drivers/target/target_core_transport.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * Filename:  target_core_transport.c
   4  *
   5  * This file contains the Generic Target Engine Core.
   6  *
   7  * (c) Copyright 2002-2013 Datera, Inc.
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  ******************************************************************************/
  12
  13 #include <linux/net.h>
  14 #include <linux/delay.h>
  15 #include <linux/string.h>
  16 #include <linux/timer.h>
  17 #include <linux/slab.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/kthread.h>
  20 #include <linux/in.h>
  21 #include <linux/cdrom.h>
  22 #include <linux/module.h>
  23 #include <linux/ratelimit.h>
  24 #include <linux/vmalloc.h>
  25 #include <asm/unaligned.h>
  26 #include <net/sock.h>
  27 #include <net/tcp.h>
  28 #include <scsi/scsi_proto.h>
  29 #include <scsi/scsi_common.h>
  30
  31 #include <target/target_core_base.h>
  32 #include <target/target_core_backend.h>
  33 #include <target/target_core_fabric.h>
  34
  35 #include "target_core_internal.h"
  36 #include "target_core_alua.h"
  37 #include "target_core_pr.h"
  38 #include "target_core_ua.h"
  39
  40 #define CREATE_TRACE_POINTS
  41 #include <trace/events/target.h>
  42
  43 static struct workqueue_struct *target_completion_wq;
  44 static struct workqueue_struct *target_submission_wq;
  45 static struct kmem_cache *se_sess_cache;
  46 struct kmem_cache *se_ua_cache;
  47 struct kmem_cache *t10_pr_reg_cache;
  48 struct kmem_cache *t10_alua_lu_gp_cache;
  49 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  50 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  51 struct kmem_cache *t10_alua_lba_map_cache;
  52 struct kmem_cache *t10_alua_lba_map_mem_cache;
  53
  54 static void transport_complete_task_attr(struct se_cmd *cmd);
  55 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
  56 static void transport_handle_queue_full(struct se_cmd *cmd,
  57                 struct se_device *dev, int err, bool write_pending);
  58 static void target_complete_ok_work(struct work_struct *work);
  59
  60 int init_se_kmem_caches(void)
  61 {
  62         se_sess_cache = kmem_cache_create("se_sess_cache",
  63                         sizeof(struct se_session), __alignof__(struct se_session),
  64                         0, NULL);
  65         if (!se_sess_cache) {
  66                 pr_err("kmem_cache_create() for struct se_session"
  67                                 " failed\n");
  68                 goto out;
  69         }
  70         se_ua_cache = kmem_cache_create("se_ua_cache",
  71                         sizeof(struct se_ua), __alignof__(struct se_ua),
  72                         0, NULL);
  73         if (!se_ua_cache) {
  74                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  75                 goto out_free_sess_cache;
  76         }
  77         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  78                         sizeof(struct t10_pr_registration),
  79                         __alignof__(struct t10_pr_registration), 0, NULL);
  80         if (!t10_pr_reg_cache) {
  81                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  82                                 " failed\n");
  83                 goto out_free_ua_cache;
  84         }
  85         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  86                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  87                         0, NULL);
  88         if (!t10_alua_lu_gp_cache) {
  89                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
  90                                 " failed\n");
  91                 goto out_free_pr_reg_cache;
  92         }
  93         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
  94                         sizeof(struct t10_alua_lu_gp_member),
  95                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
  96         if (!t10_alua_lu_gp_mem_cache) {
  97                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
  98                                 "cache failed\n");
  99                 goto out_free_lu_gp_cache;
 100         }
 101         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 102                         sizeof(struct t10_alua_tg_pt_gp),
 103                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 104         if (!t10_alua_tg_pt_gp_cache) {
 105                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 106                                 "cache failed\n");
 107                 goto out_free_lu_gp_mem_cache;
 108         }
 109         t10_alua_lba_map_cache = kmem_cache_create(
 110                         "t10_alua_lba_map_cache",
 111                         sizeof(struct t10_alua_lba_map),
 112                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 113         if (!t10_alua_lba_map_cache) {
 114                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 115                                 "cache failed\n");
 116                 goto out_free_tg_pt_gp_cache;
 117         }
 118         t10_alua_lba_map_mem_cache = kmem_cache_create(
 119                         "t10_alua_lba_map_mem_cache",
 120                         sizeof(struct t10_alua_lba_map_member),
 121                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 122         if (!t10_alua_lba_map_mem_cache) {
 123                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 124                                 "cache failed\n");
 125                 goto out_free_lba_map_cache;
 126         }
 127
 128         target_completion_wq = alloc_workqueue("target_completion",
 129                                                WQ_MEM_RECLAIM, 0);
 130         if (!target_completion_wq)
 131                 goto out_free_lba_map_mem_cache;
 132
 133         target_submission_wq = alloc_workqueue("target_submission",
 134                                                WQ_MEM_RECLAIM, 0);
 135         if (!target_submission_wq)
 136                 goto out_free_completion_wq;
 137
 138         return 0;
 139
 140 out_free_completion_wq:
 141         destroy_workqueue(target_completion_wq);
 142 out_free_lba_map_mem_cache:
 143         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 144 out_free_lba_map_cache:
 145         kmem_cache_destroy(t10_alua_lba_map_cache);
 146 out_free_tg_pt_gp_cache:
 147         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 148 out_free_lu_gp_mem_cache:
 149         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 150 out_free_lu_gp_cache:
 151         kmem_cache_destroy(t10_alua_lu_gp_cache);
 152 out_free_pr_reg_cache:
 153         kmem_cache_destroy(t10_pr_reg_cache);
 154 out_free_ua_cache:
 155         kmem_cache_destroy(se_ua_cache);
 156 out_free_sess_cache:
 157         kmem_cache_destroy(se_sess_cache);
 158 out:
 159         return -ENOMEM;
 160 }
 161
 162 void release_se_kmem_caches(void)
 163 {
 164         destroy_workqueue(target_submission_wq);
 165         destroy_workqueue(target_completion_wq);
 166         kmem_cache_destroy(se_sess_cache);
 167         kmem_cache_destroy(se_ua_cache);
 168         kmem_cache_destroy(t10_pr_reg_cache);
 169         kmem_cache_destroy(t10_alua_lu_gp_cache);
 170         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 171         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 172         kmem_cache_destroy(t10_alua_lba_map_cache);
 173         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 174 }
 175
 176 /* This code ensures unique mib indexes are handed out. */
 177 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 178 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 179
 180 /*
 181  * Allocate a new row index for the entry type specified
 182  */
 183 u32 scsi_get_new_index(scsi_index_t type)
 184 {
 185         u32 new_index;
 186
 187         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 188
 189         spin_lock(&scsi_mib_index_lock);
 190         new_index = ++scsi_mib_index[type];
 191         spin_unlock(&scsi_mib_index_lock);
 192
 193         return new_index;
 194 }
 195
 196 void transport_subsystem_check_init(void)
 197 {
 198         int ret;
 199         static int sub_api_initialized;
 200
 201         if (sub_api_initialized)
 202                 return;
 203
 204         ret = IS_ENABLED(CONFIG_TCM_IBLOCK) && request_module("target_core_iblock");
 205         if (ret != 0)
 206                 pr_err("Unable to load target_core_iblock\n");
 207
 208         ret = IS_ENABLED(CONFIG_TCM_FILEIO) && request_module("target_core_file");
 209         if (ret != 0)
 210                 pr_err("Unable to load target_core_file\n");
 211
 212         ret = IS_ENABLED(CONFIG_TCM_PSCSI) && request_module("target_core_pscsi");
 213         if (ret != 0)
 214                 pr_err("Unable to load target_core_pscsi\n");
 215
 216         ret = IS_ENABLED(CONFIG_TCM_USER2) && request_module("target_core_user");
 217         if (ret != 0)
 218                 pr_err("Unable to load target_core_user\n");
 219
 220         sub_api_initialized = 1;
 221 }
 222
 223 static void target_release_cmd_refcnt(struct percpu_ref *ref)
 224 {
 225         struct target_cmd_counter *cmd_cnt  = container_of(ref,
 226                                                            typeof(*cmd_cnt),
 227                                                            refcnt);
 228         wake_up(&cmd_cnt->refcnt_wq);
 229 }
 230
 231 struct target_cmd_counter *target_alloc_cmd_counter(void)
 232 {
 233         struct target_cmd_counter *cmd_cnt;
 234         int rc;
 235
 236         cmd_cnt = kzalloc(sizeof(*cmd_cnt), GFP_KERNEL);
 237         if (!cmd_cnt)
 238                 return NULL;
 239
 240         init_completion(&cmd_cnt->stop_done);
 241         init_waitqueue_head(&cmd_cnt->refcnt_wq);
 242         atomic_set(&cmd_cnt->stopped, 0);
 243
 244         rc = percpu_ref_init(&cmd_cnt->refcnt, target_release_cmd_refcnt, 0,
 245                              GFP_KERNEL);
 246         if (rc)
 247                 goto free_cmd_cnt;
 248
 249         return cmd_cnt;
 250
 251 free_cmd_cnt:
 252         kfree(cmd_cnt);
 253         return NULL;
 254 }
 255 EXPORT_SYMBOL_GPL(target_alloc_cmd_counter);
 256
 257 void target_free_cmd_counter(struct target_cmd_counter *cmd_cnt)
 258 {
 259         /*
 260          * Drivers like loop do not call target_stop_session during session
 261          * shutdown so we have to drop the ref taken at init time here.
 262          */
 263         if (!atomic_read(&cmd_cnt->stopped))
 264                 percpu_ref_put(&cmd_cnt->refcnt);
 265
 266         percpu_ref_exit(&cmd_cnt->refcnt);
 267         kfree(cmd_cnt);
 268 }
 269 EXPORT_SYMBOL_GPL(target_free_cmd_counter);
 270
 271 /**
 272  * transport_init_session - initialize a session object
 273  * @se_sess: Session object pointer.
 274  *
 275  * The caller must have zero-initialized @se_sess before calling this function.
 276  */
 277 void transport_init_session(struct se_session *se_sess)
 278 {
 279         INIT_LIST_HEAD(&se_sess->sess_list);
 280         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 281         spin_lock_init(&se_sess->sess_cmd_lock);
 282 }
 283 EXPORT_SYMBOL(transport_init_session);
 284
 285 /**
 286  * transport_alloc_session - allocate a session object and initialize it
 287  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
 288  */
 289 struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
 290 {
 291         struct se_session *se_sess;
 292
 293         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 294         if (!se_sess) {
 295                 pr_err("Unable to allocate struct se_session from"
 296                                 " se_sess_cache\n");
 297                 return ERR_PTR(-ENOMEM);
 298         }
 299         transport_init_session(se_sess);
 300         se_sess->sup_prot_ops = sup_prot_ops;
 301
 302         return se_sess;
 303 }
 304 EXPORT_SYMBOL(transport_alloc_session);
 305
 306 /**
 307  * transport_alloc_session_tags - allocate target driver private data
 308  * @se_sess:  Session pointer.
 309  * @tag_num:  Maximum number of in-flight commands between initiator and target.
 310  * @tag_size: Size in bytes of the private data a target driver associates with
 311  *            each command.
 312  */
 313 int transport_alloc_session_tags(struct se_session *se_sess,
 314                                  unsigned int tag_num, unsigned int tag_size)
 315 {
 316         int rc;
 317
 318         se_sess->sess_cmd_map = kvcalloc(tag_size, tag_num,
 319                                          GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 320         if (!se_sess->sess_cmd_map) {
 321                 pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 322                 return -ENOMEM;
 323         }
 324
 325         rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
 326                         false, GFP_KERNEL, NUMA_NO_NODE);
 327         if (rc < 0) {
 328                 pr_err("Unable to init se_sess->sess_tag_pool,"
 329                         " tag_num: %u\n", tag_num);
 330                 kvfree(se_sess->sess_cmd_map);
 331                 se_sess->sess_cmd_map = NULL;
 332                 return -ENOMEM;
 333         }
 334
 335         return 0;
 336 }
 337 EXPORT_SYMBOL(transport_alloc_session_tags);
 338
 339 /**
 340  * transport_init_session_tags - allocate a session and target driver private data
 341  * @tag_num:  Maximum number of in-flight commands between initiator and target.
 342  * @tag_size: Size in bytes of the private data a target driver associates with
 343  *            each command.
 344  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
 345  */
 346 static struct se_session *
 347 transport_init_session_tags(unsigned int tag_num, unsigned int tag_size,
 348                             enum target_prot_op sup_prot_ops)
 349 {
 350         struct se_session *se_sess;
 351         int rc;
 352
 353         if (tag_num != 0 && !tag_size) {
 354                 pr_err("init_session_tags called with percpu-ida tag_num:"
 355                        " %u, but zero tag_size\n", tag_num);
 356                 return ERR_PTR(-EINVAL);
 357         }
 358         if (!tag_num && tag_size) {
 359                 pr_err("init_session_tags called with percpu-ida tag_size:"
 360                        " %u, but zero tag_num\n", tag_size);
 361                 return ERR_PTR(-EINVAL);
 362         }
 363
 364         se_sess = transport_alloc_session(sup_prot_ops);
 365         if (IS_ERR(se_sess))
 366                 return se_sess;
 367
 368         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 369         if (rc < 0) {
 370                 transport_free_session(se_sess);
 371                 return ERR_PTR(-ENOMEM);
 372         }
 373
 374         return se_sess;
 375 }
 376
 377 /*
 378  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 379  */
 380 void __transport_register_session(
 381         struct se_portal_group *se_tpg,
 382         struct se_node_acl *se_nacl,
 383         struct se_session *se_sess,
 384         void *fabric_sess_ptr)
 385 {
 386         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 387         unsigned char buf[PR_REG_ISID_LEN];
 388         unsigned long flags;
 389
 390         se_sess->se_tpg = se_tpg;
 391         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 392         /*
 393          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 394          *
 395          * Only set for struct se_session's that will actually be moving I/O.
 396          * eg: *NOT* discovery sessions.
 397          */
 398         if (se_nacl) {
 399                 /*
 400                  *
 401                  * Determine if fabric allows for T10-PI feature bits exposed to
 402                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 403                  *
 404                  * If so, then always save prot_type on a per se_node_acl node
 405                  * basis and re-instate the previous sess_prot_type to avoid
 406                  * disabling PI from below any previously initiator side
 407                  * registered LUNs.
 408                  */
 409                 if (se_nacl->saved_prot_type)
 410                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 411                 else if (tfo->tpg_check_prot_fabric_only)
 412                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 413                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 414                 /*
 415                  * If the fabric module supports an ISID based TransportID,
 416                  * save this value in binary from the fabric I_T Nexus now.
 417                  */
 418                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 419                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 420                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 421                                         &buf[0], PR_REG_ISID_LEN);
 422                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 423                 }
 424
 425                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 426                 /*
 427                  * The se_nacl->nacl_sess pointer will be set to the
 428                  * last active I_T Nexus for each struct se_node_acl.
