xref: /linux/drivers/target/target_core_transport.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
1 /*******************************************************************************
2  * Filename:  target_core_transport.c
3  *
4  * This file contains the Generic Target Engine Core.
5  *
6  * (c) Copyright 2002-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/net.h>
27 #include <linux/delay.h>
28 #include <linux/string.h>
29 #include <linux/timer.h>
30 #include <linux/slab.h>
31 #include <linux/spinlock.h>
32 #include <linux/kthread.h>
33 #include <linux/in.h>
34 #include <linux/cdrom.h>
35 #include <linux/module.h>
36 #include <linux/ratelimit.h>
37 #include <asm/unaligned.h>
38 #include <net/sock.h>
39 #include <net/tcp.h>
40 #include <scsi/scsi.h>
41 #include <scsi/scsi_cmnd.h>
42 #include <scsi/scsi_tcq.h>
43 
44 #include <target/target_core_base.h>
45 #include <target/target_core_backend.h>
46 #include <target/target_core_fabric.h>
47 #include <target/target_core_configfs.h>
48 
49 #include "target_core_internal.h"
50 #include "target_core_alua.h"
51 #include "target_core_pr.h"
52 #include "target_core_ua.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/target.h>
56 
57 static struct workqueue_struct *target_completion_wq;
58 static struct kmem_cache *se_sess_cache;
59 struct kmem_cache *se_ua_cache;
60 struct kmem_cache *t10_pr_reg_cache;
61 struct kmem_cache *t10_alua_lu_gp_cache;
62 struct kmem_cache *t10_alua_lu_gp_mem_cache;
63 struct kmem_cache *t10_alua_tg_pt_gp_cache;
64 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
65 struct kmem_cache *t10_alua_lba_map_cache;
66 struct kmem_cache *t10_alua_lba_map_mem_cache;
67 
68 static void transport_complete_task_attr(struct se_cmd *cmd);
69 static void transport_handle_queue_full(struct se_cmd *cmd,
70 		struct se_device *dev);
71 static int transport_put_cmd(struct se_cmd *cmd);
72 static void target_complete_ok_work(struct work_struct *work);
73 
74 int init_se_kmem_caches(void)
75 {
76 	se_sess_cache = kmem_cache_create("se_sess_cache",
77 			sizeof(struct se_session), __alignof__(struct se_session),
78 			0, NULL);
79 	if (!se_sess_cache) {
80 		pr_err("kmem_cache_create() for struct se_session"
81 				" failed\n");
82 		goto out;
83 	}
84 	se_ua_cache = kmem_cache_create("se_ua_cache",
85 			sizeof(struct se_ua), __alignof__(struct se_ua),
86 			0, NULL);
87 	if (!se_ua_cache) {
88 		pr_err("kmem_cache_create() for struct se_ua failed\n");
89 		goto out_free_sess_cache;
90 	}
91 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
92 			sizeof(struct t10_pr_registration),
93 			__alignof__(struct t10_pr_registration), 0, NULL);
94 	if (!t10_pr_reg_cache) {
95 		pr_err("kmem_cache_create() for struct t10_pr_registration"
96 				" failed\n");
97 		goto out_free_ua_cache;
98 	}
99 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
100 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
101 			0, NULL);
102 	if (!t10_alua_lu_gp_cache) {
103 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
104 				" failed\n");
105 		goto out_free_pr_reg_cache;
106 	}
107 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
108 			sizeof(struct t10_alua_lu_gp_member),
109 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
110 	if (!t10_alua_lu_gp_mem_cache) {
111 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
112 				"cache failed\n");
113 		goto out_free_lu_gp_cache;
114 	}
115 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
116 			sizeof(struct t10_alua_tg_pt_gp),
117 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
118 	if (!t10_alua_tg_pt_gp_cache) {
119 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
120 				"cache failed\n");
121 		goto out_free_lu_gp_mem_cache;
122 	}
123 	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
124 			"t10_alua_tg_pt_gp_mem_cache",
125 			sizeof(struct t10_alua_tg_pt_gp_member),
126 			__alignof__(struct t10_alua_tg_pt_gp_member),
127 			0, NULL);
128 	if (!t10_alua_tg_pt_gp_mem_cache) {
129 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
130 				"mem_t failed\n");
131 		goto out_free_tg_pt_gp_cache;
132 	}
133 	t10_alua_lba_map_cache = kmem_cache_create(
134 			"t10_alua_lba_map_cache",
135 			sizeof(struct t10_alua_lba_map),
136 			__alignof__(struct t10_alua_lba_map), 0, NULL);
137 	if (!t10_alua_lba_map_cache) {
138 		pr_err("kmem_cache_create() for t10_alua_lba_map_"
139 				"cache failed\n");
140 		goto out_free_tg_pt_gp_mem_cache;
141 	}
142 	t10_alua_lba_map_mem_cache = kmem_cache_create(
143 			"t10_alua_lba_map_mem_cache",
144 			sizeof(struct t10_alua_lba_map_member),
145 			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
146 	if (!t10_alua_lba_map_mem_cache) {
147 		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
148 				"cache failed\n");
149 		goto out_free_lba_map_cache;
150 	}
151 
152 	target_completion_wq = alloc_workqueue("target_completion",
153 					       WQ_MEM_RECLAIM, 0);
154 	if (!target_completion_wq)
155 		goto out_free_lba_map_mem_cache;
156 
157 	return 0;
158 
159 out_free_lba_map_mem_cache:
160 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
161 out_free_lba_map_cache:
162 	kmem_cache_destroy(t10_alua_lba_map_cache);
163 out_free_tg_pt_gp_mem_cache:
164 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
165 out_free_tg_pt_gp_cache:
166 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
167 out_free_lu_gp_mem_cache:
168 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
169 out_free_lu_gp_cache:
170 	kmem_cache_destroy(t10_alua_lu_gp_cache);
171 out_free_pr_reg_cache:
172 	kmem_cache_destroy(t10_pr_reg_cache);
173 out_free_ua_cache:
174 	kmem_cache_destroy(se_ua_cache);
175 out_free_sess_cache:
176 	kmem_cache_destroy(se_sess_cache);
177 out:
178 	return -ENOMEM;
179 }
180 
181 void release_se_kmem_caches(void)
182 {
183 	destroy_workqueue(target_completion_wq);
184 	kmem_cache_destroy(se_sess_cache);
185 	kmem_cache_destroy(se_ua_cache);
186 	kmem_cache_destroy(t10_pr_reg_cache);
187 	kmem_cache_destroy(t10_alua_lu_gp_cache);
188 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
189 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
190 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
191 	kmem_cache_destroy(t10_alua_lba_map_cache);
192 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
193 }
194 
195 /* This code ensures unique mib indexes are handed out. */
196 static DEFINE_SPINLOCK(scsi_mib_index_lock);
197 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
198 
199 /*
200  * Allocate a new row index for the entry type specified
201  */
202 u32 scsi_get_new_index(scsi_index_t type)
203 {
204 	u32 new_index;
205 
206 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
207 
208 	spin_lock(&scsi_mib_index_lock);
209 	new_index = ++scsi_mib_index[type];
210 	spin_unlock(&scsi_mib_index_lock);
211 
212 	return new_index;
213 }
214 
215 void transport_subsystem_check_init(void)
216 {
217 	int ret;
218 	static int sub_api_initialized;
219 
220 	if (sub_api_initialized)
221 		return;
222 
223 	ret = request_module("target_core_iblock");
224 	if (ret != 0)
225 		pr_err("Unable to load target_core_iblock\n");
226 
227 	ret = request_module("target_core_file");
228 	if (ret != 0)
229 		pr_err("Unable to load target_core_file\n");
230 
231 	ret = request_module("target_core_pscsi");
232 	if (ret != 0)
233 		pr_err("Unable to load target_core_pscsi\n");
234 
235 	ret = request_module("target_core_user");
236 	if (ret != 0)
237 		pr_err("Unable to load target_core_user\n");
238 
239 	sub_api_initialized = 1;
240 }
241 
242 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
243 {
244 	struct se_session *se_sess;
245 
246 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
247 	if (!se_sess) {
248 		pr_err("Unable to allocate struct se_session from"
249 				" se_sess_cache\n");
250 		return ERR_PTR(-ENOMEM);
251 	}
252 	INIT_LIST_HEAD(&se_sess->sess_list);
253 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
254 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
255 	INIT_LIST_HEAD(&se_sess->sess_wait_list);
256 	spin_lock_init(&se_sess->sess_cmd_lock);
257 	kref_init(&se_sess->sess_kref);
258 	se_sess->sup_prot_ops = sup_prot_ops;
259 
260 	return se_sess;
261 }
262 EXPORT_SYMBOL(transport_init_session);
263 
264 int transport_alloc_session_tags(struct se_session *se_sess,
265 			         unsigned int tag_num, unsigned int tag_size)
266 {
267 	int rc;
268 
269 	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
270 					GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
271 	if (!se_sess->sess_cmd_map) {
272 		se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
273 		if (!se_sess->sess_cmd_map) {
274 			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
275 			return -ENOMEM;
276 		}
277 	}
278 
279 	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
280 	if (rc < 0) {
281 		pr_err("Unable to init se_sess->sess_tag_pool,"
282 			" tag_num: %u\n", tag_num);
283 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
284 			vfree(se_sess->sess_cmd_map);
285 		else
286 			kfree(se_sess->sess_cmd_map);
287 		se_sess->sess_cmd_map = NULL;
288 		return -ENOMEM;
289 	}
290 
291 	return 0;
292 }
293 EXPORT_SYMBOL(transport_alloc_session_tags);
294 
295 struct se_session *transport_init_session_tags(unsigned int tag_num,
296 					       unsigned int tag_size,
297 					       enum target_prot_op sup_prot_ops)
298 {
299 	struct se_session *se_sess;
300 	int rc;
301 
302 	se_sess = transport_init_session(sup_prot_ops);
303 	if (IS_ERR(se_sess))
304 		return se_sess;
305 
306 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
307 	if (rc < 0) {
308 		transport_free_session(se_sess);
309 		return ERR_PTR(-ENOMEM);
310 	}
311 
312 	return se_sess;
313 }
314 EXPORT_SYMBOL(transport_init_session_tags);
315 
316 /*
317  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
318  */
319 void __transport_register_session(
320 	struct se_portal_group *se_tpg,
321 	struct se_node_acl *se_nacl,
322 	struct se_session *se_sess,
323 	void *fabric_sess_ptr)
324 {
325 	unsigned char buf[PR_REG_ISID_LEN];
326 
327 	se_sess->se_tpg = se_tpg;
328 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
329 	/*
330 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
331 	 *
332 	 * Only set for struct se_session's that will actually be moving I/O.
333 	 * eg: *NOT* discovery sessions.
334 	 */
335 	if (se_nacl) {
336 		/*
337 		 * If the fabric module supports an ISID based TransportID,
338 		 * save this value in binary from the fabric I_T Nexus now.
339 		 */
340 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
341 			memset(&buf[0], 0, PR_REG_ISID_LEN);
342 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
343 					&buf[0], PR_REG_ISID_LEN);
344 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
345 		}
346 		kref_get(&se_nacl->acl_kref);
347 
348 		spin_lock_irq(&se_nacl->nacl_sess_lock);
349 		/*
350 		 * The se_nacl->nacl_sess pointer will be set to the
351 		 * last active I_T Nexus for each struct se_node_acl.
