xref: /openbmc/linux/drivers/target/target_core_transport.c (revision 2e7c04aec86758e0adfcad4a24c86593b45807a3)
1 /*******************************************************************************
2  * Filename:  target_core_transport.c
3  *
4  * This file contains the Generic Target Engine Core.
5  *
6  * (c) Copyright 2002-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/net.h>
27 #include <linux/delay.h>
28 #include <linux/string.h>
29 #include <linux/timer.h>
30 #include <linux/slab.h>
31 #include <linux/spinlock.h>
32 #include <linux/kthread.h>
33 #include <linux/in.h>
34 #include <linux/cdrom.h>
35 #include <linux/module.h>
36 #include <linux/ratelimit.h>
37 #include <linux/vmalloc.h>
38 #include <asm/unaligned.h>
39 #include <net/sock.h>
40 #include <net/tcp.h>
41 #include <scsi/scsi_proto.h>
42 #include <scsi/scsi_common.h>
43 
44 #include <target/target_core_base.h>
45 #include <target/target_core_backend.h>
46 #include <target/target_core_fabric.h>
47 
48 #include "target_core_internal.h"
49 #include "target_core_alua.h"
50 #include "target_core_pr.h"
51 #include "target_core_ua.h"
52 
53 #define CREATE_TRACE_POINTS
54 #include <trace/events/target.h>
55 
56 static struct workqueue_struct *target_completion_wq;
57 static struct kmem_cache *se_sess_cache;
58 struct kmem_cache *se_ua_cache;
59 struct kmem_cache *t10_pr_reg_cache;
60 struct kmem_cache *t10_alua_lu_gp_cache;
61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
63 struct kmem_cache *t10_alua_lba_map_cache;
64 struct kmem_cache *t10_alua_lba_map_mem_cache;
65 
66 static void transport_complete_task_attr(struct se_cmd *cmd);
67 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
68 static void transport_handle_queue_full(struct se_cmd *cmd,
69 		struct se_device *dev, int err, bool write_pending);
70 static void target_complete_ok_work(struct work_struct *work);
71 
72 int init_se_kmem_caches(void)
73 {
74 	se_sess_cache = kmem_cache_create("se_sess_cache",
75 			sizeof(struct se_session), __alignof__(struct se_session),
76 			0, NULL);
77 	if (!se_sess_cache) {
78 		pr_err("kmem_cache_create() for struct se_session"
79 				" failed\n");
80 		goto out;
81 	}
82 	se_ua_cache = kmem_cache_create("se_ua_cache",
83 			sizeof(struct se_ua), __alignof__(struct se_ua),
84 			0, NULL);
85 	if (!se_ua_cache) {
86 		pr_err("kmem_cache_create() for struct se_ua failed\n");
87 		goto out_free_sess_cache;
88 	}
89 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
90 			sizeof(struct t10_pr_registration),
91 			__alignof__(struct t10_pr_registration), 0, NULL);
92 	if (!t10_pr_reg_cache) {
93 		pr_err("kmem_cache_create() for struct t10_pr_registration"
94 				" failed\n");
95 		goto out_free_ua_cache;
96 	}
97 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
98 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
99 			0, NULL);
100 	if (!t10_alua_lu_gp_cache) {
101 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
102 				" failed\n");
103 		goto out_free_pr_reg_cache;
104 	}
105 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
106 			sizeof(struct t10_alua_lu_gp_member),
107 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
108 	if (!t10_alua_lu_gp_mem_cache) {
109 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
110 				"cache failed\n");
111 		goto out_free_lu_gp_cache;
112 	}
113 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
114 			sizeof(struct t10_alua_tg_pt_gp),
115 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
116 	if (!t10_alua_tg_pt_gp_cache) {
117 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
118 				"cache failed\n");
119 		goto out_free_lu_gp_mem_cache;
120 	}
121 	t10_alua_lba_map_cache = kmem_cache_create(
122 			"t10_alua_lba_map_cache",
123 			sizeof(struct t10_alua_lba_map),
124 			__alignof__(struct t10_alua_lba_map), 0, NULL);
125 	if (!t10_alua_lba_map_cache) {
126 		pr_err("kmem_cache_create() for t10_alua_lba_map_"
127 				"cache failed\n");
128 		goto out_free_tg_pt_gp_cache;
129 	}
130 	t10_alua_lba_map_mem_cache = kmem_cache_create(
131 			"t10_alua_lba_map_mem_cache",
132 			sizeof(struct t10_alua_lba_map_member),
133 			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
134 	if (!t10_alua_lba_map_mem_cache) {
135 		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
136 				"cache failed\n");
137 		goto out_free_lba_map_cache;
138 	}
139 
140 	target_completion_wq = alloc_workqueue("target_completion",
141 					       WQ_MEM_RECLAIM, 0);
142 	if (!target_completion_wq)
143 		goto out_free_lba_map_mem_cache;
144 
145 	return 0;
146 
147 out_free_lba_map_mem_cache:
148 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
149 out_free_lba_map_cache:
150 	kmem_cache_destroy(t10_alua_lba_map_cache);
151 out_free_tg_pt_gp_cache:
152 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
153 out_free_lu_gp_mem_cache:
154 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
155 out_free_lu_gp_cache:
156 	kmem_cache_destroy(t10_alua_lu_gp_cache);
157 out_free_pr_reg_cache:
158 	kmem_cache_destroy(t10_pr_reg_cache);
159 out_free_ua_cache:
160 	kmem_cache_destroy(se_ua_cache);
161 out_free_sess_cache:
162 	kmem_cache_destroy(se_sess_cache);
163 out:
164 	return -ENOMEM;
165 }
166 
167 void release_se_kmem_caches(void)
168 {
169 	destroy_workqueue(target_completion_wq);
170 	kmem_cache_destroy(se_sess_cache);
171 	kmem_cache_destroy(se_ua_cache);
172 	kmem_cache_destroy(t10_pr_reg_cache);
173 	kmem_cache_destroy(t10_alua_lu_gp_cache);
174 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
175 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
176 	kmem_cache_destroy(t10_alua_lba_map_cache);
177 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
178 }
179 
180 /* This code ensures unique mib indexes are handed out. */
181 static DEFINE_SPINLOCK(scsi_mib_index_lock);
182 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
183 
184 /*
185  * Allocate a new row index for the entry type specified
186  */
187 u32 scsi_get_new_index(scsi_index_t type)
188 {
189 	u32 new_index;
190 
191 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
192 
193 	spin_lock(&scsi_mib_index_lock);
194 	new_index = ++scsi_mib_index[type];
195 	spin_unlock(&scsi_mib_index_lock);
196 
197 	return new_index;
198 }
199 
200 void transport_subsystem_check_init(void)
201 {
202 	int ret;
203 	static int sub_api_initialized;
204 
205 	if (sub_api_initialized)
206 		return;
207 
208 	ret = request_module("target_core_iblock");
209 	if (ret != 0)
210 		pr_err("Unable to load target_core_iblock\n");
211 
212 	ret = request_module("target_core_file");
213 	if (ret != 0)
214 		pr_err("Unable to load target_core_file\n");
215 
216 	ret = request_module("target_core_pscsi");
217 	if (ret != 0)
218 		pr_err("Unable to load target_core_pscsi\n");
219 
220 	ret = request_module("target_core_user");
221 	if (ret != 0)
222 		pr_err("Unable to load target_core_user\n");
223 
224 	sub_api_initialized = 1;
225 }
226 
227 /**
228  * transport_init_session - initialize a session object
229  * @se_sess: Session object pointer.
230  *
231  * The caller must have zero-initialized @se_sess before calling this function.
232  */
233 void transport_init_session(struct se_session *se_sess)
234 {
235 	INIT_LIST_HEAD(&se_sess->sess_list);
236 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
237 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
238 	spin_lock_init(&se_sess->sess_cmd_lock);
239 	init_waitqueue_head(&se_sess->cmd_list_wq);
240 }
241 EXPORT_SYMBOL(transport_init_session);
242 
243 /**
244  * transport_alloc_session - allocate a session object and initialize it
245  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
246  */
247 struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
248 {
249 	struct se_session *se_sess;
250 
251 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
252 	if (!se_sess) {
253 		pr_err("Unable to allocate struct se_session from"
254 				" se_sess_cache\n");
255 		return ERR_PTR(-ENOMEM);
256 	}
257 	transport_init_session(se_sess);
258 	se_sess->sup_prot_ops = sup_prot_ops;
259 
260 	return se_sess;
261 }
262 EXPORT_SYMBOL(transport_alloc_session);
263 
264 /**
265  * transport_alloc_session_tags - allocate target driver private data
266  * @se_sess:  Session pointer.
267  * @tag_num:  Maximum number of in-flight commands between initiator and target.
268  * @tag_size: Size in bytes of the private data a target driver associates with
269  *	      each command.
270  */
271 int transport_alloc_session_tags(struct se_session *se_sess,
272 			         unsigned int tag_num, unsigned int tag_size)
273 {
274 	int rc;
275 
276 	se_sess->sess_cmd_map = kcalloc(tag_size, tag_num,
277 					GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);
278 	if (!se_sess->sess_cmd_map) {
279 		se_sess->sess_cmd_map = vzalloc(array_size(tag_size, tag_num));
280 		if (!se_sess->sess_cmd_map) {
281 			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
282 			return -ENOMEM;
283 		}
284 	}
285 
286 	rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
287 			false, GFP_KERNEL, NUMA_NO_NODE);
288 	if (rc < 0) {
289 		pr_err("Unable to init se_sess->sess_tag_pool,"
290 			" tag_num: %u\n", tag_num);
291 		kvfree(se_sess->sess_cmd_map);
292 		se_sess->sess_cmd_map = NULL;
293 		return -ENOMEM;
294 	}
295 
296 	return 0;
297 }
298 EXPORT_SYMBOL(transport_alloc_session_tags);
299 
300 /**
301  * transport_init_session_tags - allocate a session and target driver private data
302  * @tag_num:  Maximum number of in-flight commands between initiator and target.
303  * @tag_size: Size in bytes of the private data a target driver associates with
304  *	      each command.
305  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
306  */
307 static struct se_session *
308 transport_init_session_tags(unsigned int tag_num, unsigned int tag_size,
309 			    enum target_prot_op sup_prot_ops)
310 {
311 	struct se_session *se_sess;
312 	int rc;
313 
314 	if (tag_num != 0 && !tag_size) {
315 		pr_err("init_session_tags called with percpu-ida tag_num:"
316 		       " %u, but zero tag_size\n", tag_num);
317 		return ERR_PTR(-EINVAL);
318 	}
319 	if (!tag_num && tag_size) {
320 		pr_err("init_session_tags called with percpu-ida tag_size:"
321 		       " %u, but zero tag_num\n", tag_size);
322 		return ERR_PTR(-EINVAL);
323 	}
324 
325 	se_sess = transport_alloc_session(sup_prot_ops);
326 	if (IS_ERR(se_sess))
327 		return se_sess;
328 
329 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
330 	if (rc < 0) {
331 		transport_free_session(se_sess);
332 		return ERR_PTR(-ENOMEM);
333 	}
334 
335 	return se_sess;
336 }
337 
338 /*
339  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
340  */
341 void __transport_register_session(
342 	struct se_portal_group *se_tpg,
343 	struct se_node_acl *se_nacl,
344 	struct se_session *se_sess,
345 	void *fabric_sess_ptr)
346 {
347 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
348 	unsigned char buf[PR_REG_ISID_LEN];
349 	unsigned long flags;
350 
351 	se_sess->se_tpg = se_tpg;
352 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
353 	/*
354 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
355 	 *
356 	 * Only set for struct se_session's that will actually be moving I/O.
357 	 * eg: *NOT* discovery sessions.
358 	 */
359 	if (se_nacl) {
360 		/*
361 		 *
362 		 * Determine if fabric allows for T10-PI feature bits exposed to
363 		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
364 		 *
365 		 * If so, then always save prot_type on a per se_node_acl node
366 		 * basis and re-instate the previous sess_prot_type to avoid
367 		 * disabling PI from below any previously initiator side
368 		 * registered LUNs.
369 		 */
370 		if (se_nacl->saved_prot_type)
371 			se_sess->sess_prot_type = se_nacl->saved_prot_type;
372 		else if (tfo->tpg_check_prot_fabric_only)
373 			se_sess->sess_prot_type = se_nacl->saved_prot_type =
374 					tfo->tpg_check_prot_fabric_only(se_tpg);
375 		/*
376 		 * If the fabric module supports an ISID based TransportID,
377 		 * save this value in binary from the fabric I_T Nexus now.
378 		 */
379 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
380 			memset(&buf[0], 0, PR_REG_ISID_LEN);
381 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
382 					&buf[0], PR_REG_ISID_LEN);
383 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
384 		}
385 
386 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
387 		/*
388 		 * The se_nacl->nacl_sess pointer will be set to the
389 		 * last active I_T Nexus for each struct se_node_acl.
390 		 */
391 		se_nacl->nacl_sess = se_sess;
392 
393 		list_add_tail(&se_sess->sess_acl_list,
394 			      &se_nacl->acl_sess_list);
395 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
396 	}
397 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
398 
399 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
400 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
401 }
402 EXPORT_SYMBOL(__transport_register_session);
403 
404 void transport_register_session(
405 	struct se_portal_group *se_tpg,
406 	struct se_node_acl *se_nacl,
407 	struct se_session *se_sess,
408 	void *fabric_sess_ptr)
409 {
410 	unsigned long flags;
411 
412 	spin_lock_irqsave(&se_tpg->session_lock, flags);
413 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
414 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
415 }
416 EXPORT_SYMBOL(transport_register_session);
417 
418 struct se_session *
419 target_setup_session(struct se_portal_group *tpg,
420 		     unsigned int tag_num, unsigned int tag_size,
421 		     enum target_prot_op prot_op,
422 		     const char *initiatorname, void *private,
423 		     int (*callback)(struct se_portal_group *,
424 				     struct se_session *, void *))
425 {
426 	struct se_session *sess;
427 
428 	/*
429 	 * If the fabric driver is using percpu-ida based pre allocation
430 	 * of I/O descriptor tags, go ahead and perform that setup now..