 429                  */
 430                 se_nacl->nacl_sess = se_sess;
 431
 432                 list_add_tail(&se_sess->sess_acl_list,
 433                               &se_nacl->acl_sess_list);
 434                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 435         }
 436         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 437
 438         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 439                 se_tpg->se_tpg_tfo->fabric_name, se_sess->fabric_sess_ptr);
 440 }
 441 EXPORT_SYMBOL(__transport_register_session);
 442
 443 void transport_register_session(
 444         struct se_portal_group *se_tpg,
 445         struct se_node_acl *se_nacl,
 446         struct se_session *se_sess,
 447         void *fabric_sess_ptr)
 448 {
 449         unsigned long flags;
 450
 451         spin_lock_irqsave(&se_tpg->session_lock, flags);
 452         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 453         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 454 }
 455 EXPORT_SYMBOL(transport_register_session);
 456
 457 struct se_session *
 458 target_setup_session(struct se_portal_group *tpg,
 459                      unsigned int tag_num, unsigned int tag_size,
 460                      enum target_prot_op prot_op,
 461                      const char *initiatorname, void *private,
 462                      int (*callback)(struct se_portal_group *,
 463                                      struct se_session *, void *))
 464 {
 465         struct target_cmd_counter *cmd_cnt;
 466         struct se_session *sess;
 467         int rc;
 468
 469         cmd_cnt = target_alloc_cmd_counter();
 470         if (!cmd_cnt)
 471                 return ERR_PTR(-ENOMEM);
 472         /*
 473          * If the fabric driver is using percpu-ida based pre allocation
 474          * of I/O descriptor tags, go ahead and perform that setup now..
 475          */
 476         if (tag_num != 0)
 477                 sess = transport_init_session_tags(tag_num, tag_size, prot_op);
 478         else
 479                 sess = transport_alloc_session(prot_op);
 480
 481         if (IS_ERR(sess)) {
 482                 rc = PTR_ERR(sess);
 483                 goto free_cnt;
 484         }
 485         sess->cmd_cnt = cmd_cnt;
 486
 487         sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
 488                                         (unsigned char *)initiatorname);
 489         if (!sess->se_node_acl) {
 490                 rc = -EACCES;
 491                 goto free_sess;
 492         }
 493         /*
 494          * Go ahead and perform any remaining fabric setup that is
 495          * required before transport_register_session().
 496          */
 497         if (callback != NULL) {
 498                 rc = callback(tpg, sess, private);
 499                 if (rc)
 500                         goto free_sess;
 501         }
 502
 503         transport_register_session(tpg, sess->se_node_acl, sess, private);
 504         return sess;
 505
 506 free_sess:
 507         transport_free_session(sess);
 508         return ERR_PTR(rc);
 509
 510 free_cnt:
 511         target_free_cmd_counter(cmd_cnt);
 512         return ERR_PTR(rc);
 513 }
 514 EXPORT_SYMBOL(target_setup_session);
 515
 516 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 517 {
 518         struct se_session *se_sess;
 519         ssize_t len = 0;
 520
 521         spin_lock_bh(&se_tpg->session_lock);
 522         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 523                 if (!se_sess->se_node_acl)
 524                         continue;
 525                 if (!se_sess->se_node_acl->dynamic_node_acl)
 526                         continue;
 527                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 528                         break;
 529
 530                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 531                                 se_sess->se_node_acl->initiatorname);
 532                 len += 1; /* Include NULL terminator */
 533         }
 534         spin_unlock_bh(&se_tpg->session_lock);
 535
 536         return len;
 537 }
 538 EXPORT_SYMBOL(target_show_dynamic_sessions);
 539
 540 static void target_complete_nacl(struct kref *kref)
 541 {
 542         struct se_node_acl *nacl = container_of(kref,
 543                                 struct se_node_acl, acl_kref);
 544         struct se_portal_group *se_tpg = nacl->se_tpg;
 545
 546         if (!nacl->dynamic_stop) {
 547                 complete(&nacl->acl_free_comp);
 548                 return;
 549         }
 550
 551         mutex_lock(&se_tpg->acl_node_mutex);
 552         list_del_init(&nacl->acl_list);
 553         mutex_unlock(&se_tpg->acl_node_mutex);
 554
 555         core_tpg_wait_for_nacl_pr_ref(nacl);
 556         core_free_device_list_for_node(nacl, se_tpg);
 557         kfree(nacl);
 558 }
 559
 560 void target_put_nacl(struct se_node_acl *nacl)
 561 {
 562         kref_put(&nacl->acl_kref, target_complete_nacl);
 563 }
 564 EXPORT_SYMBOL(target_put_nacl);
 565
 566 void transport_deregister_session_configfs(struct se_session *se_sess)
 567 {
 568         struct se_node_acl *se_nacl;
 569         unsigned long flags;
 570         /*
 571          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 572          */
 573         se_nacl = se_sess->se_node_acl;
 574         if (se_nacl) {
 575                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 576                 if (!list_empty(&se_sess->sess_acl_list))
 577                         list_del_init(&se_sess->sess_acl_list);
 578                 /*
 579                  * If the session list is empty, then clear the pointer.
 580                  * Otherwise, set the struct se_session pointer from the tail
 581                  * element of the per struct se_node_acl active session list.
 582                  */
 583                 if (list_empty(&se_nacl->acl_sess_list))
 584                         se_nacl->nacl_sess = NULL;
 585                 else {
 586                         se_nacl->nacl_sess = container_of(
 587                                         se_nacl->acl_sess_list.prev,
 588                                         struct se_session, sess_acl_list);
 589                 }
 590                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 591         }
 592 }
 593 EXPORT_SYMBOL(transport_deregister_session_configfs);
 594
 595 void transport_free_session(struct se_session *se_sess)
 596 {
 597         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 598
 599         /*
 600          * Drop the se_node_acl->nacl_kref obtained from within
 601          * core_tpg_get_initiator_node_acl().
 602          */
 603         if (se_nacl) {
 604                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 605                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 606                 unsigned long flags;
 607
 608                 se_sess->se_node_acl = NULL;
 609
 610                 /*
 611                  * Also determine if we need to drop the extra ->cmd_kref if
 612                  * it had been previously dynamically generated, and
 613                  * the endpoint is not caching dynamic ACLs.
 614                  */
 615                 mutex_lock(&se_tpg->acl_node_mutex);
 616                 if (se_nacl->dynamic_node_acl &&
 617                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 618                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 619                         if (list_empty(&se_nacl->acl_sess_list))
 620                                 se_nacl->dynamic_stop = true;
 621                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 622
 623                         if (se_nacl->dynamic_stop)
 624                                 list_del_init(&se_nacl->acl_list);
 625                 }
 626                 mutex_unlock(&se_tpg->acl_node_mutex);
 627
 628                 if (se_nacl->dynamic_stop)
 629                         target_put_nacl(se_nacl);
 630
 631                 target_put_nacl(se_nacl);
 632         }
 633         if (se_sess->sess_cmd_map) {
 634                 sbitmap_queue_free(&se_sess->sess_tag_pool);
 635                 kvfree(se_sess->sess_cmd_map);
 636         }
 637         if (se_sess->cmd_cnt)
 638                 target_free_cmd_counter(se_sess->cmd_cnt);
 639         kmem_cache_free(se_sess_cache, se_sess);
 640 }
 641 EXPORT_SYMBOL(transport_free_session);
 642
 643 static int target_release_res(struct se_device *dev, void *data)
 644 {
 645         struct se_session *sess = data;
 646
 647         if (dev->reservation_holder == sess)
 648                 target_release_reservation(dev);
 649         return 0;
 650 }
 651
 652 void transport_deregister_session(struct se_session *se_sess)
 653 {
 654         struct se_portal_group *se_tpg = se_sess->se_tpg;
 655         unsigned long flags;
 656
 657         if (!se_tpg) {
 658                 transport_free_session(se_sess);
 659                 return;
 660         }
 661
 662         spin_lock_irqsave(&se_tpg->session_lock, flags);
 663         list_del(&se_sess->sess_list);
 664         se_sess->se_tpg = NULL;
 665         se_sess->fabric_sess_ptr = NULL;
 666         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 667
 668         /*
 669          * Since the session is being removed, release SPC-2
 670          * reservations held by the session that is disappearing.
 671          */
 672         target_for_each_device(target_release_res, se_sess);
 673
 674         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 675                 se_tpg->se_tpg_tfo->fabric_name);
 676         /*
 677          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 678          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 679          * removal context from within transport_free_session() code.
 680          *
 681          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 682          * to release all remaining generate_node_acl=1 created ACL resources.
 683          */
 684
 685         transport_free_session(se_sess);
 686 }
 687 EXPORT_SYMBOL(transport_deregister_session);
 688
 689 void target_remove_session(struct se_session *se_sess)
 690 {
 691         transport_deregister_session_configfs(se_sess);
 692         transport_deregister_session(se_sess);
 693 }
 694 EXPORT_SYMBOL(target_remove_session);
 695
 696 static void target_remove_from_state_list(struct se_cmd *cmd)
 697 {
 698         struct se_device *dev = cmd->se_dev;
 699         unsigned long flags;
 700
 701         if (!dev)
 702                 return;
 703
 704         spin_lock_irqsave(&dev->queues[cmd->cpuid].lock, flags);
 705         if (cmd->state_active) {
 706                 list_del(&cmd->state_list);
 707                 cmd->state_active = false;
 708         }
 709         spin_unlock_irqrestore(&dev->queues[cmd->cpuid].lock, flags);
 710 }
 711
 712 static void target_remove_from_tmr_list(struct se_cmd *cmd)
 713 {
 714         struct se_device *dev = NULL;
 715         unsigned long flags;
 716
 717         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
 718                 dev = cmd->se_tmr_req->tmr_dev;
 719
 720         if (dev) {
 721                 spin_lock_irqsave(&dev->se_tmr_lock, flags);
 722                 if (cmd->se_tmr_req->tmr_dev)
 723                         list_del_init(&cmd->se_tmr_req->tmr_list);
 724                 spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
 725         }
 726 }
 727 /*
 728  * This function is called by the target core after the target core has
 729  * finished processing a SCSI command or SCSI TMF. Both the regular command
 730  * processing code and the code for aborting commands can call this
 731  * function. CMD_T_STOP is set if and only if another thread is waiting
 732  * inside transport_wait_for_tasks() for t_transport_stop_comp.
 733  */
 734 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 735 {
 736         unsigned long flags;
 737
 738         spin_lock_irqsave(&cmd->t_state_lock, flags);
 739         /*
 740          * Determine if frontend context caller is requesting the stopping of
 741          * this command for frontend exceptions.
 742          */
 743         if (cmd->transport_state & CMD_T_STOP) {
 744                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 745                         __func__, __LINE__, cmd->tag);
 746
 747                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 748
 749                 complete_all(&cmd->t_transport_stop_comp);
 750                 return 1;
 751         }
 752         cmd->transport_state &= ~CMD_T_ACTIVE;
 753         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 754
 755         /*
 756          * Some fabric modules like tcm_loop can release their internally
 757          * allocated I/O reference and struct se_cmd now.
 758          *
 759          * Fabric modules are expected to return '1' here if the se_cmd being
 760          * passed is released at this point, or zero if not being released.
 761          */
 762         return cmd->se_tfo->check_stop_free(cmd);
 763 }
 764
 765 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 766 {
 767         struct se_lun *lun = cmd->se_lun;
 768
 769         if (!lun)
 770                 return;
 771
 772         target_remove_from_state_list(cmd);
 773         target_remove_from_tmr_list(cmd);
 774
 775         if (cmpxchg(&cmd->lun_ref_active, true, false))
 776                 percpu_ref_put(&lun->lun_ref);
 777
 778         /*
 779          * Clear struct se_cmd->se_lun before the handoff to FE.
 780          */
 781         cmd->se_lun = NULL;
 782 }
 783
 784 static void target_complete_failure_work(struct work_struct *work)
 785 {
 786         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 787
 788         transport_generic_request_failure(cmd, cmd->sense_reason);
 789 }
 790
 791 /*
 792  * Used when asking transport to copy Sense Data from the underlying
 793  * Linux/SCSI struct scsi_cmnd
 794  */
 795 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 796 {
 797         struct se_device *dev = cmd->se_dev;
 798
 799         WARN_ON(!cmd->se_lun);
 800
 801         if (!dev)
 802                 return NULL;
 803
 804         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 805                 return NULL;
 806
 807         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 808
 809         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 810                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 811         return cmd->sense_buffer;
 812 }
 813
 814 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
 815 {
 816         unsigned char *cmd_sense_buf;
 817         unsigned long flags;
 818
 819         spin_lock_irqsave(&cmd->t_state_lock, flags);
 820         cmd_sense_buf = transport_get_sense_buffer(cmd);
 821         if (!cmd_sense_buf) {
 822                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 823                 return;
 824         }
 825
 826         cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
 827         memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
 828         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 829 }
 830 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
 831
 832 static void target_handle_abort(struct se_cmd *cmd)
 833 {
 834         bool tas = cmd->transport_state & CMD_T_TAS;
 835         bool ack_kref = cmd->se_cmd_flags & SCF_ACK_KREF;
 836         int ret;
 837
 838         pr_debug("tag %#llx: send_abort_response = %d\n", cmd->tag, tas);
 839
 840         if (tas) {
 841                 if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
 842                         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
 843                         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
 844                                  cmd->t_task_cdb[0], cmd->tag);
 845                         trace_target_cmd_complete(cmd);
 846                         ret = cmd->se_tfo->queue_status(cmd);
 847                         if (ret) {
 848                                 transport_handle_queue_full(cmd, cmd->se_dev,
 849                                                             ret, false);
 850                                 return;
 851                         }
 852                 } else {
 853                         cmd->se_tmr_req->response = TMR_FUNCTION_REJECTED;
 854                         cmd->se_tfo->queue_tm_rsp(cmd);
 855                 }
 856         } else {
 857                 /*
 858                  * Allow the fabric driver to unmap any resources before
 859                  * releasing the descriptor via TFO->release_cmd().
 860                  */
 861                 cmd->se_tfo->aborted_task(cmd);
 862                 if (ack_kref)
 863                         WARN_ON_ONCE(target_put_sess_cmd(cmd) != 0);
 864                 /*
 865                  * To do: establish a unit attention condition on the I_T
 866                  * nexus associated with cmd. See also the paragraph "Aborting
 867                  * commands" in SAM.
