 		 *
342 		 * If so, then always save prot_type on a per se_node_acl node
343 		 * basis and re-instate the previous sess_prot_type to avoid
344 		 * disabling PI from below any previously initiator side
345 		 * registered LUNs.
346 		 */
347 		if (se_nacl->saved_prot_type)
348 			se_sess->sess_prot_type = se_nacl->saved_prot_type;
349 		else if (tfo->tpg_check_prot_fabric_only)
350 			se_sess->sess_prot_type = se_nacl->saved_prot_type =
351 					tfo->tpg_check_prot_fabric_only(se_tpg);
352 		/*
353 		 * If the fabric module supports an ISID based TransportID,
354 		 * save this value in binary from the fabric I_T Nexus now.
355 		 */
356 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
357 			memset(&buf[0], 0, PR_REG_ISID_LEN);
358 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
359 					&buf[0], PR_REG_ISID_LEN);
360 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
361 		}
362 		kref_get(&se_nacl->acl_kref);
363 
364 		spin_lock_irq(&se_nacl->nacl_sess_lock);
365 		/*
366 		 * The se_nacl->nacl_sess pointer will be set to the
367 		 * last active I_T Nexus for each struct se_node_acl.
368 		 */
369 		se_nacl->nacl_sess = se_sess;
370 
371 		list_add_tail(&se_sess->sess_acl_list,
372 			      &se_nacl->acl_sess_list);
373 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
374 	}
375 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
376 
377 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
378 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
379 }
380 EXPORT_SYMBOL(__transport_register_session);
381 
382 void transport_register_session(
383 	struct se_portal_group *se_tpg,
384 	struct se_node_acl *se_nacl,
385 	struct se_session *se_sess,
386 	void *fabric_sess_ptr)
387 {
388 	unsigned long flags;
389 
390 	spin_lock_irqsave(&se_tpg->session_lock, flags);
391 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
392 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
393 }
394 EXPORT_SYMBOL(transport_register_session);
395 
396 static void target_release_session(struct kref *kref)
397 {
398 	struct se_session *se_sess = container_of(kref,
399 			struct se_session, sess_kref);
400 	struct se_portal_group *se_tpg = se_sess->se_tpg;
401 
402 	se_tpg->se_tpg_tfo->close_session(se_sess);
403 }
404 
405 void target_get_session(struct se_session *se_sess)
406 {
407 	kref_get(&se_sess->sess_kref);
408 }
409 EXPORT_SYMBOL(target_get_session);
410 
411 void target_put_session(struct se_session *se_sess)
412 {
413 	struct se_portal_group *tpg = se_sess->se_tpg;
414 
415 	if (tpg->se_tpg_tfo->put_session != NULL) {
416 		tpg->se_tpg_tfo->put_session(se_sess);
417 		return;
418 	}
419 	kref_put(&se_sess->sess_kref, target_release_session);
420 }
421 EXPORT_SYMBOL(target_put_session);
422 
423 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
424 {
425 	struct se_session *se_sess;
426 	ssize_t len = 0;
427 
428 	spin_lock_bh(&se_tpg->session_lock);
429 	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
430 		if (!se_sess->se_node_acl)
431 			continue;
432 		if (!se_sess->se_node_acl->dynamic_node_acl)
433 			continue;
434 		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
435 			break;
436 
437 		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
438 				se_sess->se_node_acl->initiatorname);
439 		len += 1; /* Include NULL terminator */
440 	}
441 	spin_unlock_bh(&se_tpg->session_lock);
442 
443 	return len;
444 }
445 EXPORT_SYMBOL(target_show_dynamic_sessions);
446 
447 static void target_complete_nacl(struct kref *kref)
448 {
449 	struct se_node_acl *nacl = container_of(kref,
450 				struct se_node_acl, acl_kref);
451 
452 	complete(&nacl->acl_free_comp);
453 }
454 
455 void target_put_nacl(struct se_node_acl *nacl)
456 {
457 	kref_put(&nacl->acl_kref, target_complete_nacl);
458 }
459 
460 void transport_deregister_session_configfs(struct se_session *se_sess)
461 {
462 	struct se_node_acl *se_nacl;
463 	unsigned long flags;
464 	/*
465 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
466 	 */
467 	se_nacl = se_sess->se_node_acl;
468 	if (se_nacl) {
469 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
470 		if (se_nacl->acl_stop == 0)
471 			list_del(&se_sess->sess_acl_list);
472 		/*
473 		 * If the session list is empty, then clear the pointer.
474 		 * Otherwise, set the struct se_session pointer from the tail
475 		 * element of the per struct se_node_acl active session list.
476 		 */
477 		if (list_empty(&se_nacl->acl_sess_list))
478 			se_nacl->nacl_sess = NULL;
479 		else {
480 			se_nacl->nacl_sess = container_of(
481 					se_nacl->acl_sess_list.prev,
482 					struct se_session, sess_acl_list);
483 		}
484 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
485 	}
486 }
487 EXPORT_SYMBOL(transport_deregister_session_configfs);
488 
489 void transport_free_session(struct se_session *se_sess)
490 {
491 	if (se_sess->sess_cmd_map) {
492 		percpu_ida_destroy(&se_sess->sess_tag_pool);
493 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
494 			vfree(se_sess->sess_cmd_map);
495 		else
496 			kfree(se_sess->sess_cmd_map);
497 	}
498 	kmem_cache_free(se_sess_cache, se_sess);
499 }
500 EXPORT_SYMBOL(transport_free_session);
501 
502 void transport_deregister_session(struct se_session *se_sess)
503 {
504 	struct se_portal_group *se_tpg = se_sess->se_tpg;
505 	const struct target_core_fabric_ops *se_tfo;
506 	struct se_node_acl *se_nacl;
507 	unsigned long flags;
508 	bool comp_nacl = true;
509 
510 	if (!se_tpg) {
511 		transport_free_session(se_sess);
512 		return;
513 	}
514 	se_tfo = se_tpg->se_tpg_tfo;
515 
516 	spin_lock_irqsave(&se_tpg->session_lock, flags);
517 	list_del(&se_sess->sess_list);
518 	se_sess->se_tpg = NULL;
519 	se_sess->fabric_sess_ptr = NULL;
520 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
521 
522 	/*
523 	 * Determine if we need to do extra work for this initiator node's
524 	 * struct se_node_acl if it had been previously dynamically generated.
525 	 */
526 	se_nacl = se_sess->se_node_acl;
527 
528 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
529 	if (se_nacl && se_nacl->dynamic_node_acl) {
530 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
531 			list_del(&se_nacl->acl_list);
532 			se_tpg->num_node_acls--;
533 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
534 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
535 			core_free_device_list_for_node(se_nacl, se_tpg);
536 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
537 
538 			comp_nacl = false;
539 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
540 		}
541 	}
542 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
543 
544 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
545 		se_tpg->se_tpg_tfo->get_fabric_name());
546 	/*
547 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
548 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
549 	 * removal context.
550 	 */
551 	if (se_nacl && comp_nacl)
552 		target_put_nacl(se_nacl);
553 
554 	transport_free_session(se_sess);
555 }
556 EXPORT_SYMBOL(transport_deregister_session);
557 
558 /*
559  * Called with cmd->t_state_lock held.
560  */
561 static void target_remove_from_state_list(struct se_cmd *cmd)
562 {
563 	struct se_device *dev = cmd->se_dev;
564 	unsigned long flags;
565 
566 	if (!dev)
567 		return;
568 
569 	if (cmd->transport_state & CMD_T_BUSY)
570 		return;
571 
572 	spin_lock_irqsave(&dev->execute_task_lock, flags);
573 	if (cmd->state_active) {
574 		list_del(&cmd->state_list);
575 		cmd->state_active = false;
576 	}
577 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
578 }
579 
580 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
581 				    bool write_pending)
582 {
583 	unsigned long flags;
584 
585 	spin_lock_irqsave(&cmd->t_state_lock, flags);
586 	if (write_pending)
587 		cmd->t_state = TRANSPORT_WRITE_PENDING;
588 
589 	if (remove_from_lists) {
590 		target_remove_from_state_list(cmd);
591 
592 		/*
593 		 * Clear struct se_cmd->se_lun before the handoff to FE.
594 		 */
595 		cmd->se_lun = NULL;
596 	}
597 
598 	/*
599 	 * Determine if frontend context caller is requesting the stopping of
600 	 * this command for frontend exceptions.
601 	 */
602 	if (cmd->transport_state & CMD_T_STOP) {
603 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
604 			__func__, __LINE__,
605 			cmd->se_tfo->get_task_tag(cmd));
606 
607 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
608 
609 		complete_all(&cmd->t_transport_stop_comp);
610 		return 1;
611 	}
612 
613 	cmd->transport_state &= ~CMD_T_ACTIVE;
614 	if (remove_from_lists) {
615 		/*
616 		 * Some fabric modules like tcm_loop can release
617 		 * their internally allocated I/O reference now and
618 		 * struct se_cmd now.
619 		 *
620 		 * Fabric modules are expected to return '1' here if the
621 		 * se_cmd being passed is released at this point,
622 		 * or zero if not being released.
623 		 */
624 		if (cmd->se_tfo->check_stop_free != NULL) {
625 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
626 			return cmd->se_tfo->check_stop_free(cmd);
627 		}
628 	}
629 
630 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
631 	return 0;
632 }
633 
634 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
635 {
636 	return transport_cmd_check_stop(cmd, true, false);
637 }
638 
639 static void transport_lun_remove_cmd(struct se_cmd *cmd)
640 {
641 	struct se_lun *lun = cmd->se_lun;
642 
643 	if (!lun)
644 		return;
645 
646 	if (cmpxchg(&cmd->lun_ref_active, true, false))
647 		percpu_ref_put(&lun->lun_ref);
648 }
649 
650 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
651 {
652 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
653 		transport_lun_remove_cmd(cmd);
654 	/*
655 	 * Allow the fabric driver to unmap any resources before
656 	 * releasing the descriptor via TFO->release_cmd()
657 	 */
658 	if (remove)
659 		cmd->se_tfo->aborted_task(cmd);
660 
661 	if (transport_cmd_check_stop_to_fabric(cmd))
662 		return;
663 	if (remove)
664 		transport_put_cmd(cmd);
665 }
666 
667 static void target_complete_failure_work(struct work_struct *work)
668 {
669 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
670 
671 	transport_generic_request_failure(cmd,
672 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
673 }
674 
675 /*
676  * Used when asking transport to copy Sense Data from the underlying
677  * Linux/SCSI struct scsi_cmnd
678  */
679 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
680 {
681 	struct se_device *dev = cmd->se_dev;
682 
683 	WARN_ON(!cmd->se_lun);
684 
685 	if (!dev)
686 		return NULL;
687 
688 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
689 		return NULL;
690 
691 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
692 
693 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
694 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
695 	return cmd->sense_buffer;
696 }
697 
698 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
699 {
700 	struct se_device *dev = cmd->se_dev;
701 	int success = scsi_status == GOOD;
702 	unsigned long flags;
703 
704 	cmd->scsi_status = scsi_status;
705 
706 
707 	spin_lock_irqsave(&cmd->t_state_lock, flags);
708 	cmd->transport_state &= ~CMD_T_BUSY;
709 
710 	if (dev && dev->transport->transport_complete) {
711 		dev->transport->transport_complete(cmd,
712 				cmd->t_data_sg,
713 				transport_get_sense_buffer(cmd));
714 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
715 			success = 1;
716 	}
717 
718 	/*
719 	 * See if we are waiting to complete for an exception condition.
