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	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
326	unsigned char buf[PR_REG_ISID_LEN];
327
328	se_sess->se_tpg = se_tpg;
329	se_sess->fabric_sess_ptr = fabric_sess_ptr;
330	/*
331	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
332	 *
333	 * Only set for struct se_session's that will actually be moving I/O.
334	 * eg: *NOT* discovery sessions.
335	 */
336	if (se_nacl) {
337		/*
338		 *
339		 * Determine if fabric allows for T10-PI feature bits exposed to
340		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
341		 *
342		 * If so, then always save prot_type on a per se_node_acl node
343		 * basis and re-instate the previous sess_prot_type to avoid
344		 * disabling PI from below any previously initiator side
345		 * registered LUNs.
346		 */
347		if (se_nacl->saved_prot_type)
348			se_sess->sess_prot_type = se_nacl->saved_prot_type;
349		else if (tfo->tpg_check_prot_fabric_only)
350			se_sess->sess_prot_type = se_nacl->saved_prot_type =
351					tfo->tpg_check_prot_fabric_only(se_tpg);
352		/*
353		 * If the fabric module supports an ISID based TransportID,
354		 * save this value in binary from the fabric I_T Nexus now.
355		 */
356		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
357			memset(&buf[0], 0, PR_REG_ISID_LEN);
358			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
359					&buf[0], PR_REG_ISID_LEN);
360			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
361		}
362		kref_get(&se_nacl->acl_kref);
363
364		spin_lock_irq(&se_nacl->nacl_sess_lock);
365		/*
366		 * The se_nacl->nacl_sess pointer will be set to the
367		 * last active I_T Nexus for each struct se_node_acl.
368		 */
369		se_nacl->nacl_sess = se_sess;
370
371		list_add_tail(&se_sess->sess_acl_list,
372			      &se_nacl->acl_sess_list);
373		spin_unlock_irq(&se_nacl->nacl_sess_lock);
374	}
375	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
376
377	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
378		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
379}
380EXPORT_SYMBOL(__transport_register_session);
381
382void transport_register_session(
383	struct se_portal_group *se_tpg,
384	struct se_node_acl *se_nacl,
385	struct se_session *se_sess,
386	void *fabric_sess_ptr)
387{
388	unsigned long flags;
389
390	spin_lock_irqsave(&se_tpg->session_lock, flags);
391	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
392	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
393}
394EXPORT_SYMBOL(transport_register_session);
395
396static void target_release_session(struct kref *kref)
397{
398	struct se_session *se_sess = container_of(kref,
399			struct se_session, sess_kref);
400	struct se_portal_group *se_tpg = se_sess->se_tpg;
401
402	se_tpg->se_tpg_tfo->close_session(se_sess);
403}
404
405void target_get_session(struct se_session *se_sess)
406{
407	kref_get(&se_sess->sess_kref);
408}
409EXPORT_SYMBOL(target_get_session);
410
411void target_put_session(struct se_session *se_sess)
412{
413	struct se_portal_group *tpg = se_sess->se_tpg;
414
415	if (tpg->se_tpg_tfo->put_session != NULL) {
416		tpg->se_tpg_tfo->put_session(se_sess);
417		return;
418	}
419	kref_put(&se_sess->sess_kref, target_release_session);
420}
421EXPORT_SYMBOL(target_put_session);
422
423ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
424{
425	struct se_session *se_sess;
426	ssize_t len = 0;
427
428	spin_lock_bh(&se_tpg->session_lock);
429	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
430		if (!se_sess->se_node_acl)
431			continue;
432		if (!se_sess->se_node_acl->dynamic_node_acl)
433			continue;
434		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
435			break;
436
437		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
438				se_sess->se_node_acl->initiatorname);
439		len += 1; /* Include NULL terminator */
440	}
441	spin_unlock_bh(&se_tpg->session_lock);
442
443	return len;
444}
445EXPORT_SYMBOL(target_show_dynamic_sessions);
446
447static void target_complete_nacl(struct kref *kref)
448{
449	struct se_node_acl *nacl = container_of(kref,
450				struct se_node_acl, acl_kref);
451
452	complete(&nacl->acl_free_comp);
453}
454
455void target_put_nacl(struct se_node_acl *nacl)
456{
457	kref_put(&nacl->acl_kref, target_complete_nacl);
458}
459
460void transport_deregister_session_configfs(struct se_session *se_sess)
461{
462	struct se_node_acl *se_nacl;
463	unsigned long flags;
464	/*
465	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
466	 */
467	se_nacl = se_sess->se_node_acl;
468	if (se_nacl) {
469		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
470		if (se_nacl->acl_stop == 0)
471			list_del(&se_sess->sess_acl_list);
472		/*
473		 * If the session list is empty, then clear the pointer.
474		 * Otherwise, set the struct se_session pointer from the tail
475		 * element of the per struct se_node_acl active session list.
476		 */
477		if (list_empty(&se_nacl->acl_sess_list))
478			se_nacl->nacl_sess = NULL;
479		else {
480			se_nacl->nacl_sess = container_of(
481					se_nacl->acl_sess_list.prev,
482					struct se_session, sess_acl_list);
483		}
484		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
485	}
486}
487EXPORT_SYMBOL(transport_deregister_session_configfs);
488
489void transport_free_session(struct se_session *se_sess)
490{
491	if (se_sess->sess_cmd_map) {
492		percpu_ida_destroy(&se_sess->sess_tag_pool);
493		if (is_vmalloc_addr(se_sess->sess_cmd_map))
494			vfree(se_sess->sess_cmd_map);
495		else
496			kfree(se_sess->sess_cmd_map);
497	}
498	kmem_cache_free(se_sess_cache, se_sess);
499}
500EXPORT_SYMBOL(transport_free_session);
501
502void transport_deregister_session(struct se_session *se_sess)
503{
504	struct se_portal_group *se_tpg = se_sess->se_tpg;
505	const struct target_core_fabric_ops *se_tfo;
506	struct se_node_acl *se_nacl;
507	unsigned long flags;
508	bool comp_nacl = true;
509
510	if (!se_tpg) {
511		transport_free_session(se_sess);
512		return;
513	}
514	se_tfo = se_tpg->se_tpg_tfo;
515
516	spin_lock_irqsave(&se_tpg->session_lock, flags);
517	list_del(&se_sess->sess_list);
518	se_sess->se_tpg = NULL;
519	se_sess->fabric_sess_ptr = NULL;
520	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
521
522	/*
523	 * Determine if we need to do extra work for this initiator node's
524	 * struct se_node_acl if it had been previously dynamically generated.
525	 */
526	se_nacl = se_sess->se_node_acl;
527
528	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
529	if (se_nacl && se_nacl->dynamic_node_acl) {
530		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
531			list_del(&se_nacl->acl_list);
532			se_tpg->num_node_acls--;
533			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
534			core_tpg_wait_for_nacl_pr_ref(se_nacl);
535			core_free_device_list_for_node(se_nacl, se_tpg);
536			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
537
538			comp_nacl = false;
539			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
540		}
541	}
542	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
543
544	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
545		se_tpg->se_tpg_tfo->get_fabric_name());
546	/*
547	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
548	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
549	 * removal context.
550	 */
551	if (se_nacl && comp_nacl)
552		target_put_nacl(se_nacl);
553
554	transport_free_session(se_sess);
555}
556EXPORT_SYMBOL(transport_deregister_session);
557
558static void target_remove_from_state_list(struct se_cmd *cmd)
559{
560	struct se_device *dev = cmd->se_dev;
561	unsigned long flags;
562
563	if (!dev)
564		return;
565
566	if (cmd->transport_state & CMD_T_BUSY)
567		return;
568
569	spin_lock_irqsave(&dev->execute_task_lock, flags);
570	if (cmd->state_active) {
571		list_del(&cmd->state_list);
572		cmd->state_active = false;
573	}
574	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
575}
576
577static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
578				    bool write_pending)
579{
580	unsigned long flags;
581
582	if (remove_from_lists) {
583		target_remove_from_state_list(cmd);
584
585		/*
586		 * Clear struct se_cmd->se_lun before the handoff to FE.
587		 */
588		cmd->se_lun = NULL;
589	}
590
591	spin_lock_irqsave(&cmd->t_state_lock, flags);
592	if (write_pending)
593		cmd->t_state = TRANSPORT_WRITE_PENDING;
594
595	/*
596	 * Determine if frontend context caller is requesting the stopping of
597	 * this command for frontend exceptions.
598	 */
599	if (cmd->transport_state & CMD_T_STOP) {
600		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
601			__func__, __LINE__,
602			cmd->se_tfo->get_task_tag(cmd));
603
604		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
605
606		complete_all(&cmd->t_transport_stop_comp);
607		return 1;
608	}
609
610	cmd->transport_state &= ~CMD_T_ACTIVE;
611	if (remove_from_lists) {
612		/*
613		 * Some fabric modules like tcm_loop can release
614		 * their internally allocated I/O reference now and
615		 * struct se_cmd now.
616		 *
617		 * Fabric modules are expected to return '1' here if the
618		 * se_cmd being passed is released at this point,
619		 * or zero if not being released.
620		 */
621		if (cmd->se_tfo->check_stop_free != NULL) {
622			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
623			return cmd->se_tfo->check_stop_free(cmd);
624		}
625	}
626
627	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
628	return 0;
629}
630
631static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
632{
633	return transport_cmd_check_stop(cmd, true, false);
634}
635
636static void transport_lun_remove_cmd(struct se_cmd *cmd)
637{
638	struct se_lun *lun = cmd->se_lun;
639
640	if (!lun)
641		return;
642
643	if (cmpxchg(&cmd->lun_ref_active, true, false))
644		percpu_ref_put(&lun->lun_ref);
645}
646
647void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
648{
649	bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
650
651	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
652		transport_lun_remove_cmd(cmd);
653	/*
654	 * Allow the fabric driver to unmap any resources before
655	 * releasing the descriptor via TFO->release_cmd()
656	 */
657	if (remove)
658		cmd->se_tfo->aborted_task(cmd);
659
660	if (transport_cmd_check_stop_to_fabric(cmd))
661		return;
662	if (remove && ack_kref)
663		transport_put_cmd(cmd);
664}
665
666static void target_complete_failure_work(struct work_struct *work)
667{
668	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
669
670	transport_generic_request_failure(cmd,
671			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
672}
673
674/*
675 * Used when asking transport to copy Sense Data from the underlying
676 * Linux/SCSI struct scsi_cmnd
677 */
678static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
679{
680	struct se_device *dev = cmd->se_dev;
681
682	WARN_ON(!cmd->se_lun);
683
684	if (!dev)
685		return NULL;
686
687	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
688		return NULL;
689
690	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
691
692	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
693		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
694	return cmd->sense_buffer;
695}
696
697void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
698{
699	struct se_device *dev = cmd->se_dev;
700	int success = scsi_status == GOOD;
701	unsigned long flags;
702
703	cmd->scsi_status = scsi_status;
704
705
706	spin_lock_irqsave(&cmd->t_state_lock, flags);
707	cmd->transport_state &= ~CMD_T_BUSY;
708
709	if (dev && dev->transport->transport_complete) {
710		dev->transport->transport_complete(cmd,
711				cmd->t_data_sg,
712				transport_get_sense_buffer(cmd));
713		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
714			success = 1;
715	}
716
717	/*
718	 * See if we are waiting to complete for an exception condition.