 868                  */
 869         }
 870
 871         WARN_ON_ONCE(kref_read(&cmd->cmd_kref) == 0);
 872
 873         transport_lun_remove_cmd(cmd);
 874
 875         transport_cmd_check_stop_to_fabric(cmd);
 876 }
 877
 878 static void target_abort_work(struct work_struct *work)
 879 {
 880         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 881
 882         target_handle_abort(cmd);
 883 }
 884
 885 static bool target_cmd_interrupted(struct se_cmd *cmd)
 886 {
 887         int post_ret;
 888
 889         if (cmd->transport_state & CMD_T_ABORTED) {
 890                 if (cmd->transport_complete_callback)
 891                         cmd->transport_complete_callback(cmd, false, &post_ret);
 892                 INIT_WORK(&cmd->work, target_abort_work);
 893                 queue_work(target_completion_wq, &cmd->work);
 894                 return true;
 895         } else if (cmd->transport_state & CMD_T_STOP) {
 896                 if (cmd->transport_complete_callback)
 897                         cmd->transport_complete_callback(cmd, false, &post_ret);
 898                 complete_all(&cmd->t_transport_stop_comp);
 899                 return true;
 900         }
 901
 902         return false;
 903 }
 904
 905 /* May be called from interrupt context so must not sleep. */
 906 void target_complete_cmd_with_sense(struct se_cmd *cmd, u8 scsi_status,
 907                                     sense_reason_t sense_reason)
 908 {
 909         struct se_wwn *wwn = cmd->se_sess->se_tpg->se_tpg_wwn;
 910         int success, cpu;
 911         unsigned long flags;
 912
 913         if (target_cmd_interrupted(cmd))
 914                 return;
 915
 916         cmd->scsi_status = scsi_status;
 917         cmd->sense_reason = sense_reason;
 918
 919         spin_lock_irqsave(&cmd->t_state_lock, flags);
 920         switch (cmd->scsi_status) {
 921         case SAM_STAT_CHECK_CONDITION:
 922                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 923                         success = 1;
 924                 else
 925                         success = 0;
 926                 break;
 927         default:
 928                 success = 1;
 929                 break;
 930         }
 931
 932         cmd->t_state = TRANSPORT_COMPLETE;
 933         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 934         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 935
 936         INIT_WORK(&cmd->work, success ? target_complete_ok_work :
 937                   target_complete_failure_work);
 938
 939         if (!wwn || wwn->cmd_compl_affinity == SE_COMPL_AFFINITY_CPUID)
 940                 cpu = cmd->cpuid;
 941         else
 942                 cpu = wwn->cmd_compl_affinity;
 943
 944         queue_work_on(cpu, target_completion_wq, &cmd->work);
 945 }
 946 EXPORT_SYMBOL(target_complete_cmd_with_sense);
 947
 948 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 949 {
 950         target_complete_cmd_with_sense(cmd, scsi_status, scsi_status ?
 951                               TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE :
 952                               TCM_NO_SENSE);
 953 }
 954 EXPORT_SYMBOL(target_complete_cmd);
 955
 956 void target_set_cmd_data_length(struct se_cmd *cmd, int length)
 957 {
 958         if (length < cmd->data_length) {
 959                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 960                         cmd->residual_count += cmd->data_length - length;
 961                 } else {
 962                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 963                         cmd->residual_count = cmd->data_length - length;
 964                 }
 965
 966                 cmd->data_length = length;
 967         }
 968 }
 969 EXPORT_SYMBOL(target_set_cmd_data_length);
 970
 971 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 972 {
 973         if (scsi_status == SAM_STAT_GOOD ||
 974             cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) {
 975                 target_set_cmd_data_length(cmd, length);
 976         }
 977
 978         target_complete_cmd(cmd, scsi_status);
 979 }
 980 EXPORT_SYMBOL(target_complete_cmd_with_length);
 981
 982 static void target_add_to_state_list(struct se_cmd *cmd)
 983 {
 984         struct se_device *dev = cmd->se_dev;
 985         unsigned long flags;
 986
 987         spin_lock_irqsave(&dev->queues[cmd->cpuid].lock, flags);
 988         if (!cmd->state_active) {
 989                 list_add_tail(&cmd->state_list,
 990                               &dev->queues[cmd->cpuid].state_list);
 991                 cmd->state_active = true;
 992         }
 993         spin_unlock_irqrestore(&dev->queues[cmd->cpuid].lock, flags);
 994 }
 995
 996 /*
 997  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 998  */
 999 static void transport_write_pending_qf(struct se_cmd *cmd);
1000 static void transport_complete_qf(struct se_cmd *cmd);
1001
1002 void target_qf_do_work(struct work_struct *work)
1003 {
1004         struct se_device *dev = container_of(work, struct se_device,
1005                                         qf_work_queue);
1006         LIST_HEAD(qf_cmd_list);
1007         struct se_cmd *cmd, *cmd_tmp;
1008
1009         spin_lock_irq(&dev->qf_cmd_lock);
1010         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
1011         spin_unlock_irq(&dev->qf_cmd_lock);
1012
1013         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
1014                 list_del(&cmd->se_qf_node);
1015                 atomic_dec_mb(&dev->dev_qf_count);
1016
1017                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
1018                         " context: %s\n", cmd->se_tfo->fabric_name, cmd,
1019                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
1020                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
1021                         : "UNKNOWN");
1022
1023                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
1024                         transport_write_pending_qf(cmd);
1025                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
1026                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
1027                         transport_complete_qf(cmd);
1028         }
1029 }
1030
1031 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
1032 {
1033         switch (cmd->data_direction) {
1034         case DMA_NONE:
1035                 return "NONE";
1036         case DMA_FROM_DEVICE:
1037                 return "READ";
1038         case DMA_TO_DEVICE:
1039                 return "WRITE";
1040         case DMA_BIDIRECTIONAL:
1041                 return "BIDI";
1042         default:
1043                 break;
1044         }
1045
1046         return "UNKNOWN";
1047 }
1048
1049 void transport_dump_dev_state(
1050         struct se_device *dev,
1051         char *b,
1052         int *bl)
1053 {
1054         *bl += sprintf(b + *bl, "Status: ");
1055         if (dev->export_count)
1056                 *bl += sprintf(b + *bl, "ACTIVATED");
1057         else
1058                 *bl += sprintf(b + *bl, "DEACTIVATED");
1059
1060         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
1061         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
1062                 dev->dev_attrib.block_size,
1063                 dev->dev_attrib.hw_max_sectors);
1064         *bl += sprintf(b + *bl, "        ");
1065 }
1066
1067 void transport_dump_vpd_proto_id(
1068         struct t10_vpd *vpd,
1069         unsigned char *p_buf,
1070         int p_buf_len)
1071 {
1072         unsigned char buf[VPD_TMP_BUF_SIZE];
1073         int len;
1074
1075         memset(buf, 0, VPD_TMP_BUF_SIZE);
1076         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
1077
1078         switch (vpd->protocol_identifier) {
1079         case 0x00:
1080                 sprintf(buf+len, "Fibre Channel\n");
1081                 break;
1082         case 0x10:
1083                 sprintf(buf+len, "Parallel SCSI\n");
1084                 break;
1085         case 0x20:
1086                 sprintf(buf+len, "SSA\n");
1087                 break;
1088         case 0x30:
1089                 sprintf(buf+len, "IEEE 1394\n");
1090                 break;
1091         case 0x40:
1092                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
1093                                 " Protocol\n");
1094                 break;
1095         case 0x50:
1096                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
1097                 break;
1098         case 0x60:
1099                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
1100                 break;
1101         case 0x70:
1102                 sprintf(buf+len, "Automation/Drive Interface Transport"
1103                                 " Protocol\n");
1104                 break;
1105         case 0x80:
1106                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
1107                 break;
1108         default:
1109                 sprintf(buf+len, "Unknown 0x%02x\n",
1110                                 vpd->protocol_identifier);
1111                 break;
1112         }
1113
1114         if (p_buf)
1115                 strncpy(p_buf, buf, p_buf_len);
1116         else
1117                 pr_debug("%s", buf);
1118 }
1119
1120 void
1121 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
1122 {
1123         /*
1124          * Check if the Protocol Identifier Valid (PIV) bit is set..
1125          *
1126          * from spc3r23.pdf section 7.5.1
1127          */
1128          if (page_83[1] & 0x80) {
1129                 vpd->protocol_identifier = (page_83[0] & 0xf0);
1130                 vpd->protocol_identifier_set = 1;
1131                 transport_dump_vpd_proto_id(vpd, NULL, 0);
1132         }
1133 }
1134 EXPORT_SYMBOL(transport_set_vpd_proto_id);
1135
1136 int transport_dump_vpd_assoc(
1137         struct t10_vpd *vpd,
1138         unsigned char *p_buf,
1139         int p_buf_len)
1140 {
1141         unsigned char buf[VPD_TMP_BUF_SIZE];
1142         int ret = 0;
1143         int len;
1144
1145         memset(buf, 0, VPD_TMP_BUF_SIZE);
1146         len = sprintf(buf, "T10 VPD Identifier Association: ");
1147
1148         switch (vpd->association) {
1149         case 0x00:
1150                 sprintf(buf+len, "addressed logical unit\n");
1151                 break;
1152         case 0x10:
1153                 sprintf(buf+len, "target port\n");
1154                 break;
1155         case 0x20:
1156                 sprintf(buf+len, "SCSI target device\n");
1157                 break;
1158         default:
1159                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
1160                 ret = -EINVAL;
1161                 break;
1162         }
1163
1164         if (p_buf)
1165                 strncpy(p_buf, buf, p_buf_len);
1166         else
1167                 pr_debug("%s", buf);
1168
1169         return ret;
1170 }
1171
1172 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
1173 {
1174         /*
1175          * The VPD identification association..
1176          *
1177          * from spc3r23.pdf Section 7.6.3.1 Table 297
1178          */
1179         vpd->association = (page_83[1] & 0x30);
1180         return transport_dump_vpd_assoc(vpd, NULL, 0);
1181 }
1182 EXPORT_SYMBOL(transport_set_vpd_assoc);
1183
1184 int transport_dump_vpd_ident_type(
1185         struct t10_vpd *vpd,
1186         unsigned char *p_buf,
1187         int p_buf_len)
1188 {
1189         unsigned char buf[VPD_TMP_BUF_SIZE];
1190         int ret = 0;
1191         int len;
1192
1193         memset(buf, 0, VPD_TMP_BUF_SIZE);
1194         len = sprintf(buf, "T10 VPD Identifier Type: ");
1195
1196         switch (vpd->device_identifier_type) {
1197         case 0x00:
1198                 sprintf(buf+len, "Vendor specific\n");
1199                 break;
1200         case 0x01:
1201                 sprintf(buf+len, "T10 Vendor ID based\n");
1202                 break;
1203         case 0x02:
1204                 sprintf(buf+len, "EUI-64 based\n");
1205                 break;
1206         case 0x03:
1207                 sprintf(buf+len, "NAA\n");
1208                 break;
1209         case 0x04:
1210                 sprintf(buf+len, "Relative target port identifier\n");
1211                 break;
1212         case 0x08:
1213                 sprintf(buf+len, "SCSI name string\n");
1214                 break;
1215         default:
1216                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1217                                 vpd->device_identifier_type);
1218                 ret = -EINVAL;
1219                 break;
1220         }
1221
1222         if (p_buf) {
1223                 if (p_buf_len < strlen(buf)+1)
1224                         return -EINVAL;
1225                 strncpy(p_buf, buf, p_buf_len);
1226         } else {
1227                 pr_debug("%s", buf);
1228         }
1229
1230         return ret;
1231 }
1232
1233 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1234 {
1235         /*
1236          * The VPD identifier type..
1237          *
1238          * from spc3r23.pdf Section 7.6.3.1 Table 298
1239          */
1240         vpd->device_identifier_type = (page_83[1] & 0x0f);
1241         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1242 }
1243 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1244
1245 int transport_dump_vpd_ident(
1246         struct t10_vpd *vpd,
1247         unsigned char *p_buf,
1248         int p_buf_len)
1249 {
1250         unsigned char buf[VPD_TMP_BUF_SIZE];
1251         int ret = 0;
1252
1253         memset(buf, 0, VPD_TMP_BUF_SIZE);
1254
1255         switch (vpd->device_identifier_code_set) {
1256         case 0x01: /* Binary */
1257                 snprintf(buf, sizeof(buf),
1258                         "T10 VPD Binary Device Identifier: %s\n",
1259                         &vpd->device_identifier[0]);
1260                 break;
1261         case 0x02: /* ASCII */
1262                 snprintf(buf, sizeof(buf),
1263                         "T10 VPD ASCII Device Identifier: %s\n",
1264                         &vpd->device_identifier[0]);
1265                 break;
1266         case 0x03: /* UTF-8 */
1267                 snprintf(buf, sizeof(buf),
1268                         "T10 VPD UTF-8 Device Identifier: %s\n",
1269                         &vpd->device_identifier[0]);
1270                 break;
1271         default:
1272                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1273                         " 0x%02x", vpd->device_identifier_code_set);
1274                 ret = -EINVAL;
1275                 break;
1276         }
1277
1278         if (p_buf)
1279                 strncpy(p_buf, buf, p_buf_len);
1280         else
1281                 pr_debug("%s", buf);
1282
1283         return ret;
1284 }
1285
1286 int
1287 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1288 {
1289         static const char hex_str[] = "0123456789abcdef";
1290         int j = 0, i = 4; /* offset to start of the identifier */
1291
1292         /*
1293          * The VPD Code Set (encoding)
1294          *
1295          * from spc3r23.pdf Section 7.6.3.1 Table 296
1296          */
1297         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1298         switch (vpd->device_identifier_code_set) {
1299         case 0x01: /* Binary */
1300                 vpd->device_identifier[j++] =
1301                                 hex_str[vpd->device_identifier_type];
1302                 while (i < (4 + page_83[3])) {
1303                         vpd->device_identifier[j++] =
1304                                 hex_str[(page_83[i] & 0xf0) >> 4];
1305                         vpd->device_identifier[j++] =
1306                                 hex_str[page_83[i] & 0x0f];
1307                         i++;
1308                 }
1309                 break;
1310         case 0x02: /* ASCII */
1311         case 0x03: /* UTF-8 */
1312                 while (i < (4 + page_83[3]))
1313                         vpd->device_identifier[j++] = page_83[i++];
1314                 break;
1315         default:
1316                 break;
1317         }
1318
1319         return transport_dump_vpd_ident(vpd, NULL, 0);
1320 }
1321 EXPORT_SYMBOL(transport_set_vpd_ident);
1322
1323 static sense_reason_t
1324 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1325                                unsigned int size)
1326 {
1327         u32 mtl;
1328
1329         if (!cmd->se_tfo->max_data_sg_nents)
1330                 return TCM_NO_SENSE;
1331         /*
1332          * Check if fabric enforced maximum SGL entries per I/O descriptor
1333          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1334          * residual_count and reduce original cmd->data_length to maximum
1335          * length based on single PAGE_SIZE entry scatter-lists.
1336          */
1337         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1338         if (cmd->data_length > mtl) {
1339                 /*
1340                  * If an existing CDB overflow is present, calculate new residual
1341                  * based on CDB size minus fabric maximum transfer length.
1342                  *
1343                  * If an existing CDB underflow is present, calculate new residual
1344                  * based on original cmd->data_length minus fabric maximum transfer
1345                  * length.
1346                  *
1347                  * Otherwise, set the underflow residual based on cmd->data_length
1348                  * minus fabric maximum transfer length.
1349                  */
1350                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1351                         cmd->residual_count = (size - mtl);
1352                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1353                         u32 orig_dl = size + cmd->residual_count;
1354                         cmd->residual_count = (orig_dl - mtl);
1355                 } else {
1356                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1357                         cmd->residual_count = (cmd->data_length - mtl);
1358                 }
1359                 cmd->data_length = mtl;
1360                 /*
1361                  * Reset sbc_check_prot() calculated protection payload
1362                  * length based upon the new smaller MTL.
1363                  */
1364                 if (cmd->prot_length) {
1365                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1366                         cmd->prot_length = dev->prot_length * sectors;
1367                 }
1368         }
1369         return TCM_NO_SENSE;
1370 }
1371
1372 /**
1373  * target_cmd_size_check - Check whether there will be a residual.
1374  * @cmd: SCSI command.
1375  * @size: Data buffer size derived from CDB. The data buffer size provided by
1376  *   the SCSI transport driver is available in @cmd->data_length.