720 	 */
721 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
722 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
723 		complete(&cmd->task_stop_comp);
724 		return;
725 	}
726 
727 	/*
728 	 * Check for case where an explicit ABORT_TASK has been received
729 	 * and transport_wait_for_tasks() will be waiting for completion..
730 	 */
731 	if (cmd->transport_state & CMD_T_ABORTED &&
732 	    cmd->transport_state & CMD_T_STOP) {
733 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
734 		complete_all(&cmd->t_transport_stop_comp);
735 		return;
736 	} else if (!success) {
737 		INIT_WORK(&cmd->work, target_complete_failure_work);
738 	} else {
739 		INIT_WORK(&cmd->work, target_complete_ok_work);
740 	}
741 
742 	cmd->t_state = TRANSPORT_COMPLETE;
743 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
744 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
745 
746 	queue_work(target_completion_wq, &cmd->work);
747 }
748 EXPORT_SYMBOL(target_complete_cmd);
749 
750 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
751 {
752 	if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
753 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
754 			cmd->residual_count += cmd->data_length - length;
755 		} else {
756 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
757 			cmd->residual_count = cmd->data_length - length;
758 		}
759 
760 		cmd->data_length = length;
761 	}
762 
763 	target_complete_cmd(cmd, scsi_status);
764 }
765 EXPORT_SYMBOL(target_complete_cmd_with_length);
766 
767 static void target_add_to_state_list(struct se_cmd *cmd)
768 {
769 	struct se_device *dev = cmd->se_dev;
770 	unsigned long flags;
771 
772 	spin_lock_irqsave(&dev->execute_task_lock, flags);
773 	if (!cmd->state_active) {
774 		list_add_tail(&cmd->state_list, &dev->state_list);
775 		cmd->state_active = true;
776 	}
777 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
778 }
779 
780 /*
781  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
782  */
783 static void transport_write_pending_qf(struct se_cmd *cmd);
784 static void transport_complete_qf(struct se_cmd *cmd);
785 
786 void target_qf_do_work(struct work_struct *work)
787 {
788 	struct se_device *dev = container_of(work, struct se_device,
789 					qf_work_queue);
790 	LIST_HEAD(qf_cmd_list);
791 	struct se_cmd *cmd, *cmd_tmp;
792 
793 	spin_lock_irq(&dev->qf_cmd_lock);
794 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
795 	spin_unlock_irq(&dev->qf_cmd_lock);
796 
797 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
798 		list_del(&cmd->se_qf_node);
799 		atomic_dec_mb(&dev->dev_qf_count);
800 
801 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
802 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
803 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
804 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
805 			: "UNKNOWN");
806 
807 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
808 			transport_write_pending_qf(cmd);
809 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
810 			transport_complete_qf(cmd);
811 	}
812 }
813 
814 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
815 {
816 	switch (cmd->data_direction) {
817 	case DMA_NONE:
818 		return "NONE";
819 	case DMA_FROM_DEVICE:
820 		return "READ";
821 	case DMA_TO_DEVICE:
822 		return "WRITE";
823 	case DMA_BIDIRECTIONAL:
824 		return "BIDI";
825 	default:
826 		break;
827 	}
828 
829 	return "UNKNOWN";
830 }
831 
832 void transport_dump_dev_state(
833 	struct se_device *dev,
834 	char *b,
835 	int *bl)
836 {
837 	*bl += sprintf(b + *bl, "Status: ");
838 	if (dev->export_count)
839 		*bl += sprintf(b + *bl, "ACTIVATED");
840 	else
841 		*bl += sprintf(b + *bl, "DEACTIVATED");
842 
843 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
844 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
845 		dev->dev_attrib.block_size,
846 		dev->dev_attrib.hw_max_sectors);
847 	*bl += sprintf(b + *bl, "        ");
848 }
849 
850 void transport_dump_vpd_proto_id(
851 	struct t10_vpd *vpd,
852 	unsigned char *p_buf,
853 	int p_buf_len)
854 {
855 	unsigned char buf[VPD_TMP_BUF_SIZE];
856 	int len;
857 
858 	memset(buf, 0, VPD_TMP_BUF_SIZE);
859 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
860 
861 	switch (vpd->protocol_identifier) {
862 	case 0x00:
863 		sprintf(buf+len, "Fibre Channel\n");
864 		break;
865 	case 0x10:
866 		sprintf(buf+len, "Parallel SCSI\n");
867 		break;
868 	case 0x20:
869 		sprintf(buf+len, "SSA\n");
870 		break;
871 	case 0x30:
872 		sprintf(buf+len, "IEEE 1394\n");
873 		break;
874 	case 0x40:
875 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
876 				" Protocol\n");
877 		break;
878 	case 0x50:
879 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
880 		break;
881 	case 0x60:
882 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
883 		break;
884 	case 0x70:
885 		sprintf(buf+len, "Automation/Drive Interface Transport"
886 				" Protocol\n");
887 		break;
888 	case 0x80:
889 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
890 		break;
891 	default:
892 		sprintf(buf+len, "Unknown 0x%02x\n",
893 				vpd->protocol_identifier);
894 		break;
895 	}
896 
897 	if (p_buf)
898 		strncpy(p_buf, buf, p_buf_len);
899 	else
900 		pr_debug("%s", buf);
901 }
902 
903 void
904 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
905 {
906 	/*
907 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
908 	 *
909 	 * from spc3r23.pdf section 7.5.1
910 	 */
911 	 if (page_83[1] & 0x80) {
912 		vpd->protocol_identifier = (page_83[0] & 0xf0);
913 		vpd->protocol_identifier_set = 1;
914 		transport_dump_vpd_proto_id(vpd, NULL, 0);
915 	}
916 }
917 EXPORT_SYMBOL(transport_set_vpd_proto_id);
918 
919 int transport_dump_vpd_assoc(
920 	struct t10_vpd *vpd,
921 	unsigned char *p_buf,
922 	int p_buf_len)
923 {
924 	unsigned char buf[VPD_TMP_BUF_SIZE];
925 	int ret = 0;
926 	int len;
927 
928 	memset(buf, 0, VPD_TMP_BUF_SIZE);
929 	len = sprintf(buf, "T10 VPD Identifier Association: ");
930 
931 	switch (vpd->association) {
932 	case 0x00:
933 		sprintf(buf+len, "addressed logical unit\n");
934 		break;
935 	case 0x10:
936 		sprintf(buf+len, "target port\n");
937 		break;
938 	case 0x20:
939 		sprintf(buf+len, "SCSI target device\n");
940 		break;
941 	default:
942 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
943 		ret = -EINVAL;
944 		break;
945 	}
946 
947 	if (p_buf)
948 		strncpy(p_buf, buf, p_buf_len);
949 	else
950 		pr_debug("%s", buf);
951 
952 	return ret;
953 }
954 
955 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
956 {
957 	/*
958 	 * The VPD identification association..
959 	 *
960 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
961 	 */
962 	vpd->association = (page_83[1] & 0x30);
963 	return transport_dump_vpd_assoc(vpd, NULL, 0);
964 }
965 EXPORT_SYMBOL(transport_set_vpd_assoc);
966 
967 int transport_dump_vpd_ident_type(
968 	struct t10_vpd *vpd,
969 	unsigned char *p_buf,
970 	int p_buf_len)
971 {
972 	unsigned char buf[VPD_TMP_BUF_SIZE];
973 	int ret = 0;
974 	int len;
975 
976 	memset(buf, 0, VPD_TMP_BUF_SIZE);
977 	len = sprintf(buf, "T10 VPD Identifier Type: ");
978 
979 	switch (vpd->device_identifier_type) {
980 	case 0x00:
981 		sprintf(buf+len, "Vendor specific\n");
982 		break;
983 	case 0x01:
984 		sprintf(buf+len, "T10 Vendor ID based\n");
985 		break;
986 	case 0x02:
987 		sprintf(buf+len, "EUI-64 based\n");
988 		break;
989 	case 0x03:
990 		sprintf(buf+len, "NAA\n");
991 		break;
992 	case 0x04:
993 		sprintf(buf+len, "Relative target port identifier\n");
994 		break;
995 	case 0x08:
996 		sprintf(buf+len, "SCSI name string\n");
997 		break;
998 	default:
999 		sprintf(buf+len, "Unsupported: 0x%02x\n",
1000 				vpd->device_identifier_type);
1001 		ret = -EINVAL;
1002 		break;
1003 	}
1004 
1005 	if (p_buf) {
1006 		if (p_buf_len < strlen(buf)+1)
1007 			return -EINVAL;
1008 		strncpy(p_buf, buf, p_buf_len);
1009 	} else {
1010 		pr_debug("%s", buf);
1011 	}
1012 
1013 	return ret;
1014 }
1015 
1016 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1017 {
1018 	/*
1019 	 * The VPD identifier type..