719	 */
720	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
721		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
722		complete(&cmd->task_stop_comp);
723		return;
724	}
725
726	/*
727	 * Check for case where an explicit ABORT_TASK has been received
728	 * and transport_wait_for_tasks() will be waiting for completion..
729	 */
730	if (cmd->transport_state & CMD_T_ABORTED ||
731	    cmd->transport_state & CMD_T_STOP) {
732		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
733		complete_all(&cmd->t_transport_stop_comp);
734		return;
735	} else if (!success) {
736		INIT_WORK(&cmd->work, target_complete_failure_work);
737	} else {
738		INIT_WORK(&cmd->work, target_complete_ok_work);
739	}
740
741	cmd->t_state = TRANSPORT_COMPLETE;
742	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
743	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
744
745	queue_work(target_completion_wq, &cmd->work);
746}
747EXPORT_SYMBOL(target_complete_cmd);
748
749void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
750{
751	if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
752		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
753			cmd->residual_count += cmd->data_length - length;
754		} else {
755			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
756			cmd->residual_count = cmd->data_length - length;
757		}
758
759		cmd->data_length = length;
760	}
761
762	target_complete_cmd(cmd, scsi_status);
763}
764EXPORT_SYMBOL(target_complete_cmd_with_length);
765
766static void target_add_to_state_list(struct se_cmd *cmd)
767{
768	struct se_device *dev = cmd->se_dev;
769	unsigned long flags;
770
771	spin_lock_irqsave(&dev->execute_task_lock, flags);
772	if (!cmd->state_active) {
773		list_add_tail(&cmd->state_list, &dev->state_list);
774		cmd->state_active = true;
775	}
776	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
777}
778
779/*
780 * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
781 */
782static void transport_write_pending_qf(struct se_cmd *cmd);
783static void transport_complete_qf(struct se_cmd *cmd);
784
785void target_qf_do_work(struct work_struct *work)
786{
787	struct se_device *dev = container_of(work, struct se_device,
788					qf_work_queue);
789	LIST_HEAD(qf_cmd_list);
790	struct se_cmd *cmd, *cmd_tmp;
791
792	spin_lock_irq(&dev->qf_cmd_lock);
793	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
794	spin_unlock_irq(&dev->qf_cmd_lock);
795
796	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
797		list_del(&cmd->se_qf_node);
798		atomic_dec_mb(&dev->dev_qf_count);
799
800		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
801			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
802			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
803			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
804			: "UNKNOWN");
805
806		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
807			transport_write_pending_qf(cmd);
808		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
809			transport_complete_qf(cmd);
810	}
811}
812
813unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
814{
815	switch (cmd->data_direction) {
816	case DMA_NONE:
817		return "NONE";
818	case DMA_FROM_DEVICE:
819		return "READ";
820	case DMA_TO_DEVICE:
821		return "WRITE";
822	case DMA_BIDIRECTIONAL:
823		return "BIDI";
824	default:
825		break;
826	}
827
828	return "UNKNOWN";
829}
830
831void transport_dump_dev_state(
832	struct se_device *dev,
833	char *b,
834	int *bl)
835{
836	*bl += sprintf(b + *bl, "Status: ");
837	if (dev->export_count)
838		*bl += sprintf(b + *bl, "ACTIVATED");
839	else
840		*bl += sprintf(b + *bl, "DEACTIVATED");
841
842	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
843	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
844		dev->dev_attrib.block_size,
845		dev->dev_attrib.hw_max_sectors);
846	*bl += sprintf(b + *bl, "        ");
847}
848
849void transport_dump_vpd_proto_id(
850	struct t10_vpd *vpd,
851	unsigned char *p_buf,
852	int p_buf_len)
853{
854	unsigned char buf[VPD_TMP_BUF_SIZE];
855	int len;
856
857	memset(buf, 0, VPD_TMP_BUF_SIZE);
858	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
859
860	switch (vpd->protocol_identifier) {
861	case 0x00:
862		sprintf(buf+len, "Fibre Channel\n");
863		break;
864	case 0x10:
865		sprintf(buf+len, "Parallel SCSI\n");
866		break;
867	case 0x20:
868		sprintf(buf+len, "SSA\n");
869		break;
870	case 0x30:
871		sprintf(buf+len, "IEEE 1394\n");
872		break;
873	case 0x40:
874		sprintf(buf+len, "SCSI Remote Direct Memory Access"
875				" Protocol\n");
876		break;
877	case 0x50:
878		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
879		break;
880	case 0x60:
881		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
882		break;
883	case 0x70:
884		sprintf(buf+len, "Automation/Drive Interface Transport"
885				" Protocol\n");
886		break;
887	case 0x80:
888		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
889		break;
890	default:
891		sprintf(buf+len, "Unknown 0x%02x\n",
892				vpd->protocol_identifier);
893		break;
894	}
895
896	if (p_buf)
897		strncpy(p_buf, buf, p_buf_len);
898	else
899		pr_debug("%s", buf);
900}
901
902void
903transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
904{
905	/*
906	 * Check if the Protocol Identifier Valid (PIV) bit is set..
907	 *
908	 * from spc3r23.pdf section 7.5.1
909	 */
910	 if (page_83[1] & 0x80) {
911		vpd->protocol_identifier = (page_83[0] & 0xf0);
912		vpd->protocol_identifier_set = 1;
913		transport_dump_vpd_proto_id(vpd, NULL, 0);
914	}
915}
916EXPORT_SYMBOL(transport_set_vpd_proto_id);
917
918int transport_dump_vpd_assoc(
919	struct t10_vpd *vpd,
920	unsigned char *p_buf,
921	int p_buf_len)
922{
923	unsigned char buf[VPD_TMP_BUF_SIZE];
924	int ret = 0;
925	int len;
926
927	memset(buf, 0, VPD_TMP_BUF_SIZE);
928	len = sprintf(buf, "T10 VPD Identifier Association: ");
929
930	switch (vpd->association) {
931	case 0x00:
932		sprintf(buf+len, "addressed logical unit\n");
933		break;
934	case 0x10:
935		sprintf(buf+len, "target port\n");
936		break;
937	case 0x20:
938		sprintf(buf+len, "SCSI target device\n");
939		break;
940	default:
941		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
942		ret = -EINVAL;
943		break;
944	}
945
946	if (p_buf)
947		strncpy(p_buf, buf, p_buf_len);
948	else
949		pr_debug("%s", buf);
950
951	return ret;
952}
953
954int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
955{
956	/*
957	 * The VPD identification association..
958	 *
959	 * from spc3r23.pdf Section 7.6.3.1 Table 297
960	 */
961	vpd->association = (page_83[1] & 0x30);
962	return transport_dump_vpd_assoc(vpd, NULL, 0);
963}
964EXPORT_SYMBOL(transport_set_vpd_assoc);
965
966int transport_dump_vpd_ident_type(
967	struct t10_vpd *vpd,
968	unsigned char *p_buf,
969	int p_buf_len)
970{
971	unsigned char buf[VPD_TMP_BUF_SIZE];
972	int ret = 0;
973	int len;
974
975	memset(buf, 0, VPD_TMP_BUF_SIZE);
976	len = sprintf(buf, "T10 VPD Identifier Type: ");
977
978	switch (vpd->device_identifier_type) {
979	case 0x00:
980		sprintf(buf+len, "Vendor specific\n");
981		break;
982	case 0x01:
983		sprintf(buf+len, "T10 Vendor ID based\n");
984		break;
985	case 0x02:
986		sprintf(buf+len, "EUI-64 based\n");
987		break;
988	case 0x03:
989		sprintf(buf+len, "NAA\n");
990		break;
991	case 0x04:
992		sprintf(buf+len, "Relative target port identifier\n");
993		break;
994	case 0x08:
995		sprintf(buf+len, "SCSI name string\n");
996		break;
997	default:
998		sprintf(buf+len, "Unsupported: 0x%02x\n",
999				vpd->device_identifier_type);
1000		ret = -EINVAL;
1001		break;
1002	}
1003
1004	if (p_buf) {
1005		if (p_buf_len < strlen(buf)+1)
1006			return -EINVAL;
1007		strncpy(p_buf, buf, p_buf_len);
1008	} else {
1009		pr_debug("%s", buf);
1010	}
1011
1012	return ret;
1013}
1014
1015int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1016{
1017	/*
1018	 * The VPD identifier type..
1019	 *
1020	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1021	 */
1022	vpd->device_identifier_type = (page_83[1] & 0x0f);
1023	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1024}
1025EXPORT_SYMBOL(transport_set_vpd_ident_type);
1026
1027int transport_dump_vpd_ident(
1028	struct t10_vpd *vpd,
1029	unsigned char *p_buf,
1030	int p_buf_len)
1031{
1032	unsigned char buf[VPD_TMP_BUF_SIZE];
1033	int ret = 0;
1034
1035	memset(buf, 0, VPD_TMP_BUF_SIZE);
1036
1037	switch (vpd->device_identifier_code_set) {
1038	case 0x01: /* Binary */
1039		snprintf(buf, sizeof(buf),
1040			"T10 VPD Binary Device Identifier: %s\n",
1041			&vpd->device_identifier[0]);
1042		break;
1043	case 0x02: /* ASCII */
1044		snprintf(buf, sizeof(buf),
1045			"T10 VPD ASCII Device Identifier: %s\n",
1046			&vpd->device_identifier[0]);
1047		break;
1048	case 0x03: /* UTF-8 */
1049		snprintf(buf, sizeof(buf),
1050			"T10 VPD UTF-8 Device Identifier: %s\n",
1051			&vpd->device_identifier[0]);
1052		break;
1053	default:
1054		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1055			" 0x%02x", vpd->device_identifier_code_set);
1056		ret = -EINVAL;
1057		break;
1058	}
1059
1060	if (p_buf)
1061		strncpy(p_buf, buf, p_buf_len);
1062	else
1063		pr_debug("%s", buf);
1064
1065	return ret;
1066}
1067
1068int
1069transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1070{
1071	static const char hex_str[] = "0123456789abcdef";
1072	int j = 0, i = 4; /* offset to start of the identifier */
1073
1074	/*
1075	 * The VPD Code Set (encoding)
1076	 *
1077	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1078	 */
1079	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1080	switch (vpd->device_identifier_code_set) {
1081	case 0x01: /* Binary */
1082		vpd->device_identifier[j++] =
1083				hex_str[vpd->device_identifier_type];
1084		while (i < (4 + page_83[3])) {
1085			vpd->device_identifier[j++] =
1086				hex_str[(page_83[i] & 0xf0) >> 4];
1087			vpd->device_identifier[j++] =
1088				hex_str[page_83[i] & 0x0f];
1089			i++;
1090		}
1091		break;
1092	case 0x02: /* ASCII */
1093	case 0x03: /* UTF-8 */
1094		while (i < (4 + page_83[3]))
1095			vpd->device_identifier[j++] = page_83[i++];
1096		break;
1097	default:
1098		break;
1099	}
1100
1101	return transport_dump_vpd_ident(vpd, NULL, 0);
1102}
1103EXPORT_SYMBOL(transport_set_vpd_ident);
1104
1105sense_reason_t
1106target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1107{
1108	struct se_device *dev = cmd->se_dev;
1109
1110	if (cmd->unknown_data_length) {
1111		cmd->data_length = size;
1112	} else if (size != cmd->data_length) {
1113		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1114			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1115			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1116				cmd->data_length, size, cmd->t_task_cdb[0]);
1117
1118		if (cmd->data_direction == DMA_TO_DEVICE) {
1119			pr_err("Rejecting underflow/overflow"
1120					" WRITE data\n");
1121			return TCM_INVALID_CDB_FIELD;
1122		}
1123		/*
1124		 * Reject READ_* or WRITE_* with overflow/underflow for
1125		 * type SCF_SCSI_DATA_CDB.