1377  *
1378  * Compare the data buffer size from the CDB with the data buffer limit from the transport
1379  * header. Set @cmd->residual_count and SCF_OVERFLOW_BIT or SCF_UNDERFLOW_BIT if necessary.
1380  *
1381  * Note: target drivers set @cmd->data_length by calling __target_init_cmd().
1382  *
1383  * Return: TCM_NO_SENSE
1384  */
1385 sense_reason_t
1386 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1387 {
1388         struct se_device *dev = cmd->se_dev;
1389
1390         if (cmd->unknown_data_length) {
1391                 cmd->data_length = size;
1392         } else if (size != cmd->data_length) {
1393                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1394                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1395                         " 0x%02x\n", cmd->se_tfo->fabric_name,
1396                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1397                 /*
1398                  * For READ command for the overflow case keep the existing
1399                  * fabric provided ->data_length. Otherwise for the underflow
1400                  * case, reset ->data_length to the smaller SCSI expected data
1401                  * transfer length.
1402                  */
1403                 if (size > cmd->data_length) {
1404                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1405                         cmd->residual_count = (size - cmd->data_length);
1406                 } else {
1407                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1408                         cmd->residual_count = (cmd->data_length - size);
1409                         /*
1410                          * Do not truncate ->data_length for WRITE command to
1411                          * dump all payload
1412                          */
1413                         if (cmd->data_direction == DMA_FROM_DEVICE) {
1414                                 cmd->data_length = size;
1415                         }
1416                 }
1417
1418                 if (cmd->data_direction == DMA_TO_DEVICE) {
1419                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1420                                 pr_err_ratelimited("Rejecting underflow/overflow"
1421                                                    " for WRITE data CDB\n");
1422                                 return TCM_INVALID_FIELD_IN_COMMAND_IU;
1423                         }
1424                         /*
1425                          * Some fabric drivers like iscsi-target still expect to
1426                          * always reject overflow writes.  Reject this case until
1427                          * full fabric driver level support for overflow writes
1428                          * is introduced tree-wide.
1429                          */
1430                         if (size > cmd->data_length) {
1431                                 pr_err_ratelimited("Rejecting overflow for"
1432                                                    " WRITE control CDB\n");
1433                                 return TCM_INVALID_CDB_FIELD;
1434                         }
1435                 }
1436         }
1437
1438         return target_check_max_data_sg_nents(cmd, dev, size);
1439
1440 }
1441
1442 /*
1443  * Used by fabric modules containing a local struct se_cmd within their
1444  * fabric dependent per I/O descriptor.
1445  *
1446  * Preserves the value of @cmd->tag.
1447  */
1448 void __target_init_cmd(struct se_cmd *cmd,
1449                        const struct target_core_fabric_ops *tfo,
1450                        struct se_session *se_sess, u32 data_length,
1451                        int data_direction, int task_attr,
1452                        unsigned char *sense_buffer, u64 unpacked_lun,
1453                        struct target_cmd_counter *cmd_cnt)
1454 {
1455         INIT_LIST_HEAD(&cmd->se_delayed_node);
1456         INIT_LIST_HEAD(&cmd->se_qf_node);
1457         INIT_LIST_HEAD(&cmd->state_list);
1458         init_completion(&cmd->t_transport_stop_comp);
1459         cmd->free_compl = NULL;
1460         cmd->abrt_compl = NULL;
1461         spin_lock_init(&cmd->t_state_lock);
1462         INIT_WORK(&cmd->work, NULL);
1463         kref_init(&cmd->cmd_kref);
1464
1465         cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1466         cmd->se_tfo = tfo;
1467         cmd->se_sess = se_sess;
1468         cmd->data_length = data_length;
1469         cmd->data_direction = data_direction;
1470         cmd->sam_task_attr = task_attr;
1471         cmd->sense_buffer = sense_buffer;
1472         cmd->orig_fe_lun = unpacked_lun;
1473         cmd->cmd_cnt = cmd_cnt;
1474
1475         if (!(cmd->se_cmd_flags & SCF_USE_CPUID))
1476                 cmd->cpuid = raw_smp_processor_id();
1477
1478         cmd->state_active = false;
1479 }
1480 EXPORT_SYMBOL(__target_init_cmd);
1481
1482 static sense_reason_t
1483 transport_check_alloc_task_attr(struct se_cmd *cmd)
1484 {
1485         struct se_device *dev = cmd->se_dev;
1486
1487         /*
1488          * Check if SAM Task Attribute emulation is enabled for this
1489          * struct se_device storage object
1490          */
1491         if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1492                 return 0;
1493
1494         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1495                 pr_debug("SAM Task Attribute ACA"
1496                         " emulation is not supported\n");
1497                 return TCM_INVALID_CDB_FIELD;
1498         }
1499
1500         return 0;
1501 }
1502
1503 sense_reason_t
1504 target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb, gfp_t gfp)
1505 {
1506         sense_reason_t ret;
1507
1508         /*
1509          * Ensure that the received CDB is less than the max (252 + 8) bytes
1510          * for VARIABLE_LENGTH_CMD
1511          */
1512         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1513                 pr_err("Received SCSI CDB with command_size: %d that"
1514                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1515                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1516                 ret = TCM_INVALID_CDB_FIELD;
1517                 goto err;
1518         }
1519         /*
1520          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1521          * allocate the additional extended CDB buffer now..  Otherwise
1522          * setup the pointer from __t_task_cdb to t_task_cdb.
1523          */
1524         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1525                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb), gfp);
1526                 if (!cmd->t_task_cdb) {
1527                         pr_err("Unable to allocate cmd->t_task_cdb"
1528                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1529                                 scsi_command_size(cdb),
1530                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1531                         ret = TCM_OUT_OF_RESOURCES;
1532                         goto err;
1533                 }
1534         }
1535         /*
1536          * Copy the original CDB into cmd->
1537          */
1538         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1539
1540         trace_target_sequencer_start(cmd);
1541         return 0;
1542
1543 err:
1544         /*
1545          * Copy the CDB here to allow trace_target_cmd_complete() to
1546          * print the cdb to the trace buffers.
1547          */
1548         memcpy(cmd->t_task_cdb, cdb, min(scsi_command_size(cdb),
1549                                          (unsigned int)TCM_MAX_COMMAND_SIZE));
1550         return ret;
1551 }
1552 EXPORT_SYMBOL(target_cmd_init_cdb);
1553
1554 sense_reason_t
1555 target_cmd_parse_cdb(struct se_cmd *cmd)
1556 {
1557         struct se_device *dev = cmd->se_dev;
1558         sense_reason_t ret;
1559
1560         ret = dev->transport->parse_cdb(cmd);
1561         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1562                 pr_debug_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1563                                      cmd->se_tfo->fabric_name,
1564                                      cmd->se_sess->se_node_acl->initiatorname,
1565                                      cmd->t_task_cdb[0]);
1566         if (ret)
1567                 return ret;
1568
1569         ret = transport_check_alloc_task_attr(cmd);
1570         if (ret)
1571                 return ret;
1572
1573         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1574         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1575         return 0;
1576 }
1577 EXPORT_SYMBOL(target_cmd_parse_cdb);
1578
1579 static int __target_submit(struct se_cmd *cmd)
1580 {
1581         sense_reason_t ret;
1582
1583         might_sleep();
1584
1585         /*
1586          * Check if we need to delay processing because of ALUA
1587          * Active/NonOptimized primary access state..
1588          */
1589         core_alua_check_nonop_delay(cmd);
1590
1591         if (cmd->t_data_nents != 0) {
1592                 /*
1593                  * This is primarily a hack for udev and tcm loop which sends
1594                  * INQUIRYs with a single page and expects the data to be
1595                  * cleared.
1596                  */
1597                 if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1598                     cmd->data_direction == DMA_FROM_DEVICE) {
1599                         struct scatterlist *sgl = cmd->t_data_sg;
1600                         unsigned char *buf = NULL;
1601
1602                         BUG_ON(!sgl);
1603
1604                         buf = kmap_local_page(sg_page(sgl));
1605                         if (buf) {
1606                                 memset(buf + sgl->offset, 0, sgl->length);
1607                                 kunmap_local(buf);
1608                         }
1609                 }
1610         }
1611
1612         if (!cmd->se_lun) {
1613                 dump_stack();
1614                 pr_err("cmd->se_lun is NULL\n");
1615                 return -EINVAL;
1616         }
1617
1618         /*
1619          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1620          * outstanding descriptors are handled correctly during shutdown via
1621          * transport_wait_for_tasks()
1622          *
1623          * Also, we don't take cmd->t_state_lock here as we only expect
1624          * this to be called for initial descriptor submission.
1625          */
1626         cmd->t_state = TRANSPORT_NEW_CMD;
1627         cmd->transport_state |= CMD_T_ACTIVE;
1628
1629         /*
1630          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1631          * so follow TRANSPORT_NEW_CMD processing thread context usage
1632          * and call transport_generic_request_failure() if necessary..
1633          */
1634         ret = transport_generic_new_cmd(cmd);
1635         if (ret)
1636                 transport_generic_request_failure(cmd, ret);
1637         return 0;
1638 }
1639
1640 sense_reason_t
1641 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1642                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1643 {
1644         if (!sgl || !sgl_count)
1645                 return 0;
1646
1647         /*
1648          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1649          * scatterlists already have been set to follow what the fabric
1650          * passes for the original expected data transfer length.
1651          */
1652         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1653                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1654                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1655                 return TCM_INVALID_CDB_FIELD;
1656         }
1657
1658         cmd->t_data_sg = sgl;
1659         cmd->t_data_nents = sgl_count;
1660         cmd->t_bidi_data_sg = sgl_bidi;
1661         cmd->t_bidi_data_nents = sgl_bidi_count;
1662
1663         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1664         return 0;
1665 }
1666
1667 /**
1668  * target_init_cmd - initialize se_cmd
1669  * @se_cmd: command descriptor to init
1670  * @se_sess: associated se_sess for endpoint
1671  * @sense: pointer to SCSI sense buffer
1672  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1673  * @data_length: fabric expected data transfer length
1674  * @task_attr: SAM task attribute
1675  * @data_dir: DMA data direction
1676  * @flags: flags for command submission from target_sc_flags_tables
1677  *
1678  * Task tags are supported if the caller has set @se_cmd->tag.
1679  *
1680  * Returns:
1681  *      - less than zero to signal active I/O shutdown failure.
1682  *      - zero on success.
1683  *
1684  * If the fabric driver calls target_stop_session, then it must check the
1685  * return code and handle failures. This will never fail for other drivers,
1686  * and the return code can be ignored.
1687  */
1688 int target_init_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1689                     unsigned char *sense, u64 unpacked_lun,
1690                     u32 data_length, int task_attr, int data_dir, int flags)
1691 {
1692         struct se_portal_group *se_tpg;
1693
1694         se_tpg = se_sess->se_tpg;
1695         BUG_ON(!se_tpg);
1696         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1697
1698         if (flags & TARGET_SCF_USE_CPUID)
1699                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1700         /*
1701          * Signal bidirectional data payloads to target-core
1702          */
1703         if (flags & TARGET_SCF_BIDI_OP)
1704                 se_cmd->se_cmd_flags |= SCF_BIDI;
1705
1706         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1707                 se_cmd->unknown_data_length = 1;
1708         /*
1709          * Initialize se_cmd for target operation.  From this point
1710          * exceptions are handled by sending exception status via
1711          * target_core_fabric_ops->queue_status() callback
1712          */
1713         __target_init_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, data_length,
1714                           data_dir, task_attr, sense, unpacked_lun,
1715                           se_sess->cmd_cnt);
1716
1717         /*
1718          * Obtain struct se_cmd->cmd_kref reference. A second kref_get here is
1719          * necessary for fabrics using TARGET_SCF_ACK_KREF that expect a second
1720          * kref_put() to happen during fabric packet acknowledgement.
1721          */
1722         return target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1723 }
1724 EXPORT_SYMBOL_GPL(target_init_cmd);
1725
1726 /**
1727  * target_submit_prep - prepare cmd for submission
1728  * @se_cmd: command descriptor to prep
1729  * @cdb: pointer to SCSI CDB
1730  * @sgl: struct scatterlist memory for unidirectional mapping
1731  * @sgl_count: scatterlist count for unidirectional mapping
1732  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1733  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1734  * @sgl_prot: struct scatterlist memory protection information
1735  * @sgl_prot_count: scatterlist count for protection information
1736  * @gfp: gfp allocation type
1737  *
1738  * Returns:
1739  *      - less than zero to signal failure.
1740  *      - zero on success.
1741  *
1742  * If failure is returned, lio will the callers queue_status to complete
1743  * the cmd.
1744  */
1745 int target_submit_prep(struct se_cmd *se_cmd, unsigned char *cdb,
1746                        struct scatterlist *sgl, u32 sgl_count,
1747                        struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1748                        struct scatterlist *sgl_prot, u32 sgl_prot_count,
1749                        gfp_t gfp)
1750 {
1751         sense_reason_t rc;
1752
1753         rc = target_cmd_init_cdb(se_cmd, cdb, gfp);
1754         if (rc)
1755                 goto send_cc_direct;
1756
1757         /*
1758          * Locate se_lun pointer and attach it to struct se_cmd
1759          */
1760         rc = transport_lookup_cmd_lun(se_cmd);
1761         if (rc)
1762                 goto send_cc_direct;
1763
1764         rc = target_cmd_parse_cdb(se_cmd);
1765         if (rc != 0)
1766                 goto generic_fail;
1767
1768         /*
1769          * Save pointers for SGLs containing protection information,
1770          * if present.
1771          */
1772         if (sgl_prot_count) {
1773                 se_cmd->t_prot_sg = sgl_prot;
1774                 se_cmd->t_prot_nents = sgl_prot_count;
1775                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1776         }
1777
1778         /*
1779          * When a non zero sgl_count has been passed perform SGL passthrough
1780          * mapping for pre-allocated fabric memory instead of having target
1781          * core perform an internal SGL allocation..
1782          */
1783         if (sgl_count != 0) {
1784                 BUG_ON(!sgl);
1785
1786                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1787                                 sgl_bidi, sgl_bidi_count);
1788                 if (rc != 0)
1789                         goto generic_fail;
1790         }
1791
1792         return 0;
1793
1794 send_cc_direct:
1795         transport_send_check_condition_and_sense(se_cmd, rc, 0);
1796         target_put_sess_cmd(se_cmd);
1797         return -EIO;
1798
1799 generic_fail:
1800         transport_generic_request_failure(se_cmd, rc);
1801         return -EIO;
1802 }
1803 EXPORT_SYMBOL_GPL(target_submit_prep);
1804
1805 /**
1806  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1807  *
1808  * @se_cmd: command descriptor to submit
1809  * @se_sess: associated se_sess for endpoint
1810  * @cdb: pointer to SCSI CDB
1811  * @sense: pointer to SCSI sense buffer
1812  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1813  * @data_length: fabric expected data transfer length
1814  * @task_attr: SAM task attribute
1815  * @data_dir: DMA data direction
1816  * @flags: flags for command submission from target_sc_flags_tables
1817  *
1818  * Task tags are supported if the caller has set @se_cmd->tag.
1819  *
1820  * This may only be called from process context, and also currently
1821  * assumes internal allocation of fabric payload buffer by target-core.
