xref: /linux/drivers/target/target_core_transport.c (revision 4413e16d9d21673bb5048a2e542f1aaa00015c2e)
1 /*******************************************************************************
2  * Filename:  target_core_transport.c
3  *
4  * This file contains the Generic Target Engine Core.
5  *
6  * Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc.
7  * Copyright (c) 2005, 2006, 2007 SBE, Inc.
8  * Copyright (c) 2007-2010 Rising Tide Systems
9  * Copyright (c) 2008-2010 Linux-iSCSI.org
10  *
11  * Nicholas A. Bellinger <nab@kernel.org>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
26  *
27  ******************************************************************************/
28 
29 #include <linux/net.h>
30 #include <linux/delay.h>
31 #include <linux/string.h>
32 #include <linux/timer.h>
33 #include <linux/slab.h>
34 #include <linux/blkdev.h>
35 #include <linux/spinlock.h>
36 #include <linux/kthread.h>
37 #include <linux/in.h>
38 #include <linux/cdrom.h>
39 #include <linux/module.h>
40 #include <linux/ratelimit.h>
41 #include <asm/unaligned.h>
42 #include <net/sock.h>
43 #include <net/tcp.h>
44 #include <scsi/scsi.h>
45 #include <scsi/scsi_cmnd.h>
46 #include <scsi/scsi_tcq.h>
47 
48 #include <target/target_core_base.h>
49 #include <target/target_core_backend.h>
50 #include <target/target_core_fabric.h>
51 #include <target/target_core_configfs.h>
52 
53 #include "target_core_internal.h"
54 #include "target_core_alua.h"
55 #include "target_core_pr.h"
56 #include "target_core_ua.h"
57 
58 static int sub_api_initialized;
59 
60 static struct workqueue_struct *target_completion_wq;
61 static struct kmem_cache *se_sess_cache;
62 struct kmem_cache *se_ua_cache;
63 struct kmem_cache *t10_pr_reg_cache;
64 struct kmem_cache *t10_alua_lu_gp_cache;
65 struct kmem_cache *t10_alua_lu_gp_mem_cache;
66 struct kmem_cache *t10_alua_tg_pt_gp_cache;
67 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
68 
69 static void transport_complete_task_attr(struct se_cmd *cmd);
70 static void transport_handle_queue_full(struct se_cmd *cmd,
71 		struct se_device *dev);
72 static int transport_generic_get_mem(struct se_cmd *cmd);
73 static int target_get_sess_cmd(struct se_session *, struct se_cmd *, bool);
74 static void transport_put_cmd(struct se_cmd *cmd);
75 static int transport_set_sense_codes(struct se_cmd *cmd, u8 asc, u8 ascq);
76 static void target_complete_ok_work(struct work_struct *work);
77 
78 int init_se_kmem_caches(void)
79 {
80 	se_sess_cache = kmem_cache_create("se_sess_cache",
81 			sizeof(struct se_session), __alignof__(struct se_session),
82 			0, NULL);
83 	if (!se_sess_cache) {
84 		pr_err("kmem_cache_create() for struct se_session"
85 				" failed\n");
86 		goto out;
87 	}
88 	se_ua_cache = kmem_cache_create("se_ua_cache",
89 			sizeof(struct se_ua), __alignof__(struct se_ua),
90 			0, NULL);
91 	if (!se_ua_cache) {
92 		pr_err("kmem_cache_create() for struct se_ua failed\n");
93 		goto out_free_sess_cache;
94 	}
95 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
96 			sizeof(struct t10_pr_registration),
97 			__alignof__(struct t10_pr_registration), 0, NULL);
98 	if (!t10_pr_reg_cache) {
99 		pr_err("kmem_cache_create() for struct t10_pr_registration"
100 				" failed\n");
101 		goto out_free_ua_cache;
102 	}
103 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
104 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
105 			0, NULL);
106 	if (!t10_alua_lu_gp_cache) {
107 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
108 				" failed\n");
109 		goto out_free_pr_reg_cache;
110 	}
111 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
112 			sizeof(struct t10_alua_lu_gp_member),
113 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
114 	if (!t10_alua_lu_gp_mem_cache) {
115 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
116 				"cache failed\n");
117 		goto out_free_lu_gp_cache;
118 	}
119 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
120 			sizeof(struct t10_alua_tg_pt_gp),
121 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
122 	if (!t10_alua_tg_pt_gp_cache) {
123 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
124 				"cache failed\n");
125 		goto out_free_lu_gp_mem_cache;
126 	}
127 	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
128 			"t10_alua_tg_pt_gp_mem_cache",
129 			sizeof(struct t10_alua_tg_pt_gp_member),
130 			__alignof__(struct t10_alua_tg_pt_gp_member),
131 			0, NULL);
132 	if (!t10_alua_tg_pt_gp_mem_cache) {
133 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
134 				"mem_t failed\n");
135 		goto out_free_tg_pt_gp_cache;
136 	}
137 
138 	target_completion_wq = alloc_workqueue("target_completion",
139 					       WQ_MEM_RECLAIM, 0);
140 	if (!target_completion_wq)
141 		goto out_free_tg_pt_gp_mem_cache;
142 
143 	return 0;
144 
145 out_free_tg_pt_gp_mem_cache:
146 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
147 out_free_tg_pt_gp_cache:
148 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
149 out_free_lu_gp_mem_cache:
150 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
151 out_free_lu_gp_cache:
152 	kmem_cache_destroy(t10_alua_lu_gp_cache);
153 out_free_pr_reg_cache:
154 	kmem_cache_destroy(t10_pr_reg_cache);
155 out_free_ua_cache:
156 	kmem_cache_destroy(se_ua_cache);
157 out_free_sess_cache:
158 	kmem_cache_destroy(se_sess_cache);
159 out:
160 	return -ENOMEM;
161 }
162 
163 void release_se_kmem_caches(void)
164 {
165 	destroy_workqueue(target_completion_wq);
166 	kmem_cache_destroy(se_sess_cache);
167 	kmem_cache_destroy(se_ua_cache);
168 	kmem_cache_destroy(t10_pr_reg_cache);
169 	kmem_cache_destroy(t10_alua_lu_gp_cache);
170 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
171 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
172 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
173 }
174 
175 /* This code ensures unique mib indexes are handed out. */
176 static DEFINE_SPINLOCK(scsi_mib_index_lock);
177 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
178 
179 /*
180  * Allocate a new row index for the entry type specified
181  */
182 u32 scsi_get_new_index(scsi_index_t type)
183 {
184 	u32 new_index;
185 
186 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
187 
188 	spin_lock(&scsi_mib_index_lock);
189 	new_index = ++scsi_mib_index[type];
190 	spin_unlock(&scsi_mib_index_lock);
191 
192 	return new_index;
193 }
194 
195 void transport_subsystem_check_init(void)
196 {
197 	int ret;
198 
199 	if (sub_api_initialized)
200 		return;
201 
202 	ret = request_module("target_core_iblock");
203 	if (ret != 0)
204 		pr_err("Unable to load target_core_iblock\n");
205 
206 	ret = request_module("target_core_file");
207 	if (ret != 0)
208 		pr_err("Unable to load target_core_file\n");
209 
210 	ret = request_module("target_core_pscsi");
211 	if (ret != 0)
212 		pr_err("Unable to load target_core_pscsi\n");
213 
214 	ret = request_module("target_core_stgt");
215 	if (ret != 0)
216 		pr_err("Unable to load target_core_stgt\n");
217 
218 	sub_api_initialized = 1;
219 	return;
220 }
221 
222 struct se_session *transport_init_session(void)
223 {
224 	struct se_session *se_sess;
225 
226 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
227 	if (!se_sess) {
228 		pr_err("Unable to allocate struct se_session from"
229 				" se_sess_cache\n");
230 		return ERR_PTR(-ENOMEM);
231 	}
232 	INIT_LIST_HEAD(&se_sess->sess_list);
233 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
234 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
235 	spin_lock_init(&se_sess->sess_cmd_lock);
236 	kref_init(&se_sess->sess_kref);
237 
238 	return se_sess;
239 }
240 EXPORT_SYMBOL(transport_init_session);
241 
242 /*
243  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
244  */
245 void __transport_register_session(
246 	struct se_portal_group *se_tpg,
247 	struct se_node_acl *se_nacl,
248 	struct se_session *se_sess,
249 	void *fabric_sess_ptr)
250 {
251 	unsigned char buf[PR_REG_ISID_LEN];
252 
253 	se_sess->se_tpg = se_tpg;
254 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
255 	/*
256 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
257 	 *
258 	 * Only set for struct se_session's that will actually be moving I/O.
259 	 * eg: *NOT* discovery sessions.
260 	 */
261 	if (se_nacl) {
262 		/*
263 		 * If the fabric module supports an ISID based TransportID,
264 		 * save this value in binary from the fabric I_T Nexus now.
265 		 */
266 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
267 			memset(&buf[0], 0, PR_REG_ISID_LEN);
268 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
269 					&buf[0], PR_REG_ISID_LEN);
270 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
271 		}
272 		kref_get(&se_nacl->acl_kref);
273 
274 		spin_lock_irq(&se_nacl->nacl_sess_lock);
275 		/*
276 		 * The se_nacl->nacl_sess pointer will be set to the
277 		 * last active I_T Nexus for each struct se_node_acl.
278 		 */
279 		se_nacl->nacl_sess = se_sess;
280 
281 		list_add_tail(&se_sess->sess_acl_list,
282 			      &se_nacl->acl_sess_list);
283 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
284 	}
285 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
286 
287 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
288 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
289 }
290 EXPORT_SYMBOL(__transport_register_session);
291 
292 void transport_register_session(
293 	struct se_portal_group *se_tpg,
294 	struct se_node_acl *se_nacl,
295 	struct se_session *se_sess,
296 	void *fabric_sess_ptr)
297 {
298 	unsigned long flags;
299 
300 	spin_lock_irqsave(&se_tpg->session_lock, flags);
301 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
302 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
303 }
304 EXPORT_SYMBOL(transport_register_session);
305 
306 void target_release_session(struct kref *kref)
307 {
308 	struct se_session *se_sess = container_of(kref,
309 			struct se_session, sess_kref);
310 	struct se_portal_group *se_tpg = se_sess->se_tpg;
311 
312 	se_tpg->se_tpg_tfo->close_session(se_sess);
313 }
314 
315 void target_get_session(struct se_session *se_sess)
316 {
317 	kref_get(&se_sess->sess_kref);
318 }
319 EXPORT_SYMBOL(target_get_session);
320 
321 void target_put_session(struct se_session *se_sess)
322 {
323 	struct se_portal_group *tpg = se_sess->se_tpg;
324 
325 	if (tpg->se_tpg_tfo->put_session != NULL) {
326 		tpg->se_tpg_tfo->put_session(se_sess);
327 		return;
328 	}
329 	kref_put(&se_sess->sess_kref, target_release_session);
330 }
331 EXPORT_SYMBOL(target_put_session);
332 
333 static void target_complete_nacl(struct kref *kref)
334 {
335 	struct se_node_acl *nacl = container_of(kref,
336 				struct se_node_acl, acl_kref);
337 
338 	complete(&nacl->acl_free_comp);
339 }
340 
341 void target_put_nacl(struct se_node_acl *nacl)
342 {
343 	kref_put(&nacl->acl_kref, target_complete_nacl);
344 }
345 
346 void transport_deregister_session_configfs(struct se_session *se_sess)
347 {
348 	struct se_node_acl *se_nacl;
349 	unsigned long flags;
350 	/*
351 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
352 	 */
353 	se_nacl = se_sess->se_node_acl;
354 	if (se_nacl) {
355 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
356 		if (se_nacl->acl_stop == 0)
357 			list_del(&se_sess->sess_acl_list);
358 		/*
359 		 * If the session list is empty, then clear the pointer.
360 		 * Otherwise, set the struct se_session pointer from the tail
361 		 * element of the per struct se_node_acl active session list.
362 		 */
363 		if (list_empty(&se_nacl->acl_sess_list))
364 			se_nacl->nacl_sess = NULL;
365 		else {
366 			se_nacl->nacl_sess = container_of(
367 					se_nacl->acl_sess_list.prev,
368 					struct se_session, sess_acl_list);
369 		}
370 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
371 	}
372 }
373 EXPORT_SYMBOL(transport_deregister_session_configfs);
374 
375 void transport_free_session(struct se_session *se_sess)
376 {
377 	kmem_cache_free(se_sess_cache, se_sess);
378 }
379 EXPORT_SYMBOL(transport_free_session);
380 
381 void transport_deregister_session(struct se_session *se_sess)
382 {
383 	struct se_portal_group *se_tpg = se_sess->se_tpg;
384 	struct target_core_fabric_ops *se_tfo;
385 	struct se_node_acl *se_nacl;
386 	unsigned long flags;
387 	bool comp_nacl = true;
388 
389 	if (!se_tpg) {
390 		transport_free_session(se_sess);
391 		return;
392 	}
393 	se_tfo = se_tpg->se_tpg_tfo;
394 
395 	spin_lock_irqsave(&se_tpg->session_lock, flags);
396 	list_del(&se_sess->sess_list);
397 	se_sess->se_tpg = NULL;
398 	se_sess->fabric_sess_ptr = NULL;
399 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
400 
401 	/*
402 	 * Determine if we need to do extra work for this initiator node's
403 	 * struct se_node_acl if it had been previously dynamically generated.