1126		 */
1127		if (dev->dev_attrib.block_size != 512)  {
1128			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1129				" CDB on non 512-byte sector setup subsystem"
1130				" plugin: %s\n", dev->transport->name);
1131			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1132			return TCM_INVALID_CDB_FIELD;
1133		}
1134		/*
1135		 * For the overflow case keep the existing fabric provided
1136		 * ->data_length.  Otherwise for the underflow case, reset
1137		 * ->data_length to the smaller SCSI expected data transfer
1138		 * length.
1139		 */
1140		if (size > cmd->data_length) {
1141			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1142			cmd->residual_count = (size - cmd->data_length);
1143		} else {
1144			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1145			cmd->residual_count = (cmd->data_length - size);
1146			cmd->data_length = size;
1147		}
1148	}
1149
1150	return 0;
1151
1152}
1153
1154/*
1155 * Used by fabric modules containing a local struct se_cmd within their
1156 * fabric dependent per I/O descriptor.
1157 */
1158void transport_init_se_cmd(
1159	struct se_cmd *cmd,
1160	const struct target_core_fabric_ops *tfo,
1161	struct se_session *se_sess,
1162	u32 data_length,
1163	int data_direction,
1164	int task_attr,
1165	unsigned char *sense_buffer)
1166{
1167	INIT_LIST_HEAD(&cmd->se_delayed_node);
1168	INIT_LIST_HEAD(&cmd->se_qf_node);
1169	INIT_LIST_HEAD(&cmd->se_cmd_list);
1170	INIT_LIST_HEAD(&cmd->state_list);
1171	init_completion(&cmd->t_transport_stop_comp);
1172	init_completion(&cmd->cmd_wait_comp);
1173	init_completion(&cmd->task_stop_comp);
1174	spin_lock_init(&cmd->t_state_lock);
1175	kref_init(&cmd->cmd_kref);
1176	cmd->transport_state = CMD_T_DEV_ACTIVE;
1177
1178	cmd->se_tfo = tfo;
1179	cmd->se_sess = se_sess;
1180	cmd->data_length = data_length;
1181	cmd->data_direction = data_direction;
1182	cmd->sam_task_attr = task_attr;
1183	cmd->sense_buffer = sense_buffer;
1184
1185	cmd->state_active = false;
1186}
1187EXPORT_SYMBOL(transport_init_se_cmd);
1188
1189static sense_reason_t
1190transport_check_alloc_task_attr(struct se_cmd *cmd)
1191{
1192	struct se_device *dev = cmd->se_dev;
1193
1194	/*
1195	 * Check if SAM Task Attribute emulation is enabled for this
1196	 * struct se_device storage object
1197	 */
1198	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1199		return 0;
1200
1201	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1202		pr_debug("SAM Task Attribute ACA"
1203			" emulation is not supported\n");
1204		return TCM_INVALID_CDB_FIELD;
1205	}
1206	/*
1207	 * Used to determine when ORDERED commands should go from
1208	 * Dormant to Active status.
1209	 */
1210	cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1211	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1212			cmd->se_ordered_id, cmd->sam_task_attr,
1213			dev->transport->name);
1214	return 0;
1215}
1216
1217sense_reason_t
1218target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1219{
1220	struct se_device *dev = cmd->se_dev;
1221	sense_reason_t ret;
1222
1223	/*
1224	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1225	 * for VARIABLE_LENGTH_CMD
1226	 */
1227	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1228		pr_err("Received SCSI CDB with command_size: %d that"
1229			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1230			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1231		return TCM_INVALID_CDB_FIELD;
1232	}
1233	/*
1234	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1235	 * allocate the additional extended CDB buffer now..  Otherwise
1236	 * setup the pointer from __t_task_cdb to t_task_cdb.
1237	 */
1238	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1239		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1240						GFP_KERNEL);
1241		if (!cmd->t_task_cdb) {
1242			pr_err("Unable to allocate cmd->t_task_cdb"
1243				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1244				scsi_command_size(cdb),
1245				(unsigned long)sizeof(cmd->__t_task_cdb));
1246			return TCM_OUT_OF_RESOURCES;
1247		}
1248	} else
1249		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1250	/*
1251	 * Copy the original CDB into cmd->
1252	 */
1253	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1254
1255	trace_target_sequencer_start(cmd);
1256
1257	/*
1258	 * Check for an existing UNIT ATTENTION condition
1259	 */
1260	ret = target_scsi3_ua_check(cmd);
1261	if (ret)
1262		return ret;
1263
1264	ret = target_alua_state_check(cmd);
1265	if (ret)
1266		return ret;
1267
1268	ret = target_check_reservation(cmd);
1269	if (ret) {
1270		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1271		return ret;
1272	}
1273
1274	ret = dev->transport->parse_cdb(cmd);
1275	if (ret)
1276		return ret;
1277
1278	ret = transport_check_alloc_task_attr(cmd);
1279	if (ret)
1280		return ret;
1281
1282	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1283
1284	spin_lock(&cmd->se_lun->lun_sep_lock);
1285	if (cmd->se_lun->lun_sep)
1286		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1287	spin_unlock(&cmd->se_lun->lun_sep_lock);
1288	return 0;
1289}
1290EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1291
1292/*
1293 * Used by fabric module frontends to queue tasks directly.
1294 * Many only be used from process context only
1295 */
1296int transport_handle_cdb_direct(
1297	struct se_cmd *cmd)
1298{
1299	sense_reason_t ret;
1300
1301	if (!cmd->se_lun) {
1302		dump_stack();
1303		pr_err("cmd->se_lun is NULL\n");
1304		return -EINVAL;
1305	}
1306	if (in_interrupt()) {
1307		dump_stack();
1308		pr_err("transport_generic_handle_cdb cannot be called"
1309				" from interrupt context\n");
1310		return -EINVAL;
1311	}
1312	/*
1313	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1314	 * outstanding descriptors are handled correctly during shutdown via
1315	 * transport_wait_for_tasks()
1316	 *
1317	 * Also, we don't take cmd->t_state_lock here as we only expect
1318	 * this to be called for initial descriptor submission.
1319	 */
1320	cmd->t_state = TRANSPORT_NEW_CMD;
1321	cmd->transport_state |= CMD_T_ACTIVE;
1322
1323	/*
1324	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1325	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1326	 * and call transport_generic_request_failure() if necessary..
1327	 */
1328	ret = transport_generic_new_cmd(cmd);
1329	if (ret)
1330		transport_generic_request_failure(cmd, ret);
1331	return 0;
1332}
1333EXPORT_SYMBOL(transport_handle_cdb_direct);
1334
1335sense_reason_t
1336transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1337		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1338{
1339	if (!sgl || !sgl_count)
1340		return 0;
1341
1342	/*
1343	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1344	 * scatterlists already have been set to follow what the fabric
1345	 * passes for the original expected data transfer length.
1346	 */
1347	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1348		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1349			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1350		return TCM_INVALID_CDB_FIELD;
1351	}
1352
1353	cmd->t_data_sg = sgl;
1354	cmd->t_data_nents = sgl_count;
1355
1356	if (sgl_bidi && sgl_bidi_count) {
1357		cmd->t_bidi_data_sg = sgl_bidi;
1358		cmd->t_bidi_data_nents = sgl_bidi_count;
1359	}
1360	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1361	return 0;
1362}
1363
1364/*
1365 * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1366 * 			 se_cmd + use pre-allocated SGL memory.
1367 *
1368 * @se_cmd: command descriptor to submit
1369 * @se_sess: associated se_sess for endpoint
1370 * @cdb: pointer to SCSI CDB
1371 * @sense: pointer to SCSI sense buffer
1372 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1373 * @data_length: fabric expected data transfer length
1374 * @task_addr: SAM task attribute
1375 * @data_dir: DMA data direction
1376 * @flags: flags for command submission from target_sc_flags_tables
1377 * @sgl: struct scatterlist memory for unidirectional mapping
1378 * @sgl_count: scatterlist count for unidirectional mapping
1379 * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1380 * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1381 * @sgl_prot: struct scatterlist memory protection information
1382 * @sgl_prot_count: scatterlist count for protection information
1383 *
1384 * Returns non zero to signal active I/O shutdown failure.  All other
1385 * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1386 * but still return zero here.
1387 *
1388 * This may only be called from process context, and also currently
1389 * assumes internal allocation of fabric payload buffer by target-core.
1390 */
1391int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1392		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1393		u32 data_length, int task_attr, int data_dir, int flags,
1394		struct scatterlist *sgl, u32 sgl_count,
1395		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1396		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1397{
1398	struct se_portal_group *se_tpg;
1399	sense_reason_t rc;
1400	int ret;
1401
1402	se_tpg = se_sess->se_tpg;
1403	BUG_ON(!se_tpg);
1404	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1405	BUG_ON(in_interrupt());
1406	/*
1407	 * Initialize se_cmd for target operation.  From this point
1408	 * exceptions are handled by sending exception status via
1409	 * target_core_fabric_ops->queue_status() callback
1410	 */
1411	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1412				data_length, data_dir, task_attr, sense);
1413	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1414		se_cmd->unknown_data_length = 1;
1415	/*
1416	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1417	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1418	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1419	 * kref_put() to happen during fabric packet acknowledgement.