352 		 */
353 		se_nacl->nacl_sess = se_sess;
354 
355 		list_add_tail(&se_sess->sess_acl_list,
356 			      &se_nacl->acl_sess_list);
357 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
358 	}
359 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
360 
361 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
362 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
363 }
364 EXPORT_SYMBOL(__transport_register_session);
365 
366 void transport_register_session(
367 	struct se_portal_group *se_tpg,
368 	struct se_node_acl *se_nacl,
369 	struct se_session *se_sess,
370 	void *fabric_sess_ptr)
371 {
372 	unsigned long flags;
373 
374 	spin_lock_irqsave(&se_tpg->session_lock, flags);
375 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
376 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
377 }
378 EXPORT_SYMBOL(transport_register_session);
379 
380 static void target_release_session(struct kref *kref)
381 {
382 	struct se_session *se_sess = container_of(kref,
383 			struct se_session, sess_kref);
384 	struct se_portal_group *se_tpg = se_sess->se_tpg;
385 
386 	se_tpg->se_tpg_tfo->close_session(se_sess);
387 }
388 
389 void target_get_session(struct se_session *se_sess)
390 {
391 	kref_get(&se_sess->sess_kref);
392 }
393 EXPORT_SYMBOL(target_get_session);
394 
395 void target_put_session(struct se_session *se_sess)
396 {
397 	struct se_portal_group *tpg = se_sess->se_tpg;
398 
399 	if (tpg->se_tpg_tfo->put_session != NULL) {
400 		tpg->se_tpg_tfo->put_session(se_sess);
401 		return;
402 	}
403 	kref_put(&se_sess->sess_kref, target_release_session);
404 }
405 EXPORT_SYMBOL(target_put_session);
406 
407 static void target_complete_nacl(struct kref *kref)
408 {
409 	struct se_node_acl *nacl = container_of(kref,
410 				struct se_node_acl, acl_kref);
411 
412 	complete(&nacl->acl_free_comp);
413 }
414 
415 void target_put_nacl(struct se_node_acl *nacl)
416 {
417 	kref_put(&nacl->acl_kref, target_complete_nacl);
418 }
419 
420 void transport_deregister_session_configfs(struct se_session *se_sess)
421 {
422 	struct se_node_acl *se_nacl;
423 	unsigned long flags;
424 	/*
425 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
426 	 */
427 	se_nacl = se_sess->se_node_acl;
428 	if (se_nacl) {
429 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
430 		if (se_nacl->acl_stop == 0)
431 			list_del(&se_sess->sess_acl_list);
432 		/*
433 		 * If the session list is empty, then clear the pointer.
434 		 * Otherwise, set the struct se_session pointer from the tail
435 		 * element of the per struct se_node_acl active session list.
436 		 */
437 		if (list_empty(&se_nacl->acl_sess_list))
438 			se_nacl->nacl_sess = NULL;
439 		else {
440 			se_nacl->nacl_sess = container_of(
441 					se_nacl->acl_sess_list.prev,
442 					struct se_session, sess_acl_list);
443 		}
444 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
445 	}
446 }
447 EXPORT_SYMBOL(transport_deregister_session_configfs);
448 
449 void transport_free_session(struct se_session *se_sess)
450 {
451 	if (se_sess->sess_cmd_map) {
452 		percpu_ida_destroy(&se_sess->sess_tag_pool);
453 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
454 			vfree(se_sess->sess_cmd_map);
455 		else
456 			kfree(se_sess->sess_cmd_map);
457 	}
458 	kmem_cache_free(se_sess_cache, se_sess);
459 }
460 EXPORT_SYMBOL(transport_free_session);
461 
462 void transport_deregister_session(struct se_session *se_sess)
463 {
464 	struct se_portal_group *se_tpg = se_sess->se_tpg;
465 	struct target_core_fabric_ops *se_tfo;
466 	struct se_node_acl *se_nacl;
467 	unsigned long flags;
468 	bool comp_nacl = true;
469 
470 	if (!se_tpg) {
471 		transport_free_session(se_sess);
472 		return;
473 	}
474 	se_tfo = se_tpg->se_tpg_tfo;
475 
476 	spin_lock_irqsave(&se_tpg->session_lock, flags);
477 	list_del(&se_sess->sess_list);
478 	se_sess->se_tpg = NULL;
479 	se_sess->fabric_sess_ptr = NULL;
480 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
481 
482 	/*
483 	 * Determine if we need to do extra work for this initiator node's
484 	 * struct se_node_acl if it had been previously dynamically generated.
485 	 */
486 	se_nacl = se_sess->se_node_acl;
487 
488 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
489 	if (se_nacl && se_nacl->dynamic_node_acl) {
490 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
491 			list_del(&se_nacl->acl_list);
492 			se_tpg->num_node_acls--;
493 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
494 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
495 			core_free_device_list_for_node(se_nacl, se_tpg);
496 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
497 
498 			comp_nacl = false;
499 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
500 		}
501 	}
502 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
503 
504 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
505 		se_tpg->se_tpg_tfo->get_fabric_name());
506 	/*
507 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
508 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
509 	 * removal context.
510 	 */
511 	if (se_nacl && comp_nacl)
512 		target_put_nacl(se_nacl);
513 
514 	transport_free_session(se_sess);
515 }
516 EXPORT_SYMBOL(transport_deregister_session);
517 
518 /*
519  * Called with cmd->t_state_lock held.
520  */
521 static void target_remove_from_state_list(struct se_cmd *cmd)
522 {
523 	struct se_device *dev = cmd->se_dev;
524 	unsigned long flags;
525 
526 	if (!dev)
527 		return;
528 
529 	if (cmd->transport_state & CMD_T_BUSY)
530 		return;
531 
532 	spin_lock_irqsave(&dev->execute_task_lock, flags);
533 	if (cmd->state_active) {
534 		list_del(&cmd->state_list);
535 		cmd->state_active = false;
536 	}
537 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
538 }
539 
540 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
541 				    bool write_pending)
542 {
543 	unsigned long flags;
544 
545 	spin_lock_irqsave(&cmd->t_state_lock, flags);
546 	if (write_pending)
547 		cmd->t_state = TRANSPORT_WRITE_PENDING;
548 
549 	if (remove_from_lists) {
550 		target_remove_from_state_list(cmd);
551 
552 		/*
553 		 * Clear struct se_cmd->se_lun before the handoff to FE.
554 		 */
555 		cmd->se_lun = NULL;
556 	}
557 
558 	/*
559 	 * Determine if frontend context caller is requesting the stopping of
560 	 * this command for frontend exceptions.
561 	 */
562 	if (cmd->transport_state & CMD_T_STOP) {
563 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
564 			__func__, __LINE__,
565 			cmd->se_tfo->get_task_tag(cmd));
566 
567 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
568 
569 		complete_all(&cmd->t_transport_stop_comp);
570 		return 1;
571 	}
572 
573 	cmd->transport_state &= ~CMD_T_ACTIVE;
574 	if (remove_from_lists) {
575 		/*
576 		 * Some fabric modules like tcm_loop can release
577 		 * their internally allocated I/O reference now and
578 		 * struct se_cmd now.
579 		 *
580 		 * Fabric modules are expected to return '1' here if the
581 		 * se_cmd being passed is released at this point,
582 		 * or zero if not being released.
583 		 */
584 		if (cmd->se_tfo->check_stop_free != NULL) {
585 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
586 			return cmd->se_tfo->check_stop_free(cmd);
587 		}
588 	}
589 
590 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
591 	return 0;
592 }
593 
594 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
595 {
596 	return transport_cmd_check_stop(cmd, true, false);
597 }
598 
599 static void transport_lun_remove_cmd(struct se_cmd *cmd)
600 {
601 	struct se_lun *lun = cmd->se_lun;
602 
603 	if (!lun)
604 		return;
605 
606 	if (cmpxchg(&cmd->lun_ref_active, true, false))
607 		percpu_ref_put(&lun->lun_ref);
608 }
609 
610 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
611 {
612 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
613 		transport_lun_remove_cmd(cmd);
614 	/*
615 	 * Allow the fabric driver to unmap any resources before
616 	 * releasing the descriptor via TFO->release_cmd()
617 	 */
618 	if (remove)
619 		cmd->se_tfo->aborted_task(cmd);
620 
621 	if (transport_cmd_check_stop_to_fabric(cmd))
622 		return;
623 	if (remove)
624 		transport_put_cmd(cmd);
625 }
626 
627 static void target_complete_failure_work(struct work_struct *work)
628 {
629 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
630 
631 	transport_generic_request_failure(cmd,
632 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
633 }
634 
635 /*
636  * Used when asking transport to copy Sense Data from the underlying
637  * Linux/SCSI struct scsi_cmnd
638  */
639 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
640 {
641 	struct se_device *dev = cmd->se_dev;
642 
643 	WARN_ON(!cmd->se_lun);
644 
645 	if (!dev)
646 		return NULL;
647 
648 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
649 		return NULL;
650 
651 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
652 
653 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
654 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
655 	return cmd->sense_buffer;
656 }
657 
658 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
659 {
660 	struct se_device *dev = cmd->se_dev;
661 	int success = scsi_status == GOOD;
662 	unsigned long flags;
663 
664 	cmd->scsi_status = scsi_status;
665 
666 
667 	spin_lock_irqsave(&cmd->t_state_lock, flags);
668 	cmd->transport_state &= ~CMD_T_BUSY;
669 
670 	if (dev && dev->transport->transport_complete) {
671 		dev->transport->transport_complete(cmd,
672 				cmd->t_data_sg,
673 				transport_get_sense_buffer(cmd));
674 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
675 			success = 1;
676 	}
677 
678 	/*
679 	 * See if we are waiting to complete for an exception condition.
680 	 */
681 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
682 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
683 		complete(&cmd->task_stop_comp);
684 		return;
685 	}
686 
687 	/*
688 	 * Check for case where an explicit ABORT_TASK has been received
689 	 * and transport_wait_for_tasks() will be waiting for completion..