404 	 */
405 	se_nacl = se_sess->se_node_acl;
406 
407 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
408 	if (se_nacl && se_nacl->dynamic_node_acl) {
409 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
410 			list_del(&se_nacl->acl_list);
411 			se_tpg->num_node_acls--;
412 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
413 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
414 			core_free_device_list_for_node(se_nacl, se_tpg);
415 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
416 
417 			comp_nacl = false;
418 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
419 		}
420 	}
421 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
422 
423 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
424 		se_tpg->se_tpg_tfo->get_fabric_name());
425 	/*
426 	 * If last kref is dropping now for an explict NodeACL, awake sleeping
427 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
428 	 * removal context.
429 	 */
430 	if (se_nacl && comp_nacl == true)
431 		target_put_nacl(se_nacl);
432 
433 	transport_free_session(se_sess);
434 }
435 EXPORT_SYMBOL(transport_deregister_session);
436 
437 /*
438  * Called with cmd->t_state_lock held.
439  */
440 static void target_remove_from_state_list(struct se_cmd *cmd)
441 {
442 	struct se_device *dev = cmd->se_dev;
443 	unsigned long flags;
444 
445 	if (!dev)
446 		return;
447 
448 	if (cmd->transport_state & CMD_T_BUSY)
449 		return;
450 
451 	spin_lock_irqsave(&dev->execute_task_lock, flags);
452 	if (cmd->state_active) {
453 		list_del(&cmd->state_list);
454 		cmd->state_active = false;
455 	}
456 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
457 }
458 
459 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists)
460 {
461 	unsigned long flags;
462 
463 	spin_lock_irqsave(&cmd->t_state_lock, flags);
464 	/*
465 	 * Determine if IOCTL context caller in requesting the stopping of this
466 	 * command for LUN shutdown purposes.
467 	 */
468 	if (cmd->transport_state & CMD_T_LUN_STOP) {
469 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
470 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
471 
472 		cmd->transport_state &= ~CMD_T_ACTIVE;
473 		if (remove_from_lists)
474 			target_remove_from_state_list(cmd);
475 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
476 
477 		complete(&cmd->transport_lun_stop_comp);
478 		return 1;
479 	}
480 
481 	if (remove_from_lists) {
482 		target_remove_from_state_list(cmd);
483 
484 		/*
485 		 * Clear struct se_cmd->se_lun before the handoff to FE.
486 		 */
487 		cmd->se_lun = NULL;
488 	}
489 
490 	/*
491 	 * Determine if frontend context caller is requesting the stopping of
492 	 * this command for frontend exceptions.
493 	 */
494 	if (cmd->transport_state & CMD_T_STOP) {
495 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
496 			__func__, __LINE__,
497 			cmd->se_tfo->get_task_tag(cmd));
498 
499 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
500 
501 		complete(&cmd->t_transport_stop_comp);
502 		return 1;
503 	}
504 
505 	cmd->transport_state &= ~CMD_T_ACTIVE;
506 	if (remove_from_lists) {
507 		/*
508 		 * Some fabric modules like tcm_loop can release
509 		 * their internally allocated I/O reference now and
510 		 * struct se_cmd now.
511 		 *
512 		 * Fabric modules are expected to return '1' here if the
513 		 * se_cmd being passed is released at this point,
514 		 * or zero if not being released.
515 		 */
516 		if (cmd->se_tfo->check_stop_free != NULL) {
517 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
518 			return cmd->se_tfo->check_stop_free(cmd);
519 		}
520 	}
521 
522 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
523 	return 0;
524 }
525 
526 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
527 {
528 	return transport_cmd_check_stop(cmd, true);
529 }
530 
531 static void transport_lun_remove_cmd(struct se_cmd *cmd)
532 {
533 	struct se_lun *lun = cmd->se_lun;
534 	unsigned long flags;
535 
536 	if (!lun)
537 		return;
538 
539 	spin_lock_irqsave(&cmd->t_state_lock, flags);
540 	if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
541 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
542 		target_remove_from_state_list(cmd);
543 	}
544 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
545 
546 	spin_lock_irqsave(&lun->lun_cmd_lock, flags);
547 	if (!list_empty(&cmd->se_lun_node))
548 		list_del_init(&cmd->se_lun_node);
549 	spin_unlock_irqrestore(&lun->lun_cmd_lock, flags);
550 }
551 
552 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
553 {
554 	if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
555 		transport_lun_remove_cmd(cmd);
556 
557 	if (transport_cmd_check_stop_to_fabric(cmd))
558 		return;
559 	if (remove)
560 		transport_put_cmd(cmd);
561 }
562 
563 static void target_complete_failure_work(struct work_struct *work)
564 {
565 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
566 
567 	transport_generic_request_failure(cmd);
568 }
569 
570 /*
571  * Used when asking transport to copy Sense Data from the underlying
572  * Linux/SCSI struct scsi_cmnd
573  */
574 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
575 {
576 	unsigned char *buffer = cmd->sense_buffer;
577 	struct se_device *dev = cmd->se_dev;
578 	u32 offset = 0;
579 
580 	WARN_ON(!cmd->se_lun);
581 
582 	if (!dev)
583 		return NULL;
584 
585 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
586 		return NULL;
587 
588 	offset = cmd->se_tfo->set_fabric_sense_len(cmd, TRANSPORT_SENSE_BUFFER);
589 
590 	/* Automatically padded */
591 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER + offset;
592 
593 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
594 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
595 	return &buffer[offset];
596 }
597 
598 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
599 {
600 	struct se_device *dev = cmd->se_dev;
601 	int success = scsi_status == GOOD;
602 	unsigned long flags;
603 
604 	cmd->scsi_status = scsi_status;
605 
606 
607 	spin_lock_irqsave(&cmd->t_state_lock, flags);
608 	cmd->transport_state &= ~CMD_T_BUSY;
609 
610 	if (dev && dev->transport->transport_complete) {
611 		dev->transport->transport_complete(cmd,
612 				cmd->t_data_sg,
613 				transport_get_sense_buffer(cmd));
614 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
615 			success = 1;
616 	}
617 
618 	/*
619 	 * See if we are waiting to complete for an exception condition.
620 	 */
621 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
622 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
623 		complete(&cmd->task_stop_comp);
624 		return;
625 	}
626 
627 	if (!success)
628 		cmd->transport_state |= CMD_T_FAILED;
629 
630 	/*
631 	 * Check for case where an explict ABORT_TASK has been received
632 	 * and transport_wait_for_tasks() will be waiting for completion..
633 	 */
634 	if (cmd->transport_state & CMD_T_ABORTED &&
635 	    cmd->transport_state & CMD_T_STOP) {
636 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
637 		complete(&cmd->t_transport_stop_comp);
638 		return;
639 	} else if (cmd->transport_state & CMD_T_FAILED) {
640 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
641 		INIT_WORK(&cmd->work, target_complete_failure_work);
642 	} else {
643 		INIT_WORK(&cmd->work, target_complete_ok_work);
644 	}
645 
646 	cmd->t_state = TRANSPORT_COMPLETE;
647 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
648 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
649 
650 	queue_work(target_completion_wq, &cmd->work);
651 }
652 EXPORT_SYMBOL(target_complete_cmd);
653 
654 static void target_add_to_state_list(struct se_cmd *cmd)
655 {
656 	struct se_device *dev = cmd->se_dev;
657 	unsigned long flags;
658 
659 	spin_lock_irqsave(&dev->execute_task_lock, flags);
660 	if (!cmd->state_active) {
661 		list_add_tail(&cmd->state_list, &dev->state_list);
662 		cmd->state_active = true;
663 	}
664 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
665 }
666 
667 /*
668  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
669  */
670 static void transport_write_pending_qf(struct se_cmd *cmd);
671 static void transport_complete_qf(struct se_cmd *cmd);
672 
673 static void target_qf_do_work(struct work_struct *work)
674 {
675 	struct se_device *dev = container_of(work, struct se_device,
676 					qf_work_queue);
677 	LIST_HEAD(qf_cmd_list);
678 	struct se_cmd *cmd, *cmd_tmp;
679 
680 	spin_lock_irq(&dev->qf_cmd_lock);
681 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
682 	spin_unlock_irq(&dev->qf_cmd_lock);
683 
684 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
685 		list_del(&cmd->se_qf_node);
686 		atomic_dec(&dev->dev_qf_count);
687 		smp_mb__after_atomic_dec();
688 
689 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
690 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
691 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
692 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
693 			: "UNKNOWN");
694 
695 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
696 			transport_write_pending_qf(cmd);
697 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
698 			transport_complete_qf(cmd);
699 	}
700 }
701 
702 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
703 {
704 	switch (cmd->data_direction) {
705 	case DMA_NONE:
706 		return "NONE";
707 	case DMA_FROM_DEVICE:
708 		return "READ";
709 	case DMA_TO_DEVICE:
710 		return "WRITE";
711 	case DMA_BIDIRECTIONAL:
712 		return "BIDI";
713 	default:
714 		break;
715 	}
716 
717 	return "UNKNOWN";
718 }
719 
720 void transport_dump_dev_state(
721 	struct se_device *dev,
722 	char *b,
723 	int *bl)
724 {
725 	*bl += sprintf(b + *bl, "Status: ");
726 	switch (dev->dev_status) {
727 	case TRANSPORT_DEVICE_ACTIVATED:
728 		*bl += sprintf(b + *bl, "ACTIVATED");
729 		break;
730 	case TRANSPORT_DEVICE_DEACTIVATED:
731 		*bl += sprintf(b + *bl, "DEACTIVATED");
732 		break;
733 	case TRANSPORT_DEVICE_SHUTDOWN:
734 		*bl += sprintf(b + *bl, "SHUTDOWN");
735 		break;
736 	case TRANSPORT_DEVICE_OFFLINE_ACTIVATED:
737 	case TRANSPORT_DEVICE_OFFLINE_DEACTIVATED:
738 		*bl += sprintf(b + *bl, "OFFLINE");
739 		break;
740 	default:
741 		*bl += sprintf(b + *bl, "UNKNOWN=%d", dev->dev_status);
742 		break;
743 	}
744 
745 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
746 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
747 		dev->se_sub_dev->se_dev_attrib.block_size,
748 		dev->se_sub_dev->se_dev_attrib.hw_max_sectors);
749 	*bl += sprintf(b + *bl, "        ");
750 }
751 
752 void transport_dump_vpd_proto_id(
753 	struct t10_vpd *vpd,
754 	unsigned char *p_buf,
755 	int p_buf_len)
756 {
757 	unsigned char buf[VPD_TMP_BUF_SIZE];
758 	int len;
759 
760 	memset(buf, 0, VPD_TMP_BUF_SIZE);
761 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
762 
763 	switch (vpd->protocol_identifier) {
764 	case 0x00:
765 		sprintf(buf+len, "Fibre Channel\n");
766 		break;
767 	case 0x10:
768 		sprintf(buf+len, "Parallel SCSI\n");
769 		break;
770 	case 0x20:
771 		sprintf(buf+len, "SSA\n");
772 		break;
773 	case 0x30:
774 		sprintf(buf+len, "IEEE 1394\n");
775 		break;
776 	case 0x40:
777 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
778 				" Protocol\n");
779 		break;
780 	case 0x50:
781 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
782 		break;
783 	case 0x60:
784 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
785 		break;
786 	case 0x70:
787 		sprintf(buf+len, "Automation/Drive Interface Transport"
788 				" Protocol\n");
789 		break;
790 	case 0x80:
791 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
792 		break;
793 	default:
794 		sprintf(buf+len, "Unknown 0x%02x\n",
795 				vpd->protocol_identifier);
796 		break;
797 	}
798 
799 	if (p_buf)
800 		strncpy(p_buf, buf, p_buf_len);
801 	else
802 		pr_debug("%s", buf);
803 }
804 
805 void
806 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
807 {
808 	/*
809 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
810 	 *
811 	 * from spc3r23.pdf section 7.5.1
812 	 */
813 	 if (page_83[1] & 0x80) {
814 		vpd->protocol_identifier = (page_83[0] & 0xf0);
815 		vpd->protocol_identifier_set = 1;
816 		transport_dump_vpd_proto_id(vpd, NULL, 0);
817 	}
818 }
819 EXPORT_SYMBOL(transport_set_vpd_proto_id);
820 
821 int transport_dump_vpd_assoc(
822 	struct t10_vpd *vpd,
823 	unsigned char *p_buf,
824 	int p_buf_len)
825 {
826 	unsigned char buf[VPD_TMP_BUF_SIZE];
827 	int ret = 0;
828 	int len;
829 
830 	memset(buf, 0, VPD_TMP_BUF_SIZE);
831 	len = sprintf(buf, "T10 VPD Identifier Association: ");
832 
833 	switch (vpd->association) {
834 	case 0x00:
835 		sprintf(buf+len, "addressed logical unit\n");
836 		break;
837 	case 0x10:
838 		sprintf(buf+len, "target port\n");
839 		break;
840 	case 0x20:
841 		sprintf(buf+len, "SCSI target device\n");
842 		break;
843 	default:
844 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
845 		ret = -EINVAL;
846 		break;
847 	}
848 
849 	if (p_buf)
850 		strncpy(p_buf, buf, p_buf_len);
851 	else
852 		pr_debug("%s", buf);
853 
854 	return ret;
855 }
856 
857 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
858 {
859 	/*
860 	 * The VPD identification association..