431 	 */
432 	if (tag_num != 0)
433 		sess = transport_init_session_tags(tag_num, tag_size, prot_op);
434 	else
435 		sess = transport_alloc_session(prot_op);
436 
437 	if (IS_ERR(sess))
438 		return sess;
439 
440 	sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
441 					(unsigned char *)initiatorname);
442 	if (!sess->se_node_acl) {
443 		transport_free_session(sess);
444 		return ERR_PTR(-EACCES);
445 	}
446 	/*
447 	 * Go ahead and perform any remaining fabric setup that is
448 	 * required before transport_register_session().
449 	 */
450 	if (callback != NULL) {
451 		int rc = callback(tpg, sess, private);
452 		if (rc) {
453 			transport_free_session(sess);
454 			return ERR_PTR(rc);
455 		}
456 	}
457 
458 	transport_register_session(tpg, sess->se_node_acl, sess, private);
459 	return sess;
460 }
461 EXPORT_SYMBOL(target_setup_session);
462 
463 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
464 {
465 	struct se_session *se_sess;
466 	ssize_t len = 0;
467 
468 	spin_lock_bh(&se_tpg->session_lock);
469 	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
470 		if (!se_sess->se_node_acl)
471 			continue;
472 		if (!se_sess->se_node_acl->dynamic_node_acl)
473 			continue;
474 		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
475 			break;
476 
477 		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
478 				se_sess->se_node_acl->initiatorname);
479 		len += 1; /* Include NULL terminator */
480 	}
481 	spin_unlock_bh(&se_tpg->session_lock);
482 
483 	return len;
484 }
485 EXPORT_SYMBOL(target_show_dynamic_sessions);
486 
487 static void target_complete_nacl(struct kref *kref)
488 {
489 	struct se_node_acl *nacl = container_of(kref,
490 				struct se_node_acl, acl_kref);
491 	struct se_portal_group *se_tpg = nacl->se_tpg;
492 
493 	if (!nacl->dynamic_stop) {
494 		complete(&nacl->acl_free_comp);
495 		return;
496 	}
497 
498 	mutex_lock(&se_tpg->acl_node_mutex);
499 	list_del_init(&nacl->acl_list);
500 	mutex_unlock(&se_tpg->acl_node_mutex);
501 
502 	core_tpg_wait_for_nacl_pr_ref(nacl);
503 	core_free_device_list_for_node(nacl, se_tpg);
504 	kfree(nacl);
505 }
506 
507 void target_put_nacl(struct se_node_acl *nacl)
508 {
509 	kref_put(&nacl->acl_kref, target_complete_nacl);
510 }
511 EXPORT_SYMBOL(target_put_nacl);
512 
513 void transport_deregister_session_configfs(struct se_session *se_sess)
514 {
515 	struct se_node_acl *se_nacl;
516 	unsigned long flags;
517 	/*
518 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
519 	 */
520 	se_nacl = se_sess->se_node_acl;
521 	if (se_nacl) {
522 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
523 		if (!list_empty(&se_sess->sess_acl_list))
524 			list_del_init(&se_sess->sess_acl_list);
525 		/*
526 		 * If the session list is empty, then clear the pointer.
527 		 * Otherwise, set the struct se_session pointer from the tail
528 		 * element of the per struct se_node_acl active session list.
529 		 */
530 		if (list_empty(&se_nacl->acl_sess_list))
531 			se_nacl->nacl_sess = NULL;
532 		else {
533 			se_nacl->nacl_sess = container_of(
534 					se_nacl->acl_sess_list.prev,
535 					struct se_session, sess_acl_list);
536 		}
537 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
538 	}
539 }
540 EXPORT_SYMBOL(transport_deregister_session_configfs);
541 
542 void transport_free_session(struct se_session *se_sess)
543 {
544 	struct se_node_acl *se_nacl = se_sess->se_node_acl;
545 
546 	/*
547 	 * Drop the se_node_acl->nacl_kref obtained from within
548 	 * core_tpg_get_initiator_node_acl().
549 	 */
550 	if (se_nacl) {
551 		struct se_portal_group *se_tpg = se_nacl->se_tpg;
552 		const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
553 		unsigned long flags;
554 
555 		se_sess->se_node_acl = NULL;
556 
557 		/*
558 		 * Also determine if we need to drop the extra ->cmd_kref if
559 		 * it had been previously dynamically generated, and
560 		 * the endpoint is not caching dynamic ACLs.
561 		 */
562 		mutex_lock(&se_tpg->acl_node_mutex);
563 		if (se_nacl->dynamic_node_acl &&
564 		    !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
565 			spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
566 			if (list_empty(&se_nacl->acl_sess_list))
567 				se_nacl->dynamic_stop = true;
568 			spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
569 
570 			if (se_nacl->dynamic_stop)
571 				list_del_init(&se_nacl->acl_list);
572 		}
573 		mutex_unlock(&se_tpg->acl_node_mutex);
574 
575 		if (se_nacl->dynamic_stop)
576 			target_put_nacl(se_nacl);
577 
578 		target_put_nacl(se_nacl);
579 	}
580 	if (se_sess->sess_cmd_map) {
581 		sbitmap_queue_free(&se_sess->sess_tag_pool);
582 		kvfree(se_sess->sess_cmd_map);
583 	}
584 	kmem_cache_free(se_sess_cache, se_sess);
585 }
586 EXPORT_SYMBOL(transport_free_session);
587 
588 void transport_deregister_session(struct se_session *se_sess)
589 {
590 	struct se_portal_group *se_tpg = se_sess->se_tpg;
591 	unsigned long flags;
592 
593 	if (!se_tpg) {
594 		transport_free_session(se_sess);
595 		return;
596 	}
597 
598 	spin_lock_irqsave(&se_tpg->session_lock, flags);
599 	list_del(&se_sess->sess_list);
600 	se_sess->se_tpg = NULL;
601 	se_sess->fabric_sess_ptr = NULL;
602 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
603 
604 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
605 		se_tpg->se_tpg_tfo->get_fabric_name());
606 	/*
607 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
608 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
609 	 * removal context from within transport_free_session() code.
610 	 *
611 	 * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
612 	 * to release all remaining generate_node_acl=1 created ACL resources.
613 	 */
614 
615 	transport_free_session(se_sess);
616 }
617 EXPORT_SYMBOL(transport_deregister_session);
618 
619 void target_remove_session(struct se_session *se_sess)
620 {
621 	transport_deregister_session_configfs(se_sess);
622 	transport_deregister_session(se_sess);
623 }
624 EXPORT_SYMBOL(target_remove_session);
625 
626 static void target_remove_from_state_list(struct se_cmd *cmd)
627 {
628 	struct se_device *dev = cmd->se_dev;
629 	unsigned long flags;
630 
631 	if (!dev)
632 		return;
633 
634 	spin_lock_irqsave(&dev->execute_task_lock, flags);
635 	if (cmd->state_active) {
636 		list_del(&cmd->state_list);
637 		cmd->state_active = false;
638 	}
639 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
640 }
641 
642 /*
643  * This function is called by the target core after the target core has
644  * finished processing a SCSI command or SCSI TMF. Both the regular command
645  * processing code and the code for aborting commands can call this
646  * function. CMD_T_STOP is set if and only if another thread is waiting
647  * inside transport_wait_for_tasks() for t_transport_stop_comp.
648  */
649 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
650 {
651 	unsigned long flags;
652 
653 	target_remove_from_state_list(cmd);
654 
655 	/*
656 	 * Clear struct se_cmd->se_lun before the handoff to FE.
657 	 */
658 	cmd->se_lun = NULL;
659 
660 	spin_lock_irqsave(&cmd->t_state_lock, flags);
661 	/*
662 	 * Determine if frontend context caller is requesting the stopping of
663 	 * this command for frontend exceptions.
664 	 */
665 	if (cmd->transport_state & CMD_T_STOP) {
666 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
667 			__func__, __LINE__, cmd->tag);
668 
669 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
670 
671 		complete_all(&cmd->t_transport_stop_comp);
672 		return 1;
673 	}
674 	cmd->transport_state &= ~CMD_T_ACTIVE;
675 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
676 
677 	/*
678 	 * Some fabric modules like tcm_loop can release their internally
679 	 * allocated I/O reference and struct se_cmd now.
680 	 *
681 	 * Fabric modules are expected to return '1' here if the se_cmd being
682 	 * passed is released at this point, or zero if not being released.
683 	 */
684 	return cmd->se_tfo->check_stop_free(cmd);
685 }
686 
687 static void transport_lun_remove_cmd(struct se_cmd *cmd)
688 {
689 	struct se_lun *lun = cmd->se_lun;
690 
691 	if (!lun)
692 		return;
693 
694 	if (cmpxchg(&cmd->lun_ref_active, true, false))
695 		percpu_ref_put(&lun->lun_ref);
696 }
697 
698 int transport_cmd_finish_abort(struct se_cmd *cmd)
699 {
700 	bool send_tas = cmd->transport_state & CMD_T_TAS;
701 	bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
702 	int ret = 0;
703 
704 	if (send_tas)
705 		transport_send_task_abort(cmd);
706 
707 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
708 		transport_lun_remove_cmd(cmd);
709 	/*
710 	 * Allow the fabric driver to unmap any resources before
711 	 * releasing the descriptor via TFO->release_cmd()
712 	 */
713 	if (!send_tas)
714 		cmd->se_tfo->aborted_task(cmd);
715 
716 	if (transport_cmd_check_stop_to_fabric(cmd))
717 		return 1;
718 	if (!send_tas && ack_kref)
719 		ret = target_put_sess_cmd(cmd);
720 
721 	return ret;
722 }
723 
724 static void target_complete_failure_work(struct work_struct *work)
725 {
726 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
727 
728 	transport_generic_request_failure(cmd,
729 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
730 }
731 
732 /*
733  * Used when asking transport to copy Sense Data from the underlying
734  * Linux/SCSI struct scsi_cmnd
735  */
736 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
737 {
738 	struct se_device *dev = cmd->se_dev;
739 
740 	WARN_ON(!cmd->se_lun);
741 
742 	if (!dev)
743 		return NULL;
744 
745 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
746 		return NULL;
747 
748 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
749 
750 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
751 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
752 	return cmd->sense_buffer;
753 }
754 
755 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
756 {
757 	unsigned char *cmd_sense_buf;
758 	unsigned long flags;
759 
760 	spin_lock_irqsave(&cmd->t_state_lock, flags);
761 	cmd_sense_buf = transport_get_sense_buffer(cmd);
762 	if (!cmd_sense_buf) {
763 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
764 		return;
765 	}
766 
767 	cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
768 	memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
769 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
770 }
771 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
772 
773 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
774 {
775 	struct se_device *dev = cmd->se_dev;
776 	int success;
777 	unsigned long flags;
778 
779 	cmd->scsi_status = scsi_status;
780 
781 	spin_lock_irqsave(&cmd->t_state_lock, flags);
782 	switch (cmd->scsi_status) {
783 	case SAM_STAT_CHECK_CONDITION:
784 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
785 			success = 1;
786 		else
787 			success = 0;
788 		break;
789 	default:
790 		success = 1;
791 		break;
792 	}
793 
794 	/*
795 	 * Check for case where an explicit ABORT_TASK has been received
796 	 * and transport_wait_for_tasks() will be waiting for completion..
797 	 */
798 	if (cmd->transport_state & CMD_T_ABORTED ||
799 	    cmd->transport_state & CMD_T_STOP) {
800 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
801 		/*
802 		 * If COMPARE_AND_WRITE was stopped by __transport_wait_for_tasks(),
803 		 * release se_device->caw_sem obtained by sbc_compare_and_write()
804 		 * since target_complete_ok_work() or target_complete_failure_work()
805 		 * won't be called to invoke the normal CAW completion callbacks.
