drivers/target/target_core_transport.c

   1 /*******************************************************************************
   2  * Filename:  target_core_transport.c
   3  *
   4  * This file contains the Generic Target Engine Core.
   5  *
   6  * (c) Copyright 2002-2012 RisingTide Systems LLC.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/net.h>
  27 #include <linux/delay.h>
  28 #include <linux/string.h>
  29 #include <linux/timer.h>
  30 #include <linux/slab.h>
  31 #include <linux/blkdev.h>
  32 #include <linux/spinlock.h>
  33 #include <linux/kthread.h>
  34 #include <linux/in.h>
  35 #include <linux/cdrom.h>
  36 #include <linux/module.h>
  37 #include <linux/ratelimit.h>
  38 #include <asm/unaligned.h>
  39 #include <net/sock.h>
  40 #include <net/tcp.h>
  41 #include <scsi/scsi.h>
  42 #include <scsi/scsi_cmnd.h>
  43 #include <scsi/scsi_tcq.h>
  44
  45 #include <target/target_core_base.h>
  46 #include <target/target_core_backend.h>
  47 #include <target/target_core_fabric.h>
  48 #include <target/target_core_configfs.h>
  49
  50 #include "target_core_internal.h"
  51 #include "target_core_alua.h"
  52 #include "target_core_pr.h"
  53 #include "target_core_ua.h"
  54
  55 static struct workqueue_struct *target_completion_wq;
  56 static struct kmem_cache *se_sess_cache;
  57 struct kmem_cache *se_ua_cache;
  58 struct kmem_cache *t10_pr_reg_cache;
  59 struct kmem_cache *t10_alua_lu_gp_cache;
  60 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  61 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  62 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
  63
  64 static void transport_complete_task_attr(struct se_cmd *cmd);
  65 static void transport_handle_queue_full(struct se_cmd *cmd,
  66                 struct se_device *dev);
  67 static int transport_generic_get_mem(struct se_cmd *cmd);
  68 static int target_get_sess_cmd(struct se_session *, struct se_cmd *, bool);
  69 static void transport_put_cmd(struct se_cmd *cmd);
  70 static void target_complete_ok_work(struct work_struct *work);
  71
  72 int init_se_kmem_caches(void)
  73 {
  74         se_sess_cache = kmem_cache_create("se_sess_cache",
  75                         sizeof(struct se_session), __alignof__(struct se_session),
  76                         0, NULL);
  77         if (!se_sess_cache) {
  78                 pr_err("kmem_cache_create() for struct se_session"
  79                                 " failed\n");
  80                 goto out;
  81         }
  82         se_ua_cache = kmem_cache_create("se_ua_cache",
  83                         sizeof(struct se_ua), __alignof__(struct se_ua),
  84                         0, NULL);
  85         if (!se_ua_cache) {
  86                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  87                 goto out_free_sess_cache;
  88         }
  89         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  90                         sizeof(struct t10_pr_registration),
  91                         __alignof__(struct t10_pr_registration), 0, NULL);
  92         if (!t10_pr_reg_cache) {
  93                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  94                                 " failed\n");
  95                 goto out_free_ua_cache;
  96         }
  97         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  98                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  99                         0, NULL);
 100         if (!t10_alua_lu_gp_cache) {
 101                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 102                                 " failed\n");
 103                 goto out_free_pr_reg_cache;
 104         }
 105         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 106                         sizeof(struct t10_alua_lu_gp_member),
 107                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 108         if (!t10_alua_lu_gp_mem_cache) {
 109                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 110                                 "cache failed\n");
 111                 goto out_free_lu_gp_cache;
 112         }
 113         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 114                         sizeof(struct t10_alua_tg_pt_gp),
 115                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 116         if (!t10_alua_tg_pt_gp_cache) {
 117                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 118                                 "cache failed\n");
 119                 goto out_free_lu_gp_mem_cache;
 120         }
 121         t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
 122                         "t10_alua_tg_pt_gp_mem_cache",
 123                         sizeof(struct t10_alua_tg_pt_gp_member),
 124                         __alignof__(struct t10_alua_tg_pt_gp_member),
 125                         0, NULL);
 126         if (!t10_alua_tg_pt_gp_mem_cache) {
 127                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 128                                 "mem_t failed\n");
 129                 goto out_free_tg_pt_gp_cache;
 130         }
 131
 132         target_completion_wq = alloc_workqueue("target_completion",
 133                                                WQ_MEM_RECLAIM, 0);
 134         if (!target_completion_wq)
 135                 goto out_free_tg_pt_gp_mem_cache;
 136
 137         return 0;
 138
 139 out_free_tg_pt_gp_mem_cache:
 140         kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 141 out_free_tg_pt_gp_cache:
 142         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 143 out_free_lu_gp_mem_cache:
 144         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 145 out_free_lu_gp_cache:
 146         kmem_cache_destroy(t10_alua_lu_gp_cache);
 147 out_free_pr_reg_cache:
 148         kmem_cache_destroy(t10_pr_reg_cache);
 149 out_free_ua_cache:
 150         kmem_cache_destroy(se_ua_cache);
 151 out_free_sess_cache:
 152         kmem_cache_destroy(se_sess_cache);
 153 out:
 154         return -ENOMEM;
 155 }
 156
 157 void release_se_kmem_caches(void)
 158 {
 159         destroy_workqueue(target_completion_wq);
 160         kmem_cache_destroy(se_sess_cache);
 161         kmem_cache_destroy(se_ua_cache);
 162         kmem_cache_destroy(t10_pr_reg_cache);
 163         kmem_cache_destroy(t10_alua_lu_gp_cache);
 164         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 165         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 166         kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 167 }
 168
 169 /* This code ensures unique mib indexes are handed out. */
 170 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 171 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 172
 173 /*
 174  * Allocate a new row index for the entry type specified
 175  */
 176 u32 scsi_get_new_index(scsi_index_t type)
 177 {
 178         u32 new_index;
 179
 180         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 181
 182         spin_lock(&scsi_mib_index_lock);
 183         new_index = ++scsi_mib_index[type];
 184         spin_unlock(&scsi_mib_index_lock);
 185
 186         return new_index;
 187 }
 188
 189 void transport_subsystem_check_init(void)
 190 {
 191         int ret;
 192         static int sub_api_initialized;
 193
 194         if (sub_api_initialized)
 195                 return;
 196
 197         ret = request_module("target_core_iblock");
 198         if (ret != 0)
 199                 pr_err("Unable to load target_core_iblock\n");
 200
 201         ret = request_module("target_core_file");
 202         if (ret != 0)
 203                 pr_err("Unable to load target_core_file\n");
 204
 205         ret = request_module("target_core_pscsi");
 206         if (ret != 0)
 207                 pr_err("Unable to load target_core_pscsi\n");
 208
 209         sub_api_initialized = 1;
 210 }
 211
 212 struct se_session *transport_init_session(void)
 213 {
 214         struct se_session *se_sess;
 215
 216         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 217         if (!se_sess) {
 218                 pr_err("Unable to allocate struct se_session from"
 219                                 " se_sess_cache\n");
 220                 return ERR_PTR(-ENOMEM);
 221         }
 222         INIT_LIST_HEAD(&se_sess->sess_list);
 223         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 224         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 225         spin_lock_init(&se_sess->sess_cmd_lock);
 226         kref_init(&se_sess->sess_kref);
 227
 228         return se_sess;
 229 }
 230 EXPORT_SYMBOL(transport_init_session);
 231
 232 /*
 233  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 234  */
 235 void __transport_register_session(
 236         struct se_portal_group *se_tpg,
 237         struct se_node_acl *se_nacl,
 238         struct se_session *se_sess,
 239         void *fabric_sess_ptr)
 240 {
 241         unsigned char buf[PR_REG_ISID_LEN];
 242
 243         se_sess->se_tpg = se_tpg;
 244         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 245         /*
 246          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 247          *
 248          * Only set for struct se_session's that will actually be moving I/O.
 249          * eg: *NOT* discovery sessions.
 250          */
 251         if (se_nacl) {
 252                 /*
 253                  * If the fabric module supports an ISID based TransportID,
 254                  * save this value in binary from the fabric I_T Nexus now.
 255                  */
 256                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 257                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 258                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 259                                         &buf[0], PR_REG_ISID_LEN);
 260                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 261                 }
 262                 kref_get(&se_nacl->acl_kref);
 263
 264                 spin_lock_irq(&se_nacl->nacl_sess_lock);
 265                 /*
 266                  * The se_nacl->nacl_sess pointer will be set to the
 267                  * last active I_T Nexus for each struct se_node_acl.