1020 	 *
1021 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1022 	 */
1023 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1024 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1025 }
1026 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1027 
1028 int transport_dump_vpd_ident(
1029 	struct t10_vpd *vpd,
1030 	unsigned char *p_buf,
1031 	int p_buf_len)
1032 {
1033 	unsigned char buf[VPD_TMP_BUF_SIZE];
1034 	int ret = 0;
1035 
1036 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1037 
1038 	switch (vpd->device_identifier_code_set) {
1039 	case 0x01: /* Binary */
1040 		snprintf(buf, sizeof(buf),
1041 			"T10 VPD Binary Device Identifier: %s\n",
1042 			&vpd->device_identifier[0]);
1043 		break;
1044 	case 0x02: /* ASCII */
1045 		snprintf(buf, sizeof(buf),
1046 			"T10 VPD ASCII Device Identifier: %s\n",
1047 			&vpd->device_identifier[0]);
1048 		break;
1049 	case 0x03: /* UTF-8 */
1050 		snprintf(buf, sizeof(buf),
1051 			"T10 VPD UTF-8 Device Identifier: %s\n",
1052 			&vpd->device_identifier[0]);
1053 		break;
1054 	default:
1055 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1056 			" 0x%02x", vpd->device_identifier_code_set);
1057 		ret = -EINVAL;
1058 		break;
1059 	}
1060 
1061 	if (p_buf)
1062 		strncpy(p_buf, buf, p_buf_len);
1063 	else
1064 		pr_debug("%s", buf);
1065 
1066 	return ret;
1067 }
1068 
1069 int
1070 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1071 {
1072 	static const char hex_str[] = "0123456789abcdef";
1073 	int j = 0, i = 4; /* offset to start of the identifier */
1074 
1075 	/*
1076 	 * The VPD Code Set (encoding)
1077 	 *
1078 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1079 	 */
1080 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1081 	switch (vpd->device_identifier_code_set) {
1082 	case 0x01: /* Binary */
1083 		vpd->device_identifier[j++] =
1084 				hex_str[vpd->device_identifier_type];
1085 		while (i < (4 + page_83[3])) {
1086 			vpd->device_identifier[j++] =
1087 				hex_str[(page_83[i] & 0xf0) >> 4];
1088 			vpd->device_identifier[j++] =
1089 				hex_str[page_83[i] & 0x0f];
1090 			i++;
1091 		}
1092 		break;
1093 	case 0x02: /* ASCII */
1094 	case 0x03: /* UTF-8 */
1095 		while (i < (4 + page_83[3]))
1096 			vpd->device_identifier[j++] = page_83[i++];
1097 		break;
1098 	default:
1099 		break;
1100 	}
1101 
1102 	return transport_dump_vpd_ident(vpd, NULL, 0);
1103 }
1104 EXPORT_SYMBOL(transport_set_vpd_ident);
1105 
1106 sense_reason_t
1107 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1108 {
1109 	struct se_device *dev = cmd->se_dev;
1110 
1111 	if (cmd->unknown_data_length) {
1112 		cmd->data_length = size;
1113 	} else if (size != cmd->data_length) {
1114 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1115 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1116 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1117 				cmd->data_length, size, cmd->t_task_cdb[0]);
1118 
1119 		if (cmd->data_direction == DMA_TO_DEVICE) {
1120 			pr_err("Rejecting underflow/overflow"
1121 					" WRITE data\n");
1122 			return TCM_INVALID_CDB_FIELD;
1123 		}
1124 		/*
1125 		 * Reject READ_* or WRITE_* with overflow/underflow for
1126 		 * type SCF_SCSI_DATA_CDB.
1127 		 */
1128 		if (dev->dev_attrib.block_size != 512)  {
1129 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1130 				" CDB on non 512-byte sector setup subsystem"
1131 				" plugin: %s\n", dev->transport->name);
1132 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1133 			return TCM_INVALID_CDB_FIELD;
1134 		}
1135 		/*
1136 		 * For the overflow case keep the existing fabric provided
1137 		 * ->data_length.  Otherwise for the underflow case, reset
1138 		 * ->data_length to the smaller SCSI expected data transfer
1139 		 * length.
1140 		 */
1141 		if (size > cmd->data_length) {
1142 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1143 			cmd->residual_count = (size - cmd->data_length);
1144 		} else {
1145 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1146 			cmd->residual_count = (cmd->data_length - size);
1147 			cmd->data_length = size;
1148 		}
1149 	}
1150 
1151 	return 0;
1152 
1153 }
1154 
1155 /*
1156  * Used by fabric modules containing a local struct se_cmd within their
1157  * fabric dependent per I/O descriptor.
1158  */
1159 void transport_init_se_cmd(
1160 	struct se_cmd *cmd,
1161 	const struct target_core_fabric_ops *tfo,
1162 	struct se_session *se_sess,
1163 	u32 data_length,
1164 	int data_direction,
1165 	int task_attr,
1166 	unsigned char *sense_buffer)
1167 {
1168 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1169 	INIT_LIST_HEAD(&cmd->se_qf_node);
1170 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1171 	INIT_LIST_HEAD(&cmd->state_list);
1172 	init_completion(&cmd->t_transport_stop_comp);
1173 	init_completion(&cmd->cmd_wait_comp);
1174 	init_completion(&cmd->task_stop_comp);
1175 	spin_lock_init(&cmd->t_state_lock);
1176 	kref_init(&cmd->cmd_kref);
1177 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1178 
1179 	cmd->se_tfo = tfo;
1180 	cmd->se_sess = se_sess;
1181 	cmd->data_length = data_length;
1182 	cmd->data_direction = data_direction;
1183 	cmd->sam_task_attr = task_attr;
1184 	cmd->sense_buffer = sense_buffer;
1185 
1186 	cmd->state_active = false;
1187 }
1188 EXPORT_SYMBOL(transport_init_se_cmd);
1189 
1190 static sense_reason_t
1191 transport_check_alloc_task_attr(struct se_cmd *cmd)
1192 {
1193 	struct se_device *dev = cmd->se_dev;
1194 
1195 	/*
1196 	 * Check if SAM Task Attribute emulation is enabled for this
1197 	 * struct se_device storage object
1198 	 */
1199 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1200 		return 0;
1201 
1202 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1203 		pr_debug("SAM Task Attribute ACA"
1204 			" emulation is not supported\n");
1205 		return TCM_INVALID_CDB_FIELD;
1206 	}
1207 	/*
1208 	 * Used to determine when ORDERED commands should go from
1209 	 * Dormant to Active status.
1210 	 */
1211 	cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1212 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1213 			cmd->se_ordered_id, cmd->sam_task_attr,
1214 			dev->transport->name);
1215 	return 0;
1216 }
1217 
1218 sense_reason_t
1219 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1220 {
1221 	struct se_device *dev = cmd->se_dev;
1222 	sense_reason_t ret;
1223 
1224 	/*
1225 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1226 	 * for VARIABLE_LENGTH_CMD
1227 	 */
1228 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1229 		pr_err("Received SCSI CDB with command_size: %d that"
1230 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1231 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1232 		return TCM_INVALID_CDB_FIELD;
1233 	}
1234 	/*
1235 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1236 	 * allocate the additional extended CDB buffer now..  Otherwise
1237 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1238 	 */
1239 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1240 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1241 						GFP_KERNEL);
1242 		if (!cmd->t_task_cdb) {
1243 			pr_err("Unable to allocate cmd->t_task_cdb"
1244 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1245 				scsi_command_size(cdb),
1246 				(unsigned long)sizeof(cmd->__t_task_cdb));
1247 			return TCM_OUT_OF_RESOURCES;
1248 		}
1249 	} else
1250 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1251 	/*
1252 	 * Copy the original CDB into cmd->
1253 	 */
1254 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1255 
1256 	trace_target_sequencer_start(cmd);
1257 
1258 	/*
1259 	 * Check for an existing UNIT ATTENTION condition
1260 	 */
1261 	ret = target_scsi3_ua_check(cmd);
1262 	if (ret)
1263 		return ret;
1264 
1265 	ret = target_alua_state_check(cmd);
1266 	if (ret)
1267 		return ret;
1268 
1269 	ret = target_check_reservation(cmd);
1270 	if (ret) {
1271 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1272 		return ret;
1273 	}
1274 
1275 	ret = dev->transport->parse_cdb(cmd);
1276 	if (ret)
1277 		return ret;
1278 
1279 	ret = transport_check_alloc_task_attr(cmd);
1280 	if (ret)
1281 		return ret;
1282 
1283 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1284 
1285 	spin_lock(&cmd->se_lun->lun_sep_lock);
1286 	if (cmd->se_lun->lun_sep)
1287 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1288 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1289 	return 0;
1290 }
1291 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1292 
1293 /*
1294  * Used by fabric module frontends to queue tasks directly.
1295  * Many only be used from process context only
1296  */
1297 int transport_handle_cdb_direct(
1298 	struct se_cmd *cmd)
1299 {
1300 	sense_reason_t ret;
1301 
1302 	if (!cmd->se_lun) {
1303 		dump_stack();
1304 		pr_err("cmd->se_lun is NULL\n");
1305 		return -EINVAL;
1306 	}
1307 	if (in_interrupt()) {
1308 		dump_stack();
1309 		pr_err("transport_generic_handle_cdb cannot be called"
1310 				" from interrupt context\n");
1311 		return -EINVAL;
1312 	}
1313 	/*
1314 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1315 	 * outstanding descriptors are handled correctly during shutdown via
1316 	 * transport_wait_for_tasks()
1317 	 *
1318 	 * Also, we don't take cmd->t_state_lock here as we only expect
1319 	 * this to be called for initial descriptor submission.
1320 	 */
1321 	cmd->t_state = TRANSPORT_NEW_CMD;
1322 	cmd->transport_state |= CMD_T_ACTIVE;
1323 
1324 	/*
1325 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1326 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1327 	 * and call transport_generic_request_failure() if necessary..
1328 	 */
1329 	ret = transport_generic_new_cmd(cmd);
1330 	if (ret)
1331 		transport_generic_request_failure(cmd, ret);
1332 	return 0;
1333 }
1334 EXPORT_SYMBOL(transport_handle_cdb_direct);
1335 
1336 sense_reason_t
1337 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1338 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1339 {
1340 	if (!sgl || !sgl_count)
1341 		return 0;
1342 
1343 	/*
1344 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1345 	 * scatterlists already have been set to follow what the fabric
1346 	 * passes for the original expected data transfer length.
1347 	 */
1348 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1349 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1350 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1351 		return TCM_INVALID_CDB_FIELD;
1352 	}
1353 
1354 	cmd->t_data_sg = sgl;
1355 	cmd->t_data_nents = sgl_count;
1356 
1357 	if (sgl_bidi && sgl_bidi_count) {
1358 		cmd->t_bidi_data_sg = sgl_bidi;
1359 		cmd->t_bidi_data_nents = sgl_bidi_count;
1360 	}
1361 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1362 	return 0;
1363 }
1364 
1365 /*
1366  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1367  * 			 se_cmd + use pre-allocated SGL memory.