690 	 */
691 	if (cmd->transport_state & CMD_T_ABORTED &&
692 	    cmd->transport_state & CMD_T_STOP) {
693 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
694 		complete_all(&cmd->t_transport_stop_comp);
695 		return;
696 	} else if (!success) {
697 		INIT_WORK(&cmd->work, target_complete_failure_work);
698 	} else {
699 		INIT_WORK(&cmd->work, target_complete_ok_work);
700 	}
701 
702 	cmd->t_state = TRANSPORT_COMPLETE;
703 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
704 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
705 
706 	queue_work(target_completion_wq, &cmd->work);
707 }
708 EXPORT_SYMBOL(target_complete_cmd);
709 
710 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
711 {
712 	if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
713 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
714 			cmd->residual_count += cmd->data_length - length;
715 		} else {
716 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
717 			cmd->residual_count = cmd->data_length - length;
718 		}
719 
720 		cmd->data_length = length;
721 	}
722 
723 	target_complete_cmd(cmd, scsi_status);
724 }
725 EXPORT_SYMBOL(target_complete_cmd_with_length);
726 
727 static void target_add_to_state_list(struct se_cmd *cmd)
728 {
729 	struct se_device *dev = cmd->se_dev;
730 	unsigned long flags;
731 
732 	spin_lock_irqsave(&dev->execute_task_lock, flags);
733 	if (!cmd->state_active) {
734 		list_add_tail(&cmd->state_list, &dev->state_list);
735 		cmd->state_active = true;
736 	}
737 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
738 }
739 
740 /*
741  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
742  */
743 static void transport_write_pending_qf(struct se_cmd *cmd);
744 static void transport_complete_qf(struct se_cmd *cmd);
745 
746 void target_qf_do_work(struct work_struct *work)
747 {
748 	struct se_device *dev = container_of(work, struct se_device,
749 					qf_work_queue);
750 	LIST_HEAD(qf_cmd_list);
751 	struct se_cmd *cmd, *cmd_tmp;
752 
753 	spin_lock_irq(&dev->qf_cmd_lock);
754 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
755 	spin_unlock_irq(&dev->qf_cmd_lock);
756 
757 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
758 		list_del(&cmd->se_qf_node);
759 		atomic_dec_mb(&dev->dev_qf_count);
760 
761 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
762 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
763 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
764 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
765 			: "UNKNOWN");
766 
767 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
768 			transport_write_pending_qf(cmd);
769 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
770 			transport_complete_qf(cmd);
771 	}
772 }
773 
774 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
775 {
776 	switch (cmd->data_direction) {
777 	case DMA_NONE:
778 		return "NONE";
779 	case DMA_FROM_DEVICE:
780 		return "READ";
781 	case DMA_TO_DEVICE:
782 		return "WRITE";
783 	case DMA_BIDIRECTIONAL:
784 		return "BIDI";
785 	default:
786 		break;
787 	}
788 
789 	return "UNKNOWN";
790 }
791 
792 void transport_dump_dev_state(
793 	struct se_device *dev,
794 	char *b,
795 	int *bl)
796 {
797 	*bl += sprintf(b + *bl, "Status: ");
798 	if (dev->export_count)
799 		*bl += sprintf(b + *bl, "ACTIVATED");
800 	else
801 		*bl += sprintf(b + *bl, "DEACTIVATED");
802 
803 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
804 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
805 		dev->dev_attrib.block_size,
806 		dev->dev_attrib.hw_max_sectors);
807 	*bl += sprintf(b + *bl, "        ");
808 }
809 
810 void transport_dump_vpd_proto_id(
811 	struct t10_vpd *vpd,
812 	unsigned char *p_buf,
813 	int p_buf_len)
814 {
815 	unsigned char buf[VPD_TMP_BUF_SIZE];
816 	int len;
817 
818 	memset(buf, 0, VPD_TMP_BUF_SIZE);
819 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
820 
821 	switch (vpd->protocol_identifier) {
822 	case 0x00:
823 		sprintf(buf+len, "Fibre Channel\n");
824 		break;
825 	case 0x10:
826 		sprintf(buf+len, "Parallel SCSI\n");
827 		break;
828 	case 0x20:
829 		sprintf(buf+len, "SSA\n");
830 		break;
831 	case 0x30:
832 		sprintf(buf+len, "IEEE 1394\n");
833 		break;
834 	case 0x40:
835 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
836 				" Protocol\n");
837 		break;
838 	case 0x50:
839 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
840 		break;
841 	case 0x60:
842 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
843 		break;
844 	case 0x70:
845 		sprintf(buf+len, "Automation/Drive Interface Transport"
846 				" Protocol\n");
847 		break;
848 	case 0x80:
849 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
850 		break;
851 	default:
852 		sprintf(buf+len, "Unknown 0x%02x\n",
853 				vpd->protocol_identifier);
854 		break;
855 	}
856 
857 	if (p_buf)
858 		strncpy(p_buf, buf, p_buf_len);
859 	else
860 		pr_debug("%s", buf);
861 }
862 
863 void
864 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
865 {
866 	/*
867 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
868 	 *
869 	 * from spc3r23.pdf section 7.5.1
870 	 */
871 	 if (page_83[1] & 0x80) {
872 		vpd->protocol_identifier = (page_83[0] & 0xf0);
873 		vpd->protocol_identifier_set = 1;
874 		transport_dump_vpd_proto_id(vpd, NULL, 0);
875 	}
876 }
877 EXPORT_SYMBOL(transport_set_vpd_proto_id);
878 
879 int transport_dump_vpd_assoc(
880 	struct t10_vpd *vpd,
881 	unsigned char *p_buf,
882 	int p_buf_len)
883 {
884 	unsigned char buf[VPD_TMP_BUF_SIZE];
885 	int ret = 0;
886 	int len;
887 
888 	memset(buf, 0, VPD_TMP_BUF_SIZE);
889 	len = sprintf(buf, "T10 VPD Identifier Association: ");
890 
891 	switch (vpd->association) {
892 	case 0x00:
893 		sprintf(buf+len, "addressed logical unit\n");
894 		break;
895 	case 0x10:
896 		sprintf(buf+len, "target port\n");
897 		break;
898 	case 0x20:
899 		sprintf(buf+len, "SCSI target device\n");
900 		break;
901 	default:
902 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
903 		ret = -EINVAL;
904 		break;
905 	}
906 
907 	if (p_buf)
908 		strncpy(p_buf, buf, p_buf_len);
909 	else
910 		pr_debug("%s", buf);
911 
912 	return ret;
913 }
914 
915 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
916 {
917 	/*
918 	 * The VPD identification association..
919 	 *
920 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
921 	 */
922 	vpd->association = (page_83[1] & 0x30);
923 	return transport_dump_vpd_assoc(vpd, NULL, 0);
924 }
925 EXPORT_SYMBOL(transport_set_vpd_assoc);
926 
927 int transport_dump_vpd_ident_type(
928 	struct t10_vpd *vpd,
929 	unsigned char *p_buf,
930 	int p_buf_len)
931 {
932 	unsigned char buf[VPD_TMP_BUF_SIZE];
933 	int ret = 0;
934 	int len;
935 
936 	memset(buf, 0, VPD_TMP_BUF_SIZE);
937 	len = sprintf(buf, "T10 VPD Identifier Type: ");
938 
939 	switch (vpd->device_identifier_type) {
940 	case 0x00:
941 		sprintf(buf+len, "Vendor specific\n");
942 		break;
943 	case 0x01:
944 		sprintf(buf+len, "T10 Vendor ID based\n");
945 		break;
946 	case 0x02:
947 		sprintf(buf+len, "EUI-64 based\n");
948 		break;
949 	case 0x03:
950 		sprintf(buf+len, "NAA\n");
951 		break;
952 	case 0x04:
953 		sprintf(buf+len, "Relative target port identifier\n");
954 		break;
955 	case 0x08:
956 		sprintf(buf+len, "SCSI name string\n");
957 		break;
958 	default:
959 		sprintf(buf+len, "Unsupported: 0x%02x\n",
960 				vpd->device_identifier_type);
961 		ret = -EINVAL;
962 		break;
963 	}
964 
965 	if (p_buf) {
966 		if (p_buf_len < strlen(buf)+1)
967 			return -EINVAL;
968 		strncpy(p_buf, buf, p_buf_len);
969 	} else {
970 		pr_debug("%s", buf);
971 	}
972 
973 	return ret;
974 }
975 
976 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
977 {
978 	/*
979 	 * The VPD identifier type..
980 	 *
981 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
982 	 */
983 	vpd->device_identifier_type = (page_83[1] & 0x0f);
984 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
985 }
986 EXPORT_SYMBOL(transport_set_vpd_ident_type);
987 
988 int transport_dump_vpd_ident(
989 	struct t10_vpd *vpd,
990 	unsigned char *p_buf,
991 	int p_buf_len)
992 {
993 	unsigned char buf[VPD_TMP_BUF_SIZE];
994 	int ret = 0;
995 
996 	memset(buf, 0, VPD_TMP_BUF_SIZE);
997 
998 	switch (vpd->device_identifier_code_set) {
999 	case 0x01: /* Binary */
1000 		snprintf(buf, sizeof(buf),
1001 			"T10 VPD Binary Device Identifier: %s\n",
1002 			&vpd->device_identifier[0]);
1003 		break;
1004 	case 0x02: /* ASCII */
1005 		snprintf(buf, sizeof(buf),
1006 			"T10 VPD ASCII Device Identifier: %s\n",
1007 			&vpd->device_identifier[0]);
1008 		break;
1009 	case 0x03: /* UTF-8 */
1010 		snprintf(buf, sizeof(buf),
1011 			"T10 VPD UTF-8 Device Identifier: %s\n",
1012 			&vpd->device_identifier[0]);
1013 		break;
1014 	default:
1015 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1016 			" 0x%02x", vpd->device_identifier_code_set);
1017 		ret = -EINVAL;
1018 		break;
1019 	}
1020 
1021 	if (p_buf)
1022 		strncpy(p_buf, buf, p_buf_len);
1023 	else
1024 		pr_debug("%s", buf);
1025 
1026 	return ret;
1027 }
1028 
1029 int
1030 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1031 {
1032 	static const char hex_str[] = "0123456789abcdef";
1033 	int j = 0, i = 4; /* offset to start of the identifier */
1034 
1035 	/*
1036 	 * The VPD Code Set (encoding)
1037 	 *
1038 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1039 	 */
1040 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1041 	switch (vpd->device_identifier_code_set) {
1042 	case 0x01: /* Binary */
1043 		vpd->device_identifier[j++] =
1044 				hex_str[vpd->device_identifier_type];
1045 		while (i < (4 + page_83[3])) {
1046 			vpd->device_identifier[j++] =
1047 				hex_str[(page_83[i] & 0xf0) >> 4];
1048 			vpd->device_identifier[j++] =
1049 				hex_str[page_83[i] & 0x0f];
1050 			i++;
1051 		}
1052 		break;
1053 	case 0x02: /* ASCII */
1054 	case 0x03: /* UTF-8 */
1055 		while (i < (4 + page_83[3]))
1056 			vpd->device_identifier[j++] = page_83[i++];
1057 		break;
1058 	default:
1059 		break;
1060 	}
1061 
1062 	return transport_dump_vpd_ident(vpd, NULL, 0);
1063 }
1064 EXPORT_SYMBOL(transport_set_vpd_ident);
1065 
1066 sense_reason_t
1067 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1068 {
1069 	struct se_device *dev = cmd->se_dev;
1070 
1071 	if (cmd->unknown_data_length) {
1072 		cmd->data_length = size;
1073 	} else if (size != cmd->data_length) {
1074 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1075 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1076 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1077 				cmd->data_length, size, cmd->t_task_cdb[0]);
1078 
1079 		if (cmd->data_direction == DMA_TO_DEVICE) {
1080 			pr_err("Rejecting underflow/overflow"
1081 					" WRITE data\n");
1082 			return TCM_INVALID_CDB_FIELD;
1083 		}
1084 		/*
1085 		 * Reject READ_* or WRITE_* with overflow/underflow for
1086 		 * type SCF_SCSI_DATA_CDB.
1087 		 */
1088 		if (dev->dev_attrib.block_size != 512)  {
1089 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1090 				" CDB on non 512-byte sector setup subsystem"
1091 				" plugin: %s\n", dev->transport->name);
1092 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1093 			return TCM_INVALID_CDB_FIELD;
1094 		}
1095 		/*
1096 		 * For the overflow case keep the existing fabric provided
1097 		 * ->data_length.  Otherwise for the underflow case, reset
1098 		 * ->data_length to the smaller SCSI expected data transfer
1099 		 * length.
1100 		 */
1101 		if (size > cmd->data_length) {
1102 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1103 			cmd->residual_count = (size - cmd->data_length);
1104 		} else {
1105 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1106 			cmd->residual_count = (cmd->data_length - size);
1107 			cmd->data_length = size;
1108 		}
1109 	}
1110 
1111 	return 0;
1112 
1113 }
1114 
1115 /*
1116  * Used by fabric modules containing a local struct se_cmd within their
1117  * fabric dependent per I/O descriptor.
