4653d826e595ac3f1f02f73806c8bb67a6151dac
[firefly-linux-kernel-4.4.55.git] / drivers / target / target_core_transport.c
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
57 static struct workqueue_struct *target_completion_wq;
58 static struct kmem_cache *se_sess_cache;
59 struct kmem_cache *se_ua_cache;
60 struct kmem_cache *t10_pr_reg_cache;
61 struct kmem_cache *t10_alua_lu_gp_cache;
62 struct kmem_cache *t10_alua_lu_gp_mem_cache;
63 struct kmem_cache *t10_alua_tg_pt_gp_cache;
64 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
65 struct kmem_cache *t10_alua_lba_map_cache;
66 struct kmem_cache *t10_alua_lba_map_mem_cache;
67
68 static void transport_complete_task_attr(struct se_cmd *cmd);
69 static void transport_handle_queue_full(struct se_cmd *cmd,
70                 struct se_device *dev);
71 static int transport_put_cmd(struct se_cmd *cmd);
72 static void target_complete_ok_work(struct work_struct *work);
73
74 int 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
159 out_free_lba_map_mem_cache:
160         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
161 out_free_lba_map_cache:
162         kmem_cache_destroy(t10_alua_lba_map_cache);
163 out_free_tg_pt_gp_mem_cache:
164         kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
165 out_free_tg_pt_gp_cache:
166         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
167 out_free_lu_gp_mem_cache:
168         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
169 out_free_lu_gp_cache:
170         kmem_cache_destroy(t10_alua_lu_gp_cache);
171 out_free_pr_reg_cache:
172         kmem_cache_destroy(t10_pr_reg_cache);
173 out_free_ua_cache:
174         kmem_cache_destroy(se_ua_cache);
175 out_free_sess_cache:
176         kmem_cache_destroy(se_sess_cache);
177 out:
178         return -ENOMEM;
179 }
180
181 void 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. */
196 static DEFINE_SPINLOCK(scsi_mib_index_lock);
197 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
198
199 /*
200  * Allocate a new row index for the entry type specified
201  */
202 u32 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
215 void 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         sub_api_initialized = 1;
236 }
237
238 struct se_session *transport_init_session(void)
239 {
240         struct se_session *se_sess;
241
242         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
243         if (!se_sess) {
244                 pr_err("Unable to allocate struct se_session from"
245                                 " se_sess_cache\n");
246                 return ERR_PTR(-ENOMEM);
247         }
248         INIT_LIST_HEAD(&se_sess->sess_list);
249         INIT_LIST_HEAD(&se_sess->sess_acl_list);
250         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
251         INIT_LIST_HEAD(&se_sess->sess_wait_list);
252         spin_lock_init(&se_sess->sess_cmd_lock);
253         kref_init(&se_sess->sess_kref);
254
255         return se_sess;
256 }
257 EXPORT_SYMBOL(transport_init_session);
258
259 int transport_alloc_session_tags(struct se_session *se_sess,
260                                  unsigned int tag_num, unsigned int tag_size)
261 {
262         int rc;
263
264         se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
265                                         GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
266         if (!se_sess->sess_cmd_map) {
267                 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
268                 if (!se_sess->sess_cmd_map) {
269                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
270                         return -ENOMEM;
271                 }
272         }
273
274         rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
275         if (rc < 0) {
276                 pr_err("Unable to init se_sess->sess_tag_pool,"
277                         " tag_num: %u\n", tag_num);
278                 if (is_vmalloc_addr(se_sess->sess_cmd_map))
279                         vfree(se_sess->sess_cmd_map);
280                 else
281                         kfree(se_sess->sess_cmd_map);
282                 se_sess->sess_cmd_map = NULL;
283                 return -ENOMEM;
284         }
285
286         return 0;
287 }
288 EXPORT_SYMBOL(transport_alloc_session_tags);
289
290 struct se_session *transport_init_session_tags(unsigned int tag_num,
291                                                unsigned int tag_size)
292 {
293         struct se_session *se_sess;
294         int rc;
295
296         se_sess = transport_init_session();
297         if (IS_ERR(se_sess))
298                 return se_sess;
299
300         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
301         if (rc < 0) {
302                 transport_free_session(se_sess);
303                 return ERR_PTR(-ENOMEM);
304         }
305
306         return se_sess;
307 }
308 EXPORT_SYMBOL(transport_init_session_tags);
309
310 /*
311  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
312  */
313 void __transport_register_session(
314         struct se_portal_group *se_tpg,
315         struct se_node_acl *se_nacl,
316         struct se_session *se_sess,
317         void *fabric_sess_ptr)
318 {
319         unsigned char buf[PR_REG_ISID_LEN];
320
321         se_sess->se_tpg = se_tpg;
322         se_sess->fabric_sess_ptr = fabric_sess_ptr;
323         /*
324          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
325          *
326          * Only set for struct se_session's that will actually be moving I/O.
327          * eg: *NOT* discovery sessions.
328          */
329         if (se_nacl) {
330                 /*
331                  * If the fabric module supports an ISID based TransportID,
332                  * save this value in binary from the fabric I_T Nexus now.
333                  */
334                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
335                         memset(&buf[0], 0, PR_REG_ISID_LEN);
336                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
337                                         &buf[0], PR_REG_ISID_LEN);
338                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
339                 }
340                 kref_get(&se_nacl->acl_kref);
341
342                 spin_lock_irq(&se_nacl->nacl_sess_lock);
343                 /*
344                  * The se_nacl->nacl_sess pointer will be set to the
345                  * last active I_T Nexus for each struct se_node_acl.
346                  */
347                 se_nacl->nacl_sess = se_sess;
348
349                 list_add_tail(&se_sess->sess_acl_list,
350                               &se_nacl->acl_sess_list);
351                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
352         }
353         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
354
355         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
356                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
357 }
358 EXPORT_SYMBOL(__transport_register_session);
359
360 void transport_register_session(
361         struct se_portal_group *se_tpg,
362         struct se_node_acl *se_nacl,
363         struct se_session *se_sess,
364         void *fabric_sess_ptr)
365 {
366         unsigned long flags;
367
368         spin_lock_irqsave(&se_tpg->session_lock, flags);
369         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
370         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
371 }
372 EXPORT_SYMBOL(transport_register_session);
373
374 static void target_release_session(struct kref *kref)
375 {
376         struct se_session *se_sess = container_of(kref,
377                         struct se_session, sess_kref);
378         struct se_portal_group *se_tpg = se_sess->se_tpg;
379
380         se_tpg->se_tpg_tfo->close_session(se_sess);
381 }
382
383 void target_get_session(struct se_session *se_sess)
384 {
385         kref_get(&se_sess->sess_kref);
386 }
387 EXPORT_SYMBOL(target_get_session);
388
389 void target_put_session(struct se_session *se_sess)
390 {
391         struct se_portal_group *tpg = se_sess->se_tpg;
392
393         if (tpg->se_tpg_tfo->put_session != NULL) {
394                 tpg->se_tpg_tfo->put_session(se_sess);
395                 return;
396         }
397         kref_put(&se_sess->sess_kref, target_release_session);
398 }
399 EXPORT_SYMBOL(target_put_session);
400
401 static void target_complete_nacl(struct kref *kref)
402 {
403         struct se_node_acl *nacl = container_of(kref,
404                                 struct se_node_acl, acl_kref);
405
406         complete(&nacl->acl_free_comp);
407 }
408
409 void target_put_nacl(struct se_node_acl *nacl)
410 {
411         kref_put(&nacl->acl_kref, target_complete_nacl);
412 }
413
414 void transport_deregister_session_configfs(struct se_session *se_sess)
415 {
416         struct se_node_acl *se_nacl;
417         unsigned long flags;
418         /*
419          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
420          */
421         se_nacl = se_sess->se_node_acl;
422         if (se_nacl) {
423                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
424                 if (se_nacl->acl_stop == 0)
425                         list_del(&se_sess->sess_acl_list);
426                 /*
427                  * If the session list is empty, then clear the pointer.
428                  * Otherwise, set the struct se_session pointer from the tail
429                  * element of the per struct se_node_acl active session list.
430                  */
431                 if (list_empty(&se_nacl->acl_sess_list))
432                         se_nacl->nacl_sess = NULL;
433                 else {
434                         se_nacl->nacl_sess = container_of(
435                                         se_nacl->acl_sess_list.prev,
436                                         struct se_session, sess_acl_list);
437                 }
438                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
439         }
440 }
441 EXPORT_SYMBOL(transport_deregister_session_configfs);
442
443 void transport_free_session(struct se_session *se_sess)
444 {
445         if (se_sess->sess_cmd_map) {
446                 percpu_ida_destroy(&se_sess->sess_tag_pool);
447                 if (is_vmalloc_addr(se_sess->sess_cmd_map))
448                         vfree(se_sess->sess_cmd_map);
449                 else
450                         kfree(se_sess->sess_cmd_map);
451         }
452         kmem_cache_free(se_sess_cache, se_sess);
453 }
454 EXPORT_SYMBOL(transport_free_session);
455
456 void transport_deregister_session(struct se_session *se_sess)
457 {
458         struct se_portal_group *se_tpg = se_sess->se_tpg;
459         struct target_core_fabric_ops *se_tfo;
460         struct se_node_acl *se_nacl;
461         unsigned long flags;
462         bool comp_nacl = true;
463
464         if (!se_tpg) {
465                 transport_free_session(se_sess);
466                 return;
467         }
468         se_tfo = se_tpg->se_tpg_tfo;
469
470         spin_lock_irqsave(&se_tpg->session_lock, flags);
471         list_del(&se_sess->sess_list);
472         se_sess->se_tpg = NULL;
473         se_sess->fabric_sess_ptr = NULL;
474         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
475
476         /*
477          * Determine if we need to do extra work for this initiator node's
478          * struct se_node_acl if it had been previously dynamically generated.
479          */
480         se_nacl = se_sess->se_node_acl;
481
482         spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
483         if (se_nacl && se_nacl->dynamic_node_acl) {
484                 if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
485                         list_del(&se_nacl->acl_list);
486                         se_tpg->num_node_acls--;
487                         spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
488                         core_tpg_wait_for_nacl_pr_ref(se_nacl);
489                         core_free_device_list_for_node(se_nacl, se_tpg);
490                         se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
491
492                         comp_nacl = false;
493                         spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
494                 }
495         }
496         spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
497
498         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
499                 se_tpg->se_tpg_tfo->get_fabric_name());
500         /*
501          * If last kref is dropping now for an explicit NodeACL, awake sleeping
502          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
503          * removal context.
