xref: /linux/drivers/target/target_core_transport.c (revision f49f4ab95c301dbccad0efe85296d908b8ae7ad4)
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 struct workqueue_struct *target_completion_wq;
59 static struct kmem_cache *se_sess_cache;
60 struct kmem_cache *se_ua_cache;
61 struct kmem_cache *t10_pr_reg_cache;
62 struct kmem_cache *t10_alua_lu_gp_cache;
63 struct kmem_cache *t10_alua_lu_gp_mem_cache;
64 struct kmem_cache *t10_alua_tg_pt_gp_cache;
65 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
66 
67 static void transport_complete_task_attr(struct se_cmd *cmd);
68 static void transport_handle_queue_full(struct se_cmd *cmd,
69 		struct se_device *dev);
70 static int transport_generic_get_mem(struct se_cmd *cmd);
71 static int target_get_sess_cmd(struct se_session *, struct se_cmd *, bool);
72 static void transport_put_cmd(struct se_cmd *cmd);
73 static int transport_set_sense_codes(struct se_cmd *cmd, u8 asc, u8 ascq);
74 static void target_complete_ok_work(struct work_struct *work);
75 
76 int init_se_kmem_caches(void)
77 {
78 	se_sess_cache = kmem_cache_create("se_sess_cache",
79 			sizeof(struct se_session), __alignof__(struct se_session),
80 			0, NULL);
81 	if (!se_sess_cache) {
82 		pr_err("kmem_cache_create() for struct se_session"
83 				" failed\n");
84 		goto out;
85 	}
86 	se_ua_cache = kmem_cache_create("se_ua_cache",
87 			sizeof(struct se_ua), __alignof__(struct se_ua),
88 			0, NULL);
89 	if (!se_ua_cache) {
90 		pr_err("kmem_cache_create() for struct se_ua failed\n");
91 		goto out_free_sess_cache;
92 	}
93 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
94 			sizeof(struct t10_pr_registration),
95 			__alignof__(struct t10_pr_registration), 0, NULL);
96 	if (!t10_pr_reg_cache) {
97 		pr_err("kmem_cache_create() for struct t10_pr_registration"
98 				" failed\n");
99 		goto out_free_ua_cache;
100 	}
101 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
102 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
103 			0, NULL);
104 	if (!t10_alua_lu_gp_cache) {
105 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
106 				" failed\n");
107 		goto out_free_pr_reg_cache;
108 	}
109 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
110 			sizeof(struct t10_alua_lu_gp_member),
111 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
112 	if (!t10_alua_lu_gp_mem_cache) {
113 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
114 				"cache failed\n");
115 		goto out_free_lu_gp_cache;
116 	}
117 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
118 			sizeof(struct t10_alua_tg_pt_gp),
119 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
120 	if (!t10_alua_tg_pt_gp_cache) {
121 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
122 				"cache failed\n");
123 		goto out_free_lu_gp_mem_cache;
124 	}
125 	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
126 			"t10_alua_tg_pt_gp_mem_cache",
127 			sizeof(struct t10_alua_tg_pt_gp_member),
128 			__alignof__(struct t10_alua_tg_pt_gp_member),
129 			0, NULL);
130 	if (!t10_alua_tg_pt_gp_mem_cache) {
131 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
132 				"mem_t failed\n");
133 		goto out_free_tg_pt_gp_cache;
134 	}
135 
136 	target_completion_wq = alloc_workqueue("target_completion",
137 					       WQ_MEM_RECLAIM, 0);
138 	if (!target_completion_wq)
139 		goto out_free_tg_pt_gp_mem_cache;
140 
141 	return 0;
142 
143 out_free_tg_pt_gp_mem_cache:
144 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
145 out_free_tg_pt_gp_cache:
146 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
147 out_free_lu_gp_mem_cache:
148 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
149 out_free_lu_gp_cache:
150 	kmem_cache_destroy(t10_alua_lu_gp_cache);
151 out_free_pr_reg_cache:
152 	kmem_cache_destroy(t10_pr_reg_cache);
153 out_free_ua_cache:
154 	kmem_cache_destroy(se_ua_cache);
155 out_free_sess_cache:
156 	kmem_cache_destroy(se_sess_cache);
157 out:
158 	return -ENOMEM;
159 }
160 
161 void release_se_kmem_caches(void)
162 {
163 	destroy_workqueue(target_completion_wq);
164 	kmem_cache_destroy(se_sess_cache);
165 	kmem_cache_destroy(se_ua_cache);
166 	kmem_cache_destroy(t10_pr_reg_cache);
167 	kmem_cache_destroy(t10_alua_lu_gp_cache);
168 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
169 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
170 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
171 }
172 
173 /* This code ensures unique mib indexes are handed out. */
174 static DEFINE_SPINLOCK(scsi_mib_index_lock);
175 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
176 
177 /*
178  * Allocate a new row index for the entry type specified
179  */
180 u32 scsi_get_new_index(scsi_index_t type)
181 {
182 	u32 new_index;
183 
184 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
185 
186 	spin_lock(&scsi_mib_index_lock);
187 	new_index = ++scsi_mib_index[type];
188 	spin_unlock(&scsi_mib_index_lock);
189 
190 	return new_index;
191 }
192 
193 void transport_subsystem_check_init(void)
194 {
195 	int ret;
196 	static int sub_api_initialized;
197 
198 	if (sub_api_initialized)
199 		return;
200 
201 	ret = request_module("target_core_iblock");
202 	if (ret != 0)
203 		pr_err("Unable to load target_core_iblock\n");
204 
205 	ret = request_module("target_core_file");
206 	if (ret != 0)
207 		pr_err("Unable to load target_core_file\n");
208 
209 	ret = request_module("target_core_pscsi");
210 	if (ret != 0)
211 		pr_err("Unable to load target_core_pscsi\n");
212 
213 	sub_api_initialized = 1;
214 }
215 
216 struct se_session *transport_init_session(void)
217 {
218 	struct se_session *se_sess;
219 
220 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
221 	if (!se_sess) {
222 		pr_err("Unable to allocate struct se_session from"
223 				" se_sess_cache\n");
224 		return ERR_PTR(-ENOMEM);
225 	}
226 	INIT_LIST_HEAD(&se_sess->sess_list);
227 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
228 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
229 	spin_lock_init(&se_sess->sess_cmd_lock);
230 	kref_init(&se_sess->sess_kref);
231 
232 	return se_sess;
233 }
234 EXPORT_SYMBOL(transport_init_session);
235 
236 /*
237  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
238  */
239 void __transport_register_session(
240 	struct se_portal_group *se_tpg,
241 	struct se_node_acl *se_nacl,
242 	struct se_session *se_sess,
243 	void *fabric_sess_ptr)
244 {
245 	unsigned char buf[PR_REG_ISID_LEN];
246 
247 	se_sess->se_tpg = se_tpg;
248 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
249 	/*
250 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
251 	 *
252 	 * Only set for struct se_session's that will actually be moving I/O.
253 	 * eg: *NOT* discovery sessions.
254 	 */
255 	if (se_nacl) {
256 		/*
257 		 * If the fabric module supports an ISID based TransportID,
258 		 * save this value in binary from the fabric I_T Nexus now.
259 		 */
260 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
261 			memset(&buf[0], 0, PR_REG_ISID_LEN);
262 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
263 					&buf[0], PR_REG_ISID_LEN);
264 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
265 		}
266 		kref_get(&se_nacl->acl_kref);
267 
268 		spin_lock_irq(&se_nacl->nacl_sess_lock);
269 		/*
270 		 * The se_nacl->nacl_sess pointer will be set to the
271 		 * last active I_T Nexus for each struct se_node_acl.
272 		 */
273 		se_nacl->nacl_sess = se_sess;
274 
275 		list_add_tail(&se_sess->sess_acl_list,
276 			      &se_nacl->acl_sess_list);
277 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
278 	}
279 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
280 
281 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
282 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
283 }
284 EXPORT_SYMBOL(__transport_register_session);
285 
286 void transport_register_session(
287 	struct se_portal_group *se_tpg,
288 	struct se_node_acl *se_nacl,
289 	struct se_session *se_sess,
290 	void *fabric_sess_ptr)
291 {
292 	unsigned long flags;
293 
294 	spin_lock_irqsave(&se_tpg->session_lock, flags);
295 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
296 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
297 }
298 EXPORT_SYMBOL(transport_register_session);
299 
300 void target_release_session(struct kref *kref)
301 {
302 	struct se_session *se_sess = container_of(kref,
303 			struct se_session, sess_kref);
304 	struct se_portal_group *se_tpg = se_sess->se_tpg;
305 
306 	se_tpg->se_tpg_tfo->close_session(se_sess);
307 }
308 
309 void target_get_session(struct se_session *se_sess)
310 {
311 	kref_get(&se_sess->sess_kref);
312 }
313 EXPORT_SYMBOL(target_get_session);
314 
315 void target_put_session(struct se_session *se_sess)
316 {
317 	struct se_portal_group *tpg = se_sess->se_tpg;
318 
319 	if (tpg->se_tpg_tfo->put_session != NULL) {
320 		tpg->se_tpg_tfo->put_session(se_sess);
321 		return;
322 	}
323 	kref_put(&se_sess->sess_kref, target_release_session);
324 }
325 EXPORT_SYMBOL(target_put_session);
326 
327 static void target_complete_nacl(struct kref *kref)
328 {
329 	struct se_node_acl *nacl = container_of(kref,
330 				struct se_node_acl, acl_kref);
331 
332 	complete(&nacl->acl_free_comp);
333 }
334 
335 void target_put_nacl(struct se_node_acl *nacl)
336 {
337 	kref_put(&nacl->acl_kref, target_complete_nacl);
338 }
339 
340 void transport_deregister_session_configfs(struct se_session *se_sess)
341 {
342 	struct se_node_acl *se_nacl;
343 	unsigned long flags;
344 	/*
345 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
346 	 */
347 	se_nacl = se_sess->se_node_acl;
348 	if (se_nacl) {
349 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
350 		if (se_nacl->acl_stop == 0)
351 			list_del(&se_sess->sess_acl_list);
352 		/*
353 		 * If the session list is empty, then clear the pointer.
354 		 * Otherwise, set the struct se_session pointer from the tail
355 		 * element of the per struct se_node_acl active session list.
356 		 */
357 		if (list_empty(&se_nacl->acl_sess_list))
358 			se_nacl->nacl_sess = NULL;
359 		else {
360 			se_nacl->nacl_sess = container_of(
361 					se_nacl->acl_sess_list.prev,
362 					struct se_session, sess_acl_list);
363 		}
364 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
365 	}
366 }
367 EXPORT_SYMBOL(transport_deregister_session_configfs);
368 
369 void transport_free_session(struct se_session *se_sess)
370 {
371 	kmem_cache_free(se_sess_cache, se_sess);
372 }
373 EXPORT_SYMBOL(transport_free_session);
374 
375 void transport_deregister_session(struct se_session *se_sess)
376 {
377 	struct se_portal_group *se_tpg = se_sess->se_tpg;
378 	struct target_core_fabric_ops *se_tfo;
379 	struct se_node_acl *se_nacl;
380 	unsigned long flags;
381 	bool comp_nacl = true;
382 
383 	if (!se_tpg) {
384 		transport_free_session(se_sess);
385 		return;
386 	}
387 	se_tfo = se_tpg->se_tpg_tfo;
388 
389 	spin_lock_irqsave(&se_tpg->session_lock, flags);
390 	list_del(&se_sess->sess_list);
391 	se_sess->se_tpg = NULL;
392 	se_sess->fabric_sess_ptr = NULL;
393 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
394 
395 	/*
396 	 * Determine if we need to do extra work for this initiator node's
397 	 * struct se_node_acl if it had been previously dynamically generated.
398 	 */
399 	se_nacl = se_sess->se_node_acl;
400 
401 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
402 	if (se_nacl && se_nacl->dynamic_node_acl) {
403 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
404 			list_del(&se_nacl->acl_list);
405 			se_tpg->num_node_acls--;
406 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
407 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
408 			core_free_device_list_for_node(se_nacl, se_tpg);
409 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
410 
411 			comp_nacl = false;
412 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
413 		}
414 	}
415 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
416 
417 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
418 		se_tpg->se_tpg_tfo->get_fabric_name());
419 	/*
420 	 * If last kref is dropping now for an explict NodeACL, awake sleeping
421 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
422 	 * removal context.
423 	 */
424 	if (se_nacl && comp_nacl == true)
425 		target_put_nacl(se_nacl);
426 
427 	transport_free_session(se_sess);
428 }
429 EXPORT_SYMBOL(transport_deregister_session);
430 
431 /*
432  * Called with cmd->t_state_lock held.