 268                  */
 269                 se_nacl->nacl_sess = se_sess;
 270
 271                 list_add_tail(&se_sess->sess_acl_list,
 272                               &se_nacl->acl_sess_list);
 273                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
 274         }
 275         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 276
 277         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 278                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 279 }
 280 EXPORT_SYMBOL(__transport_register_session);
 281
 282 void transport_register_session(
 283         struct se_portal_group *se_tpg,
 284         struct se_node_acl *se_nacl,
 285         struct se_session *se_sess,
 286         void *fabric_sess_ptr)
 287 {
 288         unsigned long flags;
 289
 290         spin_lock_irqsave(&se_tpg->session_lock, flags);
 291         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 292         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 293 }
 294 EXPORT_SYMBOL(transport_register_session);
 295
 296 static void target_release_session(struct kref *kref)
 297 {
 298         struct se_session *se_sess = container_of(kref,
 299                         struct se_session, sess_kref);
 300         struct se_portal_group *se_tpg = se_sess->se_tpg;
 301
 302         se_tpg->se_tpg_tfo->close_session(se_sess);
 303 }
 304
 305 void target_get_session(struct se_session *se_sess)
 306 {
 307         kref_get(&se_sess->sess_kref);
 308 }
 309 EXPORT_SYMBOL(target_get_session);
 310
 311 void target_put_session(struct se_session *se_sess)
 312 {
 313         struct se_portal_group *tpg = se_sess->se_tpg;
 314
 315         if (tpg->se_tpg_tfo->put_session != NULL) {
 316                 tpg->se_tpg_tfo->put_session(se_sess);
 317                 return;
 318         }
 319         kref_put(&se_sess->sess_kref, target_release_session);
 320 }
 321 EXPORT_SYMBOL(target_put_session);
 322
 323 static void target_complete_nacl(struct kref *kref)
 324 {
 325         struct se_node_acl *nacl = container_of(kref,
 326                                 struct se_node_acl, acl_kref);
 327
 328         complete(&nacl->acl_free_comp);
 329 }
 330
 331 void target_put_nacl(struct se_node_acl *nacl)
 332 {
 333         kref_put(&nacl->acl_kref, target_complete_nacl);
 334 }
 335
 336 void transport_deregister_session_configfs(struct se_session *se_sess)
 337 {
 338         struct se_node_acl *se_nacl;
 339         unsigned long flags;
 340         /*
 341          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 342          */
 343         se_nacl = se_sess->se_node_acl;
 344         if (se_nacl) {
 345                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 346                 if (se_nacl->acl_stop == 0)
 347                         list_del(&se_sess->sess_acl_list);
 348                 /*
 349                  * If the session list is empty, then clear the pointer.
 350                  * Otherwise, set the struct se_session pointer from the tail
 351                  * element of the per struct se_node_acl active session list.
 352                  */
 353                 if (list_empty(&se_nacl->acl_sess_list))
 354                         se_nacl->nacl_sess = NULL;
 355                 else {
 356                         se_nacl->nacl_sess = container_of(
 357                                         se_nacl->acl_sess_list.prev,
 358                                         struct se_session, sess_acl_list);
 359                 }
 360                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 361         }
 362 }
 363 EXPORT_SYMBOL(transport_deregister_session_configfs);
 364
 365 void transport_free_session(struct se_session *se_sess)
 366 {
 367         kmem_cache_free(se_sess_cache, se_sess);
 368 }
 369 EXPORT_SYMBOL(transport_free_session);
 370
 371 void transport_deregister_session(struct se_session *se_sess)
 372 {
 373         struct se_portal_group *se_tpg = se_sess->se_tpg;
 374         struct target_core_fabric_ops *se_tfo;
 375         struct se_node_acl *se_nacl;
 376         unsigned long flags;
 377         bool comp_nacl = true;
 378
 379         if (!se_tpg) {
 380                 transport_free_session(se_sess);
 381                 return;
 382         }
 383         se_tfo = se_tpg->se_tpg_tfo;
 384
 385         spin_lock_irqsave(&se_tpg->session_lock, flags);
 386         list_del(&se_sess->sess_list);
 387         se_sess->se_tpg = NULL;
 388         se_sess->fabric_sess_ptr = NULL;
 389         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 390
 391         /*
 392          * Determine if we need to do extra work for this initiator node's
 393          * struct se_node_acl if it had been previously dynamically generated.
 394          */
 395         se_nacl = se_sess->se_node_acl;
 396
 397         spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
 398         if (se_nacl && se_nacl->dynamic_node_acl) {
 399                 if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 400                         list_del(&se_nacl->acl_list);
 401                         se_tpg->num_node_acls--;
 402                         spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
 403                         core_tpg_wait_for_nacl_pr_ref(se_nacl);
 404                         core_free_device_list_for_node(se_nacl, se_tpg);
 405                         se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
 406
 407                         comp_nacl = false;
 408                         spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
 409                 }
 410         }
 411         spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
 412
 413         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 414                 se_tpg->se_tpg_tfo->get_fabric_name());
 415         /*
 416          * If last kref is dropping now for an explict NodeACL, awake sleeping
 417          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 418          * removal context.
 419          */
 420         if (se_nacl && comp_nacl == true)
 421                 target_put_nacl(se_nacl);
 422
 423         transport_free_session(se_sess);
 424 }
 425 EXPORT_SYMBOL(transport_deregister_session);
 426
 427 /*
 428  * Called with cmd->t_state_lock held.
 429  */
 430 static void target_remove_from_state_list(struct se_cmd *cmd)
 431 {
 432         struct se_device *dev = cmd->se_dev;
 433         unsigned long flags;
 434
 435         if (!dev)
 436                 return;
 437
 438         if (cmd->transport_state & CMD_T_BUSY)
 439                 return;
 440
 441         spin_lock_irqsave(&dev->execute_task_lock, flags);
 442         if (cmd->state_active) {
 443                 list_del(&cmd->state_list);
 444                 cmd->state_active = false;
 445         }
 446         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 447 }
 448
 449 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists)
 450 {
 451         unsigned long flags;
 452
 453         spin_lock_irqsave(&cmd->t_state_lock, flags);
 454         /*
 455          * Determine if IOCTL context caller in requesting the stopping of this
 456          * command for LUN shutdown purposes.
 457          */
 458         if (cmd->transport_state & CMD_T_LUN_STOP) {
 459                 pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
 460                         __func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
 461
 462                 cmd->transport_state &= ~CMD_T_ACTIVE;
 463                 if (remove_from_lists)
 464                         target_remove_from_state_list(cmd);
 465                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 466
 467                 complete(&cmd->transport_lun_stop_comp);
 468                 return 1;
 469         }
 470
 471         if (remove_from_lists) {
 472                 target_remove_from_state_list(cmd);
 473
 474                 /*
 475                  * Clear struct se_cmd->se_lun before the handoff to FE.
 476                  */
 477                 cmd->se_lun = NULL;
 478         }
 479
 480         /*
 481          * Determine if frontend context caller is requesting the stopping of
 482          * this command for frontend exceptions.
 483          */
 484         if (cmd->transport_state & CMD_T_STOP) {
 485                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
 486                         __func__, __LINE__,
 487                         cmd->se_tfo->get_task_tag(cmd));
 488
 489                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 490
 491                 complete(&cmd->t_transport_stop_comp);
 492                 return 1;
 493         }
 494
 495         cmd->transport_state &= ~CMD_T_ACTIVE;
 496         if (remove_from_lists) {
 497                 /*
 498                  * Some fabric modules like tcm_loop can release
 499                  * their internally allocated I/O reference now and
 500                  * struct se_cmd now.
 501                  *
 502                  * Fabric modules are expected to return '1' here if the
 503                  * se_cmd being passed is released at this point,
 504                  * or zero if not being released.