806 		 */
807 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
808 			up(&dev->caw_sem);
809 		}
810 		complete_all(&cmd->t_transport_stop_comp);
811 		return;
812 	} else if (!success) {
813 		INIT_WORK(&cmd->work, target_complete_failure_work);
814 	} else {
815 		INIT_WORK(&cmd->work, target_complete_ok_work);
816 	}
817 
818 	cmd->t_state = TRANSPORT_COMPLETE;
819 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
820 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
821 
822 	if (cmd->se_cmd_flags & SCF_USE_CPUID)
823 		queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
824 	else
825 		queue_work(target_completion_wq, &cmd->work);
826 }
827 EXPORT_SYMBOL(target_complete_cmd);
828 
829 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
830 {
831 	if ((scsi_status == SAM_STAT_GOOD ||
832 	     cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
833 	    length < cmd->data_length) {
834 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
835 			cmd->residual_count += cmd->data_length - length;
836 		} else {
837 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
838 			cmd->residual_count = cmd->data_length - length;
839 		}
840 
841 		cmd->data_length = length;
842 	}
843 
844 	target_complete_cmd(cmd, scsi_status);
845 }
846 EXPORT_SYMBOL(target_complete_cmd_with_length);
847 
848 static void target_add_to_state_list(struct se_cmd *cmd)
849 {
850 	struct se_device *dev = cmd->se_dev;
851 	unsigned long flags;
852 
853 	spin_lock_irqsave(&dev->execute_task_lock, flags);
854 	if (!cmd->state_active) {
855 		list_add_tail(&cmd->state_list, &dev->state_list);
856 		cmd->state_active = true;
857 	}
858 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
859 }
860 
861 /*
862  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
863  */
864 static void transport_write_pending_qf(struct se_cmd *cmd);
865 static void transport_complete_qf(struct se_cmd *cmd);
866 
867 void target_qf_do_work(struct work_struct *work)
868 {
869 	struct se_device *dev = container_of(work, struct se_device,
870 					qf_work_queue);
871 	LIST_HEAD(qf_cmd_list);
872 	struct se_cmd *cmd, *cmd_tmp;
873 
874 	spin_lock_irq(&dev->qf_cmd_lock);
875 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
876 	spin_unlock_irq(&dev->qf_cmd_lock);
877 
878 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
879 		list_del(&cmd->se_qf_node);
880 		atomic_dec_mb(&dev->dev_qf_count);
881 
882 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
883 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
884 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
885 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
886 			: "UNKNOWN");
887 
888 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
889 			transport_write_pending_qf(cmd);
890 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
891 			 cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
892 			transport_complete_qf(cmd);
893 	}
894 }
895 
896 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
897 {
898 	switch (cmd->data_direction) {
899 	case DMA_NONE:
900 		return "NONE";
901 	case DMA_FROM_DEVICE:
902 		return "READ";
903 	case DMA_TO_DEVICE:
904 		return "WRITE";
905 	case DMA_BIDIRECTIONAL:
906 		return "BIDI";
907 	default:
908 		break;
909 	}
910 
911 	return "UNKNOWN";
912 }
913 
914 void transport_dump_dev_state(
915 	struct se_device *dev,
916 	char *b,
917 	int *bl)
918 {
919 	*bl += sprintf(b + *bl, "Status: ");
920 	if (dev->export_count)
921 		*bl += sprintf(b + *bl, "ACTIVATED");
922 	else
923 		*bl += sprintf(b + *bl, "DEACTIVATED");
924 
925 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
926 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
927 		dev->dev_attrib.block_size,
928 		dev->dev_attrib.hw_max_sectors);
929 	*bl += sprintf(b + *bl, "        ");
930 }
931 
932 void transport_dump_vpd_proto_id(
933 	struct t10_vpd *vpd,
934 	unsigned char *p_buf,
935 	int p_buf_len)
936 {
937 	unsigned char buf[VPD_TMP_BUF_SIZE];
938 	int len;
939 
940 	memset(buf, 0, VPD_TMP_BUF_SIZE);
941 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
942 
943 	switch (vpd->protocol_identifier) {
944 	case 0x00:
945 		sprintf(buf+len, "Fibre Channel\n");
946 		break;
947 	case 0x10:
948 		sprintf(buf+len, "Parallel SCSI\n");
949 		break;
950 	case 0x20:
951 		sprintf(buf+len, "SSA\n");
952 		break;
953 	case 0x30:
954 		sprintf(buf+len, "IEEE 1394\n");
955 		break;
956 	case 0x40:
957 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
958 				" Protocol\n");
959 		break;
960 	case 0x50:
961 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
962 		break;
963 	case 0x60:
964 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
965 		break;
966 	case 0x70:
967 		sprintf(buf+len, "Automation/Drive Interface Transport"
968 				" Protocol\n");
969 		break;
970 	case 0x80:
971 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
972 		break;
973 	default:
974 		sprintf(buf+len, "Unknown 0x%02x\n",
975 				vpd->protocol_identifier);
976 		break;
977 	}
978 
979 	if (p_buf)
980 		strncpy(p_buf, buf, p_buf_len);
981 	else
982 		pr_debug("%s", buf);
983 }
984 
985 void
986 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
987 {
988 	/*
989 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
990 	 *
991 	 * from spc3r23.pdf section 7.5.1
992 	 */
993 	 if (page_83[1] & 0x80) {
994 		vpd->protocol_identifier = (page_83[0] & 0xf0);
995 		vpd->protocol_identifier_set = 1;
996 		transport_dump_vpd_proto_id(vpd, NULL, 0);
997 	}
998 }
999 EXPORT_SYMBOL(transport_set_vpd_proto_id);
1000 
1001 int transport_dump_vpd_assoc(
1002 	struct t10_vpd *vpd,
1003 	unsigned char *p_buf,
1004 	int p_buf_len)
1005 {
1006 	unsigned char buf[VPD_TMP_BUF_SIZE];
1007 	int ret = 0;
1008 	int len;
1009 
1010 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1011 	len = sprintf(buf, "T10 VPD Identifier Association: ");
1012 
1013 	switch (vpd->association) {
1014 	case 0x00:
1015 		sprintf(buf+len, "addressed logical unit\n");
1016 		break;
1017 	case 0x10:
1018 		sprintf(buf+len, "target port\n");
1019 		break;
1020 	case 0x20:
1021 		sprintf(buf+len, "SCSI target device\n");
1022 		break;
1023 	default:
1024 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
1025 		ret = -EINVAL;
1026 		break;
1027 	}
1028 
1029 	if (p_buf)
1030 		strncpy(p_buf, buf, p_buf_len);
1031 	else
1032 		pr_debug("%s", buf);
1033 
1034 	return ret;
1035 }
1036 
1037 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
1038 {
1039 	/*
1040 	 * The VPD identification association..
1041 	 *
1042 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
1043 	 */
1044 	vpd->association = (page_83[1] & 0x30);
1045 	return transport_dump_vpd_assoc(vpd, NULL, 0);
1046 }
1047 EXPORT_SYMBOL(transport_set_vpd_assoc);
1048 
1049 int transport_dump_vpd_ident_type(
1050 	struct t10_vpd *vpd,
1051 	unsigned char *p_buf,
1052 	int p_buf_len)
1053 {
1054 	unsigned char buf[VPD_TMP_BUF_SIZE];
1055 	int ret = 0;
1056 	int len;
1057 
1058 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1059 	len = sprintf(buf, "T10 VPD Identifier Type: ");
1060 
1061 	switch (vpd->device_identifier_type) {
1062 	case 0x00:
1063 		sprintf(buf+len, "Vendor specific\n");
1064 		break;
1065 	case 0x01:
1066 		sprintf(buf+len, "T10 Vendor ID based\n");
1067 		break;
1068 	case 0x02:
1069 		sprintf(buf+len, "EUI-64 based\n");
1070 		break;
1071 	case 0x03:
1072 		sprintf(buf+len, "NAA\n");
1073 		break;
1074 	case 0x04:
1075 		sprintf(buf+len, "Relative target port identifier\n");
1076 		break;
1077 	case 0x08:
1078 		sprintf(buf+len, "SCSI name string\n");
1079 		break;
1080 	default:
1081 		sprintf(buf+len, "Unsupported: 0x%02x\n",
1082 				vpd->device_identifier_type);
1083 		ret = -EINVAL;
1084 		break;
1085 	}
1086 
1087 	if (p_buf) {
1088 		if (p_buf_len < strlen(buf)+1)
1089 			return -EINVAL;
1090 		strncpy(p_buf, buf, p_buf_len);
1091 	} else {
1092 		pr_debug("%s", buf);
1093 	}
1094 
1095 	return ret;
1096 }
1097 
1098 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1099 {
1100 	/*
1101 	 * The VPD identifier type..
1102 	 *
1103 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1104 	 */
1105 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1106 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1107 }
1108 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1109 
1110 int transport_dump_vpd_ident(
1111 	struct t10_vpd *vpd,
1112 	unsigned char *p_buf,
1113 	int p_buf_len)
1114 {
1115 	unsigned char buf[VPD_TMP_BUF_SIZE];
1116 	int ret = 0;
1117 
1118 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1119 
1120 	switch (vpd->device_identifier_code_set) {
1121 	case 0x01: /* Binary */
1122 		snprintf(buf, sizeof(buf),
1123 			"T10 VPD Binary Device Identifier: %s\n",
1124 			&vpd->device_identifier[0]);
1125 		break;
1126 	case 0x02: /* ASCII */
1127 		snprintf(buf, sizeof(buf),
1128 			"T10 VPD ASCII Device Identifier: %s\n",
1129 			&vpd->device_identifier[0]);
1130 		break;
1131 	case 0x03: /* UTF-8 */
1132 		snprintf(buf, sizeof(buf),
1133 			"T10 VPD UTF-8 Device Identifier: %s\n",
1134 			&vpd->device_identifier[0]);
1135 		break;
1136 	default:
1137 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1138 			" 0x%02x", vpd->device_identifier_code_set);
1139 		ret = -EINVAL;
1140 		break;
1141 	}
1142 
1143 	if (p_buf)
1144 		strncpy(p_buf, buf, p_buf_len);
1145 	else
1146 		pr_debug("%s", buf);
1147 
1148 	return ret;
1149 }
1150 
1151 int
1152 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1153 {
1154 	static const char hex_str[] = "0123456789abcdef";
1155 	int j = 0, i = 4; /* offset to start of the identifier */
1156 
1157 	/*
1158 	 * The VPD Code Set (encoding)
1159 	 *
1160 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1161 	 */
1162 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1163 	switch (vpd->device_identifier_code_set) {
1164 	case 0x01: /* Binary */
1165 		vpd->device_identifier[j++] =
1166 				hex_str[vpd->device_identifier_type];
1167 		while (i < (4 + page_83[3])) {
1168 			vpd->device_identifier[j++] =
1169 				hex_str[(page_83[i] & 0xf0) >> 4];
1170 			vpd->device_identifier[j++] =
1171 				hex_str[page_83[i] & 0x0f];
1172 			i++;
1173 		}
1174 		break;
1175 	case 0x02: /* ASCII */
1176 	case 0x03: /* UTF-8 */
1177 		while (i < (4 + page_83[3]))
1178 			vpd->device_identifier[j++] = page_83[i++];
1179 		break;
1180 	default:
1181 		break;
1182 	}
1183 
1184 	return transport_dump_vpd_ident(vpd, NULL, 0);
1185 }
1186 EXPORT_SYMBOL(transport_set_vpd_ident);
1187 
1188 static sense_reason_t
1189 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1190 			       unsigned int size)
1191 {
1192 	u32 mtl;
1193 
1194 	if (!cmd->se_tfo->max_data_sg_nents)
1195 		return TCM_NO_SENSE;
1196 	/*
1197 	 * Check if fabric enforced maximum SGL entries per I/O descriptor
1198 	 * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1199 	 * residual_count and reduce original cmd->data_length to maximum
1200 	 * length based on single PAGE_SIZE entry scatter-lists.
1201 	 */
1202 	mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1203 	if (cmd->data_length > mtl) {
1204 		/*
1205 		 * If an existing CDB overflow is present, calculate new residual
1206 		 * based on CDB size minus fabric maximum transfer length.
1207 		 *
1208 		 * If an existing CDB underflow is present, calculate new residual
1209 		 * based on original cmd->data_length minus fabric maximum transfer
1210 		 * length.
1211 		 *
1212 		 * Otherwise, set the underflow residual based on cmd->data_length
1213 		 * minus fabric maximum transfer length.
1214 		 */
1215 		if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1216 			cmd->residual_count = (size - mtl);
1217 		} else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1218 			u32 orig_dl = size + cmd->residual_count;
1219 			cmd->residual_count = (orig_dl - mtl);
1220 		} else {
1221 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1222 			cmd->residual_count = (cmd->data_length - mtl);
1223 		}
1224 		cmd->data_length = mtl;
1225 		/*
1226 		 * Reset sbc_check_prot() calculated protection payload
1227 		 * length based upon the new smaller MTL.
1228 		 */
1229 		if (cmd->prot_length) {
1230 			u32 sectors = (mtl / dev->dev_attrib.block_size);
1231 			cmd->prot_length = dev->prot_length * sectors;
1232 		}
1233 	}
1234 	return TCM_NO_SENSE;
1235 }
1236 
1237 sense_reason_t
1238 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1239 {
1240 	struct se_device *dev = cmd->se_dev;
1241 
1242 	if (cmd->unknown_data_length) {
1243 		cmd->data_length = size;
1244 	} else if (size != cmd->data_length) {
1245 		pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1246 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1247 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1248 				cmd->data_length, size, cmd->t_task_cdb[0]);
1249 
1250 		if (cmd->data_direction == DMA_TO_DEVICE) {
1251 			if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1252 				pr_err_ratelimited("Rejecting underflow/overflow"
1253 						   " for WRITE data CDB\n");
1254 				return TCM_INVALID_CDB_FIELD;
1255 			}
1256 			/*
1257 			 * Some fabric drivers like iscsi-target still expect to
1258 			 * always reject overflow writes.  Reject this case until
1259 			 * full fabric driver level support for overflow writes
1260 			 * is introduced tree-wide.
1261 			 */
1262 			if (size > cmd->data_length) {
1263 				pr_err_ratelimited("Rejecting overflow for"
1264 						   " WRITE control CDB\n");
1265 				return TCM_INVALID_CDB_FIELD;
1266 			}
1267 		}
1268 		/*
1269 		 * Reject READ_* or WRITE_* with overflow/underflow for
1270 		 * type SCF_SCSI_DATA_CDB.
1271 		 */
1272 		if (dev->dev_attrib.block_size != 512)  {
1273 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1274 				" CDB on non 512-byte sector setup subsystem"
1275 				" plugin: %s\n", dev->transport->name);
1276 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1277 			return TCM_INVALID_CDB_FIELD;
1278 		}
1279 		/*
1280 		 * For the overflow case keep the existing fabric provided
1281 		 * ->data_length.  Otherwise for the underflow case, reset
1282 		 * ->data_length to the smaller SCSI expected data transfer
1283 		 * length.
1284 		 */
1285 		if (size > cmd->data_length) {
1286 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1287 			cmd->residual_count = (size - cmd->data_length);
1288 		} else {
1289 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1290 			cmd->residual_count = (cmd->data_length - size);
1291 			cmd->data_length = size;
1292 		}
1293 	}
1294 
1295 	return target_check_max_data_sg_nents(cmd, dev, size);
1296 
1297 }
1298 
1299 /*
1300  * Used by fabric modules containing a local struct se_cmd within their
1301  * fabric dependent per I/O descriptor.
1302  *
1303  * Preserves the value of @cmd->tag.