1118  */
1119 void transport_init_se_cmd(
1120 	struct se_cmd *cmd,
1121 	struct target_core_fabric_ops *tfo,
1122 	struct se_session *se_sess,
1123 	u32 data_length,
1124 	int data_direction,
1125 	int task_attr,
1126 	unsigned char *sense_buffer)
1127 {
1128 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1129 	INIT_LIST_HEAD(&cmd->se_qf_node);
1130 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1131 	INIT_LIST_HEAD(&cmd->state_list);
1132 	init_completion(&cmd->t_transport_stop_comp);
1133 	init_completion(&cmd->cmd_wait_comp);
1134 	init_completion(&cmd->task_stop_comp);
1135 	spin_lock_init(&cmd->t_state_lock);
1136 	kref_init(&cmd->cmd_kref);
1137 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1138 
1139 	cmd->se_tfo = tfo;
1140 	cmd->se_sess = se_sess;
1141 	cmd->data_length = data_length;
1142 	cmd->data_direction = data_direction;
1143 	cmd->sam_task_attr = task_attr;
1144 	cmd->sense_buffer = sense_buffer;
1145 
1146 	cmd->state_active = false;
1147 }
1148 EXPORT_SYMBOL(transport_init_se_cmd);
1149 
1150 static sense_reason_t
1151 transport_check_alloc_task_attr(struct se_cmd *cmd)
1152 {
1153 	struct se_device *dev = cmd->se_dev;
1154 
1155 	/*
1156 	 * Check if SAM Task Attribute emulation is enabled for this
1157 	 * struct se_device storage object
1158 	 */
1159 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1160 		return 0;
1161 
1162 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1163 		pr_debug("SAM Task Attribute ACA"
1164 			" emulation is not supported\n");
1165 		return TCM_INVALID_CDB_FIELD;
1166 	}
1167 	/*
1168 	 * Used to determine when ORDERED commands should go from
1169 	 * Dormant to Active status.
1170 	 */
1171 	cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1172 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1173 			cmd->se_ordered_id, cmd->sam_task_attr,
1174 			dev->transport->name);
1175 	return 0;
1176 }
1177 
1178 sense_reason_t
1179 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1180 {
1181 	struct se_device *dev = cmd->se_dev;
1182 	sense_reason_t ret;
1183 
1184 	/*
1185 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1186 	 * for VARIABLE_LENGTH_CMD
1187 	 */
1188 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1189 		pr_err("Received SCSI CDB with command_size: %d that"
1190 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1191 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1192 		return TCM_INVALID_CDB_FIELD;
1193 	}
1194 	/*
1195 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1196 	 * allocate the additional extended CDB buffer now..  Otherwise
1197 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1198 	 */
1199 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1200 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1201 						GFP_KERNEL);
1202 		if (!cmd->t_task_cdb) {
1203 			pr_err("Unable to allocate cmd->t_task_cdb"
1204 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1205 				scsi_command_size(cdb),
1206 				(unsigned long)sizeof(cmd->__t_task_cdb));
1207 			return TCM_OUT_OF_RESOURCES;
1208 		}
1209 	} else
1210 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1211 	/*
1212 	 * Copy the original CDB into cmd->
1213 	 */
1214 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1215 
1216 	trace_target_sequencer_start(cmd);
1217 
1218 	/*
1219 	 * Check for an existing UNIT ATTENTION condition
1220 	 */
1221 	ret = target_scsi3_ua_check(cmd);
1222 	if (ret)
1223 		return ret;
1224 
1225 	ret = target_alua_state_check(cmd);
1226 	if (ret)
1227 		return ret;
1228 
1229 	ret = target_check_reservation(cmd);
1230 	if (ret) {
1231 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1232 		return ret;
1233 	}
1234 
1235 	ret = dev->transport->parse_cdb(cmd);
1236 	if (ret)
1237 		return ret;
1238 
1239 	ret = transport_check_alloc_task_attr(cmd);
1240 	if (ret)
1241 		return ret;
1242 
1243 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1244 
1245 	spin_lock(&cmd->se_lun->lun_sep_lock);
1246 	if (cmd->se_lun->lun_sep)
1247 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1248 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1249 	return 0;
1250 }
1251 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1252 
1253 /*
1254  * Used by fabric module frontends to queue tasks directly.
1255  * Many only be used from process context only
1256  */
1257 int transport_handle_cdb_direct(
1258 	struct se_cmd *cmd)
1259 {
1260 	sense_reason_t ret;
1261 
1262 	if (!cmd->se_lun) {
1263 		dump_stack();
1264 		pr_err("cmd->se_lun is NULL\n");
1265 		return -EINVAL;
1266 	}
1267 	if (in_interrupt()) {
1268 		dump_stack();
1269 		pr_err("transport_generic_handle_cdb cannot be called"
1270 				" from interrupt context\n");
1271 		return -EINVAL;
1272 	}
1273 	/*
1274 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1275 	 * outstanding descriptors are handled correctly during shutdown via
1276 	 * transport_wait_for_tasks()
1277 	 *
1278 	 * Also, we don't take cmd->t_state_lock here as we only expect
1279 	 * this to be called for initial descriptor submission.
1280 	 */
1281 	cmd->t_state = TRANSPORT_NEW_CMD;
1282 	cmd->transport_state |= CMD_T_ACTIVE;
1283 
1284 	/*
1285 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1286 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1287 	 * and call transport_generic_request_failure() if necessary..
1288 	 */
1289 	ret = transport_generic_new_cmd(cmd);
1290 	if (ret)
1291 		transport_generic_request_failure(cmd, ret);
1292 	return 0;
1293 }
1294 EXPORT_SYMBOL(transport_handle_cdb_direct);
1295 
1296 sense_reason_t
1297 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1298 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1299 {
1300 	if (!sgl || !sgl_count)
1301 		return 0;
1302 
1303 	/*
1304 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1305 	 * scatterlists already have been set to follow what the fabric
1306 	 * passes for the original expected data transfer length.
1307 	 */
1308 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1309 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1310 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1311 		return TCM_INVALID_CDB_FIELD;
1312 	}
1313 
1314 	cmd->t_data_sg = sgl;
1315 	cmd->t_data_nents = sgl_count;
1316 
1317 	if (sgl_bidi && sgl_bidi_count) {
1318 		cmd->t_bidi_data_sg = sgl_bidi;
1319 		cmd->t_bidi_data_nents = sgl_bidi_count;
1320 	}
1321 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1322 	return 0;
1323 }
1324 
1325 /*
1326  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1327  * 			 se_cmd + use pre-allocated SGL memory.
1328  *
1329  * @se_cmd: command descriptor to submit
1330  * @se_sess: associated se_sess for endpoint
1331  * @cdb: pointer to SCSI CDB
1332  * @sense: pointer to SCSI sense buffer
1333  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1334  * @data_length: fabric expected data transfer length
1335  * @task_addr: SAM task attribute
1336  * @data_dir: DMA data direction
1337  * @flags: flags for command submission from target_sc_flags_tables
1338  * @sgl: struct scatterlist memory for unidirectional mapping
1339  * @sgl_count: scatterlist count for unidirectional mapping
1340  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1341  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1342  * @sgl_prot: struct scatterlist memory protection information
1343  * @sgl_prot_count: scatterlist count for protection information
1344  *
1345  * Returns non zero to signal active I/O shutdown failure.  All other
1346  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1347  * but still return zero here.
1348  *
1349  * This may only be called from process context, and also currently
1350  * assumes internal allocation of fabric payload buffer by target-core.
1351  */
1352 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1353 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1354 		u32 data_length, int task_attr, int data_dir, int flags,
1355 		struct scatterlist *sgl, u32 sgl_count,
1356 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1357 		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1358 {
1359 	struct se_portal_group *se_tpg;
1360 	sense_reason_t rc;
1361 	int ret;
1362 
1363 	se_tpg = se_sess->se_tpg;
1364 	BUG_ON(!se_tpg);
1365 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1366 	BUG_ON(in_interrupt());
1367 	/*
1368 	 * Initialize se_cmd for target operation.  From this point
1369 	 * exceptions are handled by sending exception status via
1370 	 * target_core_fabric_ops->queue_status() callback
1371 	 */
1372 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1373 				data_length, data_dir, task_attr, sense);
1374 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1375 		se_cmd->unknown_data_length = 1;
1376 	/*
1377 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1378 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1379 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1380 	 * kref_put() to happen during fabric packet acknowledgement.
1381 	 */
1382 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1383 	if (ret)
1384 		return ret;
1385 	/*
1386 	 * Signal bidirectional data payloads to target-core
1387 	 */
1388 	if (flags & TARGET_SCF_BIDI_OP)
1389 		se_cmd->se_cmd_flags |= SCF_BIDI;
1390 	/*
1391 	 * Locate se_lun pointer and attach it to struct se_cmd
1392 	 */
1393 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1394 	if (rc) {
1395 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1396 		target_put_sess_cmd(se_sess, se_cmd);
1397 		return 0;
1398 	}
1399 
1400 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1401 	if (rc != 0) {
1402 		transport_generic_request_failure(se_cmd, rc);
1403 		return 0;
1404 	}
1405 
1406 	/*
1407 	 * Save pointers for SGLs containing protection information,
1408 	 * if present.
1409 	 */
1410 	if (sgl_prot_count) {
1411 		se_cmd->t_prot_sg = sgl_prot;
1412 		se_cmd->t_prot_nents = sgl_prot_count;
1413 	}
1414 
1415 	/*
1416 	 * When a non zero sgl_count has been passed perform SGL passthrough
1417 	 * mapping for pre-allocated fabric memory instead of having target
1418 	 * core perform an internal SGL allocation..
1419 	 */
1420 	if (sgl_count != 0) {
1421 		BUG_ON(!sgl);
1422 
1423 		/*
1424 		 * A work-around for tcm_loop as some userspace code via
1425 		 * scsi-generic do not memset their associated read buffers,
1426 		 * so go ahead and do that here for type non-data CDBs.  Also
1427 		 * note that this is currently guaranteed to be a single SGL
1428 		 * for this case by target core in target_setup_cmd_from_cdb()
1429 		 * -> transport_generic_cmd_sequencer().
1430 		 */
1431 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1432 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1433 			unsigned char *buf = NULL;
1434 
1435 			if (sgl)
1436 				buf = kmap(sg_page(sgl)) + sgl->offset;
1437 
1438 			if (buf) {
1439 				memset(buf, 0, sgl->length);
1440 				kunmap(sg_page(sgl));
1441 			}
1442 		}
1443 
1444 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1445 				sgl_bidi, sgl_bidi_count);
1446 		if (rc != 0) {
1447 			transport_generic_request_failure(se_cmd, rc);
1448 			return 0;
1449 		}
1450 	}
1451 
1452 	/*
1453 	 * Check if we need to delay processing because of ALUA
1454 	 * Active/NonOptimized primary access state..
