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