504          */
505         if (se_nacl && comp_nacl == true)
506                 target_put_nacl(se_nacl);
507
508         transport_free_session(se_sess);
509 }
510 EXPORT_SYMBOL(transport_deregister_session);
511
512 /*
513  * Called with cmd->t_state_lock held.
514  */
515 static void target_remove_from_state_list(struct se_cmd *cmd)
516 {
517         struct se_device *dev = cmd->se_dev;
518         unsigned long flags;
519
520         if (!dev)
521                 return;
522
523         if (cmd->transport_state & CMD_T_BUSY)
524                 return;
525
526         spin_lock_irqsave(&dev->execute_task_lock, flags);
527         if (cmd->state_active) {
528                 list_del(&cmd->state_list);
529                 cmd->state_active = false;
530         }
531         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
532 }
533
534 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
535                                     bool write_pending)
536 {
537         unsigned long flags;
538
539         spin_lock_irqsave(&cmd->t_state_lock, flags);
540         if (write_pending)
541                 cmd->t_state = TRANSPORT_WRITE_PENDING;
542
543         if (remove_from_lists) {
544                 target_remove_from_state_list(cmd);
545
546                 /*
547                  * Clear struct se_cmd->se_lun before the handoff to FE.
548                  */
549                 cmd->se_lun = NULL;
550         }
551
552         /*
553          * Determine if frontend context caller is requesting the stopping of
554          * this command for frontend exceptions.
555          */
556         if (cmd->transport_state & CMD_T_STOP) {
557                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
558                         __func__, __LINE__,
559                         cmd->se_tfo->get_task_tag(cmd));
560
561                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
562
563                 complete(&cmd->t_transport_stop_comp);
564                 return 1;
565         }
566
567         cmd->transport_state &= ~CMD_T_ACTIVE;
568         if (remove_from_lists) {
569                 /*
570                  * Some fabric modules like tcm_loop can release
571                  * their internally allocated I/O reference now and
572                  * struct se_cmd now.
573                  *
574                  * Fabric modules are expected to return '1' here if the
575                  * se_cmd being passed is released at this point,
576                  * or zero if not being released.
577                  */
578                 if (cmd->se_tfo->check_stop_free != NULL) {
579                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
580                         return cmd->se_tfo->check_stop_free(cmd);
581                 }
582         }
583
584         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
585         return 0;
586 }
587
588 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
589 {
590         return transport_cmd_check_stop(cmd, true, false);
591 }
592
593 static void transport_lun_remove_cmd(struct se_cmd *cmd)
594 {
595         struct se_lun *lun = cmd->se_lun;
596
597         if (!lun)
598                 return;
599
600         if (cmpxchg(&cmd->lun_ref_active, true, false))
601                 percpu_ref_put(&lun->lun_ref);
602 }
603
604 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
605 {
606         if (transport_cmd_check_stop_to_fabric(cmd))
607                 return;
608         if (remove)
609                 transport_put_cmd(cmd);
610 }
611
612 static void target_complete_failure_work(struct work_struct *work)
613 {
614         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
615
616         transport_generic_request_failure(cmd,
617                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
618 }
619
620 /*
621  * Used when asking transport to copy Sense Data from the underlying
622  * Linux/SCSI struct scsi_cmnd
623  */
624 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
625 {
626         struct se_device *dev = cmd->se_dev;
627
628         WARN_ON(!cmd->se_lun);
629
630         if (!dev)
631                 return NULL;
632
633         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
634                 return NULL;
635
636         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
637
638         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
639                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
640         return cmd->sense_buffer;
641 }
642
643 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
644 {
645         struct se_device *dev = cmd->se_dev;
646         int success = scsi_status == GOOD;
647         unsigned long flags;
648
649         cmd->scsi_status = scsi_status;
650
651
652         spin_lock_irqsave(&cmd->t_state_lock, flags);
653         cmd->transport_state &= ~CMD_T_BUSY;
654
655         if (dev && dev->transport->transport_complete) {
656                 dev->transport->transport_complete(cmd,
657                                 cmd->t_data_sg,
658                                 transport_get_sense_buffer(cmd));
659                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
660                         success = 1;
661         }
662
663         /*
664          * See if we are waiting to complete for an exception condition.
665          */
666         if (cmd->transport_state & CMD_T_REQUEST_STOP) {
667                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
668                 complete(&cmd->task_stop_comp);
669                 return;
670         }
671
672         /*
673          * Check for case where an explicit ABORT_TASK has been received
674          * and transport_wait_for_tasks() will be waiting for completion..
675          */
676         if (cmd->transport_state & CMD_T_ABORTED &&
677             cmd->transport_state & CMD_T_STOP) {
678                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
679                 complete(&cmd->t_transport_stop_comp);
680                 return;
681         } else if (!success) {
682                 INIT_WORK(&cmd->work, target_complete_failure_work);
683         } else {
684                 INIT_WORK(&cmd->work, target_complete_ok_work);
685         }
686
687         cmd->t_state = TRANSPORT_COMPLETE;
688         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
689         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
690
691         queue_work(target_completion_wq, &cmd->work);
692 }
693 EXPORT_SYMBOL(target_complete_cmd);
694
695 static void target_add_to_state_list(struct se_cmd *cmd)
696 {
697         struct se_device *dev = cmd->se_dev;
698         unsigned long flags;
699
700         spin_lock_irqsave(&dev->execute_task_lock, flags);
701         if (!cmd->state_active) {
702                 list_add_tail(&cmd->state_list, &dev->state_list);
703                 cmd->state_active = true;
704         }
705         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
706 }
707
708 /*
709  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
710  */
711 static void transport_write_pending_qf(struct se_cmd *cmd);
712 static void transport_complete_qf(struct se_cmd *cmd);
713
714 void target_qf_do_work(struct work_struct *work)
715 {
716         struct se_device *dev = container_of(work, struct se_device,
717                                         qf_work_queue);
718         LIST_HEAD(qf_cmd_list);
719         struct se_cmd *cmd, *cmd_tmp;
720
721         spin_lock_irq(&dev->qf_cmd_lock);
722         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
723         spin_unlock_irq(&dev->qf_cmd_lock);
724
725         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
726                 list_del(&cmd->se_qf_node);
727                 atomic_dec(&dev->dev_qf_count);
728                 smp_mb__after_atomic_dec();
729
730                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
731                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
732                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
733                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
734                         : "UNKNOWN");
735
736                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
737                         transport_write_pending_qf(cmd);
738                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
739                         transport_complete_qf(cmd);
740         }
741 }
742
743 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
744 {
745         switch (cmd->data_direction) {
746         case DMA_NONE:
747                 return "NONE";
748         case DMA_FROM_DEVICE:
749                 return "READ";
750         case DMA_TO_DEVICE:
751                 return "WRITE";
752         case DMA_BIDIRECTIONAL:
753                 return "BIDI";
754         default:
755                 break;
756         }
757
758         return "UNKNOWN";
759 }
760
761 void transport_dump_dev_state(
762         struct se_device *dev,
763         char *b,
764         int *bl)
765 {
766         *bl += sprintf(b + *bl, "Status: ");
767         if (dev->export_count)
768                 *bl += sprintf(b + *bl, "ACTIVATED");
769         else
770                 *bl += sprintf(b + *bl, "DEACTIVATED");
771
772         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
773         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
774                 dev->dev_attrib.block_size,
775                 dev->dev_attrib.hw_max_sectors);
776         *bl += sprintf(b + *bl, "        ");
777 }
778
779 void transport_dump_vpd_proto_id(
780         struct t10_vpd *vpd,
781         unsigned char *p_buf,
782         int p_buf_len)
783 {
784         unsigned char buf[VPD_TMP_BUF_SIZE];
785         int len;
786
787         memset(buf, 0, VPD_TMP_BUF_SIZE);
788         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
789
790         switch (vpd->protocol_identifier) {
791         case 0x00:
792                 sprintf(buf+len, "Fibre Channel\n");
793                 break;
794         case 0x10:
795                 sprintf(buf+len, "Parallel SCSI\n");
796                 break;
797         case 0x20:
798                 sprintf(buf+len, "SSA\n");
799                 break;
800         case 0x30:
801                 sprintf(buf+len, "IEEE 1394\n");
802                 break;
803         case 0x40:
804                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
805                                 " Protocol\n");
806                 break;
807         case 0x50:
808                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
809                 break;
810         case 0x60:
811                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
812                 break;
813         case 0x70:
814                 sprintf(buf+len, "Automation/Drive Interface Transport"
815                                 " Protocol\n");
816                 break;
817         case 0x80:
818                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
819                 break;
820         default:
821                 sprintf(buf+len, "Unknown 0x%02x\n",
822                                 vpd->protocol_identifier);
823                 break;
824         }
825
826         if (p_buf)
827                 strncpy(p_buf, buf, p_buf_len);
828         else
829                 pr_debug("%s", buf);
830 }
831
832 void
833 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
834 {
835         /*
836          * Check if the Protocol Identifier Valid (PIV) bit is set..
837          *
838          * from spc3r23.pdf section 7.5.1
839          */
840          if (page_83[1] & 0x80) {
841                 vpd->protocol_identifier = (page_83[0] & 0xf0);
842                 vpd->protocol_identifier_set = 1;
843                 transport_dump_vpd_proto_id(vpd, NULL, 0);
844         }
845 }
846 EXPORT_SYMBOL(transport_set_vpd_proto_id);
847
848 int transport_dump_vpd_assoc(
849         struct t10_vpd *vpd,
850         unsigned char *p_buf,
851         int p_buf_len)
852 {
853         unsigned char buf[VPD_TMP_BUF_SIZE];
854         int ret = 0;
855         int len;
856
857         memset(buf, 0, VPD_TMP_BUF_SIZE);
858         len = sprintf(buf, "T10 VPD Identifier Association: ");
859
860         switch (vpd->association) {
861         case 0x00:
862                 sprintf(buf+len, "addressed logical unit\n");
863                 break;
864         case 0x10:
865                 sprintf(buf+len, "target port\n");
866                 break;
867         case 0x20:
868                 sprintf(buf+len, "SCSI target device\n");
869                 break;
870         default:
871                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
872                 ret = -EINVAL;
873                 break;
874         }
875
876         if (p_buf)
877                 strncpy(p_buf, buf, p_buf_len);
878         else
879                 pr_debug("%s", buf);
880
881         return ret;
882 }
883
884 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
885 {
886         /*
887          * The VPD identification association..
