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