861 	 *
862 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
863 	 */
864 	vpd->association = (page_83[1] & 0x30);
865 	return transport_dump_vpd_assoc(vpd, NULL, 0);
866 }
867 EXPORT_SYMBOL(transport_set_vpd_assoc);
868 
869 int transport_dump_vpd_ident_type(
870 	struct t10_vpd *vpd,
871 	unsigned char *p_buf,
872 	int p_buf_len)
873 {
874 	unsigned char buf[VPD_TMP_BUF_SIZE];
875 	int ret = 0;
876 	int len;
877 
878 	memset(buf, 0, VPD_TMP_BUF_SIZE);
879 	len = sprintf(buf, "T10 VPD Identifier Type: ");
880 
881 	switch (vpd->device_identifier_type) {
882 	case 0x00:
883 		sprintf(buf+len, "Vendor specific\n");
884 		break;
885 	case 0x01:
886 		sprintf(buf+len, "T10 Vendor ID based\n");
887 		break;
888 	case 0x02:
889 		sprintf(buf+len, "EUI-64 based\n");
890 		break;
891 	case 0x03:
892 		sprintf(buf+len, "NAA\n");
893 		break;
894 	case 0x04:
895 		sprintf(buf+len, "Relative target port identifier\n");
896 		break;
897 	case 0x08:
898 		sprintf(buf+len, "SCSI name string\n");
899 		break;
900 	default:
901 		sprintf(buf+len, "Unsupported: 0x%02x\n",
902 				vpd->device_identifier_type);
903 		ret = -EINVAL;
904 		break;
905 	}
906 
907 	if (p_buf) {
908 		if (p_buf_len < strlen(buf)+1)
909 			return -EINVAL;
910 		strncpy(p_buf, buf, p_buf_len);
911 	} else {
912 		pr_debug("%s", buf);
913 	}
914 
915 	return ret;
916 }
917 
918 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
919 {
920 	/*
921 	 * The VPD identifier type..
922 	 *
923 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
924 	 */
925 	vpd->device_identifier_type = (page_83[1] & 0x0f);
926 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
927 }
928 EXPORT_SYMBOL(transport_set_vpd_ident_type);
929 
930 int transport_dump_vpd_ident(
931 	struct t10_vpd *vpd,
932 	unsigned char *p_buf,
933 	int p_buf_len)
934 {
935 	unsigned char buf[VPD_TMP_BUF_SIZE];
936 	int ret = 0;
937 
938 	memset(buf, 0, VPD_TMP_BUF_SIZE);
939 
940 	switch (vpd->device_identifier_code_set) {
941 	case 0x01: /* Binary */
942 		sprintf(buf, "T10 VPD Binary Device Identifier: %s\n",
943 			&vpd->device_identifier[0]);
944 		break;
945 	case 0x02: /* ASCII */
946 		sprintf(buf, "T10 VPD ASCII Device Identifier: %s\n",
947 			&vpd->device_identifier[0]);
948 		break;
949 	case 0x03: /* UTF-8 */
950 		sprintf(buf, "T10 VPD UTF-8 Device Identifier: %s\n",
951 			&vpd->device_identifier[0]);
952 		break;
953 	default:
954 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
955 			" 0x%02x", vpd->device_identifier_code_set);
956 		ret = -EINVAL;
957 		break;
958 	}
959 
960 	if (p_buf)
961 		strncpy(p_buf, buf, p_buf_len);
962 	else
963 		pr_debug("%s", buf);
964 
965 	return ret;
966 }
967 
968 int
969 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
970 {
971 	static const char hex_str[] = "0123456789abcdef";
972 	int j = 0, i = 4; /* offset to start of the identifer */
973 
974 	/*
975 	 * The VPD Code Set (encoding)
976 	 *
977 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
978 	 */
979 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
980 	switch (vpd->device_identifier_code_set) {
981 	case 0x01: /* Binary */
982 		vpd->device_identifier[j++] =
983 				hex_str[vpd->device_identifier_type];
984 		while (i < (4 + page_83[3])) {
985 			vpd->device_identifier[j++] =
986 				hex_str[(page_83[i] & 0xf0) >> 4];
987 			vpd->device_identifier[j++] =
988 				hex_str[page_83[i] & 0x0f];
989 			i++;
990 		}
991 		break;
992 	case 0x02: /* ASCII */
993 	case 0x03: /* UTF-8 */
994 		while (i < (4 + page_83[3]))
995 			vpd->device_identifier[j++] = page_83[i++];
996 		break;
997 	default:
998 		break;
999 	}
1000 
1001 	return transport_dump_vpd_ident(vpd, NULL, 0);
1002 }
1003 EXPORT_SYMBOL(transport_set_vpd_ident);
1004 
1005 static void core_setup_task_attr_emulation(struct se_device *dev)
1006 {
1007 	/*
1008 	 * If this device is from Target_Core_Mod/pSCSI, disable the
1009 	 * SAM Task Attribute emulation.
1010 	 *
1011 	 * This is currently not available in upsream Linux/SCSI Target
1012 	 * mode code, and is assumed to be disabled while using TCM/pSCSI.
1013 	 */
1014 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
1015 		dev->dev_task_attr_type = SAM_TASK_ATTR_PASSTHROUGH;
1016 		return;
1017 	}
1018 
1019 	dev->dev_task_attr_type = SAM_TASK_ATTR_EMULATED;
1020 	pr_debug("%s: Using SAM_TASK_ATTR_EMULATED for SPC: 0x%02x"
1021 		" device\n", dev->transport->name,
1022 		dev->transport->get_device_rev(dev));
1023 }
1024 
1025 static void scsi_dump_inquiry(struct se_device *dev)
1026 {
1027 	struct t10_wwn *wwn = &dev->se_sub_dev->t10_wwn;
1028 	char buf[17];
1029 	int i, device_type;
1030 	/*
1031 	 * Print Linux/SCSI style INQUIRY formatting to the kernel ring buffer
1032 	 */
1033 	for (i = 0; i < 8; i++)
1034 		if (wwn->vendor[i] >= 0x20)
1035 			buf[i] = wwn->vendor[i];
1036 		else
1037 			buf[i] = ' ';
1038 	buf[i] = '\0';
1039 	pr_debug("  Vendor: %s\n", buf);
1040 
1041 	for (i = 0; i < 16; i++)
1042 		if (wwn->model[i] >= 0x20)
1043 			buf[i] = wwn->model[i];
1044 		else
1045 			buf[i] = ' ';
1046 	buf[i] = '\0';
1047 	pr_debug("  Model: %s\n", buf);
1048 
1049 	for (i = 0; i < 4; i++)
1050 		if (wwn->revision[i] >= 0x20)
1051 			buf[i] = wwn->revision[i];
1052 		else
1053 			buf[i] = ' ';
1054 	buf[i] = '\0';
1055 	pr_debug("  Revision: %s\n", buf);
1056 
1057 	device_type = dev->transport->get_device_type(dev);
1058 	pr_debug("  Type:   %s ", scsi_device_type(device_type));
1059 	pr_debug("                 ANSI SCSI revision: %02x\n",
1060 				dev->transport->get_device_rev(dev));
1061 }
1062 
1063 struct se_device *transport_add_device_to_core_hba(
1064 	struct se_hba *hba,
1065 	struct se_subsystem_api *transport,
1066 	struct se_subsystem_dev *se_dev,
1067 	u32 device_flags,
1068 	void *transport_dev,
1069 	struct se_dev_limits *dev_limits,
1070 	const char *inquiry_prod,
1071 	const char *inquiry_rev)
1072 {
1073 	int force_pt;
1074 	struct se_device  *dev;
1075 
1076 	dev = kzalloc(sizeof(struct se_device), GFP_KERNEL);
1077 	if (!dev) {
1078 		pr_err("Unable to allocate memory for se_dev_t\n");
1079 		return NULL;
1080 	}
1081 
1082 	dev->dev_flags		= device_flags;
1083 	dev->dev_status		|= TRANSPORT_DEVICE_DEACTIVATED;
1084 	dev->dev_ptr		= transport_dev;
1085 	dev->se_hba		= hba;
1086 	dev->se_sub_dev		= se_dev;
1087 	dev->transport		= transport;
1088 	INIT_LIST_HEAD(&dev->dev_list);
1089 	INIT_LIST_HEAD(&dev->dev_sep_list);
1090 	INIT_LIST_HEAD(&dev->dev_tmr_list);
1091 	INIT_LIST_HEAD(&dev->delayed_cmd_list);
1092 	INIT_LIST_HEAD(&dev->state_list);
1093 	INIT_LIST_HEAD(&dev->qf_cmd_list);
1094 	spin_lock_init(&dev->execute_task_lock);
1095 	spin_lock_init(&dev->delayed_cmd_lock);
1096 	spin_lock_init(&dev->dev_reservation_lock);
1097 	spin_lock_init(&dev->dev_status_lock);
1098 	spin_lock_init(&dev->se_port_lock);
1099 	spin_lock_init(&dev->se_tmr_lock);
1100 	spin_lock_init(&dev->qf_cmd_lock);
1101 	atomic_set(&dev->dev_ordered_id, 0);
1102 
1103 	se_dev_set_default_attribs(dev, dev_limits);
1104 
1105 	dev->dev_index = scsi_get_new_index(SCSI_DEVICE_INDEX);
1106 	dev->creation_time = get_jiffies_64();
1107 	spin_lock_init(&dev->stats_lock);
1108 
1109 	spin_lock(&hba->device_lock);
1110 	list_add_tail(&dev->dev_list, &hba->hba_dev_list);
1111 	hba->dev_count++;
1112 	spin_unlock(&hba->device_lock);
1113 	/*
1114 	 * Setup the SAM Task Attribute emulation for struct se_device
1115 	 */
1116 	core_setup_task_attr_emulation(dev);
1117 	/*
1118 	 * Force PR and ALUA passthrough emulation with internal object use.
1119 	 */
1120 	force_pt = (hba->hba_flags & HBA_FLAGS_INTERNAL_USE);
1121 	/*
1122 	 * Setup the Reservations infrastructure for struct se_device
1123 	 */
1124 	core_setup_reservations(dev, force_pt);
1125 	/*
1126 	 * Setup the Asymmetric Logical Unit Assignment for struct se_device
1127 	 */
1128 	if (core_setup_alua(dev, force_pt) < 0)
1129 		goto err_dev_list;
1130 
1131 	/*
1132 	 * Startup the struct se_device processing thread
1133 	 */
1134 	dev->tmr_wq = alloc_workqueue("tmr-%s", WQ_MEM_RECLAIM | WQ_UNBOUND, 1,
1135 				      dev->transport->name);
1136 	if (!dev->tmr_wq) {
1137 		pr_err("Unable to create tmr workqueue for %s\n",
1138 			dev->transport->name);
1139 		goto err_dev_list;
1140 	}
1141 	/*
1142 	 * Setup work_queue for QUEUE_FULL
1143 	 */
1144 	INIT_WORK(&dev->qf_work_queue, target_qf_do_work);
1145 	/*
1146 	 * Preload the initial INQUIRY const values if we are doing
1147 	 * anything virtual (IBLOCK, FILEIO, RAMDISK), but not for TCM/pSCSI
1148 	 * passthrough because this is being provided by the backend LLD.
1149 	 * This is required so that transport_get_inquiry() copies these
1150 	 * originals once back into DEV_T10_WWN(dev) for the virtual device
1151 	 * setup.