1304  */
1305 void transport_init_se_cmd(
1306 	struct se_cmd *cmd,
1307 	const struct target_core_fabric_ops *tfo,
1308 	struct se_session *se_sess,
1309 	u32 data_length,
1310 	int data_direction,
1311 	int task_attr,
1312 	unsigned char *sense_buffer)
1313 {
1314 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1315 	INIT_LIST_HEAD(&cmd->se_qf_node);
1316 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1317 	INIT_LIST_HEAD(&cmd->state_list);
1318 	init_completion(&cmd->t_transport_stop_comp);
1319 	cmd->compl = NULL;
1320 	spin_lock_init(&cmd->t_state_lock);
1321 	INIT_WORK(&cmd->work, NULL);
1322 	kref_init(&cmd->cmd_kref);
1323 
1324 	cmd->se_tfo = tfo;
1325 	cmd->se_sess = se_sess;
1326 	cmd->data_length = data_length;
1327 	cmd->data_direction = data_direction;
1328 	cmd->sam_task_attr = task_attr;
1329 	cmd->sense_buffer = sense_buffer;
1330 
1331 	cmd->state_active = false;
1332 }
1333 EXPORT_SYMBOL(transport_init_se_cmd);
1334 
1335 static sense_reason_t
1336 transport_check_alloc_task_attr(struct se_cmd *cmd)
1337 {
1338 	struct se_device *dev = cmd->se_dev;
1339 
1340 	/*
1341 	 * Check if SAM Task Attribute emulation is enabled for this
1342 	 * struct se_device storage object
1343 	 */
1344 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1345 		return 0;
1346 
1347 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1348 		pr_debug("SAM Task Attribute ACA"
1349 			" emulation is not supported\n");
1350 		return TCM_INVALID_CDB_FIELD;
1351 	}
1352 
1353 	return 0;
1354 }
1355 
1356 sense_reason_t
1357 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1358 {
1359 	struct se_device *dev = cmd->se_dev;
1360 	sense_reason_t ret;
1361 
1362 	/*
1363 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1364 	 * for VARIABLE_LENGTH_CMD
1365 	 */
1366 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1367 		pr_err("Received SCSI CDB with command_size: %d that"
1368 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1369 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1370 		return TCM_INVALID_CDB_FIELD;
1371 	}
1372 	/*
1373 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1374 	 * allocate the additional extended CDB buffer now..  Otherwise
1375 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1376 	 */
1377 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1378 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1379 						GFP_KERNEL);
1380 		if (!cmd->t_task_cdb) {
1381 			pr_err("Unable to allocate cmd->t_task_cdb"
1382 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1383 				scsi_command_size(cdb),
1384 				(unsigned long)sizeof(cmd->__t_task_cdb));
1385 			return TCM_OUT_OF_RESOURCES;
1386 		}
1387 	} else
1388 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1389 	/*
1390 	 * Copy the original CDB into cmd->
1391 	 */
1392 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1393 
1394 	trace_target_sequencer_start(cmd);
1395 
1396 	ret = dev->transport->parse_cdb(cmd);
1397 	if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1398 		pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1399 				    cmd->se_tfo->get_fabric_name(),
1400 				    cmd->se_sess->se_node_acl->initiatorname,
1401 				    cmd->t_task_cdb[0]);
1402 	if (ret)
1403 		return ret;
1404 
1405 	ret = transport_check_alloc_task_attr(cmd);
1406 	if (ret)
1407 		return ret;
1408 
1409 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1410 	atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1411 	return 0;
1412 }
1413 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1414 
1415 /*
1416  * Used by fabric module frontends to queue tasks directly.
1417  * May only be used from process context.
1418  */
1419 int transport_handle_cdb_direct(
1420 	struct se_cmd *cmd)
1421 {
1422 	sense_reason_t ret;
1423 
1424 	if (!cmd->se_lun) {
1425 		dump_stack();
1426 		pr_err("cmd->se_lun is NULL\n");
1427 		return -EINVAL;
1428 	}
1429 	if (in_interrupt()) {
1430 		dump_stack();
1431 		pr_err("transport_generic_handle_cdb cannot be called"
1432 				" from interrupt context\n");
1433 		return -EINVAL;
1434 	}
1435 	/*
1436 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1437 	 * outstanding descriptors are handled correctly during shutdown via
1438 	 * transport_wait_for_tasks()
1439 	 *
1440 	 * Also, we don't take cmd->t_state_lock here as we only expect
1441 	 * this to be called for initial descriptor submission.
1442 	 */
1443 	cmd->t_state = TRANSPORT_NEW_CMD;
1444 	cmd->transport_state |= CMD_T_ACTIVE;
1445 
1446 	/*
1447 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1448 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1449 	 * and call transport_generic_request_failure() if necessary..
1450 	 */
1451 	ret = transport_generic_new_cmd(cmd);
1452 	if (ret)
1453 		transport_generic_request_failure(cmd, ret);
1454 	return 0;
1455 }
1456 EXPORT_SYMBOL(transport_handle_cdb_direct);
1457 
1458 sense_reason_t
1459 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1460 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1461 {
1462 	if (!sgl || !sgl_count)
1463 		return 0;
1464 
1465 	/*
1466 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1467 	 * scatterlists already have been set to follow what the fabric
1468 	 * passes for the original expected data transfer length.
1469 	 */
1470 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1471 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1472 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1473 		return TCM_INVALID_CDB_FIELD;
1474 	}
1475 
1476 	cmd->t_data_sg = sgl;
1477 	cmd->t_data_nents = sgl_count;
1478 	cmd->t_bidi_data_sg = sgl_bidi;
1479 	cmd->t_bidi_data_nents = sgl_bidi_count;
1480 
1481 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1482 	return 0;
1483 }
1484 
1485 /**
1486  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1487  * 			 se_cmd + use pre-allocated SGL memory.
1488  *
1489  * @se_cmd: command descriptor to submit
1490  * @se_sess: associated se_sess for endpoint
1491  * @cdb: pointer to SCSI CDB
1492  * @sense: pointer to SCSI sense buffer
1493  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1494  * @data_length: fabric expected data transfer length
1495  * @task_attr: SAM task attribute
1496  * @data_dir: DMA data direction
1497  * @flags: flags for command submission from target_sc_flags_tables
1498  * @sgl: struct scatterlist memory for unidirectional mapping
1499  * @sgl_count: scatterlist count for unidirectional mapping
1500  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1501  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1502  * @sgl_prot: struct scatterlist memory protection information
1503  * @sgl_prot_count: scatterlist count for protection information
1504  *
1505  * Task tags are supported if the caller has set @se_cmd->tag.
1506  *
1507  * Returns non zero to signal active I/O shutdown failure.  All other
1508  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1509  * but still return zero here.
1510  *
1511  * This may only be called from process context, and also currently
1512  * assumes internal allocation of fabric payload buffer by target-core.
1513  */
1514 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1515 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1516 		u32 data_length, int task_attr, int data_dir, int flags,
1517 		struct scatterlist *sgl, u32 sgl_count,
1518 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1519 		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1520 {
1521 	struct se_portal_group *se_tpg;
1522 	sense_reason_t rc;
1523 	int ret;
1524 
1525 	se_tpg = se_sess->se_tpg;
1526 	BUG_ON(!se_tpg);
1527 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1528 	BUG_ON(in_interrupt());
1529 	/*
1530 	 * Initialize se_cmd for target operation.  From this point
1531 	 * exceptions are handled by sending exception status via
1532 	 * target_core_fabric_ops->queue_status() callback
1533 	 */
1534 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1535 				data_length, data_dir, task_attr, sense);
1536 
1537 	if (flags & TARGET_SCF_USE_CPUID)
1538 		se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1539 	else
1540 		se_cmd->cpuid = WORK_CPU_UNBOUND;
1541 
1542 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1543 		se_cmd->unknown_data_length = 1;
1544 	/*
1545 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1546 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1547 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1548 	 * kref_put() to happen during fabric packet acknowledgement.
1549 	 */
1550 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1551 	if (ret)
1552 		return ret;
1553 	/*
1554 	 * Signal bidirectional data payloads to target-core
1555 	 */
1556 	if (flags & TARGET_SCF_BIDI_OP)
1557 		se_cmd->se_cmd_flags |= SCF_BIDI;
1558 	/*
1559 	 * Locate se_lun pointer and attach it to struct se_cmd
1560 	 */
1561 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1562 	if (rc) {
1563 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1564 		target_put_sess_cmd(se_cmd);
1565 		return 0;
1566 	}
1567 
1568 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1569 	if (rc != 0) {
1570 		transport_generic_request_failure(se_cmd, rc);
1571 		return 0;
1572 	}
1573 
1574 	/*
1575 	 * Save pointers for SGLs containing protection information,
1576 	 * if present.
1577 	 */
1578 	if (sgl_prot_count) {
1579 		se_cmd->t_prot_sg = sgl_prot;
1580 		se_cmd->t_prot_nents = sgl_prot_count;
1581 		se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1582 	}
1583 
1584 	/*
1585 	 * When a non zero sgl_count has been passed perform SGL passthrough
1586 	 * mapping for pre-allocated fabric memory instead of having target
1587 	 * core perform an internal SGL allocation..
1588 	 */
1589 	if (sgl_count != 0) {
1590 		BUG_ON(!sgl);
1591 
1592 		/*
1593 		 * A work-around for tcm_loop as some userspace code via
1594 		 * scsi-generic do not memset their associated read buffers,
1595 		 * so go ahead and do that here for type non-data CDBs.  Also
1596 		 * note that this is currently guaranteed to be a single SGL
1597 		 * for this case by target core in target_setup_cmd_from_cdb()
1598 		 * -> transport_generic_cmd_sequencer().
1599 		 */
1600 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1601 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1602 			unsigned char *buf = NULL;
1603 
1604 			if (sgl)
1605 				buf = kmap(sg_page(sgl)) + sgl->offset;
1606 
1607 			if (buf) {
1608 				memset(buf, 0, sgl->length);
1609 				kunmap(sg_page(sgl));
1610 			}
1611 		}
1612 
1613 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1614 				sgl_bidi, sgl_bidi_count);
1615 		if (rc != 0) {
1616 			transport_generic_request_failure(se_cmd, rc);
1617 			return 0;
1618 		}
1619 	}
1620 
1621 	/*
1622 	 * Check if we need to delay processing because of ALUA
1623 	 * Active/NonOptimized primary access state..
1624 	 */
1625 	core_alua_check_nonop_delay(se_cmd);
1626 
1627 	transport_handle_cdb_direct(se_cmd);
1628 	return 0;
1629 }
1630 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1631 
1632 /**
1633  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1634  *
1635  * @se_cmd: command descriptor to submit
1636  * @se_sess: associated se_sess for endpoint
1637  * @cdb: pointer to SCSI CDB
1638  * @sense: pointer to SCSI sense buffer
1639  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1640  * @data_length: fabric expected data transfer length
1641  * @task_attr: SAM task attribute
1642  * @data_dir: DMA data direction
1643  * @flags: flags for command submission from target_sc_flags_tables
1644  *
1645  * Task tags are supported if the caller has set @se_cmd->tag.
1646  *
1647  * Returns non zero to signal active I/O shutdown failure.  All other
1648  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1649  * but still return zero here.
1650  *
1651  * This may only be called from process context, and also currently
1652  * assumes internal allocation of fabric payload buffer by target-core.
1653  *
1654  * It also assumes interal target core SGL memory allocation.
1655  */
1656 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1657 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1658 		u32 data_length, int task_attr, int data_dir, int flags)
1659 {
1660 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1661 			unpacked_lun, data_length, task_attr, data_dir,
1662 			flags, NULL, 0, NULL, 0, NULL, 0);
1663 }
1664 EXPORT_SYMBOL(target_submit_cmd);
1665 
1666 static void target_complete_tmr_failure(struct work_struct *work)
1667 {
1668 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1669 
1670 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1671 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1672 
1673 	transport_lun_remove_cmd(se_cmd);
1674 	transport_cmd_check_stop_to_fabric(se_cmd);
1675 }
1676 
1677 static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
1678 				       u64 *unpacked_lun)
1679 {
1680 	struct se_cmd *se_cmd;
1681 	unsigned long flags;
1682 	bool ret = false;
1683 
1684 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
1685 	list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
1686 		if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1687 			continue;
1688 
1689 		if (se_cmd->tag == tag) {
1690 			*unpacked_lun = se_cmd->orig_fe_lun;
1691 			ret = true;
1692 			break;
1693 		}
1694 	}
1695 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
1696 
1697 	return ret;
1698 }
1699 
1700 /**
1701  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1702  *                     for TMR CDBs
1703  *
1704  * @se_cmd: command descriptor to submit
1705  * @se_sess: associated se_sess for endpoint
1706  * @sense: pointer to SCSI sense buffer
1707  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1708  * @fabric_tmr_ptr: fabric context for TMR req
1709  * @tm_type: Type of TM request
1710  * @gfp: gfp type for caller
1711  * @tag: referenced task tag for TMR_ABORT_TASK
1712  * @flags: submit cmd flags
1713  *
1714  * Callable from all contexts.
1715  **/
1716 
1717 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1718 		unsigned char *sense, u64 unpacked_lun,
1719 		void *fabric_tmr_ptr, unsigned char tm_type,
1720 		gfp_t gfp, u64 tag, int flags)
1721 {
1722 	struct se_portal_group *se_tpg;
1723 	int ret;
1724 
1725 	se_tpg = se_sess->se_tpg;
1726 	BUG_ON(!se_tpg);
1727 
1728 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1729 			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1730 	/*
1731 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1732 	 * allocation failure.