433  */
434 static void target_remove_from_state_list(struct se_cmd *cmd)
435 {
436 	struct se_device *dev = cmd->se_dev;
437 	unsigned long flags;
438 
439 	if (!dev)
440 		return;
441 
442 	if (cmd->transport_state & CMD_T_BUSY)
443 		return;
444 
445 	spin_lock_irqsave(&dev->execute_task_lock, flags);
446 	if (cmd->state_active) {
447 		list_del(&cmd->state_list);
448 		cmd->state_active = false;
449 	}
450 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
451 }
452 
453 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists)
454 {
455 	unsigned long flags;
456 
457 	spin_lock_irqsave(&cmd->t_state_lock, flags);
458 	/*
459 	 * Determine if IOCTL context caller in requesting the stopping of this
460 	 * command for LUN shutdown purposes.
461 	 */
462 	if (cmd->transport_state & CMD_T_LUN_STOP) {
463 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
464 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
465 
466 		cmd->transport_state &= ~CMD_T_ACTIVE;
467 		if (remove_from_lists)
468 			target_remove_from_state_list(cmd);
469 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
470 
471 		complete(&cmd->transport_lun_stop_comp);
472 		return 1;
473 	}
474 
475 	if (remove_from_lists) {
476 		target_remove_from_state_list(cmd);
477 
478 		/*
479 		 * Clear struct se_cmd->se_lun before the handoff to FE.
480 		 */
481 		cmd->se_lun = NULL;
482 	}
483 
484 	/*
485 	 * Determine if frontend context caller is requesting the stopping of
486 	 * this command for frontend exceptions.
487 	 */
488 	if (cmd->transport_state & CMD_T_STOP) {
489 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
490 			__func__, __LINE__,
491 			cmd->se_tfo->get_task_tag(cmd));
492 
493 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
494 
495 		complete(&cmd->t_transport_stop_comp);
496 		return 1;
497 	}
498 
499 	cmd->transport_state &= ~CMD_T_ACTIVE;
500 	if (remove_from_lists) {
501 		/*
502 		 * Some fabric modules like tcm_loop can release
503 		 * their internally allocated I/O reference now and
504 		 * struct se_cmd now.
505 		 *
506 		 * Fabric modules are expected to return '1' here if the
507 		 * se_cmd being passed is released at this point,
508 		 * or zero if not being released.
509 		 */
510 		if (cmd->se_tfo->check_stop_free != NULL) {
511 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
512 			return cmd->se_tfo->check_stop_free(cmd);
513 		}
514 	}
515 
516 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
517 	return 0;
518 }
519 
520 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
521 {
522 	return transport_cmd_check_stop(cmd, true);
523 }
524 
525 static void transport_lun_remove_cmd(struct se_cmd *cmd)
526 {
527 	struct se_lun *lun = cmd->se_lun;
528 	unsigned long flags;
529 
530 	if (!lun)
531 		return;
532 
533 	spin_lock_irqsave(&cmd->t_state_lock, flags);
534 	if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
535 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
536 		target_remove_from_state_list(cmd);
537 	}
538 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
539 
540 	spin_lock_irqsave(&lun->lun_cmd_lock, flags);
541 	if (!list_empty(&cmd->se_lun_node))
542 		list_del_init(&cmd->se_lun_node);
543 	spin_unlock_irqrestore(&lun->lun_cmd_lock, flags);
544 }
545 
546 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
547 {
548 	if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
549 		transport_lun_remove_cmd(cmd);
550 
551 	if (transport_cmd_check_stop_to_fabric(cmd))
552 		return;
553 	if (remove)
554 		transport_put_cmd(cmd);
555 }
556 
557 static void target_complete_failure_work(struct work_struct *work)
558 {
559 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
560 
561 	transport_generic_request_failure(cmd);
562 }
563 
564 /*
565  * Used when asking transport to copy Sense Data from the underlying
566  * Linux/SCSI struct scsi_cmnd
567  */
568 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
569 {
570 	struct se_device *dev = cmd->se_dev;
571 
572 	WARN_ON(!cmd->se_lun);
573 
574 	if (!dev)
575 		return NULL;
576 
577 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
578 		return NULL;
579 
580 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
581 
582 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
583 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
584 	return cmd->sense_buffer;
585 }
586 
587 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
588 {
589 	struct se_device *dev = cmd->se_dev;
590 	int success = scsi_status == GOOD;
591 	unsigned long flags;
592 
593 	cmd->scsi_status = scsi_status;
594 
595 
596 	spin_lock_irqsave(&cmd->t_state_lock, flags);
597 	cmd->transport_state &= ~CMD_T_BUSY;
598 
599 	if (dev && dev->transport->transport_complete) {
600 		dev->transport->transport_complete(cmd,
601 				cmd->t_data_sg,
602 				transport_get_sense_buffer(cmd));
603 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
604 			success = 1;
605 	}
606 
607 	/*
608 	 * See if we are waiting to complete for an exception condition.
609 	 */
610 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
611 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
612 		complete(&cmd->task_stop_comp);
613 		return;
614 	}
615 
616 	if (!success)
617 		cmd->transport_state |= CMD_T_FAILED;
618 
619 	/*
620 	 * Check for case where an explict ABORT_TASK has been received
621 	 * and transport_wait_for_tasks() will be waiting for completion..
622 	 */
623 	if (cmd->transport_state & CMD_T_ABORTED &&
624 	    cmd->transport_state & CMD_T_STOP) {
625 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
626 		complete(&cmd->t_transport_stop_comp);
627 		return;
628 	} else if (cmd->transport_state & CMD_T_FAILED) {
629 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
630 		INIT_WORK(&cmd->work, target_complete_failure_work);
631 	} else {
632 		INIT_WORK(&cmd->work, target_complete_ok_work);
633 	}
634 
635 	cmd->t_state = TRANSPORT_COMPLETE;
636 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
637 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
638 
639 	queue_work(target_completion_wq, &cmd->work);
640 }
641 EXPORT_SYMBOL(target_complete_cmd);
642 
643 static void target_add_to_state_list(struct se_cmd *cmd)
644 {
645 	struct se_device *dev = cmd->se_dev;
646 	unsigned long flags;
647 
648 	spin_lock_irqsave(&dev->execute_task_lock, flags);
649 	if (!cmd->state_active) {
650 		list_add_tail(&cmd->state_list, &dev->state_list);
651 		cmd->state_active = true;
652 	}
653 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
654 }
655 
656 /*
657  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
658  */
659 static void transport_write_pending_qf(struct se_cmd *cmd);
660 static void transport_complete_qf(struct se_cmd *cmd);
661 
662 static void target_qf_do_work(struct work_struct *work)
663 {
664 	struct se_device *dev = container_of(work, struct se_device,
665 					qf_work_queue);
666 	LIST_HEAD(qf_cmd_list);
667 	struct se_cmd *cmd, *cmd_tmp;
668 
669 	spin_lock_irq(&dev->qf_cmd_lock);
670 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
671 	spin_unlock_irq(&dev->qf_cmd_lock);
672 
673 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
674 		list_del(&cmd->se_qf_node);
675 		atomic_dec(&dev->dev_qf_count);
676 		smp_mb__after_atomic_dec();
677 
678 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
679 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
680 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
681 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
682 			: "UNKNOWN");
683 
684 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
685 			transport_write_pending_qf(cmd);
686 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
687 			transport_complete_qf(cmd);
688 	}
689 }
690 
691 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
692 {
693 	switch (cmd->data_direction) {
694 	case DMA_NONE:
695 		return "NONE";
696 	case DMA_FROM_DEVICE:
697 		return "READ";
698 	case DMA_TO_DEVICE:
699 		return "WRITE";
700 	case DMA_BIDIRECTIONAL:
701 		return "BIDI";
702 	default:
703 		break;
704 	}
705 
706 	return "UNKNOWN";
707 }
708 
709 void transport_dump_dev_state(
710 	struct se_device *dev,
711 	char *b,
712 	int *bl)
713 {
714 	*bl += sprintf(b + *bl, "Status: ");
715 	switch (dev->dev_status) {
716 	case TRANSPORT_DEVICE_ACTIVATED:
717 		*bl += sprintf(b + *bl, "ACTIVATED");
718 		break;
719 	case TRANSPORT_DEVICE_DEACTIVATED:
720 		*bl += sprintf(b + *bl, "DEACTIVATED");
721 		break;
722 	case TRANSPORT_DEVICE_SHUTDOWN:
723 		*bl += sprintf(b + *bl, "SHUTDOWN");
724 		break;
725 	case TRANSPORT_DEVICE_OFFLINE_ACTIVATED:
726 	case TRANSPORT_DEVICE_OFFLINE_DEACTIVATED:
727 		*bl += sprintf(b + *bl, "OFFLINE");
728 		break;
729 	default:
730 		*bl += sprintf(b + *bl, "UNKNOWN=%d", dev->dev_status);
731 		break;
732 	}
733 
734 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
735 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
736 		dev->se_sub_dev->se_dev_attrib.block_size,
737 		dev->se_sub_dev->se_dev_attrib.hw_max_sectors);
738 	*bl += sprintf(b + *bl, "        ");
739 }
740 
741 void transport_dump_vpd_proto_id(
742 	struct t10_vpd *vpd,
743 	unsigned char *p_buf,
744 	int p_buf_len)
745 {
746 	unsigned char buf[VPD_TMP_BUF_SIZE];
747 	int len;
748 
749 	memset(buf, 0, VPD_TMP_BUF_SIZE);
750 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
751 
752 	switch (vpd->protocol_identifier) {
753 	case 0x00:
754 		sprintf(buf+len, "Fibre Channel\n");
755 		break;
756 	case 0x10:
757 		sprintf(buf+len, "Parallel SCSI\n");
758 		break;
759 	case 0x20:
760 		sprintf(buf+len, "SSA\n");
761 		break;
762 	case 0x30:
763 		sprintf(buf+len, "IEEE 1394\n");
764 		break;
765 	case 0x40:
766 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
767 				" Protocol\n");
768 		break;
769 	case 0x50:
770 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
771 		break;
772 	case 0x60:
773 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
774 		break;
775 	case 0x70:
776 		sprintf(buf+len, "Automation/Drive Interface Transport"
777 				" Protocol\n");
778 		break;
779 	case 0x80:
780 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
781 		break;
782 	default:
783 		sprintf(buf+len, "Unknown 0x%02x\n",
784 				vpd->protocol_identifier);
785 		break;
786 	}
787 
788 	if (p_buf)
789 		strncpy(p_buf, buf, p_buf_len);
790 	else
791 		pr_debug("%s", buf);
792 }
793 
794 void
795 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
796 {
797 	/*
798 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
799 	 *
800 	 * from spc3r23.pdf section 7.5.1
801 	 */
802 	 if (page_83[1] & 0x80) {
803 		vpd->protocol_identifier = (page_83[0] & 0xf0);
804 		vpd->protocol_identifier_set = 1;
805 		transport_dump_vpd_proto_id(vpd, NULL, 0);
806 	}
807 }
808 EXPORT_SYMBOL(transport_set_vpd_proto_id);
809 
810 int transport_dump_vpd_assoc(
811 	struct t10_vpd *vpd,
812 	unsigned char *p_buf,
813 	int p_buf_len)
814 {
815 	unsigned char buf[VPD_TMP_BUF_SIZE];
816 	int ret = 0;
817 	int len;
818 
819 	memset(buf, 0, VPD_TMP_BUF_SIZE);
820 	len = sprintf(buf, "T10 VPD Identifier Association: ");
821 
822 	switch (vpd->association) {
823 	case 0x00:
824 		sprintf(buf+len, "addressed logical unit\n");
825 		break;
826 	case 0x10:
827 		sprintf(buf+len, "target port\n");
828 		break;
829 	case 0x20:
830 		sprintf(buf+len, "SCSI target device\n");
831 		break;
832 	default:
833 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
834 		ret = -EINVAL;
835 		break;
836 	}
837 
838 	if (p_buf)
839 		strncpy(p_buf, buf, p_buf_len);
840 	else
841 		pr_debug("%s", buf);
842 
843 	return ret;
844 }
845 
846 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
847 {
848 	/*
849 	 * The VPD identification association..