1152 	 */
1153 	if (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV) {
1154 		if (!inquiry_prod || !inquiry_rev) {
1155 			pr_err("All non TCM/pSCSI plugins require"
1156 				" INQUIRY consts\n");
1157 			goto err_wq;
1158 		}
1159 
1160 		strncpy(&dev->se_sub_dev->t10_wwn.vendor[0], "LIO-ORG", 8);
1161 		strncpy(&dev->se_sub_dev->t10_wwn.model[0], inquiry_prod, 16);
1162 		strncpy(&dev->se_sub_dev->t10_wwn.revision[0], inquiry_rev, 4);
1163 	}
1164 	scsi_dump_inquiry(dev);
1165 
1166 	return dev;
1167 
1168 err_wq:
1169 	destroy_workqueue(dev->tmr_wq);
1170 err_dev_list:
1171 	spin_lock(&hba->device_lock);
1172 	list_del(&dev->dev_list);
1173 	hba->dev_count--;
1174 	spin_unlock(&hba->device_lock);
1175 
1176 	se_release_vpd_for_dev(dev);
1177 
1178 	kfree(dev);
1179 
1180 	return NULL;
1181 }
1182 EXPORT_SYMBOL(transport_add_device_to_core_hba);
1183 
1184 int target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1185 {
1186 	struct se_device *dev = cmd->se_dev;
1187 
1188 	if (cmd->unknown_data_length) {
1189 		cmd->data_length = size;
1190 	} else if (size != cmd->data_length) {
1191 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1192 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1193 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1194 				cmd->data_length, size, cmd->t_task_cdb[0]);
1195 
1196 		if (cmd->data_direction == DMA_TO_DEVICE) {
1197 			pr_err("Rejecting underflow/overflow"
1198 					" WRITE data\n");
1199 			goto out_invalid_cdb_field;
1200 		}
1201 		/*
1202 		 * Reject READ_* or WRITE_* with overflow/underflow for
1203 		 * type SCF_SCSI_DATA_CDB.
1204 		 */
1205 		if (dev->se_sub_dev->se_dev_attrib.block_size != 512)  {
1206 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1207 				" CDB on non 512-byte sector setup subsystem"
1208 				" plugin: %s\n", dev->transport->name);
1209 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1210 			goto out_invalid_cdb_field;
1211 		}
1212 		/*
1213 		 * For the overflow case keep the existing fabric provided
1214 		 * ->data_length.  Otherwise for the underflow case, reset
1215 		 * ->data_length to the smaller SCSI expected data transfer
1216 		 * length.
1217 		 */
1218 		if (size > cmd->data_length) {
1219 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1220 			cmd->residual_count = (size - cmd->data_length);
1221 		} else {
1222 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1223 			cmd->residual_count = (cmd->data_length - size);
1224 			cmd->data_length = size;
1225 		}
1226 	}
1227 
1228 	return 0;
1229 
1230 out_invalid_cdb_field:
1231 	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1232 	cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1233 	return -EINVAL;
1234 }
1235 
1236 /*
1237  * Used by fabric modules containing a local struct se_cmd within their
1238  * fabric dependent per I/O descriptor.
1239  */
1240 void transport_init_se_cmd(
1241 	struct se_cmd *cmd,
1242 	struct target_core_fabric_ops *tfo,
1243 	struct se_session *se_sess,
1244 	u32 data_length,
1245 	int data_direction,
1246 	int task_attr,
1247 	unsigned char *sense_buffer)
1248 {
1249 	INIT_LIST_HEAD(&cmd->se_lun_node);
1250 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1251 	INIT_LIST_HEAD(&cmd->se_qf_node);
1252 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1253 	INIT_LIST_HEAD(&cmd->state_list);
1254 	init_completion(&cmd->transport_lun_fe_stop_comp);
1255 	init_completion(&cmd->transport_lun_stop_comp);
1256 	init_completion(&cmd->t_transport_stop_comp);
1257 	init_completion(&cmd->cmd_wait_comp);
1258 	init_completion(&cmd->task_stop_comp);
1259 	spin_lock_init(&cmd->t_state_lock);
1260 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1261 
1262 	cmd->se_tfo = tfo;
1263 	cmd->se_sess = se_sess;
1264 	cmd->data_length = data_length;
1265 	cmd->data_direction = data_direction;
1266 	cmd->sam_task_attr = task_attr;
1267 	cmd->sense_buffer = sense_buffer;
1268 
1269 	cmd->state_active = false;
1270 }
1271 EXPORT_SYMBOL(transport_init_se_cmd);
1272 
1273 static int transport_check_alloc_task_attr(struct se_cmd *cmd)
1274 {
1275 	/*
1276 	 * Check if SAM Task Attribute emulation is enabled for this
1277 	 * struct se_device storage object
1278 	 */
1279 	if (cmd->se_dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED)
1280 		return 0;
1281 
1282 	if (cmd->sam_task_attr == MSG_ACA_TAG) {
1283 		pr_debug("SAM Task Attribute ACA"
1284 			" emulation is not supported\n");
1285 		return -EINVAL;
1286 	}
1287 	/*
1288 	 * Used to determine when ORDERED commands should go from
1289 	 * Dormant to Active status.
1290 	 */
1291 	cmd->se_ordered_id = atomic_inc_return(&cmd->se_dev->dev_ordered_id);
1292 	smp_mb__after_atomic_inc();
1293 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1294 			cmd->se_ordered_id, cmd->sam_task_attr,
1295 			cmd->se_dev->transport->name);
1296 	return 0;
1297 }
1298 
1299 /*	target_setup_cmd_from_cdb():
1300  *
1301  *	Called from fabric RX Thread.
1302  */
1303 int target_setup_cmd_from_cdb(
1304 	struct se_cmd *cmd,
1305 	unsigned char *cdb)
1306 {
1307 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
1308 	u32 pr_reg_type = 0;
1309 	u8 alua_ascq = 0;
1310 	unsigned long flags;
1311 	int ret;
1312 
1313 	/*
1314 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1315 	 * for VARIABLE_LENGTH_CMD
1316 	 */
1317 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1318 		pr_err("Received SCSI CDB with command_size: %d that"
1319 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1320 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1321 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1322 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1323 		return -EINVAL;
1324 	}
1325 	/*
1326 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1327 	 * allocate the additional extended CDB buffer now..  Otherwise
1328 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1329 	 */
1330 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1331 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1332 						GFP_KERNEL);
1333 		if (!cmd->t_task_cdb) {
1334 			pr_err("Unable to allocate cmd->t_task_cdb"
1335 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1336 				scsi_command_size(cdb),
1337 				(unsigned long)sizeof(cmd->__t_task_cdb));
1338 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1339 			cmd->scsi_sense_reason =
1340 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1341 			return -ENOMEM;
1342 		}
1343 	} else
1344 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1345 	/*
1346 	 * Copy the original CDB into cmd->
1347 	 */
1348 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1349 
1350 	/*
1351 	 * Check for an existing UNIT ATTENTION condition
1352 	 */
1353 	if (core_scsi3_ua_check(cmd, cdb) < 0) {
1354 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1355 		cmd->scsi_sense_reason = TCM_CHECK_CONDITION_UNIT_ATTENTION;
1356 		return -EINVAL;
1357 	}
1358 
1359 	ret = su_dev->t10_alua.alua_state_check(cmd, cdb, &alua_ascq);
1360 	if (ret != 0) {
1361 		/*
1362 		 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
1363 		 * The ALUA additional sense code qualifier (ASCQ) is determined
1364 		 * by the ALUA primary or secondary access state..
1365 		 */
1366 		if (ret > 0) {
1367 			pr_debug("[%s]: ALUA TG Port not available, "
1368 				"SenseKey: NOT_READY, ASC/ASCQ: "
1369 				"0x04/0x%02x\n",
1370 				cmd->se_tfo->get_fabric_name(), alua_ascq);
1371 
1372 			transport_set_sense_codes(cmd, 0x04, alua_ascq);
1373 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1374 			cmd->scsi_sense_reason = TCM_CHECK_CONDITION_NOT_READY;
1375 			return -EINVAL;
1376 		}
1377 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1378 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1379 		return -EINVAL;
1380 	}
1381 
1382 	/*
1383 	 * Check status for SPC-3 Persistent Reservations
1384 	 */
1385 	if (su_dev->t10_pr.pr_ops.t10_reservation_check(cmd, &pr_reg_type)) {
1386 		if (su_dev->t10_pr.pr_ops.t10_seq_non_holder(
1387 					cmd, cdb, pr_reg_type) != 0) {
1388 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1389 			cmd->se_cmd_flags |= SCF_SCSI_RESERVATION_CONFLICT;
1390 			cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1391 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
1392 			return -EBUSY;
1393 		}
1394 		/*
1395 		 * This means the CDB is allowed for the SCSI Initiator port
1396 		 * when said port is *NOT* holding the legacy SPC-2 or
1397 		 * SPC-3 Persistent Reservation.
1398 		 */
1399 	}
1400 
1401 	ret = cmd->se_dev->transport->parse_cdb(cmd);
1402 	if (ret < 0)
1403 		return ret;
1404 
1405 	spin_lock_irqsave(&cmd->t_state_lock, flags);
1406 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1407 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1408 
1409 	/*
1410 	 * Check for SAM Task Attribute Emulation
1411 	 */
1412 	if (transport_check_alloc_task_attr(cmd) < 0) {
1413 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1414 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1415 		return -EINVAL;
1416 	}
1417 	spin_lock(&cmd->se_lun->lun_sep_lock);
1418 	if (cmd->se_lun->lun_sep)
1419 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1420 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1421 	return 0;
1422 }
1423 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1424 
1425 /*
1426  * Used by fabric module frontends to queue tasks directly.
1427  * Many only be used from process context only
1428  */
1429 int transport_handle_cdb_direct(
1430 	struct se_cmd *cmd)
1431 {
1432 	int ret;
1433 
1434 	if (!cmd->se_lun) {
1435 		dump_stack();
1436 		pr_err("cmd->se_lun is NULL\n");
1437 		return -EINVAL;
1438 	}
1439 	if (in_interrupt()) {
1440 		dump_stack();
1441 		pr_err("transport_generic_handle_cdb cannot be called"
1442 				" from interrupt context\n");
1443 		return -EINVAL;
1444 	}
1445 	/*
1446 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1447 	 * outstanding descriptors are handled correctly during shutdown via
1448 	 * transport_wait_for_tasks()
1449 	 *
1450 	 * Also, we don't take cmd->t_state_lock here as we only expect
1451 	 * this to be called for initial descriptor submission.
1452 	 */
1453 	cmd->t_state = TRANSPORT_NEW_CMD;
1454 	cmd->transport_state |= CMD_T_ACTIVE;
1455 
1456 	/*
1457 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1458 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1459 	 * and call transport_generic_request_failure() if necessary..
1460 	 */
1461 	ret = transport_generic_new_cmd(cmd);
1462 	if (ret < 0)
1463 		transport_generic_request_failure(cmd);
1464 
1465 	return 0;
1466 }
1467 EXPORT_SYMBOL(transport_handle_cdb_direct);
1468 
1469 /**
1470  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1471  *
1472  * @se_cmd: command descriptor to submit
1473  * @se_sess: associated se_sess for endpoint
1474  * @cdb: pointer to SCSI CDB
1475  * @sense: pointer to SCSI sense buffer
1476  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1477  * @data_length: fabric expected data transfer length
1478  * @task_addr: SAM task attribute
1479  * @data_dir: DMA data direction
1480  * @flags: flags for command submission from target_sc_flags_tables
1481  *
1482  * Returns non zero to signal active I/O shutdown failure.  All other
1483  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1484  * but still return zero here.
1485  *
1486  * This may only be called from process context, and also currently
1487  * assumes internal allocation of fabric payload buffer by target-core.
1488  **/
1489 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1490 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1491 		u32 data_length, int task_attr, int data_dir, int flags)
1492 {
1493 	struct se_portal_group *se_tpg;
1494 	int rc;
1495 
1496 	se_tpg = se_sess->se_tpg;
1497 	BUG_ON(!se_tpg);
1498 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1499 	BUG_ON(in_interrupt());
1500 	/*
1501 	 * Initialize se_cmd for target operation.  From this point
1502 	 * exceptions are handled by sending exception status via
1503 	 * target_core_fabric_ops->queue_status() callback
1504 	 */
1505 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1506 				data_length, data_dir, task_attr, sense);
1507 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1508 		se_cmd->unknown_data_length = 1;
1509 	/*
1510 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1511 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1512 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1513 	 * kref_put() to happen during fabric packet acknowledgement.
1514 	 */
1515 	rc = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1516 	if (rc)
1517 		return rc;
1518 	/*
1519 	 * Signal bidirectional data payloads to target-core
1520 	 */
1521 	if (flags & TARGET_SCF_BIDI_OP)
1522 		se_cmd->se_cmd_flags |= SCF_BIDI;
1523 	/*
1524 	 * Locate se_lun pointer and attach it to struct se_cmd
1525 	 */
1526 	if (transport_lookup_cmd_lun(se_cmd, unpacked_lun) < 0) {
1527 		transport_send_check_condition_and_sense(se_cmd,
1528 				se_cmd->scsi_sense_reason, 0);
1529 		target_put_sess_cmd(se_sess, se_cmd);
1530 		return 0;
1531 	}
1532 
1533 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1534 	if (rc != 0) {
1535 		transport_generic_request_failure(se_cmd);
1536 		return 0;
1537 	}
1538 
1539 	/*
1540 	 * Check if we need to delay processing because of ALUA
1541 	 * Active/NonOptimized primary access state..