1368  *
1369  * @se_cmd: command descriptor to submit
1370  * @se_sess: associated se_sess for endpoint
1371  * @cdb: pointer to SCSI CDB
1372  * @sense: pointer to SCSI sense buffer
1373  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1374  * @data_length: fabric expected data transfer length
1375  * @task_addr: SAM task attribute
1376  * @data_dir: DMA data direction
1377  * @flags: flags for command submission from target_sc_flags_tables
1378  * @sgl: struct scatterlist memory for unidirectional mapping
1379  * @sgl_count: scatterlist count for unidirectional mapping
1380  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1381  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1382  * @sgl_prot: struct scatterlist memory protection information
1383  * @sgl_prot_count: scatterlist count for protection information
1384  *
1385  * Returns non zero to signal active I/O shutdown failure.  All other
1386  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1387  * but still return zero here.
1388  *
1389  * This may only be called from process context, and also currently
1390  * assumes internal allocation of fabric payload buffer by target-core.
1391  */
1392 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1393 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1394 		u32 data_length, int task_attr, int data_dir, int flags,
1395 		struct scatterlist *sgl, u32 sgl_count,
1396 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1397 		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1398 {
1399 	struct se_portal_group *se_tpg;
1400 	sense_reason_t rc;
1401 	int ret;
1402 
1403 	se_tpg = se_sess->se_tpg;
1404 	BUG_ON(!se_tpg);
1405 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1406 	BUG_ON(in_interrupt());
1407 	/*
1408 	 * Initialize se_cmd for target operation.  From this point
1409 	 * exceptions are handled by sending exception status via
1410 	 * target_core_fabric_ops->queue_status() callback
1411 	 */
1412 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1413 				data_length, data_dir, task_attr, sense);
1414 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1415 		se_cmd->unknown_data_length = 1;
1416 	/*
1417 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1418 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1419 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1420 	 * kref_put() to happen during fabric packet acknowledgement.
1421 	 */
1422 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1423 	if (ret)
1424 		return ret;
1425 	/*
1426 	 * Signal bidirectional data payloads to target-core
1427 	 */
1428 	if (flags & TARGET_SCF_BIDI_OP)
1429 		se_cmd->se_cmd_flags |= SCF_BIDI;
1430 	/*
1431 	 * Locate se_lun pointer and attach it to struct se_cmd
1432 	 */
1433 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1434 	if (rc) {
1435 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1436 		target_put_sess_cmd(se_sess, se_cmd);
1437 		return 0;
1438 	}
1439 
1440 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1441 	if (rc != 0) {
1442 		transport_generic_request_failure(se_cmd, rc);
1443 		return 0;
1444 	}
1445 
1446 	/*
1447 	 * Save pointers for SGLs containing protection information,
1448 	 * if present.
1449 	 */
1450 	if (sgl_prot_count) {
1451 		se_cmd->t_prot_sg = sgl_prot;
1452 		se_cmd->t_prot_nents = sgl_prot_count;
1453 	}
1454 
1455 	/*
1456 	 * When a non zero sgl_count has been passed perform SGL passthrough
1457 	 * mapping for pre-allocated fabric memory instead of having target
1458 	 * core perform an internal SGL allocation..
1459 	 */
1460 	if (sgl_count != 0) {
1461 		BUG_ON(!sgl);
1462 
1463 		/*
1464 		 * A work-around for tcm_loop as some userspace code via
1465 		 * scsi-generic do not memset their associated read buffers,
1466 		 * so go ahead and do that here for type non-data CDBs.  Also
1467 		 * note that this is currently guaranteed to be a single SGL
1468 		 * for this case by target core in target_setup_cmd_from_cdb()
1469 		 * -> transport_generic_cmd_sequencer().
1470 		 */
1471 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1472 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1473 			unsigned char *buf = NULL;
1474 
1475 			if (sgl)
1476 				buf = kmap(sg_page(sgl)) + sgl->offset;
1477 
1478 			if (buf) {
1479 				memset(buf, 0, sgl->length);
1480 				kunmap(sg_page(sgl));
1481 			}
1482 		}
1483 
1484 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1485 				sgl_bidi, sgl_bidi_count);
1486 		if (rc != 0) {
1487 			transport_generic_request_failure(se_cmd, rc);
1488 			return 0;
1489 		}
1490 	}
1491 
1492 	/*
1493 	 * Check if we need to delay processing because of ALUA
1494 	 * Active/NonOptimized primary access state..
1495 	 */
1496 	core_alua_check_nonop_delay(se_cmd);
1497 
1498 	transport_handle_cdb_direct(se_cmd);
1499 	return 0;
1500 }
1501 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1502 
1503 /*
1504  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1505  *
1506  * @se_cmd: command descriptor to submit
1507  * @se_sess: associated se_sess for endpoint
1508  * @cdb: pointer to SCSI CDB
1509  * @sense: pointer to SCSI sense buffer
1510  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1511  * @data_length: fabric expected data transfer length
1512  * @task_addr: SAM task attribute
1513  * @data_dir: DMA data direction
1514  * @flags: flags for command submission from target_sc_flags_tables
1515  *
1516  * Returns non zero to signal active I/O shutdown failure.  All other
1517  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1518  * but still return zero here.
1519  *
1520  * This may only be called from process context, and also currently
1521  * assumes internal allocation of fabric payload buffer by target-core.
1522  *
1523  * It also assumes interal target core SGL memory allocation.
1524  */
1525 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1526 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1527 		u32 data_length, int task_attr, int data_dir, int flags)
1528 {
1529 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1530 			unpacked_lun, data_length, task_attr, data_dir,
1531 			flags, NULL, 0, NULL, 0, NULL, 0);
1532 }
1533 EXPORT_SYMBOL(target_submit_cmd);
1534 
1535 static void target_complete_tmr_failure(struct work_struct *work)
1536 {
1537 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1538 
1539 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1540 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1541 
1542 	transport_cmd_check_stop_to_fabric(se_cmd);
1543 }
1544 
1545 /**
1546  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1547  *                     for TMR CDBs
1548  *
1549  * @se_cmd: command descriptor to submit
1550  * @se_sess: associated se_sess for endpoint
1551  * @sense: pointer to SCSI sense buffer
1552  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1553  * @fabric_context: fabric context for TMR req
1554  * @tm_type: Type of TM request
1555  * @gfp: gfp type for caller
1556  * @tag: referenced task tag for TMR_ABORT_TASK
1557  * @flags: submit cmd flags
1558  *
1559  * Callable from all contexts.
1560  **/
1561 
1562 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1563 		unsigned char *sense, u32 unpacked_lun,
1564 		void *fabric_tmr_ptr, unsigned char tm_type,
1565 		gfp_t gfp, unsigned int tag, int flags)
1566 {
1567 	struct se_portal_group *se_tpg;
1568 	int ret;
1569 
1570 	se_tpg = se_sess->se_tpg;
1571 	BUG_ON(!se_tpg);
1572 
1573 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1574 			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1575 	/*
1576 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1577 	 * allocation failure.
1578 	 */
1579 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1580 	if (ret < 0)
1581 		return -ENOMEM;
1582 
1583 	if (tm_type == TMR_ABORT_TASK)
1584 		se_cmd->se_tmr_req->ref_task_tag = tag;
1585 
1586 	/* See target_submit_cmd for commentary */
1587 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1588 	if (ret) {
1589 		core_tmr_release_req(se_cmd->se_tmr_req);
1590 		return ret;
1591 	}
1592 
1593 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1594 	if (ret) {
1595 		/*
1596 		 * For callback during failure handling, push this work off
1597 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1598 		 */
1599 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1600 		schedule_work(&se_cmd->work);
1601 		return 0;
1602 	}
1603 	transport_generic_handle_tmr(se_cmd);
1604 	return 0;
1605 }
1606 EXPORT_SYMBOL(target_submit_tmr);
1607 
1608 /*
1609  * If the cmd is active, request it to be stopped and sleep until it
1610  * has completed.
1611  */
1612 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1613 	__releases(&cmd->t_state_lock)
1614 	__acquires(&cmd->t_state_lock)
1615 {
1616 	bool was_active = false;
1617 
1618 	if (cmd->transport_state & CMD_T_BUSY) {
1619 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1620 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1621 
1622 		pr_debug("cmd %p waiting to complete\n", cmd);
1623 		wait_for_completion(&cmd->task_stop_comp);
1624 		pr_debug("cmd %p stopped successfully\n", cmd);
1625 
1626 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1627 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1628 		cmd->transport_state &= ~CMD_T_BUSY;
1629 		was_active = true;
1630 	}
1631 
1632 	return was_active;
1633 }
1634 
1635 /*
1636  * Handle SAM-esque emulation for generic transport request failures.
1637  */
1638 void transport_generic_request_failure(struct se_cmd *cmd,
1639 		sense_reason_t sense_reason)
1640 {
1641 	int ret = 0;
1642 
1643 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1644 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1645 		cmd->t_task_cdb[0]);
1646 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1647 		cmd->se_tfo->get_cmd_state(cmd),
1648 		cmd->t_state, sense_reason);
1649 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1650 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1651 		(cmd->transport_state & CMD_T_STOP) != 0,
1652 		(cmd->transport_state & CMD_T_SENT) != 0);
1653 
1654 	/*
1655 	 * For SAM Task Attribute emulation for failed struct se_cmd
1656 	 */
1657 	transport_complete_task_attr(cmd);
1658 	/*
1659 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1660 	 * callback is expected to drop the per device ->caw_sem.
1661 	 */
1662 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1663 	     cmd->transport_complete_callback)
1664 		cmd->transport_complete_callback(cmd, false);
1665 
1666 	switch (sense_reason) {
1667 	case TCM_NON_EXISTENT_LUN:
1668 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1669 	case TCM_INVALID_CDB_FIELD:
1670 	case TCM_INVALID_PARAMETER_LIST:
1671 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1672 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1673 	case TCM_UNKNOWN_MODE_PAGE:
1674 	case TCM_WRITE_PROTECTED:
1675 	case TCM_ADDRESS_OUT_OF_RANGE:
1676 	case TCM_CHECK_CONDITION_ABORT_CMD:
1677 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1678 	case TCM_CHECK_CONDITION_NOT_READY:
1679 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1680 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1681 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1682 		break;
1683 	case TCM_OUT_OF_RESOURCES:
1684 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1685 		break;
1686 	case TCM_RESERVATION_CONFLICT:
1687 		/*
1688 		 * No SENSE Data payload for this case, set SCSI Status
1689 		 * and queue the response to $FABRIC_MOD.
1690 		 *
1691 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1692 		 */
1693 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1694 		/*
1695 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1696 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1697 		 * CONFLICT STATUS.