850 	 *
851 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
852 	 */
853 	vpd->association = (page_83[1] & 0x30);
854 	return transport_dump_vpd_assoc(vpd, NULL, 0);
855 }
856 EXPORT_SYMBOL(transport_set_vpd_assoc);
857 
858 int transport_dump_vpd_ident_type(
859 	struct t10_vpd *vpd,
860 	unsigned char *p_buf,
861 	int p_buf_len)
862 {
863 	unsigned char buf[VPD_TMP_BUF_SIZE];
864 	int ret = 0;
865 	int len;
866 
867 	memset(buf, 0, VPD_TMP_BUF_SIZE);
868 	len = sprintf(buf, "T10 VPD Identifier Type: ");
869 
870 	switch (vpd->device_identifier_type) {
871 	case 0x00:
872 		sprintf(buf+len, "Vendor specific\n");
873 		break;
874 	case 0x01:
875 		sprintf(buf+len, "T10 Vendor ID based\n");
876 		break;
877 	case 0x02:
878 		sprintf(buf+len, "EUI-64 based\n");
879 		break;
880 	case 0x03:
881 		sprintf(buf+len, "NAA\n");
882 		break;
883 	case 0x04:
884 		sprintf(buf+len, "Relative target port identifier\n");
885 		break;
886 	case 0x08:
887 		sprintf(buf+len, "SCSI name string\n");
888 		break;
889 	default:
890 		sprintf(buf+len, "Unsupported: 0x%02x\n",
891 				vpd->device_identifier_type);
892 		ret = -EINVAL;
893 		break;
894 	}
895 
896 	if (p_buf) {
897 		if (p_buf_len < strlen(buf)+1)
898 			return -EINVAL;
899 		strncpy(p_buf, buf, p_buf_len);
900 	} else {
901 		pr_debug("%s", buf);
902 	}
903 
904 	return ret;
905 }
906 
907 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
908 {
909 	/*
910 	 * The VPD identifier type..
911 	 *
912 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
913 	 */
914 	vpd->device_identifier_type = (page_83[1] & 0x0f);
915 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
916 }
917 EXPORT_SYMBOL(transport_set_vpd_ident_type);
918 
919 int transport_dump_vpd_ident(
920 	struct t10_vpd *vpd,
921 	unsigned char *p_buf,
922 	int p_buf_len)
923 {
924 	unsigned char buf[VPD_TMP_BUF_SIZE];
925 	int ret = 0;
926 
927 	memset(buf, 0, VPD_TMP_BUF_SIZE);
928 
929 	switch (vpd->device_identifier_code_set) {
930 	case 0x01: /* Binary */
931 		sprintf(buf, "T10 VPD Binary Device Identifier: %s\n",
932 			&vpd->device_identifier[0]);
933 		break;
934 	case 0x02: /* ASCII */
935 		sprintf(buf, "T10 VPD ASCII Device Identifier: %s\n",
936 			&vpd->device_identifier[0]);
937 		break;
938 	case 0x03: /* UTF-8 */
939 		sprintf(buf, "T10 VPD UTF-8 Device Identifier: %s\n",
940 			&vpd->device_identifier[0]);
941 		break;
942 	default:
943 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
944 			" 0x%02x", vpd->device_identifier_code_set);
945 		ret = -EINVAL;
946 		break;
947 	}
948 
949 	if (p_buf)
950 		strncpy(p_buf, buf, p_buf_len);
951 	else
952 		pr_debug("%s", buf);
953 
954 	return ret;
955 }
956 
957 int
958 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
959 {
960 	static const char hex_str[] = "0123456789abcdef";
961 	int j = 0, i = 4; /* offset to start of the identifier */
962 
963 	/*
964 	 * The VPD Code Set (encoding)
965 	 *
966 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
967 	 */
968 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
969 	switch (vpd->device_identifier_code_set) {
970 	case 0x01: /* Binary */
971 		vpd->device_identifier[j++] =
972 				hex_str[vpd->device_identifier_type];
973 		while (i < (4 + page_83[3])) {
974 			vpd->device_identifier[j++] =
975 				hex_str[(page_83[i] & 0xf0) >> 4];
976 			vpd->device_identifier[j++] =
977 				hex_str[page_83[i] & 0x0f];
978 			i++;
979 		}
980 		break;
981 	case 0x02: /* ASCII */
982 	case 0x03: /* UTF-8 */
983 		while (i < (4 + page_83[3]))
984 			vpd->device_identifier[j++] = page_83[i++];
985 		break;
986 	default:
987 		break;
988 	}
989 
990 	return transport_dump_vpd_ident(vpd, NULL, 0);
991 }
992 EXPORT_SYMBOL(transport_set_vpd_ident);
993 
994 static void core_setup_task_attr_emulation(struct se_device *dev)
995 {
996 	/*
997 	 * If this device is from Target_Core_Mod/pSCSI, disable the
998 	 * SAM Task Attribute emulation.
999 	 *
1000 	 * This is currently not available in upsream Linux/SCSI Target
1001 	 * mode code, and is assumed to be disabled while using TCM/pSCSI.
1002 	 */
1003 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
1004 		dev->dev_task_attr_type = SAM_TASK_ATTR_PASSTHROUGH;
1005 		return;
1006 	}
1007 
1008 	dev->dev_task_attr_type = SAM_TASK_ATTR_EMULATED;
1009 	pr_debug("%s: Using SAM_TASK_ATTR_EMULATED for SPC: 0x%02x"
1010 		" device\n", dev->transport->name,
1011 		dev->transport->get_device_rev(dev));
1012 }
1013 
1014 static void scsi_dump_inquiry(struct se_device *dev)
1015 {
1016 	struct t10_wwn *wwn = &dev->se_sub_dev->t10_wwn;
1017 	char buf[17];
1018 	int i, device_type;
1019 	/*
1020 	 * Print Linux/SCSI style INQUIRY formatting to the kernel ring buffer
1021 	 */
1022 	for (i = 0; i < 8; i++)
1023 		if (wwn->vendor[i] >= 0x20)
1024 			buf[i] = wwn->vendor[i];
1025 		else
1026 			buf[i] = ' ';
1027 	buf[i] = '\0';
1028 	pr_debug("  Vendor: %s\n", buf);
1029 
1030 	for (i = 0; i < 16; i++)
1031 		if (wwn->model[i] >= 0x20)
1032 			buf[i] = wwn->model[i];
1033 		else
1034 			buf[i] = ' ';
1035 	buf[i] = '\0';
1036 	pr_debug("  Model: %s\n", buf);
1037 
1038 	for (i = 0; i < 4; i++)
1039 		if (wwn->revision[i] >= 0x20)
1040 			buf[i] = wwn->revision[i];
1041 		else
1042 			buf[i] = ' ';
1043 	buf[i] = '\0';
1044 	pr_debug("  Revision: %s\n", buf);
1045 
1046 	device_type = dev->transport->get_device_type(dev);
1047 	pr_debug("  Type:   %s ", scsi_device_type(device_type));
1048 	pr_debug("                 ANSI SCSI revision: %02x\n",
1049 				dev->transport->get_device_rev(dev));
1050 }
1051 
1052 struct se_device *transport_add_device_to_core_hba(
1053 	struct se_hba *hba,
1054 	struct se_subsystem_api *transport,
1055 	struct se_subsystem_dev *se_dev,
1056 	u32 device_flags,
1057 	void *transport_dev,
1058 	struct se_dev_limits *dev_limits,
1059 	const char *inquiry_prod,
1060 	const char *inquiry_rev)
1061 {
1062 	int force_pt;
1063 	struct se_device  *dev;
1064 
1065 	dev = kzalloc(sizeof(struct se_device), GFP_KERNEL);
1066 	if (!dev) {
1067 		pr_err("Unable to allocate memory for se_dev_t\n");
1068 		return NULL;
1069 	}
1070 
1071 	dev->dev_flags		= device_flags;
1072 	dev->dev_status		|= TRANSPORT_DEVICE_DEACTIVATED;
1073 	dev->dev_ptr		= transport_dev;
1074 	dev->se_hba		= hba;
1075 	dev->se_sub_dev		= se_dev;
1076 	dev->transport		= transport;
1077 	INIT_LIST_HEAD(&dev->dev_list);
1078 	INIT_LIST_HEAD(&dev->dev_sep_list);
1079 	INIT_LIST_HEAD(&dev->dev_tmr_list);
1080 	INIT_LIST_HEAD(&dev->delayed_cmd_list);
1081 	INIT_LIST_HEAD(&dev->state_list);
1082 	INIT_LIST_HEAD(&dev->qf_cmd_list);
1083 	spin_lock_init(&dev->execute_task_lock);
1084 	spin_lock_init(&dev->delayed_cmd_lock);
1085 	spin_lock_init(&dev->dev_reservation_lock);
1086 	spin_lock_init(&dev->dev_status_lock);
1087 	spin_lock_init(&dev->se_port_lock);
1088 	spin_lock_init(&dev->se_tmr_lock);
1089 	spin_lock_init(&dev->qf_cmd_lock);
1090 	atomic_set(&dev->dev_ordered_id, 0);
1091 
1092 	se_dev_set_default_attribs(dev, dev_limits);
1093 
1094 	dev->dev_index = scsi_get_new_index(SCSI_DEVICE_INDEX);
1095 	dev->creation_time = get_jiffies_64();
1096 	spin_lock_init(&dev->stats_lock);
1097 
1098 	spin_lock(&hba->device_lock);
1099 	list_add_tail(&dev->dev_list, &hba->hba_dev_list);
1100 	hba->dev_count++;
1101 	spin_unlock(&hba->device_lock);
1102 	/*
1103 	 * Setup the SAM Task Attribute emulation for struct se_device
1104 	 */
1105 	core_setup_task_attr_emulation(dev);
1106 	/*
1107 	 * Force PR and ALUA passthrough emulation with internal object use.
1108 	 */
1109 	force_pt = (hba->hba_flags & HBA_FLAGS_INTERNAL_USE);
1110 	/*
1111 	 * Setup the Reservations infrastructure for struct se_device
1112 	 */
1113 	core_setup_reservations(dev, force_pt);
1114 	/*
1115 	 * Setup the Asymmetric Logical Unit Assignment for struct se_device
1116 	 */
1117 	if (core_setup_alua(dev, force_pt) < 0)
1118 		goto err_dev_list;
1119 
1120 	/*
1121 	 * Startup the struct se_device processing thread
1122 	 */
1123 	dev->tmr_wq = alloc_workqueue("tmr-%s", WQ_MEM_RECLAIM | WQ_UNBOUND, 1,
1124 				      dev->transport->name);
1125 	if (!dev->tmr_wq) {
1126 		pr_err("Unable to create tmr workqueue for %s\n",
1127 			dev->transport->name);
1128 		goto err_dev_list;
1129 	}
1130 	/*
1131 	 * Setup work_queue for QUEUE_FULL
1132 	 */
1133 	INIT_WORK(&dev->qf_work_queue, target_qf_do_work);
1134 	/*
1135 	 * Preload the initial INQUIRY const values if we are doing
1136 	 * anything virtual (IBLOCK, FILEIO, RAMDISK), but not for TCM/pSCSI
1137 	 * passthrough because this is being provided by the backend LLD.
1138 	 * This is required so that transport_get_inquiry() copies these
1139 	 * originals once back into DEV_T10_WWN(dev) for the virtual device
1140 	 * setup.
1141 	 */
1142 	if (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV) {
1143 		if (!inquiry_prod || !inquiry_rev) {
1144 			pr_err("All non TCM/pSCSI plugins require"
1145 				" INQUIRY consts\n");
1146 			goto err_wq;
1147 		}
1148 
1149 		strncpy(&dev->se_sub_dev->t10_wwn.vendor[0], "LIO-ORG", 8);
1150 		strncpy(&dev->se_sub_dev->t10_wwn.model[0], inquiry_prod, 16);
1151 		strncpy(&dev->se_sub_dev->t10_wwn.revision[0], inquiry_rev, 4);
1152 	}
1153 	scsi_dump_inquiry(dev);
1154 
1155 	return dev;
1156 
1157 err_wq:
1158 	destroy_workqueue(dev->tmr_wq);
1159 err_dev_list:
1160 	spin_lock(&hba->device_lock);
1161 	list_del(&dev->dev_list);
1162 	hba->dev_count--;
1163 	spin_unlock(&hba->device_lock);
1164 
1165 	se_release_vpd_for_dev(dev);
1166 
1167 	kfree(dev);
1168 
1169 	return NULL;
1170 }
1171 EXPORT_SYMBOL(transport_add_device_to_core_hba);
1172 
1173 int target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1174 {
1175 	struct se_device *dev = cmd->se_dev;
1176 
1177 	if (cmd->unknown_data_length) {
1178 		cmd->data_length = size;
1179 	} else if (size != cmd->data_length) {
1180 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1181 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1182 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1183 				cmd->data_length, size, cmd->t_task_cdb[0]);
1184 
1185 		if (cmd->data_direction == DMA_TO_DEVICE) {
1186 			pr_err("Rejecting underflow/overflow"
1187 					" WRITE data\n");
1188 			goto out_invalid_cdb_field;
1189 		}
1190 		/*
1191 		 * Reject READ_* or WRITE_* with overflow/underflow for
1192 		 * type SCF_SCSI_DATA_CDB.