 505                  */
 506                 if (cmd->se_tfo->check_stop_free != NULL) {
 507                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 508                         return cmd->se_tfo->check_stop_free(cmd);
 509                 }
 510         }
 511
 512         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 513         return 0;
 514 }
 515
 516 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 517 {
 518         return transport_cmd_check_stop(cmd, true);
 519 }
 520
 521 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 522 {
 523         struct se_lun *lun = cmd->se_lun;
 524         unsigned long flags;
 525
 526         if (!lun)
 527                 return;
 528
 529         spin_lock_irqsave(&cmd->t_state_lock, flags);
 530         if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
 531                 cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
 532                 target_remove_from_state_list(cmd);
 533         }
 534         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 535
 536         spin_lock_irqsave(&lun->lun_cmd_lock, flags);
 537         if (!list_empty(&cmd->se_lun_node))
 538                 list_del_init(&cmd->se_lun_node);
 539         spin_unlock_irqrestore(&lun->lun_cmd_lock, flags);
 540 }
 541
 542 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 543 {
 544         if (transport_cmd_check_stop_to_fabric(cmd))
 545                 return;
 546         if (remove)
 547                 transport_put_cmd(cmd);
 548 }
 549
 550 static void target_complete_failure_work(struct work_struct *work)
 551 {
 552         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 553
 554         transport_generic_request_failure(cmd,
 555                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 556 }
 557
 558 /*
 559  * Used when asking transport to copy Sense Data from the underlying
 560  * Linux/SCSI struct scsi_cmnd
 561  */
 562 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 563 {
 564         struct se_device *dev = cmd->se_dev;
 565
 566         WARN_ON(!cmd->se_lun);
 567
 568         if (!dev)
 569                 return NULL;
 570
 571         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 572                 return NULL;
 573
 574         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 575
 576         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 577                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 578         return cmd->sense_buffer;
 579 }
 580
 581 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 582 {
 583         struct se_device *dev = cmd->se_dev;
 584         int success = scsi_status == GOOD;
 585         unsigned long flags;
 586
 587         cmd->scsi_status = scsi_status;
 588
 589
 590         spin_lock_irqsave(&cmd->t_state_lock, flags);
 591         cmd->transport_state &= ~CMD_T_BUSY;
 592
 593         if (dev && dev->transport->transport_complete) {
 594                 dev->transport->transport_complete(cmd,
 595                                 cmd->t_data_sg,
 596                                 transport_get_sense_buffer(cmd));
 597                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 598                         success = 1;
 599         }
 600
 601         /*
 602          * See if we are waiting to complete for an exception condition.
 603          */
 604         if (cmd->transport_state & CMD_T_REQUEST_STOP) {
 605                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 606                 complete(&cmd->task_stop_comp);
 607                 return;
 608         }
 609
 610         if (!success)
 611                 cmd->transport_state |= CMD_T_FAILED;
 612
 613         /*
 614          * Check for case where an explict ABORT_TASK has been received
 615          * and transport_wait_for_tasks() will be waiting for completion..
 616          */
 617         if (cmd->transport_state & CMD_T_ABORTED &&
 618             cmd->transport_state & CMD_T_STOP) {
 619                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 620                 complete(&cmd->t_transport_stop_comp);
 621                 return;
 622         } else if (cmd->transport_state & CMD_T_FAILED) {
 623                 INIT_WORK(&cmd->work, target_complete_failure_work);
 624         } else {
 625                 INIT_WORK(&cmd->work, target_complete_ok_work);
 626         }
 627
 628         cmd->t_state = TRANSPORT_COMPLETE;
 629         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 630         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 631
 632         queue_work(target_completion_wq, &cmd->work);
 633 }
 634 EXPORT_SYMBOL(target_complete_cmd);
 635
 636 static void target_add_to_state_list(struct se_cmd *cmd)
 637 {
 638         struct se_device *dev = cmd->se_dev;
 639         unsigned long flags;
 640
 641         spin_lock_irqsave(&dev->execute_task_lock, flags);
 642         if (!cmd->state_active) {
 643                 list_add_tail(&cmd->state_list, &dev->state_list);
 644                 cmd->state_active = true;
 645         }
 646         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 647 }
 648
 649 /*
 650  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 651  */
 652 static void transport_write_pending_qf(struct se_cmd *cmd);
 653 static void transport_complete_qf(struct se_cmd *cmd);
 654
 655 void target_qf_do_work(struct work_struct *work)
 656 {
 657         struct se_device *dev = container_of(work, struct se_device,
 658                                         qf_work_queue);
 659         LIST_HEAD(qf_cmd_list);
 660         struct se_cmd *cmd, *cmd_tmp;
 661
 662         spin_lock_irq(&dev->qf_cmd_lock);
 663         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 664         spin_unlock_irq(&dev->qf_cmd_lock);
 665
 666         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 667                 list_del(&cmd->se_qf_node);
 668                 atomic_dec(&dev->dev_qf_count);
 669                 smp_mb__after_atomic_dec();
 670
 671                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 672                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 673                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 674                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 675                         : "UNKNOWN");
 676
 677                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 678                         transport_write_pending_qf(cmd);
 679                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 680                         transport_complete_qf(cmd);
 681         }
 682 }
 683
 684 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 685 {
 686         switch (cmd->data_direction) {
 687         case DMA_NONE:
 688                 return "NONE";
 689         case DMA_FROM_DEVICE:
 690                 return "READ";
 691         case DMA_TO_DEVICE:
 692                 return "WRITE";
 693         case DMA_BIDIRECTIONAL:
 694                 return "BIDI";
 695         default:
 696                 break;
 697         }
 698
 699         return "UNKNOWN";
 700 }
 701
 702 void transport_dump_dev_state(
 703         struct se_device *dev,
 704         char *b,
 705         int *bl)
 706 {
 707         *bl += sprintf(b + *bl, "Status: ");
 708         if (dev->export_count)
 709                 *bl += sprintf(b + *bl, "ACTIVATED");
 710         else
 711                 *bl += sprintf(b + *bl, "DEACTIVATED");
 712
 713         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 714         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 715                 dev->dev_attrib.block_size,
 716                 dev->dev_attrib.hw_max_sectors);
 717         *bl += sprintf(b + *bl, "        ");
 718 }
 719
 720 void transport_dump_vpd_proto_id(
 721         struct t10_vpd *vpd,
 722         unsigned char *p_buf,
 723         int p_buf_len)
 724 {
 725         unsigned char buf[VPD_TMP_BUF_SIZE];
 726         int len;
 727
 728         memset(buf, 0, VPD_TMP_BUF_SIZE);
 729         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 730
 731         switch (vpd->protocol_identifier) {
 732         case 0x00:
 733                 sprintf(buf+len, "Fibre Channel\n");
 734                 break;
 735         case 0x10:
 736                 sprintf(buf+len, "Parallel SCSI\n");
 737                 break;
 738         case 0x20:
 739                 sprintf(buf+len, "SSA\n");
 740                 break;
 741         case 0x30:
 742                 sprintf(buf+len, "IEEE 1394\n");
 743                 break;
 744         case 0x40:
 745                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 746                                 " Protocol\n");
 747                 break;
 748         case 0x50:
 749                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 750                 break;
 751         case 0x60:
 752                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 753                 break;
 754         case 0x70:
 755                 sprintf(buf+len, "Automation/Drive Interface Transport"
 756                                 " Protocol\n");
 757                 break;
 758         case 0x80:
 759                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 760                 break;
 761         default:
 762                 sprintf(buf+len, "Unknown 0x%02x\n",
 763                                 vpd->protocol_identifier);
 764                 break;
 765         }
 766
 767         if (p_buf)
 768                 strncpy(p_buf, buf, p_buf_len);
 769         else
 770                 pr_debug("%s", buf);
 771 }
 772
 773 void
 774 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 775 {
 776         /*
 777          * Check if the Protocol Identifier Valid (PIV) bit is set..
 778          *
 779          * from spc3r23.pdf section 7.5.1
 780          */
 781          if (page_83[1] & 0x80) {
 782                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 783                 vpd->protocol_identifier_set = 1;
 784                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 785         }
 786 }
 787 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 788
 789 int transport_dump_vpd_assoc(
 790         struct t10_vpd *vpd,
 791         unsigned char *p_buf,
 792         int p_buf_len)
 793 {
 794         unsigned char buf[VPD_TMP_BUF_SIZE];
 795         int ret = 0;
 796         int len;
 797
 798         memset(buf, 0, VPD_TMP_BUF_SIZE);
 799         len = sprintf(buf, "T10 VPD Identifier Association: ");
 800
 801         switch (vpd->association) {
 802         case 0x00:
 803                 sprintf(buf+len, "addressed logical unit\n");
 804                 break;
 805         case 0x10:
 806                 sprintf(buf+len, "target port\n");
 807                 break;
 808         case 0x20:
 809                 sprintf(buf+len, "SCSI target device\n");
 810                 break;
 811         default:
 812                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 813                 ret = -EINVAL;
 814                 break;
 815         }
 816
 817         if (p_buf)
 818                 strncpy(p_buf, buf, p_buf_len);
 819         else
 820                 pr_debug("%s", buf);
 821
 822         return ret;
 823 }
 824
 825 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 826 {
 827         /*
 828          * The VPD identification association..