888          *
889          * from spc3r23.pdf Section 7.6.3.1 Table 297
890          */
891         vpd->association = (page_83[1] & 0x30);
892         return transport_dump_vpd_assoc(vpd, NULL, 0);
893 }
894 EXPORT_SYMBOL(transport_set_vpd_assoc);
895
896 int transport_dump_vpd_ident_type(
897         struct t10_vpd *vpd,
898         unsigned char *p_buf,
899         int p_buf_len)
900 {
901         unsigned char buf[VPD_TMP_BUF_SIZE];
902         int ret = 0;
903         int len;
904
905         memset(buf, 0, VPD_TMP_BUF_SIZE);
906         len = sprintf(buf, "T10 VPD Identifier Type: ");
907
908         switch (vpd->device_identifier_type) {
909         case 0x00:
910                 sprintf(buf+len, "Vendor specific\n");
911                 break;
912         case 0x01:
913                 sprintf(buf+len, "T10 Vendor ID based\n");
914                 break;
915         case 0x02:
916                 sprintf(buf+len, "EUI-64 based\n");
917                 break;
918         case 0x03:
919                 sprintf(buf+len, "NAA\n");
920                 break;
921         case 0x04:
922                 sprintf(buf+len, "Relative target port identifier\n");
923                 break;
924         case 0x08:
925                 sprintf(buf+len, "SCSI name string\n");
926                 break;
927         default:
928                 sprintf(buf+len, "Unsupported: 0x%02x\n",
929                                 vpd->device_identifier_type);
930                 ret = -EINVAL;
931                 break;
932         }
933
934         if (p_buf) {
935                 if (p_buf_len < strlen(buf)+1)
936                         return -EINVAL;
937                 strncpy(p_buf, buf, p_buf_len);
938         } else {
939                 pr_debug("%s", buf);
940         }
941
942         return ret;
943 }
944
945 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
946 {
947         /*
948          * The VPD identifier type..
949          *
950          * from spc3r23.pdf Section 7.6.3.1 Table 298
951          */
952         vpd->device_identifier_type = (page_83[1] & 0x0f);
953         return transport_dump_vpd_ident_type(vpd, NULL, 0);
954 }
955 EXPORT_SYMBOL(transport_set_vpd_ident_type);
956
957 int transport_dump_vpd_ident(
958         struct t10_vpd *vpd,
959         unsigned char *p_buf,
960         int p_buf_len)
961 {
962         unsigned char buf[VPD_TMP_BUF_SIZE];
963         int ret = 0;
964
965         memset(buf, 0, VPD_TMP_BUF_SIZE);
966
967         switch (vpd->device_identifier_code_set) {
968         case 0x01: /* Binary */
969                 snprintf(buf, sizeof(buf),
970                         "T10 VPD Binary Device Identifier: %s\n",
971                         &vpd->device_identifier[0]);
972                 break;
973         case 0x02: /* ASCII */
974                 snprintf(buf, sizeof(buf),
975                         "T10 VPD ASCII Device Identifier: %s\n",
976                         &vpd->device_identifier[0]);
977                 break;
978         case 0x03: /* UTF-8 */
979                 snprintf(buf, sizeof(buf),
980                         "T10 VPD UTF-8 Device Identifier: %s\n",
981                         &vpd->device_identifier[0]);
982                 break;
983         default:
984                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
985                         " 0x%02x", vpd->device_identifier_code_set);
986                 ret = -EINVAL;
987                 break;
988         }
989
990         if (p_buf)
991                 strncpy(p_buf, buf, p_buf_len);
992         else
993                 pr_debug("%s", buf);
994
995         return ret;
996 }
997
998 int
999 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1000 {
1001         static const char hex_str[] = "0123456789abcdef";
1002         int j = 0, i = 4; /* offset to start of the identifier */
1003
1004         /*
1005          * The VPD Code Set (encoding)
1006          *
1007          * from spc3r23.pdf Section 7.6.3.1 Table 296
1008          */
1009         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1010         switch (vpd->device_identifier_code_set) {
1011         case 0x01: /* Binary */
1012                 vpd->device_identifier[j++] =
1013                                 hex_str[vpd->device_identifier_type];
1014                 while (i < (4 + page_83[3])) {
1015                         vpd->device_identifier[j++] =
1016                                 hex_str[(page_83[i] & 0xf0) >> 4];
1017                         vpd->device_identifier[j++] =
1018                                 hex_str[page_83[i] & 0x0f];
1019                         i++;
1020                 }
1021                 break;
1022         case 0x02: /* ASCII */
1023         case 0x03: /* UTF-8 */
1024                 while (i < (4 + page_83[3]))
1025                         vpd->device_identifier[j++] = page_83[i++];
1026                 break;
1027         default:
1028                 break;
1029         }
1030
1031         return transport_dump_vpd_ident(vpd, NULL, 0);
1032 }
1033 EXPORT_SYMBOL(transport_set_vpd_ident);
1034
1035 sense_reason_t
1036 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1037 {
1038         struct se_device *dev = cmd->se_dev;
1039
1040         if (cmd->unknown_data_length) {
1041                 cmd->data_length = size;
1042         } else if (size != cmd->data_length) {
1043                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1044                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1045                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1046                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1047
1048                 if (cmd->data_direction == DMA_TO_DEVICE) {
1049                         pr_err("Rejecting underflow/overflow"
1050                                         " WRITE data\n");
1051                         return TCM_INVALID_CDB_FIELD;
1052                 }
1053                 /*
1054                  * Reject READ_* or WRITE_* with overflow/underflow for
1055                  * type SCF_SCSI_DATA_CDB.
1056                  */
1057                 if (dev->dev_attrib.block_size != 512)  {
1058                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1059                                 " CDB on non 512-byte sector setup subsystem"
1060                                 " plugin: %s\n", dev->transport->name);
1061                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1062                         return TCM_INVALID_CDB_FIELD;
1063                 }
1064                 /*
1065                  * For the overflow case keep the existing fabric provided
1066                  * ->data_length.  Otherwise for the underflow case, reset
1067                  * ->data_length to the smaller SCSI expected data transfer
1068                  * length.
1069                  */
1070                 if (size > cmd->data_length) {
1071                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1072                         cmd->residual_count = (size - cmd->data_length);
1073                 } else {
1074                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1075                         cmd->residual_count = (cmd->data_length - size);
1076                         cmd->data_length = size;
1077                 }
1078         }
1079
1080         return 0;
1081
1082 }
1083
1084 /*
1085  * Used by fabric modules containing a local struct se_cmd within their
1086  * fabric dependent per I/O descriptor.
1087  */
1088 void transport_init_se_cmd(
1089         struct se_cmd *cmd,
1090         struct target_core_fabric_ops *tfo,
1091         struct se_session *se_sess,
1092         u32 data_length,
1093         int data_direction,
1094         int task_attr,
1095         unsigned char *sense_buffer)
1096 {
1097         INIT_LIST_HEAD(&cmd->se_delayed_node);
1098         INIT_LIST_HEAD(&cmd->se_qf_node);
1099         INIT_LIST_HEAD(&cmd->se_cmd_list);
1100         INIT_LIST_HEAD(&cmd->state_list);
1101         init_completion(&cmd->t_transport_stop_comp);
1102         init_completion(&cmd->cmd_wait_comp);
1103         init_completion(&cmd->task_stop_comp);
1104         spin_lock_init(&cmd->t_state_lock);
1105         cmd->transport_state = CMD_T_DEV_ACTIVE;
1106
1107         cmd->se_tfo = tfo;
1108         cmd->se_sess = se_sess;
1109         cmd->data_length = data_length;
1110         cmd->data_direction = data_direction;
1111         cmd->sam_task_attr = task_attr;
1112         cmd->sense_buffer = sense_buffer;
1113
1114         cmd->state_active = false;
1115 }
1116 EXPORT_SYMBOL(transport_init_se_cmd);
1117
1118 static sense_reason_t
1119 transport_check_alloc_task_attr(struct se_cmd *cmd)
1120 {
1121         struct se_device *dev = cmd->se_dev;
1122
1123         /*
1124          * Check if SAM Task Attribute emulation is enabled for this
1125          * struct se_device storage object
1126          */
1127         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1128                 return 0;
1129
1130         if (cmd->sam_task_attr == MSG_ACA_TAG) {
1131                 pr_debug("SAM Task Attribute ACA"
1132                         " emulation is not supported\n");
1133                 return TCM_INVALID_CDB_FIELD;
1134         }
1135         /*
1136          * Used to determine when ORDERED commands should go from
1137          * Dormant to Active status.
1138          */
1139         cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1140         smp_mb__after_atomic_inc();
1141         pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1142                         cmd->se_ordered_id, cmd->sam_task_attr,
1143                         dev->transport->name);
1144         return 0;
1145 }
1146
1147 sense_reason_t
1148 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1149 {
1150         struct se_device *dev = cmd->se_dev;
1151         sense_reason_t ret;
1152
1153         /*
1154          * Ensure that the received CDB is less than the max (252 + 8) bytes
1155          * for VARIABLE_LENGTH_CMD
1156          */
1157         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1158                 pr_err("Received SCSI CDB with command_size: %d that"
1159                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1160                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1161                 return TCM_INVALID_CDB_FIELD;
1162         }
1163         /*
1164          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1165          * allocate the additional extended CDB buffer now..  Otherwise
1166          * setup the pointer from __t_task_cdb to t_task_cdb.
1167          */
1168         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1169                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1170                                                 GFP_KERNEL);
1171                 if (!cmd->t_task_cdb) {
1172                         pr_err("Unable to allocate cmd->t_task_cdb"
1173                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1174                                 scsi_command_size(cdb),
1175                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1176                         return TCM_OUT_OF_RESOURCES;
1177                 }
1178         } else
1179                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1180         /*
1181          * Copy the original CDB into cmd->
1182          */
1183         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1184
1185         trace_target_sequencer_start(cmd);
1186
1187         /*
1188          * Check for an existing UNIT ATTENTION condition
1189          */
1190         ret = target_scsi3_ua_check(cmd);
1191         if (ret)
1192                 return ret;
1193
1194         ret = target_alua_state_check(cmd);
1195         if (ret)
1196                 return ret;
1197
1198         ret = target_check_reservation(cmd);
1199         if (ret) {
1200                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1201                 return ret;
1202         }
1203
1204         ret = dev->transport->parse_cdb(cmd);
1205         if (ret)
1206                 return ret;
1207
1208         ret = transport_check_alloc_task_attr(cmd);
1209         if (ret)
1210                 return ret;
1211
1212         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1213
1214         spin_lock(&cmd->se_lun->lun_sep_lock);
1215         if (cmd->se_lun->lun_sep)
1216                 cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1217         spin_unlock(&cmd->se_lun->lun_sep_lock);
1218         return 0;
1219 }
1220 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1221
1222 /*
1223  * Used by fabric module frontends to queue tasks directly.
