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->execute_task_lock, flags);
 654         if (cmd->state_active) {
 655                 list_del(&cmd->state_list);
 656                 cmd->state_active = false;
 657         }
 658         spin_unlock_irqrestore(&dev->execute_task_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         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 870                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 871         else
 872                 queue_work(target_completion_wq, &cmd->work);
 873 }
 874 EXPORT_SYMBOL(target_complete_cmd);
 875
 876 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 877 {
 878         if ((scsi_status == SAM_STAT_GOOD ||
 879              cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
 880             length < cmd->data_length) {
 881                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 882                         cmd->residual_count += cmd->data_length - length;
 883                 } else {
 884                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 885                         cmd->residual_count = cmd->data_length - length;
 886                 }
 887
 888                 cmd->data_length = length;
 889         }
 890
 891         target_complete_cmd(cmd, scsi_status);
 892 }
 893 EXPORT_SYMBOL(target_complete_cmd_with_length);
 894
 895 static void target_add_to_state_list(struct se_cmd *cmd)
 896 {
 897         struct se_device *dev = cmd->se_dev;
 898         unsigned long flags;
 899
 900         spin_lock_irqsave(&dev->execute_task_lock, flags);
 901         if (!cmd->state_active) {
 902                 list_add_tail(&cmd->state_list, &dev->state_list);
 903                 cmd->state_active = true;
 904         }
 905         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 906 }
 907
 908 /*
 909  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 910  */
 911 static void transport_write_pending_qf(struct se_cmd *cmd);
 912 static void transport_complete_qf(struct se_cmd *cmd);
 913
 914 void target_qf_do_work(struct work_struct *work)
 915 {
 916         struct se_device *dev = container_of(work, struct se_device,
 917                                         qf_work_queue);
 918         LIST_HEAD(qf_cmd_list);
 919         struct se_cmd *cmd, *cmd_tmp;
 920
 921         spin_lock_irq(&dev->qf_cmd_lock);
 922         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 923         spin_unlock_irq(&dev->qf_cmd_lock);
 924
 925         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 926                 list_del(&cmd->se_qf_node);
 927                 atomic_dec_mb(&dev->dev_qf_count);
 928
 929                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 930                         " context: %s\n", cmd->se_tfo->fabric_name, cmd,
 931                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 932                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 933                         : "UNKNOWN");
 934
 935                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 936                         transport_write_pending_qf(cmd);
 937                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 938                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 939                         transport_complete_qf(cmd);
 940         }
 941 }
 942
 943 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 944 {
 945         switch (cmd->data_direction) {
 946         case DMA_NONE:
 947                 return "NONE";
 948         case DMA_FROM_DEVICE:
 949                 return "READ";
 950         case DMA_TO_DEVICE:
 951                 return "WRITE";
 952         case DMA_BIDIRECTIONAL:
 953                 return "BIDI";
 954         default:
 955                 break;
 956         }
 957
 958         return "UNKNOWN";
 959 }
 960
 961 void transport_dump_dev_state(
 962         struct se_device *dev,
 963         char *b,
 964         int *bl)
 965 {
 966         *bl += sprintf(b + *bl, "Status: ");
 967         if (dev->export_count)
 968                 *bl += sprintf(b + *bl, "ACTIVATED");
 969         else
 970                 *bl += sprintf(b + *bl, "DEACTIVATED");
 971
 972         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 973         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 974                 dev->dev_attrib.block_size,
 975                 dev->dev_attrib.hw_max_sectors);
 976         *bl += sprintf(b + *bl, "        ");
 977 }
 978
 979 void transport_dump_vpd_proto_id(
 980         struct t10_vpd *vpd,
 981         unsigned char *p_buf,
 982         int p_buf_len)
 983 {
 984         unsigned char buf[VPD_TMP_BUF_SIZE];
 985         int len;
 986
 987         memset(buf, 0, VPD_TMP_BUF_SIZE);
 988         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 989
 990         switch (vpd->protocol_identifier) {
 991         case 0x00:
 992                 sprintf(buf+len, "Fibre Channel\n");
 993                 break;
 994         case 0x10:
 995                 sprintf(buf+len, "Parallel SCSI\n");
 996                 break;
 997         case 0x20:
 998                 sprintf(buf+len, "SSA\n");
 999                 break;
1000         case 0x30:
1001                 sprintf(buf+len, "IEEE 1394\n");
1002                 break;
1003         case 0x40:
1004                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
1005                                 " Protocol\n");
1006                 break;
1007         case 0x50:
1008                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
1009                 break;
1010         case 0x60:
1011                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
1012                 break;
1013         case 0x70:
1014                 sprintf(buf+len, "Automation/Drive Interface Transport"
1015                                 " Protocol\n");
1016                 break;
1017         case 0x80:
1018                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
1019                 break;
1020         default:
1021                 sprintf(buf+len, "Unknown 0x%02x\n",
1022                                 vpd->protocol_identifier);
1023                 break;
1024         }
1025
1026         if (p_buf)
1027                 strncpy(p_buf, buf, p_buf_len);
1028         else
1029                 pr_debug("%s", buf);
1030 }
1031
1032 void
1033 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
1034 {
1035         /*
1036          * Check if the Protocol Identifier Valid (PIV) bit is set..
1037          *
1038          * from spc3r23.pdf section 7.5.1
1039          */
1040          if (page_83[1] & 0x80) {
1041                 vpd->protocol_identifier = (page_83[0] & 0xf0);
1042                 vpd->protocol_identifier_set = 1;
1043                 transport_dump_vpd_proto_id(vpd, NULL, 0);
1044         }
1045 }
1046 EXPORT_SYMBOL(transport_set_vpd_proto_id);
1047
1048 int transport_dump_vpd_assoc(
1049         struct t10_vpd *vpd,
1050         unsigned char *p_buf,
1051         int p_buf_len)
1052 {
1053         unsigned char buf[VPD_TMP_BUF_SIZE];
1054         int ret = 0;
1055         int len;
1056
1057         memset(buf, 0, VPD_TMP_BUF_SIZE);
1058         len = sprintf(buf, "T10 VPD Identifier Association: ");
1059
1060         switch (vpd->association) {
1061         case 0x00:
1062                 sprintf(buf+len, "addressed logical unit\n");
1063                 break;
1064         case 0x10:
1065                 sprintf(buf+len, "target port\n");
1066                 break;
1067         case 0x20:
1068                 sprintf(buf+len, "SCSI target device\n");
1069                 break;
1070         default:
1071                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
1072                 ret = -EINVAL;
1073                 break;
1074         }
1075
1076         if (p_buf)
1077                 strncpy(p_buf, buf, p_buf_len);
1078         else
1079                 pr_debug("%s", buf);
1080
1081         return ret;
1082 }
1083
1084 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
1085 {
1086         /*
1087          * The VPD identification association..
1088          *
1089          * from spc3r23.pdf Section 7.6.3.1 Table 297
1090          */
1091         vpd->association = (page_83[1] & 0x30);
1092         return transport_dump_vpd_assoc(vpd, NULL, 0);
1093 }
1094 EXPORT_SYMBOL(transport_set_vpd_assoc);
1095
1096 int transport_dump_vpd_ident_type(
1097         struct t10_vpd *vpd,
1098         unsigned char *p_buf,
1099         int p_buf_len)
1100 {
1101         unsigned char buf[VPD_TMP_BUF_SIZE];
1102         int ret = 0;
1103         int len;
1104
1105         memset(buf, 0, VPD_TMP_BUF_SIZE);
1106         len = sprintf(buf, "T10 VPD Identifier Type: ");
1107
1108         switch (vpd->device_identifier_type) {
1109         case 0x00:
1110                 sprintf(buf+len, "Vendor specific\n");
1111                 break;
1112         case 0x01:
1113                 sprintf(buf+len, "T10 Vendor ID based\n");
1114                 break;
1115         case 0x02:
1116                 sprintf(buf+len, "EUI-64 based\n");
1117                 break;
1118         case 0x03:
1119                 sprintf(buf+len, "NAA\n");
1120                 break;
1121         case 0x04:
1122                 sprintf(buf+len, "Relative target port identifier\n");
1123                 break;
1124         case 0x08:
1125                 sprintf(buf+len, "SCSI name string\n");
1126                 break;
1127         default:
1128                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1129                                 vpd->device_identifier_type);
1130                 ret = -EINVAL;
1131                 break;
1132         }
1133
1134         if (p_buf) {
1135                 if (p_buf_len < strlen(buf)+1)
1136                         return -EINVAL;
1137                 strncpy(p_buf, buf, p_buf_len);
1138         } else {
1139                 pr_debug("%s", buf);
1140         }
1141
1142         return ret;
1143 }
1144
1145 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1146 {
1147         /*
1148          * The VPD identifier type..