1542 	 */
1543 	core_alua_check_nonop_delay(se_cmd);
1544 
1545 	transport_handle_cdb_direct(se_cmd);
1546 	return 0;
1547 }
1548 EXPORT_SYMBOL(target_submit_cmd);
1549 
1550 static void target_complete_tmr_failure(struct work_struct *work)
1551 {
1552 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1553 
1554 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1555 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1556 	transport_generic_free_cmd(se_cmd, 0);
1557 }
1558 
1559 /**
1560  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1561  *                     for TMR CDBs
1562  *
1563  * @se_cmd: command descriptor to submit
1564  * @se_sess: associated se_sess for endpoint
1565  * @sense: pointer to SCSI sense buffer
1566  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1567  * @fabric_context: fabric context for TMR req
1568  * @tm_type: Type of TM request
1569  * @gfp: gfp type for caller
1570  * @tag: referenced task tag for TMR_ABORT_TASK
1571  * @flags: submit cmd flags
1572  *
1573  * Callable from all contexts.
1574  **/
1575 
1576 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1577 		unsigned char *sense, u32 unpacked_lun,
1578 		void *fabric_tmr_ptr, unsigned char tm_type,
1579 		gfp_t gfp, unsigned int tag, int flags)
1580 {
1581 	struct se_portal_group *se_tpg;
1582 	int ret;
1583 
1584 	se_tpg = se_sess->se_tpg;
1585 	BUG_ON(!se_tpg);
1586 
1587 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1588 			      0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1589 	/*
1590 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1591 	 * allocation failure.
1592 	 */
1593 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1594 	if (ret < 0)
1595 		return -ENOMEM;
1596 
1597 	if (tm_type == TMR_ABORT_TASK)
1598 		se_cmd->se_tmr_req->ref_task_tag = tag;
1599 
1600 	/* See target_submit_cmd for commentary */
1601 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1602 	if (ret) {
1603 		core_tmr_release_req(se_cmd->se_tmr_req);
1604 		return ret;
1605 	}
1606 
1607 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1608 	if (ret) {
1609 		/*
1610 		 * For callback during failure handling, push this work off
1611 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1612 		 */
1613 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1614 		schedule_work(&se_cmd->work);
1615 		return 0;
1616 	}
1617 	transport_generic_handle_tmr(se_cmd);
1618 	return 0;
1619 }
1620 EXPORT_SYMBOL(target_submit_tmr);
1621 
1622 /*
1623  * If the cmd is active, request it to be stopped and sleep until it
1624  * has completed.
1625  */
1626 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1627 {
1628 	bool was_active = false;
1629 
1630 	if (cmd->transport_state & CMD_T_BUSY) {
1631 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1632 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1633 
1634 		pr_debug("cmd %p waiting to complete\n", cmd);
1635 		wait_for_completion(&cmd->task_stop_comp);
1636 		pr_debug("cmd %p stopped successfully\n", cmd);
1637 
1638 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1639 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1640 		cmd->transport_state &= ~CMD_T_BUSY;
1641 		was_active = true;
1642 	}
1643 
1644 	return was_active;
1645 }
1646 
1647 /*
1648  * Handle SAM-esque emulation for generic transport request failures.
1649  */
1650 void transport_generic_request_failure(struct se_cmd *cmd)
1651 {
1652 	int ret = 0;
1653 
1654 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1655 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1656 		cmd->t_task_cdb[0]);
1657 	pr_debug("-----[ i_state: %d t_state: %d scsi_sense_reason: %d\n",
1658 		cmd->se_tfo->get_cmd_state(cmd),
1659 		cmd->t_state, cmd->scsi_sense_reason);
1660 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1661 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1662 		(cmd->transport_state & CMD_T_STOP) != 0,
1663 		(cmd->transport_state & CMD_T_SENT) != 0);
1664 
1665 	/*
1666 	 * For SAM Task Attribute emulation for failed struct se_cmd
1667 	 */
1668 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1669 		transport_complete_task_attr(cmd);
1670 
1671 	switch (cmd->scsi_sense_reason) {
1672 	case TCM_NON_EXISTENT_LUN:
1673 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1674 	case TCM_INVALID_CDB_FIELD:
1675 	case TCM_INVALID_PARAMETER_LIST:
1676 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1677 	case TCM_UNKNOWN_MODE_PAGE:
1678 	case TCM_WRITE_PROTECTED:
1679 	case TCM_ADDRESS_OUT_OF_RANGE:
1680 	case TCM_CHECK_CONDITION_ABORT_CMD:
1681 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1682 	case TCM_CHECK_CONDITION_NOT_READY:
1683 		break;
1684 	case TCM_RESERVATION_CONFLICT:
1685 		/*
1686 		 * No SENSE Data payload for this case, set SCSI Status
1687 		 * and queue the response to $FABRIC_MOD.
1688 		 *
1689 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1690 		 */
1691 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1692 		/*
1693 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1694 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1695 		 * CONFLICT STATUS.
1696 		 *
1697 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1698 		 */
1699 		if (cmd->se_sess &&
1700 		    cmd->se_dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl == 2)
1701 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1702 				cmd->orig_fe_lun, 0x2C,
1703 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1704 
1705 		ret = cmd->se_tfo->queue_status(cmd);
1706 		if (ret == -EAGAIN || ret == -ENOMEM)
1707 			goto queue_full;
1708 		goto check_stop;
1709 	default:
1710 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1711 			cmd->t_task_cdb[0], cmd->scsi_sense_reason);
1712 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1713 		break;
1714 	}
1715 
1716 	ret = transport_send_check_condition_and_sense(cmd,
1717 			cmd->scsi_sense_reason, 0);
1718 	if (ret == -EAGAIN || ret == -ENOMEM)
1719 		goto queue_full;
1720 
1721 check_stop:
1722 	transport_lun_remove_cmd(cmd);
1723 	if (!transport_cmd_check_stop_to_fabric(cmd))
1724 		;
1725 	return;
1726 
1727 queue_full:
1728 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1729 	transport_handle_queue_full(cmd, cmd->se_dev);
1730 }
1731 EXPORT_SYMBOL(transport_generic_request_failure);
1732 
1733 static void __target_execute_cmd(struct se_cmd *cmd)
1734 {
1735 	int error = 0;
1736 
1737 	spin_lock_irq(&cmd->t_state_lock);
1738 	cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
1739 	spin_unlock_irq(&cmd->t_state_lock);
1740 
1741 	if (cmd->execute_cmd)
1742 		error = cmd->execute_cmd(cmd);
1743 
1744 	if (error) {
1745 		spin_lock_irq(&cmd->t_state_lock);
1746 		cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1747 		spin_unlock_irq(&cmd->t_state_lock);
1748 
1749 		transport_generic_request_failure(cmd);
1750 	}
1751 }
1752 
1753 void target_execute_cmd(struct se_cmd *cmd)
1754 {
1755 	struct se_device *dev = cmd->se_dev;
1756 
1757 	/*
1758 	 * If the received CDB has aleady been aborted stop processing it here.
1759 	 */
1760 	if (transport_check_aborted_status(cmd, 1))
1761 		return;
1762 
1763 	/*
1764 	 * Determine if IOCTL context caller in requesting the stopping of this
1765 	 * command for LUN shutdown purposes.
1766 	 */
1767 	spin_lock_irq(&cmd->t_state_lock);
1768 	if (cmd->transport_state & CMD_T_LUN_STOP) {
1769 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
1770 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
1771 
1772 		cmd->transport_state &= ~CMD_T_ACTIVE;
1773 		spin_unlock_irq(&cmd->t_state_lock);
1774 		complete(&cmd->transport_lun_stop_comp);
1775 		return;
1776 	}
1777 	/*
1778 	 * Determine if frontend context caller is requesting the stopping of
1779 	 * this command for frontend exceptions.
1780 	 */
1781 	if (cmd->transport_state & CMD_T_STOP) {
1782 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1783 			__func__, __LINE__,
1784 			cmd->se_tfo->get_task_tag(cmd));
1785 
1786 		spin_unlock_irq(&cmd->t_state_lock);
1787 		complete(&cmd->t_transport_stop_comp);
1788 		return;
1789 	}
1790 
1791 	cmd->t_state = TRANSPORT_PROCESSING;
1792 	spin_unlock_irq(&cmd->t_state_lock);
1793 
1794 	if (dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED)
1795 		goto execute;
1796 
1797 	/*
1798 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1799 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1800 	 */
1801 	switch (cmd->sam_task_attr) {
1802 	case MSG_HEAD_TAG:
1803 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1804 			 "se_ordered_id: %u\n",
1805 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1806 		goto execute;
1807 	case MSG_ORDERED_TAG:
1808 		atomic_inc(&dev->dev_ordered_sync);
1809 		smp_mb__after_atomic_inc();
1810 
1811 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1812 			 " se_ordered_id: %u\n",
1813 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1814 
1815 		/*
1816 		 * Execute an ORDERED command if no other older commands
1817 		 * exist that need to be completed first.
1818 		 */
1819 		if (!atomic_read(&dev->simple_cmds))
1820 			goto execute;
1821 		break;
1822 	default:
1823 		/*
1824 		 * For SIMPLE and UNTAGGED Task Attribute commands
1825 		 */
1826 		atomic_inc(&dev->simple_cmds);
1827 		smp_mb__after_atomic_inc();
1828 		break;
1829 	}
1830 
1831 	if (atomic_read(&dev->dev_ordered_sync) != 0) {
1832 		spin_lock(&dev->delayed_cmd_lock);
1833 		list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1834 		spin_unlock(&dev->delayed_cmd_lock);
1835 
1836 		pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1837 			" delayed CMD list, se_ordered_id: %u\n",
1838 			cmd->t_task_cdb[0], cmd->sam_task_attr,
1839 			cmd->se_ordered_id);
1840 		return;
1841 	}
1842 
1843 execute:
1844 	/*
1845 	 * Otherwise, no ORDERED task attributes exist..
1846 	 */
1847 	__target_execute_cmd(cmd);
1848 }
1849 EXPORT_SYMBOL(target_execute_cmd);
1850 
1851 /*
1852  * Process all commands up to the last received ORDERED task attribute which
1853  * requires another blocking boundary
1854  */
1855 static void target_restart_delayed_cmds(struct se_device *dev)
1856 {
1857 	for (;;) {
1858 		struct se_cmd *cmd;
1859 
1860 		spin_lock(&dev->delayed_cmd_lock);
1861 		if (list_empty(&dev->delayed_cmd_list)) {
1862 			spin_unlock(&dev->delayed_cmd_lock);
1863 			break;
1864 		}
1865 
1866 		cmd = list_entry(dev->delayed_cmd_list.next,
1867 				 struct se_cmd, se_delayed_node);
1868 		list_del(&cmd->se_delayed_node);
1869 		spin_unlock(&dev->delayed_cmd_lock);
1870 
1871 		__target_execute_cmd(cmd);
1872 
1873 		if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1874 			break;
1875 	}
1876 }
1877 
1878 /*
1879  * Called from I/O completion to determine which dormant/delayed
1880  * and ordered cmds need to have their tasks added to the execution queue.
1881  */
1882 static void transport_complete_task_attr(struct se_cmd *cmd)
1883 {
1884 	struct se_device *dev = cmd->se_dev;
1885 
1886 	if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1887 		atomic_dec(&dev->simple_cmds);
1888 		smp_mb__after_atomic_dec();
1889 		dev->dev_cur_ordered_id++;
1890 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1891 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1892 			cmd->se_ordered_id);
1893 	} else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1894 		dev->dev_cur_ordered_id++;
1895 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1896 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1897 			cmd->se_ordered_id);
1898 	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1899 		atomic_dec(&dev->dev_ordered_sync);
1900 		smp_mb__after_atomic_dec();
1901 
1902 		dev->dev_cur_ordered_id++;
1903 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1904 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1905 	}
1906 
1907 	target_restart_delayed_cmds(dev);
1908 }
1909 
1910 static void transport_complete_qf(struct se_cmd *cmd)
1911 {
1912 	int ret = 0;
1913 
1914 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1915 		transport_complete_task_attr(cmd);
1916 
1917 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1918 		ret = cmd->se_tfo->queue_status(cmd);
1919 		if (ret)
1920 			goto out;
1921 	}
1922 
1923 	switch (cmd->data_direction) {
1924 	case DMA_FROM_DEVICE:
1925 		ret = cmd->se_tfo->queue_data_in(cmd);
1926 		break;
1927 	case DMA_TO_DEVICE:
1928 		if (cmd->t_bidi_data_sg) {
1929 			ret = cmd->se_tfo->queue_data_in(cmd);
1930 			if (ret < 0)
1931 				break;
1932 		}
1933 		/* Fall through for DMA_TO_DEVICE */
1934 	case DMA_NONE:
1935 		ret = cmd->se_tfo->queue_status(cmd);
1936 		break;
1937 	default:
1938 		break;
1939 	}
1940 
1941 out:
1942 	if (ret < 0) {
1943 		transport_handle_queue_full(cmd, cmd->se_dev);
1944 		return;
1945 	}
1946 	transport_lun_remove_cmd(cmd);
1947 	transport_cmd_check_stop_to_fabric(cmd);
1948 }
1949 
1950 static void transport_handle_queue_full(
1951 	struct se_cmd *cmd,
1952 	struct se_device *dev)
1953 {
1954 	spin_lock_irq(&dev->qf_cmd_lock);
1955 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1956 	atomic_inc(&dev->dev_qf_count);
1957 	smp_mb__after_atomic_inc();
1958 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1959 
1960 	schedule_work(&cmd->se_dev->qf_work_queue);
1961 }
1962 
1963 static void target_complete_ok_work(struct work_struct *work)
1964 {
1965 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1966 	int ret;
1967 
1968 	/*
1969 	 * Check if we need to move delayed/dormant tasks from cmds on the
1970 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1971 	 * Attribute.
