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