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