1822  *
1823  * It also assumes interal target core SGL memory allocation.
1824  *
1825  * This function must only be used by drivers that do their own
1826  * sync during shutdown and does not use target_stop_session. If there
1827  * is a failure this function will call into the fabric driver's
1828  * queue_status with a CHECK_CONDITION.
1829  */
1830 void target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1831                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1832                 u32 data_length, int task_attr, int data_dir, int flags)
1833 {
1834         int rc;
1835
1836         rc = target_init_cmd(se_cmd, se_sess, sense, unpacked_lun, data_length,
1837                              task_attr, data_dir, flags);
1838         WARN(rc, "Invalid target_submit_cmd use. Driver must not use target_stop_session or call target_init_cmd directly.\n");
1839         if (rc)
1840                 return;
1841
1842         if (target_submit_prep(se_cmd, cdb, NULL, 0, NULL, 0, NULL, 0,
1843                                GFP_KERNEL))
1844                 return;
1845
1846         target_submit(se_cmd);
1847 }
1848 EXPORT_SYMBOL(target_submit_cmd);
1849
1850
1851 static struct se_dev_plug *target_plug_device(struct se_device *se_dev)
1852 {
1853         struct se_dev_plug *se_plug;
1854
1855         if (!se_dev->transport->plug_device)
1856                 return NULL;
1857
1858         se_plug = se_dev->transport->plug_device(se_dev);
1859         if (!se_plug)
1860                 return NULL;
1861
1862         se_plug->se_dev = se_dev;
1863         /*
1864          * We have a ref to the lun at this point, but the cmds could
1865          * complete before we unplug, so grab a ref to the se_device so we
1866          * can call back into the backend.
1867          */
1868         config_group_get(&se_dev->dev_group);
1869         return se_plug;
1870 }
1871
1872 static void target_unplug_device(struct se_dev_plug *se_plug)
1873 {
1874         struct se_device *se_dev = se_plug->se_dev;
1875
1876         se_dev->transport->unplug_device(se_plug);
1877         config_group_put(&se_dev->dev_group);
1878 }
1879
1880 void target_queued_submit_work(struct work_struct *work)
1881 {
1882         struct se_cmd_queue *sq = container_of(work, struct se_cmd_queue, work);
1883         struct se_cmd *se_cmd, *next_cmd;
1884         struct se_dev_plug *se_plug = NULL;
1885         struct se_device *se_dev = NULL;
1886         struct llist_node *cmd_list;
1887
1888         cmd_list = llist_del_all(&sq->cmd_list);
1889         if (!cmd_list)
1890                 /* Previous call took what we were queued to submit */
1891                 return;
1892
1893         cmd_list = llist_reverse_order(cmd_list);
1894         llist_for_each_entry_safe(se_cmd, next_cmd, cmd_list, se_cmd_list) {
1895                 if (!se_dev) {
1896                         se_dev = se_cmd->se_dev;
1897                         se_plug = target_plug_device(se_dev);
1898                 }
1899
1900                 __target_submit(se_cmd);
1901         }
1902
1903         if (se_plug)
1904                 target_unplug_device(se_plug);
1905 }
1906
1907 /**
1908  * target_queue_submission - queue the cmd to run on the LIO workqueue
1909  * @se_cmd: command descriptor to submit
1910  */
1911 static void target_queue_submission(struct se_cmd *se_cmd)
1912 {
1913         struct se_device *se_dev = se_cmd->se_dev;
1914         int cpu = se_cmd->cpuid;
1915         struct se_cmd_queue *sq;
1916
1917         sq = &se_dev->queues[cpu].sq;
1918         llist_add(&se_cmd->se_cmd_list, &sq->cmd_list);
1919         queue_work_on(cpu, target_submission_wq, &sq->work);
1920 }
1921
1922 /**
1923  * target_submit - perform final initialization and submit cmd to LIO core
1924  * @cmd: command descriptor to submit
1925  *
1926  * target_submit_prep or something similar must have been called on the cmd,
1927  * and this must be called from process context.
1928  */
1929 int target_submit(struct se_cmd *se_cmd)
1930 {
1931         const struct target_core_fabric_ops *tfo = se_cmd->se_sess->se_tpg->se_tpg_tfo;
1932         struct se_dev_attrib *da = &se_cmd->se_dev->dev_attrib;
1933         u8 submit_type;
1934
1935         if (da->submit_type == TARGET_FABRIC_DEFAULT_SUBMIT)
1936                 submit_type = tfo->default_submit_type;
1937         else if (da->submit_type == TARGET_DIRECT_SUBMIT &&
1938                  tfo->direct_submit_supp)
1939                 submit_type = TARGET_DIRECT_SUBMIT;
1940         else
1941                 submit_type = TARGET_QUEUE_SUBMIT;
1942
1943         if (submit_type == TARGET_DIRECT_SUBMIT)
1944                 return __target_submit(se_cmd);
1945
1946         target_queue_submission(se_cmd);
1947         return 0;
1948 }
1949 EXPORT_SYMBOL_GPL(target_submit);
1950
1951 static void target_complete_tmr_failure(struct work_struct *work)
1952 {
1953         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1954
1955         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1956         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1957
1958         transport_lun_remove_cmd(se_cmd);
1959         transport_cmd_check_stop_to_fabric(se_cmd);
1960 }
1961
1962 /**
1963  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1964  *                     for TMR CDBs
1965  *
1966  * @se_cmd: command descriptor to submit
1967  * @se_sess: associated se_sess for endpoint
1968  * @sense: pointer to SCSI sense buffer
1969  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1970  * @fabric_tmr_ptr: fabric context for TMR req
1971  * @tm_type: Type of TM request
1972  * @gfp: gfp type for caller
1973  * @tag: referenced task tag for TMR_ABORT_TASK
1974  * @flags: submit cmd flags
1975  *
1976  * Callable from all contexts.
1977  **/
1978
1979 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1980                 unsigned char *sense, u64 unpacked_lun,
1981                 void *fabric_tmr_ptr, unsigned char tm_type,
1982                 gfp_t gfp, u64 tag, int flags)
1983 {
1984         struct se_portal_group *se_tpg;
1985         int ret;
1986
1987         se_tpg = se_sess->se_tpg;
1988         BUG_ON(!se_tpg);
1989
1990         __target_init_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1991                           0, DMA_NONE, TCM_SIMPLE_TAG, sense, unpacked_lun,
1992                           se_sess->cmd_cnt);
1993         /*
1994          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1995          * allocation failure.
1996          */
1997         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1998         if (ret < 0)
1999                 return -ENOMEM;
2000
2001         if (tm_type == TMR_ABORT_TASK)
2002                 se_cmd->se_tmr_req->ref_task_tag = tag;
2003
2004         /* See target_submit_cmd for commentary */
2005         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
2006         if (ret) {
2007                 core_tmr_release_req(se_cmd->se_tmr_req);
2008                 return ret;
2009         }
2010
2011         ret = transport_lookup_tmr_lun(se_cmd);
2012         if (ret)
2013                 goto failure;
2014
2015         transport_generic_handle_tmr(se_cmd);
2016         return 0;
2017
2018         /*
2019          * For callback during failure handling, push this work off
2020          * to process context with TMR_LUN_DOES_NOT_EXIST status.
2021          */
2022 failure:
2023         INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
2024         schedule_work(&se_cmd->work);
2025         return 0;
2026 }
2027 EXPORT_SYMBOL(target_submit_tmr);
2028
2029 /*
2030  * Handle SAM-esque emulation for generic transport request failures.
2031  */
2032 void transport_generic_request_failure(struct se_cmd *cmd,
2033                 sense_reason_t sense_reason)
2034 {
2035         int ret = 0, post_ret;
2036
2037         pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
2038                  sense_reason);
2039         target_show_cmd("-----[ ", cmd);
2040
2041         /*
2042          * For SAM Task Attribute emulation for failed struct se_cmd
2043          */
2044         transport_complete_task_attr(cmd);
2045
2046         if (cmd->transport_complete_callback)
2047                 cmd->transport_complete_callback(cmd, false, &post_ret);
2048
2049         if (cmd->transport_state & CMD_T_ABORTED) {
2050                 INIT_WORK(&cmd->work, target_abort_work);
2051                 queue_work(target_completion_wq, &cmd->work);
2052                 return;
2053         }
2054
2055         switch (sense_reason) {
2056         case TCM_NON_EXISTENT_LUN:
2057         case TCM_UNSUPPORTED_SCSI_OPCODE:
2058         case TCM_INVALID_CDB_FIELD:
2059         case TCM_INVALID_PARAMETER_LIST:
2060         case TCM_PARAMETER_LIST_LENGTH_ERROR:
2061         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2062         case TCM_UNKNOWN_MODE_PAGE:
2063         case TCM_WRITE_PROTECTED:
2064         case TCM_ADDRESS_OUT_OF_RANGE:
2065         case TCM_CHECK_CONDITION_ABORT_CMD:
2066         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2067         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2068         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2069         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2070         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
2071         case TCM_TOO_MANY_TARGET_DESCS:
2072         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
2073         case TCM_TOO_MANY_SEGMENT_DESCS:
2074         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
2075         case TCM_INVALID_FIELD_IN_COMMAND_IU:
2076         case TCM_ALUA_TG_PT_STANDBY:
2077         case TCM_ALUA_TG_PT_UNAVAILABLE:
2078         case TCM_ALUA_STATE_TRANSITION:
2079         case TCM_ALUA_OFFLINE:
2080                 break;
2081         case TCM_OUT_OF_RESOURCES:
2082                 cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
2083                 goto queue_status;
2084         case TCM_LUN_BUSY:
2085                 cmd->scsi_status = SAM_STAT_BUSY;
2086                 goto queue_status;
2087         case TCM_RESERVATION_CONFLICT:
2088                 /*
2089                  * No SENSE Data payload for this case, set SCSI Status
2090                  * and queue the response to $FABRIC_MOD.
2091                  *
2092                  * Uses linux/include/scsi/scsi.h SAM status codes defs
2093                  */
2094                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
2095                 /*
2096                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
2097                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
2098                  * CONFLICT STATUS.
2099                  *
2100                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
2101                  */
2102                 if (cmd->se_sess &&
2103                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl
2104                                         == TARGET_UA_INTLCK_CTRL_ESTABLISH_UA) {
2105                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
2106                                                cmd->orig_fe_lun, 0x2C,
2107                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
2108                 }
2109
2110                 goto queue_status;
2111         default:
2112                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
2113                         cmd->t_task_cdb[0], sense_reason);
2114                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
2115                 break;
2116         }
2117
2118         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
2119         if (ret)
2120                 goto queue_full;
2121
2122 check_stop:
2123         transport_lun_remove_cmd(cmd);
2124         transport_cmd_check_stop_to_fabric(cmd);
2125         return;
2126
2127 queue_status:
2128         trace_target_cmd_complete(cmd);
2129         ret = cmd->se_tfo->queue_status(cmd);
2130         if (!ret)
2131                 goto check_stop;
2132 queue_full:
2133         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2134 }
2135 EXPORT_SYMBOL(transport_generic_request_failure);
2136
2137 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
2138 {
2139         sense_reason_t ret;
2140
2141         if (!cmd->execute_cmd) {
2142                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2143                 goto err;
2144         }
2145         if (do_checks) {
2146                 /*
2147                  * Check for an existing UNIT ATTENTION condition after
2148                  * target_handle_task_attr() has done SAM task attr
2149                  * checking, and possibly have already defered execution
2150                  * out to target_restart_delayed_cmds() context.
2151                  */
2152                 ret = target_scsi3_ua_check(cmd);
2153                 if (ret)
2154                         goto err;
2155
2156                 ret = target_alua_state_check(cmd);
2157                 if (ret)
2158                         goto err;
2159
2160                 ret = target_check_reservation(cmd);
2161                 if (ret) {
2162                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
2163                         goto err;
2164                 }
2165         }
2166
2167         ret = cmd->execute_cmd(cmd);
2168         if (!ret)
2169                 return;
2170 err:
2171         spin_lock_irq(&cmd->t_state_lock);
2172         cmd->transport_state &= ~CMD_T_SENT;
2173         spin_unlock_irq(&cmd->t_state_lock);
2174
2175         transport_generic_request_failure(cmd, ret);
2176 }
2177
2178 static int target_write_prot_action(struct se_cmd *cmd)
2179 {
2180         u32 sectors;
2181         /*
2182          * Perform WRITE_INSERT of PI using software emulation when backend
2183          * device has PI enabled, if the transport has not already generated
2184          * PI using hardware WRITE_INSERT offload.
2185          */
2186         switch (cmd->prot_op) {
2187         case TARGET_PROT_DOUT_INSERT:
2188                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
2189                         sbc_dif_generate(cmd);
2190                 break;
2191         case TARGET_PROT_DOUT_STRIP:
2192                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
2193                         break;
2194
2195                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
2196                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2197                                              sectors, 0, cmd->t_prot_sg, 0);
2198                 if (unlikely(cmd->pi_err)) {
2199                         spin_lock_irq(&cmd->t_state_lock);
2200                         cmd->transport_state &= ~CMD_T_SENT;
2201                         spin_unlock_irq(&cmd->t_state_lock);
2202                         transport_generic_request_failure(cmd, cmd->pi_err);
2203                         return -1;
2204                 }
2205                 break;
2206         default:
2207                 break;
2208         }
2209
2210         return 0;
2211 }
2212
2213 static bool target_handle_task_attr(struct se_cmd *cmd)
2214 {
2215         struct se_device *dev = cmd->se_dev;
2216
2217         if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2218                 return false;
2219
2220         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
2221
2222         /*
2223          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
2224          * to allow the passed struct se_cmd list of tasks to the front of the list.
2225          */
2226         switch (cmd->sam_task_attr) {
2227         case TCM_HEAD_TAG:
2228                 atomic_inc_mb(&dev->non_ordered);
2229                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
2230                          cmd->t_task_cdb[0]);
2231                 return false;
2232         case TCM_ORDERED_TAG:
2233                 atomic_inc_mb(&dev->delayed_cmd_count);
2234
2235                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
2236                          cmd->t_task_cdb[0]);
2237                 break;
2238         default:
2239                 /*
2240                  * For SIMPLE and UNTAGGED Task Attribute commands
2241                  */
2242                 atomic_inc_mb(&dev->non_ordered);
2243
2244                 if (atomic_read(&dev->delayed_cmd_count) == 0)
2245                         return false;
2246                 break;
2247         }
2248
2249         if (cmd->sam_task_attr != TCM_ORDERED_TAG) {
2250                 atomic_inc_mb(&dev->delayed_cmd_count);
2251                 /*
2252                  * We will account for this when we dequeue from the delayed
2253                  * list.
2254                  */
2255                 atomic_dec_mb(&dev->non_ordered);
2256         }
2257
2258         spin_lock_irq(&cmd->t_state_lock);
2259         cmd->transport_state &= ~CMD_T_SENT;
2260         spin_unlock_irq(&cmd->t_state_lock);
2261
2262         spin_lock(&dev->delayed_cmd_lock);
2263         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
2264         spin_unlock(&dev->delayed_cmd_lock);
2265
2266         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
2267                 cmd->t_task_cdb[0], cmd->sam_task_attr);
2268         /*
2269          * We may have no non ordered cmds when this function started or we
2270          * could have raced with the last simple/head cmd completing, so kick
2271          * the delayed handler here.