1193 		 */
1194 		if (dev->se_sub_dev->se_dev_attrib.block_size != 512)  {
1195 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1196 				" CDB on non 512-byte sector setup subsystem"
1197 				" plugin: %s\n", dev->transport->name);
1198 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1199 			goto out_invalid_cdb_field;
1200 		}
1201 		/*
1202 		 * For the overflow case keep the existing fabric provided
1203 		 * ->data_length.  Otherwise for the underflow case, reset
1204 		 * ->data_length to the smaller SCSI expected data transfer
1205 		 * length.
1206 		 */
1207 		if (size > cmd->data_length) {
1208 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1209 			cmd->residual_count = (size - cmd->data_length);
1210 		} else {
1211 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1212 			cmd->residual_count = (cmd->data_length - size);
1213 			cmd->data_length = size;
1214 		}
1215 	}
1216 
1217 	return 0;
1218 
1219 out_invalid_cdb_field:
1220 	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1221 	cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1222 	return -EINVAL;
1223 }
1224 
1225 /*
1226  * Used by fabric modules containing a local struct se_cmd within their
1227  * fabric dependent per I/O descriptor.
1228  */
1229 void transport_init_se_cmd(
1230 	struct se_cmd *cmd,
1231 	struct target_core_fabric_ops *tfo,
1232 	struct se_session *se_sess,
1233 	u32 data_length,
1234 	int data_direction,
1235 	int task_attr,
1236 	unsigned char *sense_buffer)
1237 {
1238 	INIT_LIST_HEAD(&cmd->se_lun_node);
1239 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1240 	INIT_LIST_HEAD(&cmd->se_qf_node);
1241 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1242 	INIT_LIST_HEAD(&cmd->state_list);
1243 	init_completion(&cmd->transport_lun_fe_stop_comp);
1244 	init_completion(&cmd->transport_lun_stop_comp);
1245 	init_completion(&cmd->t_transport_stop_comp);
1246 	init_completion(&cmd->cmd_wait_comp);
1247 	init_completion(&cmd->task_stop_comp);
1248 	spin_lock_init(&cmd->t_state_lock);
1249 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1250 
1251 	cmd->se_tfo = tfo;
1252 	cmd->se_sess = se_sess;
1253 	cmd->data_length = data_length;
1254 	cmd->data_direction = data_direction;
1255 	cmd->sam_task_attr = task_attr;
1256 	cmd->sense_buffer = sense_buffer;
1257 
1258 	cmd->state_active = false;
1259 }
1260 EXPORT_SYMBOL(transport_init_se_cmd);
1261 
1262 static int transport_check_alloc_task_attr(struct se_cmd *cmd)
1263 {
1264 	/*
1265 	 * Check if SAM Task Attribute emulation is enabled for this
1266 	 * struct se_device storage object
1267 	 */
1268 	if (cmd->se_dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED)
1269 		return 0;
1270 
1271 	if (cmd->sam_task_attr == MSG_ACA_TAG) {
1272 		pr_debug("SAM Task Attribute ACA"
1273 			" emulation is not supported\n");
1274 		return -EINVAL;
1275 	}
1276 	/*
1277 	 * Used to determine when ORDERED commands should go from
1278 	 * Dormant to Active status.
1279 	 */
1280 	cmd->se_ordered_id = atomic_inc_return(&cmd->se_dev->dev_ordered_id);
1281 	smp_mb__after_atomic_inc();
1282 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1283 			cmd->se_ordered_id, cmd->sam_task_attr,
1284 			cmd->se_dev->transport->name);
1285 	return 0;
1286 }
1287 
1288 /*	target_setup_cmd_from_cdb():
1289  *
1290  *	Called from fabric RX Thread.
1291  */
1292 int target_setup_cmd_from_cdb(
1293 	struct se_cmd *cmd,
1294 	unsigned char *cdb)
1295 {
1296 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
1297 	u32 pr_reg_type = 0;
1298 	u8 alua_ascq = 0;
1299 	unsigned long flags;
1300 	int ret;
1301 
1302 	/*
1303 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1304 	 * for VARIABLE_LENGTH_CMD
1305 	 */
1306 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1307 		pr_err("Received SCSI CDB with command_size: %d that"
1308 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1309 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1310 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1311 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1312 		return -EINVAL;
1313 	}
1314 	/*
1315 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1316 	 * allocate the additional extended CDB buffer now..  Otherwise
1317 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1318 	 */
1319 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1320 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1321 						GFP_KERNEL);
1322 		if (!cmd->t_task_cdb) {
1323 			pr_err("Unable to allocate cmd->t_task_cdb"
1324 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1325 				scsi_command_size(cdb),
1326 				(unsigned long)sizeof(cmd->__t_task_cdb));
1327 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1328 			cmd->scsi_sense_reason =
1329 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1330 			return -ENOMEM;
1331 		}
1332 	} else
1333 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1334 	/*
1335 	 * Copy the original CDB into cmd->
1336 	 */
1337 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1338 
1339 	/*
1340 	 * Check for an existing UNIT ATTENTION condition
1341 	 */
1342 	if (core_scsi3_ua_check(cmd, cdb) < 0) {
1343 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1344 		cmd->scsi_sense_reason = TCM_CHECK_CONDITION_UNIT_ATTENTION;
1345 		return -EINVAL;
1346 	}
1347 
1348 	ret = su_dev->t10_alua.alua_state_check(cmd, cdb, &alua_ascq);
1349 	if (ret != 0) {
1350 		/*
1351 		 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
1352 		 * The ALUA additional sense code qualifier (ASCQ) is determined
1353 		 * by the ALUA primary or secondary access state..
1354 		 */
1355 		if (ret > 0) {
1356 			pr_debug("[%s]: ALUA TG Port not available, "
1357 				"SenseKey: NOT_READY, ASC/ASCQ: "
1358 				"0x04/0x%02x\n",
1359 				cmd->se_tfo->get_fabric_name(), alua_ascq);
1360 
1361 			transport_set_sense_codes(cmd, 0x04, alua_ascq);
1362 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1363 			cmd->scsi_sense_reason = TCM_CHECK_CONDITION_NOT_READY;
1364 			return -EINVAL;
1365 		}
1366 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1367 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1368 		return -EINVAL;
1369 	}
1370 
1371 	/*
1372 	 * Check status for SPC-3 Persistent Reservations
1373 	 */
1374 	if (su_dev->t10_pr.pr_ops.t10_reservation_check(cmd, &pr_reg_type)) {
1375 		if (su_dev->t10_pr.pr_ops.t10_seq_non_holder(
1376 					cmd, cdb, pr_reg_type) != 0) {
1377 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1378 			cmd->se_cmd_flags |= SCF_SCSI_RESERVATION_CONFLICT;
1379 			cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1380 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
1381 			return -EBUSY;
1382 		}
1383 		/*
1384 		 * This means the CDB is allowed for the SCSI Initiator port
1385 		 * when said port is *NOT* holding the legacy SPC-2 or
1386 		 * SPC-3 Persistent Reservation.
1387 		 */
1388 	}
1389 
1390 	ret = cmd->se_dev->transport->parse_cdb(cmd);
1391 	if (ret < 0)
1392 		return ret;
1393 
1394 	spin_lock_irqsave(&cmd->t_state_lock, flags);
1395 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1396 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1397 
1398 	/*
1399 	 * Check for SAM Task Attribute Emulation
1400 	 */
1401 	if (transport_check_alloc_task_attr(cmd) < 0) {
1402 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1403 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1404 		return -EINVAL;
1405 	}
1406 	spin_lock(&cmd->se_lun->lun_sep_lock);
1407 	if (cmd->se_lun->lun_sep)
1408 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1409 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1410 	return 0;
1411 }
1412 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1413 
1414 /*
1415  * Used by fabric module frontends to queue tasks directly.
1416  * Many only be used from process context only
1417  */
1418 int transport_handle_cdb_direct(
1419 	struct se_cmd *cmd)
1420 {
1421 	int ret;
1422 
1423 	if (!cmd->se_lun) {
1424 		dump_stack();
1425 		pr_err("cmd->se_lun is NULL\n");
1426 		return -EINVAL;
1427 	}
1428 	if (in_interrupt()) {
1429 		dump_stack();
1430 		pr_err("transport_generic_handle_cdb cannot be called"
1431 				" from interrupt context\n");
1432 		return -EINVAL;
1433 	}
1434 	/*
1435 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1436 	 * outstanding descriptors are handled correctly during shutdown via
1437 	 * transport_wait_for_tasks()
1438 	 *
1439 	 * Also, we don't take cmd->t_state_lock here as we only expect
1440 	 * this to be called for initial descriptor submission.
1441 	 */
1442 	cmd->t_state = TRANSPORT_NEW_CMD;
1443 	cmd->transport_state |= CMD_T_ACTIVE;
1444 
1445 	/*
1446 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1447 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1448 	 * and call transport_generic_request_failure() if necessary..
1449 	 */
1450 	ret = transport_generic_new_cmd(cmd);
1451 	if (ret < 0)
1452 		transport_generic_request_failure(cmd);
1453 
1454 	return 0;
1455 }
1456 EXPORT_SYMBOL(transport_handle_cdb_direct);
1457 
1458 /*
1459  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1460  * 			 se_cmd + use pre-allocated SGL memory.
1461  *
1462  * @se_cmd: command descriptor to submit
1463  * @se_sess: associated se_sess for endpoint
1464  * @cdb: pointer to SCSI CDB
1465  * @sense: pointer to SCSI sense buffer
1466  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1467  * @data_length: fabric expected data transfer length
1468  * @task_addr: SAM task attribute
1469  * @data_dir: DMA data direction
1470  * @flags: flags for command submission from target_sc_flags_tables
1471  * @sgl: struct scatterlist memory for unidirectional mapping
1472  * @sgl_count: scatterlist count for unidirectional mapping
1473  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1474  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1475  *
1476  * Returns non zero to signal active I/O shutdown failure.  All other
1477  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1478  * but still return zero here.
1479  *
1480  * This may only be called from process context, and also currently
1481  * assumes internal allocation of fabric payload buffer by target-core.
1482  */
1483 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1484 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1485 		u32 data_length, int task_attr, int data_dir, int flags,
1486 		struct scatterlist *sgl, u32 sgl_count,
1487 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1488 {
1489 	struct se_portal_group *se_tpg;
1490 	int rc;
1491 
1492 	se_tpg = se_sess->se_tpg;
1493 	BUG_ON(!se_tpg);
1494 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1495 	BUG_ON(in_interrupt());
1496 	/*
1497 	 * Initialize se_cmd for target operation.  From this point
1498 	 * exceptions are handled by sending exception status via
1499 	 * target_core_fabric_ops->queue_status() callback
1500 	 */
1501 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1502 				data_length, data_dir, task_attr, sense);
1503 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1504 		se_cmd->unknown_data_length = 1;
1505 	/*
1506 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1507 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1508 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1509 	 * kref_put() to happen during fabric packet acknowledgement.
1510 	 */
1511 	rc = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1512 	if (rc)
1513 		return rc;
1514 	/*
1515 	 * Signal bidirectional data payloads to target-core
1516 	 */
1517 	if (flags & TARGET_SCF_BIDI_OP)
1518 		se_cmd->se_cmd_flags |= SCF_BIDI;
1519 	/*
1520 	 * Locate se_lun pointer and attach it to struct se_cmd
1521 	 */
1522 	if (transport_lookup_cmd_lun(se_cmd, unpacked_lun) < 0) {
1523 		transport_send_check_condition_and_sense(se_cmd,
1524 				se_cmd->scsi_sense_reason, 0);
1525 		target_put_sess_cmd(se_sess, se_cmd);
1526 		return 0;
1527 	}
1528 
1529 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1530 	if (rc != 0) {
1531 		transport_generic_request_failure(se_cmd);
1532 		return 0;
1533 	}
1534 	/*
1535 	 * When a non zero sgl_count has been passed perform SGL passthrough
1536 	 * mapping for pre-allocated fabric memory instead of having target
1537 	 * core perform an internal SGL allocation..
1538 	 */
1539 	if (sgl_count != 0) {
1540 		BUG_ON(!sgl);
1541 
1542 		/*
1543 		 * A work-around for tcm_loop as some userspace code via
1544 		 * scsi-generic do not memset their associated read buffers,
1545 		 * so go ahead and do that here for type non-data CDBs.  Also
1546 		 * note that this is currently guaranteed to be a single SGL
1547 		 * for this case by target core in target_setup_cmd_from_cdb()
1548 		 * -> transport_generic_cmd_sequencer().
1549 		 */
1550 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1551 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1552 			unsigned char *buf = NULL;
1553 
1554 			if (sgl)
1555 				buf = kmap(sg_page(sgl)) + sgl->offset;
1556 
1557 			if (buf) {
1558 				memset(buf, 0, sgl->length);
1559 				kunmap(sg_page(sgl));
1560 			}
1561 		}
1562 
1563 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1564 				sgl_bidi, sgl_bidi_count);
1565 		if (rc != 0) {
1566 			transport_generic_request_failure(se_cmd);
1567 			return 0;
1568 		}
1569 	}
1570 	/*
1571 	 * Check if we need to delay processing because of ALUA
1572 	 * Active/NonOptimized primary access state..