 829          *
 830          * from spc3r23.pdf Section 7.6.3.1 Table 297
 831          */
 832         vpd->association = (page_83[1] & 0x30);
 833         return transport_dump_vpd_assoc(vpd, NULL, 0);
 834 }
 835 EXPORT_SYMBOL(transport_set_vpd_assoc);
 836
 837 int transport_dump_vpd_ident_type(
 838         struct t10_vpd *vpd,
 839         unsigned char *p_buf,
 840         int p_buf_len)
 841 {
 842         unsigned char buf[VPD_TMP_BUF_SIZE];
 843         int ret = 0;
 844         int len;
 845
 846         memset(buf, 0, VPD_TMP_BUF_SIZE);
 847         len = sprintf(buf, "T10 VPD Identifier Type: ");
 848
 849         switch (vpd->device_identifier_type) {
 850         case 0x00:
 851                 sprintf(buf+len, "Vendor specific\n");
 852                 break;
 853         case 0x01:
 854                 sprintf(buf+len, "T10 Vendor ID based\n");
 855                 break;
 856         case 0x02:
 857                 sprintf(buf+len, "EUI-64 based\n");
 858                 break;
 859         case 0x03:
 860                 sprintf(buf+len, "NAA\n");
 861                 break;
 862         case 0x04:
 863                 sprintf(buf+len, "Relative target port identifier\n");
 864                 break;
 865         case 0x08:
 866                 sprintf(buf+len, "SCSI name string\n");
 867                 break;
 868         default:
 869                 sprintf(buf+len, "Unsupported: 0x%02x\n",
 870                                 vpd->device_identifier_type);
 871                 ret = -EINVAL;
 872                 break;
 873         }
 874
 875         if (p_buf) {
 876                 if (p_buf_len < strlen(buf)+1)
 877                         return -EINVAL;
 878                 strncpy(p_buf, buf, p_buf_len);
 879         } else {
 880                 pr_debug("%s", buf);
 881         }
 882
 883         return ret;
 884 }
 885
 886 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
 887 {
 888         /*
 889          * The VPD identifier type..
 890          *
 891          * from spc3r23.pdf Section 7.6.3.1 Table 298
 892          */
 893         vpd->device_identifier_type = (page_83[1] & 0x0f);
 894         return transport_dump_vpd_ident_type(vpd, NULL, 0);
 895 }
 896 EXPORT_SYMBOL(transport_set_vpd_ident_type);
 897
 898 int transport_dump_vpd_ident(
 899         struct t10_vpd *vpd,
 900         unsigned char *p_buf,
 901         int p_buf_len)
 902 {
 903         unsigned char buf[VPD_TMP_BUF_SIZE];
 904         int ret = 0;
 905
 906         memset(buf, 0, VPD_TMP_BUF_SIZE);
 907
 908         switch (vpd->device_identifier_code_set) {
 909         case 0x01: /* Binary */
 910                 sprintf(buf, "T10 VPD Binary Device Identifier: %s\n",
 911                         &vpd->device_identifier[0]);
 912                 break;
 913         case 0x02: /* ASCII */
 914                 sprintf(buf, "T10 VPD ASCII Device Identifier: %s\n",
 915                         &vpd->device_identifier[0]);
 916                 break;
 917         case 0x03: /* UTF-8 */
 918                 sprintf(buf, "T10 VPD UTF-8 Device Identifier: %s\n",
 919                         &vpd->device_identifier[0]);
 920                 break;
 921         default:
 922                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
 923                         " 0x%02x", vpd->device_identifier_code_set);
 924                 ret = -EINVAL;
 925                 break;
 926         }
 927
 928         if (p_buf)
 929                 strncpy(p_buf, buf, p_buf_len);
 930         else
 931                 pr_debug("%s", buf);
 932
 933         return ret;
 934 }
 935
 936 int
 937 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
 938 {
 939         static const char hex_str[] = "0123456789abcdef";
 940         int j = 0, i = 4; /* offset to start of the identifier */
 941
 942         /*
 943          * The VPD Code Set (encoding)
 944          *
 945          * from spc3r23.pdf Section 7.6.3.1 Table 296
 946          */
 947         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
 948         switch (vpd->device_identifier_code_set) {
 949         case 0x01: /* Binary */
 950                 vpd->device_identifier[j++] =
 951                                 hex_str[vpd->device_identifier_type];
 952                 while (i < (4 + page_83[3])) {
 953                         vpd->device_identifier[j++] =
 954                                 hex_str[(page_83[i] & 0xf0) >> 4];
 955                         vpd->device_identifier[j++] =
 956                                 hex_str[page_83[i] & 0x0f];
 957                         i++;
 958                 }
 959                 break;
 960         case 0x02: /* ASCII */
 961         case 0x03: /* UTF-8 */
 962                 while (i < (4 + page_83[3]))
 963                         vpd->device_identifier[j++] = page_83[i++];
 964                 break;
 965         default:
 966                 break;
 967         }
 968
 969         return transport_dump_vpd_ident(vpd, NULL, 0);
 970 }
 971 EXPORT_SYMBOL(transport_set_vpd_ident);
 972
 973 sense_reason_t
 974 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
 975 {
 976         struct se_device *dev = cmd->se_dev;
 977
 978         if (cmd->unknown_data_length) {
 979                 cmd->data_length = size;
 980         } else if (size != cmd->data_length) {
 981                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
 982                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
 983                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
 984                                 cmd->data_length, size, cmd->t_task_cdb[0]);
 985
 986                 if (cmd->data_direction == DMA_TO_DEVICE) {
 987                         pr_err("Rejecting underflow/overflow"
 988                                         " WRITE data\n");
 989                         return TCM_INVALID_CDB_FIELD;
 990                 }
 991                 /*
 992                  * Reject READ_* or WRITE_* with overflow/underflow for
 993                  * type SCF_SCSI_DATA_CDB.
 994                  */
 995                 if (dev->dev_attrib.block_size != 512)  {
 996                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
 997                                 " CDB on non 512-byte sector setup subsystem"
 998                                 " plugin: %s\n", dev->transport->name);
 999                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1000                         return TCM_INVALID_CDB_FIELD;
1001                 }
1002                 /*
1003                  * For the overflow case keep the existing fabric provided
1004                  * ->data_length.  Otherwise for the underflow case, reset
1005                  * ->data_length to the smaller SCSI expected data transfer
1006                  * length.
1007                  */
1008                 if (size > cmd->data_length) {
1009                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1010                         cmd->residual_count = (size - cmd->data_length);
1011                 } else {
1012                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1013                         cmd->residual_count = (cmd->data_length - size);
1014                         cmd->data_length = size;
1015                 }
1016         }
1017
1018         return 0;
1019
1020 }
1021
1022 /*
1023  * Used by fabric modules containing a local struct se_cmd within their
1024  * fabric dependent per I/O descriptor.
1025  */
1026 void transport_init_se_cmd(
1027         struct se_cmd *cmd,
1028         struct target_core_fabric_ops *tfo,
1029         struct se_session *se_sess,
1030         u32 data_length,
1031         int data_direction,
1032         int task_attr,
1033         unsigned char *sense_buffer)
1034 {
1035         INIT_LIST_HEAD(&cmd->se_lun_node);
1036         INIT_LIST_HEAD(&cmd->se_delayed_node);
1037         INIT_LIST_HEAD(&cmd->se_qf_node);
1038         INIT_LIST_HEAD(&cmd->se_cmd_list);
1039         INIT_LIST_HEAD(&cmd->state_list);
1040         init_completion(&cmd->transport_lun_fe_stop_comp);
1041         init_completion(&cmd->transport_lun_stop_comp);
1042         init_completion(&cmd->t_transport_stop_comp);
1043         init_completion(&cmd->cmd_wait_comp);
1044         init_completion(&cmd->task_stop_comp);
1045         spin_lock_init(&cmd->t_state_lock);
1046         cmd->transport_state = CMD_T_DEV_ACTIVE;
1047
1048         cmd->se_tfo = tfo;
1049         cmd->se_sess = se_sess;
1050         cmd->data_length = data_length;
1051         cmd->data_direction = data_direction;
1052         cmd->sam_task_attr = task_attr;
1053         cmd->sense_buffer = sense_buffer;
1054
1055         cmd->state_active = false;
1056 }
1057 EXPORT_SYMBOL(transport_init_se_cmd);
1058
1059 static sense_reason_t
1060 transport_check_alloc_task_attr(struct se_cmd *cmd)
1061 {
1062         struct se_device *dev = cmd->se_dev;
1063
1064         /*
1065          * Check if SAM Task Attribute emulation is enabled for this
1066          * struct se_device storage object
1067          */
1068         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1069                 return 0;
1070
1071         if (cmd->sam_task_attr == MSG_ACA_TAG) {
1072                 pr_debug("SAM Task Attribute ACA"
1073                         " emulation is not supported\n");
1074                 return TCM_INVALID_CDB_FIELD;
1075         }
1076         /*
1077          * Used to determine when ORDERED commands should go from
1078          * Dormant to Active status.
