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