1573 	 */
1574 	core_alua_check_nonop_delay(se_cmd);
1575 
1576 	transport_handle_cdb_direct(se_cmd);
1577 	return 0;
1578 }
1579 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1580 
1581 /*
1582  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1583  *
1584  * @se_cmd: command descriptor to submit
1585  * @se_sess: associated se_sess for endpoint
1586  * @cdb: pointer to SCSI CDB
1587  * @sense: pointer to SCSI sense buffer
1588  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1589  * @data_length: fabric expected data transfer length
1590  * @task_addr: SAM task attribute
1591  * @data_dir: DMA data direction
1592  * @flags: flags for command submission from target_sc_flags_tables
1593  *
1594  * Returns non zero to signal active I/O shutdown failure.  All other
1595  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1596  * but still return zero here.
1597  *
1598  * This may only be called from process context, and also currently
1599  * assumes internal allocation of fabric payload buffer by target-core.
1600  *
1601  * It also assumes interal target core SGL memory allocation.
1602  */
1603 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1604 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1605 		u32 data_length, int task_attr, int data_dir, int flags)
1606 {
1607 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1608 			unpacked_lun, data_length, task_attr, data_dir,
1609 			flags, NULL, 0, NULL, 0);
1610 }
1611 EXPORT_SYMBOL(target_submit_cmd);
1612 
1613 static void target_complete_tmr_failure(struct work_struct *work)
1614 {
1615 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1616 
1617 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1618 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1619 	transport_generic_free_cmd(se_cmd, 0);
1620 }
1621 
1622 /**
1623  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1624  *                     for TMR CDBs
1625  *
1626  * @se_cmd: command descriptor to submit
1627  * @se_sess: associated se_sess for endpoint
1628  * @sense: pointer to SCSI sense buffer
1629  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1630  * @fabric_context: fabric context for TMR req
1631  * @tm_type: Type of TM request
1632  * @gfp: gfp type for caller
1633  * @tag: referenced task tag for TMR_ABORT_TASK
1634  * @flags: submit cmd flags
1635  *
1636  * Callable from all contexts.
1637  **/
1638 
1639 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1640 		unsigned char *sense, u32 unpacked_lun,
1641 		void *fabric_tmr_ptr, unsigned char tm_type,
1642 		gfp_t gfp, unsigned int tag, int flags)
1643 {
1644 	struct se_portal_group *se_tpg;
1645 	int ret;
1646 
1647 	se_tpg = se_sess->se_tpg;
1648 	BUG_ON(!se_tpg);
1649 
1650 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1651 			      0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1652 	/*
1653 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1654 	 * allocation failure.
1655 	 */
1656 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1657 	if (ret < 0)
1658 		return -ENOMEM;
1659 
1660 	if (tm_type == TMR_ABORT_TASK)
1661 		se_cmd->se_tmr_req->ref_task_tag = tag;
1662 
1663 	/* See target_submit_cmd for commentary */
1664 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1665 	if (ret) {
1666 		core_tmr_release_req(se_cmd->se_tmr_req);
1667 		return ret;
1668 	}
1669 
1670 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1671 	if (ret) {
1672 		/*
1673 		 * For callback during failure handling, push this work off
1674 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1675 		 */
1676 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1677 		schedule_work(&se_cmd->work);
1678 		return 0;
1679 	}
1680 	transport_generic_handle_tmr(se_cmd);
1681 	return 0;
1682 }
1683 EXPORT_SYMBOL(target_submit_tmr);
1684 
1685 /*
1686  * If the cmd is active, request it to be stopped and sleep until it
1687  * has completed.
1688  */
1689 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1690 {
1691 	bool was_active = false;
1692 
1693 	if (cmd->transport_state & CMD_T_BUSY) {
1694 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1695 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1696 
1697 		pr_debug("cmd %p waiting to complete\n", cmd);
1698 		wait_for_completion(&cmd->task_stop_comp);
1699 		pr_debug("cmd %p stopped successfully\n", cmd);
1700 
1701 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1702 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1703 		cmd->transport_state &= ~CMD_T_BUSY;
1704 		was_active = true;
1705 	}
1706 
1707 	return was_active;
1708 }
1709 
1710 /*
1711  * Handle SAM-esque emulation for generic transport request failures.
1712  */
1713 void transport_generic_request_failure(struct se_cmd *cmd)
1714 {
1715 	int ret = 0;
1716 
1717 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1718 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1719 		cmd->t_task_cdb[0]);
1720 	pr_debug("-----[ i_state: %d t_state: %d scsi_sense_reason: %d\n",
1721 		cmd->se_tfo->get_cmd_state(cmd),
1722 		cmd->t_state, cmd->scsi_sense_reason);
1723 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1724 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1725 		(cmd->transport_state & CMD_T_STOP) != 0,
1726 		(cmd->transport_state & CMD_T_SENT) != 0);
1727 
1728 	/*
1729 	 * For SAM Task Attribute emulation for failed struct se_cmd
1730 	 */
1731 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1732 		transport_complete_task_attr(cmd);
1733 
1734 	switch (cmd->scsi_sense_reason) {
1735 	case TCM_NON_EXISTENT_LUN:
1736 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1737 	case TCM_INVALID_CDB_FIELD:
1738 	case TCM_INVALID_PARAMETER_LIST:
1739 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1740 	case TCM_UNKNOWN_MODE_PAGE:
1741 	case TCM_WRITE_PROTECTED:
1742 	case TCM_ADDRESS_OUT_OF_RANGE:
1743 	case TCM_CHECK_CONDITION_ABORT_CMD:
1744 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1745 	case TCM_CHECK_CONDITION_NOT_READY:
1746 		break;
1747 	case TCM_RESERVATION_CONFLICT:
1748 		/*
1749 		 * No SENSE Data payload for this case, set SCSI Status
1750 		 * and queue the response to $FABRIC_MOD.
1751 		 *
1752 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1753 		 */
1754 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1755 		/*
1756 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1757 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1758 		 * CONFLICT STATUS.
1759 		 *
1760 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1761 		 */
1762 		if (cmd->se_sess &&
1763 		    cmd->se_dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl == 2)
1764 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1765 				cmd->orig_fe_lun, 0x2C,
1766 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1767 
1768 		ret = cmd->se_tfo->queue_status(cmd);
1769 		if (ret == -EAGAIN || ret == -ENOMEM)
1770 			goto queue_full;
1771 		goto check_stop;
1772 	default:
1773 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1774 			cmd->t_task_cdb[0], cmd->scsi_sense_reason);
1775 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1776 		break;
1777 	}
1778 
1779 	ret = transport_send_check_condition_and_sense(cmd,
1780 			cmd->scsi_sense_reason, 0);
1781 	if (ret == -EAGAIN || ret == -ENOMEM)
1782 		goto queue_full;
1783 
1784 check_stop:
1785 	transport_lun_remove_cmd(cmd);
1786 	if (!transport_cmd_check_stop_to_fabric(cmd))
1787 		;
1788 	return;
1789 
1790 queue_full:
1791 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1792 	transport_handle_queue_full(cmd, cmd->se_dev);
1793 }
1794 EXPORT_SYMBOL(transport_generic_request_failure);
1795 
1796 static void __target_execute_cmd(struct se_cmd *cmd)
1797 {
1798 	int error = 0;
1799 
1800 	spin_lock_irq(&cmd->t_state_lock);
1801 	cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
1802 	spin_unlock_irq(&cmd->t_state_lock);
1803 
1804 	if (cmd->execute_cmd)
1805 		error = cmd->execute_cmd(cmd);
1806 
1807 	if (error) {
1808 		spin_lock_irq(&cmd->t_state_lock);
1809 		cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1810 		spin_unlock_irq(&cmd->t_state_lock);
1811 
1812 		transport_generic_request_failure(cmd);
1813 	}
1814 }
1815 
1816 void target_execute_cmd(struct se_cmd *cmd)
1817 {
1818 	struct se_device *dev = cmd->se_dev;
1819 
1820 	/*
1821 	 * If the received CDB has aleady been aborted stop processing it here.
1822 	 */
1823 	if (transport_check_aborted_status(cmd, 1))
1824 		return;
1825 
1826 	/*
1827 	 * Determine if IOCTL context caller in requesting the stopping of this
1828 	 * command for LUN shutdown purposes.
1829 	 */
1830 	spin_lock_irq(&cmd->t_state_lock);
1831 	if (cmd->transport_state & CMD_T_LUN_STOP) {
1832 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
1833 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
1834 
1835 		cmd->transport_state &= ~CMD_T_ACTIVE;
1836 		spin_unlock_irq(&cmd->t_state_lock);
1837 		complete(&cmd->transport_lun_stop_comp);
1838 		return;
1839 	}
1840 	/*
1841 	 * Determine if frontend context caller is requesting the stopping of
1842 	 * this command for frontend exceptions.
1843 	 */
1844 	if (cmd->transport_state & CMD_T_STOP) {
1845 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1846 			__func__, __LINE__,
1847 			cmd->se_tfo->get_task_tag(cmd));
1848 
1849 		spin_unlock_irq(&cmd->t_state_lock);
1850 		complete(&cmd->t_transport_stop_comp);
1851 		return;
1852 	}
1853 
1854 	cmd->t_state = TRANSPORT_PROCESSING;
1855 	spin_unlock_irq(&cmd->t_state_lock);
1856 
1857 	if (dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED)
1858 		goto execute;
1859 
1860 	/*
1861 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1862 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1863 	 */
1864 	switch (cmd->sam_task_attr) {
1865 	case MSG_HEAD_TAG:
1866 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1867 			 "se_ordered_id: %u\n",
1868 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1869 		goto execute;
1870 	case MSG_ORDERED_TAG:
1871 		atomic_inc(&dev->dev_ordered_sync);
1872 		smp_mb__after_atomic_inc();
1873 
1874 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1875 			 " se_ordered_id: %u\n",
1876 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1877 
1878 		/*
1879 		 * Execute an ORDERED command if no other older commands
1880 		 * exist that need to be completed first.
1881 		 */
1882 		if (!atomic_read(&dev->simple_cmds))
1883 			goto execute;
1884 		break;
1885 	default:
1886 		/*
1887 		 * For SIMPLE and UNTAGGED Task Attribute commands
1888 		 */
1889 		atomic_inc(&dev->simple_cmds);
1890 		smp_mb__after_atomic_inc();
1891 		break;
1892 	}
1893 
1894 	if (atomic_read(&dev->dev_ordered_sync) != 0) {
1895 		spin_lock(&dev->delayed_cmd_lock);
1896 		list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1897 		spin_unlock(&dev->delayed_cmd_lock);
1898 
1899 		pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1900 			" delayed CMD list, se_ordered_id: %u\n",
1901 			cmd->t_task_cdb[0], cmd->sam_task_attr,
1902 			cmd->se_ordered_id);
1903 		return;
1904 	}
1905 
1906 execute:
1907 	/*
1908 	 * Otherwise, no ORDERED task attributes exist..
1909 	 */
1910 	__target_execute_cmd(cmd);
1911 }
1912 EXPORT_SYMBOL(target_execute_cmd);
1913 
1914 /*
1915  * Process all commands up to the last received ORDERED task attribute which
1916  * requires another blocking boundary
1917  */
1918 static void target_restart_delayed_cmds(struct se_device *dev)
1919 {
1920 	for (;;) {
1921 		struct se_cmd *cmd;
1922 
1923 		spin_lock(&dev->delayed_cmd_lock);
1924 		if (list_empty(&dev->delayed_cmd_list)) {
1925 			spin_unlock(&dev->delayed_cmd_lock);
1926 			break;
1927 		}
1928 
1929 		cmd = list_entry(dev->delayed_cmd_list.next,
1930 				 struct se_cmd, se_delayed_node);
1931 		list_del(&cmd->se_delayed_node);
1932 		spin_unlock(&dev->delayed_cmd_lock);
1933 
1934 		__target_execute_cmd(cmd);
1935 
1936 		if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1937 			break;
1938 	}
1939 }
1940 
1941 /*
1942  * Called from I/O completion to determine which dormant/delayed
1943  * and ordered cmds need to have their tasks added to the execution queue.