1079          */
1080         cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1081         smp_mb__after_atomic_inc();
1082         pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1083                         cmd->se_ordered_id, cmd->sam_task_attr,
1084                         dev->transport->name);
1085         return 0;
1086 }
1087
1088 sense_reason_t
1089 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1090 {
1091         struct se_device *dev = cmd->se_dev;
1092         unsigned long flags;
1093         sense_reason_t ret;
1094
1095         /*
1096          * Ensure that the received CDB is less than the max (252 + 8) bytes
1097          * for VARIABLE_LENGTH_CMD
1098          */
1099         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1100                 pr_err("Received SCSI CDB with command_size: %d that"
1101                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1102                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1103                 return TCM_INVALID_CDB_FIELD;
1104         }
1105         /*
1106          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1107          * allocate the additional extended CDB buffer now..  Otherwise
1108          * setup the pointer from __t_task_cdb to t_task_cdb.
1109          */
1110         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1111                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1112                                                 GFP_KERNEL);
1113                 if (!cmd->t_task_cdb) {
1114                         pr_err("Unable to allocate cmd->t_task_cdb"
1115                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1116                                 scsi_command_size(cdb),
1117                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1118                         return TCM_OUT_OF_RESOURCES;
1119                 }
1120         } else
1121                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1122         /*
1123          * Copy the original CDB into cmd->
1124          */
1125         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1126
1127         /*
1128          * Check for an existing UNIT ATTENTION condition
1129          */
1130         ret = target_scsi3_ua_check(cmd);
1131         if (ret)
1132                 return ret;
1133
1134         ret = target_alua_state_check(cmd);
1135         if (ret)
1136                 return ret;
1137
1138         ret = target_check_reservation(cmd);
1139         if (ret)
1140                 return ret;
1141
1142         ret = dev->transport->parse_cdb(cmd);
1143         if (ret)
1144                 return ret;
1145
1146         ret = transport_check_alloc_task_attr(cmd);
1147         if (ret)
1148                 return ret;
1149
1150         spin_lock_irqsave(&cmd->t_state_lock, flags);
1151         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1152         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1153
1154         spin_lock(&cmd->se_lun->lun_sep_lock);
1155         if (cmd->se_lun->lun_sep)
1156                 cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1157         spin_unlock(&cmd->se_lun->lun_sep_lock);
1158         return 0;
1159 }
1160 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1161
1162 /*
1163  * Used by fabric module frontends to queue tasks directly.
1164  * Many only be used from process context only
1165  */
1166 int transport_handle_cdb_direct(
1167         struct se_cmd *cmd)
1168 {
1169         sense_reason_t ret;
1170
1171         if (!cmd->se_lun) {
1172                 dump_stack();
1173                 pr_err("cmd->se_lun is NULL\n");
1174                 return -EINVAL;
1175         }
1176         if (in_interrupt()) {
1177                 dump_stack();
1178                 pr_err("transport_generic_handle_cdb cannot be called"
1179                                 " from interrupt context\n");
1180                 return -EINVAL;
1181         }
1182         /*
1183          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1184          * outstanding descriptors are handled correctly during shutdown via
1185          * transport_wait_for_tasks()
1186          *
1187          * Also, we don't take cmd->t_state_lock here as we only expect
1188          * this to be called for initial descriptor submission.
1189          */
1190         cmd->t_state = TRANSPORT_NEW_CMD;
1191         cmd->transport_state |= CMD_T_ACTIVE;
1192
1193         /*
1194          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1195          * so follow TRANSPORT_NEW_CMD processing thread context usage
1196          * and call transport_generic_request_failure() if necessary..
1197          */
1198         ret = transport_generic_new_cmd(cmd);
1199         if (ret)
1200                 transport_generic_request_failure(cmd, ret);
1201         return 0;
1202 }
1203 EXPORT_SYMBOL(transport_handle_cdb_direct);
1204
1205 static sense_reason_t
1206 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1207                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1208 {
1209         if (!sgl || !sgl_count)
1210                 return 0;
1211
1212         /*
1213          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1214          * scatterlists already have been set to follow what the fabric
1215          * passes for the original expected data transfer length.
1216          */
1217         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1218                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1219                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1220                 return TCM_INVALID_CDB_FIELD;
1221         }
1222
1223         cmd->t_data_sg = sgl;
1224         cmd->t_data_nents = sgl_count;
1225
1226         if (sgl_bidi && sgl_bidi_count) {
1227                 cmd->t_bidi_data_sg = sgl_bidi;
1228                 cmd->t_bidi_data_nents = sgl_bidi_count;
1229         }
1230         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1231         return 0;
1232 }
1233
1234 /*
1235  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1236  *                       se_cmd + use pre-allocated SGL memory.
1237  *
1238  * @se_cmd: command descriptor to submit
1239  * @se_sess: associated se_sess for endpoint
1240  * @cdb: pointer to SCSI CDB
1241  * @sense: pointer to SCSI sense buffer
1242  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1243  * @data_length: fabric expected data transfer length
1244  * @task_addr: SAM task attribute
1245  * @data_dir: DMA data direction
1246  * @flags: flags for command submission from target_sc_flags_tables
1247  * @sgl: struct scatterlist memory for unidirectional mapping
1248  * @sgl_count: scatterlist count for unidirectional mapping
1249  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1250  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1251  *
1252  * Returns non zero to signal active I/O shutdown failure.  All other
1253  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1254  * but still return zero here.
1255  *
1256  * This may only be called from process context, and also currently
1257  * assumes internal allocation of fabric payload buffer by target-core.
1258  */
1259 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1260                 unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1261                 u32 data_length, int task_attr, int data_dir, int flags,
1262                 struct scatterlist *sgl, u32 sgl_count,
1263                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1264 {
1265         struct se_portal_group *se_tpg;
1266         sense_reason_t rc;
1267         int ret;
1268
1269         se_tpg = se_sess->se_tpg;
1270         BUG_ON(!se_tpg);
1271         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1272         BUG_ON(in_interrupt());
1273         /*
1274          * Initialize se_cmd for target operation.  From this point
1275          * exceptions are handled by sending exception status via
1276          * target_core_fabric_ops->queue_status() callback
1277          */
1278         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1279                                 data_length, data_dir, task_attr, sense);
1280         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1281                 se_cmd->unknown_data_length = 1;
1282         /*
1283          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1284          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1285          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1286          * kref_put() to happen during fabric packet acknowledgement.
1287          */
1288         ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1289         if (ret)
1290                 return ret;
1291         /*
1292          * Signal bidirectional data payloads to target-core
1293          */
1294         if (flags & TARGET_SCF_BIDI_OP)
1295                 se_cmd->se_cmd_flags |= SCF_BIDI;
1296         /*
1297          * Locate se_lun pointer and attach it to struct se_cmd
1298          */
1299         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1300         if (rc) {
1301                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1302                 target_put_sess_cmd(se_sess, se_cmd);
1303                 return 0;
1304         }
1305
1306         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1307         if (rc != 0) {
1308                 transport_generic_request_failure(se_cmd, rc);
1309                 return 0;
1310         }
1311         /*
1312          * When a non zero sgl_count has been passed perform SGL passthrough
1313          * mapping for pre-allocated fabric memory instead of having target
1314          * core perform an internal SGL allocation..
1315          */
1316         if (sgl_count != 0) {
1317                 BUG_ON(!sgl);
1318
1319                 /*
1320                  * A work-around for tcm_loop as some userspace code via
1321                  * scsi-generic do not memset their associated read buffers,
1322                  * so go ahead and do that here for type non-data CDBs.  Also
1323                  * note that this is currently guaranteed to be a single SGL
1324                  * for this case by target core in target_setup_cmd_from_cdb()
1325                  * -> transport_generic_cmd_sequencer().
1326                  */
1327                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1328                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1329                         unsigned char *buf = NULL;
1330
1331                         if (sgl)
1332                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1333
1334                         if (buf) {
1335                                 memset(buf, 0, sgl->length);
1336                                 kunmap(sg_page(sgl));
1337                         }
1338                 }
1339
1340                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1341                                 sgl_bidi, sgl_bidi_count);
1342                 if (rc != 0) {
1343                         transport_generic_request_failure(se_cmd, rc);
1344                         return 0;
1345                 }
1346         }
1347         /*
1348          * Check if we need to delay processing because of ALUA
1349          * Active/NonOptimized primary access state..
1350          */
1351         core_alua_check_nonop_delay(se_cmd);
1352
1353         transport_handle_cdb_direct(se_cmd);
1354         return 0;
1355 }
1356 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1357
1358 /*
1359  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1360  *
1361  * @se_cmd: command descriptor to submit
1362  * @se_sess: associated se_sess for endpoint
1363  * @cdb: pointer to SCSI CDB
1364  * @sense: pointer to SCSI sense buffer
1365  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1366  * @data_length: fabric expected data transfer length
1367  * @task_addr: SAM task attribute
1368  * @data_dir: DMA data direction
1369  * @flags: flags for command submission from target_sc_flags_tables
1370  *
1371  * Returns non zero to signal active I/O shutdown failure.  All other
1372  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1373  * but still return zero here.