1972 	 */
1973 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1974 		transport_complete_task_attr(cmd);
1975 	/*
1976 	 * Check to schedule QUEUE_FULL work, or execute an existing
1977 	 * cmd->transport_qf_callback()
1978 	 */
1979 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1980 		schedule_work(&cmd->se_dev->qf_work_queue);
1981 
1982 	/*
1983 	 * Check if we need to send a sense buffer from
1984 	 * the struct se_cmd in question.
1985 	 */
1986 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1987 		WARN_ON(!cmd->scsi_status);
1988 		ret = transport_send_check_condition_and_sense(
1989 					cmd, 0, 1);
1990 		if (ret == -EAGAIN || ret == -ENOMEM)
1991 			goto queue_full;
1992 
1993 		transport_lun_remove_cmd(cmd);
1994 		transport_cmd_check_stop_to_fabric(cmd);
1995 		return;
1996 	}
1997 	/*
1998 	 * Check for a callback, used by amongst other things
1999 	 * XDWRITE_READ_10 emulation.
2000 	 */
2001 	if (cmd->transport_complete_callback)
2002 		cmd->transport_complete_callback(cmd);
2003 
2004 	switch (cmd->data_direction) {
2005 	case DMA_FROM_DEVICE:
2006 		spin_lock(&cmd->se_lun->lun_sep_lock);
2007 		if (cmd->se_lun->lun_sep) {
2008 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2009 					cmd->data_length;
2010 		}
2011 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2012 
2013 		ret = cmd->se_tfo->queue_data_in(cmd);
2014 		if (ret == -EAGAIN || ret == -ENOMEM)
2015 			goto queue_full;
2016 		break;
2017 	case DMA_TO_DEVICE:
2018 		spin_lock(&cmd->se_lun->lun_sep_lock);
2019 		if (cmd->se_lun->lun_sep) {
2020 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2021 				cmd->data_length;
2022 		}
2023 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2024 		/*
2025 		 * Check if we need to send READ payload for BIDI-COMMAND
2026 		 */
2027 		if (cmd->t_bidi_data_sg) {
2028 			spin_lock(&cmd->se_lun->lun_sep_lock);
2029 			if (cmd->se_lun->lun_sep) {
2030 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2031 					cmd->data_length;
2032 			}
2033 			spin_unlock(&cmd->se_lun->lun_sep_lock);
2034 			ret = cmd->se_tfo->queue_data_in(cmd);
2035 			if (ret == -EAGAIN || ret == -ENOMEM)
2036 				goto queue_full;
2037 			break;
2038 		}
2039 		/* Fall through for DMA_TO_DEVICE */
2040 	case DMA_NONE:
2041 		ret = cmd->se_tfo->queue_status(cmd);
2042 		if (ret == -EAGAIN || ret == -ENOMEM)
2043 			goto queue_full;
2044 		break;
2045 	default:
2046 		break;
2047 	}
2048 
2049 	transport_lun_remove_cmd(cmd);
2050 	transport_cmd_check_stop_to_fabric(cmd);
2051 	return;
2052 
2053 queue_full:
2054 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2055 		" data_direction: %d\n", cmd, cmd->data_direction);
2056 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2057 	transport_handle_queue_full(cmd, cmd->se_dev);
2058 }
2059 
2060 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2061 {
2062 	struct scatterlist *sg;
2063 	int count;
2064 
2065 	for_each_sg(sgl, sg, nents, count)
2066 		__free_page(sg_page(sg));
2067 
2068 	kfree(sgl);
2069 }
2070 
2071 static inline void transport_free_pages(struct se_cmd *cmd)
2072 {
2073 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
2074 		return;
2075 
2076 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2077 	cmd->t_data_sg = NULL;
2078 	cmd->t_data_nents = 0;
2079 
2080 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2081 	cmd->t_bidi_data_sg = NULL;
2082 	cmd->t_bidi_data_nents = 0;
2083 }
2084 
2085 /**
2086  * transport_release_cmd - free a command
2087  * @cmd:       command to free
2088  *
2089  * This routine unconditionally frees a command, and reference counting
2090  * or list removal must be done in the caller.
2091  */
2092 static void transport_release_cmd(struct se_cmd *cmd)
2093 {
2094 	BUG_ON(!cmd->se_tfo);
2095 
2096 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2097 		core_tmr_release_req(cmd->se_tmr_req);
2098 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2099 		kfree(cmd->t_task_cdb);
2100 	/*
2101 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2102 	 * the kref and call ->release_cmd() in kref callback.
2103 	 */
2104 	 if (cmd->check_release != 0) {
2105 		target_put_sess_cmd(cmd->se_sess, cmd);
2106 		return;
2107 	}
2108 	cmd->se_tfo->release_cmd(cmd);
2109 }
2110 
2111 /**
2112  * transport_put_cmd - release a reference to a command
2113  * @cmd:       command to release
2114  *
2115  * This routine releases our reference to the command and frees it if possible.
2116  */
2117 static void transport_put_cmd(struct se_cmd *cmd)
2118 {
2119 	unsigned long flags;
2120 
2121 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2122 	if (atomic_read(&cmd->t_fe_count)) {
2123 		if (!atomic_dec_and_test(&cmd->t_fe_count))
2124 			goto out_busy;
2125 	}
2126 
2127 	if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
2128 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2129 		target_remove_from_state_list(cmd);
2130 	}
2131 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2132 
2133 	transport_free_pages(cmd);
2134 	transport_release_cmd(cmd);
2135 	return;
2136 out_busy:
2137 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2138 }
2139 
2140 /*
2141  * transport_generic_map_mem_to_cmd - Use fabric-alloced pages instead of
2142  * allocating in the core.
2143  * @cmd:  Associated se_cmd descriptor
2144  * @mem:  SGL style memory for TCM WRITE / READ
2145  * @sg_mem_num: Number of SGL elements
2146  * @mem_bidi_in: SGL style memory for TCM BIDI READ
2147  * @sg_mem_bidi_num: Number of BIDI READ SGL elements
2148  *
2149  * Return: nonzero return cmd was rejected for -ENOMEM or inproper usage
2150  * of parameters.
2151  */
2152 int transport_generic_map_mem_to_cmd(
2153 	struct se_cmd *cmd,
2154 	struct scatterlist *sgl,
2155 	u32 sgl_count,
2156 	struct scatterlist *sgl_bidi,
2157 	u32 sgl_bidi_count)
2158 {
2159 	if (!sgl || !sgl_count)
2160 		return 0;
2161 
2162 	/*
2163 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
2164 	 * scatterlists already have been set to follow what the fabric
2165 	 * passes for the original expected data transfer length.
2166 	 */
2167 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
2168 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
2169 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
2170 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
2171 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
2172 		return -EINVAL;
2173 	}
2174 
2175 	cmd->t_data_sg = sgl;
2176 	cmd->t_data_nents = sgl_count;
2177 
2178 	if (sgl_bidi && sgl_bidi_count) {
2179 		cmd->t_bidi_data_sg = sgl_bidi;
2180 		cmd->t_bidi_data_nents = sgl_bidi_count;
2181 	}
2182 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
2183 	return 0;
2184 }
2185 EXPORT_SYMBOL(transport_generic_map_mem_to_cmd);
2186 
2187 void *transport_kmap_data_sg(struct se_cmd *cmd)
2188 {
2189 	struct scatterlist *sg = cmd->t_data_sg;
2190 	struct page **pages;
2191 	int i;
2192 
2193 	/*
2194 	 * We need to take into account a possible offset here for fabrics like
2195 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2196 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2197 	 */
2198 	if (!cmd->t_data_nents)
2199 		return NULL;
2200 
2201 	BUG_ON(!sg);
2202 	if (cmd->t_data_nents == 1)
2203 		return kmap(sg_page(sg)) + sg->offset;
2204 
2205 	/* >1 page. use vmap */
2206 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2207 	if (!pages) {
2208 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2209 		return NULL;
2210 	}
2211 
2212 	/* convert sg[] to pages[] */
2213 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2214 		pages[i] = sg_page(sg);
2215 	}
2216 
2217 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2218 	kfree(pages);
2219 	if (!cmd->t_data_vmap) {
2220 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2221 		return NULL;
2222 	}
2223 
2224 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2225 }
2226 EXPORT_SYMBOL(transport_kmap_data_sg);
2227 
2228 void transport_kunmap_data_sg(struct se_cmd *cmd)
2229 {
2230 	if (!cmd->t_data_nents) {
2231 		return;
2232 	} else if (cmd->t_data_nents == 1) {
2233 		kunmap(sg_page(cmd->t_data_sg));
2234 		return;
2235 	}
2236 
2237 	vunmap(cmd->t_data_vmap);
2238 	cmd->t_data_vmap = NULL;
2239 }
2240 EXPORT_SYMBOL(transport_kunmap_data_sg);
2241 
2242 static int
2243 transport_generic_get_mem(struct se_cmd *cmd)
2244 {
2245 	u32 length = cmd->data_length;
2246 	unsigned int nents;
2247 	struct page *page;
2248 	gfp_t zero_flag;
2249 	int i = 0;
2250 
2251 	nents = DIV_ROUND_UP(length, PAGE_SIZE);
2252 	cmd->t_data_sg = kmalloc(sizeof(struct scatterlist) * nents, GFP_KERNEL);
2253 	if (!cmd->t_data_sg)
2254 		return -ENOMEM;
2255 
2256 	cmd->t_data_nents = nents;
2257 	sg_init_table(cmd->t_data_sg, nents);
2258 
2259 	zero_flag = cmd->se_cmd_flags & SCF_SCSI_DATA_CDB ? 0 : __GFP_ZERO;
2260 
2261 	while (length) {
2262 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2263 		page = alloc_page(GFP_KERNEL | zero_flag);
2264 		if (!page)
2265 			goto out;
2266 
2267 		sg_set_page(&cmd->t_data_sg[i], page, page_len, 0);
2268 		length -= page_len;
2269 		i++;
2270 	}
2271 	return 0;
2272 
2273 out:
2274 	while (i > 0) {
2275 		i--;
2276 		__free_page(sg_page(&cmd->t_data_sg[i]));
2277 	}
2278 	kfree(cmd->t_data_sg);
2279 	cmd->t_data_sg = NULL;
2280 	return -ENOMEM;
2281 }
2282 
2283 /*
2284  * Allocate any required resources to execute the command.  For writes we
2285  * might not have the payload yet, so notify the fabric via a call to
2286  * ->write_pending instead. Otherwise place it on the execution queue.
2287  */
2288 int transport_generic_new_cmd(struct se_cmd *cmd)
2289 {
2290 	int ret = 0;
2291 
2292 	/*
2293 	 * Determine is the TCM fabric module has already allocated physical
2294 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2295 	 * beforehand.
2296 	 */
2297 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2298 	    cmd->data_length) {
2299 		ret = transport_generic_get_mem(cmd);
2300 		if (ret < 0)
2301 			goto out_fail;
2302 	}
2303 	/*
2304 	 * If this command doesn't have any payload and we don't have to call
2305 	 * into the fabric for data transfers, go ahead and complete it right
2306 	 * away.
2307 	 */
2308 	if (!cmd->data_length &&
2309 	    cmd->t_task_cdb[0] != REQUEST_SENSE &&
2310 	    cmd->se_dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV) {
2311 		spin_lock_irq(&cmd->t_state_lock);
2312 		cmd->t_state = TRANSPORT_COMPLETE;
2313 		cmd->transport_state |= CMD_T_ACTIVE;
2314 		spin_unlock_irq(&cmd->t_state_lock);
2315 
2316 		INIT_WORK(&cmd->work, target_complete_ok_work);
2317 		queue_work(target_completion_wq, &cmd->work);
2318 		return 0;
2319 	}
2320 
2321 	atomic_inc(&cmd->t_fe_count);
2322 
2323 	/*
2324 	 * If this command is not a write we can execute it right here,
2325 	 * for write buffers we need to notify the fabric driver first
2326 	 * and let it call back once the write buffers are ready.