1944  */
1945 static void transport_complete_task_attr(struct se_cmd *cmd)
1946 {
1947 	struct se_device *dev = cmd->se_dev;
1948 
1949 	if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1950 		atomic_dec(&dev->simple_cmds);
1951 		smp_mb__after_atomic_dec();
1952 		dev->dev_cur_ordered_id++;
1953 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1954 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1955 			cmd->se_ordered_id);
1956 	} else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1957 		dev->dev_cur_ordered_id++;
1958 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1959 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1960 			cmd->se_ordered_id);
1961 	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1962 		atomic_dec(&dev->dev_ordered_sync);
1963 		smp_mb__after_atomic_dec();
1964 
1965 		dev->dev_cur_ordered_id++;
1966 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1967 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1968 	}
1969 
1970 	target_restart_delayed_cmds(dev);
1971 }
1972 
1973 static void transport_complete_qf(struct se_cmd *cmd)
1974 {
1975 	int ret = 0;
1976 
1977 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1978 		transport_complete_task_attr(cmd);
1979 
1980 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1981 		ret = cmd->se_tfo->queue_status(cmd);
1982 		if (ret)
1983 			goto out;
1984 	}
1985 
1986 	switch (cmd->data_direction) {
1987 	case DMA_FROM_DEVICE:
1988 		ret = cmd->se_tfo->queue_data_in(cmd);
1989 		break;
1990 	case DMA_TO_DEVICE:
1991 		if (cmd->t_bidi_data_sg) {
1992 			ret = cmd->se_tfo->queue_data_in(cmd);
1993 			if (ret < 0)
1994 				break;
1995 		}
1996 		/* Fall through for DMA_TO_DEVICE */
1997 	case DMA_NONE:
1998 		ret = cmd->se_tfo->queue_status(cmd);
1999 		break;
2000 	default:
2001 		break;
2002 	}
2003 
2004 out:
2005 	if (ret < 0) {
2006 		transport_handle_queue_full(cmd, cmd->se_dev);
2007 		return;
2008 	}
2009 	transport_lun_remove_cmd(cmd);
2010 	transport_cmd_check_stop_to_fabric(cmd);
2011 }
2012 
2013 static void transport_handle_queue_full(
2014 	struct se_cmd *cmd,
2015 	struct se_device *dev)
2016 {
2017 	spin_lock_irq(&dev->qf_cmd_lock);
2018 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2019 	atomic_inc(&dev->dev_qf_count);
2020 	smp_mb__after_atomic_inc();
2021 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2022 
2023 	schedule_work(&cmd->se_dev->qf_work_queue);
2024 }
2025 
2026 static void target_complete_ok_work(struct work_struct *work)
2027 {
2028 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2029 	int ret;
2030 
2031 	/*
2032 	 * Check if we need to move delayed/dormant tasks from cmds on the
2033 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2034 	 * Attribute.
2035 	 */
2036 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
2037 		transport_complete_task_attr(cmd);
2038 	/*
2039 	 * Check to schedule QUEUE_FULL work, or execute an existing
2040 	 * cmd->transport_qf_callback()
2041 	 */
2042 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2043 		schedule_work(&cmd->se_dev->qf_work_queue);
2044 
2045 	/*
2046 	 * Check if we need to send a sense buffer from
2047 	 * the struct se_cmd in question.
2048 	 */
2049 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2050 		WARN_ON(!cmd->scsi_status);
2051 		ret = transport_send_check_condition_and_sense(
2052 					cmd, 0, 1);
2053 		if (ret == -EAGAIN || ret == -ENOMEM)
2054 			goto queue_full;
2055 
2056 		transport_lun_remove_cmd(cmd);
2057 		transport_cmd_check_stop_to_fabric(cmd);
2058 		return;
2059 	}
2060 	/*
2061 	 * Check for a callback, used by amongst other things
2062 	 * XDWRITE_READ_10 emulation.
2063 	 */
2064 	if (cmd->transport_complete_callback)
2065 		cmd->transport_complete_callback(cmd);
2066 
2067 	switch (cmd->data_direction) {
2068 	case DMA_FROM_DEVICE:
2069 		spin_lock(&cmd->se_lun->lun_sep_lock);
2070 		if (cmd->se_lun->lun_sep) {
2071 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2072 					cmd->data_length;
2073 		}
2074 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2075 
2076 		ret = cmd->se_tfo->queue_data_in(cmd);
2077 		if (ret == -EAGAIN || ret == -ENOMEM)
2078 			goto queue_full;
2079 		break;
2080 	case DMA_TO_DEVICE:
2081 		spin_lock(&cmd->se_lun->lun_sep_lock);
2082 		if (cmd->se_lun->lun_sep) {
2083 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2084 				cmd->data_length;
2085 		}
2086 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2087 		/*
2088 		 * Check if we need to send READ payload for BIDI-COMMAND
2089 		 */
2090 		if (cmd->t_bidi_data_sg) {
2091 			spin_lock(&cmd->se_lun->lun_sep_lock);
2092 			if (cmd->se_lun->lun_sep) {
2093 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2094 					cmd->data_length;
2095 			}
2096 			spin_unlock(&cmd->se_lun->lun_sep_lock);
2097 			ret = cmd->se_tfo->queue_data_in(cmd);
2098 			if (ret == -EAGAIN || ret == -ENOMEM)
2099 				goto queue_full;
2100 			break;
2101 		}
2102 		/* Fall through for DMA_TO_DEVICE */
2103 	case DMA_NONE:
2104 		ret = cmd->se_tfo->queue_status(cmd);
2105 		if (ret == -EAGAIN || ret == -ENOMEM)
2106 			goto queue_full;
2107 		break;
2108 	default:
2109 		break;
2110 	}
2111 
2112 	transport_lun_remove_cmd(cmd);
2113 	transport_cmd_check_stop_to_fabric(cmd);
2114 	return;
2115 
2116 queue_full:
2117 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2118 		" data_direction: %d\n", cmd, cmd->data_direction);
2119 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2120 	transport_handle_queue_full(cmd, cmd->se_dev);
2121 }
2122 
2123 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2124 {
2125 	struct scatterlist *sg;
2126 	int count;
2127 
2128 	for_each_sg(sgl, sg, nents, count)
2129 		__free_page(sg_page(sg));
2130 
2131 	kfree(sgl);
2132 }
2133 
2134 static inline void transport_free_pages(struct se_cmd *cmd)
2135 {
2136 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
2137 		return;
2138 
2139 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2140 	cmd->t_data_sg = NULL;
2141 	cmd->t_data_nents = 0;
2142 
2143 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2144 	cmd->t_bidi_data_sg = NULL;
2145 	cmd->t_bidi_data_nents = 0;
2146 }
2147 
2148 /**
2149  * transport_release_cmd - free a command
2150  * @cmd:       command to free
2151  *
2152  * This routine unconditionally frees a command, and reference counting
2153  * or list removal must be done in the caller.
2154  */
2155 static void transport_release_cmd(struct se_cmd *cmd)
2156 {
2157 	BUG_ON(!cmd->se_tfo);
2158 
2159 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2160 		core_tmr_release_req(cmd->se_tmr_req);
2161 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2162 		kfree(cmd->t_task_cdb);
2163 	/*
2164 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2165 	 * the kref and call ->release_cmd() in kref callback.
2166 	 */
2167 	 if (cmd->check_release != 0) {
2168 		target_put_sess_cmd(cmd->se_sess, cmd);
2169 		return;
2170 	}
2171 	cmd->se_tfo->release_cmd(cmd);
2172 }
2173 
2174 /**
2175  * transport_put_cmd - release a reference to a command
2176  * @cmd:       command to release
2177  *
2178  * This routine releases our reference to the command and frees it if possible.
2179  */
2180 static void transport_put_cmd(struct se_cmd *cmd)
2181 {
2182 	unsigned long flags;
2183 
2184 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2185 	if (atomic_read(&cmd->t_fe_count)) {
2186 		if (!atomic_dec_and_test(&cmd->t_fe_count))
2187 			goto out_busy;
2188 	}
2189 
2190 	if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
2191 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2192 		target_remove_from_state_list(cmd);
2193 	}
2194 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2195 
2196 	transport_free_pages(cmd);
2197 	transport_release_cmd(cmd);
2198 	return;
2199 out_busy:
2200 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2201 }
2202 
2203 /*
2204  * transport_generic_map_mem_to_cmd - Use fabric-alloced pages instead of
2205  * allocating in the core.
2206  * @cmd:  Associated se_cmd descriptor
2207  * @mem:  SGL style memory for TCM WRITE / READ
2208  * @sg_mem_num: Number of SGL elements
2209  * @mem_bidi_in: SGL style memory for TCM BIDI READ
2210  * @sg_mem_bidi_num: Number of BIDI READ SGL elements
2211  *
2212  * Return: nonzero return cmd was rejected for -ENOMEM or inproper usage
2213  * of parameters.
2214  */
2215 int transport_generic_map_mem_to_cmd(
2216 	struct se_cmd *cmd,
2217 	struct scatterlist *sgl,
2218 	u32 sgl_count,
2219 	struct scatterlist *sgl_bidi,
2220 	u32 sgl_bidi_count)
2221 {
2222 	if (!sgl || !sgl_count)
2223 		return 0;
2224 
2225 	/*
2226 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
2227 	 * scatterlists already have been set to follow what the fabric
2228 	 * passes for the original expected data transfer length.
2229 	 */
2230 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
2231 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
2232 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
2233 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
2234 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
2235 		return -EINVAL;
2236 	}
2237 
2238 	cmd->t_data_sg = sgl;
2239 	cmd->t_data_nents = sgl_count;
2240 
2241 	if (sgl_bidi && sgl_bidi_count) {
2242 		cmd->t_bidi_data_sg = sgl_bidi;
2243 		cmd->t_bidi_data_nents = sgl_bidi_count;
2244 	}
2245 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
2246 	return 0;
2247 }
2248 EXPORT_SYMBOL(transport_generic_map_mem_to_cmd);
2249 
2250 void *transport_kmap_data_sg(struct se_cmd *cmd)
2251 {
2252 	struct scatterlist *sg = cmd->t_data_sg;
2253 	struct page **pages;
2254 	int i;
2255 
2256 	/*
2257 	 * We need to take into account a possible offset here for fabrics like
2258 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2259 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2260 	 */
2261 	if (!cmd->t_data_nents)
2262 		return NULL;
2263 
2264 	BUG_ON(!sg);
2265 	if (cmd->t_data_nents == 1)
2266 		return kmap(sg_page(sg)) + sg->offset;
2267 
2268 	/* >1 page. use vmap */
2269 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2270 	if (!pages) {
2271 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2272 		return NULL;
2273 	}
2274 
2275 	/* convert sg[] to pages[] */
2276 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2277 		pages[i] = sg_page(sg);
2278 	}
2279 
2280 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2281 	kfree(pages);
2282 	if (!cmd->t_data_vmap) {
2283 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2284 		return NULL;
2285 	}
2286 
2287 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2288 }
2289 EXPORT_SYMBOL(transport_kmap_data_sg);
2290 
2291 void transport_kunmap_data_sg(struct se_cmd *cmd)
2292 {
2293 	if (!cmd->t_data_nents) {
2294 		return;
2295 	} else if (cmd->t_data_nents == 1) {
2296 		kunmap(sg_page(cmd->t_data_sg));
2297 		return;
2298 	}
2299 
2300 	vunmap(cmd->t_data_vmap);
2301 	cmd->t_data_vmap = NULL;
2302 }
2303 EXPORT_SYMBOL(transport_kunmap_data_sg);
2304 
2305 static int
2306 transport_generic_get_mem(struct se_cmd *cmd)
2307 {
2308 	u32 length = cmd->data_length;
2309 	unsigned int nents;
2310 	struct page *page;
2311 	gfp_t zero_flag;
2312 	int i = 0;
2313 
2314 	nents = DIV_ROUND_UP(length, PAGE_SIZE);
2315 	cmd->t_data_sg = kmalloc(sizeof(struct scatterlist) * nents, GFP_KERNEL);
2316 	if (!cmd->t_data_sg)
2317 		return -ENOMEM;
2318 
2319 	cmd->t_data_nents = nents;
2320 	sg_init_table(cmd->t_data_sg, nents);
2321 
2322 	zero_flag = cmd->se_cmd_flags & SCF_SCSI_DATA_CDB ? 0 : __GFP_ZERO;
2323 
2324 	while (length) {
2325 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2326 		page = alloc_page(GFP_KERNEL | zero_flag);
2327 		if (!page)
2328 			goto out;
2329 
2330 		sg_set_page(&cmd->t_data_sg[i], page, page_len, 0);
2331 		length -= page_len;
2332 		i++;
2333 	}
2334 	return 0;
2335 
2336 out:
2337 	while (i > 0) {
2338 		i--;
2339 		__free_page(sg_page(&cmd->t_data_sg[i]));
2340 	}
2341 	kfree(cmd->t_data_sg);
2342 	cmd->t_data_sg = NULL;
2343 	return -ENOMEM;
2344 }
2345 
2346 /*
2347  * Allocate any required resources to execute the command.  For writes we
2348  * might not have the payload yet, so notify the fabric via a call to
2349  * ->write_pending instead. Otherwise place it on the execution queue.