1420	 */
1421	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1422	if (ret)
1423		return ret;
1424	/*
1425	 * Signal bidirectional data payloads to target-core
1426	 */
1427	if (flags & TARGET_SCF_BIDI_OP)
1428		se_cmd->se_cmd_flags |= SCF_BIDI;
1429	/*
1430	 * Locate se_lun pointer and attach it to struct se_cmd
1431	 */
1432	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1433	if (rc) {
1434		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1435		target_put_sess_cmd(se_cmd);
1436		return 0;
1437	}
1438
1439	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1440	if (rc != 0) {
1441		transport_generic_request_failure(se_cmd, rc);
1442		return 0;
1443	}
1444
1445	/*
1446	 * Save pointers for SGLs containing protection information,
1447	 * if present.
1448	 */
1449	if (sgl_prot_count) {
1450		se_cmd->t_prot_sg = sgl_prot;
1451		se_cmd->t_prot_nents = sgl_prot_count;
1452	}
1453
1454	/*
1455	 * When a non zero sgl_count has been passed perform SGL passthrough
1456	 * mapping for pre-allocated fabric memory instead of having target
1457	 * core perform an internal SGL allocation..
1458	 */
1459	if (sgl_count != 0) {
1460		BUG_ON(!sgl);
1461
1462		/*
1463		 * A work-around for tcm_loop as some userspace code via
1464		 * scsi-generic do not memset their associated read buffers,
1465		 * so go ahead and do that here for type non-data CDBs.  Also
1466		 * note that this is currently guaranteed to be a single SGL
1467		 * for this case by target core in target_setup_cmd_from_cdb()
1468		 * -> transport_generic_cmd_sequencer().
1469		 */
1470		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1471		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1472			unsigned char *buf = NULL;
1473
1474			if (sgl)
1475				buf = kmap(sg_page(sgl)) + sgl->offset;
1476
1477			if (buf) {
1478				memset(buf, 0, sgl->length);
1479				kunmap(sg_page(sgl));
1480			}
1481		}
1482
1483		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1484				sgl_bidi, sgl_bidi_count);
1485		if (rc != 0) {
1486			transport_generic_request_failure(se_cmd, rc);
1487			return 0;
1488		}
1489	}
1490
1491	/*
1492	 * Check if we need to delay processing because of ALUA
1493	 * Active/NonOptimized primary access state..
1494	 */
1495	core_alua_check_nonop_delay(se_cmd);
1496
1497	transport_handle_cdb_direct(se_cmd);
1498	return 0;
1499}
1500EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1501
1502/*
1503 * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1504 *
1505 * @se_cmd: command descriptor to submit
1506 * @se_sess: associated se_sess for endpoint
1507 * @cdb: pointer to SCSI CDB
1508 * @sense: pointer to SCSI sense buffer
1509 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1510 * @data_length: fabric expected data transfer length
1511 * @task_addr: SAM task attribute
1512 * @data_dir: DMA data direction
1513 * @flags: flags for command submission from target_sc_flags_tables
1514 *
1515 * Returns non zero to signal active I/O shutdown failure.  All other
1516 * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1517 * but still return zero here.
1518 *
1519 * This may only be called from process context, and also currently
1520 * assumes internal allocation of fabric payload buffer by target-core.
1521 *
1522 * It also assumes interal target core SGL memory allocation.
1523 */
1524int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1525		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1526		u32 data_length, int task_attr, int data_dir, int flags)
1527{
1528	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1529			unpacked_lun, data_length, task_attr, data_dir,
1530			flags, NULL, 0, NULL, 0, NULL, 0);
1531}
1532EXPORT_SYMBOL(target_submit_cmd);
1533
1534static void target_complete_tmr_failure(struct work_struct *work)
1535{
1536	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1537
1538	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1539	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1540
1541	transport_cmd_check_stop_to_fabric(se_cmd);
1542}
1543
1544/**
1545 * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1546 *                     for TMR CDBs
1547 *
1548 * @se_cmd: command descriptor to submit
1549 * @se_sess: associated se_sess for endpoint
1550 * @sense: pointer to SCSI sense buffer
1551 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1552 * @fabric_context: fabric context for TMR req
1553 * @tm_type: Type of TM request
1554 * @gfp: gfp type for caller
1555 * @tag: referenced task tag for TMR_ABORT_TASK
1556 * @flags: submit cmd flags
1557 *
1558 * Callable from all contexts.
1559 **/
1560
1561int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1562		unsigned char *sense, u32 unpacked_lun,
1563		void *fabric_tmr_ptr, unsigned char tm_type,
1564		gfp_t gfp, unsigned int tag, int flags)
1565{
1566	struct se_portal_group *se_tpg;
1567	int ret;
1568
1569	se_tpg = se_sess->se_tpg;
1570	BUG_ON(!se_tpg);
1571
1572	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1573			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1574	/*
1575	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1576	 * allocation failure.
1577	 */
1578	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1579	if (ret < 0)
1580		return -ENOMEM;
1581
1582	if (tm_type == TMR_ABORT_TASK)
1583		se_cmd->se_tmr_req->ref_task_tag = tag;
1584
1585	/* See target_submit_cmd for commentary */
1586	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1587	if (ret) {
1588		core_tmr_release_req(se_cmd->se_tmr_req);
1589		return ret;
1590	}
1591
1592	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1593	if (ret) {
1594		/*
1595		 * For callback during failure handling, push this work off
1596		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1597		 */
1598		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1599		schedule_work(&se_cmd->work);
1600		return 0;
1601	}
1602	transport_generic_handle_tmr(se_cmd);
1603	return 0;
1604}
1605EXPORT_SYMBOL(target_submit_tmr);
1606
1607/*
1608 * If the cmd is active, request it to be stopped and sleep until it
1609 * has completed.
1610 */
1611bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1612	__releases(&cmd->t_state_lock)
1613	__acquires(&cmd->t_state_lock)
1614{
1615	bool was_active = false;
1616
1617	if (cmd->transport_state & CMD_T_BUSY) {
1618		cmd->transport_state |= CMD_T_REQUEST_STOP;
1619		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1620
1621		pr_debug("cmd %p waiting to complete\n", cmd);
1622		wait_for_completion(&cmd->task_stop_comp);
1623		pr_debug("cmd %p stopped successfully\n", cmd);
1624
1625		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1626		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1627		cmd->transport_state &= ~CMD_T_BUSY;
1628		was_active = true;
1629	}
1630
1631	return was_active;
1632}
1633
1634/*
1635 * Handle SAM-esque emulation for generic transport request failures.
1636 */
1637void transport_generic_request_failure(struct se_cmd *cmd,
1638		sense_reason_t sense_reason)
1639{
1640	int ret = 0, post_ret = 0;
1641
1642	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1643		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1644		cmd->t_task_cdb[0]);
1645	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1646		cmd->se_tfo->get_cmd_state(cmd),
1647		cmd->t_state, sense_reason);
1648	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1649		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1650		(cmd->transport_state & CMD_T_STOP) != 0,
1651		(cmd->transport_state & CMD_T_SENT) != 0);
1652
1653	/*
1654	 * For SAM Task Attribute emulation for failed struct se_cmd
1655	 */
1656	transport_complete_task_attr(cmd);
1657	/*
1658	 * Handle special case for COMPARE_AND_WRITE failure, where the
1659	 * callback is expected to drop the per device ->caw_sem.
1660	 */
1661	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1662	     cmd->transport_complete_callback)
1663		cmd->transport_complete_callback(cmd, false, &post_ret);
1664
1665	switch (sense_reason) {
1666	case TCM_NON_EXISTENT_LUN:
1667	case TCM_UNSUPPORTED_SCSI_OPCODE:
1668	case TCM_INVALID_CDB_FIELD:
1669	case TCM_INVALID_PARAMETER_LIST:
1670	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1671	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1672	case TCM_UNKNOWN_MODE_PAGE:
1673	case TCM_WRITE_PROTECTED:
1674	case TCM_ADDRESS_OUT_OF_RANGE:
1675	case TCM_CHECK_CONDITION_ABORT_CMD:
1676	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1677	case TCM_CHECK_CONDITION_NOT_READY:
1678	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1679	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1680	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1681		break;
1682	case TCM_OUT_OF_RESOURCES:
1683		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1684		break;
1685	case TCM_RESERVATION_CONFLICT:
1686		/*
1687		 * No SENSE Data payload for this case, set SCSI Status
1688		 * and queue the response to $FABRIC_MOD.
1689		 *
1690		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1691		 */
1692		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1693		/*
1694		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1695		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1696		 * CONFLICT STATUS.
1697		 *
1698		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1699		 */
1700		if (cmd->se_sess &&
1701		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1702			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1703				cmd->orig_fe_lun, 0x2C,
1704				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1705
1706		trace_target_cmd_complete(cmd);
1707		ret = cmd->se_tfo-> queue_status(cmd);
1708		if (ret == -EAGAIN || ret == -ENOMEM)
1709			goto queue_full;
1710		goto check_stop;
1711	default:
1712		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1713			cmd->t_task_cdb[0], sense_reason);
1714		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1715		break;
1716	}
1717
1718	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1719	if (ret == -EAGAIN || ret == -ENOMEM)
1720		goto queue_full;
1721
1722check_stop:
1723	transport_lun_remove_cmd(cmd);
1724	if (!transport_cmd_check_stop_to_fabric(cmd))
1725		;
1726	return;
1727
1728queue_full:
1729	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1730	transport_handle_queue_full(cmd, cmd->se_dev);
1731}
1732EXPORT_SYMBOL(transport_generic_request_failure);
1733
1734void __target_execute_cmd(struct se_cmd *cmd)
1735{
1736	sense_reason_t ret;
1737
1738	if (cmd->execute_cmd) {
1739		ret = cmd->execute_cmd(cmd);
1740		if (ret) {
1741			spin_lock_irq(&cmd->t_state_lock);
1742			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1743			spin_unlock_irq(&cmd->t_state_lock);
1744
1745			transport_generic_request_failure(cmd, ret);
1746		}
1747	}
1748}
1749
1750static int target_write_prot_action(struct se_cmd *cmd)
1751{
1752	u32 sectors;
1753	/*
1754	 * Perform WRITE_INSERT of PI using software emulation when backend
1755	 * device has PI enabled, if the transport has not already generated
1756	 * PI using hardware WRITE_INSERT offload.