1733 	 */
1734 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1735 	if (ret < 0)
1736 		return -ENOMEM;
1737 
1738 	if (tm_type == TMR_ABORT_TASK)
1739 		se_cmd->se_tmr_req->ref_task_tag = tag;
1740 
1741 	/* See target_submit_cmd for commentary */
1742 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1743 	if (ret) {
1744 		core_tmr_release_req(se_cmd->se_tmr_req);
1745 		return ret;
1746 	}
1747 	/*
1748 	 * If this is ABORT_TASK with no explicit fabric provided LUN,
1749 	 * go ahead and search active session tags for a match to figure
1750 	 * out unpacked_lun for the original se_cmd.
1751 	 */
1752 	if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
1753 		if (!target_lookup_lun_from_tag(se_sess, tag, &unpacked_lun))
1754 			goto failure;
1755 	}
1756 
1757 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1758 	if (ret)
1759 		goto failure;
1760 
1761 	transport_generic_handle_tmr(se_cmd);
1762 	return 0;
1763 
1764 	/*
1765 	 * For callback during failure handling, push this work off
1766 	 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1767 	 */
1768 failure:
1769 	INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1770 	schedule_work(&se_cmd->work);
1771 	return 0;
1772 }
1773 EXPORT_SYMBOL(target_submit_tmr);
1774 
1775 /*
1776  * Handle SAM-esque emulation for generic transport request failures.
1777  */
1778 void transport_generic_request_failure(struct se_cmd *cmd,
1779 		sense_reason_t sense_reason)
1780 {
1781 	int ret = 0, post_ret = 0;
1782 
1783 	pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
1784 		 sense_reason);
1785 	target_show_cmd("-----[ ", cmd);
1786 
1787 	/*
1788 	 * For SAM Task Attribute emulation for failed struct se_cmd
1789 	 */
1790 	transport_complete_task_attr(cmd);
1791 
1792 	/*
1793 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1794 	 * callback is expected to drop the per device ->caw_sem.
1795 	 */
1796 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1797 	     cmd->transport_complete_callback)
1798 		cmd->transport_complete_callback(cmd, false, &post_ret);
1799 
1800 	if (transport_check_aborted_status(cmd, 1))
1801 		return;
1802 
1803 	switch (sense_reason) {
1804 	case TCM_NON_EXISTENT_LUN:
1805 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1806 	case TCM_INVALID_CDB_FIELD:
1807 	case TCM_INVALID_PARAMETER_LIST:
1808 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1809 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1810 	case TCM_UNKNOWN_MODE_PAGE:
1811 	case TCM_WRITE_PROTECTED:
1812 	case TCM_ADDRESS_OUT_OF_RANGE:
1813 	case TCM_CHECK_CONDITION_ABORT_CMD:
1814 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1815 	case TCM_CHECK_CONDITION_NOT_READY:
1816 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1817 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1818 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1819 	case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1820 	case TCM_TOO_MANY_TARGET_DESCS:
1821 	case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1822 	case TCM_TOO_MANY_SEGMENT_DESCS:
1823 	case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1824 		break;
1825 	case TCM_OUT_OF_RESOURCES:
1826 		cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
1827 		goto queue_status;
1828 	case TCM_LUN_BUSY:
1829 		cmd->scsi_status = SAM_STAT_BUSY;
1830 		goto queue_status;
1831 	case TCM_RESERVATION_CONFLICT:
1832 		/*
1833 		 * No SENSE Data payload for this case, set SCSI Status
1834 		 * and queue the response to $FABRIC_MOD.
1835 		 *
1836 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1837 		 */
1838 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1839 		/*
1840 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1841 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1842 		 * CONFLICT STATUS.
1843 		 *
1844 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1845 		 */
1846 		if (cmd->se_sess &&
1847 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1848 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1849 					       cmd->orig_fe_lun, 0x2C,
1850 					ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1851 		}
1852 
1853 		goto queue_status;
1854 	default:
1855 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1856 			cmd->t_task_cdb[0], sense_reason);
1857 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1858 		break;
1859 	}
1860 
1861 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1862 	if (ret)
1863 		goto queue_full;
1864 
1865 check_stop:
1866 	transport_lun_remove_cmd(cmd);
1867 	transport_cmd_check_stop_to_fabric(cmd);
1868 	return;
1869 
1870 queue_status:
1871 	trace_target_cmd_complete(cmd);
1872 	ret = cmd->se_tfo->queue_status(cmd);
1873 	if (!ret)
1874 		goto check_stop;
1875 queue_full:
1876 	transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1877 }
1878 EXPORT_SYMBOL(transport_generic_request_failure);
1879 
1880 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1881 {
1882 	sense_reason_t ret;
1883 
1884 	if (!cmd->execute_cmd) {
1885 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1886 		goto err;
1887 	}
1888 	if (do_checks) {
1889 		/*
1890 		 * Check for an existing UNIT ATTENTION condition after
1891 		 * target_handle_task_attr() has done SAM task attr
1892 		 * checking, and possibly have already defered execution
1893 		 * out to target_restart_delayed_cmds() context.
1894 		 */
1895 		ret = target_scsi3_ua_check(cmd);
1896 		if (ret)
1897 			goto err;
1898 
1899 		ret = target_alua_state_check(cmd);
1900 		if (ret)
1901 			goto err;
1902 
1903 		ret = target_check_reservation(cmd);
1904 		if (ret) {
1905 			cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1906 			goto err;
1907 		}
1908 	}
1909 
1910 	ret = cmd->execute_cmd(cmd);
1911 	if (!ret)
1912 		return;
1913 err:
1914 	spin_lock_irq(&cmd->t_state_lock);
1915 	cmd->transport_state &= ~CMD_T_SENT;
1916 	spin_unlock_irq(&cmd->t_state_lock);
1917 
1918 	transport_generic_request_failure(cmd, ret);
1919 }
1920 
1921 static int target_write_prot_action(struct se_cmd *cmd)
1922 {
1923 	u32 sectors;
1924 	/*
1925 	 * Perform WRITE_INSERT of PI using software emulation when backend
1926 	 * device has PI enabled, if the transport has not already generated
1927 	 * PI using hardware WRITE_INSERT offload.
1928 	 */
1929 	switch (cmd->prot_op) {
1930 	case TARGET_PROT_DOUT_INSERT:
1931 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1932 			sbc_dif_generate(cmd);
1933 		break;
1934 	case TARGET_PROT_DOUT_STRIP:
1935 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1936 			break;
1937 
1938 		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1939 		cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1940 					     sectors, 0, cmd->t_prot_sg, 0);
1941 		if (unlikely(cmd->pi_err)) {
1942 			spin_lock_irq(&cmd->t_state_lock);
1943 			cmd->transport_state &= ~CMD_T_SENT;
1944 			spin_unlock_irq(&cmd->t_state_lock);
1945 			transport_generic_request_failure(cmd, cmd->pi_err);
1946 			return -1;
1947 		}
1948 		break;
1949 	default:
1950 		break;
1951 	}
1952 
1953 	return 0;
1954 }
1955 
1956 static bool target_handle_task_attr(struct se_cmd *cmd)
1957 {
1958 	struct se_device *dev = cmd->se_dev;
1959 
1960 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1961 		return false;
1962 
1963 	cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1964 
1965 	/*
1966 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1967 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1968 	 */
1969 	switch (cmd->sam_task_attr) {
1970 	case TCM_HEAD_TAG:
1971 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1972 			 cmd->t_task_cdb[0]);
1973 		return false;
1974 	case TCM_ORDERED_TAG:
1975 		atomic_inc_mb(&dev->dev_ordered_sync);
1976 
1977 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1978 			 cmd->t_task_cdb[0]);
1979 
1980 		/*
1981 		 * Execute an ORDERED command if no other older commands
1982 		 * exist that need to be completed first.
1983 		 */
1984 		if (!atomic_read(&dev->simple_cmds))
1985 			return false;
1986 		break;
1987 	default:
1988 		/*
1989 		 * For SIMPLE and UNTAGGED Task Attribute commands
1990 		 */
1991 		atomic_inc_mb(&dev->simple_cmds);
1992 		break;
1993 	}
1994 
1995 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1996 		return false;
1997 
1998 	spin_lock(&dev->delayed_cmd_lock);
1999 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
2000 	spin_unlock(&dev->delayed_cmd_lock);
2001 
2002 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
2003 		cmd->t_task_cdb[0], cmd->sam_task_attr);
2004 	return true;
2005 }
2006 
2007 static int __transport_check_aborted_status(struct se_cmd *, int);
2008 
2009 void target_execute_cmd(struct se_cmd *cmd)
2010 {
2011 	/*
2012 	 * Determine if frontend context caller is requesting the stopping of
2013 	 * this command for frontend exceptions.
2014 	 *
2015 	 * If the received CDB has aleady been aborted stop processing it here.
2016 	 */
2017 	spin_lock_irq(&cmd->t_state_lock);
2018 	if (__transport_check_aborted_status(cmd, 1)) {
2019 		spin_unlock_irq(&cmd->t_state_lock);
2020 		return;
2021 	}
2022 	if (cmd->transport_state & CMD_T_STOP) {
2023 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2024 			__func__, __LINE__, cmd->tag);
2025 
2026 		spin_unlock_irq(&cmd->t_state_lock);
2027 		complete_all(&cmd->t_transport_stop_comp);
2028 		return;
2029 	}
2030 
2031 	cmd->t_state = TRANSPORT_PROCESSING;
2032 	cmd->transport_state &= ~CMD_T_PRE_EXECUTE;
2033 	cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
2034 	spin_unlock_irq(&cmd->t_state_lock);
2035 
2036 	if (target_write_prot_action(cmd))
2037 		return;
2038 
2039 	if (target_handle_task_attr(cmd)) {
2040 		spin_lock_irq(&cmd->t_state_lock);
2041 		cmd->transport_state &= ~CMD_T_SENT;
2042 		spin_unlock_irq(&cmd->t_state_lock);
2043 		return;
2044 	}
2045 
2046 	__target_execute_cmd(cmd, true);
2047 }
2048 EXPORT_SYMBOL(target_execute_cmd);
2049 
2050 /*
2051  * Process all commands up to the last received ORDERED task attribute which
2052  * requires another blocking boundary
2053  */
2054 static void target_restart_delayed_cmds(struct se_device *dev)
2055 {
2056 	for (;;) {
2057 		struct se_cmd *cmd;
2058 
2059 		spin_lock(&dev->delayed_cmd_lock);
2060 		if (list_empty(&dev->delayed_cmd_list)) {
2061 			spin_unlock(&dev->delayed_cmd_lock);
2062 			break;
2063 		}
2064 
2065 		cmd = list_entry(dev->delayed_cmd_list.next,
2066 				 struct se_cmd, se_delayed_node);
2067 		list_del(&cmd->se_delayed_node);
2068 		spin_unlock(&dev->delayed_cmd_lock);
2069 
2070 		cmd->transport_state |= CMD_T_SENT;
2071 
2072 		__target_execute_cmd(cmd, true);
2073 
2074 		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
2075 			break;
2076 	}
2077 }
2078 
2079 /*
2080  * Called from I/O completion to determine which dormant/delayed
2081  * and ordered cmds need to have their tasks added to the execution queue.
2082  */
2083 static void transport_complete_task_attr(struct se_cmd *cmd)
2084 {
2085 	struct se_device *dev = cmd->se_dev;
2086 
2087 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2088 		return;
2089 
2090 	if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2091 		goto restart;
2092 
2093 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2094 		atomic_dec_mb(&dev->simple_cmds);
2095 		dev->dev_cur_ordered_id++;
2096 	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2097 		dev->dev_cur_ordered_id++;
2098 		pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2099 			 dev->dev_cur_ordered_id);
2100 	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2101 		atomic_dec_mb(&dev->dev_ordered_sync);
2102 
2103 		dev->dev_cur_ordered_id++;
2104 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2105 			 dev->dev_cur_ordered_id);
2106 	}
2107 	cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2108 
2109 restart:
2110 	target_restart_delayed_cmds(dev);
2111 }
2112 
2113 static void transport_complete_qf(struct se_cmd *cmd)
2114 {
2115 	int ret = 0;
2116 
2117 	transport_complete_task_attr(cmd);
2118 	/*
2119 	 * If a fabric driver ->write_pending() or ->queue_data_in() callback
2120 	 * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2121 	 * the same callbacks should not be retried.  Return CHECK_CONDITION
2122 	 * if a scsi_status is not already set.
2123 	 *
2124 	 * If a fabric driver ->queue_status() has returned non zero, always
2125 	 * keep retrying no matter what..
2126 	 */
2127 	if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2128 		if (cmd->scsi_status)
2129 			goto queue_status;
2130 
2131 		translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2132 		goto queue_status;
2133 	}
2134 
2135 	/*
2136 	 * Check if we need to send a sense buffer from
2137 	 * the struct se_cmd in question. We do NOT want
2138 	 * to take this path of the IO has been marked as
2139 	 * needing to be treated like a "normal read". This
2140 	 * is the case if it's a tape read, and either the
2141 	 * FM, EOM, or ILI bits are set, but there is no
2142 	 * sense data.
2143 	 */
2144 	if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2145 	    cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2146 		goto queue_status;
2147 
2148 	switch (cmd->data_direction) {
2149 	case DMA_FROM_DEVICE:
2150 		/* queue status if not treating this as a normal read */
2151 		if (cmd->scsi_status &&
2152 		    !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2153 			goto queue_status;
2154 
2155 		trace_target_cmd_complete(cmd);
2156 		ret = cmd->se_tfo->queue_data_in(cmd);
2157 		break;
2158 	case DMA_TO_DEVICE:
2159 		if (cmd->se_cmd_flags & SCF_BIDI) {
2160 			ret = cmd->se_tfo->queue_data_in(cmd);
2161 			break;
2162 		}
2163 		/* fall through */
2164 	case DMA_NONE:
2165 queue_status:
2166 		trace_target_cmd_complete(cmd);
2167 		ret = cmd->se_tfo->queue_status(cmd);
2168 		break;
2169 	default:
2170 		break;
2171 	}
2172 
2173 	if (ret < 0) {
2174 		transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2175 		return;
2176 	}
2177 	transport_lun_remove_cmd(cmd);
2178 	transport_cmd_check_stop_to_fabric(cmd);
2179 }
2180 
2181 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2182 					int err, bool write_pending)
2183 {
2184 	/*
2185 	 * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2186 	 * ->queue_data_in() callbacks from new process context.