1224  * Many only be used from process context only
1225  */
1226 int transport_handle_cdb_direct(
1227         struct se_cmd *cmd)
1228 {
1229         sense_reason_t ret;
1230
1231         if (!cmd->se_lun) {
1232                 dump_stack();
1233                 pr_err("cmd->se_lun is NULL\n");
1234                 return -EINVAL;
1235         }
1236         if (in_interrupt()) {
1237                 dump_stack();
1238                 pr_err("transport_generic_handle_cdb cannot be called"
1239                                 " from interrupt context\n");
1240                 return -EINVAL;
1241         }
1242         /*
1243          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1244          * outstanding descriptors are handled correctly during shutdown via
1245          * transport_wait_for_tasks()
1246          *
1247          * Also, we don't take cmd->t_state_lock here as we only expect
1248          * this to be called for initial descriptor submission.
1249          */
1250         cmd->t_state = TRANSPORT_NEW_CMD;
1251         cmd->transport_state |= CMD_T_ACTIVE;
1252
1253         /*
1254          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1255          * so follow TRANSPORT_NEW_CMD processing thread context usage
1256          * and call transport_generic_request_failure() if necessary..
1257          */
1258         ret = transport_generic_new_cmd(cmd);
1259         if (ret)
1260                 transport_generic_request_failure(cmd, ret);
1261         return 0;
1262 }
1263 EXPORT_SYMBOL(transport_handle_cdb_direct);
1264
1265 sense_reason_t
1266 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1267                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1268 {
1269         if (!sgl || !sgl_count)
1270                 return 0;
1271
1272         /*
1273          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1274          * scatterlists already have been set to follow what the fabric
1275          * passes for the original expected data transfer length.
1276          */
1277         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1278                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1279                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1280                 return TCM_INVALID_CDB_FIELD;
1281         }
1282
1283         cmd->t_data_sg = sgl;
1284         cmd->t_data_nents = sgl_count;
1285
1286         if (sgl_bidi && sgl_bidi_count) {
1287                 cmd->t_bidi_data_sg = sgl_bidi;
1288                 cmd->t_bidi_data_nents = sgl_bidi_count;
1289         }
1290         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1291         return 0;
1292 }
1293
1294 /*
1295  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1296  *                       se_cmd + use pre-allocated SGL memory.
1297  *
1298  * @se_cmd: command descriptor to submit
1299  * @se_sess: associated se_sess for endpoint
1300  * @cdb: pointer to SCSI CDB
1301  * @sense: pointer to SCSI sense buffer
1302  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1303  * @data_length: fabric expected data transfer length
1304  * @task_addr: SAM task attribute
1305  * @data_dir: DMA data direction
1306  * @flags: flags for command submission from target_sc_flags_tables
1307  * @sgl: struct scatterlist memory for unidirectional mapping
1308  * @sgl_count: scatterlist count for unidirectional mapping
1309  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1310  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1311  * @sgl_prot: struct scatterlist memory protection information
1312  * @sgl_prot_count: scatterlist count for protection information
1313  *
1314  * Returns non zero to signal active I/O shutdown failure.  All other
1315  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1316  * but still return zero here.
1317  *
1318  * This may only be called from process context, and also currently
1319  * assumes internal allocation of fabric payload buffer by target-core.
1320  */
1321 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1322                 unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1323                 u32 data_length, int task_attr, int data_dir, int flags,
1324                 struct scatterlist *sgl, u32 sgl_count,
1325                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1326                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1327 {
1328         struct se_portal_group *se_tpg;
1329         sense_reason_t rc;
1330         int ret;
1331
1332         se_tpg = se_sess->se_tpg;
1333         BUG_ON(!se_tpg);
1334         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1335         BUG_ON(in_interrupt());
1336         /*
1337          * Initialize se_cmd for target operation.  From this point
1338          * exceptions are handled by sending exception status via
1339          * target_core_fabric_ops->queue_status() callback
1340          */
1341         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1342                                 data_length, data_dir, task_attr, sense);
1343         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1344                 se_cmd->unknown_data_length = 1;
1345         /*
1346          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1347          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1348          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1349          * kref_put() to happen during fabric packet acknowledgement.
1350          */
1351         ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1352         if (ret)
1353                 return ret;
1354         /*
1355          * Signal bidirectional data payloads to target-core
1356          */
1357         if (flags & TARGET_SCF_BIDI_OP)
1358                 se_cmd->se_cmd_flags |= SCF_BIDI;
1359         /*
1360          * Locate se_lun pointer and attach it to struct se_cmd
1361          */
1362         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1363         if (rc) {
1364                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1365                 target_put_sess_cmd(se_sess, se_cmd);
1366                 return 0;
1367         }
1368         /*
1369          * Save pointers for SGLs containing protection information,
1370          * if present.
1371          */
1372         if (sgl_prot_count) {
1373                 se_cmd->t_prot_sg = sgl_prot;
1374                 se_cmd->t_prot_nents = sgl_prot_count;
1375         }
1376
1377         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1378         if (rc != 0) {
1379                 transport_generic_request_failure(se_cmd, rc);
1380                 return 0;
1381         }
1382         /*
1383          * When a non zero sgl_count has been passed perform SGL passthrough
1384          * mapping for pre-allocated fabric memory instead of having target
1385          * core perform an internal SGL allocation..
1386          */
1387         if (sgl_count != 0) {
1388                 BUG_ON(!sgl);
1389
1390                 /*
1391                  * A work-around for tcm_loop as some userspace code via
1392                  * scsi-generic do not memset their associated read buffers,
1393                  * so go ahead and do that here for type non-data CDBs.  Also
1394                  * note that this is currently guaranteed to be a single SGL
1395                  * for this case by target core in target_setup_cmd_from_cdb()
1396                  * -> transport_generic_cmd_sequencer().
1397                  */
1398                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1399                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1400                         unsigned char *buf = NULL;
1401
1402                         if (sgl)
1403                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1404
1405                         if (buf) {
1406                                 memset(buf, 0, sgl->length);
1407                                 kunmap(sg_page(sgl));
1408                         }
1409                 }
1410
1411                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1412                                 sgl_bidi, sgl_bidi_count);
1413                 if (rc != 0) {
1414                         transport_generic_request_failure(se_cmd, rc);
1415                         return 0;
1416                 }
1417         }
1418
1419         /*
1420          * Check if we need to delay processing because of ALUA
1421          * Active/NonOptimized primary access state..
1422          */
1423         core_alua_check_nonop_delay(se_cmd);
1424
1425         transport_handle_cdb_direct(se_cmd);
1426         return 0;
1427 }
1428 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1429
1430 /*
1431  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1432  *
1433  * @se_cmd: command descriptor to submit
1434  * @se_sess: associated se_sess for endpoint
1435  * @cdb: pointer to SCSI CDB
1436  * @sense: pointer to SCSI sense buffer
1437  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1438  * @data_length: fabric expected data transfer length
1439  * @task_addr: SAM task attribute
1440  * @data_dir: DMA data direction
1441  * @flags: flags for command submission from target_sc_flags_tables
1442  *
1443  * Returns non zero to signal active I/O shutdown failure.  All other
1444  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1445  * but still return zero here.
1446  *
1447  * This may only be called from process context, and also currently
1448  * assumes internal allocation of fabric payload buffer by target-core.
1449  *
1450  * It also assumes interal target core SGL memory allocation.
1451  */
1452 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1453                 unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1454                 u32 data_length, int task_attr, int data_dir, int flags)
1455 {
1456         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1457                         unpacked_lun, data_length, task_attr, data_dir,
1458                         flags, NULL, 0, NULL, 0, NULL, 0);
1459 }
1460 EXPORT_SYMBOL(target_submit_cmd);
1461
1462 static void target_complete_tmr_failure(struct work_struct *work)
1463 {
1464         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1465
1466         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1467         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1468
1469         transport_cmd_check_stop_to_fabric(se_cmd);
1470 }
1471
1472 /**
1473  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1474  *                     for TMR CDBs
1475  *
1476  * @se_cmd: command descriptor to submit
1477  * @se_sess: associated se_sess for endpoint
1478  * @sense: pointer to SCSI sense buffer
1479  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1480  * @fabric_context: fabric context for TMR req
1481  * @tm_type: Type of TM request
1482  * @gfp: gfp type for caller
1483  * @tag: referenced task tag for TMR_ABORT_TASK
1484  * @flags: submit cmd flags
1485  *
1486  * Callable from all contexts.
1487  **/
1488
1489 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1490                 unsigned char *sense, u32 unpacked_lun,
1491                 void *fabric_tmr_ptr, unsigned char tm_type,
1492                 gfp_t gfp, unsigned int tag, int flags)
1493 {
1494         struct se_portal_group *se_tpg;
1495         int ret;
1496
1497         se_tpg = se_sess->se_tpg;
1498         BUG_ON(!se_tpg);
1499
1500         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1501                               0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1502         /*
1503          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1504          * allocation failure.
1505          */
1506         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1507         if (ret < 0)
1508                 return -ENOMEM;
1509
1510         if (tm_type == TMR_ABORT_TASK)
1511                 se_cmd->se_tmr_req->ref_task_tag = tag;
1512
1513         /* See target_submit_cmd for commentary */
1514         ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1515         if (ret) {
1516                 core_tmr_release_req(se_cmd->se_tmr_req);
1517                 return ret;
1518         }
1519
1520         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1521         if (ret) {
1522                 /*
1523                  * For callback during failure handling, push this work off
1524                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1525                  */
1526                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1527                 schedule_work(&se_cmd->work);
1528                 return 0;
1529         }
1530         transport_generic_handle_tmr(se_cmd);
1531         return 0;
1532 }
1533 EXPORT_SYMBOL(target_submit_tmr);
1534
1535 /*
1536  * If the cmd is active, request it to be stopped and sleep until it
1537  * has completed.
