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