2187 	 *
2188 	 * Otherwise for other errors, transport_complete_qf() will send
2189 	 * CHECK_CONDITION via ->queue_status() instead of attempting to
2190 	 * retry associated fabric driver data-transfer callbacks.
2191 	 */
2192 	if (err == -EAGAIN || err == -ENOMEM) {
2193 		cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2194 						 TRANSPORT_COMPLETE_QF_OK;
2195 	} else {
2196 		pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2197 		cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2198 	}
2199 
2200 	spin_lock_irq(&dev->qf_cmd_lock);
2201 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2202 	atomic_inc_mb(&dev->dev_qf_count);
2203 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2204 
2205 	schedule_work(&cmd->se_dev->qf_work_queue);
2206 }
2207 
2208 static bool target_read_prot_action(struct se_cmd *cmd)
2209 {
2210 	switch (cmd->prot_op) {
2211 	case TARGET_PROT_DIN_STRIP:
2212 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2213 			u32 sectors = cmd->data_length >>
2214 				  ilog2(cmd->se_dev->dev_attrib.block_size);
2215 
2216 			cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2217 						     sectors, 0, cmd->t_prot_sg,
2218 						     0);
2219 			if (cmd->pi_err)
2220 				return true;
2221 		}
2222 		break;
2223 	case TARGET_PROT_DIN_INSERT:
2224 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2225 			break;
2226 
2227 		sbc_dif_generate(cmd);
2228 		break;
2229 	default:
2230 		break;
2231 	}
2232 
2233 	return false;
2234 }
2235 
2236 static void target_complete_ok_work(struct work_struct *work)
2237 {
2238 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2239 	int ret;
2240 
2241 	/*
2242 	 * Check if we need to move delayed/dormant tasks from cmds on the
2243 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2244 	 * Attribute.
2245 	 */
2246 	transport_complete_task_attr(cmd);
2247 
2248 	/*
2249 	 * Check to schedule QUEUE_FULL work, or execute an existing
2250 	 * cmd->transport_qf_callback()
2251 	 */
2252 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2253 		schedule_work(&cmd->se_dev->qf_work_queue);
2254 
2255 	/*
2256 	 * Check if we need to send a sense buffer from
2257 	 * the struct se_cmd in question. We do NOT want
2258 	 * to take this path of the IO has been marked as
2259 	 * needing to be treated like a "normal read". This
2260 	 * is the case if it's a tape read, and either the
2261 	 * FM, EOM, or ILI bits are set, but there is no
2262 	 * sense data.
2263 	 */
2264 	if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2265 	    cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2266 		WARN_ON(!cmd->scsi_status);
2267 		ret = transport_send_check_condition_and_sense(
2268 					cmd, 0, 1);
2269 		if (ret)
2270 			goto queue_full;
2271 
2272 		transport_lun_remove_cmd(cmd);
2273 		transport_cmd_check_stop_to_fabric(cmd);
2274 		return;
2275 	}
2276 	/*
2277 	 * Check for a callback, used by amongst other things
2278 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2279 	 */
2280 	if (cmd->transport_complete_callback) {
2281 		sense_reason_t rc;
2282 		bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2283 		bool zero_dl = !(cmd->data_length);
2284 		int post_ret = 0;
2285 
2286 		rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2287 		if (!rc && !post_ret) {
2288 			if (caw && zero_dl)
2289 				goto queue_rsp;
2290 
2291 			return;
2292 		} else if (rc) {
2293 			ret = transport_send_check_condition_and_sense(cmd,
2294 						rc, 0);
2295 			if (ret)
2296 				goto queue_full;
2297 
2298 			transport_lun_remove_cmd(cmd);
2299 			transport_cmd_check_stop_to_fabric(cmd);
2300 			return;
2301 		}
2302 	}
2303 
2304 queue_rsp:
2305 	switch (cmd->data_direction) {
2306 	case DMA_FROM_DEVICE:
2307 		/*
2308 		 * if this is a READ-type IO, but SCSI status
2309 		 * is set, then skip returning data and just
2310 		 * return the status -- unless this IO is marked
2311 		 * as needing to be treated as a normal read,
2312 		 * in which case we want to go ahead and return
2313 		 * the data. This happens, for example, for tape
2314 		 * reads with the FM, EOM, or ILI bits set, with
2315 		 * no sense data.
2316 		 */
2317 		if (cmd->scsi_status &&
2318 		    !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2319 			goto queue_status;
2320 
2321 		atomic_long_add(cmd->data_length,
2322 				&cmd->se_lun->lun_stats.tx_data_octets);
2323 		/*
2324 		 * Perform READ_STRIP of PI using software emulation when
2325 		 * backend had PI enabled, if the transport will not be
2326 		 * performing hardware READ_STRIP offload.
2327 		 */
2328 		if (target_read_prot_action(cmd)) {
2329 			ret = transport_send_check_condition_and_sense(cmd,
2330 						cmd->pi_err, 0);
2331 			if (ret)
2332 				goto queue_full;
2333 
2334 			transport_lun_remove_cmd(cmd);
2335 			transport_cmd_check_stop_to_fabric(cmd);
2336 			return;
2337 		}
2338 
2339 		trace_target_cmd_complete(cmd);
2340 		ret = cmd->se_tfo->queue_data_in(cmd);
2341 		if (ret)
2342 			goto queue_full;
2343 		break;
2344 	case DMA_TO_DEVICE:
2345 		atomic_long_add(cmd->data_length,
2346 				&cmd->se_lun->lun_stats.rx_data_octets);
2347 		/*
2348 		 * Check if we need to send READ payload for BIDI-COMMAND
2349 		 */
2350 		if (cmd->se_cmd_flags & SCF_BIDI) {
2351 			atomic_long_add(cmd->data_length,
2352 					&cmd->se_lun->lun_stats.tx_data_octets);
2353 			ret = cmd->se_tfo->queue_data_in(cmd);
2354 			if (ret)
2355 				goto queue_full;
2356 			break;
2357 		}
2358 		/* fall through */
2359 	case DMA_NONE:
2360 queue_status:
2361 		trace_target_cmd_complete(cmd);
2362 		ret = cmd->se_tfo->queue_status(cmd);
2363 		if (ret)
2364 			goto queue_full;
2365 		break;
2366 	default:
2367 		break;
2368 	}
2369 
2370 	transport_lun_remove_cmd(cmd);
2371 	transport_cmd_check_stop_to_fabric(cmd);
2372 	return;
2373 
2374 queue_full:
2375 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2376 		" data_direction: %d\n", cmd, cmd->data_direction);
2377 
2378 	transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2379 }
2380 
2381 void target_free_sgl(struct scatterlist *sgl, int nents)
2382 {
2383 	sgl_free_n_order(sgl, nents, 0);
2384 }
2385 EXPORT_SYMBOL(target_free_sgl);
2386 
2387 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2388 {
2389 	/*
2390 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2391 	 * emulation, and free + reset pointers if necessary..
2392 	 */
2393 	if (!cmd->t_data_sg_orig)
2394 		return;
2395 
2396 	kfree(cmd->t_data_sg);
2397 	cmd->t_data_sg = cmd->t_data_sg_orig;
2398 	cmd->t_data_sg_orig = NULL;
2399 	cmd->t_data_nents = cmd->t_data_nents_orig;
2400 	cmd->t_data_nents_orig = 0;
2401 }
2402 
2403 static inline void transport_free_pages(struct se_cmd *cmd)
2404 {
2405 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2406 		target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2407 		cmd->t_prot_sg = NULL;
2408 		cmd->t_prot_nents = 0;
2409 	}
2410 
2411 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2412 		/*
2413 		 * Release special case READ buffer payload required for
2414 		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2415 		 */
2416 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2417 			target_free_sgl(cmd->t_bidi_data_sg,
2418 					   cmd->t_bidi_data_nents);
2419 			cmd->t_bidi_data_sg = NULL;
2420 			cmd->t_bidi_data_nents = 0;
2421 		}
2422 		transport_reset_sgl_orig(cmd);
2423 		return;
2424 	}
2425 	transport_reset_sgl_orig(cmd);
2426 
2427 	target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2428 	cmd->t_data_sg = NULL;
2429 	cmd->t_data_nents = 0;
2430 
2431 	target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2432 	cmd->t_bidi_data_sg = NULL;
2433 	cmd->t_bidi_data_nents = 0;
2434 }
2435 
2436 void *transport_kmap_data_sg(struct se_cmd *cmd)
2437 {
2438 	struct scatterlist *sg = cmd->t_data_sg;
2439 	struct page **pages;
2440 	int i;
2441 
2442 	/*
2443 	 * We need to take into account a possible offset here for fabrics like
2444 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2445 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2446 	 */
2447 	if (!cmd->t_data_nents)
2448 		return NULL;
2449 
2450 	BUG_ON(!sg);
2451 	if (cmd->t_data_nents == 1)
2452 		return kmap(sg_page(sg)) + sg->offset;
2453 
2454 	/* >1 page. use vmap */
2455 	pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2456 	if (!pages)
2457 		return NULL;
2458 
2459 	/* convert sg[] to pages[] */
2460 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2461 		pages[i] = sg_page(sg);
2462 	}
2463 
2464 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2465 	kfree(pages);
2466 	if (!cmd->t_data_vmap)
2467 		return NULL;
2468 
2469 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2470 }
2471 EXPORT_SYMBOL(transport_kmap_data_sg);
2472 
2473 void transport_kunmap_data_sg(struct se_cmd *cmd)
2474 {
2475 	if (!cmd->t_data_nents) {
2476 		return;
2477 	} else if (cmd->t_data_nents == 1) {
2478 		kunmap(sg_page(cmd->t_data_sg));
2479 		return;
2480 	}
2481 
2482 	vunmap(cmd->t_data_vmap);
2483 	cmd->t_data_vmap = NULL;
2484 }
2485 EXPORT_SYMBOL(transport_kunmap_data_sg);
2486 
2487 int
2488 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2489 		 bool zero_page, bool chainable)
2490 {
2491 	gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
2492 
2493 	*sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
2494 	return *sgl ? 0 : -ENOMEM;
2495 }
2496 EXPORT_SYMBOL(target_alloc_sgl);
2497 
2498 /*
2499  * Allocate any required resources to execute the command.  For writes we
2500  * might not have the payload yet, so notify the fabric via a call to
2501  * ->write_pending instead. Otherwise place it on the execution queue.
2502  */
2503 sense_reason_t
2504 transport_generic_new_cmd(struct se_cmd *cmd)
2505 {
2506 	unsigned long flags;
2507 	int ret = 0;
2508 	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2509 
2510 	if (cmd->prot_op != TARGET_PROT_NORMAL &&
2511 	    !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2512 		ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2513 				       cmd->prot_length, true, false);
2514 		if (ret < 0)
2515 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2516 	}
2517 
2518 	/*
2519 	 * Determine is the TCM fabric module has already allocated physical
2520 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2521 	 * beforehand.
2522 	 */
2523 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2524 	    cmd->data_length) {
2525 
2526 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2527 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2528 			u32 bidi_length;
2529 
2530 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2531 				bidi_length = cmd->t_task_nolb *
2532 					      cmd->se_dev->dev_attrib.block_size;
2533 			else
2534 				bidi_length = cmd->data_length;
2535 
2536 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2537 					       &cmd->t_bidi_data_nents,
2538 					       bidi_length, zero_flag, false);
2539 			if (ret < 0)
2540 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2541 		}
2542 
2543 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2544 				       cmd->data_length, zero_flag, false);
2545 		if (ret < 0)
2546 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2547 	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2548 		    cmd->data_length) {
2549 		/*
2550 		 * Special case for COMPARE_AND_WRITE with fabrics
2551 		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2552 		 */
2553 		u32 caw_length = cmd->t_task_nolb *
2554 				 cmd->se_dev->dev_attrib.block_size;
2555 
2556 		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2557 				       &cmd->t_bidi_data_nents,
2558 				       caw_length, zero_flag, false);
2559 		if (ret < 0)
2560 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2561 	}
2562 	/*
2563 	 * If this command is not a write we can execute it right here,
2564 	 * for write buffers we need to notify the fabric driver first
2565 	 * and let it call back once the write buffers are ready.
2566 	 */
2567 	target_add_to_state_list(cmd);
2568 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2569 		target_execute_cmd(cmd);
2570 		return 0;
2571 	}
2572 
2573 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2574 	cmd->t_state = TRANSPORT_WRITE_PENDING;
2575 	/*
2576 	 * Determine if frontend context caller is requesting the stopping of
2577 	 * this command for frontend exceptions.
2578 	 */
2579 	if (cmd->transport_state & CMD_T_STOP) {
2580 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2581 			 __func__, __LINE__, cmd->tag);
2582 
2583 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2584 
2585 		complete_all(&cmd->t_transport_stop_comp);
2586 		return 0;
2587 	}
2588 	cmd->transport_state &= ~CMD_T_ACTIVE;
2589 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2590 
2591 	ret = cmd->se_tfo->write_pending(cmd);
2592 	if (ret)
2593 		goto queue_full;
2594 
2595 	return 0;
2596 
2597 queue_full:
2598 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2599 	transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2600 	return 0;
2601 }
2602 EXPORT_SYMBOL(transport_generic_new_cmd);
2603 
2604 static void transport_write_pending_qf(struct se_cmd *cmd)
2605 {
2606 	unsigned long flags;
2607 	int ret;
2608 	bool stop;
2609 
2610 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2611 	stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2612 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2613 
2614 	if (stop) {
2615 		pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2616 			__func__, __LINE__, cmd->tag);
2617 		complete_all(&cmd->t_transport_stop_comp);
2618 		return;
2619 	}
2620 
2621 	ret = cmd->se_tfo->write_pending(cmd);
2622 	if (ret) {
2623 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2624 			 cmd);
2625 		transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2626 	}
2627 }
2628 
2629 static bool
2630 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2631 			   unsigned long *flags);
2632 
2633 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2634 {
2635 	unsigned long flags;
2636 
2637 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2638 	__transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2639 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2640 }
2641 
2642 /*
2643  * This function is called by frontend drivers after processing of a command
2644  * has finished.
