drivers/target/target_core_transport.c

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