1698 		 *
1699 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1700 		 */
1701 		if (cmd->se_sess &&
1702 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1703 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1704 				cmd->orig_fe_lun, 0x2C,
1705 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1706 
1707 		trace_target_cmd_complete(cmd);
1708 		ret = cmd->se_tfo-> queue_status(cmd);
1709 		if (ret == -EAGAIN || ret == -ENOMEM)
1710 			goto queue_full;
1711 		goto check_stop;
1712 	default:
1713 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1714 			cmd->t_task_cdb[0], sense_reason);
1715 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1716 		break;
1717 	}
1718 
1719 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1720 	if (ret == -EAGAIN || ret == -ENOMEM)
1721 		goto queue_full;
1722 
1723 check_stop:
1724 	transport_lun_remove_cmd(cmd);
1725 	if (!transport_cmd_check_stop_to_fabric(cmd))
1726 		;
1727 	return;
1728 
1729 queue_full:
1730 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1731 	transport_handle_queue_full(cmd, cmd->se_dev);
1732 }
1733 EXPORT_SYMBOL(transport_generic_request_failure);
1734 
1735 void __target_execute_cmd(struct se_cmd *cmd)
1736 {
1737 	sense_reason_t ret;
1738 
1739 	if (cmd->execute_cmd) {
1740 		ret = cmd->execute_cmd(cmd);
1741 		if (ret) {
1742 			spin_lock_irq(&cmd->t_state_lock);
1743 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1744 			spin_unlock_irq(&cmd->t_state_lock);
1745 
1746 			transport_generic_request_failure(cmd, ret);
1747 		}
1748 	}
1749 }
1750 
1751 static int target_write_prot_action(struct se_cmd *cmd)
1752 {
1753 	u32 sectors;
1754 	/*
1755 	 * Perform WRITE_INSERT of PI using software emulation when backend
1756 	 * device has PI enabled, if the transport has not already generated
1757 	 * PI using hardware WRITE_INSERT offload.
1758 	 */
1759 	switch (cmd->prot_op) {
1760 	case TARGET_PROT_DOUT_INSERT:
1761 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1762 			sbc_dif_generate(cmd);
1763 		break;
1764 	case TARGET_PROT_DOUT_STRIP:
1765 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1766 			break;
1767 
1768 		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1769 		cmd->pi_err = sbc_dif_verify_write(cmd, cmd->t_task_lba,
1770 						   sectors, 0, NULL, 0);
1771 		if (unlikely(cmd->pi_err)) {
1772 			spin_lock_irq(&cmd->t_state_lock);
1773 			cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT;
1774 			spin_unlock_irq(&cmd->t_state_lock);
1775 			transport_generic_request_failure(cmd, cmd->pi_err);
1776 			return -1;
1777 		}
1778 		break;
1779 	default:
1780 		break;
1781 	}
1782 
1783 	return 0;
1784 }
1785 
1786 static bool target_handle_task_attr(struct se_cmd *cmd)
1787 {
1788 	struct se_device *dev = cmd->se_dev;
1789 
1790 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1791 		return false;
1792 
1793 	/*
1794 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1795 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1796 	 */
1797 	switch (cmd->sam_task_attr) {
1798 	case TCM_HEAD_TAG:
1799 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1800 			 "se_ordered_id: %u\n",
1801 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1802 		return false;
1803 	case TCM_ORDERED_TAG:
1804 		atomic_inc_mb(&dev->dev_ordered_sync);
1805 
1806 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1807 			 " se_ordered_id: %u\n",
1808 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1809 
1810 		/*
1811 		 * Execute an ORDERED command if no other older commands
1812 		 * exist that need to be completed first.
1813 		 */
1814 		if (!atomic_read(&dev->simple_cmds))
1815 			return false;
1816 		break;
1817 	default:
1818 		/*
1819 		 * For SIMPLE and UNTAGGED Task Attribute commands
1820 		 */
1821 		atomic_inc_mb(&dev->simple_cmds);
1822 		break;
1823 	}
1824 
1825 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1826 		return false;
1827 
1828 	spin_lock(&dev->delayed_cmd_lock);
1829 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1830 	spin_unlock(&dev->delayed_cmd_lock);
1831 
1832 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1833 		" delayed CMD list, se_ordered_id: %u\n",
1834 		cmd->t_task_cdb[0], cmd->sam_task_attr,
1835 		cmd->se_ordered_id);
1836 	return true;
1837 }
1838 
1839 void target_execute_cmd(struct se_cmd *cmd)
1840 {
1841 	/*
1842 	 * If the received CDB has aleady been aborted stop processing it here.
1843 	 */
1844 	if (transport_check_aborted_status(cmd, 1))
1845 		return;
1846 
1847 	/*
1848 	 * Determine if frontend context caller is requesting the stopping of
1849 	 * this command for frontend exceptions.
1850 	 */
1851 	spin_lock_irq(&cmd->t_state_lock);
1852 	if (cmd->transport_state & CMD_T_STOP) {
1853 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1854 			__func__, __LINE__,
1855 			cmd->se_tfo->get_task_tag(cmd));
1856 
1857 		spin_unlock_irq(&cmd->t_state_lock);
1858 		complete_all(&cmd->t_transport_stop_comp);
1859 		return;
1860 	}
1861 
1862 	cmd->t_state = TRANSPORT_PROCESSING;
1863 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1864 	spin_unlock_irq(&cmd->t_state_lock);
1865 
1866 	if (target_write_prot_action(cmd))
1867 		return;
1868 
1869 	if (target_handle_task_attr(cmd)) {
1870 		spin_lock_irq(&cmd->t_state_lock);
1871 		cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT;
1872 		spin_unlock_irq(&cmd->t_state_lock);
1873 		return;
1874 	}
1875 
1876 	__target_execute_cmd(cmd);
1877 }
1878 EXPORT_SYMBOL(target_execute_cmd);
1879 
1880 /*
1881  * Process all commands up to the last received ORDERED task attribute which
1882  * requires another blocking boundary
1883  */
1884 static void target_restart_delayed_cmds(struct se_device *dev)
1885 {
1886 	for (;;) {
1887 		struct se_cmd *cmd;
1888 
1889 		spin_lock(&dev->delayed_cmd_lock);
1890 		if (list_empty(&dev->delayed_cmd_list)) {
1891 			spin_unlock(&dev->delayed_cmd_lock);
1892 			break;
1893 		}
1894 
1895 		cmd = list_entry(dev->delayed_cmd_list.next,
1896 				 struct se_cmd, se_delayed_node);
1897 		list_del(&cmd->se_delayed_node);
1898 		spin_unlock(&dev->delayed_cmd_lock);
1899 
1900 		__target_execute_cmd(cmd);
1901 
1902 		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1903 			break;
1904 	}
1905 }
1906 
1907 /*
1908  * Called from I/O completion to determine which dormant/delayed
1909  * and ordered cmds need to have their tasks added to the execution queue.
1910  */
1911 static void transport_complete_task_attr(struct se_cmd *cmd)
1912 {
1913 	struct se_device *dev = cmd->se_dev;
1914 
1915 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1916 		return;
1917 
1918 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1919 		atomic_dec_mb(&dev->simple_cmds);
1920 		dev->dev_cur_ordered_id++;
1921 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1922 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1923 			cmd->se_ordered_id);
1924 	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1925 		dev->dev_cur_ordered_id++;
1926 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1927 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1928 			cmd->se_ordered_id);
1929 	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1930 		atomic_dec_mb(&dev->dev_ordered_sync);
1931 
1932 		dev->dev_cur_ordered_id++;
1933 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1934 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1935 	}
1936 
1937 	target_restart_delayed_cmds(dev);
1938 }
1939 
1940 static void transport_complete_qf(struct se_cmd *cmd)
1941 {
1942 	int ret = 0;
1943 
1944 	transport_complete_task_attr(cmd);
1945 
1946 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1947 		trace_target_cmd_complete(cmd);
1948 		ret = cmd->se_tfo->queue_status(cmd);
1949 		goto out;
1950 	}
1951 
1952 	switch (cmd->data_direction) {
1953 	case DMA_FROM_DEVICE:
1954 		trace_target_cmd_complete(cmd);
1955 		ret = cmd->se_tfo->queue_data_in(cmd);
1956 		break;
1957 	case DMA_TO_DEVICE:
1958 		if (cmd->se_cmd_flags & SCF_BIDI) {
1959 			ret = cmd->se_tfo->queue_data_in(cmd);
1960 			if (ret < 0)
1961 				break;
1962 		}
1963 		/* Fall through for DMA_TO_DEVICE */
1964 	case DMA_NONE:
1965 		trace_target_cmd_complete(cmd);
1966 		ret = cmd->se_tfo->queue_status(cmd);
1967 		break;
1968 	default:
1969 		break;
1970 	}
1971 
1972 out:
1973 	if (ret < 0) {
1974 		transport_handle_queue_full(cmd, cmd->se_dev);
1975 		return;
1976 	}
1977 	transport_lun_remove_cmd(cmd);
1978 	transport_cmd_check_stop_to_fabric(cmd);
1979 }
1980 
1981 static void transport_handle_queue_full(
1982 	struct se_cmd *cmd,
1983 	struct se_device *dev)
1984 {
1985 	spin_lock_irq(&dev->qf_cmd_lock);
1986 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1987 	atomic_inc_mb(&dev->dev_qf_count);
1988 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1989 
1990 	schedule_work(&cmd->se_dev->qf_work_queue);
1991 }
1992 
1993 static bool target_read_prot_action(struct se_cmd *cmd)
1994 {
1995 	sense_reason_t rc;
1996 
1997 	switch (cmd->prot_op) {
1998 	case TARGET_PROT_DIN_STRIP:
1999 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2000 			rc = sbc_dif_read_strip(cmd);
2001 			if (rc) {
2002 				cmd->pi_err = rc;
2003 				return true;
2004 			}
2005 		}
2006 		break;
2007 	case TARGET_PROT_DIN_INSERT:
2008 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2009 			break;
2010 
2011 		sbc_dif_generate(cmd);
2012 		break;
2013 	default:
2014 		break;
2015 	}
2016 
2017 	return false;
2018 }
2019 
2020 static void target_complete_ok_work(struct work_struct *work)
2021 {
2022 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2023 	int ret;
2024 
2025 	/*
2026 	 * Check if we need to move delayed/dormant tasks from cmds on the
2027 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2028 	 * Attribute.