2645  *
2646  * The protocol for ensuring that either the regular flow or the TMF
2647  * code drops one reference is as follows:
2648  * - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
2649  *   the frontend driver to drop one reference, synchronously or asynchronously.
2650  * - During regular command processing the target core sets CMD_T_COMPLETE
2651  *   before invoking one of the .queue_*() functions.
2652  * - The code that aborts commands skips commands and TMFs for which
2653  *   CMD_T_COMPLETE has been set.
2654  * - CMD_T_ABORTED is set atomically after the CMD_T_COMPLETE check for
2655  *   commands that will be aborted.
2656  * - If the CMD_T_ABORTED flag is set but CMD_T_TAS has not been set
2657  *   transport_generic_free_cmd() skips its call to target_put_sess_cmd().
2658  * - For aborted commands for which CMD_T_TAS has been set .queue_status() will
2659  *   be called and will drop a reference.
2660  * - For aborted commands for which CMD_T_TAS has not been set .aborted_task()
2661  *   will be called. transport_cmd_finish_abort() will drop the final reference.
2662  */
2663 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2664 {
2665 	DECLARE_COMPLETION_ONSTACK(compl);
2666 	int ret = 0;
2667 	bool aborted = false, tas = false;
2668 
2669 	if (wait_for_tasks)
2670 		target_wait_free_cmd(cmd, &aborted, &tas);
2671 
2672 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD) {
2673 		/*
2674 		 * Handle WRITE failure case where transport_generic_new_cmd()
2675 		 * has already added se_cmd to state_list, but fabric has
2676 		 * failed command before I/O submission.
2677 		 */
2678 		if (cmd->state_active)
2679 			target_remove_from_state_list(cmd);
2680 
2681 		if (cmd->se_lun)
2682 			transport_lun_remove_cmd(cmd);
2683 	}
2684 	if (aborted)
2685 		cmd->compl = &compl;
2686 	if (!aborted || tas)
2687 		ret = target_put_sess_cmd(cmd);
2688 	if (aborted) {
2689 		pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2690 		wait_for_completion(&compl);
2691 		ret = 1;
2692 	}
2693 	return ret;
2694 }
2695 EXPORT_SYMBOL(transport_generic_free_cmd);
2696 
2697 /**
2698  * target_get_sess_cmd - Add command to active ->sess_cmd_list
2699  * @se_cmd:	command descriptor to add
2700  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2701  */
2702 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2703 {
2704 	struct se_session *se_sess = se_cmd->se_sess;
2705 	unsigned long flags;
2706 	int ret = 0;
2707 
2708 	/*
2709 	 * Add a second kref if the fabric caller is expecting to handle
2710 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2711 	 * invocations before se_cmd descriptor release.
2712 	 */
2713 	if (ack_kref) {
2714 		if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2715 			return -EINVAL;
2716 
2717 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2718 	}
2719 
2720 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2721 	if (se_sess->sess_tearing_down) {
2722 		ret = -ESHUTDOWN;
2723 		goto out;
2724 	}
2725 	se_cmd->transport_state |= CMD_T_PRE_EXECUTE;
2726 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2727 out:
2728 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2729 
2730 	if (ret && ack_kref)
2731 		target_put_sess_cmd(se_cmd);
2732 
2733 	return ret;
2734 }
2735 EXPORT_SYMBOL(target_get_sess_cmd);
2736 
2737 static void target_free_cmd_mem(struct se_cmd *cmd)
2738 {
2739 	transport_free_pages(cmd);
2740 
2741 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2742 		core_tmr_release_req(cmd->se_tmr_req);
2743 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2744 		kfree(cmd->t_task_cdb);
2745 }
2746 
2747 static void target_release_cmd_kref(struct kref *kref)
2748 {
2749 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2750 	struct se_session *se_sess = se_cmd->se_sess;
2751 	struct completion *compl = se_cmd->compl;
2752 	unsigned long flags;
2753 
2754 	if (se_sess) {
2755 		spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2756 		list_del_init(&se_cmd->se_cmd_list);
2757 		if (list_empty(&se_sess->sess_cmd_list))
2758 			wake_up(&se_sess->cmd_list_wq);
2759 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2760 	}
2761 
2762 	target_free_cmd_mem(se_cmd);
2763 	se_cmd->se_tfo->release_cmd(se_cmd);
2764 	if (compl)
2765 		complete(compl);
2766 }
2767 
2768 /**
2769  * target_put_sess_cmd - decrease the command reference count
2770  * @se_cmd:	command to drop a reference from
2771  *
2772  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2773  * refcount to drop to zero. Returns zero otherwise.
2774  */
2775 int target_put_sess_cmd(struct se_cmd *se_cmd)
2776 {
2777 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2778 }
2779 EXPORT_SYMBOL(target_put_sess_cmd);
2780 
2781 static const char *data_dir_name(enum dma_data_direction d)
2782 {
2783 	switch (d) {
2784 	case DMA_BIDIRECTIONAL:	return "BIDI";
2785 	case DMA_TO_DEVICE:	return "WRITE";
2786 	case DMA_FROM_DEVICE:	return "READ";
2787 	case DMA_NONE:		return "NONE";
2788 	}
2789 
2790 	return "(?)";
2791 }
2792 
2793 static const char *cmd_state_name(enum transport_state_table t)
2794 {
2795 	switch (t) {
2796 	case TRANSPORT_NO_STATE:	return "NO_STATE";
2797 	case TRANSPORT_NEW_CMD:		return "NEW_CMD";
2798 	case TRANSPORT_WRITE_PENDING:	return "WRITE_PENDING";
2799 	case TRANSPORT_PROCESSING:	return "PROCESSING";
2800 	case TRANSPORT_COMPLETE:	return "COMPLETE";
2801 	case TRANSPORT_ISTATE_PROCESSING:
2802 					return "ISTATE_PROCESSING";
2803 	case TRANSPORT_COMPLETE_QF_WP:	return "COMPLETE_QF_WP";
2804 	case TRANSPORT_COMPLETE_QF_OK:	return "COMPLETE_QF_OK";
2805 	case TRANSPORT_COMPLETE_QF_ERR:	return "COMPLETE_QF_ERR";
2806 	}
2807 
2808 	return "(?)";
2809 }
2810 
2811 static void target_append_str(char **str, const char *txt)
2812 {
2813 	char *prev = *str;
2814 
2815 	*str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
2816 		kstrdup(txt, GFP_ATOMIC);
2817 	kfree(prev);
2818 }
2819 
2820 /*
2821  * Convert a transport state bitmask into a string. The caller is
2822  * responsible for freeing the returned pointer.
2823  */
2824 static char *target_ts_to_str(u32 ts)
2825 {
2826 	char *str = NULL;
2827 
2828 	if (ts & CMD_T_ABORTED)
2829 		target_append_str(&str, "aborted");
2830 	if (ts & CMD_T_ACTIVE)
2831 		target_append_str(&str, "active");
2832 	if (ts & CMD_T_COMPLETE)
2833 		target_append_str(&str, "complete");
2834 	if (ts & CMD_T_SENT)
2835 		target_append_str(&str, "sent");
2836 	if (ts & CMD_T_STOP)
2837 		target_append_str(&str, "stop");
2838 	if (ts & CMD_T_FABRIC_STOP)
2839 		target_append_str(&str, "fabric_stop");
2840 
2841 	return str;
2842 }
2843 
2844 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
2845 {
2846 	switch (tmf) {
2847 	case TMR_ABORT_TASK:		return "ABORT_TASK";
2848 	case TMR_ABORT_TASK_SET:	return "ABORT_TASK_SET";
2849 	case TMR_CLEAR_ACA:		return "CLEAR_ACA";
2850 	case TMR_CLEAR_TASK_SET:	return "CLEAR_TASK_SET";
2851 	case TMR_LUN_RESET:		return "LUN_RESET";
2852 	case TMR_TARGET_WARM_RESET:	return "TARGET_WARM_RESET";
2853 	case TMR_TARGET_COLD_RESET:	return "TARGET_COLD_RESET";
2854 	case TMR_UNKNOWN:		break;
2855 	}
2856 	return "(?)";
2857 }
2858 
2859 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
2860 {
2861 	char *ts_str = target_ts_to_str(cmd->transport_state);
2862 	const u8 *cdb = cmd->t_task_cdb;
2863 	struct se_tmr_req *tmf = cmd->se_tmr_req;
2864 
2865 	if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2866 		pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
2867 			 pfx, cdb[0], cdb[1], cmd->tag,
2868 			 data_dir_name(cmd->data_direction),
2869 			 cmd->se_tfo->get_cmd_state(cmd),
2870 			 cmd_state_name(cmd->t_state), cmd->data_length,
2871 			 kref_read(&cmd->cmd_kref), ts_str);
2872 	} else {
2873 		pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
2874 			 pfx, target_tmf_name(tmf->function), cmd->tag,
2875 			 tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
2876 			 cmd_state_name(cmd->t_state),
2877 			 kref_read(&cmd->cmd_kref), ts_str);
2878 	}
2879 	kfree(ts_str);
2880 }
2881 EXPORT_SYMBOL(target_show_cmd);
2882 
2883 /**
2884  * target_sess_cmd_list_set_waiting - Set sess_tearing_down so no new commands are queued.
2885  * @se_sess:	session to flag
2886  */
2887 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2888 {
2889 	unsigned long flags;
2890 
2891 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2892 	se_sess->sess_tearing_down = 1;
2893 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2894 }
2895 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2896 
2897 /**
2898  * target_wait_for_sess_cmds - Wait for outstanding commands
2899  * @se_sess:    session to wait for active I/O
2900  */
2901 void target_wait_for_sess_cmds(struct se_session *se_sess)
2902 {
2903 	struct se_cmd *cmd;
2904 	int ret;
2905 
2906 	WARN_ON_ONCE(!se_sess->sess_tearing_down);
2907 
2908 	spin_lock_irq(&se_sess->sess_cmd_lock);
2909 	do {
2910 		ret = wait_event_interruptible_lock_irq_timeout(
2911 				se_sess->cmd_list_wq,
2912 				list_empty(&se_sess->sess_cmd_list),
2913 				se_sess->sess_cmd_lock, 180 * HZ);
2914 		list_for_each_entry(cmd, &se_sess->sess_cmd_list, se_cmd_list)
2915 			target_show_cmd("session shutdown: still waiting for ",
2916 					cmd);
2917 	} while (ret <= 0);
2918 	spin_unlock_irq(&se_sess->sess_cmd_lock);
2919 }
2920 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2921 
2922 static void target_lun_confirm(struct percpu_ref *ref)
2923 {
2924 	struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2925 
2926 	complete(&lun->lun_ref_comp);
2927 }
2928 
2929 void transport_clear_lun_ref(struct se_lun *lun)
2930 {
2931 	/*
2932 	 * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2933 	 * the initial reference and schedule confirm kill to be
2934 	 * executed after one full RCU grace period has completed.
2935 	 */
2936 	percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2937 	/*
2938 	 * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2939 	 * to call target_lun_confirm after lun->lun_ref has been marked
2940 	 * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2941 	 * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2942 	 * fails for all new incoming I/O.
2943 	 */
2944 	wait_for_completion(&lun->lun_ref_comp);
2945 	/*
2946 	 * The second completion waits for percpu_ref_put_many() to
2947 	 * invoke ->release() after lun->lun_ref has switched to
2948 	 * atomic_t mode, and lun->lun_ref.count has reached zero.
2949 	 *
2950 	 * At this point all target-core lun->lun_ref references have
2951 	 * been dropped via transport_lun_remove_cmd(), and it's safe
2952 	 * to proceed with the remaining LUN shutdown.