1149          *
1150          * from spc3r23.pdf Section 7.6.3.1 Table 298
1151          */
1152         vpd->device_identifier_type = (page_83[1] & 0x0f);
1153         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1154 }
1155 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1156
1157 int transport_dump_vpd_ident(
1158         struct t10_vpd *vpd,
1159         unsigned char *p_buf,
1160         int p_buf_len)
1161 {
1162         unsigned char buf[VPD_TMP_BUF_SIZE];
1163         int ret = 0;
1164
1165         memset(buf, 0, VPD_TMP_BUF_SIZE);
1166
1167         switch (vpd->device_identifier_code_set) {
1168         case 0x01: /* Binary */
1169                 snprintf(buf, sizeof(buf),
1170                         "T10 VPD Binary Device Identifier: %s\n",
1171                         &vpd->device_identifier[0]);
1172                 break;
1173         case 0x02: /* ASCII */
1174                 snprintf(buf, sizeof(buf),
1175                         "T10 VPD ASCII Device Identifier: %s\n",
1176                         &vpd->device_identifier[0]);
1177                 break;
1178         case 0x03: /* UTF-8 */
1179                 snprintf(buf, sizeof(buf),
1180                         "T10 VPD UTF-8 Device Identifier: %s\n",
1181                         &vpd->device_identifier[0]);
1182                 break;
1183         default:
1184                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1185                         " 0x%02x", vpd->device_identifier_code_set);
1186                 ret = -EINVAL;
1187                 break;
1188         }
1189
1190         if (p_buf)
1191                 strncpy(p_buf, buf, p_buf_len);
1192         else
1193                 pr_debug("%s", buf);
1194
1195         return ret;
1196 }
1197
1198 int
1199 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1200 {
1201         static const char hex_str[] = "0123456789abcdef";
1202         int j = 0, i = 4; /* offset to start of the identifier */
1203
1204         /*
1205          * The VPD Code Set (encoding)
1206          *
1207          * from spc3r23.pdf Section 7.6.3.1 Table 296
1208          */
1209         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1210         switch (vpd->device_identifier_code_set) {
1211         case 0x01: /* Binary */
1212                 vpd->device_identifier[j++] =
1213                                 hex_str[vpd->device_identifier_type];
1214                 while (i < (4 + page_83[3])) {
1215                         vpd->device_identifier[j++] =
1216                                 hex_str[(page_83[i] & 0xf0) >> 4];
1217                         vpd->device_identifier[j++] =
1218                                 hex_str[page_83[i] & 0x0f];
1219                         i++;
1220                 }
1221                 break;
1222         case 0x02: /* ASCII */
1223         case 0x03: /* UTF-8 */
1224                 while (i < (4 + page_83[3]))
1225                         vpd->device_identifier[j++] = page_83[i++];
1226                 break;
1227         default:
1228                 break;
1229         }
1230
1231         return transport_dump_vpd_ident(vpd, NULL, 0);
1232 }
1233 EXPORT_SYMBOL(transport_set_vpd_ident);
1234
1235 static sense_reason_t
1236 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1237                                unsigned int size)
1238 {
1239         u32 mtl;
1240
1241         if (!cmd->se_tfo->max_data_sg_nents)
1242                 return TCM_NO_SENSE;
1243         /*
1244          * Check if fabric enforced maximum SGL entries per I/O descriptor
1245          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1246          * residual_count and reduce original cmd->data_length to maximum
1247          * length based on single PAGE_SIZE entry scatter-lists.
1248          */
1249         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1250         if (cmd->data_length > mtl) {
1251                 /*
1252                  * If an existing CDB overflow is present, calculate new residual
1253                  * based on CDB size minus fabric maximum transfer length.
1254                  *
1255                  * If an existing CDB underflow is present, calculate new residual
1256                  * based on original cmd->data_length minus fabric maximum transfer
1257                  * length.
1258                  *
1259                  * Otherwise, set the underflow residual based on cmd->data_length
1260                  * minus fabric maximum transfer length.
1261                  */
1262                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1263                         cmd->residual_count = (size - mtl);
1264                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1265                         u32 orig_dl = size + cmd->residual_count;
1266                         cmd->residual_count = (orig_dl - mtl);
1267                 } else {
1268                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1269                         cmd->residual_count = (cmd->data_length - mtl);
1270                 }
1271                 cmd->data_length = mtl;
1272                 /*
1273                  * Reset sbc_check_prot() calculated protection payload
1274                  * length based upon the new smaller MTL.
1275                  */
1276                 if (cmd->prot_length) {
1277                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1278                         cmd->prot_length = dev->prot_length * sectors;
1279                 }
1280         }
1281         return TCM_NO_SENSE;
1282 }
1283
1284 /**
1285  * target_cmd_size_check - Check whether there will be a residual.
1286  * @cmd: SCSI command.
1287  * @size: Data buffer size derived from CDB. The data buffer size provided by
1288  *   the SCSI transport driver is available in @cmd->data_length.
1289  *
1290  * Compare the data buffer size from the CDB with the data buffer limit from the transport
1291  * header. Set @cmd->residual_count and SCF_OVERFLOW_BIT or SCF_UNDERFLOW_BIT if necessary.
1292  *
1293  * Note: target drivers set @cmd->data_length by calling transport_init_se_cmd().
1294  *
1295  * Return: TCM_NO_SENSE
1296  */
1297 sense_reason_t
1298 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1299 {
1300         struct se_device *dev = cmd->se_dev;
1301
1302         if (cmd->unknown_data_length) {
1303                 cmd->data_length = size;
1304         } else if (size != cmd->data_length) {
1305                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1306                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1307                         " 0x%02x\n", cmd->se_tfo->fabric_name,
1308                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1309
1310                 if (cmd->data_direction == DMA_TO_DEVICE) {
1311                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1312                                 pr_err_ratelimited("Rejecting underflow/overflow"
1313                                                    " for WRITE data CDB\n");
1314                                 return TCM_INVALID_CDB_FIELD;
1315                         }
1316                         /*
1317                          * Some fabric drivers like iscsi-target still expect to
1318                          * always reject overflow writes.  Reject this case until
1319                          * full fabric driver level support for overflow writes
1320                          * is introduced tree-wide.
1321                          */
1322                         if (size > cmd->data_length) {
1323                                 pr_err_ratelimited("Rejecting overflow for"
1324                                                    " WRITE control CDB\n");
1325                                 return TCM_INVALID_CDB_FIELD;
1326                         }
1327                 }
1328                 /*
1329                  * Reject READ_* or WRITE_* with overflow/underflow for
1330                  * type SCF_SCSI_DATA_CDB.
1331                  */
1332                 if (dev->dev_attrib.block_size != 512)  {
1333                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1334                                 " CDB on non 512-byte sector setup subsystem"
1335                                 " plugin: %s\n", dev->transport->name);
1336                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1337                         return TCM_INVALID_CDB_FIELD;
1338                 }
1339                 /*
1340                  * For the overflow case keep the existing fabric provided
1341                  * ->data_length.  Otherwise for the underflow case, reset
1342                  * ->data_length to the smaller SCSI expected data transfer
1343                  * length.
1344                  */
1345                 if (size > cmd->data_length) {
1346                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1347                         cmd->residual_count = (size - cmd->data_length);
1348                 } else {
1349                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1350                         cmd->residual_count = (cmd->data_length - size);
1351                         cmd->data_length = size;
1352                 }
1353         }
1354
1355         return target_check_max_data_sg_nents(cmd, dev, size);
1356
1357 }
1358
1359 /*
1360  * Used by fabric modules containing a local struct se_cmd within their
1361  * fabric dependent per I/O descriptor.
1362  *
1363  * Preserves the value of @cmd->tag.
1364  */
1365 void transport_init_se_cmd(
1366         struct se_cmd *cmd,
1367         const struct target_core_fabric_ops *tfo,
1368         struct se_session *se_sess,
1369         u32 data_length,
1370         int data_direction,
1371         int task_attr,
1372         unsigned char *sense_buffer, u64 unpacked_lun)
1373 {
1374         INIT_LIST_HEAD(&cmd->se_delayed_node);
1375         INIT_LIST_HEAD(&cmd->se_qf_node);
1376         INIT_LIST_HEAD(&cmd->se_cmd_list);
1377         INIT_LIST_HEAD(&cmd->state_list);
1378         init_completion(&cmd->t_transport_stop_comp);
1379         cmd->free_compl = NULL;
1380         cmd->abrt_compl = NULL;
1381         spin_lock_init(&cmd->t_state_lock);
1382         INIT_WORK(&cmd->work, NULL);
1383         kref_init(&cmd->cmd_kref);
1384
1385         cmd->se_tfo = tfo;
1386         cmd->se_sess = se_sess;
1387         cmd->data_length = data_length;
1388         cmd->data_direction = data_direction;
1389         cmd->sam_task_attr = task_attr;
1390         cmd->sense_buffer = sense_buffer;
1391         cmd->orig_fe_lun = unpacked_lun;
1392
1393         cmd->state_active = false;
1394 }
1395 EXPORT_SYMBOL(transport_init_se_cmd);
1396
1397 static sense_reason_t
1398 transport_check_alloc_task_attr(struct se_cmd *cmd)
1399 {
1400         struct se_device *dev = cmd->se_dev;
1401
1402         /*
1403          * Check if SAM Task Attribute emulation is enabled for this
1404          * struct se_device storage object
1405          */
1406         if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1407                 return 0;
1408
1409         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1410                 pr_debug("SAM Task Attribute ACA"
1411                         " emulation is not supported\n");
1412                 return TCM_INVALID_CDB_FIELD;
1413         }
1414
1415         return 0;
1416 }
1417
1418 sense_reason_t
1419 target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb)
1420 {
1421         sense_reason_t ret;
1422
1423         cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1424         /*
1425          * Ensure that the received CDB is less than the max (252 + 8) bytes
1426          * for VARIABLE_LENGTH_CMD
1427          */
1428         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1429                 pr_err("Received SCSI CDB with command_size: %d that"
1430                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1431                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1432                 ret = TCM_INVALID_CDB_FIELD;
1433                 goto err;
1434         }
1435         /*
1436          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1437          * allocate the additional extended CDB buffer now..  Otherwise
1438          * setup the pointer from __t_task_cdb to t_task_cdb.
1439          */
1440         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1441                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1442                                                 GFP_KERNEL);
1443                 if (!cmd->t_task_cdb) {
1444                         pr_err("Unable to allocate cmd->t_task_cdb"
1445                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1446                                 scsi_command_size(cdb),
1447                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1448                         ret = TCM_OUT_OF_RESOURCES;
1449                         goto err;
1450                 }
1451         }
1452         /*
1453          * Copy the original CDB into cmd->
1454          */
1455         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1456
1457         trace_target_sequencer_start(cmd);
1458         return 0;
1459
1460 err:
1461         /*
1462          * Copy the CDB here to allow trace_target_cmd_complete() to
1463          * print the cdb to the trace buffers.
1464          */
1465         memcpy(cmd->t_task_cdb, cdb, min(scsi_command_size(cdb),
1466                                          (unsigned int)TCM_MAX_COMMAND_SIZE));
1467         return ret;
1468 }
1469 EXPORT_SYMBOL(target_cmd_init_cdb);
1470
1471 sense_reason_t
1472 target_cmd_parse_cdb(struct se_cmd *cmd)
1473 {
1474         struct se_device *dev = cmd->se_dev;
1475         sense_reason_t ret;
1476
1477         ret = dev->transport->parse_cdb(cmd);
1478         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1479                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1480                                     cmd->se_tfo->fabric_name,
1481                                     cmd->se_sess->se_node_acl->initiatorname,
1482                                     cmd->t_task_cdb[0]);
1483         if (ret)
1484                 return ret;
1485
1486         ret = transport_check_alloc_task_attr(cmd);
1487         if (ret)
1488                 return ret;
1489
1490         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1491         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1492         return 0;
1493 }
1494 EXPORT_SYMBOL(target_cmd_parse_cdb);
1495
1496 /*
1497  * Used by fabric module frontends to queue tasks directly.