2350  */
2351 int transport_generic_new_cmd(struct se_cmd *cmd)
2352 {
2353 	int ret = 0;
2354 
2355 	/*
2356 	 * Determine is the TCM fabric module has already allocated physical
2357 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2358 	 * beforehand.
2359 	 */
2360 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2361 	    cmd->data_length) {
2362 		ret = transport_generic_get_mem(cmd);
2363 		if (ret < 0)
2364 			goto out_fail;
2365 	}
2366 
2367 	atomic_inc(&cmd->t_fe_count);
2368 
2369 	/*
2370 	 * If this command is not a write we can execute it right here,
2371 	 * for write buffers we need to notify the fabric driver first
2372 	 * and let it call back once the write buffers are ready.
2373 	 */
2374 	target_add_to_state_list(cmd);
2375 	if (cmd->data_direction != DMA_TO_DEVICE) {
2376 		target_execute_cmd(cmd);
2377 		return 0;
2378 	}
2379 
2380 	spin_lock_irq(&cmd->t_state_lock);
2381 	cmd->t_state = TRANSPORT_WRITE_PENDING;
2382 	spin_unlock_irq(&cmd->t_state_lock);
2383 
2384 	transport_cmd_check_stop(cmd, false);
2385 
2386 	ret = cmd->se_tfo->write_pending(cmd);
2387 	if (ret == -EAGAIN || ret == -ENOMEM)
2388 		goto queue_full;
2389 
2390 	if (ret < 0)
2391 		return ret;
2392 	return 1;
2393 
2394 out_fail:
2395 	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
2396 	cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2397 	return -EINVAL;
2398 queue_full:
2399 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2400 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2401 	transport_handle_queue_full(cmd, cmd->se_dev);
2402 	return 0;
2403 }
2404 EXPORT_SYMBOL(transport_generic_new_cmd);
2405 
2406 static void transport_write_pending_qf(struct se_cmd *cmd)
2407 {
2408 	int ret;
2409 
2410 	ret = cmd->se_tfo->write_pending(cmd);
2411 	if (ret == -EAGAIN || ret == -ENOMEM) {
2412 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2413 			 cmd);
2414 		transport_handle_queue_full(cmd, cmd->se_dev);
2415 	}
2416 }
2417 
2418 void transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2419 {
2420 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2421 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2422 			 transport_wait_for_tasks(cmd);
2423 
2424 		transport_release_cmd(cmd);
2425 	} else {
2426 		if (wait_for_tasks)
2427 			transport_wait_for_tasks(cmd);
2428 
2429 		core_dec_lacl_count(cmd->se_sess->se_node_acl, cmd);
2430 
2431 		if (cmd->se_lun)
2432 			transport_lun_remove_cmd(cmd);
2433 
2434 		transport_put_cmd(cmd);
2435 	}
2436 }
2437 EXPORT_SYMBOL(transport_generic_free_cmd);
2438 
2439 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2440  * @se_sess:	session to reference
2441  * @se_cmd:	command descriptor to add
2442  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2443  */
2444 static int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2445 			       bool ack_kref)
2446 {
2447 	unsigned long flags;
2448 	int ret = 0;
2449 
2450 	kref_init(&se_cmd->cmd_kref);
2451 	/*
2452 	 * Add a second kref if the fabric caller is expecting to handle
2453 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2454 	 * invocations before se_cmd descriptor release.
2455 	 */
2456 	if (ack_kref == true) {
2457 		kref_get(&se_cmd->cmd_kref);
2458 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2459 	}
2460 
2461 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2462 	if (se_sess->sess_tearing_down) {
2463 		ret = -ESHUTDOWN;
2464 		goto out;
2465 	}
2466 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2467 	se_cmd->check_release = 1;
2468 
2469 out:
2470 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2471 	return ret;
2472 }
2473 
2474 static void target_release_cmd_kref(struct kref *kref)
2475 {
2476 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2477 	struct se_session *se_sess = se_cmd->se_sess;
2478 	unsigned long flags;
2479 
2480 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2481 	if (list_empty(&se_cmd->se_cmd_list)) {
2482 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2483 		se_cmd->se_tfo->release_cmd(se_cmd);
2484 		return;
2485 	}
2486 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2487 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2488 		complete(&se_cmd->cmd_wait_comp);
2489 		return;
2490 	}
2491 	list_del(&se_cmd->se_cmd_list);
2492 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2493 
2494 	se_cmd->se_tfo->release_cmd(se_cmd);
2495 }
2496 
2497 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2498  * @se_sess:	session to reference
2499  * @se_cmd:	command descriptor to drop
2500  */
2501 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2502 {
2503 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2504 }
2505 EXPORT_SYMBOL(target_put_sess_cmd);
2506 
2507 /* target_sess_cmd_list_set_waiting - Flag all commands in
2508  *         sess_cmd_list to complete cmd_wait_comp.  Set
2509  *         sess_tearing_down so no more commands are queued.
2510  * @se_sess:	session to flag
2511  */
2512 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2513 {
2514 	struct se_cmd *se_cmd;
2515 	unsigned long flags;
2516 
2517 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2518 
2519 	WARN_ON(se_sess->sess_tearing_down);
2520 	se_sess->sess_tearing_down = 1;
2521 
2522 	list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list)
2523 		se_cmd->cmd_wait_set = 1;
2524 
2525 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2526 }
2527 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2528 
2529 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2530  * @se_sess:    session to wait for active I/O
2531  * @wait_for_tasks:	Make extra transport_wait_for_tasks call
2532  */
2533 void target_wait_for_sess_cmds(
2534 	struct se_session *se_sess,
2535 	int wait_for_tasks)
2536 {
2537 	struct se_cmd *se_cmd, *tmp_cmd;
2538 	bool rc = false;
2539 
2540 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2541 				&se_sess->sess_cmd_list, se_cmd_list) {
2542 		list_del(&se_cmd->se_cmd_list);
2543 
2544 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2545 			" %d\n", se_cmd, se_cmd->t_state,
2546 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2547 
2548 		if (wait_for_tasks) {
2549 			pr_debug("Calling transport_wait_for_tasks se_cmd: %p t_state: %d,"
2550 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2551 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2552 
2553 			rc = transport_wait_for_tasks(se_cmd);
2554 
2555 			pr_debug("After transport_wait_for_tasks se_cmd: %p t_state: %d,"
2556 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2557 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2558 		}
2559 
2560 		if (!rc) {
2561 			wait_for_completion(&se_cmd->cmd_wait_comp);
2562 			pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2563 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2564 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2565 		}
2566 
2567 		se_cmd->se_tfo->release_cmd(se_cmd);
2568 	}
2569 }
2570 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2571 
2572 /*	transport_lun_wait_for_tasks():
2573  *
2574  *	Called from ConfigFS context to stop the passed struct se_cmd to allow
2575  *	an struct se_lun to be successfully shutdown.
2576  */
2577 static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
2578 {
2579 	unsigned long flags;
2580 	int ret = 0;
2581 
2582 	/*
2583 	 * If the frontend has already requested this struct se_cmd to
2584 	 * be stopped, we can safely ignore this struct se_cmd.
2585 	 */
2586 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2587 	if (cmd->transport_state & CMD_T_STOP) {
2588 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2589 
2590 		pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
2591 			 cmd->se_tfo->get_task_tag(cmd));
2592 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2593 		transport_cmd_check_stop(cmd, false);
2594 		return -EPERM;
2595 	}
2596 	cmd->transport_state |= CMD_T_LUN_FE_STOP;
2597 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2598 
2599 	// XXX: audit task_flags checks.
2600 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2601 	if ((cmd->transport_state & CMD_T_BUSY) &&
2602 	    (cmd->transport_state & CMD_T_SENT)) {
2603 		if (!target_stop_cmd(cmd, &flags))
2604 			ret++;
2605 	}
2606 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2607 
2608 	pr_debug("ConfigFS: cmd: %p stop tasks ret:"
2609 			" %d\n", cmd, ret);
2610 	if (!ret) {
2611 		pr_debug("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
2612 				cmd->se_tfo->get_task_tag(cmd));
2613 		wait_for_completion(&cmd->transport_lun_stop_comp);
2614 		pr_debug("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
2615 				cmd->se_tfo->get_task_tag(cmd));
2616 	}
2617 
2618 	return 0;
2619 }
2620 
2621 static void __transport_clear_lun_from_sessions(struct se_lun *lun)
2622 {
2623 	struct se_cmd *cmd = NULL;
2624 	unsigned long lun_flags, cmd_flags;
2625 	/*
2626 	 * Do exception processing and return CHECK_CONDITION status to the
2627 	 * Initiator Port.
2628 	 */
2629 	spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2630 	while (!list_empty(&lun->lun_cmd_list)) {
2631 		cmd = list_first_entry(&lun->lun_cmd_list,
2632 		       struct se_cmd, se_lun_node);
2633 		list_del_init(&cmd->se_lun_node);
2634 
2635 		spin_lock(&cmd->t_state_lock);
2636 		pr_debug("SE_LUN[%d] - Setting cmd->transport"
2637 			"_lun_stop for  ITT: 0x%08x\n",
2638 			cmd->se_lun->unpacked_lun,
2639 			cmd->se_tfo->get_task_tag(cmd));
2640 		cmd->transport_state |= CMD_T_LUN_STOP;
2641 		spin_unlock(&cmd->t_state_lock);
2642 
2643 		spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2644 
2645 		if (!cmd->se_lun) {
2646 			pr_err("ITT: 0x%08x, [i,t]_state: %u/%u\n",
2647 				cmd->se_tfo->get_task_tag(cmd),
2648 				cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2649 			BUG();
2650 		}
2651 		/*
2652 		 * If the Storage engine still owns the iscsi_cmd_t, determine
2653 		 * and/or stop its context.
2654 		 */
2655 		pr_debug("SE_LUN[%d] - ITT: 0x%08x before transport"
2656 			"_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
2657 			cmd->se_tfo->get_task_tag(cmd));
2658 
2659 		if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
2660 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2661 			continue;
2662 		}
2663 
2664 		pr_debug("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
2665 			"_wait_for_tasks(): SUCCESS\n",
2666 			cmd->se_lun->unpacked_lun,
2667 			cmd->se_tfo->get_task_tag(cmd));
2668 
2669 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2670 		if (!(cmd->transport_state & CMD_T_DEV_ACTIVE)) {
2671 			spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2672 			goto check_cond;
2673 		}
2674 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2675 		target_remove_from_state_list(cmd);
2676 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2677 
2678 		/*
2679 		 * The Storage engine stopped this struct se_cmd before it was
2680 		 * send to the fabric frontend for delivery back to the
2681 		 * Initiator Node.  Return this SCSI CDB back with an
2682 		 * CHECK_CONDITION status.
2683 		 */
2684 check_cond:
2685 		transport_send_check_condition_and_sense(cmd,
2686 				TCM_NON_EXISTENT_LUN, 0);
2687 		/*
2688 		 *  If the fabric frontend is waiting for this iscsi_cmd_t to
2689 		 * be released, notify the waiting thread now that LU has
2690 		 * finished accessing it.
2691 		 */
2692 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2693 		if (cmd->transport_state & CMD_T_LUN_FE_STOP) {
2694 			pr_debug("SE_LUN[%d] - Detected FE stop for"
2695 				" struct se_cmd: %p ITT: 0x%08x\n",
2696 				lun->unpacked_lun,
2697 				cmd, cmd->se_tfo->get_task_tag(cmd));
2698 
2699 			spin_unlock_irqrestore(&cmd->t_state_lock,
2700 					cmd_flags);
2701 			transport_cmd_check_stop(cmd, false);
2702 			complete(&cmd->transport_lun_fe_stop_comp);
2703 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2704 			continue;
2705 		}
2706 		pr_debug("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
2707 			lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));
2708 
2709 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2710 		spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2711 	}
2712 	spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2713 }
2714 
2715 static int transport_clear_lun_thread(void *p)
2716 {
2717 	struct se_lun *lun = p;
2718 
2719 	__transport_clear_lun_from_sessions(lun);
2720 	complete(&lun->lun_shutdown_comp);
2721 
2722 	return 0;
2723 }
2724 
2725 int transport_clear_lun_from_sessions(struct se_lun *lun)
2726 {
2727 	struct task_struct *kt;
2728 
2729 	kt = kthread_run(transport_clear_lun_thread, lun,
2730 			"tcm_cl_%u", lun->unpacked_lun);
2731 	if (IS_ERR(kt)) {
2732 		pr_err("Unable to start clear_lun thread\n");
2733 		return PTR_ERR(kt);
2734 	}
2735 	wait_for_completion(&lun->lun_shutdown_comp);
2736 
2737 	return 0;
2738 }
2739 
2740 /**
2741  * transport_wait_for_tasks - wait for completion to occur
2742  * @cmd:	command to wait
2743  *
2744  * Called from frontend fabric context to wait for storage engine
2745  * to pause and/or release frontend generated struct se_cmd.