1455 	 */
1456 	core_alua_check_nonop_delay(se_cmd);
1457 
1458 	transport_handle_cdb_direct(se_cmd);
1459 	return 0;
1460 }
1461 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1462 
1463 /*
1464  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1465  *
1466  * @se_cmd: command descriptor to submit
1467  * @se_sess: associated se_sess for endpoint
1468  * @cdb: pointer to SCSI CDB
1469  * @sense: pointer to SCSI sense buffer
1470  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1471  * @data_length: fabric expected data transfer length
1472  * @task_addr: SAM task attribute
1473  * @data_dir: DMA data direction
1474  * @flags: flags for command submission from target_sc_flags_tables
1475  *
1476  * Returns non zero to signal active I/O shutdown failure.  All other
1477  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1478  * but still return zero here.
1479  *
1480  * This may only be called from process context, and also currently
1481  * assumes internal allocation of fabric payload buffer by target-core.
1482  *
1483  * It also assumes interal target core SGL memory allocation.
1484  */
1485 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1486 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1487 		u32 data_length, int task_attr, int data_dir, int flags)
1488 {
1489 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1490 			unpacked_lun, data_length, task_attr, data_dir,
1491 			flags, NULL, 0, NULL, 0, NULL, 0);
1492 }
1493 EXPORT_SYMBOL(target_submit_cmd);
1494 
1495 static void target_complete_tmr_failure(struct work_struct *work)
1496 {
1497 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1498 
1499 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1500 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1501 
1502 	transport_cmd_check_stop_to_fabric(se_cmd);
1503 }
1504 
1505 /**
1506  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1507  *                     for TMR CDBs
1508  *
1509  * @se_cmd: command descriptor to submit
1510  * @se_sess: associated se_sess for endpoint
1511  * @sense: pointer to SCSI sense buffer
1512  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1513  * @fabric_context: fabric context for TMR req
1514  * @tm_type: Type of TM request
1515  * @gfp: gfp type for caller
1516  * @tag: referenced task tag for TMR_ABORT_TASK
1517  * @flags: submit cmd flags
1518  *
1519  * Callable from all contexts.
1520  **/
1521 
1522 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1523 		unsigned char *sense, u32 unpacked_lun,
1524 		void *fabric_tmr_ptr, unsigned char tm_type,
1525 		gfp_t gfp, unsigned int tag, int flags)
1526 {
1527 	struct se_portal_group *se_tpg;
1528 	int ret;
1529 
1530 	se_tpg = se_sess->se_tpg;
1531 	BUG_ON(!se_tpg);
1532 
1533 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1534 			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1535 	/*
1536 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1537 	 * allocation failure.
1538 	 */
1539 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1540 	if (ret < 0)
1541 		return -ENOMEM;
1542 
1543 	if (tm_type == TMR_ABORT_TASK)
1544 		se_cmd->se_tmr_req->ref_task_tag = tag;
1545 
1546 	/* See target_submit_cmd for commentary */
1547 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1548 	if (ret) {
1549 		core_tmr_release_req(se_cmd->se_tmr_req);
1550 		return ret;
1551 	}
1552 
1553 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1554 	if (ret) {
1555 		/*
1556 		 * For callback during failure handling, push this work off
1557 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1558 		 */
1559 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1560 		schedule_work(&se_cmd->work);
1561 		return 0;
1562 	}
1563 	transport_generic_handle_tmr(se_cmd);
1564 	return 0;
1565 }
1566 EXPORT_SYMBOL(target_submit_tmr);
1567 
1568 /*
1569  * If the cmd is active, request it to be stopped and sleep until it
1570  * has completed.
1571  */
1572 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1573 {
1574 	bool was_active = false;
1575 
1576 	if (cmd->transport_state & CMD_T_BUSY) {
1577 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1578 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1579 
1580 		pr_debug("cmd %p waiting to complete\n", cmd);
1581 		wait_for_completion(&cmd->task_stop_comp);
1582 		pr_debug("cmd %p stopped successfully\n", cmd);
1583 
1584 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1585 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1586 		cmd->transport_state &= ~CMD_T_BUSY;
1587 		was_active = true;
1588 	}
1589 
1590 	return was_active;
1591 }
1592 
1593 /*
1594  * Handle SAM-esque emulation for generic transport request failures.
1595  */
1596 void transport_generic_request_failure(struct se_cmd *cmd,
1597 		sense_reason_t sense_reason)
1598 {
1599 	int ret = 0;
1600 
1601 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1602 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1603 		cmd->t_task_cdb[0]);
1604 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1605 		cmd->se_tfo->get_cmd_state(cmd),
1606 		cmd->t_state, sense_reason);
1607 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1608 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1609 		(cmd->transport_state & CMD_T_STOP) != 0,
1610 		(cmd->transport_state & CMD_T_SENT) != 0);
1611 
1612 	/*
1613 	 * For SAM Task Attribute emulation for failed struct se_cmd
1614 	 */
1615 	transport_complete_task_attr(cmd);
1616 	/*
1617 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1618 	 * callback is expected to drop the per device ->caw_mutex.
1619 	 */
1620 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1621 	     cmd->transport_complete_callback)
1622 		cmd->transport_complete_callback(cmd);
1623 
1624 	switch (sense_reason) {
1625 	case TCM_NON_EXISTENT_LUN:
1626 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1627 	case TCM_INVALID_CDB_FIELD:
1628 	case TCM_INVALID_PARAMETER_LIST:
1629 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1630 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1631 	case TCM_UNKNOWN_MODE_PAGE:
1632 	case TCM_WRITE_PROTECTED:
1633 	case TCM_ADDRESS_OUT_OF_RANGE:
1634 	case TCM_CHECK_CONDITION_ABORT_CMD:
1635 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1636 	case TCM_CHECK_CONDITION_NOT_READY:
1637 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1638 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1639 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1640 		break;
1641 	case TCM_OUT_OF_RESOURCES:
1642 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1643 		break;
1644 	case TCM_RESERVATION_CONFLICT:
1645 		/*
1646 		 * No SENSE Data payload for this case, set SCSI Status
1647 		 * and queue the response to $FABRIC_MOD.
1648 		 *
1649 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1650 		 */
1651 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1652 		/*
1653 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1654 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1655 		 * CONFLICT STATUS.
1656 		 *
1657 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1658 		 */
1659 		if (cmd->se_sess &&
1660 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1661 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1662 				cmd->orig_fe_lun, 0x2C,
1663 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1664 
1665 		trace_target_cmd_complete(cmd);
1666 		ret = cmd->se_tfo-> queue_status(cmd);
1667 		if (ret == -EAGAIN || ret == -ENOMEM)
1668 			goto queue_full;
1669 		goto check_stop;
1670 	default:
1671 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1672 			cmd->t_task_cdb[0], sense_reason);
1673 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1674 		break;
1675 	}
1676 
1677 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1678 	if (ret == -EAGAIN || ret == -ENOMEM)
1679 		goto queue_full;
1680 
1681 check_stop:
1682 	transport_lun_remove_cmd(cmd);
1683 	if (!transport_cmd_check_stop_to_fabric(cmd))
1684 		;
1685 	return;
1686 
1687 queue_full:
1688 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1689 	transport_handle_queue_full(cmd, cmd->se_dev);
1690 }
1691 EXPORT_SYMBOL(transport_generic_request_failure);
1692 
1693 void __target_execute_cmd(struct se_cmd *cmd)
1694 {
1695 	sense_reason_t ret;
1696 
1697 	if (cmd->execute_cmd) {
1698 		ret = cmd->execute_cmd(cmd);
1699 		if (ret) {
1700 			spin_lock_irq(&cmd->t_state_lock);
1701 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1702 			spin_unlock_irq(&cmd->t_state_lock);
1703 
1704 			transport_generic_request_failure(cmd, ret);
1705 		}
1706 	}
1707 }
1708 
1709 static bool target_handle_task_attr(struct se_cmd *cmd)
1710 {
1711 	struct se_device *dev = cmd->se_dev;
1712 
1713 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1714 		return false;
1715 
1716 	/*
1717 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1718 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1719 	 */
1720 	switch (cmd->sam_task_attr) {
1721 	case TCM_HEAD_TAG:
1722 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1723 			 "se_ordered_id: %u\n",
1724 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1725 		return false;
1726 	case TCM_ORDERED_TAG:
1727 		atomic_inc_mb(&dev->dev_ordered_sync);
1728 
1729 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1730 			 " se_ordered_id: %u\n",
1731 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1732 
1733 		/*
1734 		 * Execute an ORDERED command if no other older commands
1735 		 * exist that need to be completed first.
1736 		 */
1737 		if (!atomic_read(&dev->simple_cmds))
1738 			return false;
1739 		break;
1740 	default:
1741 		/*
1742 		 * For SIMPLE and UNTAGGED Task Attribute commands
1743 		 */
1744 		atomic_inc_mb(&dev->simple_cmds);
1745 		break;
1746 	}
1747 
1748 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1749 		return false;
1750 
1751 	spin_lock(&dev->delayed_cmd_lock);
1752 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1753 	spin_unlock(&dev->delayed_cmd_lock);
1754 
1755 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1756 		" delayed CMD list, se_ordered_id: %u\n",
1757 		cmd->t_task_cdb[0], cmd->sam_task_attr,
1758 		cmd->se_ordered_id);
1759 	return true;
1760 }
1761 
1762 void target_execute_cmd(struct se_cmd *cmd)
1763 {
1764 	/*
1765 	 * If the received CDB has aleady been aborted stop processing it here.
1766 	 */
1767 	if (transport_check_aborted_status(cmd, 1))
1768 		return;
1769 
1770 	/*
1771 	 * Determine if frontend context caller is requesting the stopping of
1772 	 * this command for frontend exceptions.
1773 	 */
1774 	spin_lock_irq(&cmd->t_state_lock);
1775 	if (cmd->transport_state & CMD_T_STOP) {
1776 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1777 			__func__, __LINE__,
1778 			cmd->se_tfo->get_task_tag(cmd));
1779 
1780 		spin_unlock_irq(&cmd->t_state_lock);
1781 		complete_all(&cmd->t_transport_stop_comp);
1782 		return;
1783 	}
1784 
1785 	cmd->t_state = TRANSPORT_PROCESSING;
1786 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1787 	spin_unlock_irq(&cmd->t_state_lock);
1788 	/*
1789 	 * Perform WRITE_INSERT of PI using software emulation when backend
1790 	 * device has PI enabled, if the transport has not already generated
1791 	 * PI using hardware WRITE_INSERT offload.
1792 	 */
1793 	if (cmd->prot_op == TARGET_PROT_DOUT_INSERT) {
1794 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1795 			sbc_dif_generate(cmd);
1796 	}
1797 
1798 	if (target_handle_task_attr(cmd)) {
1799 		spin_lock_irq(&cmd->t_state_lock);
1800 		cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT;
1801 		spin_unlock_irq(&cmd->t_state_lock);
1802 		return;
1803 	}
1804 
1805 	__target_execute_cmd(cmd);
1806 }
1807 EXPORT_SYMBOL(target_execute_cmd);
1808 
1809 /*
1810  * Process all commands up to the last received ORDERED task attribute which
1811  * requires another blocking boundary
1812  */
1813 static void target_restart_delayed_cmds(struct se_device *dev)
1814 {
1815 	for (;;) {
1816 		struct se_cmd *cmd;
1817 
1818 		spin_lock(&dev->delayed_cmd_lock);
1819 		if (list_empty(&dev->delayed_cmd_list)) {
1820 			spin_unlock(&dev->delayed_cmd_lock);
1821 			break;
1822 		}
1823 
1824 		cmd = list_entry(dev->delayed_cmd_list.next,
1825 				 struct se_cmd, se_delayed_node);
1826 		list_del(&cmd->se_delayed_node);
1827 		spin_unlock(&dev->delayed_cmd_lock);
1828 
1829 		__target_execute_cmd(cmd);
1830 
1831 		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1832 			break;
1833 	}
1834 }
1835 
1836 /*
1837  * Called from I/O completion to determine which dormant/delayed
1838  * and ordered cmds need to have their tasks added to the execution queue.