2029 	 */
2030 	transport_complete_task_attr(cmd);
2031 
2032 	/*
2033 	 * Check to schedule QUEUE_FULL work, or execute an existing
2034 	 * cmd->transport_qf_callback()
2035 	 */
2036 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2037 		schedule_work(&cmd->se_dev->qf_work_queue);
2038 
2039 	/*
2040 	 * Check if we need to send a sense buffer from
2041 	 * the struct se_cmd in question.
2042 	 */
2043 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2044 		WARN_ON(!cmd->scsi_status);
2045 		ret = transport_send_check_condition_and_sense(
2046 					cmd, 0, 1);
2047 		if (ret == -EAGAIN || ret == -ENOMEM)
2048 			goto queue_full;
2049 
2050 		transport_lun_remove_cmd(cmd);
2051 		transport_cmd_check_stop_to_fabric(cmd);
2052 		return;
2053 	}
2054 	/*
2055 	 * Check for a callback, used by amongst other things
2056 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2057 	 */
2058 	if (cmd->transport_complete_callback) {
2059 		sense_reason_t rc;
2060 
2061 		rc = cmd->transport_complete_callback(cmd, true);
2062 		if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
2063 			if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2064 			    !cmd->data_length)
2065 				goto queue_rsp;
2066 
2067 			return;
2068 		} else if (rc) {
2069 			ret = transport_send_check_condition_and_sense(cmd,
2070 						rc, 0);
2071 			if (ret == -EAGAIN || ret == -ENOMEM)
2072 				goto queue_full;
2073 
2074 			transport_lun_remove_cmd(cmd);
2075 			transport_cmd_check_stop_to_fabric(cmd);
2076 			return;
2077 		}
2078 	}
2079 
2080 queue_rsp:
2081 	switch (cmd->data_direction) {
2082 	case DMA_FROM_DEVICE:
2083 		spin_lock(&cmd->se_lun->lun_sep_lock);
2084 		if (cmd->se_lun->lun_sep) {
2085 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2086 					cmd->data_length;
2087 		}
2088 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2089 		/*
2090 		 * Perform READ_STRIP of PI using software emulation when
2091 		 * backend had PI enabled, if the transport will not be
2092 		 * performing hardware READ_STRIP offload.
2093 		 */
2094 		if (target_read_prot_action(cmd)) {
2095 			ret = transport_send_check_condition_and_sense(cmd,
2096 						cmd->pi_err, 0);
2097 			if (ret == -EAGAIN || ret == -ENOMEM)
2098 				goto queue_full;
2099 
2100 			transport_lun_remove_cmd(cmd);
2101 			transport_cmd_check_stop_to_fabric(cmd);
2102 			return;
2103 		}
2104 
2105 		trace_target_cmd_complete(cmd);
2106 		ret = cmd->se_tfo->queue_data_in(cmd);
2107 		if (ret == -EAGAIN || ret == -ENOMEM)
2108 			goto queue_full;
2109 		break;
2110 	case DMA_TO_DEVICE:
2111 		spin_lock(&cmd->se_lun->lun_sep_lock);
2112 		if (cmd->se_lun->lun_sep) {
2113 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2114 				cmd->data_length;
2115 		}
2116 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2117 		/*
2118 		 * Check if we need to send READ payload for BIDI-COMMAND
2119 		 */
2120 		if (cmd->se_cmd_flags & SCF_BIDI) {
2121 			spin_lock(&cmd->se_lun->lun_sep_lock);
2122 			if (cmd->se_lun->lun_sep) {
2123 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2124 					cmd->data_length;
2125 			}
2126 			spin_unlock(&cmd->se_lun->lun_sep_lock);
2127 			ret = cmd->se_tfo->queue_data_in(cmd);
2128 			if (ret == -EAGAIN || ret == -ENOMEM)
2129 				goto queue_full;
2130 			break;
2131 		}
2132 		/* Fall through for DMA_TO_DEVICE */
2133 	case DMA_NONE:
2134 		trace_target_cmd_complete(cmd);
2135 		ret = cmd->se_tfo->queue_status(cmd);
2136 		if (ret == -EAGAIN || ret == -ENOMEM)
2137 			goto queue_full;
2138 		break;
2139 	default:
2140 		break;
2141 	}
2142 
2143 	transport_lun_remove_cmd(cmd);
2144 	transport_cmd_check_stop_to_fabric(cmd);
2145 	return;
2146 
2147 queue_full:
2148 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2149 		" data_direction: %d\n", cmd, cmd->data_direction);
2150 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2151 	transport_handle_queue_full(cmd, cmd->se_dev);
2152 }
2153 
2154 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2155 {
2156 	struct scatterlist *sg;
2157 	int count;
2158 
2159 	for_each_sg(sgl, sg, nents, count)
2160 		__free_page(sg_page(sg));
2161 
2162 	kfree(sgl);
2163 }
2164 
2165 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2166 {
2167 	/*
2168 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2169 	 * emulation, and free + reset pointers if necessary..
2170 	 */
2171 	if (!cmd->t_data_sg_orig)
2172 		return;
2173 
2174 	kfree(cmd->t_data_sg);
2175 	cmd->t_data_sg = cmd->t_data_sg_orig;
2176 	cmd->t_data_sg_orig = NULL;
2177 	cmd->t_data_nents = cmd->t_data_nents_orig;
2178 	cmd->t_data_nents_orig = 0;
2179 }
2180 
2181 static inline void transport_free_pages(struct se_cmd *cmd)
2182 {
2183 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2184 		/*
2185 		 * Release special case READ buffer payload required for
2186 		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2187 		 */
2188 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2189 			transport_free_sgl(cmd->t_bidi_data_sg,
2190 					   cmd->t_bidi_data_nents);
2191 			cmd->t_bidi_data_sg = NULL;
2192 			cmd->t_bidi_data_nents = 0;
2193 		}
2194 		transport_reset_sgl_orig(cmd);
2195 		return;
2196 	}
2197 	transport_reset_sgl_orig(cmd);
2198 
2199 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2200 	cmd->t_data_sg = NULL;
2201 	cmd->t_data_nents = 0;
2202 
2203 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2204 	cmd->t_bidi_data_sg = NULL;
2205 	cmd->t_bidi_data_nents = 0;
2206 
2207 	transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2208 	cmd->t_prot_sg = NULL;
2209 	cmd->t_prot_nents = 0;
2210 }
2211 
2212 /**
2213  * transport_release_cmd - free a command
2214  * @cmd:       command to free
2215  *
2216  * This routine unconditionally frees a command, and reference counting
2217  * or list removal must be done in the caller.
2218  */
2219 static int transport_release_cmd(struct se_cmd *cmd)
2220 {
2221 	BUG_ON(!cmd->se_tfo);
2222 
2223 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2224 		core_tmr_release_req(cmd->se_tmr_req);
2225 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2226 		kfree(cmd->t_task_cdb);
2227 	/*
2228 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2229 	 * the kref and call ->release_cmd() in kref callback.
2230 	 */
2231 	return target_put_sess_cmd(cmd->se_sess, cmd);
2232 }
2233 
2234 /**
2235  * transport_put_cmd - release a reference to a command
2236  * @cmd:       command to release
2237  *
2238  * This routine releases our reference to the command and frees it if possible.
2239  */
2240 static int transport_put_cmd(struct se_cmd *cmd)
2241 {
2242 	transport_free_pages(cmd);
2243 	return transport_release_cmd(cmd);
2244 }
2245 
2246 void *transport_kmap_data_sg(struct se_cmd *cmd)
2247 {
2248 	struct scatterlist *sg = cmd->t_data_sg;
2249 	struct page **pages;
2250 	int i;
2251 
2252 	/*
2253 	 * We need to take into account a possible offset here for fabrics like
2254 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2255 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2256 	 */
2257 	if (!cmd->t_data_nents)
2258 		return NULL;
2259 
2260 	BUG_ON(!sg);
2261 	if (cmd->t_data_nents == 1)
2262 		return kmap(sg_page(sg)) + sg->offset;
2263 
2264 	/* >1 page. use vmap */
2265 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2266 	if (!pages)
2267 		return NULL;
2268 
2269 	/* convert sg[] to pages[] */
2270 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2271 		pages[i] = sg_page(sg);
2272 	}
2273 
2274 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2275 	kfree(pages);
2276 	if (!cmd->t_data_vmap)
2277 		return NULL;
2278 
2279 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2280 }
2281 EXPORT_SYMBOL(transport_kmap_data_sg);
2282 
2283 void transport_kunmap_data_sg(struct se_cmd *cmd)
2284 {
2285 	if (!cmd->t_data_nents) {
2286 		return;
2287 	} else if (cmd->t_data_nents == 1) {
2288 		kunmap(sg_page(cmd->t_data_sg));
2289 		return;
2290 	}
2291 
2292 	vunmap(cmd->t_data_vmap);
2293 	cmd->t_data_vmap = NULL;
2294 }
2295 EXPORT_SYMBOL(transport_kunmap_data_sg);
2296 
2297 int
2298 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2299 		 bool zero_page)
2300 {
2301 	struct scatterlist *sg;
2302 	struct page *page;
2303 	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2304 	unsigned int nent;
2305 	int i = 0;
2306 
2307 	nent = DIV_ROUND_UP(length, PAGE_SIZE);
2308 	sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2309 	if (!sg)
2310 		return -ENOMEM;
2311 
2312 	sg_init_table(sg, nent);
2313 
2314 	while (length) {
2315 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2316 		page = alloc_page(GFP_KERNEL | zero_flag);
2317 		if (!page)
2318 			goto out;
2319 
2320 		sg_set_page(&sg[i], page, page_len, 0);
2321 		length -= page_len;
2322 		i++;
2323 	}
2324 	*sgl = sg;
2325 	*nents = nent;
2326 	return 0;
2327 
2328 out:
2329 	while (i > 0) {
2330 		i--;
2331 		__free_page(sg_page(&sg[i]));
2332 	}
2333 	kfree(sg);
2334 	return -ENOMEM;
2335 }
2336 
2337 /*
2338  * Allocate any required resources to execute the command.  For writes we
2339  * might not have the payload yet, so notify the fabric via a call to
2340  * ->write_pending instead. Otherwise place it on the execution queue.
2341  */
2342 sense_reason_t
2343 transport_generic_new_cmd(struct se_cmd *cmd)
2344 {
2345 	int ret = 0;
2346 	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2347 
2348 	/*
2349 	 * Determine is the TCM fabric module has already allocated physical
2350 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2351 	 * beforehand.