1374  *
1375  * This may only be called from process context, and also currently
1376  * assumes internal allocation of fabric payload buffer by target-core.
1377  *
1378  * It also assumes interal target core SGL memory allocation.
1379  */
1380 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1381                 unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1382                 u32 data_length, int task_attr, int data_dir, int flags)
1383 {
1384         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1385                         unpacked_lun, data_length, task_attr, data_dir,
1386                         flags, NULL, 0, NULL, 0);
1387 }
1388 EXPORT_SYMBOL(target_submit_cmd);
1389
1390 static void target_complete_tmr_failure(struct work_struct *work)
1391 {
1392         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1393
1394         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1395         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1396
1397         transport_cmd_check_stop_to_fabric(se_cmd);
1398 }
1399
1400 /**
1401  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1402  *                     for TMR CDBs
1403  *
1404  * @se_cmd: command descriptor to submit
1405  * @se_sess: associated se_sess for endpoint
1406  * @sense: pointer to SCSI sense buffer
1407  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1408  * @fabric_context: fabric context for TMR req
1409  * @tm_type: Type of TM request
1410  * @gfp: gfp type for caller
1411  * @tag: referenced task tag for TMR_ABORT_TASK
1412  * @flags: submit cmd flags
1413  *
1414  * Callable from all contexts.
1415  **/
1416
1417 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1418                 unsigned char *sense, u32 unpacked_lun,
1419                 void *fabric_tmr_ptr, unsigned char tm_type,
1420                 gfp_t gfp, unsigned int tag, int flags)
1421 {
1422         struct se_portal_group *se_tpg;
1423         int ret;
1424
1425         se_tpg = se_sess->se_tpg;
1426         BUG_ON(!se_tpg);
1427
1428         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1429                               0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1430         /*
1431          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1432          * allocation failure.
1433          */
1434         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1435         if (ret < 0)
1436                 return -ENOMEM;
1437
1438         if (tm_type == TMR_ABORT_TASK)
1439                 se_cmd->se_tmr_req->ref_task_tag = tag;
1440
1441         /* See target_submit_cmd for commentary */
1442         ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1443         if (ret) {
1444                 core_tmr_release_req(se_cmd->se_tmr_req);
1445                 return ret;
1446         }
1447
1448         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1449         if (ret) {
1450                 /*
1451                  * For callback during failure handling, push this work off
1452                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1453                  */
1454                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1455                 schedule_work(&se_cmd->work);
1456                 return 0;
1457         }
1458         transport_generic_handle_tmr(se_cmd);
1459         return 0;
1460 }
1461 EXPORT_SYMBOL(target_submit_tmr);
1462
1463 /*
1464  * If the cmd is active, request it to be stopped and sleep until it
1465  * has completed.
1466  */
1467 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1468 {
1469         bool was_active = false;
1470
1471         if (cmd->transport_state & CMD_T_BUSY) {
1472                 cmd->transport_state |= CMD_T_REQUEST_STOP;
1473                 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1474
1475                 pr_debug("cmd %p waiting to complete\n", cmd);
1476                 wait_for_completion(&cmd->task_stop_comp);
1477                 pr_debug("cmd %p stopped successfully\n", cmd);
1478
1479                 spin_lock_irqsave(&cmd->t_state_lock, *flags);
1480                 cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1481                 cmd->transport_state &= ~CMD_T_BUSY;
1482                 was_active = true;
1483         }
1484
1485         return was_active;
1486 }
1487
1488 /*
1489  * Handle SAM-esque emulation for generic transport request failures.
1490  */
1491 void transport_generic_request_failure(struct se_cmd *cmd,
1492                 sense_reason_t sense_reason)
1493 {
1494         int ret = 0;
1495
1496         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1497                 " CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1498                 cmd->t_task_cdb[0]);
1499         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1500                 cmd->se_tfo->get_cmd_state(cmd),
1501                 cmd->t_state, sense_reason);
1502         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1503                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1504                 (cmd->transport_state & CMD_T_STOP) != 0,
1505                 (cmd->transport_state & CMD_T_SENT) != 0);
1506
1507         /*
1508          * For SAM Task Attribute emulation for failed struct se_cmd
1509          */
1510         transport_complete_task_attr(cmd);
1511
1512         switch (sense_reason) {
1513         case TCM_NON_EXISTENT_LUN:
1514         case TCM_UNSUPPORTED_SCSI_OPCODE:
1515         case TCM_INVALID_CDB_FIELD:
1516         case TCM_INVALID_PARAMETER_LIST:
1517         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1518         case TCM_UNKNOWN_MODE_PAGE:
1519         case TCM_WRITE_PROTECTED:
1520         case TCM_ADDRESS_OUT_OF_RANGE:
1521         case TCM_CHECK_CONDITION_ABORT_CMD:
1522         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1523         case TCM_CHECK_CONDITION_NOT_READY:
1524                 break;
1525         case TCM_OUT_OF_RESOURCES:
1526                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1527                 break;
1528         case TCM_RESERVATION_CONFLICT:
1529                 /*
1530                  * No SENSE Data payload for this case, set SCSI Status
1531                  * and queue the response to $FABRIC_MOD.
1532                  *
1533                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1534                  */
1535                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1536                 /*
1537                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1538                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1539                  * CONFLICT STATUS.
1540                  *
1541                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1542                  */
1543                 if (cmd->se_sess &&
1544                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1545                         core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1546                                 cmd->orig_fe_lun, 0x2C,
1547                                 ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1548
1549                 ret = cmd->se_tfo->queue_status(cmd);
1550                 if (ret == -EAGAIN || ret == -ENOMEM)
1551                         goto queue_full;
1552                 goto check_stop;
1553         default:
1554                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1555                         cmd->t_task_cdb[0], sense_reason);
1556                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1557                 break;
1558         }
1559
1560         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1561         if (ret == -EAGAIN || ret == -ENOMEM)
1562                 goto queue_full;
1563
1564 check_stop:
1565         transport_lun_remove_cmd(cmd);
1566         if (!transport_cmd_check_stop_to_fabric(cmd))
1567                 ;
1568         return;
1569
1570 queue_full:
1571         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1572         transport_handle_queue_full(cmd, cmd->se_dev);
1573 }
1574 EXPORT_SYMBOL(transport_generic_request_failure);
1575
1576 static void __target_execute_cmd(struct se_cmd *cmd)
1577 {
1578         sense_reason_t ret;
1579
1580         spin_lock_irq(&cmd->t_state_lock);
1581         cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
1582         spin_unlock_irq(&cmd->t_state_lock);
1583
1584         if (cmd->execute_cmd) {
1585                 ret = cmd->execute_cmd(cmd);
1586                 if (ret) {
1587                         spin_lock_irq(&cmd->t_state_lock);
1588                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1589                         spin_unlock_irq(&cmd->t_state_lock);
1590
1591                         transport_generic_request_failure(cmd, ret);
1592                 }
1593         }
1594 }
1595
1596 static bool target_handle_task_attr(struct se_cmd *cmd)
1597 {
1598         struct se_device *dev = cmd->se_dev;
1599
1600         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1601                 return false;
1602
1603         /*
1604          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1605          * to allow the passed struct se_cmd list of tasks to the front of the list.
1606          */
1607         switch (cmd->sam_task_attr) {
1608         case MSG_HEAD_TAG:
1609                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1610                          "se_ordered_id: %u\n",
1611                          cmd->t_task_cdb[0], cmd->se_ordered_id);
1612                 return false;
1613         case MSG_ORDERED_TAG:
1614                 atomic_inc(&dev->dev_ordered_sync);
1615                 smp_mb__after_atomic_inc();
1616
1617                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1618                          " se_ordered_id: %u\n",
1619                          cmd->t_task_cdb[0], cmd->se_ordered_id);
1620
1621                 /*
1622                  * Execute an ORDERED command if no other older commands
1623                  * exist that need to be completed first.
1624                  */
1625                 if (!atomic_read(&dev->simple_cmds))
1626                         return false;
1627                 break;
1628         default:
1629                 /*
1630                  * For SIMPLE and UNTAGGED Task Attribute commands
1631                  */
1632                 atomic_inc(&dev->simple_cmds);
1633                 smp_mb__after_atomic_inc();
1634                 break;
1635         }
1636
1637         if (atomic_read(&dev->dev_ordered_sync) == 0)
1638                 return false;
1639
1640         spin_lock(&dev->delayed_cmd_lock);
1641         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1642         spin_unlock(&dev->delayed_cmd_lock);
1643
1644         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1645                 " delayed CMD list, se_ordered_id: %u\n",
1646                 cmd->t_task_cdb[0], cmd->sam_task_attr,
1647                 cmd->se_ordered_id);
1648         return true;
1649 }
1650
1651 void target_execute_cmd(struct se_cmd *cmd)
1652 {
1653         /*
1654          * If the received CDB has aleady been aborted stop processing it here.