1757	 */
1758	switch (cmd->prot_op) {
1759	case TARGET_PROT_DOUT_INSERT:
1760		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1761			sbc_dif_generate(cmd);
1762		break;
1763	case TARGET_PROT_DOUT_STRIP:
1764		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1765			break;
1766
1767		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1768		cmd->pi_err = sbc_dif_verify_write(cmd, cmd->t_task_lba,
1769						   sectors, 0, NULL, 0);
1770		if (unlikely(cmd->pi_err)) {
1771			spin_lock_irq(&cmd->t_state_lock);
1772			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1773			spin_unlock_irq(&cmd->t_state_lock);
1774			transport_generic_request_failure(cmd, cmd->pi_err);
1775			return -1;
1776		}
1777		break;
1778	default:
1779		break;
1780	}
1781
1782	return 0;
1783}
1784
1785static bool target_handle_task_attr(struct se_cmd *cmd)
1786{
1787	struct se_device *dev = cmd->se_dev;
1788
1789	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1790		return false;
1791
1792	/*
1793	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1794	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1795	 */
1796	switch (cmd->sam_task_attr) {
1797	case TCM_HEAD_TAG:
1798		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1799			 "se_ordered_id: %u\n",
1800			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1801		return false;
1802	case TCM_ORDERED_TAG:
1803		atomic_inc_mb(&dev->dev_ordered_sync);
1804
1805		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1806			 " se_ordered_id: %u\n",
1807			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1808
1809		/*
1810		 * Execute an ORDERED command if no other older commands
1811		 * exist that need to be completed first.
1812		 */
1813		if (!atomic_read(&dev->simple_cmds))
1814			return false;
1815		break;
1816	default:
1817		/*
1818		 * For SIMPLE and UNTAGGED Task Attribute commands
1819		 */
1820		atomic_inc_mb(&dev->simple_cmds);
1821		break;
1822	}
1823
1824	if (atomic_read(&dev->dev_ordered_sync) == 0)
1825		return false;
1826
1827	spin_lock(&dev->delayed_cmd_lock);
1828	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1829	spin_unlock(&dev->delayed_cmd_lock);
1830
1831	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1832		" delayed CMD list, se_ordered_id: %u\n",
1833		cmd->t_task_cdb[0], cmd->sam_task_attr,
1834		cmd->se_ordered_id);
1835	return true;
1836}
1837
1838static int __transport_check_aborted_status(struct se_cmd *, int);
1839
1840void target_execute_cmd(struct se_cmd *cmd)
1841{
1842	/*
1843	 * Determine if frontend context caller is requesting the stopping of
1844	 * this command for frontend exceptions.
1845	 *
1846	 * If the received CDB has aleady been aborted stop processing it here.
1847	 */
1848	spin_lock_irq(&cmd->t_state_lock);
1849	if (__transport_check_aborted_status(cmd, 1)) {
1850		spin_unlock_irq(&cmd->t_state_lock);
1851		return;
1852	}
1853	if (cmd->transport_state & CMD_T_STOP) {
1854		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1855			__func__, __LINE__,
1856			cmd->se_tfo->get_task_tag(cmd));
1857
1858		spin_unlock_irq(&cmd->t_state_lock);
1859		complete_all(&cmd->t_transport_stop_comp);
1860		return;
1861	}
1862
1863	cmd->t_state = TRANSPORT_PROCESSING;
1864	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1865	spin_unlock_irq(&cmd->t_state_lock);
1866
1867	if (target_write_prot_action(cmd))
1868		return;
1869
1870	if (target_handle_task_attr(cmd)) {
1871		spin_lock_irq(&cmd->t_state_lock);
1872		cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1873		spin_unlock_irq(&cmd->t_state_lock);
1874		return;
1875	}
1876
1877	__target_execute_cmd(cmd);
1878}
1879EXPORT_SYMBOL(target_execute_cmd);
1880
1881/*
1882 * Process all commands up to the last received ORDERED task attribute which
1883 * requires another blocking boundary
1884 */
1885static void target_restart_delayed_cmds(struct se_device *dev)
1886{
1887	for (;;) {
1888		struct se_cmd *cmd;
1889
1890		spin_lock(&dev->delayed_cmd_lock);
1891		if (list_empty(&dev->delayed_cmd_list)) {
1892			spin_unlock(&dev->delayed_cmd_lock);
1893			break;
1894		}
1895
1896		cmd = list_entry(dev->delayed_cmd_list.next,
1897				 struct se_cmd, se_delayed_node);
1898		list_del(&cmd->se_delayed_node);
1899		spin_unlock(&dev->delayed_cmd_lock);
1900
1901		__target_execute_cmd(cmd);
1902
1903		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1904			break;
1905	}
1906}
1907
1908/*
1909 * Called from I/O completion to determine which dormant/delayed
1910 * and ordered cmds need to have their tasks added to the execution queue.
1911 */
1912static void transport_complete_task_attr(struct se_cmd *cmd)
1913{
1914	struct se_device *dev = cmd->se_dev;
1915
1916	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1917		return;
1918
1919	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1920		atomic_dec_mb(&dev->simple_cmds);
1921		dev->dev_cur_ordered_id++;
1922		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1923			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1924			cmd->se_ordered_id);
1925	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1926		dev->dev_cur_ordered_id++;
1927		pr_debug("Incremented dev_cur_ordered_id: %u for"
1928			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1929			cmd->se_ordered_id);
1930	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1931		atomic_dec_mb(&dev->dev_ordered_sync);
1932
1933		dev->dev_cur_ordered_id++;
1934		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1935			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1936	}
1937
1938	target_restart_delayed_cmds(dev);
1939}
1940
1941static void transport_complete_qf(struct se_cmd *cmd)
1942{
1943	int ret = 0;
1944
1945	transport_complete_task_attr(cmd);
1946
1947	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1948		trace_target_cmd_complete(cmd);
1949		ret = cmd->se_tfo->queue_status(cmd);
1950		goto out;
1951	}
1952
1953	switch (cmd->data_direction) {
1954	case DMA_FROM_DEVICE:
1955		trace_target_cmd_complete(cmd);
1956		ret = cmd->se_tfo->queue_data_in(cmd);
1957		break;
1958	case DMA_TO_DEVICE:
1959		if (cmd->se_cmd_flags & SCF_BIDI) {
1960			ret = cmd->se_tfo->queue_data_in(cmd);
1961			break;
1962		}
1963		/* Fall through for DMA_TO_DEVICE */
1964	case DMA_NONE:
1965		trace_target_cmd_complete(cmd);
1966		ret = cmd->se_tfo->queue_status(cmd);
1967		break;
1968	default:
1969		break;
1970	}
1971
1972out:
1973	if (ret < 0) {
1974		transport_handle_queue_full(cmd, cmd->se_dev);
1975		return;
1976	}
1977	transport_lun_remove_cmd(cmd);
1978	transport_cmd_check_stop_to_fabric(cmd);
1979}
1980
1981static void transport_handle_queue_full(
1982	struct se_cmd *cmd,
1983	struct se_device *dev)
1984{
1985	spin_lock_irq(&dev->qf_cmd_lock);
1986	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1987	atomic_inc_mb(&dev->dev_qf_count);
1988	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1989
1990	schedule_work(&cmd->se_dev->qf_work_queue);
1991}
1992
1993static bool target_read_prot_action(struct se_cmd *cmd)
1994{
1995	sense_reason_t rc;
1996
1997	switch (cmd->prot_op) {
1998	case TARGET_PROT_DIN_STRIP:
1999		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2000			rc = sbc_dif_read_strip(cmd);
2001			if (rc) {
2002				cmd->pi_err = rc;
2003				return true;
2004			}
2005		}
2006		break;
2007	case TARGET_PROT_DIN_INSERT:
2008		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2009			break;
2010
2011		sbc_dif_generate(cmd);
2012		break;
2013	default:
2014		break;
2015	}
2016
2017	return false;
2018}
2019
2020static void target_complete_ok_work(struct work_struct *work)
2021{
2022	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2023	int ret;
2024
2025	/*
2026	 * Check if we need to move delayed/dormant tasks from cmds on the
2027	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2028	 * Attribute.
2029	 */
2030	transport_complete_task_attr(cmd);
2031
2032	/*
2033	 * Check to schedule QUEUE_FULL work, or execute an existing
2034	 * cmd->transport_qf_callback()
2035	 */
2036	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2037		schedule_work(&cmd->se_dev->qf_work_queue);
2038
2039	/*
2040	 * Check if we need to send a sense buffer from
2041	 * the struct se_cmd in question.
2042	 */
2043	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2044		WARN_ON(!cmd->scsi_status);
2045		ret = transport_send_check_condition_and_sense(
2046					cmd, 0, 1);
2047		if (ret == -EAGAIN || ret == -ENOMEM)
2048			goto queue_full;
2049
2050		transport_lun_remove_cmd(cmd);
2051		transport_cmd_check_stop_to_fabric(cmd);
2052		return;
2053	}
2054	/*
2055	 * Check for a callback, used by amongst other things
2056	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2057	 */
2058	if (cmd->transport_complete_callback) {
2059		sense_reason_t rc;
2060		bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2061		bool zero_dl = !(cmd->data_length);
2062		int post_ret = 0;
2063
2064		rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2065		if (!rc && !post_ret) {
2066			if (caw && zero_dl)
2067				goto queue_rsp;
2068
2069			return;
2070		} else if (rc) {
2071			ret = transport_send_check_condition_and_sense(cmd,
2072						rc, 0);
2073			if (ret == -EAGAIN || ret == -ENOMEM)
2074				goto queue_full;
2075
2076			transport_lun_remove_cmd(cmd);
2077			transport_cmd_check_stop_to_fabric(cmd);
2078			return;
2079		}
2080	}
2081
2082queue_rsp:
2083	switch (cmd->data_direction) {
2084	case DMA_FROM_DEVICE:
2085		spin_lock(&cmd->se_lun->lun_sep_lock);
2086		if (cmd->se_lun->lun_sep) {
2087			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2088					cmd->data_length;
2089		}
2090		spin_unlock(&cmd->se_lun->lun_sep_lock);
2091		/*
2092		 * Perform READ_STRIP of PI using software emulation when
2093		 * backend had PI enabled, if the transport will not be
2094		 * performing hardware READ_STRIP offload.