2352 	 */
2353 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2354 	    cmd->data_length) {
2355 
2356 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2357 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2358 			u32 bidi_length;
2359 
2360 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2361 				bidi_length = cmd->t_task_nolb *
2362 					      cmd->se_dev->dev_attrib.block_size;
2363 			else
2364 				bidi_length = cmd->data_length;
2365 
2366 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2367 					       &cmd->t_bidi_data_nents,
2368 					       bidi_length, zero_flag);
2369 			if (ret < 0)
2370 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2371 		}
2372 
2373 		if (cmd->prot_op != TARGET_PROT_NORMAL) {
2374 			ret = target_alloc_sgl(&cmd->t_prot_sg,
2375 					       &cmd->t_prot_nents,
2376 					       cmd->prot_length, true);
2377 			if (ret < 0)
2378 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2379 		}
2380 
2381 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2382 				       cmd->data_length, zero_flag);
2383 		if (ret < 0)
2384 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2385 	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2386 		    cmd->data_length) {
2387 		/*
2388 		 * Special case for COMPARE_AND_WRITE with fabrics
2389 		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2390 		 */
2391 		u32 caw_length = cmd->t_task_nolb *
2392 				 cmd->se_dev->dev_attrib.block_size;
2393 
2394 		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2395 				       &cmd->t_bidi_data_nents,
2396 				       caw_length, zero_flag);
2397 		if (ret < 0)
2398 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2399 	}
2400 	/*
2401 	 * If this command is not a write we can execute it right here,
2402 	 * for write buffers we need to notify the fabric driver first
2403 	 * and let it call back once the write buffers are ready.
2404 	 */
2405 	target_add_to_state_list(cmd);
2406 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2407 		target_execute_cmd(cmd);
2408 		return 0;
2409 	}
2410 	transport_cmd_check_stop(cmd, false, true);
2411 
2412 	ret = cmd->se_tfo->write_pending(cmd);
2413 	if (ret == -EAGAIN || ret == -ENOMEM)
2414 		goto queue_full;
2415 
2416 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2417 	WARN_ON(ret);
2418 
2419 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2420 
2421 queue_full:
2422 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2423 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2424 	transport_handle_queue_full(cmd, cmd->se_dev);
2425 	return 0;
2426 }
2427 EXPORT_SYMBOL(transport_generic_new_cmd);
2428 
2429 static void transport_write_pending_qf(struct se_cmd *cmd)
2430 {
2431 	int ret;
2432 
2433 	ret = cmd->se_tfo->write_pending(cmd);
2434 	if (ret == -EAGAIN || ret == -ENOMEM) {
2435 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2436 			 cmd);
2437 		transport_handle_queue_full(cmd, cmd->se_dev);
2438 	}
2439 }
2440 
2441 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2442 {
2443 	unsigned long flags;
2444 	int ret = 0;
2445 
2446 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2447 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2448 			 transport_wait_for_tasks(cmd);
2449 
2450 		ret = transport_release_cmd(cmd);
2451 	} else {
2452 		if (wait_for_tasks)
2453 			transport_wait_for_tasks(cmd);
2454 		/*
2455 		 * Handle WRITE failure case where transport_generic_new_cmd()
2456 		 * has already added se_cmd to state_list, but fabric has
2457 		 * failed command before I/O submission.
2458 		 */
2459 		if (cmd->state_active) {
2460 			spin_lock_irqsave(&cmd->t_state_lock, flags);
2461 			target_remove_from_state_list(cmd);
2462 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2463 		}
2464 
2465 		if (cmd->se_lun)
2466 			transport_lun_remove_cmd(cmd);
2467 
2468 		ret = transport_put_cmd(cmd);
2469 	}
2470 	return ret;
2471 }
2472 EXPORT_SYMBOL(transport_generic_free_cmd);
2473 
2474 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2475  * @se_sess:	session to reference
2476  * @se_cmd:	command descriptor to add
2477  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2478  */
2479 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2480 			       bool ack_kref)
2481 {
2482 	unsigned long flags;
2483 	int ret = 0;
2484 
2485 	/*
2486 	 * Add a second kref if the fabric caller is expecting to handle
2487 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2488 	 * invocations before se_cmd descriptor release.
2489 	 */
2490 	if (ack_kref)
2491 		kref_get(&se_cmd->cmd_kref);
2492 
2493 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2494 	if (se_sess->sess_tearing_down) {
2495 		ret = -ESHUTDOWN;
2496 		goto out;
2497 	}
2498 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2499 out:
2500 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2501 
2502 	if (ret && ack_kref)
2503 		target_put_sess_cmd(se_sess, se_cmd);
2504 
2505 	return ret;
2506 }
2507 EXPORT_SYMBOL(target_get_sess_cmd);
2508 
2509 static void target_release_cmd_kref(struct kref *kref)
2510 		__releases(&se_cmd->se_sess->sess_cmd_lock)
2511 {
2512 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2513 	struct se_session *se_sess = se_cmd->se_sess;
2514 
2515 	if (list_empty(&se_cmd->se_cmd_list)) {
2516 		spin_unlock(&se_sess->sess_cmd_lock);
2517 		se_cmd->se_tfo->release_cmd(se_cmd);
2518 		return;
2519 	}
2520 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2521 		spin_unlock(&se_sess->sess_cmd_lock);
2522 		complete(&se_cmd->cmd_wait_comp);
2523 		return;
2524 	}
2525 	list_del(&se_cmd->se_cmd_list);
2526 	spin_unlock(&se_sess->sess_cmd_lock);
2527 
2528 	se_cmd->se_tfo->release_cmd(se_cmd);
2529 }
2530 
2531 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2532  * @se_sess:	session to reference
2533  * @se_cmd:	command descriptor to drop
2534  */
2535 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2536 {
2537 	if (!se_sess) {
2538 		se_cmd->se_tfo->release_cmd(se_cmd);
2539 		return 1;
2540 	}
2541 	return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2542 			&se_sess->sess_cmd_lock);
2543 }
2544 EXPORT_SYMBOL(target_put_sess_cmd);
2545 
2546 /* target_sess_cmd_list_set_waiting - Flag all commands in
2547  *         sess_cmd_list to complete cmd_wait_comp.  Set
2548  *         sess_tearing_down so no more commands are queued.
2549  * @se_sess:	session to flag
2550  */
2551 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2552 {
2553 	struct se_cmd *se_cmd;
2554 	unsigned long flags;
2555 
2556 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2557 	if (se_sess->sess_tearing_down) {
2558 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2559 		return;
2560 	}
2561 	se_sess->sess_tearing_down = 1;
2562 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2563 
2564 	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2565 		se_cmd->cmd_wait_set = 1;
2566 
2567 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2568 }
2569 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2570 
2571 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2572  * @se_sess:    session to wait for active I/O
2573  */
2574 void target_wait_for_sess_cmds(struct se_session *se_sess)
2575 {
2576 	struct se_cmd *se_cmd, *tmp_cmd;
2577 	unsigned long flags;
2578 
2579 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2580 				&se_sess->sess_wait_list, se_cmd_list) {
2581 		list_del(&se_cmd->se_cmd_list);
2582 
2583 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2584 			" %d\n", se_cmd, se_cmd->t_state,
2585 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2586 
2587 		wait_for_completion(&se_cmd->cmd_wait_comp);
2588 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2589 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2590 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2591 
2592 		se_cmd->se_tfo->release_cmd(se_cmd);
2593 	}
2594 
2595 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2596 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2597 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2598 
2599 }
2600 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2601 
2602 static int transport_clear_lun_ref_thread(void *p)
2603 {
2604 	struct se_lun *lun = p;
2605 
2606 	percpu_ref_kill(&lun->lun_ref);
2607 
2608 	wait_for_completion(&lun->lun_ref_comp);
2609 	complete(&lun->lun_shutdown_comp);
2610 
2611 	return 0;
2612 }
2613 
2614 int transport_clear_lun_ref(struct se_lun *lun)
2615 {
2616 	struct task_struct *kt;
2617 
2618 	kt = kthread_run(transport_clear_lun_ref_thread, lun,
2619 			"tcm_cl_%u", lun->unpacked_lun);
2620 	if (IS_ERR(kt)) {
2621 		pr_err("Unable to start clear_lun thread\n");
2622 		return PTR_ERR(kt);
2623 	}
2624 	wait_for_completion(&lun->lun_shutdown_comp);
2625 
2626 	return 0;
2627 }
2628 
2629 /**
2630  * transport_wait_for_tasks - wait for completion to occur
2631  * @cmd:	command to wait
2632  *
2633  * Called from frontend fabric context to wait for storage engine
2634  * to pause and/or release frontend generated struct se_cmd.