1498  * May only be used from process context.
1499  */
1500 int transport_handle_cdb_direct(
1501         struct se_cmd *cmd)
1502 {
1503         sense_reason_t ret;
1504
1505         if (!cmd->se_lun) {
1506                 dump_stack();
1507                 pr_err("cmd->se_lun is NULL\n");
1508                 return -EINVAL;
1509         }
1510         if (in_interrupt()) {
1511                 dump_stack();
1512                 pr_err("transport_generic_handle_cdb cannot be called"
1513                                 " from interrupt context\n");
1514                 return -EINVAL;
1515         }
1516         /*
1517          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1518          * outstanding descriptors are handled correctly during shutdown via
1519          * transport_wait_for_tasks()
1520          *
1521          * Also, we don't take cmd->t_state_lock here as we only expect
1522          * this to be called for initial descriptor submission.
1523          */
1524         cmd->t_state = TRANSPORT_NEW_CMD;
1525         cmd->transport_state |= CMD_T_ACTIVE;
1526
1527         /*
1528          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1529          * so follow TRANSPORT_NEW_CMD processing thread context usage
1530          * and call transport_generic_request_failure() if necessary..
1531          */
1532         ret = transport_generic_new_cmd(cmd);
1533         if (ret)
1534                 transport_generic_request_failure(cmd, ret);
1535         return 0;
1536 }
1537 EXPORT_SYMBOL(transport_handle_cdb_direct);
1538
1539 sense_reason_t
1540 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1541                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1542 {
1543         if (!sgl || !sgl_count)
1544                 return 0;
1545
1546         /*
1547          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1548          * scatterlists already have been set to follow what the fabric
1549          * passes for the original expected data transfer length.
1550          */
1551         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1552                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1553                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1554                 return TCM_INVALID_CDB_FIELD;
1555         }
1556
1557         cmd->t_data_sg = sgl;
1558         cmd->t_data_nents = sgl_count;
1559         cmd->t_bidi_data_sg = sgl_bidi;
1560         cmd->t_bidi_data_nents = sgl_bidi_count;
1561
1562         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1563         return 0;
1564 }
1565
1566 /**
1567  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1568  *                       se_cmd + use pre-allocated SGL memory.
1569  *
1570  * @se_cmd: command descriptor to submit
1571  * @se_sess: associated se_sess for endpoint
1572  * @cdb: pointer to SCSI CDB
1573  * @sense: pointer to SCSI sense buffer
1574  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1575  * @data_length: fabric expected data transfer length
1576  * @task_attr: SAM task attribute
1577  * @data_dir: DMA data direction
1578  * @flags: flags for command submission from target_sc_flags_tables
1579  * @sgl: struct scatterlist memory for unidirectional mapping
1580  * @sgl_count: scatterlist count for unidirectional mapping
1581  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1582  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1583  * @sgl_prot: struct scatterlist memory protection information
1584  * @sgl_prot_count: scatterlist count for protection information
1585  *
1586  * Task tags are supported if the caller has set @se_cmd->tag.
1587  *
1588  * Returns non zero to signal active I/O shutdown failure.  All other
1589  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1590  * but still return zero here.
1591  *
1592  * This may only be called from process context, and also currently
1593  * assumes internal allocation of fabric payload buffer by target-core.
1594  */
1595 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1596                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1597                 u32 data_length, int task_attr, int data_dir, int flags,
1598                 struct scatterlist *sgl, u32 sgl_count,
1599                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1600                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1601 {
1602         struct se_portal_group *se_tpg;
1603         sense_reason_t rc;
1604         int ret;
1605
1606         se_tpg = se_sess->se_tpg;
1607         BUG_ON(!se_tpg);
1608         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1609         BUG_ON(in_interrupt());
1610         /*
1611          * Initialize se_cmd for target operation.  From this point
1612          * exceptions are handled by sending exception status via
1613          * target_core_fabric_ops->queue_status() callback
1614          */
1615         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1616                                 data_length, data_dir, task_attr, sense,
1617                                 unpacked_lun);
1618
1619         if (flags & TARGET_SCF_USE_CPUID)
1620                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1621         else
1622                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1623
1624         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1625                 se_cmd->unknown_data_length = 1;
1626         /*
1627          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1628          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1629          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1630          * kref_put() to happen during fabric packet acknowledgement.
1631          */
1632         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1633         if (ret)
1634                 return ret;
1635         /*
1636          * Signal bidirectional data payloads to target-core
1637          */
1638         if (flags & TARGET_SCF_BIDI_OP)
1639                 se_cmd->se_cmd_flags |= SCF_BIDI;
1640
1641         rc = target_cmd_init_cdb(se_cmd, cdb);
1642         if (rc) {
1643                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1644                 target_put_sess_cmd(se_cmd);
1645                 return 0;
1646         }
1647
1648         /*
1649          * Locate se_lun pointer and attach it to struct se_cmd
1650          */
1651         rc = transport_lookup_cmd_lun(se_cmd);
1652         if (rc) {
1653                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1654                 target_put_sess_cmd(se_cmd);
1655                 return 0;
1656         }
1657
1658         rc = target_cmd_parse_cdb(se_cmd);
1659         if (rc != 0) {
1660                 transport_generic_request_failure(se_cmd, rc);
1661                 return 0;
1662         }
1663
1664         /*
1665          * Save pointers for SGLs containing protection information,
1666          * if present.
1667          */
1668         if (sgl_prot_count) {
1669                 se_cmd->t_prot_sg = sgl_prot;
1670                 se_cmd->t_prot_nents = sgl_prot_count;
1671                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1672         }
1673
1674         /*
1675          * When a non zero sgl_count has been passed perform SGL passthrough
1676          * mapping for pre-allocated fabric memory instead of having target
1677          * core perform an internal SGL allocation..
1678          */
1679         if (sgl_count != 0) {
1680                 BUG_ON(!sgl);
1681
1682                 /*
1683                  * A work-around for tcm_loop as some userspace code via
1684                  * scsi-generic do not memset their associated read buffers,
1685                  * so go ahead and do that here for type non-data CDBs.  Also
1686                  * note that this is currently guaranteed to be a single SGL
1687                  * for this case by target core in target_setup_cmd_from_cdb()
1688                  * -> transport_generic_cmd_sequencer().
1689                  */
1690                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1691                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1692                         unsigned char *buf = NULL;
1693
1694                         if (sgl)
1695                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1696
1697                         if (buf) {
1698                                 memset(buf, 0, sgl->length);
1699                                 kunmap(sg_page(sgl));
1700                         }
1701                 }
1702
1703                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1704                                 sgl_bidi, sgl_bidi_count);
1705                 if (rc != 0) {
1706                         transport_generic_request_failure(se_cmd, rc);
1707                         return 0;
1708                 }
1709         }
1710
1711         /*
1712          * Check if we need to delay processing because of ALUA
1713          * Active/NonOptimized primary access state..
1714          */
1715         core_alua_check_nonop_delay(se_cmd);
1716
1717         transport_handle_cdb_direct(se_cmd);
1718         return 0;
1719 }
1720 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1721
1722 /**
1723  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1724  *
1725  * @se_cmd: command descriptor to submit
1726  * @se_sess: associated se_sess for endpoint
1727  * @cdb: pointer to SCSI CDB
1728  * @sense: pointer to SCSI sense buffer
1729  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1730  * @data_length: fabric expected data transfer length
1731  * @task_attr: SAM task attribute
1732  * @data_dir: DMA data direction
1733  * @flags: flags for command submission from target_sc_flags_tables
1734  *
1735  * Task tags are supported if the caller has set @se_cmd->tag.
1736  *
1737  * Returns non zero to signal active I/O shutdown failure.  All other
1738  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1739  * but still return zero here.
1740  *
1741  * This may only be called from process context, and also currently
1742  * assumes internal allocation of fabric payload buffer by target-core.
1743  *
1744  * It also assumes interal target core SGL memory allocation.
1745  */
1746 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1747                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1748                 u32 data_length, int task_attr, int data_dir, int flags)
1749 {
1750         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1751                         unpacked_lun, data_length, task_attr, data_dir,
1752                         flags, NULL, 0, NULL, 0, NULL, 0);
1753 }
1754 EXPORT_SYMBOL(target_submit_cmd);
1755
1756 static void target_complete_tmr_failure(struct work_struct *work)
1757 {
1758         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1759
1760         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1761         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1762
1763         transport_lun_remove_cmd(se_cmd);
1764         transport_cmd_check_stop_to_fabric(se_cmd);
1765 }
1766
1767 static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
1768                                        u64 *unpacked_lun)
1769 {
1770         struct se_cmd *se_cmd;
1771         unsigned long flags;
1772         bool ret = false;
1773
1774         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
1775         list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
1776                 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1777                         continue;
1778
1779                 if (se_cmd->tag == tag) {
1780                         *unpacked_lun = se_cmd->orig_fe_lun;
1781                         ret = true;
1782                         break;
1783                 }
1784         }
1785         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
1786
1787         return ret;
1788 }
1789
1790 /**
1791  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1792  *                     for TMR CDBs
1793  *
1794  * @se_cmd: command descriptor to submit
1795  * @se_sess: associated se_sess for endpoint
1796  * @sense: pointer to SCSI sense buffer
1797  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1798  * @fabric_tmr_ptr: fabric context for TMR req
1799  * @tm_type: Type of TM request
1800  * @gfp: gfp type for caller
1801  * @tag: referenced task tag for TMR_ABORT_TASK
1802  * @flags: submit cmd flags
1803  *
1804  * Callable from all contexts.
1805  **/
1806
1807 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1808                 unsigned char *sense, u64 unpacked_lun,
1809                 void *fabric_tmr_ptr, unsigned char tm_type,
1810                 gfp_t gfp, u64 tag, int flags)
1811 {
1812         struct se_portal_group *se_tpg;
1813         int ret;
1814
1815         se_tpg = se_sess->se_tpg;
1816         BUG_ON(!se_tpg);
1817
1818         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1819                               0, DMA_NONE, TCM_SIMPLE_TAG, sense, unpacked_lun);
1820         /*
1821          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1822          * allocation failure.