1839  */
1840 static void transport_complete_task_attr(struct se_cmd *cmd)
1841 {
1842 	struct se_device *dev = cmd->se_dev;
1843 
1844 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1845 		return;
1846 
1847 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1848 		atomic_dec_mb(&dev->simple_cmds);
1849 		dev->dev_cur_ordered_id++;
1850 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1851 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1852 			cmd->se_ordered_id);
1853 	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1854 		dev->dev_cur_ordered_id++;
1855 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1856 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1857 			cmd->se_ordered_id);
1858 	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1859 		atomic_dec_mb(&dev->dev_ordered_sync);
1860 
1861 		dev->dev_cur_ordered_id++;
1862 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1863 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1864 	}
1865 
1866 	target_restart_delayed_cmds(dev);
1867 }
1868 
1869 static void transport_complete_qf(struct se_cmd *cmd)
1870 {
1871 	int ret = 0;
1872 
1873 	transport_complete_task_attr(cmd);
1874 
1875 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1876 		trace_target_cmd_complete(cmd);
1877 		ret = cmd->se_tfo->queue_status(cmd);
1878 		goto out;
1879 	}
1880 
1881 	switch (cmd->data_direction) {
1882 	case DMA_FROM_DEVICE:
1883 		trace_target_cmd_complete(cmd);
1884 		ret = cmd->se_tfo->queue_data_in(cmd);
1885 		break;
1886 	case DMA_TO_DEVICE:
1887 		if (cmd->se_cmd_flags & SCF_BIDI) {
1888 			ret = cmd->se_tfo->queue_data_in(cmd);
1889 			if (ret < 0)
1890 				break;
1891 		}
1892 		/* Fall through for DMA_TO_DEVICE */
1893 	case DMA_NONE:
1894 		trace_target_cmd_complete(cmd);
1895 		ret = cmd->se_tfo->queue_status(cmd);
1896 		break;
1897 	default:
1898 		break;
1899 	}
1900 
1901 out:
1902 	if (ret < 0) {
1903 		transport_handle_queue_full(cmd, cmd->se_dev);
1904 		return;
1905 	}
1906 	transport_lun_remove_cmd(cmd);
1907 	transport_cmd_check_stop_to_fabric(cmd);
1908 }
1909 
1910 static void transport_handle_queue_full(
1911 	struct se_cmd *cmd,
1912 	struct se_device *dev)
1913 {
1914 	spin_lock_irq(&dev->qf_cmd_lock);
1915 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1916 	atomic_inc_mb(&dev->dev_qf_count);
1917 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1918 
1919 	schedule_work(&cmd->se_dev->qf_work_queue);
1920 }
1921 
1922 static bool target_check_read_strip(struct se_cmd *cmd)
1923 {
1924 	sense_reason_t rc;
1925 
1926 	if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
1927 		rc = sbc_dif_read_strip(cmd);
1928 		if (rc) {
1929 			cmd->pi_err = rc;
1930 			return true;
1931 		}
1932 	}
1933 
1934 	return false;
1935 }
1936 
1937 static void target_complete_ok_work(struct work_struct *work)
1938 {
1939 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1940 	int ret;
1941 
1942 	/*
1943 	 * Check if we need to move delayed/dormant tasks from cmds on the
1944 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1945 	 * Attribute.
1946 	 */
1947 	transport_complete_task_attr(cmd);
1948 
1949 	/*
1950 	 * Check to schedule QUEUE_FULL work, or execute an existing
1951 	 * cmd->transport_qf_callback()
1952 	 */
1953 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1954 		schedule_work(&cmd->se_dev->qf_work_queue);
1955 
1956 	/*
1957 	 * Check if we need to send a sense buffer from
1958 	 * the struct se_cmd in question.
1959 	 */
1960 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1961 		WARN_ON(!cmd->scsi_status);
1962 		ret = transport_send_check_condition_and_sense(
1963 					cmd, 0, 1);
1964 		if (ret == -EAGAIN || ret == -ENOMEM)
1965 			goto queue_full;
1966 
1967 		transport_lun_remove_cmd(cmd);
1968 		transport_cmd_check_stop_to_fabric(cmd);
1969 		return;
1970 	}
1971 	/*
1972 	 * Check for a callback, used by amongst other things
1973 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
1974 	 */
1975 	if (cmd->transport_complete_callback) {
1976 		sense_reason_t rc;
1977 
1978 		rc = cmd->transport_complete_callback(cmd);
1979 		if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
1980 			return;
1981 		} else if (rc) {
1982 			ret = transport_send_check_condition_and_sense(cmd,
1983 						rc, 0);
1984 			if (ret == -EAGAIN || ret == -ENOMEM)
1985 				goto queue_full;
1986 
1987 			transport_lun_remove_cmd(cmd);
1988 			transport_cmd_check_stop_to_fabric(cmd);
1989 			return;
1990 		}
1991 	}
1992 
1993 	switch (cmd->data_direction) {
1994 	case DMA_FROM_DEVICE:
1995 		spin_lock(&cmd->se_lun->lun_sep_lock);
1996 		if (cmd->se_lun->lun_sep) {
1997 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1998 					cmd->data_length;
1999 		}
2000 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2001 		/*
2002 		 * Perform READ_STRIP of PI using software emulation when
2003 		 * backend had PI enabled, if the transport will not be
2004 		 * performing hardware READ_STRIP offload.
2005 		 */
2006 		if (cmd->prot_op == TARGET_PROT_DIN_STRIP &&
2007 		    target_check_read_strip(cmd)) {
2008 			ret = transport_send_check_condition_and_sense(cmd,
2009 						cmd->pi_err, 0);
2010 			if (ret == -EAGAIN || ret == -ENOMEM)
2011 				goto queue_full;
2012 
2013 			transport_lun_remove_cmd(cmd);
2014 			transport_cmd_check_stop_to_fabric(cmd);
2015 			return;
2016 		}
2017 
2018 		trace_target_cmd_complete(cmd);
2019 		ret = cmd->se_tfo->queue_data_in(cmd);
2020 		if (ret == -EAGAIN || ret == -ENOMEM)
2021 			goto queue_full;
2022 		break;
2023 	case DMA_TO_DEVICE:
2024 		spin_lock(&cmd->se_lun->lun_sep_lock);
2025 		if (cmd->se_lun->lun_sep) {
2026 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2027 				cmd->data_length;
2028 		}
2029 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2030 		/*
2031 		 * Check if we need to send READ payload for BIDI-COMMAND
2032 		 */
2033 		if (cmd->se_cmd_flags & SCF_BIDI) {
2034 			spin_lock(&cmd->se_lun->lun_sep_lock);
2035 			if (cmd->se_lun->lun_sep) {
2036 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2037 					cmd->data_length;
2038 			}
2039 			spin_unlock(&cmd->se_lun->lun_sep_lock);
2040 			ret = cmd->se_tfo->queue_data_in(cmd);
2041 			if (ret == -EAGAIN || ret == -ENOMEM)
2042 				goto queue_full;
2043 			break;
2044 		}
2045 		/* Fall through for DMA_TO_DEVICE */
2046 	case DMA_NONE:
2047 		trace_target_cmd_complete(cmd);
2048 		ret = cmd->se_tfo->queue_status(cmd);
2049 		if (ret == -EAGAIN || ret == -ENOMEM)
2050 			goto queue_full;
2051 		break;
2052 	default:
2053 		break;
2054 	}
2055 
2056 	transport_lun_remove_cmd(cmd);
2057 	transport_cmd_check_stop_to_fabric(cmd);
2058 	return;
2059 
2060 queue_full:
2061 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2062 		" data_direction: %d\n", cmd, cmd->data_direction);
2063 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2064 	transport_handle_queue_full(cmd, cmd->se_dev);
2065 }
2066 
2067 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2068 {
2069 	struct scatterlist *sg;
2070 	int count;
2071 
2072 	for_each_sg(sgl, sg, nents, count)
2073 		__free_page(sg_page(sg));
2074 
2075 	kfree(sgl);
2076 }
2077 
2078 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2079 {
2080 	/*
2081 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2082 	 * emulation, and free + reset pointers if necessary..
2083 	 */
2084 	if (!cmd->t_data_sg_orig)
2085 		return;
2086 
2087 	kfree(cmd->t_data_sg);
2088 	cmd->t_data_sg = cmd->t_data_sg_orig;
2089 	cmd->t_data_sg_orig = NULL;
2090 	cmd->t_data_nents = cmd->t_data_nents_orig;
2091 	cmd->t_data_nents_orig = 0;
2092 }
2093 
2094 static inline void transport_free_pages(struct se_cmd *cmd)
2095 {
2096 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2097 		transport_reset_sgl_orig(cmd);
2098 		return;
2099 	}
2100 	transport_reset_sgl_orig(cmd);
2101 
2102 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2103 	cmd->t_data_sg = NULL;
2104 	cmd->t_data_nents = 0;
2105 
2106 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2107 	cmd->t_bidi_data_sg = NULL;
2108 	cmd->t_bidi_data_nents = 0;
2109 
2110 	transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2111 	cmd->t_prot_sg = NULL;
2112 	cmd->t_prot_nents = 0;
2113 }
2114 
2115 /**
2116  * transport_release_cmd - free a command
2117  * @cmd:       command to free
2118  *
2119  * This routine unconditionally frees a command, and reference counting
2120  * or list removal must be done in the caller.
2121  */
2122 static int transport_release_cmd(struct se_cmd *cmd)
2123 {
2124 	BUG_ON(!cmd->se_tfo);
2125 
2126 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2127 		core_tmr_release_req(cmd->se_tmr_req);
2128 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2129 		kfree(cmd->t_task_cdb);
2130 	/*
2131 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2132 	 * the kref and call ->release_cmd() in kref callback.
2133 	 */
2134 	return target_put_sess_cmd(cmd->se_sess, cmd);
2135 }
2136 
2137 /**
2138  * transport_put_cmd - release a reference to a command
2139  * @cmd:       command to release
2140  *
2141  * This routine releases our reference to the command and frees it if possible.