1655          */
1656         if (transport_check_aborted_status(cmd, 1)) {
1657                 complete(&cmd->transport_lun_stop_comp);
1658                 return;
1659         }
1660
1661         /*
1662          * Determine if IOCTL context caller in requesting the stopping of this
1663          * command for LUN shutdown purposes.
1664          */
1665         spin_lock_irq(&cmd->t_state_lock);
1666         if (cmd->transport_state & CMD_T_LUN_STOP) {
1667                 pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
1668                         __func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
1669
1670                 cmd->transport_state &= ~CMD_T_ACTIVE;
1671                 spin_unlock_irq(&cmd->t_state_lock);
1672                 complete(&cmd->transport_lun_stop_comp);
1673                 return;
1674         }
1675         /*
1676          * Determine if frontend context caller is requesting the stopping of
1677          * this command for frontend exceptions.
1678          */
1679         if (cmd->transport_state & CMD_T_STOP) {
1680                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1681                         __func__, __LINE__,
1682                         cmd->se_tfo->get_task_tag(cmd));
1683
1684                 spin_unlock_irq(&cmd->t_state_lock);
1685                 complete(&cmd->t_transport_stop_comp);
1686                 return;
1687         }
1688
1689         cmd->t_state = TRANSPORT_PROCESSING;
1690         cmd->transport_state |= CMD_T_ACTIVE;
1691         spin_unlock_irq(&cmd->t_state_lock);
1692
1693         if (!target_handle_task_attr(cmd))
1694                 __target_execute_cmd(cmd);
1695 }
1696 EXPORT_SYMBOL(target_execute_cmd);
1697
1698 /*
1699  * Process all commands up to the last received ORDERED task attribute which
1700  * requires another blocking boundary
1701  */
1702 static void target_restart_delayed_cmds(struct se_device *dev)
1703 {
1704         for (;;) {
1705                 struct se_cmd *cmd;
1706
1707                 spin_lock(&dev->delayed_cmd_lock);
1708                 if (list_empty(&dev->delayed_cmd_list)) {
1709                         spin_unlock(&dev->delayed_cmd_lock);
1710                         break;
1711                 }
1712
1713                 cmd = list_entry(dev->delayed_cmd_list.next,
1714                                  struct se_cmd, se_delayed_node);
1715                 list_del(&cmd->se_delayed_node);
1716                 spin_unlock(&dev->delayed_cmd_lock);
1717
1718                 __target_execute_cmd(cmd);
1719
1720                 if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1721                         break;
1722         }
1723 }
1724
1725 /*
1726  * Called from I/O completion to determine which dormant/delayed
1727  * and ordered cmds need to have their tasks added to the execution queue.
1728  */
1729 static void transport_complete_task_attr(struct se_cmd *cmd)
1730 {
1731         struct se_device *dev = cmd->se_dev;
1732
1733         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1734                 return;
1735
1736         if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1737                 atomic_dec(&dev->simple_cmds);
1738                 smp_mb__after_atomic_dec();
1739                 dev->dev_cur_ordered_id++;
1740                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1741                         " SIMPLE: %u\n", dev->dev_cur_ordered_id,
1742                         cmd->se_ordered_id);
1743         } else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1744                 dev->dev_cur_ordered_id++;
1745                 pr_debug("Incremented dev_cur_ordered_id: %u for"
1746                         " HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1747                         cmd->se_ordered_id);
1748         } else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1749                 atomic_dec(&dev->dev_ordered_sync);
1750                 smp_mb__after_atomic_dec();
1751
1752                 dev->dev_cur_ordered_id++;
1753                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1754                         " %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1755         }
1756
1757         target_restart_delayed_cmds(dev);
1758 }
1759
1760 static void transport_complete_qf(struct se_cmd *cmd)
1761 {
1762         int ret = 0;
1763
1764         transport_complete_task_attr(cmd);
1765
1766         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1767                 ret = cmd->se_tfo->queue_status(cmd);
1768                 if (ret)
1769                         goto out;
1770         }
1771
1772         switch (cmd->data_direction) {
1773         case DMA_FROM_DEVICE:
1774                 ret = cmd->se_tfo->queue_data_in(cmd);
1775                 break;
1776         case DMA_TO_DEVICE:
1777                 if (cmd->t_bidi_data_sg) {
1778                         ret = cmd->se_tfo->queue_data_in(cmd);
1779                         if (ret < 0)
1780                                 break;
1781                 }
1782                 /* Fall through for DMA_TO_DEVICE */
1783         case DMA_NONE:
1784                 ret = cmd->se_tfo->queue_status(cmd);
1785                 break;
1786         default:
1787                 break;
1788         }
1789
1790 out:
1791         if (ret < 0) {
1792                 transport_handle_queue_full(cmd, cmd->se_dev);
1793                 return;
1794         }
1795         transport_lun_remove_cmd(cmd);
1796         transport_cmd_check_stop_to_fabric(cmd);
1797 }
1798
1799 static void transport_handle_queue_full(
1800         struct se_cmd *cmd,
1801         struct se_device *dev)
1802 {
1803         spin_lock_irq(&dev->qf_cmd_lock);
1804         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1805         atomic_inc(&dev->dev_qf_count);
1806         smp_mb__after_atomic_inc();
1807         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1808
1809         schedule_work(&cmd->se_dev->qf_work_queue);
1810 }
1811
1812 static void target_complete_ok_work(struct work_struct *work)
1813 {
1814         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1815         int ret;
1816
1817         /*
1818          * Check if we need to move delayed/dormant tasks from cmds on the
1819          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1820          * Attribute.
1821          */
1822         transport_complete_task_attr(cmd);
1823
1824         /*
1825          * Check to schedule QUEUE_FULL work, or execute an existing
1826          * cmd->transport_qf_callback()
1827          */
1828         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1829                 schedule_work(&cmd->se_dev->qf_work_queue);
1830
1831         /*
1832          * Check if we need to send a sense buffer from
1833          * the struct se_cmd in question.
1834          */
1835         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1836                 WARN_ON(!cmd->scsi_status);
1837                 ret = transport_send_check_condition_and_sense(
1838                                         cmd, 0, 1);
1839                 if (ret == -EAGAIN || ret == -ENOMEM)
1840                         goto queue_full;
1841
1842                 transport_lun_remove_cmd(cmd);
1843                 transport_cmd_check_stop_to_fabric(cmd);
1844                 return;
1845         }
1846         /*
1847          * Check for a callback, used by amongst other things
1848          * XDWRITE_READ_10 emulation.
1849          */
1850         if (cmd->transport_complete_callback)
1851                 cmd->transport_complete_callback(cmd);
1852
1853         switch (cmd->data_direction) {
1854         case DMA_FROM_DEVICE:
1855                 spin_lock(&cmd->se_lun->lun_sep_lock);
1856                 if (cmd->se_lun->lun_sep) {
1857                         cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1858                                         cmd->data_length;
1859                 }
1860                 spin_unlock(&cmd->se_lun->lun_sep_lock);
1861
1862                 ret = cmd->se_tfo->queue_data_in(cmd);
1863                 if (ret == -EAGAIN || ret == -ENOMEM)
1864                         goto queue_full;
1865                 break;
1866         case DMA_TO_DEVICE:
1867                 spin_lock(&cmd->se_lun->lun_sep_lock);
1868                 if (cmd->se_lun->lun_sep) {
1869                         cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
1870                                 cmd->data_length;
1871                 }
1872                 spin_unlock(&cmd->se_lun->lun_sep_lock);
1873                 /*
1874                  * Check if we need to send READ payload for BIDI-COMMAND
1875                  */
1876                 if (cmd->t_bidi_data_sg) {
1877                         spin_lock(&cmd->se_lun->lun_sep_lock);
1878                         if (cmd->se_lun->lun_sep) {
1879                                 cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1880                                         cmd->data_length;
1881                         }
1882                         spin_unlock(&cmd->se_lun->lun_sep_lock);
1883                         ret = cmd->se_tfo->queue_data_in(cmd);
1884                         if (ret == -EAGAIN || ret == -ENOMEM)
1885                                 goto queue_full;
1886                         break;
1887                 }
1888                 /* Fall through for DMA_TO_DEVICE */
1889         case DMA_NONE:
1890                 ret = cmd->se_tfo->queue_status(cmd);
1891                 if (ret == -EAGAIN || ret == -ENOMEM)
1892                         goto queue_full;
1893                 break;
1894         default:
1895                 break;
1896         }
1897
1898         transport_lun_remove_cmd(cmd);
1899         transport_cmd_check_stop_to_fabric(cmd);
1900         return;
1901
1902 queue_full:
1903         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
1904                 " data_direction: %d\n", cmd, cmd->data_direction);
1905         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1906         transport_handle_queue_full(cmd, cmd->se_dev);
1907 }
1908
1909 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
1910 {
1911         struct scatterlist *sg;
1912         int count;
1913
1914         for_each_sg(sgl, sg, nents, count)
1915                 __free_page(sg_page(sg));
1916
1917         kfree(sgl);
1918 }
1919
1920 static inline void transport_free_pages(struct se_cmd *cmd)
1921 {
1922         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
1923                 return;
1924
1925         transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
1926         cmd->t_data_sg = NULL;
1927         cmd->t_data_nents = 0;
1928
1929         transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
1930         cmd->t_bidi_data_sg = NULL;
1931         cmd->t_bidi_data_nents = 0;
1932 }
1933
1934 /**
1935  * transport_release_cmd - free a command
1936  * @cmd:       command to free
1937  *
1938  * This routine unconditionally frees a command, and reference counting
1939  * or list removal must be done in the caller.