1538  */
1539 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1540 {
1541         bool was_active = false;
1542
1543         if (cmd->transport_state & CMD_T_BUSY) {
1544                 cmd->transport_state |= CMD_T_REQUEST_STOP;
1545                 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1546
1547                 pr_debug("cmd %p waiting to complete\n", cmd);
1548                 wait_for_completion(&cmd->task_stop_comp);
1549                 pr_debug("cmd %p stopped successfully\n", cmd);
1550
1551                 spin_lock_irqsave(&cmd->t_state_lock, *flags);
1552                 cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1553                 cmd->transport_state &= ~CMD_T_BUSY;
1554                 was_active = true;
1555         }
1556
1557         return was_active;
1558 }
1559
1560 /*
1561  * Handle SAM-esque emulation for generic transport request failures.
1562  */
1563 void transport_generic_request_failure(struct se_cmd *cmd,
1564                 sense_reason_t sense_reason)
1565 {
1566         int ret = 0;
1567
1568         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1569                 " CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1570                 cmd->t_task_cdb[0]);
1571         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1572                 cmd->se_tfo->get_cmd_state(cmd),
1573                 cmd->t_state, sense_reason);
1574         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1575                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1576                 (cmd->transport_state & CMD_T_STOP) != 0,
1577                 (cmd->transport_state & CMD_T_SENT) != 0);
1578
1579         /*
1580          * For SAM Task Attribute emulation for failed struct se_cmd
1581          */
1582         transport_complete_task_attr(cmd);
1583         /*
1584          * Handle special case for COMPARE_AND_WRITE failure, where the
1585          * callback is expected to drop the per device ->caw_mutex.
1586          */
1587         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1588              cmd->transport_complete_callback)
1589                 cmd->transport_complete_callback(cmd);
1590
1591         switch (sense_reason) {
1592         case TCM_NON_EXISTENT_LUN:
1593         case TCM_UNSUPPORTED_SCSI_OPCODE:
1594         case TCM_INVALID_CDB_FIELD:
1595         case TCM_INVALID_PARAMETER_LIST:
1596         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1597         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1598         case TCM_UNKNOWN_MODE_PAGE:
1599         case TCM_WRITE_PROTECTED:
1600         case TCM_ADDRESS_OUT_OF_RANGE:
1601         case TCM_CHECK_CONDITION_ABORT_CMD:
1602         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1603         case TCM_CHECK_CONDITION_NOT_READY:
1604         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1605         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1606         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1607                 break;
1608         case TCM_OUT_OF_RESOURCES:
1609                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1610                 break;
1611         case TCM_RESERVATION_CONFLICT:
1612                 /*
1613                  * No SENSE Data payload for this case, set SCSI Status
1614                  * and queue the response to $FABRIC_MOD.
1615                  *
1616                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1617                  */
1618                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1619                 /*
1620                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1621                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1622                  * CONFLICT STATUS.
1623                  *
1624                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1625                  */
1626                 if (cmd->se_sess &&
1627                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1628                         core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1629                                 cmd->orig_fe_lun, 0x2C,
1630                                 ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1631
1632                 trace_target_cmd_complete(cmd);
1633                 ret = cmd->se_tfo-> queue_status(cmd);
1634                 if (ret == -EAGAIN || ret == -ENOMEM)
1635                         goto queue_full;
1636                 goto check_stop;
1637         default:
1638                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1639                         cmd->t_task_cdb[0], sense_reason);
1640                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1641                 break;
1642         }
1643
1644         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1645         if (ret == -EAGAIN || ret == -ENOMEM)
1646                 goto queue_full;
1647
1648 check_stop:
1649         transport_lun_remove_cmd(cmd);
1650         if (!transport_cmd_check_stop_to_fabric(cmd))
1651                 ;
1652         return;
1653
1654 queue_full:
1655         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1656         transport_handle_queue_full(cmd, cmd->se_dev);
1657 }
1658 EXPORT_SYMBOL(transport_generic_request_failure);
1659
1660 void __target_execute_cmd(struct se_cmd *cmd)
1661 {
1662         sense_reason_t ret;
1663
1664         if (cmd->execute_cmd) {
1665                 ret = cmd->execute_cmd(cmd);
1666                 if (ret) {
1667                         spin_lock_irq(&cmd->t_state_lock);
1668                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1669                         spin_unlock_irq(&cmd->t_state_lock);
1670
1671                         transport_generic_request_failure(cmd, ret);
1672                 }
1673         }
1674 }
1675
1676 static bool target_handle_task_attr(struct se_cmd *cmd)
1677 {
1678         struct se_device *dev = cmd->se_dev;
1679
1680         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1681                 return false;
1682
1683         /*
1684          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1685          * to allow the passed struct se_cmd list of tasks to the front of the list.
1686          */
1687         switch (cmd->sam_task_attr) {
1688         case MSG_HEAD_TAG:
1689                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1690                          "se_ordered_id: %u\n",
1691                          cmd->t_task_cdb[0], cmd->se_ordered_id);
1692                 return false;
1693         case MSG_ORDERED_TAG:
1694                 atomic_inc(&dev->dev_ordered_sync);
1695                 smp_mb__after_atomic_inc();
1696
1697                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1698                          " se_ordered_id: %u\n",
1699                          cmd->t_task_cdb[0], cmd->se_ordered_id);
1700
1701                 /*
1702                  * Execute an ORDERED command if no other older commands
1703                  * exist that need to be completed first.
1704                  */
1705                 if (!atomic_read(&dev->simple_cmds))
1706                         return false;
1707                 break;
1708         default:
1709                 /*
1710                  * For SIMPLE and UNTAGGED Task Attribute commands
1711                  */
1712                 atomic_inc(&dev->simple_cmds);
1713                 smp_mb__after_atomic_inc();
1714                 break;
1715         }
1716
1717         if (atomic_read(&dev->dev_ordered_sync) == 0)
1718                 return false;
1719
1720         spin_lock(&dev->delayed_cmd_lock);
1721         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1722         spin_unlock(&dev->delayed_cmd_lock);
1723
1724         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1725                 " delayed CMD list, se_ordered_id: %u\n",
1726                 cmd->t_task_cdb[0], cmd->sam_task_attr,
1727                 cmd->se_ordered_id);
1728         return true;
1729 }
1730
1731 void target_execute_cmd(struct se_cmd *cmd)
1732 {
1733         /*
1734          * If the received CDB has aleady been aborted stop processing it here.
1735          */
1736         if (transport_check_aborted_status(cmd, 1))
1737                 return;
1738
1739         /*
1740          * Determine if frontend context caller is requesting the stopping of
1741          * this command for frontend exceptions.
1742          */
1743         spin_lock_irq(&cmd->t_state_lock);
1744         if (cmd->transport_state & CMD_T_STOP) {
1745                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1746                         __func__, __LINE__,
1747                         cmd->se_tfo->get_task_tag(cmd));
1748
1749                 spin_unlock_irq(&cmd->t_state_lock);
1750                 complete(&cmd->t_transport_stop_comp);
1751                 return;
1752         }
1753
1754         cmd->t_state = TRANSPORT_PROCESSING;
1755         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1756         spin_unlock_irq(&cmd->t_state_lock);
1757
1758         if (target_handle_task_attr(cmd)) {
1759                 spin_lock_irq(&cmd->t_state_lock);
1760                 cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT;
1761                 spin_unlock_irq(&cmd->t_state_lock);
1762                 return;
1763         }
1764
1765         __target_execute_cmd(cmd);
1766 }
1767 EXPORT_SYMBOL(target_execute_cmd);
1768
1769 /*
1770  * Process all commands up to the last received ORDERED task attribute which
1771  * requires another blocking boundary
1772  */
1773 static void target_restart_delayed_cmds(struct se_device *dev)
1774 {
1775         for (;;) {
1776                 struct se_cmd *cmd;
1777
1778                 spin_lock(&dev->delayed_cmd_lock);
1779                 if (list_empty(&dev->delayed_cmd_list)) {
1780                         spin_unlock(&dev->delayed_cmd_lock);
1781                         break;
1782                 }
1783
1784                 cmd = list_entry(dev->delayed_cmd_list.next,
1785                                  struct se_cmd, se_delayed_node);
1786                 list_del(&cmd->se_delayed_node);
1787                 spin_unlock(&dev->delayed_cmd_lock);
1788
1789                 __target_execute_cmd(cmd);
1790
1791                 if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1792                         break;
1793         }
1794 }
1795
1796 /*
1797  * Called from I/O completion to determine which dormant/delayed
1798  * and ordered cmds need to have their tasks added to the execution queue.
1799  */
1800 static void transport_complete_task_attr(struct se_cmd *cmd)
1801 {
1802         struct se_device *dev = cmd->se_dev;
1803
1804         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1805                 return;
1806
1807         if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1808                 atomic_dec(&dev->simple_cmds);
1809                 smp_mb__after_atomic_dec();
1810                 dev->dev_cur_ordered_id++;
1811                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1812                         " SIMPLE: %u\n", dev->dev_cur_ordered_id,
1813                         cmd->se_ordered_id);
1814         } else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1815                 dev->dev_cur_ordered_id++;
1816                 pr_debug("Incremented dev_cur_ordered_id: %u for"
1817                         " HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1818                         cmd->se_ordered_id);
1819         } else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1820                 atomic_dec(&dev->dev_ordered_sync);
1821                 smp_mb__after_atomic_dec();
1822
1823                 dev->dev_cur_ordered_id++;
1824                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1825                         " %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1826         }
1827
1828         target_restart_delayed_cmds(dev);
1829 }
1830
1831 static void transport_complete_qf(struct se_cmd *cmd)
1832 {
1833         int ret = 0;
1834
1835         transport_complete_task_attr(cmd);
1836
1837         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1838                 trace_target_cmd_complete(cmd);
1839                 ret = cmd->se_tfo->queue_status(cmd);
1840                 if (ret)
1841                         goto out;
1842         }
1843
1844         switch (cmd->data_direction) {
1845         case DMA_FROM_DEVICE:
1846                 trace_target_cmd_complete(cmd);
1847                 ret = cmd->se_tfo->queue_data_in(cmd);
1848                 break;
1849         case DMA_TO_DEVICE:
1850                 if (cmd->se_cmd_flags & SCF_BIDI) {
1851                         ret = cmd->se_tfo->queue_data_in(cmd);
1852                         if (ret < 0)
1853                                 break;
1854                 }
1855                 /* Fall through for DMA_TO_DEVICE */
1856         case DMA_NONE:
1857                 trace_target_cmd_complete(cmd);
1858                 ret = cmd->se_tfo->queue_status(cmd);
1859                 break;
1860         default:
1861                 break;
1862         }
1863
1864 out:
1865         if (ret < 0) {
1866                 transport_handle_queue_full(cmd, cmd->se_dev);
1867                 return;
1868         }
1869         transport_lun_remove_cmd(cmd);
1870         transport_cmd_check_stop_to_fabric(cmd);
1871 }
1872
1873 static void transport_handle_queue_full(
1874         struct se_cmd *cmd,
1875         struct se_device *dev)
1876 {
1877         spin_lock_irq(&dev->qf_cmd_lock);
1878         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1879         atomic_inc(&dev->dev_qf_count);
1880         smp_mb__after_atomic_inc();
1881         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1882
1883         schedule_work(&cmd->se_dev->qf_work_queue);
1884 }
1885
1886 static void target_complete_ok_work(struct work_struct *work)
1887 {
1888         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1889         int ret;
1890
1891         /*
1892          * Check if we need to move delayed/dormant tasks from cmds on the
1893          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1894          * Attribute.