2095		 */
2096		if (target_read_prot_action(cmd)) {
2097			ret = transport_send_check_condition_and_sense(cmd,
2098						cmd->pi_err, 0);
2099			if (ret == -EAGAIN || ret == -ENOMEM)
2100				goto queue_full;
2101
2102			transport_lun_remove_cmd(cmd);
2103			transport_cmd_check_stop_to_fabric(cmd);
2104			return;
2105		}
2106
2107		trace_target_cmd_complete(cmd);
2108		ret = cmd->se_tfo->queue_data_in(cmd);
2109		if (ret == -EAGAIN || ret == -ENOMEM)
2110			goto queue_full;
2111		break;
2112	case DMA_TO_DEVICE:
2113		spin_lock(&cmd->se_lun->lun_sep_lock);
2114		if (cmd->se_lun->lun_sep) {
2115			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2116				cmd->data_length;
2117		}
2118		spin_unlock(&cmd->se_lun->lun_sep_lock);
2119		/*
2120		 * Check if we need to send READ payload for BIDI-COMMAND
2121		 */
2122		if (cmd->se_cmd_flags & SCF_BIDI) {
2123			spin_lock(&cmd->se_lun->lun_sep_lock);
2124			if (cmd->se_lun->lun_sep) {
2125				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2126					cmd->data_length;
2127			}
2128			spin_unlock(&cmd->se_lun->lun_sep_lock);
2129			ret = cmd->se_tfo->queue_data_in(cmd);
2130			if (ret == -EAGAIN || ret == -ENOMEM)
2131				goto queue_full;
2132			break;
2133		}
2134		/* Fall through for DMA_TO_DEVICE */
2135	case DMA_NONE:
2136		trace_target_cmd_complete(cmd);
2137		ret = cmd->se_tfo->queue_status(cmd);
2138		if (ret == -EAGAIN || ret == -ENOMEM)
2139			goto queue_full;
2140		break;
2141	default:
2142		break;
2143	}
2144
2145	transport_lun_remove_cmd(cmd);
2146	transport_cmd_check_stop_to_fabric(cmd);
2147	return;
2148
2149queue_full:
2150	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2151		" data_direction: %d\n", cmd, cmd->data_direction);
2152	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2153	transport_handle_queue_full(cmd, cmd->se_dev);
2154}
2155
2156static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2157{
2158	struct scatterlist *sg;
2159	int count;
2160
2161	for_each_sg(sgl, sg, nents, count)
2162		__free_page(sg_page(sg));
2163
2164	kfree(sgl);
2165}
2166
2167static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2168{
2169	/*
2170	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2171	 * emulation, and free + reset pointers if necessary..
2172	 */
2173	if (!cmd->t_data_sg_orig)
2174		return;
2175
2176	kfree(cmd->t_data_sg);
2177	cmd->t_data_sg = cmd->t_data_sg_orig;
2178	cmd->t_data_sg_orig = NULL;
2179	cmd->t_data_nents = cmd->t_data_nents_orig;
2180	cmd->t_data_nents_orig = 0;
2181}
2182
2183static inline void transport_free_pages(struct se_cmd *cmd)
2184{
2185	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2186		/*
2187		 * Release special case READ buffer payload required for
2188		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2189		 */
2190		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2191			transport_free_sgl(cmd->t_bidi_data_sg,
2192					   cmd->t_bidi_data_nents);
2193			cmd->t_bidi_data_sg = NULL;
2194			cmd->t_bidi_data_nents = 0;
2195		}
2196		transport_reset_sgl_orig(cmd);
2197		return;
2198	}
2199	transport_reset_sgl_orig(cmd);
2200
2201	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2202	cmd->t_data_sg = NULL;
2203	cmd->t_data_nents = 0;
2204
2205	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2206	cmd->t_bidi_data_sg = NULL;
2207	cmd->t_bidi_data_nents = 0;
2208
2209	transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2210	cmd->t_prot_sg = NULL;
2211	cmd->t_prot_nents = 0;
2212}
2213
2214/**
2215 * transport_put_cmd - release a reference to a command
2216 * @cmd:       command to release
2217 *
2218 * This routine releases our reference to the command and frees it if possible.
2219 */
2220static int transport_put_cmd(struct se_cmd *cmd)
2221{
2222	BUG_ON(!cmd->se_tfo);
2223	/*
2224	 * If this cmd has been setup with target_get_sess_cmd(), drop
2225	 * the kref and call ->release_cmd() in kref callback.
2226	 */
2227	return target_put_sess_cmd(cmd);
2228}
2229
2230void *transport_kmap_data_sg(struct se_cmd *cmd)
2231{
2232	struct scatterlist *sg = cmd->t_data_sg;
2233	struct page **pages;
2234	int i;
2235
2236	/*
2237	 * We need to take into account a possible offset here for fabrics like
2238	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2239	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2240	 */
2241	if (!cmd->t_data_nents)
2242		return NULL;
2243
2244	BUG_ON(!sg);
2245	if (cmd->t_data_nents == 1)
2246		return kmap(sg_page(sg)) + sg->offset;
2247
2248	/* >1 page. use vmap */
2249	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2250	if (!pages)
2251		return NULL;
2252
2253	/* convert sg[] to pages[] */
2254	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2255		pages[i] = sg_page(sg);
2256	}
2257
2258	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2259	kfree(pages);
2260	if (!cmd->t_data_vmap)
2261		return NULL;
2262
2263	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2264}
2265EXPORT_SYMBOL(transport_kmap_data_sg);
2266
2267void transport_kunmap_data_sg(struct se_cmd *cmd)
2268{
2269	if (!cmd->t_data_nents) {
2270		return;
2271	} else if (cmd->t_data_nents == 1) {
2272		kunmap(sg_page(cmd->t_data_sg));
2273		return;
2274	}
2275
2276	vunmap(cmd->t_data_vmap);
2277	cmd->t_data_vmap = NULL;
2278}
2279EXPORT_SYMBOL(transport_kunmap_data_sg);
2280
2281int
2282target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2283		 bool zero_page)
2284{
2285	struct scatterlist *sg;
2286	struct page *page;
2287	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2288	unsigned int nent;
2289	int i = 0;
2290
2291	nent = DIV_ROUND_UP(length, PAGE_SIZE);
2292	sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2293	if (!sg)
2294		return -ENOMEM;
2295
2296	sg_init_table(sg, nent);
2297
2298	while (length) {
2299		u32 page_len = min_t(u32, length, PAGE_SIZE);
2300		page = alloc_page(GFP_KERNEL | zero_flag);
2301		if (!page)
2302			goto out;
2303
2304		sg_set_page(&sg[i], page, page_len, 0);
2305		length -= page_len;
2306		i++;
2307	}
2308	*sgl = sg;
2309	*nents = nent;
2310	return 0;
2311
2312out:
2313	while (i > 0) {
2314		i--;
2315		__free_page(sg_page(&sg[i]));
2316	}
2317	kfree(sg);
2318	return -ENOMEM;
2319}
2320
2321/*
2322 * Allocate any required resources to execute the command.  For writes we
2323 * might not have the payload yet, so notify the fabric via a call to
2324 * ->write_pending instead. Otherwise place it on the execution queue.
2325 */
2326sense_reason_t
2327transport_generic_new_cmd(struct se_cmd *cmd)
2328{
2329	int ret = 0;
2330	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2331
2332	/*
2333	 * Determine is the TCM fabric module has already allocated physical
2334	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2335	 * beforehand.
2336	 */
2337	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2338	    cmd->data_length) {
2339
2340		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2341		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2342			u32 bidi_length;
2343
2344			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2345				bidi_length = cmd->t_task_nolb *
2346					      cmd->se_dev->dev_attrib.block_size;
2347			else
2348				bidi_length = cmd->data_length;
2349
2350			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2351					       &cmd->t_bidi_data_nents,
2352					       bidi_length, zero_flag);
2353			if (ret < 0)
2354				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2355		}
2356
2357		if (cmd->prot_op != TARGET_PROT_NORMAL) {
2358			ret = target_alloc_sgl(&cmd->t_prot_sg,
2359					       &cmd->t_prot_nents,
2360					       cmd->prot_length, true);
2361			if (ret < 0)
2362				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2363		}
2364
2365		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2366				       cmd->data_length, zero_flag);
2367		if (ret < 0)
2368			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2369	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2370		    cmd->data_length) {
2371		/*
2372		 * Special case for COMPARE_AND_WRITE with fabrics
2373		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2374		 */
2375		u32 caw_length = cmd->t_task_nolb *
2376				 cmd->se_dev->dev_attrib.block_size;
2377
2378		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2379				       &cmd->t_bidi_data_nents,
2380				       caw_length, zero_flag);
2381		if (ret < 0)
2382			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2383	}
2384	/*
2385	 * If this command is not a write we can execute it right here,
2386	 * for write buffers we need to notify the fabric driver first
2387	 * and let it call back once the write buffers are ready.
2388	 */
2389	target_add_to_state_list(cmd);
2390	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2391		target_execute_cmd(cmd);
2392		return 0;
2393	}
2394	transport_cmd_check_stop(cmd, false, true);
2395
2396	ret = cmd->se_tfo->write_pending(cmd);
2397	if (ret == -EAGAIN || ret == -ENOMEM)
2398		goto queue_full;
2399
2400	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2401	WARN_ON(ret);
2402
2403	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2404
2405queue_full:
2406	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2407	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2408	transport_handle_queue_full(cmd, cmd->se_dev);
2409	return 0;
2410}
2411EXPORT_SYMBOL(transport_generic_new_cmd);
2412
2413static void transport_write_pending_qf(struct se_cmd *cmd)
2414{
2415	int ret;
2416
2417	ret = cmd->se_tfo->write_pending(cmd);
2418	if (ret == -EAGAIN || ret == -ENOMEM) {
2419		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2420			 cmd);
2421		transport_handle_queue_full(cmd, cmd->se_dev);
2422	}
2423}
2424
2425static bool
2426__transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2427			   unsigned long *flags);
2428
2429static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2430{
2431	unsigned long flags;
2432
2433	spin_lock_irqsave(&cmd->t_state_lock, flags);
2434	__transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2435	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2436}
2437
2438int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2439{
2440	int ret = 0;
2441	bool aborted = false, tas = false;
2442
2443	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2444		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2445			target_wait_free_cmd(cmd, &aborted, &tas);
2446
2447		if (!aborted || tas)
2448			ret = transport_put_cmd(cmd);
2449	} else {
2450		if (wait_for_tasks)
2451			target_wait_free_cmd(cmd, &aborted, &tas);
2452		/*
2453		 * Handle WRITE failure case where transport_generic_new_cmd()
2454		 * has already added se_cmd to state_list, but fabric has
2455		 * failed command before I/O submission.
2456		 */
2457		if (cmd->state_active)
2458			target_remove_from_state_list(cmd);
2459
2460		if (cmd->se_lun)
2461			transport_lun_remove_cmd(cmd);
2462
2463		if (!aborted || tas)
2464			ret = transport_put_cmd(cmd);
2465	}
2466	/*
2467	 * If the task has been internally aborted due to TMR ABORT_TASK
2468	 * or LUN_RESET, target_core_tmr.c is responsible for performing
2469	 * the remaining calls to target_put_sess_cmd(), and not the
2470	 * callers of this function.