1823          */
1824         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1825         if (ret < 0)
1826                 return -ENOMEM;
1827
1828         if (tm_type == TMR_ABORT_TASK)
1829                 se_cmd->se_tmr_req->ref_task_tag = tag;
1830
1831         /* See target_submit_cmd for commentary */
1832         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1833         if (ret) {
1834                 core_tmr_release_req(se_cmd->se_tmr_req);
1835                 return ret;
1836         }
1837         /*
1838          * If this is ABORT_TASK with no explicit fabric provided LUN,
1839          * go ahead and search active session tags for a match to figure
1840          * out unpacked_lun for the original se_cmd.
1841          */
1842         if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
1843                 if (!target_lookup_lun_from_tag(se_sess, tag,
1844                                                 &se_cmd->orig_fe_lun))
1845                         goto failure;
1846         }
1847
1848         ret = transport_lookup_tmr_lun(se_cmd);
1849         if (ret)
1850                 goto failure;
1851
1852         transport_generic_handle_tmr(se_cmd);
1853         return 0;
1854
1855         /*
1856          * For callback during failure handling, push this work off
1857          * to process context with TMR_LUN_DOES_NOT_EXIST status.
1858          */
1859 failure:
1860         INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1861         schedule_work(&se_cmd->work);
1862         return 0;
1863 }
1864 EXPORT_SYMBOL(target_submit_tmr);
1865
1866 /*
1867  * Handle SAM-esque emulation for generic transport request failures.
1868  */
1869 void transport_generic_request_failure(struct se_cmd *cmd,
1870                 sense_reason_t sense_reason)
1871 {
1872         int ret = 0, post_ret;
1873
1874         pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
1875                  sense_reason);
1876         target_show_cmd("-----[ ", cmd);
1877
1878         /*
1879          * For SAM Task Attribute emulation for failed struct se_cmd
1880          */
1881         transport_complete_task_attr(cmd);
1882
1883         if (cmd->transport_complete_callback)
1884                 cmd->transport_complete_callback(cmd, false, &post_ret);
1885
1886         if (cmd->transport_state & CMD_T_ABORTED) {
1887                 INIT_WORK(&cmd->work, target_abort_work);
1888                 queue_work(target_completion_wq, &cmd->work);
1889                 return;
1890         }
1891
1892         switch (sense_reason) {
1893         case TCM_NON_EXISTENT_LUN:
1894         case TCM_UNSUPPORTED_SCSI_OPCODE:
1895         case TCM_INVALID_CDB_FIELD:
1896         case TCM_INVALID_PARAMETER_LIST:
1897         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1898         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1899         case TCM_UNKNOWN_MODE_PAGE:
1900         case TCM_WRITE_PROTECTED:
1901         case TCM_ADDRESS_OUT_OF_RANGE:
1902         case TCM_CHECK_CONDITION_ABORT_CMD:
1903         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1904         case TCM_CHECK_CONDITION_NOT_READY:
1905         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1906         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1907         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1908         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1909         case TCM_TOO_MANY_TARGET_DESCS:
1910         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1911         case TCM_TOO_MANY_SEGMENT_DESCS:
1912         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1913                 break;
1914         case TCM_OUT_OF_RESOURCES:
1915                 cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
1916                 goto queue_status;
1917         case TCM_LUN_BUSY:
1918                 cmd->scsi_status = SAM_STAT_BUSY;
1919                 goto queue_status;
1920         case TCM_RESERVATION_CONFLICT:
1921                 /*
1922                  * No SENSE Data payload for this case, set SCSI Status
1923                  * and queue the response to $FABRIC_MOD.
1924                  *
1925                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1926                  */
1927                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1928                 /*
1929                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1930                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1931                  * CONFLICT STATUS.
1932                  *
1933                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1934                  */
1935                 if (cmd->se_sess &&
1936                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl
1937                                         == TARGET_UA_INTLCK_CTRL_ESTABLISH_UA) {
1938                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1939                                                cmd->orig_fe_lun, 0x2C,
1940                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1941                 }
1942
1943                 goto queue_status;
1944         default:
1945                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1946                         cmd->t_task_cdb[0], sense_reason);
1947                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1948                 break;
1949         }
1950
1951         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1952         if (ret)
1953                 goto queue_full;
1954
1955 check_stop:
1956         transport_lun_remove_cmd(cmd);
1957         transport_cmd_check_stop_to_fabric(cmd);
1958         return;
1959
1960 queue_status:
1961         trace_target_cmd_complete(cmd);
1962         ret = cmd->se_tfo->queue_status(cmd);
1963         if (!ret)
1964                 goto check_stop;
1965 queue_full:
1966         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1967 }
1968 EXPORT_SYMBOL(transport_generic_request_failure);
1969
1970 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1971 {
1972         sense_reason_t ret;
1973
1974         if (!cmd->execute_cmd) {
1975                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1976                 goto err;
1977         }
1978         if (do_checks) {
1979                 /*
1980                  * Check for an existing UNIT ATTENTION condition after
1981                  * target_handle_task_attr() has done SAM task attr
1982                  * checking, and possibly have already defered execution
1983                  * out to target_restart_delayed_cmds() context.
1984                  */
1985                 ret = target_scsi3_ua_check(cmd);
1986                 if (ret)
1987                         goto err;
1988
1989                 ret = target_alua_state_check(cmd);
1990                 if (ret)
1991                         goto err;
1992
1993                 ret = target_check_reservation(cmd);
1994                 if (ret) {
1995                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1996                         goto err;
1997                 }
1998         }
1999
2000         ret = cmd->execute_cmd(cmd);
2001         if (!ret)
2002                 return;
2003 err:
2004         spin_lock_irq(&cmd->t_state_lock);
2005         cmd->transport_state &= ~CMD_T_SENT;
2006         spin_unlock_irq(&cmd->t_state_lock);
2007
2008         transport_generic_request_failure(cmd, ret);
2009 }
2010
2011 static int target_write_prot_action(struct se_cmd *cmd)
2012 {
2013         u32 sectors;
2014         /*
2015          * Perform WRITE_INSERT of PI using software emulation when backend
2016          * device has PI enabled, if the transport has not already generated
2017          * PI using hardware WRITE_INSERT offload.
2018          */
2019         switch (cmd->prot_op) {
2020         case TARGET_PROT_DOUT_INSERT:
2021                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
2022                         sbc_dif_generate(cmd);
2023                 break;
2024         case TARGET_PROT_DOUT_STRIP:
2025                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
2026                         break;
2027
2028                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
2029                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2030                                              sectors, 0, cmd->t_prot_sg, 0);
2031                 if (unlikely(cmd->pi_err)) {
2032                         spin_lock_irq(&cmd->t_state_lock);
2033                         cmd->transport_state &= ~CMD_T_SENT;
2034                         spin_unlock_irq(&cmd->t_state_lock);
2035                         transport_generic_request_failure(cmd, cmd->pi_err);
2036                         return -1;
2037                 }
2038                 break;
2039         default:
2040                 break;
2041         }
2042
2043         return 0;
2044 }
2045
2046 static bool target_handle_task_attr(struct se_cmd *cmd)
2047 {
2048         struct se_device *dev = cmd->se_dev;
2049
2050         if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2051                 return false;
2052
2053         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
2054
2055         /*
2056          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
2057          * to allow the passed struct se_cmd list of tasks to the front of the list.
2058          */
2059         switch (cmd->sam_task_attr) {
2060         case TCM_HEAD_TAG:
2061                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
2062                          cmd->t_task_cdb[0]);
2063                 return false;
2064         case TCM_ORDERED_TAG:
2065                 atomic_inc_mb(&dev->dev_ordered_sync);
2066
2067                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
2068                          cmd->t_task_cdb[0]);
2069
2070                 /*
2071                  * Execute an ORDERED command if no other older commands
2072                  * exist that need to be completed first.
2073                  */
2074                 if (!atomic_read(&dev->simple_cmds))
2075                         return false;
2076                 break;
2077         default:
2078                 /*
2079                  * For SIMPLE and UNTAGGED Task Attribute commands
2080                  */
2081                 atomic_inc_mb(&dev->simple_cmds);
2082                 break;
2083         }
2084
2085         if (atomic_read(&dev->dev_ordered_sync) == 0)
2086                 return false;
2087
2088         spin_lock(&dev->delayed_cmd_lock);
2089         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
2090         spin_unlock(&dev->delayed_cmd_lock);
2091
2092         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
2093                 cmd->t_task_cdb[0], cmd->sam_task_attr);
2094         return true;
2095 }
2096
2097 void target_execute_cmd(struct se_cmd *cmd)
2098 {
2099         /*
2100          * Determine if frontend context caller is requesting the stopping of
2101          * this command for frontend exceptions.
2102          *
2103          * If the received CDB has already been aborted stop processing it here.
2104          */
2105         if (target_cmd_interrupted(cmd))
2106                 return;
2107
2108         spin_lock_irq(&cmd->t_state_lock);
2109         cmd->t_state = TRANSPORT_PROCESSING;
2110         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
2111         spin_unlock_irq(&cmd->t_state_lock);
2112
2113         if (target_write_prot_action(cmd))
2114                 return;
2115
2116         if (target_handle_task_attr(cmd)) {
2117                 spin_lock_irq(&cmd->t_state_lock);
2118                 cmd->transport_state &= ~CMD_T_SENT;
2119                 spin_unlock_irq(&cmd->t_state_lock);
2120                 return;
2121         }
2122
2123         __target_execute_cmd(cmd, true);
2124 }
2125 EXPORT_SYMBOL(target_execute_cmd);
2126
2127 /*
2128  * Process all commands up to the last received ORDERED task attribute which
2129  * requires another blocking boundary
2130  */
2131 static void target_restart_delayed_cmds(struct se_device *dev)
2132 {
2133         for (;;) {
2134                 struct se_cmd *cmd;
2135
2136                 spin_lock(&dev->delayed_cmd_lock);
2137                 if (list_empty(&dev->delayed_cmd_list)) {
2138                         spin_unlock(&dev->delayed_cmd_lock);
2139                         break;
2140                 }
2141
2142                 cmd = list_entry(dev->delayed_cmd_list.next,
2143                                  struct se_cmd, se_delayed_node);
2144                 list_del(&cmd->se_delayed_node);
2145                 spin_unlock(&dev->delayed_cmd_lock);
2146
2147                 cmd->transport_state |= CMD_T_SENT;
2148
2149                 __target_execute_cmd(cmd, true);
2150
2151                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
2152                         break;
2153         }
2154 }
2155
2156 /*
2157  * Called from I/O completion to determine which dormant/delayed
2158  * and ordered cmds need to have their tasks added to the execution queue.