2272          */
2273         schedule_work(&dev->delayed_cmd_work);
2274         return true;
2275 }
2276
2277 void target_execute_cmd(struct se_cmd *cmd)
2278 {
2279         /*
2280          * Determine if frontend context caller is requesting the stopping of
2281          * this command for frontend exceptions.
2282          *
2283          * If the received CDB has already been aborted stop processing it here.
2284          */
2285         if (target_cmd_interrupted(cmd))
2286                 return;
2287
2288         spin_lock_irq(&cmd->t_state_lock);
2289         cmd->t_state = TRANSPORT_PROCESSING;
2290         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
2291         spin_unlock_irq(&cmd->t_state_lock);
2292
2293         if (target_write_prot_action(cmd))
2294                 return;
2295
2296         if (target_handle_task_attr(cmd))
2297                 return;
2298
2299         __target_execute_cmd(cmd, true);
2300 }
2301 EXPORT_SYMBOL(target_execute_cmd);
2302
2303 /*
2304  * Process all commands up to the last received ORDERED task attribute which
2305  * requires another blocking boundary
2306  */
2307 void target_do_delayed_work(struct work_struct *work)
2308 {
2309         struct se_device *dev = container_of(work, struct se_device,
2310                                              delayed_cmd_work);
2311
2312         spin_lock(&dev->delayed_cmd_lock);
2313         while (!dev->ordered_sync_in_progress) {
2314                 struct se_cmd *cmd;
2315
2316                 if (list_empty(&dev->delayed_cmd_list))
2317                         break;
2318
2319                 cmd = list_entry(dev->delayed_cmd_list.next,
2320                                  struct se_cmd, se_delayed_node);
2321
2322                 if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2323                         /*
2324                          * Check if we started with:
2325                          * [ordered] [simple] [ordered]
2326                          * and we are now at the last ordered so we have to wait
2327                          * for the simple cmd.
2328                          */
2329                         if (atomic_read(&dev->non_ordered) > 0)
2330                                 break;
2331
2332                         dev->ordered_sync_in_progress = true;
2333                 }
2334
2335                 list_del(&cmd->se_delayed_node);
2336                 atomic_dec_mb(&dev->delayed_cmd_count);
2337                 spin_unlock(&dev->delayed_cmd_lock);
2338
2339                 if (cmd->sam_task_attr != TCM_ORDERED_TAG)
2340                         atomic_inc_mb(&dev->non_ordered);
2341
2342                 cmd->transport_state |= CMD_T_SENT;
2343
2344                 __target_execute_cmd(cmd, true);
2345
2346                 spin_lock(&dev->delayed_cmd_lock);
2347         }
2348         spin_unlock(&dev->delayed_cmd_lock);
2349 }
2350
2351 /*
2352  * Called from I/O completion to determine which dormant/delayed
2353  * and ordered cmds need to have their tasks added to the execution queue.
2354  */
2355 static void transport_complete_task_attr(struct se_cmd *cmd)
2356 {
2357         struct se_device *dev = cmd->se_dev;
2358
2359         if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2360                 return;
2361
2362         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2363                 goto restart;
2364
2365         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2366                 atomic_dec_mb(&dev->non_ordered);
2367                 dev->dev_cur_ordered_id++;
2368         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2369                 atomic_dec_mb(&dev->non_ordered);
2370                 dev->dev_cur_ordered_id++;
2371                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2372                          dev->dev_cur_ordered_id);
2373         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2374                 spin_lock(&dev->delayed_cmd_lock);
2375                 dev->ordered_sync_in_progress = false;
2376                 spin_unlock(&dev->delayed_cmd_lock);
2377
2378                 dev->dev_cur_ordered_id++;
2379                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2380                          dev->dev_cur_ordered_id);
2381         }
2382         cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2383
2384 restart:
2385         if (atomic_read(&dev->delayed_cmd_count) > 0)
2386                 schedule_work(&dev->delayed_cmd_work);
2387 }
2388
2389 static void transport_complete_qf(struct se_cmd *cmd)
2390 {
2391         int ret = 0;
2392
2393         transport_complete_task_attr(cmd);
2394         /*
2395          * If a fabric driver ->write_pending() or ->queue_data_in() callback
2396          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2397          * the same callbacks should not be retried.  Return CHECK_CONDITION
2398          * if a scsi_status is not already set.
2399          *
2400          * If a fabric driver ->queue_status() has returned non zero, always
2401          * keep retrying no matter what..
2402          */
2403         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2404                 if (cmd->scsi_status)
2405                         goto queue_status;
2406
2407                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2408                 goto queue_status;
2409         }
2410
2411         /*
2412          * Check if we need to send a sense buffer from
2413          * the struct se_cmd in question. We do NOT want
2414          * to take this path of the IO has been marked as
2415          * needing to be treated like a "normal read". This
2416          * is the case if it's a tape read, and either the
2417          * FM, EOM, or ILI bits are set, but there is no
2418          * sense data.
2419          */
2420         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2421             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2422                 goto queue_status;
2423
2424         switch (cmd->data_direction) {
2425         case DMA_FROM_DEVICE:
2426                 /* queue status if not treating this as a normal read */
2427                 if (cmd->scsi_status &&
2428                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2429                         goto queue_status;
2430
2431                 trace_target_cmd_complete(cmd);
2432                 ret = cmd->se_tfo->queue_data_in(cmd);
2433                 break;
2434         case DMA_TO_DEVICE:
2435                 if (cmd->se_cmd_flags & SCF_BIDI) {
2436                         ret = cmd->se_tfo->queue_data_in(cmd);
2437                         break;
2438                 }
2439                 fallthrough;
2440         case DMA_NONE:
2441 queue_status:
2442                 trace_target_cmd_complete(cmd);
2443                 ret = cmd->se_tfo->queue_status(cmd);
2444                 break;
2445         default:
2446                 break;
2447         }
2448
2449         if (ret < 0) {
2450                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2451                 return;
2452         }
2453         transport_lun_remove_cmd(cmd);
2454         transport_cmd_check_stop_to_fabric(cmd);
2455 }
2456
2457 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2458                                         int err, bool write_pending)
2459 {
2460         /*
2461          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2462          * ->queue_data_in() callbacks from new process context.
2463          *
2464          * Otherwise for other errors, transport_complete_qf() will send
2465          * CHECK_CONDITION via ->queue_status() instead of attempting to
2466          * retry associated fabric driver data-transfer callbacks.
2467          */
2468         if (err == -EAGAIN || err == -ENOMEM) {
2469                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2470                                                  TRANSPORT_COMPLETE_QF_OK;
2471         } else {
2472                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2473                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2474         }
2475
2476         spin_lock_irq(&dev->qf_cmd_lock);
2477         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2478         atomic_inc_mb(&dev->dev_qf_count);
2479         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2480
2481         schedule_work(&cmd->se_dev->qf_work_queue);
2482 }
2483
2484 static bool target_read_prot_action(struct se_cmd *cmd)
2485 {
2486         switch (cmd->prot_op) {
2487         case TARGET_PROT_DIN_STRIP:
2488                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2489                         u32 sectors = cmd->data_length >>
2490                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2491
2492                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2493                                                      sectors, 0, cmd->t_prot_sg,
2494                                                      0);
2495                         if (cmd->pi_err)
2496                                 return true;
2497                 }
2498                 break;
2499         case TARGET_PROT_DIN_INSERT:
2500                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2501                         break;
2502
2503                 sbc_dif_generate(cmd);
2504                 break;
2505         default:
2506                 break;
2507         }
2508
2509         return false;
2510 }
2511
2512 static void target_complete_ok_work(struct work_struct *work)
2513 {
2514         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2515         int ret;
2516
2517         /*
2518          * Check if we need to move delayed/dormant tasks from cmds on the
2519          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2520          * Attribute.
2521          */
2522         transport_complete_task_attr(cmd);
2523
2524         /*
2525          * Check to schedule QUEUE_FULL work, or execute an existing
2526          * cmd->transport_qf_callback()
2527          */
2528         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2529                 schedule_work(&cmd->se_dev->qf_work_queue);
2530
2531         /*
2532          * Check if we need to send a sense buffer from
2533          * the struct se_cmd in question. We do NOT want
2534          * to take this path of the IO has been marked as
2535          * needing to be treated like a "normal read". This
2536          * is the case if it's a tape read, and either the
2537          * FM, EOM, or ILI bits are set, but there is no
2538          * sense data.
2539          */
2540         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2541             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2542                 WARN_ON(!cmd->scsi_status);
2543                 ret = transport_send_check_condition_and_sense(
2544                                         cmd, 0, 1);
2545                 if (ret)
2546                         goto queue_full;
2547
2548                 transport_lun_remove_cmd(cmd);
2549                 transport_cmd_check_stop_to_fabric(cmd);
2550                 return;
2551         }
2552         /*
2553          * Check for a callback, used by amongst other things
2554          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2555          */
2556         if (cmd->transport_complete_callback) {
2557                 sense_reason_t rc;
2558                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2559                 bool zero_dl = !(cmd->data_length);
2560                 int post_ret = 0;
2561
2562                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2563                 if (!rc && !post_ret) {
2564                         if (caw && zero_dl)
2565                                 goto queue_rsp;
2566
2567                         return;
2568                 } else if (rc) {
2569                         ret = transport_send_check_condition_and_sense(cmd,
2570                                                 rc, 0);
2571                         if (ret)
2572                                 goto queue_full;
2573
2574                         transport_lun_remove_cmd(cmd);
2575                         transport_cmd_check_stop_to_fabric(cmd);
2576                         return;
2577                 }
2578         }
2579
2580 queue_rsp:
2581         switch (cmd->data_direction) {
2582         case DMA_FROM_DEVICE:
2583                 /*
2584                  * if this is a READ-type IO, but SCSI status
2585                  * is set, then skip returning data and just
2586                  * return the status -- unless this IO is marked
2587                  * as needing to be treated as a normal read,
2588                  * in which case we want to go ahead and return
2589                  * the data. This happens, for example, for tape
2590                  * reads with the FM, EOM, or ILI bits set, with
2591                  * no sense data.
2592                  */
2593                 if (cmd->scsi_status &&
2594                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2595                         goto queue_status;
2596
2597                 atomic_long_add(cmd->data_length,
2598                                 &cmd->se_lun->lun_stats.tx_data_octets);
2599                 /*
2600                  * Perform READ_STRIP of PI using software emulation when
2601                  * backend had PI enabled, if the transport will not be
2602                  * performing hardware READ_STRIP offload.
2603                  */
2604                 if (target_read_prot_action(cmd)) {
2605                         ret = transport_send_check_condition_and_sense(cmd,
2606                                                 cmd->pi_err, 0);
2607                         if (ret)
2608                                 goto queue_full;
2609
2610                         transport_lun_remove_cmd(cmd);
2611                         transport_cmd_check_stop_to_fabric(cmd);
2612                         return;
2613                 }
2614
2615                 trace_target_cmd_complete(cmd);
2616                 ret = cmd->se_tfo->queue_data_in(cmd);
2617                 if (ret)
2618                         goto queue_full;
2619                 break;
2620         case DMA_TO_DEVICE:
2621                 atomic_long_add(cmd->data_length,
2622                                 &cmd->se_lun->lun_stats.rx_data_octets);
2623                 /*
2624                  * Check if we need to send READ payload for BIDI-COMMAND
2625                  */
2626                 if (cmd->se_cmd_flags & SCF_BIDI) {
2627                         atomic_long_add(cmd->data_length,
2628                                         &cmd->se_lun->lun_stats.tx_data_octets);
2629                         ret = cmd->se_tfo->queue_data_in(cmd);
2630                         if (ret)
2631                                 goto queue_full;
2632                         break;
2633                 }
2634                 fallthrough;
2635         case DMA_NONE:
2636 queue_status:
2637                 trace_target_cmd_complete(cmd);
2638                 ret = cmd->se_tfo->queue_status(cmd);
2639                 if (ret)
2640                         goto queue_full;
2641                 break;
2642         default:
2643                 break;
2644         }
2645
2646         transport_lun_remove_cmd(cmd);
2647         transport_cmd_check_stop_to_fabric(cmd);
2648         return;
2649
2650 queue_full:
2651         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2652                 " data_direction: %d\n", cmd, cmd->data_direction);
2653
2654         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2655 }
2656
2657 void target_free_sgl(struct scatterlist *sgl, int nents)
2658 {
2659         sgl_free_n_order(sgl, nents, 0);
2660 }
2661 EXPORT_SYMBOL(target_free_sgl);
2662
2663 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2664 {
2665         /*
2666          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2667          * emulation, and free + reset pointers if necessary..
2668          */
2669         if (!cmd->t_data_sg_orig)
2670                 return;
2671
2672         kfree(cmd->t_data_sg);
2673         cmd->t_data_sg = cmd->t_data_sg_orig;
2674         cmd->t_data_sg_orig = NULL;
2675         cmd->t_data_nents = cmd->t_data_nents_orig;
2676         cmd->t_data_nents_orig = 0;
2677 }
2678
2679 static inline void transport_free_pages(struct se_cmd *cmd)
2680 {
2681         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2682                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2683                 cmd->t_prot_sg = NULL;
2684                 cmd->t_prot_nents = 0;
2685         }
2686
2687         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2688                 /*
2689                  * Release special case READ buffer payload required for
2690                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2691                  */
2692                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2693                         target_free_sgl(cmd->t_bidi_data_sg,
2694                                            cmd->t_bidi_data_nents);
2695                         cmd->t_bidi_data_sg = NULL;
2696                         cmd->t_bidi_data_nents = 0;
2697                 }
2698                 transport_reset_sgl_orig(cmd);
2699                 return;
2700         }
2701         transport_reset_sgl_orig(cmd);
2702
2703         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2704         cmd->t_data_sg = NULL;
2705         cmd->t_data_nents = 0;
2706
2707         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2708         cmd->t_bidi_data_sg = NULL;
2709         cmd->t_bidi_data_nents = 0;
2710 }
2711
2712 void *transport_kmap_data_sg(struct se_cmd *cmd)
2713 {
2714         struct scatterlist *sg = cmd->t_data_sg;
2715         struct page **pages;
2716         int i;
2717
2718         /*
2719          * We need to take into account a possible offset here for fabrics like
2720          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2721          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2722          */
2723         if (!cmd->t_data_nents)
2724                 return NULL;
2725
2726         BUG_ON(!sg);
2727         if (cmd->t_data_nents == 1)
2728                 return kmap(sg_page(sg)) + sg->offset;
2729
2730         /* >1 page. use vmap */
2731         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2732         if (!pages)
2733                 return NULL;
2734
2735         /* convert sg[] to pages[] */
2736         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2737                 pages[i] = sg_page(sg);
2738         }
2739
2740         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2741         kfree(pages);
2742         if (!cmd->t_data_vmap)
2743                 return NULL;
2744
2745         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2746 }
2747 EXPORT_SYMBOL(transport_kmap_data_sg);
2748
2749 void transport_kunmap_data_sg(struct se_cmd *cmd)
2750 {
2751         if (!cmd->t_data_nents) {
2752                 return;
2753         } else if (cmd->t_data_nents == 1) {
2754                 kunmap(sg_page(cmd->t_data_sg));
2755                 return;
2756         }
2757
2758         vunmap(cmd->t_data_vmap);
2759         cmd->t_data_vmap = NULL;
2760 }
2761 EXPORT_SYMBOL(transport_kunmap_data_sg);
2762
2763 int
2764 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2765                  bool zero_page, bool chainable)
2766 {
2767         gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
2768
2769         *sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
2770         return *sgl ? 0 : -ENOMEM;
2771 }
2772 EXPORT_SYMBOL(target_alloc_sgl);
2773
2774 /*
2775  * Allocate any required resources to execute the command.  For writes we
2776  * might not have the payload yet, so notify the fabric via a call to
2777  * ->write_pending instead. Otherwise place it on the execution queue.