2327 	 */
2328 	target_add_to_state_list(cmd);
2329 	if (cmd->data_direction != DMA_TO_DEVICE) {
2330 		target_execute_cmd(cmd);
2331 		return 0;
2332 	}
2333 
2334 	spin_lock_irq(&cmd->t_state_lock);
2335 	cmd->t_state = TRANSPORT_WRITE_PENDING;
2336 	spin_unlock_irq(&cmd->t_state_lock);
2337 
2338 	transport_cmd_check_stop(cmd, false);
2339 
2340 	ret = cmd->se_tfo->write_pending(cmd);
2341 	if (ret == -EAGAIN || ret == -ENOMEM)
2342 		goto queue_full;
2343 
2344 	if (ret < 0)
2345 		return ret;
2346 	return 1;
2347 
2348 out_fail:
2349 	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
2350 	cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2351 	return -EINVAL;
2352 queue_full:
2353 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2354 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2355 	transport_handle_queue_full(cmd, cmd->se_dev);
2356 	return 0;
2357 }
2358 EXPORT_SYMBOL(transport_generic_new_cmd);
2359 
2360 static void transport_write_pending_qf(struct se_cmd *cmd)
2361 {
2362 	int ret;
2363 
2364 	ret = cmd->se_tfo->write_pending(cmd);
2365 	if (ret == -EAGAIN || ret == -ENOMEM) {
2366 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2367 			 cmd);
2368 		transport_handle_queue_full(cmd, cmd->se_dev);
2369 	}
2370 }
2371 
2372 void transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2373 {
2374 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2375 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2376 			 transport_wait_for_tasks(cmd);
2377 
2378 		transport_release_cmd(cmd);
2379 	} else {
2380 		if (wait_for_tasks)
2381 			transport_wait_for_tasks(cmd);
2382 
2383 		core_dec_lacl_count(cmd->se_sess->se_node_acl, cmd);
2384 
2385 		if (cmd->se_lun)
2386 			transport_lun_remove_cmd(cmd);
2387 
2388 		transport_put_cmd(cmd);
2389 	}
2390 }
2391 EXPORT_SYMBOL(transport_generic_free_cmd);
2392 
2393 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2394  * @se_sess:	session to reference
2395  * @se_cmd:	command descriptor to add
2396  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2397  */
2398 static int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2399 			       bool ack_kref)
2400 {
2401 	unsigned long flags;
2402 	int ret = 0;
2403 
2404 	kref_init(&se_cmd->cmd_kref);
2405 	/*
2406 	 * Add a second kref if the fabric caller is expecting to handle
2407 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2408 	 * invocations before se_cmd descriptor release.
2409 	 */
2410 	if (ack_kref == true) {
2411 		kref_get(&se_cmd->cmd_kref);
2412 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2413 	}
2414 
2415 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2416 	if (se_sess->sess_tearing_down) {
2417 		ret = -ESHUTDOWN;
2418 		goto out;
2419 	}
2420 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2421 	se_cmd->check_release = 1;
2422 
2423 out:
2424 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2425 	return ret;
2426 }
2427 
2428 static void target_release_cmd_kref(struct kref *kref)
2429 {
2430 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2431 	struct se_session *se_sess = se_cmd->se_sess;
2432 	unsigned long flags;
2433 
2434 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2435 	if (list_empty(&se_cmd->se_cmd_list)) {
2436 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2437 		se_cmd->se_tfo->release_cmd(se_cmd);
2438 		return;
2439 	}
2440 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2441 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2442 		complete(&se_cmd->cmd_wait_comp);
2443 		return;
2444 	}
2445 	list_del(&se_cmd->se_cmd_list);
2446 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2447 
2448 	se_cmd->se_tfo->release_cmd(se_cmd);
2449 }
2450 
2451 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2452  * @se_sess:	session to reference
2453  * @se_cmd:	command descriptor to drop
2454  */
2455 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2456 {
2457 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2458 }
2459 EXPORT_SYMBOL(target_put_sess_cmd);
2460 
2461 /* target_sess_cmd_list_set_waiting - Flag all commands in
2462  *         sess_cmd_list to complete cmd_wait_comp.  Set
2463  *         sess_tearing_down so no more commands are queued.
2464  * @se_sess:	session to flag
2465  */
2466 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2467 {
2468 	struct se_cmd *se_cmd;
2469 	unsigned long flags;
2470 
2471 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2472 
2473 	WARN_ON(se_sess->sess_tearing_down);
2474 	se_sess->sess_tearing_down = 1;
2475 
2476 	list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list)
2477 		se_cmd->cmd_wait_set = 1;
2478 
2479 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2480 }
2481 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2482 
2483 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2484  * @se_sess:    session to wait for active I/O
2485  * @wait_for_tasks:	Make extra transport_wait_for_tasks call
2486  */
2487 void target_wait_for_sess_cmds(
2488 	struct se_session *se_sess,
2489 	int wait_for_tasks)
2490 {
2491 	struct se_cmd *se_cmd, *tmp_cmd;
2492 	bool rc = false;
2493 
2494 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2495 				&se_sess->sess_cmd_list, se_cmd_list) {
2496 		list_del(&se_cmd->se_cmd_list);
2497 
2498 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2499 			" %d\n", se_cmd, se_cmd->t_state,
2500 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2501 
2502 		if (wait_for_tasks) {
2503 			pr_debug("Calling transport_wait_for_tasks se_cmd: %p t_state: %d,"
2504 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2505 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2506 
2507 			rc = transport_wait_for_tasks(se_cmd);
2508 
2509 			pr_debug("After transport_wait_for_tasks se_cmd: %p t_state: %d,"
2510 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2511 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2512 		}
2513 
2514 		if (!rc) {
2515 			wait_for_completion(&se_cmd->cmd_wait_comp);
2516 			pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2517 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2518 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2519 		}
2520 
2521 		se_cmd->se_tfo->release_cmd(se_cmd);
2522 	}
2523 }
2524 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2525 
2526 /*	transport_lun_wait_for_tasks():
2527  *
2528  *	Called from ConfigFS context to stop the passed struct se_cmd to allow
2529  *	an struct se_lun to be successfully shutdown.
2530  */
2531 static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
2532 {
2533 	unsigned long flags;
2534 	int ret = 0;
2535 
2536 	/*
2537 	 * If the frontend has already requested this struct se_cmd to
2538 	 * be stopped, we can safely ignore this struct se_cmd.
2539 	 */
2540 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2541 	if (cmd->transport_state & CMD_T_STOP) {
2542 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2543 
2544 		pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
2545 			 cmd->se_tfo->get_task_tag(cmd));
2546 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2547 		transport_cmd_check_stop(cmd, false);
2548 		return -EPERM;
2549 	}
2550 	cmd->transport_state |= CMD_T_LUN_FE_STOP;
2551 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2552 
2553 	// XXX: audit task_flags checks.
2554 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2555 	if ((cmd->transport_state & CMD_T_BUSY) &&
2556 	    (cmd->transport_state & CMD_T_SENT)) {
2557 		if (!target_stop_cmd(cmd, &flags))
2558 			ret++;
2559 	}
2560 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2561 
2562 	pr_debug("ConfigFS: cmd: %p stop tasks ret:"
2563 			" %d\n", cmd, ret);
2564 	if (!ret) {
2565 		pr_debug("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
2566 				cmd->se_tfo->get_task_tag(cmd));
2567 		wait_for_completion(&cmd->transport_lun_stop_comp);
2568 		pr_debug("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
2569 				cmd->se_tfo->get_task_tag(cmd));
2570 	}
2571 
2572 	return 0;
2573 }
2574 
2575 static void __transport_clear_lun_from_sessions(struct se_lun *lun)
2576 {
2577 	struct se_cmd *cmd = NULL;
2578 	unsigned long lun_flags, cmd_flags;
2579 	/*
2580 	 * Do exception processing and return CHECK_CONDITION status to the
2581 	 * Initiator Port.
2582 	 */
2583 	spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2584 	while (!list_empty(&lun->lun_cmd_list)) {
2585 		cmd = list_first_entry(&lun->lun_cmd_list,
2586 		       struct se_cmd, se_lun_node);
2587 		list_del_init(&cmd->se_lun_node);
2588 
2589 		spin_lock(&cmd->t_state_lock);
2590 		pr_debug("SE_LUN[%d] - Setting cmd->transport"
2591 			"_lun_stop for  ITT: 0x%08x\n",
2592 			cmd->se_lun->unpacked_lun,
2593 			cmd->se_tfo->get_task_tag(cmd));
2594 		cmd->transport_state |= CMD_T_LUN_STOP;
2595 		spin_unlock(&cmd->t_state_lock);
2596 
2597 		spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2598 
2599 		if (!cmd->se_lun) {
2600 			pr_err("ITT: 0x%08x, [i,t]_state: %u/%u\n",
2601 				cmd->se_tfo->get_task_tag(cmd),
2602 				cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2603 			BUG();
2604 		}
2605 		/*
2606 		 * If the Storage engine still owns the iscsi_cmd_t, determine
2607 		 * and/or stop its context.
2608 		 */
2609 		pr_debug("SE_LUN[%d] - ITT: 0x%08x before transport"
2610 			"_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
2611 			cmd->se_tfo->get_task_tag(cmd));
2612 
2613 		if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
2614 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2615 			continue;
2616 		}
2617 
2618 		pr_debug("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
2619 			"_wait_for_tasks(): SUCCESS\n",
2620 			cmd->se_lun->unpacked_lun,
2621 			cmd->se_tfo->get_task_tag(cmd));
2622 
2623 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2624 		if (!(cmd->transport_state & CMD_T_DEV_ACTIVE)) {
2625 			spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2626 			goto check_cond;
2627 		}
2628 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2629 		target_remove_from_state_list(cmd);
2630 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2631 
2632 		/*
2633 		 * The Storage engine stopped this struct se_cmd before it was
2634 		 * send to the fabric frontend for delivery back to the
2635 		 * Initiator Node.  Return this SCSI CDB back with an
2636 		 * CHECK_CONDITION status.
2637 		 */
2638 check_cond:
2639 		transport_send_check_condition_and_sense(cmd,
2640 				TCM_NON_EXISTENT_LUN, 0);
2641 		/*
2642 		 *  If the fabric frontend is waiting for this iscsi_cmd_t to
2643 		 * be released, notify the waiting thread now that LU has
2644 		 * finished accessing it.
2645 		 */
2646 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2647 		if (cmd->transport_state & CMD_T_LUN_FE_STOP) {
2648 			pr_debug("SE_LUN[%d] - Detected FE stop for"
2649 				" struct se_cmd: %p ITT: 0x%08x\n",
2650 				lun->unpacked_lun,
2651 				cmd, cmd->se_tfo->get_task_tag(cmd));
2652 
2653 			spin_unlock_irqrestore(&cmd->t_state_lock,
2654 					cmd_flags);
2655 			transport_cmd_check_stop(cmd, false);
2656 			complete(&cmd->transport_lun_fe_stop_comp);
2657 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2658 			continue;
2659 		}
2660 		pr_debug("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
2661 			lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));
2662 
2663 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2664 		spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2665 	}
2666 	spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2667 }
2668 
2669 static int transport_clear_lun_thread(void *p)
2670 {
2671 	struct se_lun *lun = p;
2672 
2673 	__transport_clear_lun_from_sessions(lun);
2674 	complete(&lun->lun_shutdown_comp);
2675 
2676 	return 0;
2677 }
2678 
2679 int transport_clear_lun_from_sessions(struct se_lun *lun)
2680 {
2681 	struct task_struct *kt;
2682 
2683 	kt = kthread_run(transport_clear_lun_thread, lun,
2684 			"tcm_cl_%u", lun->unpacked_lun);
2685 	if (IS_ERR(kt)) {
2686 		pr_err("Unable to start clear_lun thread\n");
2687 		return PTR_ERR(kt);
2688 	}
2689 	wait_for_completion(&lun->lun_shutdown_comp);
2690 
2691 	return 0;
2692 }
2693 
2694 /**
2695  * transport_wait_for_tasks - wait for completion to occur
2696  * @cmd:	command to wait
2697  *
2698  * Called from frontend fabric context to wait for storage engine
2699  * to pause and/or release frontend generated struct se_cmd.
2700  */
2701 bool transport_wait_for_tasks(struct se_cmd *cmd)
2702 {
2703 	unsigned long flags;
2704 
2705 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2706 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2707 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2708 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2709 		return false;
2710 	}
2711 
2712 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2713 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2714 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2715 		return false;
2716 	}
2717 	/*
2718 	 * If we are already stopped due to an external event (ie: LUN shutdown)
2719 	 * sleep until the connection can have the passed struct se_cmd back.
