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