1895          */
1896         transport_complete_task_attr(cmd);
1897
1898         /*
1899          * Check to schedule QUEUE_FULL work, or execute an existing
1900          * cmd->transport_qf_callback()
1901          */
1902         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1903                 schedule_work(&cmd->se_dev->qf_work_queue);
1904
1905         /*
1906          * Check if we need to send a sense buffer from
1907          * the struct se_cmd in question.
1908          */
1909         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1910                 WARN_ON(!cmd->scsi_status);
1911                 ret = transport_send_check_condition_and_sense(
1912                                         cmd, 0, 1);
1913                 if (ret == -EAGAIN || ret == -ENOMEM)
1914                         goto queue_full;
1915
1916                 transport_lun_remove_cmd(cmd);
1917                 transport_cmd_check_stop_to_fabric(cmd);
1918                 return;
1919         }
1920         /*
1921          * Check for a callback, used by amongst other things
1922          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
1923          */
1924         if (cmd->transport_complete_callback) {
1925                 sense_reason_t rc;
1926
1927                 rc = cmd->transport_complete_callback(cmd);
1928                 if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
1929                         return;
1930                 } else if (rc) {
1931                         ret = transport_send_check_condition_and_sense(cmd,
1932                                                 rc, 0);
1933                         if (ret == -EAGAIN || ret == -ENOMEM)
1934                                 goto queue_full;
1935
1936                         transport_lun_remove_cmd(cmd);
1937                         transport_cmd_check_stop_to_fabric(cmd);
1938                         return;
1939                 }
1940         }
1941
1942         switch (cmd->data_direction) {
1943         case DMA_FROM_DEVICE:
1944                 spin_lock(&cmd->se_lun->lun_sep_lock);
1945                 if (cmd->se_lun->lun_sep) {
1946                         cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1947                                         cmd->data_length;
1948                 }
1949                 spin_unlock(&cmd->se_lun->lun_sep_lock);
1950
1951                 trace_target_cmd_complete(cmd);
1952                 ret = cmd->se_tfo->queue_data_in(cmd);
1953                 if (ret == -EAGAIN || ret == -ENOMEM)
1954                         goto queue_full;
1955                 break;
1956         case DMA_TO_DEVICE:
1957                 spin_lock(&cmd->se_lun->lun_sep_lock);
1958                 if (cmd->se_lun->lun_sep) {
1959                         cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
1960                                 cmd->data_length;
1961                 }
1962                 spin_unlock(&cmd->se_lun->lun_sep_lock);
1963                 /*
1964                  * Check if we need to send READ payload for BIDI-COMMAND
1965                  */
1966                 if (cmd->se_cmd_flags & SCF_BIDI) {
1967                         spin_lock(&cmd->se_lun->lun_sep_lock);
1968                         if (cmd->se_lun->lun_sep) {
1969                                 cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1970                                         cmd->data_length;
1971                         }
1972                         spin_unlock(&cmd->se_lun->lun_sep_lock);
1973                         ret = cmd->se_tfo->queue_data_in(cmd);
1974                         if (ret == -EAGAIN || ret == -ENOMEM)
1975                                 goto queue_full;
1976                         break;
1977                 }
1978                 /* Fall through for DMA_TO_DEVICE */
1979         case DMA_NONE:
1980                 trace_target_cmd_complete(cmd);
1981                 ret = cmd->se_tfo->queue_status(cmd);
1982                 if (ret == -EAGAIN || ret == -ENOMEM)
1983                         goto queue_full;
1984                 break;
1985         default:
1986                 break;
1987         }
1988
1989         transport_lun_remove_cmd(cmd);
1990         transport_cmd_check_stop_to_fabric(cmd);
1991         return;
1992
1993 queue_full:
1994         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
1995                 " data_direction: %d\n", cmd, cmd->data_direction);
1996         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1997         transport_handle_queue_full(cmd, cmd->se_dev);
1998 }
1999
2000 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2001 {
2002         struct scatterlist *sg;
2003         int count;
2004
2005         for_each_sg(sgl, sg, nents, count)
2006                 __free_page(sg_page(sg));
2007
2008         kfree(sgl);
2009 }
2010
2011 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2012 {
2013         /*
2014          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2015          * emulation, and free + reset pointers if necessary..
2016          */
2017         if (!cmd->t_data_sg_orig)
2018                 return;
2019
2020         kfree(cmd->t_data_sg);
2021         cmd->t_data_sg = cmd->t_data_sg_orig;
2022         cmd->t_data_sg_orig = NULL;
2023         cmd->t_data_nents = cmd->t_data_nents_orig;
2024         cmd->t_data_nents_orig = 0;
2025 }
2026
2027 static inline void transport_free_pages(struct se_cmd *cmd)
2028 {
2029         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2030                 transport_reset_sgl_orig(cmd);
2031                 return;
2032         }
2033         transport_reset_sgl_orig(cmd);
2034
2035         transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2036         cmd->t_data_sg = NULL;
2037         cmd->t_data_nents = 0;
2038
2039         transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2040         cmd->t_bidi_data_sg = NULL;
2041         cmd->t_bidi_data_nents = 0;
2042
2043         transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2044         cmd->t_prot_sg = NULL;
2045         cmd->t_prot_nents = 0;
2046 }
2047
2048 /**
2049  * transport_release_cmd - free a command
2050  * @cmd:       command to free
2051  *
2052  * This routine unconditionally frees a command, and reference counting
2053  * or list removal must be done in the caller.
2054  */
2055 static int transport_release_cmd(struct se_cmd *cmd)
2056 {
2057         BUG_ON(!cmd->se_tfo);
2058
2059         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2060                 core_tmr_release_req(cmd->se_tmr_req);
2061         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2062                 kfree(cmd->t_task_cdb);
2063         /*
2064          * If this cmd has been setup with target_get_sess_cmd(), drop
2065          * the kref and call ->release_cmd() in kref callback.
2066          */
2067         return target_put_sess_cmd(cmd->se_sess, cmd);
2068 }
2069
2070 /**
2071  * transport_put_cmd - release a reference to a command
2072  * @cmd:       command to release
2073  *
2074  * This routine releases our reference to the command and frees it if possible.
2075  */
2076 static int transport_put_cmd(struct se_cmd *cmd)
2077 {
2078         transport_free_pages(cmd);
2079         return transport_release_cmd(cmd);
2080 }
2081
2082 void *transport_kmap_data_sg(struct se_cmd *cmd)
2083 {
2084         struct scatterlist *sg = cmd->t_data_sg;
2085         struct page **pages;
2086         int i;
2087
2088         /*
2089          * We need to take into account a possible offset here for fabrics like
2090          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2091          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2092          */
2093         if (!cmd->t_data_nents)
2094                 return NULL;
2095
2096         BUG_ON(!sg);
2097         if (cmd->t_data_nents == 1)
2098                 return kmap(sg_page(sg)) + sg->offset;
2099
2100         /* >1 page. use vmap */
2101         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2102         if (!pages)
2103                 return NULL;
2104
2105         /* convert sg[] to pages[] */
2106         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2107                 pages[i] = sg_page(sg);
2108         }
2109
2110         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2111         kfree(pages);
2112         if (!cmd->t_data_vmap)
2113                 return NULL;
2114
2115         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2116 }
2117 EXPORT_SYMBOL(transport_kmap_data_sg);
2118
2119 void transport_kunmap_data_sg(struct se_cmd *cmd)
2120 {
2121         if (!cmd->t_data_nents) {
2122                 return;
2123         } else if (cmd->t_data_nents == 1) {
2124                 kunmap(sg_page(cmd->t_data_sg));
2125                 return;
2126         }
2127
2128         vunmap(cmd->t_data_vmap);
2129         cmd->t_data_vmap = NULL;
2130 }
2131 EXPORT_SYMBOL(transport_kunmap_data_sg);
2132
2133 int
2134 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2135                  bool zero_page)
2136 {
2137         struct scatterlist *sg;
2138         struct page *page;
2139         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2140         unsigned int nent;
2141         int i = 0;
2142
2143         nent = DIV_ROUND_UP(length, PAGE_SIZE);
2144         sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2145         if (!sg)
2146                 return -ENOMEM;
2147
2148         sg_init_table(sg, nent);
2149
2150         while (length) {
2151                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2152                 page = alloc_page(GFP_KERNEL | zero_flag);
2153                 if (!page)
2154                         goto out;
2155
2156                 sg_set_page(&sg[i], page, page_len, 0);
2157                 length -= page_len;
2158                 i++;
2159         }
2160         *sgl = sg;
2161         *nents = nent;
2162         return 0;
2163
2164 out:
2165         while (i > 0) {
2166                 i--;
2167                 __free_page(sg_page(&sg[i]));
2168         }
2169         kfree(sg);
2170         return -ENOMEM;
2171 }
2172
2173 /*
2174  * Allocate any required resources to execute the command.  For writes we
2175  * might not have the payload yet, so notify the fabric via a call to
2176  * ->write_pending instead. Otherwise place it on the execution queue.
2177  */
2178 sense_reason_t
2179 transport_generic_new_cmd(struct se_cmd *cmd)
2180 {
2181         int ret = 0;
2182
2183         /*
2184          * Determine is the TCM fabric module has already allocated physical
2185          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2186          * beforehand.