2159  */
2160 static void transport_complete_task_attr(struct se_cmd *cmd)
2161 {
2162         struct se_device *dev = cmd->se_dev;
2163
2164         if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2165                 return;
2166
2167         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2168                 goto restart;
2169
2170         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2171                 atomic_dec_mb(&dev->simple_cmds);
2172                 dev->dev_cur_ordered_id++;
2173         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2174                 dev->dev_cur_ordered_id++;
2175                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2176                          dev->dev_cur_ordered_id);
2177         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2178                 atomic_dec_mb(&dev->dev_ordered_sync);
2179
2180                 dev->dev_cur_ordered_id++;
2181                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2182                          dev->dev_cur_ordered_id);
2183         }
2184         cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2185
2186 restart:
2187         target_restart_delayed_cmds(dev);
2188 }
2189
2190 static void transport_complete_qf(struct se_cmd *cmd)
2191 {
2192         int ret = 0;
2193
2194         transport_complete_task_attr(cmd);
2195         /*
2196          * If a fabric driver ->write_pending() or ->queue_data_in() callback
2197          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2198          * the same callbacks should not be retried.  Return CHECK_CONDITION
2199          * if a scsi_status is not already set.
2200          *
2201          * If a fabric driver ->queue_status() has returned non zero, always
2202          * keep retrying no matter what..
2203          */
2204         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2205                 if (cmd->scsi_status)
2206                         goto queue_status;
2207
2208                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2209                 goto queue_status;
2210         }
2211
2212         /*
2213          * Check if we need to send a sense buffer from
2214          * the struct se_cmd in question. We do NOT want
2215          * to take this path of the IO has been marked as
2216          * needing to be treated like a "normal read". This
2217          * is the case if it's a tape read, and either the
2218          * FM, EOM, or ILI bits are set, but there is no
2219          * sense data.
2220          */
2221         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2222             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2223                 goto queue_status;
2224
2225         switch (cmd->data_direction) {
2226         case DMA_FROM_DEVICE:
2227                 /* queue status if not treating this as a normal read */
2228                 if (cmd->scsi_status &&
2229                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2230                         goto queue_status;
2231
2232                 trace_target_cmd_complete(cmd);
2233                 ret = cmd->se_tfo->queue_data_in(cmd);
2234                 break;
2235         case DMA_TO_DEVICE:
2236                 if (cmd->se_cmd_flags & SCF_BIDI) {
2237                         ret = cmd->se_tfo->queue_data_in(cmd);
2238                         break;
2239                 }
2240                 fallthrough;
2241         case DMA_NONE:
2242 queue_status:
2243                 trace_target_cmd_complete(cmd);
2244                 ret = cmd->se_tfo->queue_status(cmd);
2245                 break;
2246         default:
2247                 break;
2248         }
2249
2250         if (ret < 0) {
2251                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2252                 return;
2253         }
2254         transport_lun_remove_cmd(cmd);
2255         transport_cmd_check_stop_to_fabric(cmd);
2256 }
2257
2258 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2259                                         int err, bool write_pending)
2260 {
2261         /*
2262          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2263          * ->queue_data_in() callbacks from new process context.
2264          *
2265          * Otherwise for other errors, transport_complete_qf() will send
2266          * CHECK_CONDITION via ->queue_status() instead of attempting to
2267          * retry associated fabric driver data-transfer callbacks.
2268          */
2269         if (err == -EAGAIN || err == -ENOMEM) {
2270                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2271                                                  TRANSPORT_COMPLETE_QF_OK;
2272         } else {
2273                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2274                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2275         }
2276
2277         spin_lock_irq(&dev->qf_cmd_lock);
2278         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2279         atomic_inc_mb(&dev->dev_qf_count);
2280         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2281
2282         schedule_work(&cmd->se_dev->qf_work_queue);
2283 }
2284
2285 static bool target_read_prot_action(struct se_cmd *cmd)
2286 {
2287         switch (cmd->prot_op) {
2288         case TARGET_PROT_DIN_STRIP:
2289                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2290                         u32 sectors = cmd->data_length >>
2291                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2292
2293                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2294                                                      sectors, 0, cmd->t_prot_sg,
2295                                                      0);
2296                         if (cmd->pi_err)
2297                                 return true;
2298                 }
2299                 break;
2300         case TARGET_PROT_DIN_INSERT:
2301                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2302                         break;
2303
2304                 sbc_dif_generate(cmd);
2305                 break;
2306         default:
2307                 break;
2308         }
2309
2310         return false;
2311 }
2312
2313 static void target_complete_ok_work(struct work_struct *work)
2314 {
2315         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2316         int ret;
2317
2318         /*
2319          * Check if we need to move delayed/dormant tasks from cmds on the
2320          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2321          * Attribute.
2322          */
2323         transport_complete_task_attr(cmd);
2324
2325         /*
2326          * Check to schedule QUEUE_FULL work, or execute an existing
2327          * cmd->transport_qf_callback()
2328          */
2329         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2330                 schedule_work(&cmd->se_dev->qf_work_queue);
2331
2332         /*
2333          * Check if we need to send a sense buffer from
2334          * the struct se_cmd in question. We do NOT want
2335          * to take this path of the IO has been marked as
2336          * needing to be treated like a "normal read". This
2337          * is the case if it's a tape read, and either the
2338          * FM, EOM, or ILI bits are set, but there is no
2339          * sense data.
2340          */
2341         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2342             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2343                 WARN_ON(!cmd->scsi_status);
2344                 ret = transport_send_check_condition_and_sense(
2345                                         cmd, 0, 1);
2346                 if (ret)
2347                         goto queue_full;
2348
2349                 transport_lun_remove_cmd(cmd);
2350                 transport_cmd_check_stop_to_fabric(cmd);
2351                 return;
2352         }
2353         /*
2354          * Check for a callback, used by amongst other things
2355          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2356          */
2357         if (cmd->transport_complete_callback) {
2358                 sense_reason_t rc;
2359                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2360                 bool zero_dl = !(cmd->data_length);
2361                 int post_ret = 0;
2362
2363                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2364                 if (!rc && !post_ret) {
2365                         if (caw && zero_dl)
2366                                 goto queue_rsp;
2367
2368                         return;
2369                 } else if (rc) {
2370                         ret = transport_send_check_condition_and_sense(cmd,
2371                                                 rc, 0);
2372                         if (ret)
2373                                 goto queue_full;
2374
2375                         transport_lun_remove_cmd(cmd);
2376                         transport_cmd_check_stop_to_fabric(cmd);
2377                         return;
2378                 }
2379         }
2380
2381 queue_rsp:
2382         switch (cmd->data_direction) {
2383         case DMA_FROM_DEVICE:
2384                 /*
2385                  * if this is a READ-type IO, but SCSI status
2386                  * is set, then skip returning data and just
2387                  * return the status -- unless this IO is marked
2388                  * as needing to be treated as a normal read,
2389                  * in which case we want to go ahead and return
2390                  * the data. This happens, for example, for tape
2391                  * reads with the FM, EOM, or ILI bits set, with
2392                  * no sense data.
2393                  */
2394                 if (cmd->scsi_status &&
2395                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2396                         goto queue_status;
2397
2398                 atomic_long_add(cmd->data_length,
2399                                 &cmd->se_lun->lun_stats.tx_data_octets);
2400                 /*
2401                  * Perform READ_STRIP of PI using software emulation when
2402                  * backend had PI enabled, if the transport will not be
2403                  * performing hardware READ_STRIP offload.
2404                  */
2405                 if (target_read_prot_action(cmd)) {
2406                         ret = transport_send_check_condition_and_sense(cmd,
2407                                                 cmd->pi_err, 0);
2408                         if (ret)
2409                                 goto queue_full;
2410
2411                         transport_lun_remove_cmd(cmd);
2412                         transport_cmd_check_stop_to_fabric(cmd);
2413                         return;
2414                 }
2415
2416                 trace_target_cmd_complete(cmd);
2417                 ret = cmd->se_tfo->queue_data_in(cmd);
2418                 if (ret)
2419                         goto queue_full;
2420                 break;
2421         case DMA_TO_DEVICE:
2422                 atomic_long_add(cmd->data_length,
2423                                 &cmd->se_lun->lun_stats.rx_data_octets);
2424                 /*
2425                  * Check if we need to send READ payload for BIDI-COMMAND
2426                  */
2427                 if (cmd->se_cmd_flags & SCF_BIDI) {
2428                         atomic_long_add(cmd->data_length,
2429                                         &cmd->se_lun->lun_stats.tx_data_octets);
2430                         ret = cmd->se_tfo->queue_data_in(cmd);
2431                         if (ret)
2432                                 goto queue_full;
2433                         break;
2434                 }
2435                 fallthrough;
2436         case DMA_NONE:
2437 queue_status:
2438                 trace_target_cmd_complete(cmd);
2439                 ret = cmd->se_tfo->queue_status(cmd);
2440                 if (ret)
2441                         goto queue_full;
2442                 break;
2443         default:
2444                 break;
2445         }
2446
2447         transport_lun_remove_cmd(cmd);
2448         transport_cmd_check_stop_to_fabric(cmd);
2449         return;
2450
2451 queue_full:
2452         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2453                 " data_direction: %d\n", cmd, cmd->data_direction);
2454
2455         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2456 }
2457
2458 void target_free_sgl(struct scatterlist *sgl, int nents)
2459 {
2460         sgl_free_n_order(sgl, nents, 0);
2461 }
2462 EXPORT_SYMBOL(target_free_sgl);
2463
2464 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2465 {
2466         /*
2467          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2468          * emulation, and free + reset pointers if necessary..