2635  */
2636 bool transport_wait_for_tasks(struct se_cmd *cmd)
2637 {
2638 	unsigned long flags;
2639 
2640 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2641 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2642 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2643 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2644 		return false;
2645 	}
2646 
2647 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2648 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2649 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2650 		return false;
2651 	}
2652 
2653 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2654 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2655 		return false;
2656 	}
2657 
2658 	cmd->transport_state |= CMD_T_STOP;
2659 
2660 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2661 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2662 		cmd, cmd->se_tfo->get_task_tag(cmd),
2663 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2664 
2665 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2666 
2667 	wait_for_completion(&cmd->t_transport_stop_comp);
2668 
2669 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2670 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2671 
2672 	pr_debug("wait_for_tasks: Stopped wait_for_completion("
2673 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2674 		cmd->se_tfo->get_task_tag(cmd));
2675 
2676 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2677 
2678 	return true;
2679 }
2680 EXPORT_SYMBOL(transport_wait_for_tasks);
2681 
2682 static int transport_get_sense_codes(
2683 	struct se_cmd *cmd,
2684 	u8 *asc,
2685 	u8 *ascq)
2686 {
2687 	*asc = cmd->scsi_asc;
2688 	*ascq = cmd->scsi_ascq;
2689 
2690 	return 0;
2691 }
2692 
2693 static
2694 void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
2695 {
2696 	/* Place failed LBA in sense data information descriptor 0. */
2697 	buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
2698 	buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
2699 	buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
2700 	buffer[SPC_VALIDITY_OFFSET] = 0x80;
2701 
2702 	/* Descriptor Information: failing sector */
2703 	put_unaligned_be64(bad_sector, &buffer[12]);
2704 }
2705 
2706 int
2707 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2708 		sense_reason_t reason, int from_transport)
2709 {
2710 	unsigned char *buffer = cmd->sense_buffer;
2711 	unsigned long flags;
2712 	u8 asc = 0, ascq = 0;
2713 
2714 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2715 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2716 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2717 		return 0;
2718 	}
2719 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2720 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2721 
2722 	if (!reason && from_transport)
2723 		goto after_reason;
2724 
2725 	if (!from_transport)
2726 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2727 
2728 	/*
2729 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2730 	 * SENSE KEY values from include/scsi/scsi.h
2731 	 */
2732 	switch (reason) {
2733 	case TCM_NO_SENSE:
2734 		/* CURRENT ERROR */
2735 		buffer[0] = 0x70;
2736 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2737 		/* Not Ready */
2738 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2739 		/* NO ADDITIONAL SENSE INFORMATION */
2740 		buffer[SPC_ASC_KEY_OFFSET] = 0;
2741 		buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2742 		break;
2743 	case TCM_NON_EXISTENT_LUN:
2744 		/* CURRENT ERROR */
2745 		buffer[0] = 0x70;
2746 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2747 		/* ILLEGAL REQUEST */
2748 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2749 		/* LOGICAL UNIT NOT SUPPORTED */
2750 		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2751 		break;
2752 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2753 	case TCM_SECTOR_COUNT_TOO_MANY:
2754 		/* CURRENT ERROR */
2755 		buffer[0] = 0x70;
2756 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2757 		/* ILLEGAL REQUEST */
2758 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2759 		/* INVALID COMMAND OPERATION CODE */
2760 		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2761 		break;
2762 	case TCM_UNKNOWN_MODE_PAGE:
2763 		/* CURRENT ERROR */
2764 		buffer[0] = 0x70;
2765 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2766 		/* ILLEGAL REQUEST */
2767 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2768 		/* INVALID FIELD IN CDB */
2769 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2770 		break;
2771 	case TCM_CHECK_CONDITION_ABORT_CMD:
2772 		/* CURRENT ERROR */
2773 		buffer[0] = 0x70;
2774 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2775 		/* ABORTED COMMAND */
2776 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2777 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2778 		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2779 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2780 		break;
2781 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2782 		/* CURRENT ERROR */
2783 		buffer[0] = 0x70;
2784 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2785 		/* ABORTED COMMAND */
2786 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2787 		/* WRITE ERROR */
2788 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2789 		/* NOT ENOUGH UNSOLICITED DATA */
2790 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2791 		break;
2792 	case TCM_INVALID_CDB_FIELD:
2793 		/* CURRENT ERROR */
2794 		buffer[0] = 0x70;
2795 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2796 		/* ILLEGAL REQUEST */
2797 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2798 		/* INVALID FIELD IN CDB */
2799 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2800 		break;
2801 	case TCM_INVALID_PARAMETER_LIST:
2802 		/* CURRENT ERROR */
2803 		buffer[0] = 0x70;
2804 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2805 		/* ILLEGAL REQUEST */
2806 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2807 		/* INVALID FIELD IN PARAMETER LIST */
2808 		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2809 		break;
2810 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2811 		/* CURRENT ERROR */
2812 		buffer[0] = 0x70;
2813 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2814 		/* ILLEGAL REQUEST */
2815 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2816 		/* PARAMETER LIST LENGTH ERROR */
2817 		buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2818 		break;
2819 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2820 		/* CURRENT ERROR */
2821 		buffer[0] = 0x70;
2822 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2823 		/* ABORTED COMMAND */
2824 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2825 		/* WRITE ERROR */
2826 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2827 		/* UNEXPECTED_UNSOLICITED_DATA */
2828 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2829 		break;
2830 	case TCM_SERVICE_CRC_ERROR:
2831 		/* CURRENT ERROR */
2832 		buffer[0] = 0x70;
2833 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2834 		/* ABORTED COMMAND */
2835 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2836 		/* PROTOCOL SERVICE CRC ERROR */
2837 		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2838 		/* N/A */
2839 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2840 		break;
2841 	case TCM_SNACK_REJECTED:
2842 		/* CURRENT ERROR */
2843 		buffer[0] = 0x70;
2844 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2845 		/* ABORTED COMMAND */
2846 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2847 		/* READ ERROR */
2848 		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2849 		/* FAILED RETRANSMISSION REQUEST */
2850 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2851 		break;
2852 	case TCM_WRITE_PROTECTED:
2853 		/* CURRENT ERROR */
2854 		buffer[0] = 0x70;
2855 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2856 		/* DATA PROTECT */
2857 		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2858 		/* WRITE PROTECTED */
2859 		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2860 		break;
2861 	case TCM_ADDRESS_OUT_OF_RANGE:
2862 		/* CURRENT ERROR */
2863 		buffer[0] = 0x70;
2864 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2865 		/* ILLEGAL REQUEST */
2866 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2867 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2868 		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2869 		break;
2870 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2871 		/* CURRENT ERROR */
2872 		buffer[0] = 0x70;
2873 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2874 		/* UNIT ATTENTION */
2875 		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2876 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2877 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2878 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2879 		break;
2880 	case TCM_CHECK_CONDITION_NOT_READY:
2881 		/* CURRENT ERROR */
2882 		buffer[0] = 0x70;
2883 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2884 		/* Not Ready */
2885 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2886 		transport_get_sense_codes(cmd, &asc, &ascq);
2887 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2888 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2889 		break;
2890 	case TCM_MISCOMPARE_VERIFY:
2891 		/* CURRENT ERROR */
2892 		buffer[0] = 0x70;
2893 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2894 		buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2895 		/* MISCOMPARE DURING VERIFY OPERATION */
2896 		buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2897 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2898 		break;
2899 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2900 		/* CURRENT ERROR */
2901 		buffer[0] = 0x70;
2902 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2903 		/* ILLEGAL REQUEST */
2904 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2905 		/* LOGICAL BLOCK GUARD CHECK FAILED */
2906 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2907 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
2908 		transport_err_sector_info(buffer, cmd->bad_sector);
2909 		break;
2910 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2911 		/* CURRENT ERROR */
2912 		buffer[0] = 0x70;
2913 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2914 		/* ILLEGAL REQUEST */
2915 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2916 		/* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2917 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2918 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
2919 		transport_err_sector_info(buffer, cmd->bad_sector);
2920 		break;
2921 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2922 		/* CURRENT ERROR */
2923 		buffer[0] = 0x70;
2924 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2925 		/* ILLEGAL REQUEST */
2926 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2927 		/* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2928 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2929 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2930 		transport_err_sector_info(buffer, cmd->bad_sector);
2931 		break;
2932 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2933 	default:
2934 		/* CURRENT ERROR */
2935 		buffer[0] = 0x70;
2936 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2937 		/*
2938 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2939 		 * Solaris initiators.  Returning NOT READY instead means the
2940 		 * operations will be retried a finite number of times and we
2941 		 * can survive intermittent errors.
2942 		 */
2943 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2944 		/* LOGICAL UNIT COMMUNICATION FAILURE */
2945 		buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2946 		break;
2947 	}
2948 	/*
2949 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
2950 	 */
2951 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2952 	/*
2953 	 * Automatically padded, this value is encoded in the fabric's
2954 	 * data_length response PDU containing the SCSI defined sense data.
2955 	 */
2956 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2957 
2958 after_reason:
2959 	trace_target_cmd_complete(cmd);
2960 	return cmd->se_tfo->queue_status(cmd);
2961 }
2962 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2963 
2964 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2965 {
2966 	if (!(cmd->transport_state & CMD_T_ABORTED))
2967 		return 0;
2968 
2969 	/*
2970 	 * If cmd has been aborted but either no status is to be sent or it has
2971 	 * already been sent, just return
2972 	 */
2973 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
2974 		return 1;
2975 
2976 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2977 		 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2978 
2979 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2980 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2981 	trace_target_cmd_complete(cmd);
2982 	cmd->se_tfo->queue_status(cmd);
2983 
2984 	return 1;
2985 }
2986 EXPORT_SYMBOL(transport_check_aborted_status);
2987 
2988 void transport_send_task_abort(struct se_cmd *cmd)
2989 {
2990 	unsigned long flags;
2991 
2992 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2993 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
2994 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2995 		return;
2996 	}
2997 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2998 
2999 	/*
3000 	 * If there are still expected incoming fabric WRITEs, we wait
3001 	 * until until they have completed before sending a TASK_ABORTED
3002 	 * response.  This response with TASK_ABORTED status will be
3003 	 * queued back to fabric module by transport_check_aborted_status().
3004 	 */
3005 	if (cmd->data_direction == DMA_TO_DEVICE) {
3006 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3007 			cmd->transport_state |= CMD_T_ABORTED;
3008 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3009 			return;
3010 		}
3011 	}
3012 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3013 
3014 	transport_lun_remove_cmd(cmd);
3015 
3016 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
3017 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
3018 		cmd->se_tfo->get_task_tag(cmd));
3019 
3020 	trace_target_cmd_complete(cmd);
3021 	cmd->se_tfo->queue_status(cmd);
3022 }
3023 
3024 static void target_tmr_work(struct work_struct *work)
3025 {
3026 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3027 	struct se_device *dev = cmd->se_dev;
3028 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3029 	int ret;
3030 
3031 	switch (tmr->function) {
3032 	case TMR_ABORT_TASK:
3033 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3034 		break;
3035 	case TMR_ABORT_TASK_SET:
3036 	case TMR_CLEAR_ACA:
3037 	case TMR_CLEAR_TASK_SET:
3038 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3039 		break;
3040 	case TMR_LUN_RESET:
3041 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3042 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3043 					 TMR_FUNCTION_REJECTED;
3044 		break;
3045 	case TMR_TARGET_WARM_RESET:
3046 		tmr->response = TMR_FUNCTION_REJECTED;
3047 		break;
3048 	case TMR_TARGET_COLD_RESET:
3049 		tmr->response = TMR_FUNCTION_REJECTED;
3050 		break;
3051 	default:
3052 		pr_err("Uknown TMR function: 0x%02x.\n",
3053 				tmr->function);
3054 		tmr->response = TMR_FUNCTION_REJECTED;
3055 		break;
3056 	}
3057 
3058 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3059 	cmd->se_tfo->queue_tm_rsp(cmd);
3060 
3061 	transport_cmd_check_stop_to_fabric(cmd);
3062 }
3063 
3064 int transport_generic_handle_tmr(
3065 	struct se_cmd *cmd)
3066 {
3067 	unsigned long flags;
3068 
3069 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3070 	cmd->transport_state |= CMD_T_ACTIVE;
3071 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3072 
3073 	INIT_WORK(&cmd->work, target_tmr_work);
3074 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3075 	return 0;
3076 }
3077 EXPORT_SYMBOL(transport_generic_handle_tmr);
3078