2187          */
2188         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2189             cmd->data_length) {
2190                 bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2191
2192                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2193                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2194                         u32 bidi_length;
2195
2196                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2197                                 bidi_length = cmd->t_task_nolb *
2198                                               cmd->se_dev->dev_attrib.block_size;
2199                         else
2200                                 bidi_length = cmd->data_length;
2201
2202                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2203                                                &cmd->t_bidi_data_nents,
2204                                                bidi_length, zero_flag);
2205                         if (ret < 0)
2206                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2207                 }
2208
2209                 if (cmd->prot_op != TARGET_PROT_NORMAL) {
2210                         ret = target_alloc_sgl(&cmd->t_prot_sg,
2211                                                &cmd->t_prot_nents,
2212                                                cmd->prot_length, true);
2213                         if (ret < 0)
2214                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2215                 }
2216
2217                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2218                                        cmd->data_length, zero_flag);
2219                 if (ret < 0)
2220                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2221         }
2222         /*
2223          * If this command is not a write we can execute it right here,
2224          * for write buffers we need to notify the fabric driver first
2225          * and let it call back once the write buffers are ready.
2226          */
2227         target_add_to_state_list(cmd);
2228         if (cmd->data_direction != DMA_TO_DEVICE) {
2229                 target_execute_cmd(cmd);
2230                 return 0;
2231         }
2232         transport_cmd_check_stop(cmd, false, true);
2233
2234         ret = cmd->se_tfo->write_pending(cmd);
2235         if (ret == -EAGAIN || ret == -ENOMEM)
2236                 goto queue_full;
2237
2238         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2239         WARN_ON(ret);
2240
2241         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2242
2243 queue_full:
2244         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2245         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2246         transport_handle_queue_full(cmd, cmd->se_dev);
2247         return 0;
2248 }
2249 EXPORT_SYMBOL(transport_generic_new_cmd);
2250
2251 static void transport_write_pending_qf(struct se_cmd *cmd)
2252 {
2253         int ret;
2254
2255         ret = cmd->se_tfo->write_pending(cmd);
2256         if (ret == -EAGAIN || ret == -ENOMEM) {
2257                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2258                          cmd);
2259                 transport_handle_queue_full(cmd, cmd->se_dev);
2260         }
2261 }
2262
2263 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2264 {
2265         unsigned long flags;
2266         int ret = 0;
2267
2268         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2269                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2270                          transport_wait_for_tasks(cmd);
2271
2272                 ret = transport_release_cmd(cmd);
2273         } else {
2274                 if (wait_for_tasks)
2275                         transport_wait_for_tasks(cmd);
2276                 /*
2277                  * Handle WRITE failure case where transport_generic_new_cmd()
2278                  * has already added se_cmd to state_list, but fabric has
2279                  * failed command before I/O submission.
2280                  */
2281                 if (cmd->state_active) {
2282                         spin_lock_irqsave(&cmd->t_state_lock, flags);
2283                         target_remove_from_state_list(cmd);
2284                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2285                 }
2286
2287                 if (cmd->se_lun)
2288                         transport_lun_remove_cmd(cmd);
2289
2290                 ret = transport_put_cmd(cmd);
2291         }
2292         return ret;
2293 }
2294 EXPORT_SYMBOL(transport_generic_free_cmd);
2295
2296 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2297  * @se_sess:    session to reference
2298  * @se_cmd:     command descriptor to add
2299  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2300  */
2301 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2302                                bool ack_kref)
2303 {
2304         unsigned long flags;
2305         int ret = 0;
2306
2307         kref_init(&se_cmd->cmd_kref);
2308         /*
2309          * Add a second kref if the fabric caller is expecting to handle
2310          * fabric acknowledgement that requires two target_put_sess_cmd()
2311          * invocations before se_cmd descriptor release.
2312          */
2313         if (ack_kref == true) {
2314                 kref_get(&se_cmd->cmd_kref);
2315                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2316         }
2317
2318         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2319         if (se_sess->sess_tearing_down) {
2320                 ret = -ESHUTDOWN;
2321                 goto out;
2322         }
2323         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2324 out:
2325         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2326         return ret;
2327 }
2328 EXPORT_SYMBOL(target_get_sess_cmd);
2329
2330 static void target_release_cmd_kref(struct kref *kref)
2331 {
2332         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2333         struct se_session *se_sess = se_cmd->se_sess;
2334
2335         if (list_empty(&se_cmd->se_cmd_list)) {
2336                 spin_unlock(&se_sess->sess_cmd_lock);
2337                 se_cmd->se_tfo->release_cmd(se_cmd);
2338                 return;
2339         }
2340         if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2341                 spin_unlock(&se_sess->sess_cmd_lock);
2342                 complete(&se_cmd->cmd_wait_comp);
2343                 return;
2344         }
2345         list_del(&se_cmd->se_cmd_list);
2346         spin_unlock(&se_sess->sess_cmd_lock);
2347
2348         se_cmd->se_tfo->release_cmd(se_cmd);
2349 }
2350
2351 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2352  * @se_sess:    session to reference
2353  * @se_cmd:     command descriptor to drop
2354  */
2355 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2356 {
2357         return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2358                         &se_sess->sess_cmd_lock);
2359 }
2360 EXPORT_SYMBOL(target_put_sess_cmd);
2361
2362 /* target_sess_cmd_list_set_waiting - Flag all commands in
2363  *         sess_cmd_list to complete cmd_wait_comp.  Set
2364  *         sess_tearing_down so no more commands are queued.
2365  * @se_sess:    session to flag
2366  */
2367 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2368 {
2369         struct se_cmd *se_cmd;
2370         unsigned long flags;
2371
2372         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2373         if (se_sess->sess_tearing_down) {
2374                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2375                 return;
2376         }
2377         se_sess->sess_tearing_down = 1;
2378         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2379
2380         list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2381                 se_cmd->cmd_wait_set = 1;
2382
2383         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2384 }
2385 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2386
2387 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2388  * @se_sess:    session to wait for active I/O
2389  */
2390 void target_wait_for_sess_cmds(struct se_session *se_sess)
2391 {
2392         struct se_cmd *se_cmd, *tmp_cmd;
2393         unsigned long flags;
2394
2395         list_for_each_entry_safe(se_cmd, tmp_cmd,
2396                                 &se_sess->sess_wait_list, se_cmd_list) {
2397                 list_del(&se_cmd->se_cmd_list);
2398
2399                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2400                         " %d\n", se_cmd, se_cmd->t_state,
2401                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2402
2403                 wait_for_completion(&se_cmd->cmd_wait_comp);
2404                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2405                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2406                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2407
2408                 se_cmd->se_tfo->release_cmd(se_cmd);
2409         }
2410
2411         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2412         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2413         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2414
2415 }
2416 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2417
2418 static int transport_clear_lun_ref_thread(void *p)
2419 {
2420         struct se_lun *lun = p;
2421
2422         percpu_ref_kill(&lun->lun_ref);
2423
2424         wait_for_completion(&lun->lun_ref_comp);
2425         complete(&lun->lun_shutdown_comp);
2426
2427         return 0;
2428 }
2429
2430 int transport_clear_lun_ref(struct se_lun *lun)
2431 {
2432         struct task_struct *kt;
2433
2434         kt = kthread_run(transport_clear_lun_ref_thread, lun,
2435                         "tcm_cl_%u", lun->unpacked_lun);
2436         if (IS_ERR(kt)) {
2437                 pr_err("Unable to start clear_lun thread\n");
2438                 return PTR_ERR(kt);
2439         }
2440         wait_for_completion(&lun->lun_shutdown_comp);
2441
2442         return 0;
2443 }
2444
2445 /**
2446  * transport_wait_for_tasks - wait for completion to occur
2447  * @cmd:        command to wait
2448  *
2449  * Called from frontend fabric context to wait for storage engine
2450  * to pause and/or release frontend generated struct se_cmd.