2469          */
2470         if (!cmd->t_data_sg_orig)
2471                 return;
2472
2473         kfree(cmd->t_data_sg);
2474         cmd->t_data_sg = cmd->t_data_sg_orig;
2475         cmd->t_data_sg_orig = NULL;
2476         cmd->t_data_nents = cmd->t_data_nents_orig;
2477         cmd->t_data_nents_orig = 0;
2478 }
2479
2480 static inline void transport_free_pages(struct se_cmd *cmd)
2481 {
2482         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2483                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2484                 cmd->t_prot_sg = NULL;
2485                 cmd->t_prot_nents = 0;
2486         }
2487
2488         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2489                 /*
2490                  * Release special case READ buffer payload required for
2491                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2492                  */
2493                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2494                         target_free_sgl(cmd->t_bidi_data_sg,
2495                                            cmd->t_bidi_data_nents);
2496                         cmd->t_bidi_data_sg = NULL;
2497                         cmd->t_bidi_data_nents = 0;
2498                 }
2499                 transport_reset_sgl_orig(cmd);
2500                 return;
2501         }
2502         transport_reset_sgl_orig(cmd);
2503
2504         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2505         cmd->t_data_sg = NULL;
2506         cmd->t_data_nents = 0;
2507
2508         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2509         cmd->t_bidi_data_sg = NULL;
2510         cmd->t_bidi_data_nents = 0;
2511 }
2512
2513 void *transport_kmap_data_sg(struct se_cmd *cmd)
2514 {
2515         struct scatterlist *sg = cmd->t_data_sg;
2516         struct page **pages;
2517         int i;
2518
2519         /*
2520          * We need to take into account a possible offset here for fabrics like
2521          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2522          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2523          */
2524         if (!cmd->t_data_nents)
2525                 return NULL;
2526
2527         BUG_ON(!sg);
2528         if (cmd->t_data_nents == 1)
2529                 return kmap(sg_page(sg)) + sg->offset;
2530
2531         /* >1 page. use vmap */
2532         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2533         if (!pages)
2534                 return NULL;
2535
2536         /* convert sg[] to pages[] */
2537         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2538                 pages[i] = sg_page(sg);
2539         }
2540
2541         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2542         kfree(pages);
2543         if (!cmd->t_data_vmap)
2544                 return NULL;
2545
2546         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2547 }
2548 EXPORT_SYMBOL(transport_kmap_data_sg);
2549
2550 void transport_kunmap_data_sg(struct se_cmd *cmd)
2551 {
2552         if (!cmd->t_data_nents) {
2553                 return;
2554         } else if (cmd->t_data_nents == 1) {
2555                 kunmap(sg_page(cmd->t_data_sg));
2556                 return;
2557         }
2558
2559         vunmap(cmd->t_data_vmap);
2560         cmd->t_data_vmap = NULL;
2561 }
2562 EXPORT_SYMBOL(transport_kunmap_data_sg);
2563
2564 int
2565 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2566                  bool zero_page, bool chainable)
2567 {
2568         gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
2569
2570         *sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
2571         return *sgl ? 0 : -ENOMEM;
2572 }
2573 EXPORT_SYMBOL(target_alloc_sgl);
2574
2575 /*
2576  * Allocate any required resources to execute the command.  For writes we
2577  * might not have the payload yet, so notify the fabric via a call to
2578  * ->write_pending instead. Otherwise place it on the execution queue.
2579  */
2580 sense_reason_t
2581 transport_generic_new_cmd(struct se_cmd *cmd)
2582 {
2583         unsigned long flags;
2584         int ret = 0;
2585         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2586
2587         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2588             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2589                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2590                                        cmd->prot_length, true, false);
2591                 if (ret < 0)
2592                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2593         }
2594
2595         /*
2596          * Determine if the TCM fabric module has already allocated physical
2597          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2598          * beforehand.
2599          */
2600         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2601             cmd->data_length) {
2602
2603                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2604                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2605                         u32 bidi_length;
2606
2607                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2608                                 bidi_length = cmd->t_task_nolb *
2609                                               cmd->se_dev->dev_attrib.block_size;
2610                         else
2611                                 bidi_length = cmd->data_length;
2612
2613                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2614                                                &cmd->t_bidi_data_nents,
2615                                                bidi_length, zero_flag, false);
2616                         if (ret < 0)
2617                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2618                 }
2619
2620                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2621                                        cmd->data_length, zero_flag, false);
2622                 if (ret < 0)
2623                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2624         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2625                     cmd->data_length) {
2626                 /*
2627                  * Special case for COMPARE_AND_WRITE with fabrics
2628                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2629                  */
2630                 u32 caw_length = cmd->t_task_nolb *
2631                                  cmd->se_dev->dev_attrib.block_size;
2632
2633                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2634                                        &cmd->t_bidi_data_nents,
2635                                        caw_length, zero_flag, false);
2636                 if (ret < 0)
2637                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2638         }
2639         /*
2640          * If this command is not a write we can execute it right here,
2641          * for write buffers we need to notify the fabric driver first
2642          * and let it call back once the write buffers are ready.
2643          */
2644         target_add_to_state_list(cmd);
2645         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2646                 target_execute_cmd(cmd);
2647                 return 0;
2648         }
2649
2650         spin_lock_irqsave(&cmd->t_state_lock, flags);
2651         cmd->t_state = TRANSPORT_WRITE_PENDING;
2652         /*
2653          * Determine if frontend context caller is requesting the stopping of
2654          * this command for frontend exceptions.
2655          */
2656         if (cmd->transport_state & CMD_T_STOP &&
2657             !cmd->se_tfo->write_pending_must_be_called) {
2658                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2659                          __func__, __LINE__, cmd->tag);
2660
2661                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2662
2663                 complete_all(&cmd->t_transport_stop_comp);
2664                 return 0;
2665         }
2666         cmd->transport_state &= ~CMD_T_ACTIVE;
2667         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2668
2669         ret = cmd->se_tfo->write_pending(cmd);
2670         if (ret)
2671                 goto queue_full;
2672
2673         return 0;
2674
2675 queue_full:
2676         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2677         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2678         return 0;
2679 }
2680 EXPORT_SYMBOL(transport_generic_new_cmd);
2681
2682 static void transport_write_pending_qf(struct se_cmd *cmd)
2683 {
2684         unsigned long flags;
2685         int ret;
2686         bool stop;
2687
2688         spin_lock_irqsave(&cmd->t_state_lock, flags);
2689         stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2690         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2691
2692         if (stop) {
2693                 pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2694                         __func__, __LINE__, cmd->tag);
2695                 complete_all(&cmd->t_transport_stop_comp);
2696                 return;
2697         }
2698
2699         ret = cmd->se_tfo->write_pending(cmd);
2700         if (ret) {
2701                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2702                          cmd);
2703                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2704         }
2705 }
2706
2707 static bool
2708 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2709                            unsigned long *flags);
2710
2711 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2712 {
2713         unsigned long flags;
2714
2715         spin_lock_irqsave(&cmd->t_state_lock, flags);
2716         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2717         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2718 }
2719
2720 /*
2721  * Call target_put_sess_cmd() and wait until target_release_cmd_kref(@cmd) has
2722  * finished.
2723  */
2724 void target_put_cmd_and_wait(struct se_cmd *cmd)
2725 {
2726         DECLARE_COMPLETION_ONSTACK(compl);
2727
2728         WARN_ON_ONCE(cmd->abrt_compl);
2729         cmd->abrt_compl = &compl;
2730         target_put_sess_cmd(cmd);
2731         wait_for_completion(&compl);
2732 }
2733
2734 /*
2735  * This function is called by frontend drivers after processing of a command
2736  * has finished.
2737  *
2738  * The protocol for ensuring that either the regular frontend command
2739  * processing flow or target_handle_abort() code drops one reference is as
2740  * follows:
2741  * - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
2742  *   the frontend driver to call this function synchronously or asynchronously.
2743  *   That will cause one reference to be dropped.
2744  * - During regular command processing the target core sets CMD_T_COMPLETE
2745  *   before invoking one of the .queue_*() functions.
2746  * - The code that aborts commands skips commands and TMFs for which
2747  *   CMD_T_COMPLETE has been set.
2748  * - CMD_T_ABORTED is set atomically after the CMD_T_COMPLETE check for
2749  *   commands that will be aborted.
2750  * - If the CMD_T_ABORTED flag is set but CMD_T_TAS has not been set
2751  *   transport_generic_free_cmd() skips its call to target_put_sess_cmd().
2752  * - For aborted commands for which CMD_T_TAS has been set .queue_status() will
2753  *   be called and will drop a reference.
2754  * - For aborted commands for which CMD_T_TAS has not been set .aborted_task()
2755  *   will be called. target_handle_abort() will drop the final reference.
2756  */
2757 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2758 {
2759         DECLARE_COMPLETION_ONSTACK(compl);
2760         int ret = 0;
2761         bool aborted = false, tas = false;
2762
2763         if (wait_for_tasks)
2764                 target_wait_free_cmd(cmd, &aborted, &tas);
2765
2766         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD) {
2767                 /*
2768                  * Handle WRITE failure case where transport_generic_new_cmd()
2769                  * has already added se_cmd to state_list, but fabric has
2770                  * failed command before I/O submission.
2771                  */
2772                 if (cmd->state_active)
2773                         target_remove_from_state_list(cmd);
2774
2775                 if (cmd->se_lun)
2776                         transport_lun_remove_cmd(cmd);
2777         }
2778         if (aborted)
2779                 cmd->free_compl = &compl;
2780         ret = target_put_sess_cmd(cmd);
2781         if (aborted) {
2782                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2783                 wait_for_completion(&compl);
2784                 ret = 1;
2785         }
2786         return ret;
2787 }
2788 EXPORT_SYMBOL(transport_generic_free_cmd);
2789
2790 /**
2791  * target_get_sess_cmd - Add command to active ->sess_cmd_list
2792  * @se_cmd:     command descriptor to add
2793  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2794  */
2795 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2796 {
2797         struct se_session *se_sess = se_cmd->se_sess;
2798         unsigned long flags;
2799         int ret = 0;
2800
2801         /*
2802          * Add a second kref if the fabric caller is expecting to handle
2803          * fabric acknowledgement that requires two target_put_sess_cmd()
2804          * invocations before se_cmd descriptor release.
