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