2746  */
2747 bool transport_wait_for_tasks(struct se_cmd *cmd)
2748 {
2749 	unsigned long flags;
2750 
2751 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2752 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2753 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2754 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2755 		return false;
2756 	}
2757 
2758 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2759 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2760 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2761 		return false;
2762 	}
2763 	/*
2764 	 * If we are already stopped due to an external event (ie: LUN shutdown)
2765 	 * sleep until the connection can have the passed struct se_cmd back.
2766 	 * The cmd->transport_lun_stopped_sem will be upped by
2767 	 * transport_clear_lun_from_sessions() once the ConfigFS context caller
2768 	 * has completed its operation on the struct se_cmd.
2769 	 */
2770 	if (cmd->transport_state & CMD_T_LUN_STOP) {
2771 		pr_debug("wait_for_tasks: Stopping"
2772 			" wait_for_completion(&cmd->t_tasktransport_lun_fe"
2773 			"_stop_comp); for ITT: 0x%08x\n",
2774 			cmd->se_tfo->get_task_tag(cmd));
2775 		/*
2776 		 * There is a special case for WRITES where a FE exception +
2777 		 * LUN shutdown means ConfigFS context is still sleeping on
2778 		 * transport_lun_stop_comp in transport_lun_wait_for_tasks().
2779 		 * We go ahead and up transport_lun_stop_comp just to be sure
2780 		 * here.
2781 		 */
2782 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2783 		complete(&cmd->transport_lun_stop_comp);
2784 		wait_for_completion(&cmd->transport_lun_fe_stop_comp);
2785 		spin_lock_irqsave(&cmd->t_state_lock, flags);
2786 
2787 		target_remove_from_state_list(cmd);
2788 		/*
2789 		 * At this point, the frontend who was the originator of this
2790 		 * struct se_cmd, now owns the structure and can be released through
2791 		 * normal means below.
2792 		 */
2793 		pr_debug("wait_for_tasks: Stopped"
2794 			" wait_for_completion(&cmd->t_tasktransport_lun_fe_"
2795 			"stop_comp); for ITT: 0x%08x\n",
2796 			cmd->se_tfo->get_task_tag(cmd));
2797 
2798 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2799 	}
2800 
2801 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2802 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2803 		return false;
2804 	}
2805 
2806 	cmd->transport_state |= CMD_T_STOP;
2807 
2808 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2809 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2810 		cmd, cmd->se_tfo->get_task_tag(cmd),
2811 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2812 
2813 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2814 
2815 	wait_for_completion(&cmd->t_transport_stop_comp);
2816 
2817 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2818 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2819 
2820 	pr_debug("wait_for_tasks: Stopped wait_for_completion("
2821 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2822 		cmd->se_tfo->get_task_tag(cmd));
2823 
2824 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2825 
2826 	return true;
2827 }
2828 EXPORT_SYMBOL(transport_wait_for_tasks);
2829 
2830 static int transport_get_sense_codes(
2831 	struct se_cmd *cmd,
2832 	u8 *asc,
2833 	u8 *ascq)
2834 {
2835 	*asc = cmd->scsi_asc;
2836 	*ascq = cmd->scsi_ascq;
2837 
2838 	return 0;
2839 }
2840 
2841 static int transport_set_sense_codes(
2842 	struct se_cmd *cmd,
2843 	u8 asc,
2844 	u8 ascq)
2845 {
2846 	cmd->scsi_asc = asc;
2847 	cmd->scsi_ascq = ascq;
2848 
2849 	return 0;
2850 }
2851 
2852 int transport_send_check_condition_and_sense(
2853 	struct se_cmd *cmd,
2854 	u8 reason,
2855 	int from_transport)
2856 {
2857 	unsigned char *buffer = cmd->sense_buffer;
2858 	unsigned long flags;
2859 	u8 asc = 0, ascq = 0;
2860 
2861 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2862 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2863 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2864 		return 0;
2865 	}
2866 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2867 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2868 
2869 	if (!reason && from_transport)
2870 		goto after_reason;
2871 
2872 	if (!from_transport)
2873 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2874 
2875 	/*
2876 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2877 	 * SENSE KEY values from include/scsi/scsi.h
2878 	 */
2879 	switch (reason) {
2880 	case TCM_NON_EXISTENT_LUN:
2881 		/* CURRENT ERROR */
2882 		buffer[0] = 0x70;
2883 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2884 		/* ILLEGAL REQUEST */
2885 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2886 		/* LOGICAL UNIT NOT SUPPORTED */
2887 		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2888 		break;
2889 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2890 	case TCM_SECTOR_COUNT_TOO_MANY:
2891 		/* CURRENT ERROR */
2892 		buffer[0] = 0x70;
2893 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2894 		/* ILLEGAL REQUEST */
2895 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2896 		/* INVALID COMMAND OPERATION CODE */
2897 		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2898 		break;
2899 	case TCM_UNKNOWN_MODE_PAGE:
2900 		/* CURRENT ERROR */
2901 		buffer[0] = 0x70;
2902 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2903 		/* ILLEGAL REQUEST */
2904 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2905 		/* INVALID FIELD IN CDB */
2906 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2907 		break;
2908 	case TCM_CHECK_CONDITION_ABORT_CMD:
2909 		/* CURRENT ERROR */
2910 		buffer[0] = 0x70;
2911 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2912 		/* ABORTED COMMAND */
2913 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2914 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2915 		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2916 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2917 		break;
2918 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2919 		/* CURRENT ERROR */
2920 		buffer[0] = 0x70;
2921 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2922 		/* ABORTED COMMAND */
2923 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2924 		/* WRITE ERROR */
2925 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2926 		/* NOT ENOUGH UNSOLICITED DATA */
2927 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2928 		break;
2929 	case TCM_INVALID_CDB_FIELD:
2930 		/* CURRENT ERROR */
2931 		buffer[0] = 0x70;
2932 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2933 		/* ILLEGAL REQUEST */
2934 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2935 		/* INVALID FIELD IN CDB */
2936 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2937 		break;
2938 	case TCM_INVALID_PARAMETER_LIST:
2939 		/* CURRENT ERROR */
2940 		buffer[0] = 0x70;
2941 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2942 		/* ILLEGAL REQUEST */
2943 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2944 		/* INVALID FIELD IN PARAMETER LIST */
2945 		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2946 		break;
2947 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2948 		/* CURRENT ERROR */
2949 		buffer[0] = 0x70;
2950 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2951 		/* ABORTED COMMAND */
2952 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2953 		/* WRITE ERROR */
2954 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2955 		/* UNEXPECTED_UNSOLICITED_DATA */
2956 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2957 		break;
2958 	case TCM_SERVICE_CRC_ERROR:
2959 		/* CURRENT ERROR */
2960 		buffer[0] = 0x70;
2961 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2962 		/* ABORTED COMMAND */
2963 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2964 		/* PROTOCOL SERVICE CRC ERROR */
2965 		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2966 		/* N/A */
2967 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2968 		break;
2969 	case TCM_SNACK_REJECTED:
2970 		/* CURRENT ERROR */
2971 		buffer[0] = 0x70;
2972 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2973 		/* ABORTED COMMAND */
2974 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2975 		/* READ ERROR */
2976 		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2977 		/* FAILED RETRANSMISSION REQUEST */
2978 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2979 		break;
2980 	case TCM_WRITE_PROTECTED:
2981 		/* CURRENT ERROR */
2982 		buffer[0] = 0x70;
2983 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2984 		/* DATA PROTECT */
2985 		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2986 		/* WRITE PROTECTED */
2987 		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2988 		break;
2989 	case TCM_ADDRESS_OUT_OF_RANGE:
2990 		/* CURRENT ERROR */
2991 		buffer[0] = 0x70;
2992 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2993 		/* ILLEGAL REQUEST */
2994 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2995 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2996 		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2997 		break;
2998 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2999 		/* CURRENT ERROR */
3000 		buffer[0] = 0x70;
3001 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
3002 		/* UNIT ATTENTION */
3003 		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
3004 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
3005 		buffer[SPC_ASC_KEY_OFFSET] = asc;
3006 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
3007 		break;
3008 	case TCM_CHECK_CONDITION_NOT_READY:
3009 		/* CURRENT ERROR */
3010 		buffer[0] = 0x70;
3011 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
3012 		/* Not Ready */
3013 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
3014 		transport_get_sense_codes(cmd, &asc, &ascq);
3015 		buffer[SPC_ASC_KEY_OFFSET] = asc;
3016 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
3017 		break;
3018 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
3019 	default:
3020 		/* CURRENT ERROR */
3021 		buffer[0] = 0x70;
3022 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
3023 		/* ILLEGAL REQUEST */
3024 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
3025 		/* LOGICAL UNIT COMMUNICATION FAILURE */
3026 		buffer[SPC_ASC_KEY_OFFSET] = 0x80;
3027 		break;
3028 	}
3029 	/*
3030 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
3031 	 */
3032 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3033 	/*
3034 	 * Automatically padded, this value is encoded in the fabric's
3035 	 * data_length response PDU containing the SCSI defined sense data.
3036 	 */
3037 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3038 
3039 after_reason:
3040 	return cmd->se_tfo->queue_status(cmd);
3041 }
3042 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3043 
3044 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3045 {
3046 	int ret = 0;
3047 
3048 	if (cmd->transport_state & CMD_T_ABORTED) {
3049 		if (!send_status ||
3050 		     (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
3051 			return 1;
3052 
3053 		pr_debug("Sending delayed SAM_STAT_TASK_ABORTED"
3054 			" status for CDB: 0x%02x ITT: 0x%08x\n",
3055 			cmd->t_task_cdb[0],
3056 			cmd->se_tfo->get_task_tag(cmd));
3057 
3058 		cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
3059 		cmd->se_tfo->queue_status(cmd);
3060 		ret = 1;
3061 	}
3062 	return ret;
3063 }
3064 EXPORT_SYMBOL(transport_check_aborted_status);
3065 
3066 void transport_send_task_abort(struct se_cmd *cmd)
3067 {
3068 	unsigned long flags;
3069 
3070 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3071 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3072 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3073 		return;
3074 	}
3075 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3076 
3077 	/*
3078 	 * If there are still expected incoming fabric WRITEs, we wait
3079 	 * until until they have completed before sending a TASK_ABORTED
3080 	 * response.  This response with TASK_ABORTED status will be
3081 	 * queued back to fabric module by transport_check_aborted_status().
3082 	 */
3083 	if (cmd->data_direction == DMA_TO_DEVICE) {
3084 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3085 			cmd->transport_state |= CMD_T_ABORTED;
3086 			smp_mb__after_atomic_inc();
3087 		}
3088 	}
3089 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3090 
3091 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
3092 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
3093 		cmd->se_tfo->get_task_tag(cmd));
3094 
3095 	cmd->se_tfo->queue_status(cmd);
3096 }
3097 
3098 static void target_tmr_work(struct work_struct *work)
3099 {
3100 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3101 	struct se_device *dev = cmd->se_dev;
3102 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3103 	int ret;
3104 
3105 	switch (tmr->function) {
3106 	case TMR_ABORT_TASK:
3107 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3108 		break;
3109 	case TMR_ABORT_TASK_SET:
3110 	case TMR_CLEAR_ACA:
3111 	case TMR_CLEAR_TASK_SET:
3112 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3113 		break;
3114 	case TMR_LUN_RESET:
3115 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3116 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3117 					 TMR_FUNCTION_REJECTED;
3118 		break;
3119 	case TMR_TARGET_WARM_RESET:
3120 		tmr->response = TMR_FUNCTION_REJECTED;
3121 		break;
3122 	case TMR_TARGET_COLD_RESET:
3123 		tmr->response = TMR_FUNCTION_REJECTED;
3124 		break;
3125 	default:
3126 		pr_err("Uknown TMR function: 0x%02x.\n",
3127 				tmr->function);
3128 		tmr->response = TMR_FUNCTION_REJECTED;
3129 		break;
3130 	}
3131 
3132 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3133 	cmd->se_tfo->queue_tm_rsp(cmd);
3134 
3135 	transport_cmd_check_stop_to_fabric(cmd);
3136 }
3137 
3138 int transport_generic_handle_tmr(
3139 	struct se_cmd *cmd)
3140 {
3141 	INIT_WORK(&cmd->work, target_tmr_work);
3142 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3143 	return 0;
3144 }
3145 EXPORT_SYMBOL(transport_generic_handle_tmr);
3146