2451  */
2452 bool transport_wait_for_tasks(struct se_cmd *cmd)
2453 {
2454         unsigned long flags;
2455
2456         spin_lock_irqsave(&cmd->t_state_lock, flags);
2457         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2458             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2459                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2460                 return false;
2461         }
2462
2463         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2464             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2465                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2466                 return false;
2467         }
2468
2469         if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2470                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2471                 return false;
2472         }
2473
2474         cmd->transport_state |= CMD_T_STOP;
2475
2476         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2477                 " i_state: %d, t_state: %d, CMD_T_STOP\n",
2478                 cmd, cmd->se_tfo->get_task_tag(cmd),
2479                 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2480
2481         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2482
2483         wait_for_completion(&cmd->t_transport_stop_comp);
2484
2485         spin_lock_irqsave(&cmd->t_state_lock, flags);
2486         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2487
2488         pr_debug("wait_for_tasks: Stopped wait_for_completion("
2489                 "&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2490                 cmd->se_tfo->get_task_tag(cmd));
2491
2492         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2493
2494         return true;
2495 }
2496 EXPORT_SYMBOL(transport_wait_for_tasks);
2497
2498 static int transport_get_sense_codes(
2499         struct se_cmd *cmd,
2500         u8 *asc,
2501         u8 *ascq)
2502 {
2503         *asc = cmd->scsi_asc;
2504         *ascq = cmd->scsi_ascq;
2505
2506         return 0;
2507 }
2508
2509 static
2510 void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
2511 {
2512         /* Place failed LBA in sense data information descriptor 0. */
2513         buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
2514         buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
2515         buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
2516         buffer[SPC_VALIDITY_OFFSET] = 0x80;
2517
2518         /* Descriptor Information: failing sector */
2519         put_unaligned_be64(bad_sector, &buffer[12]);
2520 }
2521
2522 int
2523 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2524                 sense_reason_t reason, int from_transport)
2525 {
2526         unsigned char *buffer = cmd->sense_buffer;
2527         unsigned long flags;
2528         u8 asc = 0, ascq = 0;
2529
2530         spin_lock_irqsave(&cmd->t_state_lock, flags);
2531         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2532                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2533                 return 0;
2534         }
2535         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2536         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2537
2538         if (!reason && from_transport)
2539                 goto after_reason;
2540
2541         if (!from_transport)
2542                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2543
2544         /*
2545          * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2546          * SENSE KEY values from include/scsi/scsi.h
2547          */
2548         switch (reason) {
2549         case TCM_NO_SENSE:
2550                 /* CURRENT ERROR */
2551                 buffer[0] = 0x70;
2552                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2553                 /* Not Ready */
2554                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2555                 /* NO ADDITIONAL SENSE INFORMATION */
2556                 buffer[SPC_ASC_KEY_OFFSET] = 0;
2557                 buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2558                 break;
2559         case TCM_NON_EXISTENT_LUN:
2560                 /* CURRENT ERROR */
2561                 buffer[0] = 0x70;
2562                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2563                 /* ILLEGAL REQUEST */
2564                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2565                 /* LOGICAL UNIT NOT SUPPORTED */
2566                 buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2567                 break;
2568         case TCM_UNSUPPORTED_SCSI_OPCODE:
2569         case TCM_SECTOR_COUNT_TOO_MANY:
2570                 /* CURRENT ERROR */
2571                 buffer[0] = 0x70;
2572                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2573                 /* ILLEGAL REQUEST */
2574                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2575                 /* INVALID COMMAND OPERATION CODE */
2576                 buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2577                 break;
2578         case TCM_UNKNOWN_MODE_PAGE:
2579                 /* CURRENT ERROR */
2580                 buffer[0] = 0x70;
2581                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2582                 /* ILLEGAL REQUEST */
2583                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2584                 /* INVALID FIELD IN CDB */
2585                 buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2586                 break;
2587         case TCM_CHECK_CONDITION_ABORT_CMD:
2588                 /* CURRENT ERROR */
2589                 buffer[0] = 0x70;
2590                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2591                 /* ABORTED COMMAND */
2592                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2593                 /* BUS DEVICE RESET FUNCTION OCCURRED */
2594                 buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2595                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2596                 break;
2597         case TCM_INCORRECT_AMOUNT_OF_DATA:
2598                 /* CURRENT ERROR */
2599                 buffer[0] = 0x70;
2600                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2601                 /* ABORTED COMMAND */
2602                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2603                 /* WRITE ERROR */
2604                 buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2605                 /* NOT ENOUGH UNSOLICITED DATA */
2606                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2607                 break;
2608         case TCM_INVALID_CDB_FIELD:
2609                 /* CURRENT ERROR */
2610                 buffer[0] = 0x70;
2611                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2612                 /* ILLEGAL REQUEST */
2613                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2614                 /* INVALID FIELD IN CDB */
2615                 buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2616                 break;
2617         case TCM_INVALID_PARAMETER_LIST:
2618                 /* CURRENT ERROR */
2619                 buffer[0] = 0x70;
2620                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2621                 /* ILLEGAL REQUEST */
2622                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2623                 /* INVALID FIELD IN PARAMETER LIST */
2624                 buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2625                 break;
2626         case TCM_PARAMETER_LIST_LENGTH_ERROR:
2627                 /* CURRENT ERROR */
2628                 buffer[0] = 0x70;
2629                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2630                 /* ILLEGAL REQUEST */
2631                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2632                 /* PARAMETER LIST LENGTH ERROR */
2633                 buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2634                 break;
2635         case TCM_UNEXPECTED_UNSOLICITED_DATA:
2636                 /* CURRENT ERROR */
2637                 buffer[0] = 0x70;
2638                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2639                 /* ABORTED COMMAND */
2640                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2641                 /* WRITE ERROR */
2642                 buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2643                 /* UNEXPECTED_UNSOLICITED_DATA */
2644                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2645                 break;
2646         case TCM_SERVICE_CRC_ERROR:
2647                 /* CURRENT ERROR */
2648                 buffer[0] = 0x70;
2649                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2650                 /* ABORTED COMMAND */
2651                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2652                 /* PROTOCOL SERVICE CRC ERROR */
2653                 buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2654                 /* N/A */
2655                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2656                 break;
2657         case TCM_SNACK_REJECTED:
2658                 /* CURRENT ERROR */
2659                 buffer[0] = 0x70;
2660                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2661                 /* ABORTED COMMAND */
2662                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2663                 /* READ ERROR */
2664                 buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2665                 /* FAILED RETRANSMISSION REQUEST */
2666                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2667                 break;
2668         case TCM_WRITE_PROTECTED:
2669                 /* CURRENT ERROR */
2670                 buffer[0] = 0x70;
2671                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2672                 /* DATA PROTECT */
2673                 buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2674                 /* WRITE PROTECTED */
2675                 buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2676                 break;
2677         case TCM_ADDRESS_OUT_OF_RANGE:
2678                 /* CURRENT ERROR */
2679                 buffer[0] = 0x70;
2680                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2681                 /* ILLEGAL REQUEST */
2682                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2683                 /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2684                 buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2685                 break;
2686         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2687                 /* CURRENT ERROR */
2688                 buffer[0] = 0x70;
2689                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2690                 /* UNIT ATTENTION */
2691                 buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2692                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2693                 buffer[SPC_ASC_KEY_OFFSET] = asc;
2694                 buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2695                 break;
2696         case TCM_CHECK_CONDITION_NOT_READY:
2697                 /* CURRENT ERROR */
2698                 buffer[0] = 0x70;
2699                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2700                 /* Not Ready */
2701                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2702                 transport_get_sense_codes(cmd, &asc, &ascq);
2703                 buffer[SPC_ASC_KEY_OFFSET] = asc;
2704                 buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2705                 break;
2706         case TCM_MISCOMPARE_VERIFY:
2707                 /* CURRENT ERROR */
2708                 buffer[0] = 0x70;
2709                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2710                 buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2711                 /* MISCOMPARE DURING VERIFY OPERATION */
2712                 buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2713                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2714                 break;
2715         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2716                 /* CURRENT ERROR */
2717                 buffer[0] = 0x70;
2718                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2719                 /* ILLEGAL REQUEST */
2720                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2721                 /* LOGICAL BLOCK GUARD CHECK FAILED */
2722                 buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2723                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
2724                 transport_err_sector_info(buffer, cmd->bad_sector);
2725                 break;
2726         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2727                 /* CURRENT ERROR */
2728                 buffer[0] = 0x70;
2729                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2730                 /* ILLEGAL REQUEST */
2731                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2732                 /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2733                 buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2734                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
2735                 transport_err_sector_info(buffer, cmd->bad_sector);
2736                 break;
2737         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2738                 /* CURRENT ERROR */
2739                 buffer[0] = 0x70;
2740                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2741                 /* ILLEGAL REQUEST */
2742                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2743                 /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2744                 buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2745                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2746                 transport_err_sector_info(buffer, cmd->bad_sector);
2747                 break;
2748         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2749         default:
2750                 /* CURRENT ERROR */
2751                 buffer[0] = 0x70;
2752                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2753                 /*
2754                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2755                  * Solaris initiators.  Returning NOT READY instead means the
2756                  * operations will be retried a finite number of times and we
2757                  * can survive intermittent errors.
2758                  */
2759                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2760                 /* LOGICAL UNIT COMMUNICATION FAILURE */
2761                 buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2762                 break;
2763         }
2764         /*
2765          * This code uses linux/include/scsi/scsi.h SAM status codes!
2766          */
2767         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2768         /*
2769          * Automatically padded, this value is encoded in the fabric's
2770          * data_length response PDU containing the SCSI defined sense data.
2771          */
2772         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2773
2774 after_reason:
2775         trace_target_cmd_complete(cmd);
2776         return cmd->se_tfo->queue_status(cmd);
2777 }
2778 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2779
2780 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2781 {
2782         if (!(cmd->transport_state & CMD_T_ABORTED))
2783                 return 0;
2784
2785         if (!send_status || (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
2786                 return 1;
2787
2788         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2789                  cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2790
2791         cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
2792         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2793         trace_target_cmd_complete(cmd);
2794         cmd->se_tfo->queue_status(cmd);
2795
2796         return 1;
2797 }
2798 EXPORT_SYMBOL(transport_check_aborted_status);
2799
2800 void transport_send_task_abort(struct se_cmd *cmd)
2801 {
2802         unsigned long flags;
2803
2804         spin_lock_irqsave(&cmd->t_state_lock, flags);
2805         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION | SCF_SENT_DELAYED_TAS)) {
2806                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2807                 return;
2808         }
2809         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2810
2811         /*
2812          * If there are still expected incoming fabric WRITEs, we wait
2813          * until until they have completed before sending a TASK_ABORTED
2814          * response.  This response with TASK_ABORTED status will be
2815          * queued back to fabric module by transport_check_aborted_status().
2816          */
2817         if (cmd->data_direction == DMA_TO_DEVICE) {
2818                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2819                         cmd->transport_state |= CMD_T_ABORTED;
2820                         smp_mb__after_atomic_inc();
2821                         return;
2822                 }
2823         }
2824         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2825
2826         transport_lun_remove_cmd(cmd);
2827
2828         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2829                 " ITT: 0x%08x\n", cmd->t_task_cdb[0],
2830                 cmd->se_tfo->get_task_tag(cmd));
2831
2832         trace_target_cmd_complete(cmd);
2833         cmd->se_tfo->queue_status(cmd);
2834 }
2835
2836 static void target_tmr_work(struct work_struct *work)
2837 {
2838         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2839         struct se_device *dev = cmd->se_dev;
2840         struct se_tmr_req *tmr = cmd->se_tmr_req;
2841         int ret;
2842
2843         switch (tmr->function) {
2844         case TMR_ABORT_TASK:
2845                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
2846                 break;
2847         case TMR_ABORT_TASK_SET:
2848         case TMR_CLEAR_ACA:
2849         case TMR_CLEAR_TASK_SET:
2850                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2851                 break;
2852         case TMR_LUN_RESET:
2853                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2854                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2855                                          TMR_FUNCTION_REJECTED;
2856                 break;
2857         case TMR_TARGET_WARM_RESET:
2858                 tmr->response = TMR_FUNCTION_REJECTED;
2859                 break;
2860         case TMR_TARGET_COLD_RESET:
2861                 tmr->response = TMR_FUNCTION_REJECTED;
2862                 break;
2863         default:
2864                 pr_err("Uknown TMR function: 0x%02x.\n",
2865                                 tmr->function);
2866                 tmr->response = TMR_FUNCTION_REJECTED;
2867                 break;
2868         }
2869
2870         cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2871         cmd->se_tfo->queue_tm_rsp(cmd);
2872
2873         transport_cmd_check_stop_to_fabric(cmd);
2874 }
2875
2876 int transport_generic_handle_tmr(
2877         struct se_cmd *cmd)
2878 {
2879         INIT_WORK(&cmd->work, target_tmr_work);
2880         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2881         return 0;
2882 }
2883 EXPORT_SYMBOL(transport_generic_handle_tmr);