2778  */
2779 sense_reason_t
2780 transport_generic_new_cmd(struct se_cmd *cmd)
2781 {
2782         unsigned long flags;
2783         int ret = 0;
2784         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2785
2786         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2787             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2788                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2789                                        cmd->prot_length, true, false);
2790                 if (ret < 0)
2791                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2792         }
2793
2794         /*
2795          * Determine if the TCM fabric module has already allocated physical
2796          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2797          * beforehand.
2798          */
2799         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2800             cmd->data_length) {
2801
2802                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2803                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2804                         u32 bidi_length;
2805
2806                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2807                                 bidi_length = cmd->t_task_nolb *
2808                                               cmd->se_dev->dev_attrib.block_size;
2809                         else
2810                                 bidi_length = cmd->data_length;
2811
2812                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2813                                                &cmd->t_bidi_data_nents,
2814                                                bidi_length, zero_flag, false);
2815                         if (ret < 0)
2816                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2817                 }
2818
2819                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2820                                        cmd->data_length, zero_flag, false);
2821                 if (ret < 0)
2822                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2823         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2824                     cmd->data_length) {
2825                 /*
2826                  * Special case for COMPARE_AND_WRITE with fabrics
2827                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2828                  */
2829                 u32 caw_length = cmd->t_task_nolb *
2830                                  cmd->se_dev->dev_attrib.block_size;
2831
2832                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2833                                        &cmd->t_bidi_data_nents,
2834                                        caw_length, zero_flag, false);
2835                 if (ret < 0)
2836                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2837         }
2838         /*
2839          * If this command is not a write we can execute it right here,
2840          * for write buffers we need to notify the fabric driver first
2841          * and let it call back once the write buffers are ready.
2842          */
2843         target_add_to_state_list(cmd);
2844         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2845                 target_execute_cmd(cmd);
2846                 return 0;
2847         }
2848
2849         spin_lock_irqsave(&cmd->t_state_lock, flags);
2850         cmd->t_state = TRANSPORT_WRITE_PENDING;
2851         /*
2852          * Determine if frontend context caller is requesting the stopping of
2853          * this command for frontend exceptions.
2854          */
2855         if (cmd->transport_state & CMD_T_STOP &&
2856             !cmd->se_tfo->write_pending_must_be_called) {
2857                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2858                          __func__, __LINE__, cmd->tag);
2859
2860                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2861
2862                 complete_all(&cmd->t_transport_stop_comp);
2863                 return 0;
2864         }
2865         cmd->transport_state &= ~CMD_T_ACTIVE;
2866         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2867
2868         ret = cmd->se_tfo->write_pending(cmd);
2869         if (ret)
2870                 goto queue_full;
2871
2872         return 0;
2873
2874 queue_full:
2875         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2876         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2877         return 0;
2878 }
2879 EXPORT_SYMBOL(transport_generic_new_cmd);
2880
2881 static void transport_write_pending_qf(struct se_cmd *cmd)
2882 {
2883         unsigned long flags;
2884         int ret;
2885         bool stop;
2886
2887         spin_lock_irqsave(&cmd->t_state_lock, flags);
2888         stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2889         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2890
2891         if (stop) {
2892                 pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2893                         __func__, __LINE__, cmd->tag);
2894                 complete_all(&cmd->t_transport_stop_comp);
2895                 return;
2896         }
2897
2898         ret = cmd->se_tfo->write_pending(cmd);
2899         if (ret) {
2900                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2901                          cmd);
2902                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2903         }
2904 }
2905
2906 static bool
2907 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2908                            unsigned long *flags);
2909
2910 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2911 {
2912         unsigned long flags;
2913
2914         spin_lock_irqsave(&cmd->t_state_lock, flags);
2915         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2916         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2917 }
2918
2919 /*
2920  * Call target_put_sess_cmd() and wait until target_release_cmd_kref(@cmd) has
2921  * finished.
2922  */
2923 void target_put_cmd_and_wait(struct se_cmd *cmd)
2924 {
2925         DECLARE_COMPLETION_ONSTACK(compl);
2926
2927         WARN_ON_ONCE(cmd->abrt_compl);
2928         cmd->abrt_compl = &compl;
2929         target_put_sess_cmd(cmd);
2930         wait_for_completion(&compl);
2931 }
2932
2933 /*
2934  * This function is called by frontend drivers after processing of a command
2935  * has finished.
2936  *
2937  * The protocol for ensuring that either the regular frontend command
2938  * processing flow or target_handle_abort() code drops one reference is as
2939  * follows:
2940  * - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
2941  *   the frontend driver to call this function synchronously or asynchronously.
2942  *   That will cause one reference to be dropped.
2943  * - During regular command processing the target core sets CMD_T_COMPLETE
2944  *   before invoking one of the .queue_*() functions.
2945  * - The code that aborts commands skips commands and TMFs for which
2946  *   CMD_T_COMPLETE has been set.
2947  * - CMD_T_ABORTED is set atomically after the CMD_T_COMPLETE check for
2948  *   commands that will be aborted.
2949  * - If the CMD_T_ABORTED flag is set but CMD_T_TAS has not been set
2950  *   transport_generic_free_cmd() skips its call to target_put_sess_cmd().
2951  * - For aborted commands for which CMD_T_TAS has been set .queue_status() will
2952  *   be called and will drop a reference.
2953  * - For aborted commands for which CMD_T_TAS has not been set .aborted_task()
2954  *   will be called. target_handle_abort() will drop the final reference.
2955  */
2956 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2957 {
2958         DECLARE_COMPLETION_ONSTACK(compl);
2959         int ret = 0;
2960         bool aborted = false, tas = false;
2961
2962         if (wait_for_tasks)
2963                 target_wait_free_cmd(cmd, &aborted, &tas);
2964
2965         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD) {
2966                 /*
2967                  * Handle WRITE failure case where transport_generic_new_cmd()
2968                  * has already added se_cmd to state_list, but fabric has
2969                  * failed command before I/O submission.
2970                  */
2971                 if (cmd->state_active)
2972                         target_remove_from_state_list(cmd);
2973
2974                 if (cmd->se_lun)
2975                         transport_lun_remove_cmd(cmd);
2976         }
2977         if (aborted)
2978                 cmd->free_compl = &compl;
2979         ret = target_put_sess_cmd(cmd);
2980         if (aborted) {
2981                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2982                 wait_for_completion(&compl);
2983                 ret = 1;
2984         }
2985         return ret;
2986 }
2987 EXPORT_SYMBOL(transport_generic_free_cmd);
2988
2989 /**
2990  * target_get_sess_cmd - Verify the session is accepting cmds and take ref
2991  * @se_cmd:     command descriptor to add
2992  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2993  */
2994 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2995 {
2996         int ret = 0;
2997
2998         /*
2999          * Add a second kref if the fabric caller is expecting to handle
3000          * fabric acknowledgement that requires two target_put_sess_cmd()
3001          * invocations before se_cmd descriptor release.
3002          */
3003         if (ack_kref) {
3004                 kref_get(&se_cmd->cmd_kref);
3005                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
3006         }
3007
3008         /*
3009          * Users like xcopy do not use counters since they never do a stop
3010          * and wait.
3011          */
3012         if (se_cmd->cmd_cnt) {
3013                 if (!percpu_ref_tryget_live(&se_cmd->cmd_cnt->refcnt))
3014                         ret = -ESHUTDOWN;
3015         }
3016         if (ret && ack_kref)
3017                 target_put_sess_cmd(se_cmd);
3018
3019         return ret;
3020 }
3021 EXPORT_SYMBOL(target_get_sess_cmd);
3022
3023 static void target_free_cmd_mem(struct se_cmd *cmd)
3024 {
3025         transport_free_pages(cmd);
3026
3027         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
3028                 core_tmr_release_req(cmd->se_tmr_req);
3029         if (cmd->t_task_cdb != cmd->__t_task_cdb)
3030                 kfree(cmd->t_task_cdb);
3031 }
3032
3033 static void target_release_cmd_kref(struct kref *kref)
3034 {
3035         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
3036         struct target_cmd_counter *cmd_cnt = se_cmd->cmd_cnt;
3037         struct completion *free_compl = se_cmd->free_compl;
3038         struct completion *abrt_compl = se_cmd->abrt_compl;
3039
3040         target_free_cmd_mem(se_cmd);
3041         se_cmd->se_tfo->release_cmd(se_cmd);
3042         if (free_compl)
3043                 complete(free_compl);
3044         if (abrt_compl)
3045                 complete(abrt_compl);
3046
3047         if (cmd_cnt)
3048                 percpu_ref_put(&cmd_cnt->refcnt);
3049 }
3050
3051 /**
3052  * target_put_sess_cmd - decrease the command reference count
3053  * @se_cmd:     command to drop a reference from
3054  *
3055  * Returns 1 if and only if this target_put_sess_cmd() call caused the
3056  * refcount to drop to zero. Returns zero otherwise.
3057  */
3058 int target_put_sess_cmd(struct se_cmd *se_cmd)
3059 {
3060         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
3061 }
3062 EXPORT_SYMBOL(target_put_sess_cmd);
3063
3064 static const char *data_dir_name(enum dma_data_direction d)
3065 {
3066         switch (d) {
3067         case DMA_BIDIRECTIONAL: return "BIDI";
3068         case DMA_TO_DEVICE:     return "WRITE";
3069         case DMA_FROM_DEVICE:   return "READ";
3070         case DMA_NONE:          return "NONE";
3071         }
3072
3073         return "(?)";
3074 }
3075
3076 static const char *cmd_state_name(enum transport_state_table t)
3077 {
3078         switch (t) {
3079         case TRANSPORT_NO_STATE:        return "NO_STATE";
3080         case TRANSPORT_NEW_CMD:         return "NEW_CMD";
3081         case TRANSPORT_WRITE_PENDING:   return "WRITE_PENDING";
3082         case TRANSPORT_PROCESSING:      return "PROCESSING";
3083         case TRANSPORT_COMPLETE:        return "COMPLETE";
3084         case TRANSPORT_ISTATE_PROCESSING:
3085                                         return "ISTATE_PROCESSING";
3086         case TRANSPORT_COMPLETE_QF_WP:  return "COMPLETE_QF_WP";
3087         case TRANSPORT_COMPLETE_QF_OK:  return "COMPLETE_QF_OK";
3088         case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
3089         }
3090
3091         return "(?)";
3092 }
3093
3094 static void target_append_str(char **str, const char *txt)
3095 {
3096         char *prev = *str;
3097
3098         *str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
3099                 kstrdup(txt, GFP_ATOMIC);
3100         kfree(prev);
3101 }
3102
3103 /*
3104  * Convert a transport state bitmask into a string. The caller is
3105  * responsible for freeing the returned pointer.
3106  */
3107 static char *target_ts_to_str(u32 ts)
3108 {
3109         char *str = NULL;
3110
3111         if (ts & CMD_T_ABORTED)
3112                 target_append_str(&str, "aborted");
3113         if (ts & CMD_T_ACTIVE)
3114                 target_append_str(&str, "active");
3115         if (ts & CMD_T_COMPLETE)
3116                 target_append_str(&str, "complete");
3117         if (ts & CMD_T_SENT)
3118                 target_append_str(&str, "sent");
3119         if (ts & CMD_T_STOP)
3120                 target_append_str(&str, "stop");
3121         if (ts & CMD_T_FABRIC_STOP)
3122                 target_append_str(&str, "fabric_stop");
3123
3124         return str;
3125 }
3126
3127 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
3128 {
3129         switch (tmf) {
3130         case TMR_ABORT_TASK:            return "ABORT_TASK";
3131         case TMR_ABORT_TASK_SET:        return "ABORT_TASK_SET";
3132         case TMR_CLEAR_ACA:             return "CLEAR_ACA";
3133         case TMR_CLEAR_TASK_SET:        return "CLEAR_TASK_SET";
3134         case TMR_LUN_RESET:             return "LUN_RESET";
3135         case TMR_TARGET_WARM_RESET:     return "TARGET_WARM_RESET";
3136         case TMR_TARGET_COLD_RESET:     return "TARGET_COLD_RESET";
3137         case TMR_LUN_RESET_PRO:         return "LUN_RESET_PRO";
3138         case TMR_UNKNOWN:               break;
3139         }
3140         return "(?)";
3141 }
3142
3143 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
3144 {
3145         char *ts_str = target_ts_to_str(cmd->transport_state);
3146         const u8 *cdb = cmd->t_task_cdb;
3147         struct se_tmr_req *tmf = cmd->se_tmr_req;
3148
3149         if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
3150                 pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
3151                          pfx, cdb[0], cdb[1], cmd->tag,
3152                          data_dir_name(cmd->data_direction),
3153                          cmd->se_tfo->get_cmd_state(cmd),
3154                          cmd_state_name(cmd->t_state), cmd->data_length,
3155                          kref_read(&cmd->cmd_kref), ts_str);
3156         } else {
3157                 pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
3158                          pfx, target_tmf_name(tmf->function), cmd->tag,
3159                          tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
3160                          cmd_state_name(cmd->t_state),
3161                          kref_read(&cmd->cmd_kref), ts_str);
3162         }
3163         kfree(ts_str);
3164 }
3165 EXPORT_SYMBOL(target_show_cmd);
3166
3167 static void target_stop_cmd_counter_confirm(struct percpu_ref *ref)
3168 {
3169         struct target_cmd_counter *cmd_cnt = container_of(ref,
3170                                                 struct target_cmd_counter,
3171                                                 refcnt);
3172         complete_all(&cmd_cnt->stop_done);
3173 }
3174
3175 /**
3176  * target_stop_cmd_counter - Stop new IO from being added to the counter.
3177  * @cmd_cnt: counter to stop
3178  */
3179 void target_stop_cmd_counter(struct target_cmd_counter *cmd_cnt)
3180 {
3181         pr_debug("Stopping command counter.\n");
3182         if (!atomic_cmpxchg(&cmd_cnt->stopped, 0, 1))
3183                 percpu_ref_kill_and_confirm(&cmd_cnt->refcnt,
3184                                             target_stop_cmd_counter_confirm);
3185 }
3186 EXPORT_SYMBOL_GPL(target_stop_cmd_counter);
3187
3188 /**
3189  * target_stop_session - Stop new IO from being queued on the session.
3190  * @se_sess: session to stop
3191  */
3192 void target_stop_session(struct se_session *se_sess)
3193 {
3194         target_stop_cmd_counter(se_sess->cmd_cnt);
3195 }
3196 EXPORT_SYMBOL(target_stop_session);
3197
3198 /**
3199  * target_wait_for_cmds - Wait for outstanding cmds.
3200  * @cmd_cnt: counter to wait for active I/O for.