2953 	 */
2954 	wait_for_completion(&lun->lun_shutdown_comp);
2955 }
2956 
2957 static bool
2958 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2959 			   bool *aborted, bool *tas, unsigned long *flags)
2960 	__releases(&cmd->t_state_lock)
2961 	__acquires(&cmd->t_state_lock)
2962 {
2963 
2964 	assert_spin_locked(&cmd->t_state_lock);
2965 	WARN_ON_ONCE(!irqs_disabled());
2966 
2967 	if (fabric_stop)
2968 		cmd->transport_state |= CMD_T_FABRIC_STOP;
2969 
2970 	if (cmd->transport_state & CMD_T_ABORTED)
2971 		*aborted = true;
2972 
2973 	if (cmd->transport_state & CMD_T_TAS)
2974 		*tas = true;
2975 
2976 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2977 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2978 		return false;
2979 
2980 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2981 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2982 		return false;
2983 
2984 	if (!(cmd->transport_state & CMD_T_ACTIVE))
2985 		return false;
2986 
2987 	if (fabric_stop && *aborted)
2988 		return false;
2989 
2990 	cmd->transport_state |= CMD_T_STOP;
2991 
2992 	target_show_cmd("wait_for_tasks: Stopping ", cmd);
2993 
2994 	spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2995 
2996 	while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
2997 					    180 * HZ))
2998 		target_show_cmd("wait for tasks: ", cmd);
2999 
3000 	spin_lock_irqsave(&cmd->t_state_lock, *flags);
3001 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
3002 
3003 	pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
3004 		 "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
3005 
3006 	return true;
3007 }
3008 
3009 /**
3010  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3011  * @cmd: command to wait on
3012  */
3013 bool transport_wait_for_tasks(struct se_cmd *cmd)
3014 {
3015 	unsigned long flags;
3016 	bool ret, aborted = false, tas = false;
3017 
3018 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3019 	ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3020 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3021 
3022 	return ret;
3023 }
3024 EXPORT_SYMBOL(transport_wait_for_tasks);
3025 
3026 struct sense_info {
3027 	u8 key;
3028 	u8 asc;
3029 	u8 ascq;
3030 	bool add_sector_info;
3031 };
3032 
3033 static const struct sense_info sense_info_table[] = {
3034 	[TCM_NO_SENSE] = {
3035 		.key = NOT_READY
3036 	},
3037 	[TCM_NON_EXISTENT_LUN] = {
3038 		.key = ILLEGAL_REQUEST,
3039 		.asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3040 	},
3041 	[TCM_UNSUPPORTED_SCSI_OPCODE] = {
3042 		.key = ILLEGAL_REQUEST,
3043 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3044 	},
3045 	[TCM_SECTOR_COUNT_TOO_MANY] = {
3046 		.key = ILLEGAL_REQUEST,
3047 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3048 	},
3049 	[TCM_UNKNOWN_MODE_PAGE] = {
3050 		.key = ILLEGAL_REQUEST,
3051 		.asc = 0x24, /* INVALID FIELD IN CDB */
3052 	},
3053 	[TCM_CHECK_CONDITION_ABORT_CMD] = {
3054 		.key = ABORTED_COMMAND,
3055 		.asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3056 		.ascq = 0x03,
3057 	},
3058 	[TCM_INCORRECT_AMOUNT_OF_DATA] = {
3059 		.key = ABORTED_COMMAND,
3060 		.asc = 0x0c, /* WRITE ERROR */
3061 		.ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3062 	},
3063 	[TCM_INVALID_CDB_FIELD] = {
3064 		.key = ILLEGAL_REQUEST,
3065 		.asc = 0x24, /* INVALID FIELD IN CDB */
3066 	},
3067 	[TCM_INVALID_PARAMETER_LIST] = {
3068 		.key = ILLEGAL_REQUEST,
3069 		.asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3070 	},
3071 	[TCM_TOO_MANY_TARGET_DESCS] = {
3072 		.key = ILLEGAL_REQUEST,
3073 		.asc = 0x26,
3074 		.ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3075 	},
3076 	[TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3077 		.key = ILLEGAL_REQUEST,
3078 		.asc = 0x26,
3079 		.ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3080 	},
3081 	[TCM_TOO_MANY_SEGMENT_DESCS] = {
3082 		.key = ILLEGAL_REQUEST,
3083 		.asc = 0x26,
3084 		.ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3085 	},
3086 	[TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3087 		.key = ILLEGAL_REQUEST,
3088 		.asc = 0x26,
3089 		.ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3090 	},
3091 	[TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3092 		.key = ILLEGAL_REQUEST,
3093 		.asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3094 	},
3095 	[TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3096 		.key = ILLEGAL_REQUEST,
3097 		.asc = 0x0c, /* WRITE ERROR */
3098 		.ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3099 	},
3100 	[TCM_SERVICE_CRC_ERROR] = {
3101 		.key = ABORTED_COMMAND,
3102 		.asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3103 		.ascq = 0x05, /* N/A */
3104 	},
3105 	[TCM_SNACK_REJECTED] = {
3106 		.key = ABORTED_COMMAND,
3107 		.asc = 0x11, /* READ ERROR */
3108 		.ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3109 	},
3110 	[TCM_WRITE_PROTECTED] = {
3111 		.key = DATA_PROTECT,
3112 		.asc = 0x27, /* WRITE PROTECTED */
3113 	},
3114 	[TCM_ADDRESS_OUT_OF_RANGE] = {
3115 		.key = ILLEGAL_REQUEST,
3116 		.asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3117 	},
3118 	[TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3119 		.key = UNIT_ATTENTION,
3120 	},
3121 	[TCM_CHECK_CONDITION_NOT_READY] = {
3122 		.key = NOT_READY,
3123 	},
3124 	[TCM_MISCOMPARE_VERIFY] = {
3125 		.key = MISCOMPARE,
3126 		.asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3127 		.ascq = 0x00,
3128 	},
3129 	[TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3130 		.key = ABORTED_COMMAND,
3131 		.asc = 0x10,
3132 		.ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3133 		.add_sector_info = true,
3134 	},
3135 	[TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3136 		.key = ABORTED_COMMAND,
3137 		.asc = 0x10,
3138 		.ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3139 		.add_sector_info = true,
3140 	},
3141 	[TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3142 		.key = ABORTED_COMMAND,
3143 		.asc = 0x10,
3144 		.ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3145 		.add_sector_info = true,
3146 	},
3147 	[TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3148 		.key = COPY_ABORTED,
3149 		.asc = 0x0d,
3150 		.ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3151 
3152 	},
3153 	[TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3154 		/*
3155 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
3156 		 * Solaris initiators.  Returning NOT READY instead means the
3157 		 * operations will be retried a finite number of times and we
3158 		 * can survive intermittent errors.
3159 		 */
3160 		.key = NOT_READY,
3161 		.asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3162 	},
3163 	[TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3164 		/*
3165 		 * From spc4r22 section5.7.7,5.7.8
3166 		 * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3167 		 * or a REGISTER AND IGNORE EXISTING KEY service action or
3168 		 * REGISTER AND MOVE service actionis attempted,
3169 		 * but there are insufficient device server resources to complete the
3170 		 * operation, then the command shall be terminated with CHECK CONDITION
3171 		 * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3172 		 * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3173 		 */
3174 		.key = ILLEGAL_REQUEST,
3175 		.asc = 0x55,
3176 		.ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3177 	},
3178 };
3179 
3180 /**
3181  * translate_sense_reason - translate a sense reason into T10 key, asc and ascq
3182  * @cmd: SCSI command in which the resulting sense buffer or SCSI status will
3183  *   be stored.
3184  * @reason: LIO sense reason code. If this argument has the value
3185  *   TCM_CHECK_CONDITION_UNIT_ATTENTION, try to dequeue a unit attention. If
3186  *   dequeuing a unit attention fails due to multiple commands being processed
3187  *   concurrently, set the command status to BUSY.
3188  *
3189  * Return: 0 upon success or -EINVAL if the sense buffer is too small.
3190  */
3191 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3192 {
3193 	const struct sense_info *si;
3194 	u8 *buffer = cmd->sense_buffer;
3195 	int r = (__force int)reason;
3196 	u8 key, asc, ascq;
3197 	bool desc_format = target_sense_desc_format(cmd->se_dev);
3198 
3199 	if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
3200 		si = &sense_info_table[r];
3201 	else
3202 		si = &sense_info_table[(__force int)
3203 				       TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3204 
3205 	key = si->key;
3206 	if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3207 		if (!core_scsi3_ua_for_check_condition(cmd, &key, &asc,
3208 						       &ascq)) {
3209 			cmd->scsi_status = SAM_STAT_BUSY;
3210 			return;
3211 		}
3212 	} else if (si->asc == 0) {
3213 		WARN_ON_ONCE(cmd->scsi_asc == 0);
3214 		asc = cmd->scsi_asc;
3215 		ascq = cmd->scsi_ascq;
3216 	} else {
3217 		asc = si->asc;
3218 		ascq = si->ascq;
3219 	}
3220 
3221 	cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3222 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3223 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3224 	scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
3225 	if (si->add_sector_info)
3226 		WARN_ON_ONCE(scsi_set_sense_information(buffer,
3227 							cmd->scsi_sense_length,
3228 							cmd->bad_sector) < 0);
3229 }
3230 
3231 int
3232 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3233 		sense_reason_t reason, int from_transport)
3234 {
3235 	unsigned long flags;
3236 
3237 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3238 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3239 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3240 		return 0;
3241 	}
3242 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3243 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3244 
3245 	if (!from_transport)
3246 		translate_sense_reason(cmd, reason);
3247 
3248 	trace_target_cmd_complete(cmd);
3249 	return cmd->se_tfo->queue_status(cmd);
3250 }
3251 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3252 
3253 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3254 	__releases(&cmd->t_state_lock)
3255 	__acquires(&cmd->t_state_lock)
3256 {
3257 	int ret;
3258 
3259 	assert_spin_locked(&cmd->t_state_lock);
3260 	WARN_ON_ONCE(!irqs_disabled());
3261 
3262 	if (!(cmd->transport_state & CMD_T_ABORTED))
3263 		return 0;
3264 	/*
3265 	 * If cmd has been aborted but either no status is to be sent or it has
3266 	 * already been sent, just return
3267 	 */
3268 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3269 		if (send_status)
3270 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3271 		return 1;
3272 	}
3273 
3274 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3275 		" 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3276 
3277 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3278 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3279 	trace_target_cmd_complete(cmd);
3280 
3281 	spin_unlock_irq(&cmd->t_state_lock);
3282 	ret = cmd->se_tfo->queue_status(cmd);
3283 	if (ret)
3284 		transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3285 	spin_lock_irq(&cmd->t_state_lock);
3286 
3287 	return 1;
3288 }
3289 
3290 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3291 {
3292 	int ret;
3293 
3294 	spin_lock_irq(&cmd->t_state_lock);
3295 	ret = __transport_check_aborted_status(cmd, send_status);
3296 	spin_unlock_irq(&cmd->t_state_lock);
3297 
3298 	return ret;
3299 }
3300 EXPORT_SYMBOL(transport_check_aborted_status);
3301 
3302 void transport_send_task_abort(struct se_cmd *cmd)
3303 {
3304 	unsigned long flags;
3305 	int ret;
3306 
3307 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3308 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3309 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3310 		return;
3311 	}
3312 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3313 
3314 	/*
3315 	 * If there are still expected incoming fabric WRITEs, we wait
3316 	 * until until they have completed before sending a TASK_ABORTED
3317 	 * response.  This response with TASK_ABORTED status will be
3318 	 * queued back to fabric module by transport_check_aborted_status().
3319 	 */
3320 	if (cmd->data_direction == DMA_TO_DEVICE) {
3321 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3322 			spin_lock_irqsave(&cmd->t_state_lock, flags);
3323 			if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3324 				spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3325 				goto send_abort;
3326 			}
3327 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3328 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3329 			return;
3330 		}
3331 	}
3332 send_abort:
3333 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3334 
3335 	transport_lun_remove_cmd(cmd);
3336 
3337 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3338 		 cmd->t_task_cdb[0], cmd->tag);
3339 
3340 	trace_target_cmd_complete(cmd);
3341 	ret = cmd->se_tfo->queue_status(cmd);
3342 	if (ret)
3343 		transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3344 }
3345 
3346 static void target_tmr_work(struct work_struct *work)
3347 {
3348 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3349 	struct se_device *dev = cmd->se_dev;
3350 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3351 	unsigned long flags;
3352 	int ret;
3353 
3354 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3355 	if (cmd->transport_state & CMD_T_ABORTED) {
3356 		tmr->response = TMR_FUNCTION_REJECTED;
3357 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3358 		goto check_stop;
3359 	}
3360 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3361 
3362 	switch (tmr->function) {
3363 	case TMR_ABORT_TASK:
3364 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3365 		break;
3366 	case TMR_ABORT_TASK_SET:
3367 	case TMR_CLEAR_ACA:
3368 	case TMR_CLEAR_TASK_SET:
3369 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3370 		break;
3371 	case TMR_LUN_RESET:
3372 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3373 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3374 					 TMR_FUNCTION_REJECTED;
3375 		if (tmr->response == TMR_FUNCTION_COMPLETE) {
3376 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3377 					       cmd->orig_fe_lun, 0x29,
3378 					       ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3379 		}
3380 		break;
3381 	case TMR_TARGET_WARM_RESET:
3382 		tmr->response = TMR_FUNCTION_REJECTED;
3383 		break;
3384 	case TMR_TARGET_COLD_RESET:
3385 		tmr->response = TMR_FUNCTION_REJECTED;
3386 		break;
3387 	default:
3388 		pr_err("Unknown TMR function: 0x%02x.\n",
3389 				tmr->function);
3390 		tmr->response = TMR_FUNCTION_REJECTED;
3391 		break;
3392 	}
3393 
3394 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3395 	if (cmd->transport_state & CMD_T_ABORTED) {
3396 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3397 		goto check_stop;
3398 	}
3399 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3400 
3401 	cmd->se_tfo->queue_tm_rsp(cmd);
3402 
3403 check_stop:
3404 	transport_lun_remove_cmd(cmd);
3405 	transport_cmd_check_stop_to_fabric(cmd);
3406 }
3407 
3408 int transport_generic_handle_tmr(
3409 	struct se_cmd *cmd)
3410 {
3411 	unsigned long flags;
3412 	bool aborted = false;
3413 
3414 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3415 	if (cmd->transport_state & CMD_T_ABORTED) {
3416 		aborted = true;
3417 	} else {
3418 		cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3419 		cmd->transport_state |= CMD_T_ACTIVE;
3420 	}
3421 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3422 
3423 	if (aborted) {
3424 		pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3425 			"ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3426 			cmd->se_tmr_req->ref_task_tag, cmd->tag);
3427 		transport_lun_remove_cmd(cmd);
3428 		transport_cmd_check_stop_to_fabric(cmd);
3429 		return 0;
3430 	}
3431 
3432 	INIT_WORK(&cmd->work, target_tmr_work);
3433 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3434 	return 0;
3435 }
3436 EXPORT_SYMBOL(transport_generic_handle_tmr);
3437 
3438 bool
3439 target_check_wce(struct se_device *dev)
3440 {
3441 	bool wce = false;
3442 
3443 	if (dev->transport->get_write_cache)
3444 		wce = dev->transport->get_write_cache(dev);
3445 	else if (dev->dev_attrib.emulate_write_cache > 0)
3446 		wce = true;
3447 
3448 	return wce;
3449 }
3450 
3451 bool
3452 target_check_fua(struct se_device *dev)
3453 {
3454 	return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3455 }
3456