2142  */
2143 static int transport_put_cmd(struct se_cmd *cmd)
2144 {
2145 	transport_free_pages(cmd);
2146 	return transport_release_cmd(cmd);
2147 }
2148 
2149 void *transport_kmap_data_sg(struct se_cmd *cmd)
2150 {
2151 	struct scatterlist *sg = cmd->t_data_sg;
2152 	struct page **pages;
2153 	int i;
2154 
2155 	/*
2156 	 * We need to take into account a possible offset here for fabrics like
2157 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2158 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2159 	 */
2160 	if (!cmd->t_data_nents)
2161 		return NULL;
2162 
2163 	BUG_ON(!sg);
2164 	if (cmd->t_data_nents == 1)
2165 		return kmap(sg_page(sg)) + sg->offset;
2166 
2167 	/* >1 page. use vmap */
2168 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2169 	if (!pages)
2170 		return NULL;
2171 
2172 	/* convert sg[] to pages[] */
2173 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2174 		pages[i] = sg_page(sg);
2175 	}
2176 
2177 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2178 	kfree(pages);
2179 	if (!cmd->t_data_vmap)
2180 		return NULL;
2181 
2182 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2183 }
2184 EXPORT_SYMBOL(transport_kmap_data_sg);
2185 
2186 void transport_kunmap_data_sg(struct se_cmd *cmd)
2187 {
2188 	if (!cmd->t_data_nents) {
2189 		return;
2190 	} else if (cmd->t_data_nents == 1) {
2191 		kunmap(sg_page(cmd->t_data_sg));
2192 		return;
2193 	}
2194 
2195 	vunmap(cmd->t_data_vmap);
2196 	cmd->t_data_vmap = NULL;
2197 }
2198 EXPORT_SYMBOL(transport_kunmap_data_sg);
2199 
2200 int
2201 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2202 		 bool zero_page)
2203 {
2204 	struct scatterlist *sg;
2205 	struct page *page;
2206 	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2207 	unsigned int nent;
2208 	int i = 0;
2209 
2210 	nent = DIV_ROUND_UP(length, PAGE_SIZE);
2211 	sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2212 	if (!sg)
2213 		return -ENOMEM;
2214 
2215 	sg_init_table(sg, nent);
2216 
2217 	while (length) {
2218 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2219 		page = alloc_page(GFP_KERNEL | zero_flag);
2220 		if (!page)
2221 			goto out;
2222 
2223 		sg_set_page(&sg[i], page, page_len, 0);
2224 		length -= page_len;
2225 		i++;
2226 	}
2227 	*sgl = sg;
2228 	*nents = nent;
2229 	return 0;
2230 
2231 out:
2232 	while (i > 0) {
2233 		i--;
2234 		__free_page(sg_page(&sg[i]));
2235 	}
2236 	kfree(sg);
2237 	return -ENOMEM;
2238 }
2239 
2240 /*
2241  * Allocate any required resources to execute the command.  For writes we
2242  * might not have the payload yet, so notify the fabric via a call to
2243  * ->write_pending instead. Otherwise place it on the execution queue.
2244  */
2245 sense_reason_t
2246 transport_generic_new_cmd(struct se_cmd *cmd)
2247 {
2248 	int ret = 0;
2249 
2250 	/*
2251 	 * Determine is the TCM fabric module has already allocated physical
2252 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2253 	 * beforehand.
2254 	 */
2255 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2256 	    cmd->data_length) {
2257 		bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2258 
2259 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2260 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2261 			u32 bidi_length;
2262 
2263 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2264 				bidi_length = cmd->t_task_nolb *
2265 					      cmd->se_dev->dev_attrib.block_size;
2266 			else
2267 				bidi_length = cmd->data_length;
2268 
2269 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2270 					       &cmd->t_bidi_data_nents,
2271 					       bidi_length, zero_flag);
2272 			if (ret < 0)
2273 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2274 		}
2275 
2276 		if (cmd->prot_op != TARGET_PROT_NORMAL) {
2277 			ret = target_alloc_sgl(&cmd->t_prot_sg,
2278 					       &cmd->t_prot_nents,
2279 					       cmd->prot_length, true);
2280 			if (ret < 0)
2281 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2282 		}
2283 
2284 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2285 				       cmd->data_length, zero_flag);
2286 		if (ret < 0)
2287 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2288 	}
2289 	/*
2290 	 * If this command is not a write we can execute it right here,
2291 	 * for write buffers we need to notify the fabric driver first
2292 	 * and let it call back once the write buffers are ready.
2293 	 */
2294 	target_add_to_state_list(cmd);
2295 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2296 		target_execute_cmd(cmd);
2297 		return 0;
2298 	}
2299 	transport_cmd_check_stop(cmd, false, true);
2300 
2301 	ret = cmd->se_tfo->write_pending(cmd);
2302 	if (ret == -EAGAIN || ret == -ENOMEM)
2303 		goto queue_full;
2304 
2305 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2306 	WARN_ON(ret);
2307 
2308 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2309 
2310 queue_full:
2311 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2312 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2313 	transport_handle_queue_full(cmd, cmd->se_dev);
2314 	return 0;
2315 }
2316 EXPORT_SYMBOL(transport_generic_new_cmd);
2317 
2318 static void transport_write_pending_qf(struct se_cmd *cmd)
2319 {
2320 	int ret;
2321 
2322 	ret = cmd->se_tfo->write_pending(cmd);
2323 	if (ret == -EAGAIN || ret == -ENOMEM) {
2324 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2325 			 cmd);
2326 		transport_handle_queue_full(cmd, cmd->se_dev);
2327 	}
2328 }
2329 
2330 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2331 {
2332 	unsigned long flags;
2333 	int ret = 0;
2334 
2335 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2336 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2337 			 transport_wait_for_tasks(cmd);
2338 
2339 		ret = transport_release_cmd(cmd);
2340 	} else {
2341 		if (wait_for_tasks)
2342 			transport_wait_for_tasks(cmd);
2343 		/*
2344 		 * Handle WRITE failure case where transport_generic_new_cmd()
2345 		 * has already added se_cmd to state_list, but fabric has
2346 		 * failed command before I/O submission.
2347 		 */
2348 		if (cmd->state_active) {
2349 			spin_lock_irqsave(&cmd->t_state_lock, flags);
2350 			target_remove_from_state_list(cmd);
2351 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2352 		}
2353 
2354 		if (cmd->se_lun)
2355 			transport_lun_remove_cmd(cmd);
2356 
2357 		ret = transport_put_cmd(cmd);
2358 	}
2359 	return ret;
2360 }
2361 EXPORT_SYMBOL(transport_generic_free_cmd);
2362 
2363 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2364  * @se_sess:	session to reference
2365  * @se_cmd:	command descriptor to add
2366  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2367  */
2368 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2369 			       bool ack_kref)
2370 {
2371 	unsigned long flags;
2372 	int ret = 0;
2373 
2374 	/*
2375 	 * Add a second kref if the fabric caller is expecting to handle
2376 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2377 	 * invocations before se_cmd descriptor release.
2378 	 */
2379 	if (ack_kref) {
2380 		kref_get(&se_cmd->cmd_kref);
2381 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2382 	}
2383 
2384 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2385 	if (se_sess->sess_tearing_down) {
2386 		ret = -ESHUTDOWN;
2387 		goto out;
2388 	}
2389 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2390 out:
2391 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2392 	return ret;
2393 }
2394 EXPORT_SYMBOL(target_get_sess_cmd);
2395 
2396 static void target_release_cmd_kref(struct kref *kref)
2397 {
2398 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2399 	struct se_session *se_sess = se_cmd->se_sess;
2400 
2401 	if (list_empty(&se_cmd->se_cmd_list)) {
2402 		spin_unlock(&se_sess->sess_cmd_lock);
2403 		se_cmd->se_tfo->release_cmd(se_cmd);
2404 		return;
2405 	}
2406 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2407 		spin_unlock(&se_sess->sess_cmd_lock);
2408 		complete(&se_cmd->cmd_wait_comp);
2409 		return;
2410 	}
2411 	list_del(&se_cmd->se_cmd_list);
2412 	spin_unlock(&se_sess->sess_cmd_lock);
2413 
2414 	se_cmd->se_tfo->release_cmd(se_cmd);
2415 }
2416 
2417 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2418  * @se_sess:	session to reference
2419  * @se_cmd:	command descriptor to drop
2420  */
2421 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2422 {
2423 	if (!se_sess) {
2424 		se_cmd->se_tfo->release_cmd(se_cmd);
2425 		return 1;
2426 	}
2427 	return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2428 			&se_sess->sess_cmd_lock);
2429 }
2430 EXPORT_SYMBOL(target_put_sess_cmd);
2431 
2432 /* target_sess_cmd_list_set_waiting - Flag all commands in
2433  *         sess_cmd_list to complete cmd_wait_comp.  Set
2434  *         sess_tearing_down so no more commands are queued.
2435  * @se_sess:	session to flag
2436  */
2437 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2438 {
2439 	struct se_cmd *se_cmd;
2440 	unsigned long flags;
2441 
2442 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2443 	if (se_sess->sess_tearing_down) {
2444 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2445 		return;
2446 	}
2447 	se_sess->sess_tearing_down = 1;
2448 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2449 
2450 	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2451 		se_cmd->cmd_wait_set = 1;
2452 
2453 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2454 }
2455 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2456 
2457 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2458  * @se_sess:    session to wait for active I/O
2459  */
2460 void target_wait_for_sess_cmds(struct se_session *se_sess)
2461 {
2462 	struct se_cmd *se_cmd, *tmp_cmd;
2463 	unsigned long flags;
2464 
2465 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2466 				&se_sess->sess_wait_list, se_cmd_list) {
2467 		list_del(&se_cmd->se_cmd_list);
2468 
2469 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2470 			" %d\n", se_cmd, se_cmd->t_state,
2471 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2472 
2473 		wait_for_completion(&se_cmd->cmd_wait_comp);
2474 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2475 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2476 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2477 
2478 		se_cmd->se_tfo->release_cmd(se_cmd);
2479 	}
2480 
2481 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2482 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2483 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2484 
2485 }
2486 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2487 
2488 static int transport_clear_lun_ref_thread(void *p)
2489 {
2490 	struct se_lun *lun = p;
2491 
2492 	percpu_ref_kill(&lun->lun_ref);
2493 
2494 	wait_for_completion(&lun->lun_ref_comp);
2495 	complete(&lun->lun_shutdown_comp);
2496 
2497 	return 0;
2498 }
2499 
2500 int transport_clear_lun_ref(struct se_lun *lun)
2501 {
2502 	struct task_struct *kt;
2503 
2504 	kt = kthread_run(transport_clear_lun_ref_thread, lun,
2505 			"tcm_cl_%u", lun->unpacked_lun);
2506 	if (IS_ERR(kt)) {
2507 		pr_err("Unable to start clear_lun thread\n");
2508 		return PTR_ERR(kt);
2509 	}
2510 	wait_for_completion(&lun->lun_shutdown_comp);
2511 
2512 	return 0;
2513 }
2514 
2515 /**
2516  * transport_wait_for_tasks - wait for completion to occur
2517  * @cmd:	command to wait
2518  *
2519  * Called from frontend fabric context to wait for storage engine
2520  * to pause and/or release frontend generated struct se_cmd.