2471	 */
2472	if (aborted) {
2473		pr_debug("Detected CMD_T_ABORTED for ITT: %u\n",
2474			cmd->se_tfo->get_task_tag(cmd));
2475		wait_for_completion(&cmd->cmd_wait_comp);
2476		cmd->se_tfo->release_cmd(cmd);
2477		ret = 1;
2478	}
2479	return ret;
2480}
2481EXPORT_SYMBOL(transport_generic_free_cmd);
2482
2483/* target_get_sess_cmd - Add command to active ->sess_cmd_list
2484 * @se_cmd:	command descriptor to add
2485 * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2486 */
2487int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2488{
2489	struct se_session *se_sess = se_cmd->se_sess;
2490	unsigned long flags;
2491	int ret = 0;
2492
2493	/*
2494	 * Add a second kref if the fabric caller is expecting to handle
2495	 * fabric acknowledgement that requires two target_put_sess_cmd()
2496	 * invocations before se_cmd descriptor release.
2497	 */
2498	if (ack_kref)
2499		kref_get(&se_cmd->cmd_kref);
2500
2501	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2502	if (se_sess->sess_tearing_down) {
2503		ret = -ESHUTDOWN;
2504		goto out;
2505	}
2506	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2507out:
2508	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2509
2510	if (ret && ack_kref)
2511		target_put_sess_cmd(se_cmd);
2512
2513	return ret;
2514}
2515EXPORT_SYMBOL(target_get_sess_cmd);
2516
2517static void target_free_cmd_mem(struct se_cmd *cmd)
2518{
2519	transport_free_pages(cmd);
2520
2521	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2522		core_tmr_release_req(cmd->se_tmr_req);
2523	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2524		kfree(cmd->t_task_cdb);
2525}
2526
2527static void target_release_cmd_kref(struct kref *kref)
2528		__releases(&se_cmd->se_sess->sess_cmd_lock)
2529{
2530	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2531	struct se_session *se_sess = se_cmd->se_sess;
2532	bool fabric_stop;
2533
2534	if (list_empty(&se_cmd->se_cmd_list)) {
2535		spin_unlock(&se_sess->sess_cmd_lock);
2536		target_free_cmd_mem(se_cmd);
2537		se_cmd->se_tfo->release_cmd(se_cmd);
2538		return;
2539	}
2540
2541	spin_lock(&se_cmd->t_state_lock);
2542	fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP);
2543	spin_unlock(&se_cmd->t_state_lock);
2544
2545	if (se_cmd->cmd_wait_set || fabric_stop) {
2546		list_del_init(&se_cmd->se_cmd_list);
2547		spin_unlock(&se_sess->sess_cmd_lock);
2548		target_free_cmd_mem(se_cmd);
2549		complete(&se_cmd->cmd_wait_comp);
2550		return;
2551	}
2552	list_del_init(&se_cmd->se_cmd_list);
2553	spin_unlock(&se_sess->sess_cmd_lock);
2554
2555	target_free_cmd_mem(se_cmd);
2556	se_cmd->se_tfo->release_cmd(se_cmd);
2557}
2558
2559/* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2560 * @se_cmd:	command descriptor to drop
2561 */
2562int target_put_sess_cmd(struct se_cmd *se_cmd)
2563{
2564	struct se_session *se_sess = se_cmd->se_sess;
2565
2566	if (!se_sess) {
2567		target_free_cmd_mem(se_cmd);
2568		se_cmd->se_tfo->release_cmd(se_cmd);
2569		return 1;
2570	}
2571	return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2572			&se_sess->sess_cmd_lock);
2573}
2574EXPORT_SYMBOL(target_put_sess_cmd);
2575
2576/* target_sess_cmd_list_set_waiting - Flag all commands in
2577 *         sess_cmd_list to complete cmd_wait_comp.  Set
2578 *         sess_tearing_down so no more commands are queued.
2579 * @se_sess:	session to flag
2580 */
2581void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2582{
2583	struct se_cmd *se_cmd;
2584	unsigned long flags;
2585	int rc;
2586
2587	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2588	if (se_sess->sess_tearing_down) {
2589		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2590		return;
2591	}
2592	se_sess->sess_tearing_down = 1;
2593	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2594
2595	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list) {
2596		rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2597		if (rc) {
2598			se_cmd->cmd_wait_set = 1;
2599			spin_lock(&se_cmd->t_state_lock);
2600			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2601			spin_unlock(&se_cmd->t_state_lock);
2602		}
2603	}
2604
2605	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2606}
2607EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2608
2609/* target_wait_for_sess_cmds - Wait for outstanding descriptors
2610 * @se_sess:    session to wait for active I/O
2611 */
2612void target_wait_for_sess_cmds(struct se_session *se_sess)
2613{
2614	struct se_cmd *se_cmd, *tmp_cmd;
2615	unsigned long flags;
2616	bool tas;
2617
2618	list_for_each_entry_safe(se_cmd, tmp_cmd,
2619				&se_sess->sess_wait_list, se_cmd_list) {
2620		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2621			" %d\n", se_cmd, se_cmd->t_state,
2622			se_cmd->se_tfo->get_cmd_state(se_cmd));
2623
2624		spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2625		tas = (se_cmd->transport_state & CMD_T_TAS);
2626		spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2627
2628		if (!target_put_sess_cmd(se_cmd)) {
2629			if (tas)
2630				target_put_sess_cmd(se_cmd);
2631		}
2632
2633		wait_for_completion(&se_cmd->cmd_wait_comp);
2634		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2635			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2636			se_cmd->se_tfo->get_cmd_state(se_cmd));
2637
2638		se_cmd->se_tfo->release_cmd(se_cmd);
2639	}
2640
2641	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2642	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2643	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2644
2645}
2646EXPORT_SYMBOL(target_wait_for_sess_cmds);
2647
2648static int transport_clear_lun_ref_thread(void *p)
2649{
2650	struct se_lun *lun = p;
2651
2652	percpu_ref_kill(&lun->lun_ref);
2653
2654	wait_for_completion(&lun->lun_ref_comp);
2655	complete(&lun->lun_shutdown_comp);
2656
2657	return 0;
2658}
2659
2660int transport_clear_lun_ref(struct se_lun *lun)
2661{
2662	struct task_struct *kt;
2663
2664	kt = kthread_run(transport_clear_lun_ref_thread, lun,
2665			"tcm_cl_%u", lun->unpacked_lun);
2666	if (IS_ERR(kt)) {
2667		pr_err("Unable to start clear_lun thread\n");
2668		return PTR_ERR(kt);
2669	}
2670	wait_for_completion(&lun->lun_shutdown_comp);
2671
2672	return 0;
2673}
2674
2675static bool
2676__transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2677			   bool *aborted, bool *tas, unsigned long *flags)
2678	__releases(&cmd->t_state_lock)
2679	__acquires(&cmd->t_state_lock)
2680{
2681
2682	assert_spin_locked(&cmd->t_state_lock);
2683	WARN_ON_ONCE(!irqs_disabled());
2684
2685	if (fabric_stop)
2686		cmd->transport_state |= CMD_T_FABRIC_STOP;
2687
2688	if (cmd->transport_state & CMD_T_ABORTED)
2689		*aborted = true;
2690
2691	if (cmd->transport_state & CMD_T_TAS)
2692		*tas = true;
2693
2694	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2695	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2696		return false;
2697
2698	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2699	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2700		return false;
2701
2702	if (!(cmd->transport_state & CMD_T_ACTIVE))
2703		return false;
2704
2705	if (fabric_stop && *aborted)
2706		return false;
2707
2708	cmd->transport_state |= CMD_T_STOP;
2709
2710	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2711		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2712		cmd, cmd->se_tfo->get_task_tag(cmd),
2713		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2714
2715	spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2716
2717	wait_for_completion(&cmd->t_transport_stop_comp);
2718
2719	spin_lock_irqsave(&cmd->t_state_lock, *flags);
2720	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2721
2722	pr_debug("wait_for_tasks: Stopped wait_for_completion("
2723		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2724		cmd->se_tfo->get_task_tag(cmd));
2725
2726	return true;
2727}
2728
2729/**
2730 * transport_wait_for_tasks - wait for completion to occur
2731 * @cmd:	command to wait
2732 *
2733 * Called from frontend fabric context to wait for storage engine
2734 * to pause and/or release frontend generated struct se_cmd.