2720 	 * The cmd->transport_lun_stopped_sem will be upped by
2721 	 * transport_clear_lun_from_sessions() once the ConfigFS context caller
2722 	 * has completed its operation on the struct se_cmd.
2723 	 */
2724 	if (cmd->transport_state & CMD_T_LUN_STOP) {
2725 		pr_debug("wait_for_tasks: Stopping"
2726 			" wait_for_completion(&cmd->t_tasktransport_lun_fe"
2727 			"_stop_comp); for ITT: 0x%08x\n",
2728 			cmd->se_tfo->get_task_tag(cmd));
2729 		/*
2730 		 * There is a special case for WRITES where a FE exception +
2731 		 * LUN shutdown means ConfigFS context is still sleeping on
2732 		 * transport_lun_stop_comp in transport_lun_wait_for_tasks().
2733 		 * We go ahead and up transport_lun_stop_comp just to be sure
2734 		 * here.
2735 		 */
2736 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2737 		complete(&cmd->transport_lun_stop_comp);
2738 		wait_for_completion(&cmd->transport_lun_fe_stop_comp);
2739 		spin_lock_irqsave(&cmd->t_state_lock, flags);
2740 
2741 		target_remove_from_state_list(cmd);
2742 		/*
2743 		 * At this point, the frontend who was the originator of this
2744 		 * struct se_cmd, now owns the structure and can be released through
2745 		 * normal means below.
2746 		 */
2747 		pr_debug("wait_for_tasks: Stopped"
2748 			" wait_for_completion(&cmd->t_tasktransport_lun_fe_"
2749 			"stop_comp); for ITT: 0x%08x\n",
2750 			cmd->se_tfo->get_task_tag(cmd));
2751 
2752 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2753 	}
2754 
2755 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2756 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2757 		return false;
2758 	}
2759 
2760 	cmd->transport_state |= CMD_T_STOP;
2761 
2762 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2763 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2764 		cmd, cmd->se_tfo->get_task_tag(cmd),
2765 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2766 
2767 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2768 
2769 	wait_for_completion(&cmd->t_transport_stop_comp);
2770 
2771 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2772 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2773 
2774 	pr_debug("wait_for_tasks: Stopped wait_for_compltion("
2775 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2776 		cmd->se_tfo->get_task_tag(cmd));
2777 
2778 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2779 
2780 	return true;
2781 }
2782 EXPORT_SYMBOL(transport_wait_for_tasks);
2783 
2784 static int transport_get_sense_codes(
2785 	struct se_cmd *cmd,
2786 	u8 *asc,
2787 	u8 *ascq)
2788 {
2789 	*asc = cmd->scsi_asc;
2790 	*ascq = cmd->scsi_ascq;
2791 
2792 	return 0;
2793 }
2794 
2795 static int transport_set_sense_codes(
2796 	struct se_cmd *cmd,
2797 	u8 asc,
2798 	u8 ascq)
2799 {
2800 	cmd->scsi_asc = asc;
2801 	cmd->scsi_ascq = ascq;
2802 
2803 	return 0;
2804 }
2805 
2806 int transport_send_check_condition_and_sense(
2807 	struct se_cmd *cmd,
2808 	u8 reason,
2809 	int from_transport)
2810 {
2811 	unsigned char *buffer = cmd->sense_buffer;
2812 	unsigned long flags;
2813 	int offset;
2814 	u8 asc = 0, ascq = 0;
2815 
2816 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2817 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2818 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2819 		return 0;
2820 	}
2821 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2822 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2823 
2824 	if (!reason && from_transport)
2825 		goto after_reason;
2826 
2827 	if (!from_transport)
2828 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2829 	/*
2830 	 * Data Segment and SenseLength of the fabric response PDU.
2831 	 *
2832 	 * TRANSPORT_SENSE_BUFFER is now set to SCSI_SENSE_BUFFERSIZE
2833 	 * from include/scsi/scsi_cmnd.h
2834 	 */
2835 	offset = cmd->se_tfo->set_fabric_sense_len(cmd,
2836 				TRANSPORT_SENSE_BUFFER);
2837 	/*
2838 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2839 	 * SENSE KEY values from include/scsi/scsi.h
2840 	 */
2841 	switch (reason) {
2842 	case TCM_NON_EXISTENT_LUN:
2843 		/* CURRENT ERROR */
2844 		buffer[offset] = 0x70;
2845 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2846 		/* ILLEGAL REQUEST */
2847 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2848 		/* LOGICAL UNIT NOT SUPPORTED */
2849 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x25;
2850 		break;
2851 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2852 	case TCM_SECTOR_COUNT_TOO_MANY:
2853 		/* CURRENT ERROR */
2854 		buffer[offset] = 0x70;
2855 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2856 		/* ILLEGAL REQUEST */
2857 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2858 		/* INVALID COMMAND OPERATION CODE */
2859 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x20;
2860 		break;
2861 	case TCM_UNKNOWN_MODE_PAGE:
2862 		/* CURRENT ERROR */
2863 		buffer[offset] = 0x70;
2864 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2865 		/* ILLEGAL REQUEST */
2866 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2867 		/* INVALID FIELD IN CDB */
2868 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x24;
2869 		break;
2870 	case TCM_CHECK_CONDITION_ABORT_CMD:
2871 		/* CURRENT ERROR */
2872 		buffer[offset] = 0x70;
2873 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2874 		/* ABORTED COMMAND */
2875 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2876 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2877 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x29;
2878 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x03;
2879 		break;
2880 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2881 		/* CURRENT ERROR */
2882 		buffer[offset] = 0x70;
2883 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2884 		/* ABORTED COMMAND */
2885 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2886 		/* WRITE ERROR */
2887 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x0c;
2888 		/* NOT ENOUGH UNSOLICITED DATA */
2889 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x0d;
2890 		break;
2891 	case TCM_INVALID_CDB_FIELD:
2892 		/* CURRENT ERROR */
2893 		buffer[offset] = 0x70;
2894 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2895 		/* ILLEGAL REQUEST */
2896 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2897 		/* INVALID FIELD IN CDB */
2898 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x24;
2899 		break;
2900 	case TCM_INVALID_PARAMETER_LIST:
2901 		/* CURRENT ERROR */
2902 		buffer[offset] = 0x70;
2903 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2904 		/* ILLEGAL REQUEST */
2905 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2906 		/* INVALID FIELD IN PARAMETER LIST */
2907 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x26;
2908 		break;
2909 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2910 		/* CURRENT ERROR */
2911 		buffer[offset] = 0x70;
2912 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2913 		/* ABORTED COMMAND */
2914 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2915 		/* WRITE ERROR */
2916 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x0c;
2917 		/* UNEXPECTED_UNSOLICITED_DATA */
2918 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x0c;
2919 		break;
2920 	case TCM_SERVICE_CRC_ERROR:
2921 		/* CURRENT ERROR */
2922 		buffer[offset] = 0x70;
2923 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2924 		/* ABORTED COMMAND */
2925 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2926 		/* PROTOCOL SERVICE CRC ERROR */
2927 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x47;
2928 		/* N/A */
2929 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x05;
2930 		break;
2931 	case TCM_SNACK_REJECTED:
2932 		/* CURRENT ERROR */
2933 		buffer[offset] = 0x70;
2934 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2935 		/* ABORTED COMMAND */
2936 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2937 		/* READ ERROR */
2938 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x11;
2939 		/* FAILED RETRANSMISSION REQUEST */
2940 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x13;
2941 		break;
2942 	case TCM_WRITE_PROTECTED:
2943 		/* CURRENT ERROR */
2944 		buffer[offset] = 0x70;
2945 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2946 		/* DATA PROTECT */
2947 		buffer[offset+SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2948 		/* WRITE PROTECTED */
2949 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x27;
2950 		break;
2951 	case TCM_ADDRESS_OUT_OF_RANGE:
2952 		/* CURRENT ERROR */
2953 		buffer[offset] = 0x70;
2954 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2955 		/* ILLEGAL REQUEST */
2956 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2957 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2958 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x21;
2959 		break;
2960 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2961 		/* CURRENT ERROR */
2962 		buffer[offset] = 0x70;
2963 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2964 		/* UNIT ATTENTION */
2965 		buffer[offset+SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2966 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2967 		buffer[offset+SPC_ASC_KEY_OFFSET] = asc;
2968 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = ascq;
2969 		break;
2970 	case TCM_CHECK_CONDITION_NOT_READY:
2971 		/* CURRENT ERROR */
2972 		buffer[offset] = 0x70;
2973 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2974 		/* Not Ready */
2975 		buffer[offset+SPC_SENSE_KEY_OFFSET] = NOT_READY;
2976 		transport_get_sense_codes(cmd, &asc, &ascq);
2977 		buffer[offset+SPC_ASC_KEY_OFFSET] = asc;
2978 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = ascq;
2979 		break;
2980 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2981 	default:
2982 		/* CURRENT ERROR */
2983 		buffer[offset] = 0x70;
2984 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2985 		/* ILLEGAL REQUEST */
2986 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2987 		/* LOGICAL UNIT COMMUNICATION FAILURE */
2988 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x80;
2989 		break;
2990 	}
2991 	/*
2992 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
2993 	 */
2994 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2995 	/*
2996 	 * Automatically padded, this value is encoded in the fabric's
2997 	 * data_length response PDU containing the SCSI defined sense data.
2998 	 */
2999 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER + offset;
3000 
3001 after_reason:
3002 	return cmd->se_tfo->queue_status(cmd);
3003 }
3004 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3005 
3006 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3007 {
3008 	int ret = 0;
3009 
3010 	if (cmd->transport_state & CMD_T_ABORTED) {
3011 		if (!send_status ||
3012 		     (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
3013 			return 1;
3014 
3015 		pr_debug("Sending delayed SAM_STAT_TASK_ABORTED"
3016 			" status for CDB: 0x%02x ITT: 0x%08x\n",
3017 			cmd->t_task_cdb[0],
3018 			cmd->se_tfo->get_task_tag(cmd));
3019 
3020 		cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
3021 		cmd->se_tfo->queue_status(cmd);
3022 		ret = 1;
3023 	}
3024 	return ret;
3025 }
3026 EXPORT_SYMBOL(transport_check_aborted_status);
3027 
3028 void transport_send_task_abort(struct se_cmd *cmd)
3029 {
3030 	unsigned long flags;
3031 
3032 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3033 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3034 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3035 		return;
3036 	}
3037 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3038 
3039 	/*
3040 	 * If there are still expected incoming fabric WRITEs, we wait
3041 	 * until until they have completed before sending a TASK_ABORTED
3042 	 * response.  This response with TASK_ABORTED status will be
3043 	 * queued back to fabric module by transport_check_aborted_status().
3044 	 */
3045 	if (cmd->data_direction == DMA_TO_DEVICE) {
3046 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3047 			cmd->transport_state |= CMD_T_ABORTED;
3048 			smp_mb__after_atomic_inc();
3049 		}
3050 	}
3051 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3052 
3053 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
3054 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
3055 		cmd->se_tfo->get_task_tag(cmd));
3056 
3057 	cmd->se_tfo->queue_status(cmd);
3058 }
3059 
3060 static void target_tmr_work(struct work_struct *work)
3061 {
3062 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3063 	struct se_device *dev = cmd->se_dev;
3064 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3065 	int ret;
3066 
3067 	switch (tmr->function) {
3068 	case TMR_ABORT_TASK:
3069 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3070 		break;
3071 	case TMR_ABORT_TASK_SET:
3072 	case TMR_CLEAR_ACA:
3073 	case TMR_CLEAR_TASK_SET:
3074 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3075 		break;
3076 	case TMR_LUN_RESET:
3077 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3078 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3079 					 TMR_FUNCTION_REJECTED;
3080 		break;
3081 	case TMR_TARGET_WARM_RESET:
3082 		tmr->response = TMR_FUNCTION_REJECTED;
3083 		break;
3084 	case TMR_TARGET_COLD_RESET:
3085 		tmr->response = TMR_FUNCTION_REJECTED;
3086 		break;
3087 	default:
3088 		pr_err("Uknown TMR function: 0x%02x.\n",
3089 				tmr->function);
3090 		tmr->response = TMR_FUNCTION_REJECTED;
3091 		break;
3092 	}
3093 
3094 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3095 	cmd->se_tfo->queue_tm_rsp(cmd);
3096 
3097 	transport_cmd_check_stop_to_fabric(cmd);
3098 }
3099 
3100 int transport_generic_handle_tmr(
3101 	struct se_cmd *cmd)
3102 {
3103 	INIT_WORK(&cmd->work, target_tmr_work);
3104 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3105 	return 0;
3106 }
3107 EXPORT_SYMBOL(transport_generic_handle_tmr);
3108