2521  */
2522 bool transport_wait_for_tasks(struct se_cmd *cmd)
2523 {
2524 	unsigned long flags;
2525 
2526 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2527 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2528 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2529 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2530 		return false;
2531 	}
2532 
2533 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2534 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2535 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2536 		return false;
2537 	}
2538 
2539 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2540 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2541 		return false;
2542 	}
2543 
2544 	cmd->transport_state |= CMD_T_STOP;
2545 
2546 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2547 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2548 		cmd, cmd->se_tfo->get_task_tag(cmd),
2549 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2550 
2551 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2552 
2553 	wait_for_completion(&cmd->t_transport_stop_comp);
2554 
2555 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2556 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2557 
2558 	pr_debug("wait_for_tasks: Stopped wait_for_completion("
2559 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2560 		cmd->se_tfo->get_task_tag(cmd));
2561 
2562 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2563 
2564 	return true;
2565 }
2566 EXPORT_SYMBOL(transport_wait_for_tasks);
2567 
2568 static int transport_get_sense_codes(
2569 	struct se_cmd *cmd,
2570 	u8 *asc,
2571 	u8 *ascq)
2572 {
2573 	*asc = cmd->scsi_asc;
2574 	*ascq = cmd->scsi_ascq;
2575 
2576 	return 0;
2577 }
2578 
2579 static
2580 void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
2581 {
2582 	/* Place failed LBA in sense data information descriptor 0. */
2583 	buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
2584 	buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
2585 	buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
2586 	buffer[SPC_VALIDITY_OFFSET] = 0x80;
2587 
2588 	/* Descriptor Information: failing sector */
2589 	put_unaligned_be64(bad_sector, &buffer[12]);
2590 }
2591 
2592 int
2593 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2594 		sense_reason_t reason, int from_transport)
2595 {
2596 	unsigned char *buffer = cmd->sense_buffer;
2597 	unsigned long flags;
2598 	u8 asc = 0, ascq = 0;
2599 
2600 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2601 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2602 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2603 		return 0;
2604 	}
2605 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2606 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2607 
2608 	if (!reason && from_transport)
2609 		goto after_reason;
2610 
2611 	if (!from_transport)
2612 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2613 
2614 	/*
2615 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2616 	 * SENSE KEY values from include/scsi/scsi.h
2617 	 */
2618 	switch (reason) {
2619 	case TCM_NO_SENSE:
2620 		/* CURRENT ERROR */
2621 		buffer[0] = 0x70;
2622 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2623 		/* Not Ready */
2624 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2625 		/* NO ADDITIONAL SENSE INFORMATION */
2626 		buffer[SPC_ASC_KEY_OFFSET] = 0;
2627 		buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2628 		break;
2629 	case TCM_NON_EXISTENT_LUN:
2630 		/* CURRENT ERROR */
2631 		buffer[0] = 0x70;
2632 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2633 		/* ILLEGAL REQUEST */
2634 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2635 		/* LOGICAL UNIT NOT SUPPORTED */
2636 		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2637 		break;
2638 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2639 	case TCM_SECTOR_COUNT_TOO_MANY:
2640 		/* CURRENT ERROR */
2641 		buffer[0] = 0x70;
2642 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2643 		/* ILLEGAL REQUEST */
2644 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2645 		/* INVALID COMMAND OPERATION CODE */
2646 		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2647 		break;
2648 	case TCM_UNKNOWN_MODE_PAGE:
2649 		/* CURRENT ERROR */
2650 		buffer[0] = 0x70;
2651 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2652 		/* ILLEGAL REQUEST */
2653 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2654 		/* INVALID FIELD IN CDB */
2655 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2656 		break;
2657 	case TCM_CHECK_CONDITION_ABORT_CMD:
2658 		/* CURRENT ERROR */
2659 		buffer[0] = 0x70;
2660 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2661 		/* ABORTED COMMAND */
2662 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2663 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2664 		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2665 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2666 		break;
2667 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2668 		/* CURRENT ERROR */
2669 		buffer[0] = 0x70;
2670 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2671 		/* ABORTED COMMAND */
2672 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2673 		/* WRITE ERROR */
2674 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2675 		/* NOT ENOUGH UNSOLICITED DATA */
2676 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2677 		break;
2678 	case TCM_INVALID_CDB_FIELD:
2679 		/* CURRENT ERROR */
2680 		buffer[0] = 0x70;
2681 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2682 		/* ILLEGAL REQUEST */
2683 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2684 		/* INVALID FIELD IN CDB */
2685 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2686 		break;
2687 	case TCM_INVALID_PARAMETER_LIST:
2688 		/* CURRENT ERROR */
2689 		buffer[0] = 0x70;
2690 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2691 		/* ILLEGAL REQUEST */
2692 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2693 		/* INVALID FIELD IN PARAMETER LIST */
2694 		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2695 		break;
2696 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2697 		/* CURRENT ERROR */
2698 		buffer[0] = 0x70;
2699 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2700 		/* ILLEGAL REQUEST */
2701 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2702 		/* PARAMETER LIST LENGTH ERROR */
2703 		buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2704 		break;
2705 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2706 		/* CURRENT ERROR */
2707 		buffer[0] = 0x70;
2708 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2709 		/* ABORTED COMMAND */
2710 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2711 		/* WRITE ERROR */
2712 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2713 		/* UNEXPECTED_UNSOLICITED_DATA */
2714 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2715 		break;
2716 	case TCM_SERVICE_CRC_ERROR:
2717 		/* CURRENT ERROR */
2718 		buffer[0] = 0x70;
2719 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2720 		/* ABORTED COMMAND */
2721 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2722 		/* PROTOCOL SERVICE CRC ERROR */
2723 		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2724 		/* N/A */
2725 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2726 		break;
2727 	case TCM_SNACK_REJECTED:
2728 		/* CURRENT ERROR */
2729 		buffer[0] = 0x70;
2730 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2731 		/* ABORTED COMMAND */
2732 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2733 		/* READ ERROR */
2734 		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2735 		/* FAILED RETRANSMISSION REQUEST */
2736 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2737 		break;
2738 	case TCM_WRITE_PROTECTED:
2739 		/* CURRENT ERROR */
2740 		buffer[0] = 0x70;
2741 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2742 		/* DATA PROTECT */
2743 		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2744 		/* WRITE PROTECTED */
2745 		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2746 		break;
2747 	case TCM_ADDRESS_OUT_OF_RANGE:
2748 		/* CURRENT ERROR */
2749 		buffer[0] = 0x70;
2750 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2751 		/* ILLEGAL REQUEST */
2752 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2753 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2754 		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2755 		break;
2756 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2757 		/* CURRENT ERROR */
2758 		buffer[0] = 0x70;
2759 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2760 		/* UNIT ATTENTION */
2761 		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2762 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2763 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2764 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2765 		break;
2766 	case TCM_CHECK_CONDITION_NOT_READY:
2767 		/* CURRENT ERROR */
2768 		buffer[0] = 0x70;
2769 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2770 		/* Not Ready */
2771 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2772 		transport_get_sense_codes(cmd, &asc, &ascq);
2773 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2774 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2775 		break;
2776 	case TCM_MISCOMPARE_VERIFY:
2777 		/* CURRENT ERROR */
2778 		buffer[0] = 0x70;
2779 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2780 		buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2781 		/* MISCOMPARE DURING VERIFY OPERATION */
2782 		buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2783 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2784 		break;
2785 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2786 		/* CURRENT ERROR */
2787 		buffer[0] = 0x70;
2788 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2789 		/* ILLEGAL REQUEST */
2790 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2791 		/* LOGICAL BLOCK GUARD CHECK FAILED */
2792 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2793 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
2794 		transport_err_sector_info(buffer, cmd->bad_sector);
2795 		break;
2796 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2797 		/* CURRENT ERROR */
2798 		buffer[0] = 0x70;
2799 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2800 		/* ILLEGAL REQUEST */
2801 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2802 		/* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2803 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2804 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
2805 		transport_err_sector_info(buffer, cmd->bad_sector);
2806 		break;
2807 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2808 		/* CURRENT ERROR */
2809 		buffer[0] = 0x70;
2810 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2811 		/* ILLEGAL REQUEST */
2812 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2813 		/* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2814 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2815 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2816 		transport_err_sector_info(buffer, cmd->bad_sector);
2817 		break;
2818 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2819 	default:
2820 		/* CURRENT ERROR */
2821 		buffer[0] = 0x70;
2822 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2823 		/*
2824 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2825 		 * Solaris initiators.  Returning NOT READY instead means the
2826 		 * operations will be retried a finite number of times and we
2827 		 * can survive intermittent errors.
2828 		 */
2829 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2830 		/* LOGICAL UNIT COMMUNICATION FAILURE */
2831 		buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2832 		break;
2833 	}
2834 	/*
2835 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
2836 	 */
2837 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2838 	/*
2839 	 * Automatically padded, this value is encoded in the fabric's
2840 	 * data_length response PDU containing the SCSI defined sense data.
2841 	 */
2842 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2843 
2844 after_reason:
2845 	trace_target_cmd_complete(cmd);
2846 	return cmd->se_tfo->queue_status(cmd);
2847 }
2848 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2849 
2850 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2851 {
2852 	if (!(cmd->transport_state & CMD_T_ABORTED))
2853 		return 0;
2854 
2855 	/*
2856 	 * If cmd has been aborted but either no status is to be sent or it has
2857 	 * already been sent, just return
2858 	 */
2859 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
2860 		return 1;
2861 
2862 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2863 		 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2864 
2865 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2866 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2867 	trace_target_cmd_complete(cmd);
2868 	cmd->se_tfo->queue_status(cmd);
2869 
2870 	return 1;
2871 }
2872 EXPORT_SYMBOL(transport_check_aborted_status);
2873 
2874 void transport_send_task_abort(struct se_cmd *cmd)
2875 {
2876 	unsigned long flags;
2877 
2878 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2879 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
2880 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2881 		return;
2882 	}
2883 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2884 
2885 	/*
2886 	 * If there are still expected incoming fabric WRITEs, we wait
2887 	 * until until they have completed before sending a TASK_ABORTED
2888 	 * response.  This response with TASK_ABORTED status will be
2889 	 * queued back to fabric module by transport_check_aborted_status().
2890 	 */
2891 	if (cmd->data_direction == DMA_TO_DEVICE) {
2892 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2893 			cmd->transport_state |= CMD_T_ABORTED;
2894 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
2895 			return;
2896 		}
2897 	}
2898 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2899 
2900 	transport_lun_remove_cmd(cmd);
2901 
2902 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2903 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
2904 		cmd->se_tfo->get_task_tag(cmd));
2905 
2906 	trace_target_cmd_complete(cmd);
2907 	cmd->se_tfo->queue_status(cmd);
2908 }
2909 
2910 static void target_tmr_work(struct work_struct *work)
2911 {
2912 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2913 	struct se_device *dev = cmd->se_dev;
2914 	struct se_tmr_req *tmr = cmd->se_tmr_req;
2915 	int ret;
2916 
2917 	switch (tmr->function) {
2918 	case TMR_ABORT_TASK:
2919 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
2920 		break;
2921 	case TMR_ABORT_TASK_SET:
2922 	case TMR_CLEAR_ACA:
2923 	case TMR_CLEAR_TASK_SET:
2924 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2925 		break;
2926 	case TMR_LUN_RESET:
2927 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2928 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2929 					 TMR_FUNCTION_REJECTED;
2930 		break;
2931 	case TMR_TARGET_WARM_RESET:
2932 		tmr->response = TMR_FUNCTION_REJECTED;
2933 		break;
2934 	case TMR_TARGET_COLD_RESET:
2935 		tmr->response = TMR_FUNCTION_REJECTED;
2936 		break;
2937 	default:
2938 		pr_err("Uknown TMR function: 0x%02x.\n",
2939 				tmr->function);
2940 		tmr->response = TMR_FUNCTION_REJECTED;
2941 		break;
2942 	}
2943 
2944 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2945 	cmd->se_tfo->queue_tm_rsp(cmd);
2946 
2947 	transport_cmd_check_stop_to_fabric(cmd);
2948 }
2949 
2950 int transport_generic_handle_tmr(
2951 	struct se_cmd *cmd)
2952 {
2953 	unsigned long flags;
2954 
2955 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2956 	cmd->transport_state |= CMD_T_ACTIVE;
2957 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2958 
2959 	INIT_WORK(&cmd->work, target_tmr_work);
2960 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2961 	return 0;
2962 }
2963 EXPORT_SYMBOL(transport_generic_handle_tmr);
2964