2735 */
2736bool transport_wait_for_tasks(struct se_cmd *cmd)
2737{
2738	unsigned long flags;
2739	bool ret, aborted = false, tas = false;
2740
2741	spin_lock_irqsave(&cmd->t_state_lock, flags);
2742	ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2743	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2744
2745	return ret;
2746}
2747EXPORT_SYMBOL(transport_wait_for_tasks);
2748
2749static int transport_get_sense_codes(
2750	struct se_cmd *cmd,
2751	u8 *asc,
2752	u8 *ascq)
2753{
2754	*asc = cmd->scsi_asc;
2755	*ascq = cmd->scsi_ascq;
2756
2757	return 0;
2758}
2759
2760static
2761void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
2762{
2763	/* Place failed LBA in sense data information descriptor 0. */
2764	buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
2765	buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
2766	buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
2767	buffer[SPC_VALIDITY_OFFSET] = 0x80;
2768
2769	/* Descriptor Information: failing sector */
2770	put_unaligned_be64(bad_sector, &buffer[12]);
2771}
2772
2773int
2774transport_send_check_condition_and_sense(struct se_cmd *cmd,
2775		sense_reason_t reason, int from_transport)
2776{
2777	unsigned char *buffer = cmd->sense_buffer;
2778	unsigned long flags;
2779	u8 asc = 0, ascq = 0;
2780
2781	spin_lock_irqsave(&cmd->t_state_lock, flags);
2782	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2783		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2784		return 0;
2785	}
2786	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2787	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2788
2789	if (!reason && from_transport)
2790		goto after_reason;
2791
2792	if (!from_transport)
2793		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2794
2795	/*
2796	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2797	 * SENSE KEY values from include/scsi/scsi.h
2798	 */
2799	switch (reason) {
2800	case TCM_NO_SENSE:
2801		/* CURRENT ERROR */
2802		buffer[0] = 0x70;
2803		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2804		/* Not Ready */
2805		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2806		/* NO ADDITIONAL SENSE INFORMATION */
2807		buffer[SPC_ASC_KEY_OFFSET] = 0;
2808		buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2809		break;
2810	case TCM_NON_EXISTENT_LUN:
2811		/* CURRENT ERROR */
2812		buffer[0] = 0x70;
2813		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2814		/* ILLEGAL REQUEST */
2815		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2816		/* LOGICAL UNIT NOT SUPPORTED */
2817		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2818		break;
2819	case TCM_UNSUPPORTED_SCSI_OPCODE:
2820	case TCM_SECTOR_COUNT_TOO_MANY:
2821		/* CURRENT ERROR */
2822		buffer[0] = 0x70;
2823		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2824		/* ILLEGAL REQUEST */
2825		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2826		/* INVALID COMMAND OPERATION CODE */
2827		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2828		break;
2829	case TCM_UNKNOWN_MODE_PAGE:
2830		/* CURRENT ERROR */
2831		buffer[0] = 0x70;
2832		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2833		/* ILLEGAL REQUEST */
2834		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2835		/* INVALID FIELD IN CDB */
2836		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2837		break;
2838	case TCM_CHECK_CONDITION_ABORT_CMD:
2839		/* CURRENT ERROR */
2840		buffer[0] = 0x70;
2841		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2842		/* ABORTED COMMAND */
2843		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2844		/* BUS DEVICE RESET FUNCTION OCCURRED */
2845		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2846		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2847		break;
2848	case TCM_INCORRECT_AMOUNT_OF_DATA:
2849		/* CURRENT ERROR */
2850		buffer[0] = 0x70;
2851		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2852		/* ABORTED COMMAND */
2853		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2854		/* WRITE ERROR */
2855		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2856		/* NOT ENOUGH UNSOLICITED DATA */
2857		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2858		break;
2859	case TCM_INVALID_CDB_FIELD:
2860		/* CURRENT ERROR */
2861		buffer[0] = 0x70;
2862		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2863		/* ILLEGAL REQUEST */
2864		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2865		/* INVALID FIELD IN CDB */
2866		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2867		break;
2868	case TCM_INVALID_PARAMETER_LIST:
2869		/* CURRENT ERROR */
2870		buffer[0] = 0x70;
2871		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2872		/* ILLEGAL REQUEST */
2873		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2874		/* INVALID FIELD IN PARAMETER LIST */
2875		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2876		break;
2877	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2878		/* CURRENT ERROR */
2879		buffer[0] = 0x70;
2880		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2881		/* ILLEGAL REQUEST */
2882		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2883		/* PARAMETER LIST LENGTH ERROR */
2884		buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2885		break;
2886	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2887		/* CURRENT ERROR */
2888		buffer[0] = 0x70;
2889		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2890		/* ABORTED COMMAND */
2891		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2892		/* WRITE ERROR */
2893		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2894		/* UNEXPECTED_UNSOLICITED_DATA */
2895		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2896		break;
2897	case TCM_SERVICE_CRC_ERROR:
2898		/* CURRENT ERROR */
2899		buffer[0] = 0x70;
2900		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2901		/* ABORTED COMMAND */
2902		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2903		/* PROTOCOL SERVICE CRC ERROR */
2904		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2905		/* N/A */
2906		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2907		break;
2908	case TCM_SNACK_REJECTED:
2909		/* CURRENT ERROR */
2910		buffer[0] = 0x70;
2911		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2912		/* ABORTED COMMAND */
2913		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2914		/* READ ERROR */
2915		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2916		/* FAILED RETRANSMISSION REQUEST */
2917		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2918		break;
2919	case TCM_WRITE_PROTECTED:
2920		/* CURRENT ERROR */
2921		buffer[0] = 0x70;
2922		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2923		/* DATA PROTECT */
2924		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2925		/* WRITE PROTECTED */
2926		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2927		break;
2928	case TCM_ADDRESS_OUT_OF_RANGE:
2929		/* CURRENT ERROR */
2930		buffer[0] = 0x70;
2931		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2932		/* ILLEGAL REQUEST */
2933		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2934		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2935		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2936		break;
2937	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2938		/* CURRENT ERROR */
2939		buffer[0] = 0x70;
2940		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2941		/* UNIT ATTENTION */
2942		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2943		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2944		buffer[SPC_ASC_KEY_OFFSET] = asc;
2945		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2946		break;
2947	case TCM_CHECK_CONDITION_NOT_READY:
2948		/* CURRENT ERROR */
2949		buffer[0] = 0x70;
2950		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2951		/* Not Ready */
2952		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2953		transport_get_sense_codes(cmd, &asc, &ascq);
2954		buffer[SPC_ASC_KEY_OFFSET] = asc;
2955		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2956		break;
2957	case TCM_MISCOMPARE_VERIFY:
2958		/* CURRENT ERROR */
2959		buffer[0] = 0x70;
2960		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2961		buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2962		/* MISCOMPARE DURING VERIFY OPERATION */
2963		buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2964		buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2965		break;
2966	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2967		/* CURRENT ERROR */
2968		buffer[0] = 0x70;
2969		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2970		/* ILLEGAL REQUEST */
2971		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2972		/* LOGICAL BLOCK GUARD CHECK FAILED */
2973		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2974		buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
2975		transport_err_sector_info(buffer, cmd->bad_sector);
2976		break;
2977	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2978		/* CURRENT ERROR */
2979		buffer[0] = 0x70;
2980		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2981		/* ILLEGAL REQUEST */
2982		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2983		/* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2984		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2985		buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
2986		transport_err_sector_info(buffer, cmd->bad_sector);
2987		break;
2988	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2989		/* CURRENT ERROR */
2990		buffer[0] = 0x70;
2991		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2992		/* ILLEGAL REQUEST */
2993		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2994		/* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2995		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2996		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2997		transport_err_sector_info(buffer, cmd->bad_sector);
2998		break;
2999	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
3000	default:
3001		/* CURRENT ERROR */
3002		buffer[0] = 0x70;
3003		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
3004		/*
3005		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
3006		 * Solaris initiators.  Returning NOT READY instead means the
3007		 * operations will be retried a finite number of times and we
3008		 * can survive intermittent errors.
3009		 */
3010		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
3011		/* LOGICAL UNIT COMMUNICATION FAILURE */
3012		buffer[SPC_ASC_KEY_OFFSET] = 0x08;
3013		break;
3014	}
3015	/*
3016	 * This code uses linux/include/scsi/scsi.h SAM status codes!
3017	 */
3018	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3019	/*
3020	 * Automatically padded, this value is encoded in the fabric's
3021	 * data_length response PDU containing the SCSI defined sense data.
3022	 */
3023	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3024
3025after_reason:
3026	trace_target_cmd_complete(cmd);
3027	return cmd->se_tfo->queue_status(cmd);
3028}
3029EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3030
3031static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3032	__releases(&cmd->t_state_lock)
3033	__acquires(&cmd->t_state_lock)
3034{
3035	assert_spin_locked(&cmd->t_state_lock);
3036	WARN_ON_ONCE(!irqs_disabled());
3037
3038	if (!(cmd->transport_state & CMD_T_ABORTED))
3039		return 0;
3040
3041	/*
3042	 * If cmd has been aborted but either no status is to be sent or it has
3043	 * already been sent, just return
3044	 */
3045	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3046		if (send_status)
3047			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3048		return 1;
3049	}
3050
3051	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3052		" 0x%02x ITT: 0x%08x\n", cmd->t_task_cdb[0],
3053		cmd->se_tfo->get_task_tag(cmd));
3054
3055	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3056	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3057	trace_target_cmd_complete(cmd);
3058
3059	spin_unlock_irq(&cmd->t_state_lock);
3060	cmd->se_tfo->queue_status(cmd);
3061	spin_lock_irq(&cmd->t_state_lock);
3062
3063	return 1;
3064}
3065
3066int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3067{
3068	int ret;
3069
3070	spin_lock_irq(&cmd->t_state_lock);
3071	ret = __transport_check_aborted_status(cmd, send_status);
3072	spin_unlock_irq(&cmd->t_state_lock);
3073
3074	return ret;
3075}
3076EXPORT_SYMBOL(transport_check_aborted_status);
3077
3078void transport_send_task_abort(struct se_cmd *cmd)
3079{
3080	unsigned long flags;
3081
3082	spin_lock_irqsave(&cmd->t_state_lock, flags);
3083	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3084		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3085		return;
3086	}
3087	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3088
3089	/*
3090	 * If there are still expected incoming fabric WRITEs, we wait
3091	 * until until they have completed before sending a TASK_ABORTED
3092	 * response.  This response with TASK_ABORTED status will be
3093	 * queued back to fabric module by transport_check_aborted_status().
3094	 */
3095	if (cmd->data_direction == DMA_TO_DEVICE) {
3096		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3097			spin_lock_irqsave(&cmd->t_state_lock, flags);
3098			if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3099				spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3100				goto send_abort;
3101			}
3102			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3103			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3104			return;
3105		}
3106	}
3107send_abort:
3108	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3109
3110	transport_lun_remove_cmd(cmd);
3111
3112	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
3113		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
3114		cmd->se_tfo->get_task_tag(cmd));
3115
3116	trace_target_cmd_complete(cmd);
3117	cmd->se_tfo->queue_status(cmd);
3118}
3119
3120static void target_tmr_work(struct work_struct *work)
3121{
3122	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3123	struct se_device *dev = cmd->se_dev;
3124	struct se_tmr_req *tmr = cmd->se_tmr_req;
3125	unsigned long flags;
3126	int ret;
3127
3128	spin_lock_irqsave(&cmd->t_state_lock, flags);
3129	if (cmd->transport_state & CMD_T_ABORTED) {
3130		tmr->response = TMR_FUNCTION_REJECTED;
3131		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3132		goto check_stop;
3133	}
3134	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3135
3136	switch (tmr->function) {
3137	case TMR_ABORT_TASK:
3138		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3139		break;
3140	case TMR_ABORT_TASK_SET:
3141	case TMR_CLEAR_ACA:
3142	case TMR_CLEAR_TASK_SET:
3143		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3144		break;
3145	case TMR_LUN_RESET:
3146		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3147		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3148					 TMR_FUNCTION_REJECTED;
3149		break;
3150	case TMR_TARGET_WARM_RESET:
3151		tmr->response = TMR_FUNCTION_REJECTED;
3152		break;
3153	case TMR_TARGET_COLD_RESET:
3154		tmr->response = TMR_FUNCTION_REJECTED;
3155		break;
3156	default:
3157		pr_err("Uknown TMR function: 0x%02x.\n",
3158				tmr->function);
3159		tmr->response = TMR_FUNCTION_REJECTED;
3160		break;
3161	}
3162
3163	spin_lock_irqsave(&cmd->t_state_lock, flags);
3164	if (cmd->transport_state & CMD_T_ABORTED) {
3165		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3166		goto check_stop;
3167	}
3168	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3169	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3170
3171	cmd->se_tfo->queue_tm_rsp(cmd);
3172
3173check_stop:
3174	transport_cmd_check_stop_to_fabric(cmd);
3175}
3176
3177int transport_generic_handle_tmr(
3178	struct se_cmd *cmd)
3179{
3180	unsigned long flags;
3181
3182	spin_lock_irqsave(&cmd->t_state_lock, flags);
3183	cmd->transport_state |= CMD_T_ACTIVE;
3184	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3185
3186	INIT_WORK(&cmd->work, target_tmr_work);
3187	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3188	return 0;
3189}
3190EXPORT_SYMBOL(transport_generic_handle_tmr);
3191