2805          */
2806         if (ack_kref) {
2807                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2808                         return -EINVAL;
2809
2810                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2811         }
2812
2813         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2814         if (se_sess->sess_tearing_down) {
2815                 ret = -ESHUTDOWN;
2816                 goto out;
2817         }
2818         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2819         percpu_ref_get(&se_sess->cmd_count);
2820 out:
2821         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2822
2823         if (ret && ack_kref)
2824                 target_put_sess_cmd(se_cmd);
2825
2826         return ret;
2827 }
2828 EXPORT_SYMBOL(target_get_sess_cmd);
2829
2830 static void target_free_cmd_mem(struct se_cmd *cmd)
2831 {
2832         transport_free_pages(cmd);
2833
2834         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2835                 core_tmr_release_req(cmd->se_tmr_req);
2836         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2837                 kfree(cmd->t_task_cdb);
2838 }
2839
2840 static void target_release_cmd_kref(struct kref *kref)
2841 {
2842         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2843         struct se_session *se_sess = se_cmd->se_sess;
2844         struct completion *free_compl = se_cmd->free_compl;
2845         struct completion *abrt_compl = se_cmd->abrt_compl;
2846         unsigned long flags;
2847
2848         if (se_sess) {
2849                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2850                 list_del_init(&se_cmd->se_cmd_list);
2851                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2852         }
2853
2854         target_free_cmd_mem(se_cmd);
2855         se_cmd->se_tfo->release_cmd(se_cmd);
2856         if (free_compl)
2857                 complete(free_compl);
2858         if (abrt_compl)
2859                 complete(abrt_compl);
2860
2861         percpu_ref_put(&se_sess->cmd_count);
2862 }
2863
2864 /**
2865  * target_put_sess_cmd - decrease the command reference count
2866  * @se_cmd:     command to drop a reference from
2867  *
2868  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2869  * refcount to drop to zero. Returns zero otherwise.
2870  */
2871 int target_put_sess_cmd(struct se_cmd *se_cmd)
2872 {
2873         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2874 }
2875 EXPORT_SYMBOL(target_put_sess_cmd);
2876
2877 static const char *data_dir_name(enum dma_data_direction d)
2878 {
2879         switch (d) {
2880         case DMA_BIDIRECTIONAL: return "BIDI";
2881         case DMA_TO_DEVICE:     return "WRITE";
2882         case DMA_FROM_DEVICE:   return "READ";
2883         case DMA_NONE:          return "NONE";
2884         }
2885
2886         return "(?)";
2887 }
2888
2889 static const char *cmd_state_name(enum transport_state_table t)
2890 {
2891         switch (t) {
2892         case TRANSPORT_NO_STATE:        return "NO_STATE";
2893         case TRANSPORT_NEW_CMD:         return "NEW_CMD";
2894         case TRANSPORT_WRITE_PENDING:   return "WRITE_PENDING";
2895         case TRANSPORT_PROCESSING:      return "PROCESSING";
2896         case TRANSPORT_COMPLETE:        return "COMPLETE";
2897         case TRANSPORT_ISTATE_PROCESSING:
2898                                         return "ISTATE_PROCESSING";
2899         case TRANSPORT_COMPLETE_QF_WP:  return "COMPLETE_QF_WP";
2900         case TRANSPORT_COMPLETE_QF_OK:  return "COMPLETE_QF_OK";
2901         case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
2902         }
2903
2904         return "(?)";
2905 }
2906
2907 static void target_append_str(char **str, const char *txt)
2908 {
2909         char *prev = *str;
2910
2911         *str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
2912                 kstrdup(txt, GFP_ATOMIC);
2913         kfree(prev);
2914 }
2915
2916 /*
2917  * Convert a transport state bitmask into a string. The caller is
2918  * responsible for freeing the returned pointer.
2919  */
2920 static char *target_ts_to_str(u32 ts)
2921 {
2922         char *str = NULL;
2923
2924         if (ts & CMD_T_ABORTED)
2925                 target_append_str(&str, "aborted");
2926         if (ts & CMD_T_ACTIVE)
2927                 target_append_str(&str, "active");
2928         if (ts & CMD_T_COMPLETE)
2929                 target_append_str(&str, "complete");
2930         if (ts & CMD_T_SENT)
2931                 target_append_str(&str, "sent");
2932         if (ts & CMD_T_STOP)
2933                 target_append_str(&str, "stop");
2934         if (ts & CMD_T_FABRIC_STOP)
2935                 target_append_str(&str, "fabric_stop");
2936
2937         return str;
2938 }
2939
2940 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
2941 {
2942         switch (tmf) {
2943         case TMR_ABORT_TASK:            return "ABORT_TASK";
2944         case TMR_ABORT_TASK_SET:        return "ABORT_TASK_SET";
2945         case TMR_CLEAR_ACA:             return "CLEAR_ACA";
2946         case TMR_CLEAR_TASK_SET:        return "CLEAR_TASK_SET";
2947         case TMR_LUN_RESET:             return "LUN_RESET";
2948         case TMR_TARGET_WARM_RESET:     return "TARGET_WARM_RESET";
2949         case TMR_TARGET_COLD_RESET:     return "TARGET_COLD_RESET";
2950         case TMR_LUN_RESET_PRO:         return "LUN_RESET_PRO";
2951         case TMR_UNKNOWN:               break;
2952         }
2953         return "(?)";
2954 }
2955
2956 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
2957 {
2958         char *ts_str = target_ts_to_str(cmd->transport_state);
2959         const u8 *cdb = cmd->t_task_cdb;
2960         struct se_tmr_req *tmf = cmd->se_tmr_req;
2961
2962         if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2963                 pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
2964                          pfx, cdb[0], cdb[1], cmd->tag,
2965                          data_dir_name(cmd->data_direction),
2966                          cmd->se_tfo->get_cmd_state(cmd),
2967                          cmd_state_name(cmd->t_state), cmd->data_length,
2968                          kref_read(&cmd->cmd_kref), ts_str);
2969         } else {
2970                 pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
2971                          pfx, target_tmf_name(tmf->function), cmd->tag,
2972                          tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
2973                          cmd_state_name(cmd->t_state),
2974                          kref_read(&cmd->cmd_kref), ts_str);
2975         }
2976         kfree(ts_str);
2977 }
2978 EXPORT_SYMBOL(target_show_cmd);
2979
2980 /**
2981  * target_sess_cmd_list_set_waiting - Set sess_tearing_down so no new commands are queued.
2982  * @se_sess:    session to flag
2983  */
2984 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2985 {
2986         unsigned long flags;
2987
2988         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2989         se_sess->sess_tearing_down = 1;
2990         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2991
2992         percpu_ref_kill(&se_sess->cmd_count);
2993 }
2994 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2995
2996 /**
2997  * target_wait_for_sess_cmds - Wait for outstanding commands
2998  * @se_sess:    session to wait for active I/O
2999  */
3000 void target_wait_for_sess_cmds(struct se_session *se_sess)
3001 {
3002         struct se_cmd *cmd;
3003         int ret;
3004
3005         WARN_ON_ONCE(!se_sess->sess_tearing_down);
3006
3007         do {
3008                 ret = wait_event_timeout(se_sess->cmd_list_wq,
3009                                 percpu_ref_is_zero(&se_sess->cmd_count),
3010                                 180 * HZ);
3011                 list_for_each_entry(cmd, &se_sess->sess_cmd_list, se_cmd_list)
3012                         target_show_cmd("session shutdown: still waiting for ",
3013                                         cmd);
3014         } while (ret <= 0);
3015 }
3016 EXPORT_SYMBOL(target_wait_for_sess_cmds);
3017
3018 /*
3019  * Prevent that new percpu_ref_tryget_live() calls succeed and wait until
3020  * all references to the LUN have been released. Called during LUN shutdown.