3201  */
3202 void target_wait_for_cmds(struct target_cmd_counter *cmd_cnt)
3203 {
3204         int ret;
3205
3206         WARN_ON_ONCE(!atomic_read(&cmd_cnt->stopped));
3207
3208         do {
3209                 pr_debug("Waiting for running cmds to complete.\n");
3210                 ret = wait_event_timeout(cmd_cnt->refcnt_wq,
3211                                          percpu_ref_is_zero(&cmd_cnt->refcnt),
3212                                          180 * HZ);
3213         } while (ret <= 0);
3214
3215         wait_for_completion(&cmd_cnt->stop_done);
3216         pr_debug("Waiting for cmds done.\n");
3217 }
3218 EXPORT_SYMBOL_GPL(target_wait_for_cmds);
3219
3220 /**
3221  * target_wait_for_sess_cmds - Wait for outstanding commands
3222  * @se_sess: session to wait for active I/O
3223  */
3224 void target_wait_for_sess_cmds(struct se_session *se_sess)
3225 {
3226         target_wait_for_cmds(se_sess->cmd_cnt);
3227 }
3228 EXPORT_SYMBOL(target_wait_for_sess_cmds);
3229
3230 /*
3231  * Prevent that new percpu_ref_tryget_live() calls succeed and wait until
3232  * all references to the LUN have been released. Called during LUN shutdown.
3233  */
3234 void transport_clear_lun_ref(struct se_lun *lun)
3235 {
3236         percpu_ref_kill(&lun->lun_ref);
3237         wait_for_completion(&lun->lun_shutdown_comp);
3238 }
3239
3240 static bool
3241 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
3242                            bool *aborted, bool *tas, unsigned long *flags)
3243         __releases(&cmd->t_state_lock)
3244         __acquires(&cmd->t_state_lock)
3245 {
3246         lockdep_assert_held(&cmd->t_state_lock);
3247
3248         if (fabric_stop)
3249                 cmd->transport_state |= CMD_T_FABRIC_STOP;
3250
3251         if (cmd->transport_state & CMD_T_ABORTED)
3252                 *aborted = true;
3253
3254         if (cmd->transport_state & CMD_T_TAS)
3255                 *tas = true;
3256
3257         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
3258             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3259                 return false;
3260
3261         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
3262             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3263                 return false;
3264
3265         if (!(cmd->transport_state & CMD_T_ACTIVE))
3266                 return false;
3267
3268         if (fabric_stop && *aborted)
3269                 return false;
3270
3271         cmd->transport_state |= CMD_T_STOP;
3272
3273         target_show_cmd("wait_for_tasks: Stopping ", cmd);
3274
3275         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
3276
3277         while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
3278                                             180 * HZ))
3279                 target_show_cmd("wait for tasks: ", cmd);
3280
3281         spin_lock_irqsave(&cmd->t_state_lock, *flags);
3282         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
3283
3284         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
3285                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
3286
3287         return true;
3288 }
3289
3290 /**
3291  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3292  * @cmd: command to wait on
3293  */
3294 bool transport_wait_for_tasks(struct se_cmd *cmd)
3295 {
3296         unsigned long flags;
3297         bool ret, aborted = false, tas = false;
3298
3299         spin_lock_irqsave(&cmd->t_state_lock, flags);
3300         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3301         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3302
3303         return ret;
3304 }
3305 EXPORT_SYMBOL(transport_wait_for_tasks);
3306
3307 struct sense_detail {
3308         u8 key;
3309         u8 asc;
3310         u8 ascq;
3311         bool add_sense_info;
3312 };
3313
3314 static const struct sense_detail sense_detail_table[] = {
3315         [TCM_NO_SENSE] = {
3316                 .key = NOT_READY
3317         },
3318         [TCM_NON_EXISTENT_LUN] = {
3319                 .key = ILLEGAL_REQUEST,
3320                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3321         },
3322         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
3323                 .key = ILLEGAL_REQUEST,
3324                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3325         },
3326         [TCM_SECTOR_COUNT_TOO_MANY] = {
3327                 .key = ILLEGAL_REQUEST,
3328                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3329         },
3330         [TCM_UNKNOWN_MODE_PAGE] = {
3331                 .key = ILLEGAL_REQUEST,
3332                 .asc = 0x24, /* INVALID FIELD IN CDB */
3333         },
3334         [TCM_CHECK_CONDITION_ABORT_CMD] = {
3335                 .key = ABORTED_COMMAND,
3336                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3337                 .ascq = 0x03,
3338         },
3339         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
3340                 .key = ABORTED_COMMAND,
3341                 .asc = 0x0c, /* WRITE ERROR */
3342                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3343         },
3344         [TCM_INVALID_CDB_FIELD] = {
3345                 .key = ILLEGAL_REQUEST,
3346                 .asc = 0x24, /* INVALID FIELD IN CDB */
3347         },
3348         [TCM_INVALID_PARAMETER_LIST] = {
3349                 .key = ILLEGAL_REQUEST,
3350                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3351         },
3352         [TCM_TOO_MANY_TARGET_DESCS] = {
3353                 .key = ILLEGAL_REQUEST,
3354                 .asc = 0x26,
3355                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3356         },
3357         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3358                 .key = ILLEGAL_REQUEST,
3359                 .asc = 0x26,
3360                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3361         },
3362         [TCM_TOO_MANY_SEGMENT_DESCS] = {
3363                 .key = ILLEGAL_REQUEST,
3364                 .asc = 0x26,
3365                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3366         },
3367         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3368                 .key = ILLEGAL_REQUEST,
3369                 .asc = 0x26,
3370                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3371         },
3372         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3373                 .key = ILLEGAL_REQUEST,
3374                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3375         },
3376         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3377                 .key = ILLEGAL_REQUEST,
3378                 .asc = 0x0c, /* WRITE ERROR */
3379                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3380         },
3381         [TCM_SERVICE_CRC_ERROR] = {
3382                 .key = ABORTED_COMMAND,
3383                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3384                 .ascq = 0x05, /* N/A */
3385         },
3386         [TCM_SNACK_REJECTED] = {
3387                 .key = ABORTED_COMMAND,
3388                 .asc = 0x11, /* READ ERROR */
3389                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3390         },
3391         [TCM_WRITE_PROTECTED] = {
3392                 .key = DATA_PROTECT,
3393                 .asc = 0x27, /* WRITE PROTECTED */
3394         },
3395         [TCM_ADDRESS_OUT_OF_RANGE] = {
3396                 .key = ILLEGAL_REQUEST,
3397                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3398         },
3399         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3400                 .key = UNIT_ATTENTION,
3401         },
3402         [TCM_MISCOMPARE_VERIFY] = {
3403                 .key = MISCOMPARE,
3404                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3405                 .ascq = 0x00,
3406                 .add_sense_info = true,
3407         },
3408         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3409                 .key = ABORTED_COMMAND,
3410                 .asc = 0x10,
3411                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3412                 .add_sense_info = true,
3413         },
3414         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3415                 .key = ABORTED_COMMAND,
3416                 .asc = 0x10,
3417                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3418                 .add_sense_info = true,
3419         },
3420         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3421                 .key = ABORTED_COMMAND,
3422                 .asc = 0x10,
3423                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3424                 .add_sense_info = true,
3425         },
3426         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3427                 .key = COPY_ABORTED,
3428                 .asc = 0x0d,
3429                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3430
3431         },
3432         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3433                 /*
3434                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
3435                  * Solaris initiators.  Returning NOT READY instead means the
3436                  * operations will be retried a finite number of times and we
3437                  * can survive intermittent errors.
3438                  */
3439                 .key = NOT_READY,
3440                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3441         },
3442         [TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3443                 /*
3444                  * From spc4r22 section5.7.7,5.7.8
3445                  * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3446                  * or a REGISTER AND IGNORE EXISTING KEY service action or
3447                  * REGISTER AND MOVE service actionis attempted,
3448                  * but there are insufficient device server resources to complete the
3449                  * operation, then the command shall be terminated with CHECK CONDITION
3450                  * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3451                  * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3452                  */
3453                 .key = ILLEGAL_REQUEST,
3454                 .asc = 0x55,
3455                 .ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3456         },
3457         [TCM_INVALID_FIELD_IN_COMMAND_IU] = {
3458                 .key = ILLEGAL_REQUEST,
3459                 .asc = 0x0e,
3460                 .ascq = 0x03, /* INVALID FIELD IN COMMAND INFORMATION UNIT */
3461         },
3462         [TCM_ALUA_TG_PT_STANDBY] = {
3463                 .key = NOT_READY,
3464                 .asc = 0x04,
3465                 .ascq = ASCQ_04H_ALUA_TG_PT_STANDBY,
3466         },
3467         [TCM_ALUA_TG_PT_UNAVAILABLE] = {
3468                 .key = NOT_READY,
3469                 .asc = 0x04,
3470                 .ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE,
3471         },
3472         [TCM_ALUA_STATE_TRANSITION] = {
3473                 .key = NOT_READY,
3474                 .asc = 0x04,
3475                 .ascq = ASCQ_04H_ALUA_STATE_TRANSITION,
3476         },
3477         [TCM_ALUA_OFFLINE] = {
3478                 .key = NOT_READY,
3479                 .asc = 0x04,
3480                 .ascq = ASCQ_04H_ALUA_OFFLINE,
3481         },
3482 };
3483
3484 /**
3485  * translate_sense_reason - translate a sense reason into T10 key, asc and ascq
3486  * @cmd: SCSI command in which the resulting sense buffer or SCSI status will
3487  *   be stored.
3488  * @reason: LIO sense reason code. If this argument has the value
3489  *   TCM_CHECK_CONDITION_UNIT_ATTENTION, try to dequeue a unit attention. If
3490  *   dequeuing a unit attention fails due to multiple commands being processed
3491  *   concurrently, set the command status to BUSY.
3492  *
3493  * Return: 0 upon success or -EINVAL if the sense buffer is too small.
3494  */
3495 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3496 {
3497         const struct sense_detail *sd;
3498         u8 *buffer = cmd->sense_buffer;
3499         int r = (__force int)reason;
3500         u8 key, asc, ascq;
3501         bool desc_format = target_sense_desc_format(cmd->se_dev);
3502
3503         if (r < ARRAY_SIZE(sense_detail_table) && sense_detail_table[r].key)
3504                 sd = &sense_detail_table[r];
3505         else
3506                 sd = &sense_detail_table[(__force int)
3507                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3508
3509         key = sd->key;
3510         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3511                 if (!core_scsi3_ua_for_check_condition(cmd, &key, &asc,
3512                                                        &ascq)) {
3513                         cmd->scsi_status = SAM_STAT_BUSY;
3514                         return;
3515                 }
3516         } else {
3517                 WARN_ON_ONCE(sd->asc == 0);
3518                 asc = sd->asc;
3519                 ascq = sd->ascq;
3520         }
3521
3522         cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3523         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3524         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3525         scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
3526         if (sd->add_sense_info)
3527                 WARN_ON_ONCE(scsi_set_sense_information(buffer,
3528                                                         cmd->scsi_sense_length,
3529                                                         cmd->sense_info) < 0);
3530 }
3531
3532 int
3533 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3534                 sense_reason_t reason, int from_transport)
3535 {
3536         unsigned long flags;
3537
3538         WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3539
3540         spin_lock_irqsave(&cmd->t_state_lock, flags);
3541         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3542                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3543                 return 0;
3544         }
3545         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3546         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3547
3548         if (!from_transport)
3549                 translate_sense_reason(cmd, reason);
3550
3551         trace_target_cmd_complete(cmd);
3552         return cmd->se_tfo->queue_status(cmd);
3553 }
3554 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3555
3556 /**
3557  * target_send_busy - Send SCSI BUSY status back to the initiator
3558  * @cmd: SCSI command for which to send a BUSY reply.
3559  *
3560  * Note: Only call this function if target_submit_cmd*() failed.
3561  */
3562 int target_send_busy(struct se_cmd *cmd)
3563 {
3564         WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3565
3566         cmd->scsi_status = SAM_STAT_BUSY;
3567         trace_target_cmd_complete(cmd);
3568         return cmd->se_tfo->queue_status(cmd);
3569 }
3570 EXPORT_SYMBOL(target_send_busy);
3571
3572 static void target_tmr_work(struct work_struct *work)
3573 {
3574         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3575         struct se_device *dev = cmd->se_dev;
3576         struct se_tmr_req *tmr = cmd->se_tmr_req;
3577         int ret;
3578
3579         if (cmd->transport_state & CMD_T_ABORTED)
3580                 goto aborted;
3581
3582         switch (tmr->function) {
3583         case TMR_ABORT_TASK:
3584                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3585                 break;
3586         case TMR_ABORT_TASK_SET:
3587         case TMR_CLEAR_ACA:
3588         case TMR_CLEAR_TASK_SET:
3589                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3590                 break;
3591         case TMR_LUN_RESET:
3592                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3593                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3594                                          TMR_FUNCTION_REJECTED;
3595                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3596                         target_dev_ua_allocate(dev, 0x29,
3597                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3598                 }
3599                 break;
3600         case TMR_TARGET_WARM_RESET:
3601                 tmr->response = TMR_FUNCTION_REJECTED;
3602                 break;
3603         case TMR_TARGET_COLD_RESET:
3604                 tmr->response = TMR_FUNCTION_REJECTED;
3605                 break;
3606         default:
3607                 pr_err("Unknown TMR function: 0x%02x.\n",
3608                                 tmr->function);
3609                 tmr->response = TMR_FUNCTION_REJECTED;
3610                 break;
3611         }
3612
3613         if (cmd->transport_state & CMD_T_ABORTED)
3614                 goto aborted;
3615
3616         cmd->se_tfo->queue_tm_rsp(cmd);
3617
3618         transport_lun_remove_cmd(cmd);
3619         transport_cmd_check_stop_to_fabric(cmd);
3620         return;
3621
3622 aborted:
3623         target_handle_abort(cmd);
3624 }
3625
3626 int transport_generic_handle_tmr(
3627         struct se_cmd *cmd)
3628 {
3629         unsigned long flags;
3630         bool aborted = false;
3631
3632         spin_lock_irqsave(&cmd->t_state_lock, flags);
3633         if (cmd->transport_state & CMD_T_ABORTED) {
3634                 aborted = true;
3635         } else {
3636                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3637                 cmd->transport_state |= CMD_T_ACTIVE;
3638         }
3639         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3640
3641         if (aborted) {
3642                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d ref_tag: %llu tag: %llu\n",
3643                                     cmd->se_tmr_req->function,
3644                                     cmd->se_tmr_req->ref_task_tag, cmd->tag);
3645                 target_handle_abort(cmd);
3646                 return 0;
3647         }
3648
3649         INIT_WORK(&cmd->work, target_tmr_work);
3650         schedule_work(&cmd->work);
3651         return 0;
3652 }
3653 EXPORT_SYMBOL(transport_generic_handle_tmr);
3654
3655 bool
3656 target_check_wce(struct se_device *dev)
3657 {
3658         bool wce = false;
3659
3660         if (dev->transport->get_write_cache)
3661                 wce = dev->transport->get_write_cache(dev);
3662         else if (dev->dev_attrib.emulate_write_cache > 0)
3663                 wce = true;
3664
3665         return wce;
3666 }
3667
3668 bool
3669 target_check_fua(struct se_device *dev)
3670 {
3671         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3672 }