3021  */
3022 void transport_clear_lun_ref(struct se_lun *lun)
3023 {
3024         percpu_ref_kill(&lun->lun_ref);
3025         wait_for_completion(&lun->lun_shutdown_comp);
3026 }
3027
3028 static bool
3029 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
3030                            bool *aborted, bool *tas, unsigned long *flags)
3031         __releases(&cmd->t_state_lock)
3032         __acquires(&cmd->t_state_lock)
3033 {
3034
3035         assert_spin_locked(&cmd->t_state_lock);
3036         WARN_ON_ONCE(!irqs_disabled());
3037
3038         if (fabric_stop)
3039                 cmd->transport_state |= CMD_T_FABRIC_STOP;
3040
3041         if (cmd->transport_state & CMD_T_ABORTED)
3042                 *aborted = true;
3043
3044         if (cmd->transport_state & CMD_T_TAS)
3045                 *tas = true;
3046
3047         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
3048             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3049                 return false;
3050
3051         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
3052             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3053                 return false;
3054
3055         if (!(cmd->transport_state & CMD_T_ACTIVE))
3056                 return false;
3057
3058         if (fabric_stop && *aborted)
3059                 return false;
3060
3061         cmd->transport_state |= CMD_T_STOP;
3062
3063         target_show_cmd("wait_for_tasks: Stopping ", cmd);
3064
3065         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
3066
3067         while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
3068                                             180 * HZ))
3069                 target_show_cmd("wait for tasks: ", cmd);
3070
3071         spin_lock_irqsave(&cmd->t_state_lock, *flags);
3072         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
3073
3074         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
3075                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
3076
3077         return true;
3078 }
3079
3080 /**
3081  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3082  * @cmd: command to wait on
3083  */
3084 bool transport_wait_for_tasks(struct se_cmd *cmd)
3085 {
3086         unsigned long flags;
3087         bool ret, aborted = false, tas = false;
3088
3089         spin_lock_irqsave(&cmd->t_state_lock, flags);
3090         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3091         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3092
3093         return ret;
3094 }
3095 EXPORT_SYMBOL(transport_wait_for_tasks);
3096
3097 struct sense_info {
3098         u8 key;
3099         u8 asc;
3100         u8 ascq;
3101         bool add_sector_info;
3102 };
3103
3104 static const struct sense_info sense_info_table[] = {
3105         [TCM_NO_SENSE] = {
3106                 .key = NOT_READY
3107         },
3108         [TCM_NON_EXISTENT_LUN] = {
3109                 .key = ILLEGAL_REQUEST,
3110                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3111         },
3112         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
3113                 .key = ILLEGAL_REQUEST,
3114                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3115         },
3116         [TCM_SECTOR_COUNT_TOO_MANY] = {
3117                 .key = ILLEGAL_REQUEST,
3118                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3119         },
3120         [TCM_UNKNOWN_MODE_PAGE] = {
3121                 .key = ILLEGAL_REQUEST,
3122                 .asc = 0x24, /* INVALID FIELD IN CDB */
3123         },
3124         [TCM_CHECK_CONDITION_ABORT_CMD] = {
3125                 .key = ABORTED_COMMAND,
3126                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3127                 .ascq = 0x03,
3128         },
3129         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
3130                 .key = ABORTED_COMMAND,
3131                 .asc = 0x0c, /* WRITE ERROR */
3132                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3133         },
3134         [TCM_INVALID_CDB_FIELD] = {
3135                 .key = ILLEGAL_REQUEST,
3136                 .asc = 0x24, /* INVALID FIELD IN CDB */
3137         },
3138         [TCM_INVALID_PARAMETER_LIST] = {
3139                 .key = ILLEGAL_REQUEST,
3140                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3141         },
3142         [TCM_TOO_MANY_TARGET_DESCS] = {
3143                 .key = ILLEGAL_REQUEST,
3144                 .asc = 0x26,
3145                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3146         },
3147         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3148                 .key = ILLEGAL_REQUEST,
3149                 .asc = 0x26,
3150                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3151         },
3152         [TCM_TOO_MANY_SEGMENT_DESCS] = {
3153                 .key = ILLEGAL_REQUEST,
3154                 .asc = 0x26,
3155                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3156         },
3157         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3158                 .key = ILLEGAL_REQUEST,
3159                 .asc = 0x26,
3160                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3161         },
3162         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3163                 .key = ILLEGAL_REQUEST,
3164                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3165         },
3166         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3167                 .key = ILLEGAL_REQUEST,
3168                 .asc = 0x0c, /* WRITE ERROR */
3169                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3170         },
3171         [TCM_SERVICE_CRC_ERROR] = {
3172                 .key = ABORTED_COMMAND,
3173                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3174                 .ascq = 0x05, /* N/A */
3175         },
3176         [TCM_SNACK_REJECTED] = {
3177                 .key = ABORTED_COMMAND,
3178                 .asc = 0x11, /* READ ERROR */
3179                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3180         },
3181         [TCM_WRITE_PROTECTED] = {
3182                 .key = DATA_PROTECT,
3183                 .asc = 0x27, /* WRITE PROTECTED */
3184         },
3185         [TCM_ADDRESS_OUT_OF_RANGE] = {
3186                 .key = ILLEGAL_REQUEST,
3187                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3188         },
3189         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3190                 .key = UNIT_ATTENTION,
3191         },
3192         [TCM_CHECK_CONDITION_NOT_READY] = {
3193                 .key = NOT_READY,
3194         },
3195         [TCM_MISCOMPARE_VERIFY] = {
3196                 .key = MISCOMPARE,
3197                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3198                 .ascq = 0x00,
3199         },
3200         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3201                 .key = ABORTED_COMMAND,
3202                 .asc = 0x10,
3203                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3204                 .add_sector_info = true,
3205         },
3206         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3207                 .key = ABORTED_COMMAND,
3208                 .asc = 0x10,
3209                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3210                 .add_sector_info = true,
3211         },
3212         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3213                 .key = ABORTED_COMMAND,
3214                 .asc = 0x10,
3215                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3216                 .add_sector_info = true,
3217         },
3218         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3219                 .key = COPY_ABORTED,
3220                 .asc = 0x0d,
3221                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3222
3223         },
3224         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3225                 /*
3226                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
3227                  * Solaris initiators.  Returning NOT READY instead means the
3228                  * operations will be retried a finite number of times and we
3229                  * can survive intermittent errors.
3230                  */
3231                 .key = NOT_READY,
3232                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3233         },
3234         [TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3235                 /*
3236                  * From spc4r22 section5.7.7,5.7.8
3237                  * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3238                  * or a REGISTER AND IGNORE EXISTING KEY service action or
3239                  * REGISTER AND MOVE service actionis attempted,
3240                  * but there are insufficient device server resources to complete the
3241                  * operation, then the command shall be terminated with CHECK CONDITION
3242                  * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3243                  * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3244                  */
3245                 .key = ILLEGAL_REQUEST,
3246                 .asc = 0x55,
3247                 .ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3248         },
3249 };
3250
3251 /**
3252  * translate_sense_reason - translate a sense reason into T10 key, asc and ascq
3253  * @cmd: SCSI command in which the resulting sense buffer or SCSI status will
3254  *   be stored.
3255  * @reason: LIO sense reason code. If this argument has the value
3256  *   TCM_CHECK_CONDITION_UNIT_ATTENTION, try to dequeue a unit attention. If
3257  *   dequeuing a unit attention fails due to multiple commands being processed
3258  *   concurrently, set the command status to BUSY.
3259  *
3260  * Return: 0 upon success or -EINVAL if the sense buffer is too small.
3261  */
3262 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3263 {
3264         const struct sense_info *si;
3265         u8 *buffer = cmd->sense_buffer;
3266         int r = (__force int)reason;
3267         u8 key, asc, ascq;
3268         bool desc_format = target_sense_desc_format(cmd->se_dev);
3269
3270         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
3271                 si = &sense_info_table[r];
3272         else
3273                 si = &sense_info_table[(__force int)
3274                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3275
3276         key = si->key;
3277         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3278                 if (!core_scsi3_ua_for_check_condition(cmd, &key, &asc,
3279                                                        &ascq)) {
3280                         cmd->scsi_status = SAM_STAT_BUSY;
3281                         return;
3282                 }
3283         } else if (si->asc == 0) {
3284                 WARN_ON_ONCE(cmd->scsi_asc == 0);
3285                 asc = cmd->scsi_asc;
3286                 ascq = cmd->scsi_ascq;
3287         } else {
3288                 asc = si->asc;
3289                 ascq = si->ascq;
3290         }
3291
3292         cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3293         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3294         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3295         scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
3296         if (si->add_sector_info)
3297                 WARN_ON_ONCE(scsi_set_sense_information(buffer,
3298                                                         cmd->scsi_sense_length,
3299                                                         cmd->bad_sector) < 0);
3300 }
3301
3302 int
3303 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3304                 sense_reason_t reason, int from_transport)
3305 {
3306         unsigned long flags;
3307
3308         WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3309
3310         spin_lock_irqsave(&cmd->t_state_lock, flags);
3311         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3312                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3313                 return 0;
3314         }
3315         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3316         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3317
3318         if (!from_transport)
3319                 translate_sense_reason(cmd, reason);
3320
3321         trace_target_cmd_complete(cmd);
3322         return cmd->se_tfo->queue_status(cmd);
3323 }
3324 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3325
3326 /**
3327  * target_send_busy - Send SCSI BUSY status back to the initiator
3328  * @cmd: SCSI command for which to send a BUSY reply.
3329  *
3330  * Note: Only call this function if target_submit_cmd*() failed.
3331  */
3332 int target_send_busy(struct se_cmd *cmd)
3333 {
3334         WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3335
3336         cmd->scsi_status = SAM_STAT_BUSY;
3337         trace_target_cmd_complete(cmd);
3338         return cmd->se_tfo->queue_status(cmd);
3339 }
3340 EXPORT_SYMBOL(target_send_busy);
3341
3342 static void target_tmr_work(struct work_struct *work)
3343 {
3344         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3345         struct se_device *dev = cmd->se_dev;
3346         struct se_tmr_req *tmr = cmd->se_tmr_req;
3347         int ret;
3348
3349         if (cmd->transport_state & CMD_T_ABORTED)
3350                 goto aborted;
3351
3352         switch (tmr->function) {
3353         case TMR_ABORT_TASK:
3354                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3355                 break;
3356         case TMR_ABORT_TASK_SET:
3357         case TMR_CLEAR_ACA:
3358         case TMR_CLEAR_TASK_SET:
3359                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3360                 break;
3361         case TMR_LUN_RESET:
3362                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3363                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3364                                          TMR_FUNCTION_REJECTED;
3365                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3366                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3367                                                cmd->orig_fe_lun, 0x29,
3368                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3369                 }
3370                 break;
3371         case TMR_TARGET_WARM_RESET:
3372                 tmr->response = TMR_FUNCTION_REJECTED;
3373                 break;
3374         case TMR_TARGET_COLD_RESET:
3375                 tmr->response = TMR_FUNCTION_REJECTED;
3376                 break;
3377         default:
3378                 pr_err("Unknown TMR function: 0x%02x.\n",
3379                                 tmr->function);
3380                 tmr->response = TMR_FUNCTION_REJECTED;
3381                 break;
3382         }
3383
3384         if (cmd->transport_state & CMD_T_ABORTED)
3385                 goto aborted;
3386
3387         cmd->se_tfo->queue_tm_rsp(cmd);
3388
3389         transport_lun_remove_cmd(cmd);
3390         transport_cmd_check_stop_to_fabric(cmd);
3391         return;
3392
3393 aborted:
3394         target_handle_abort(cmd);
3395 }
3396
3397 int transport_generic_handle_tmr(
3398         struct se_cmd *cmd)
3399 {
3400         unsigned long flags;
3401         bool aborted = false;
3402
3403         spin_lock_irqsave(&cmd->t_state_lock, flags);
3404         if (cmd->transport_state & CMD_T_ABORTED) {
3405                 aborted = true;
3406         } else {
3407                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3408                 cmd->transport_state |= CMD_T_ACTIVE;
3409         }
3410         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3411
3412         if (aborted) {
3413                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d ref_tag: %llu tag: %llu\n",
3414                                     cmd->se_tmr_req->function,
3415                                     cmd->se_tmr_req->ref_task_tag, cmd->tag);
3416                 target_handle_abort(cmd);
3417                 return 0;
3418         }
3419
3420         INIT_WORK(&cmd->work, target_tmr_work);
3421         schedule_work(&cmd->work);
3422         return 0;
3423 }
3424 EXPORT_SYMBOL(transport_generic_handle_tmr);
3425
3426 bool
3427 target_check_wce(struct se_device *dev)
3428 {
3429         bool wce = false;
3430
3431         if (dev->transport->get_write_cache)
3432                 wce = dev->transport->get_write_cache(dev);
3433         else if (dev->dev_attrib.emulate_write_cache > 0)
3434                 wce = true;
3435
3436         return wce;
3437 }
3438
3439 bool
3440 target_check_fua(struct se_device *dev)
3441 {
3442         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3443 }