1940  */
1941 static void transport_release_cmd(struct se_cmd *cmd)
1942 {
1943         BUG_ON(!cmd->se_tfo);
1944
1945         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1946                 core_tmr_release_req(cmd->se_tmr_req);
1947         if (cmd->t_task_cdb != cmd->__t_task_cdb)
1948                 kfree(cmd->t_task_cdb);
1949         /*
1950          * If this cmd has been setup with target_get_sess_cmd(), drop
1951          * the kref and call ->release_cmd() in kref callback.
1952          */
1953          if (cmd->check_release != 0) {
1954                 target_put_sess_cmd(cmd->se_sess, cmd);
1955                 return;
1956         }
1957         cmd->se_tfo->release_cmd(cmd);
1958 }
1959
1960 /**
1961  * transport_put_cmd - release a reference to a command
1962  * @cmd:       command to release
1963  *
1964  * This routine releases our reference to the command and frees it if possible.
1965  */
1966 static void transport_put_cmd(struct se_cmd *cmd)
1967 {
1968         unsigned long flags;
1969
1970         spin_lock_irqsave(&cmd->t_state_lock, flags);
1971         if (atomic_read(&cmd->t_fe_count) &&
1972             !atomic_dec_and_test(&cmd->t_fe_count)) {
1973                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1974                 return;
1975         }
1976
1977         if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
1978                 cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
1979                 target_remove_from_state_list(cmd);
1980         }
1981         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1982
1983         transport_free_pages(cmd);
1984         transport_release_cmd(cmd);
1985         return;
1986 }
1987
1988 void *transport_kmap_data_sg(struct se_cmd *cmd)
1989 {
1990         struct scatterlist *sg = cmd->t_data_sg;
1991         struct page **pages;
1992         int i;
1993
1994         /*
1995          * We need to take into account a possible offset here for fabrics like
1996          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
1997          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
1998          */
1999         if (!cmd->t_data_nents)
2000                 return NULL;
2001
2002         BUG_ON(!sg);
2003         if (cmd->t_data_nents == 1)
2004                 return kmap(sg_page(sg)) + sg->offset;
2005
2006         /* >1 page. use vmap */
2007         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2008         if (!pages)
2009                 return NULL;
2010
2011         /* convert sg[] to pages[] */
2012         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2013                 pages[i] = sg_page(sg);
2014         }
2015
2016         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2017         kfree(pages);
2018         if (!cmd->t_data_vmap)
2019                 return NULL;
2020
2021         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2022 }
2023 EXPORT_SYMBOL(transport_kmap_data_sg);
2024
2025 void transport_kunmap_data_sg(struct se_cmd *cmd)
2026 {
2027         if (!cmd->t_data_nents) {
2028                 return;
2029         } else if (cmd->t_data_nents == 1) {
2030                 kunmap(sg_page(cmd->t_data_sg));
2031                 return;
2032         }
2033
2034         vunmap(cmd->t_data_vmap);
2035         cmd->t_data_vmap = NULL;
2036 }
2037 EXPORT_SYMBOL(transport_kunmap_data_sg);
2038
2039 static int
2040 transport_generic_get_mem(struct se_cmd *cmd)
2041 {
2042         u32 length = cmd->data_length;
2043         unsigned int nents;
2044         struct page *page;
2045         gfp_t zero_flag;
2046         int i = 0;
2047
2048         nents = DIV_ROUND_UP(length, PAGE_SIZE);
2049         cmd->t_data_sg = kmalloc(sizeof(struct scatterlist) * nents, GFP_KERNEL);
2050         if (!cmd->t_data_sg)
2051                 return -ENOMEM;
2052
2053         cmd->t_data_nents = nents;
2054         sg_init_table(cmd->t_data_sg, nents);
2055
2056         zero_flag = cmd->se_cmd_flags & SCF_SCSI_DATA_CDB ? 0 : __GFP_ZERO;
2057
2058         while (length) {
2059                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2060                 page = alloc_page(GFP_KERNEL | zero_flag);
2061                 if (!page)
2062                         goto out;
2063
2064                 sg_set_page(&cmd->t_data_sg[i], page, page_len, 0);
2065                 length -= page_len;
2066                 i++;
2067         }
2068         return 0;
2069
2070 out:
2071         while (i > 0) {
2072                 i--;
2073                 __free_page(sg_page(&cmd->t_data_sg[i]));
2074         }
2075         kfree(cmd->t_data_sg);
2076         cmd->t_data_sg = NULL;
2077         return -ENOMEM;
2078 }
2079
2080 /*
2081  * Allocate any required resources to execute the command.  For writes we
2082  * might not have the payload yet, so notify the fabric via a call to
2083  * ->write_pending instead. Otherwise place it on the execution queue.
2084  */
2085 sense_reason_t
2086 transport_generic_new_cmd(struct se_cmd *cmd)
2087 {
2088         int ret = 0;
2089
2090         /*
2091          * Determine is the TCM fabric module has already allocated physical
2092          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2093          * beforehand.
2094          */
2095         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2096             cmd->data_length) {
2097                 ret = transport_generic_get_mem(cmd);
2098                 if (ret < 0)
2099                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2100         }
2101
2102         atomic_inc(&cmd->t_fe_count);
2103
2104         /*
2105          * If this command is not a write we can execute it right here,
2106          * for write buffers we need to notify the fabric driver first
2107          * and let it call back once the write buffers are ready.
2108          */
2109         target_add_to_state_list(cmd);
2110         if (cmd->data_direction != DMA_TO_DEVICE) {
2111                 target_execute_cmd(cmd);
2112                 return 0;
2113         }
2114
2115         spin_lock_irq(&cmd->t_state_lock);
2116         cmd->t_state = TRANSPORT_WRITE_PENDING;
2117         spin_unlock_irq(&cmd->t_state_lock);
2118
2119         transport_cmd_check_stop(cmd, false);
2120
2121         ret = cmd->se_tfo->write_pending(cmd);
2122         if (ret == -EAGAIN || ret == -ENOMEM)
2123                 goto queue_full;
2124
2125         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2126         WARN_ON(ret);
2127
2128         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2129
2130 queue_full:
2131         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2132         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2133         transport_handle_queue_full(cmd, cmd->se_dev);
2134         return 0;
2135 }
2136 EXPORT_SYMBOL(transport_generic_new_cmd);
2137
2138 static void transport_write_pending_qf(struct se_cmd *cmd)
2139 {
2140         int ret;
2141
2142         ret = cmd->se_tfo->write_pending(cmd);
2143         if (ret == -EAGAIN || ret == -ENOMEM) {
2144                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2145                          cmd);
2146                 transport_handle_queue_full(cmd, cmd->se_dev);
2147         }
2148 }
2149
2150 void transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2151 {
2152         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2153                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2154                          transport_wait_for_tasks(cmd);
2155
2156                 transport_release_cmd(cmd);
2157         } else {
2158                 if (wait_for_tasks)
2159                         transport_wait_for_tasks(cmd);
2160
2161                 core_dec_lacl_count(cmd->se_sess->se_node_acl, cmd);
2162
2163                 if (cmd->se_lun)
2164                         transport_lun_remove_cmd(cmd);
2165
2166                 transport_put_cmd(cmd);
2167         }
2168 }
2169 EXPORT_SYMBOL(transport_generic_free_cmd);
2170
2171 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2172  * @se_sess:    session to reference
2173  * @se_cmd:     command descriptor to add
2174  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2175  */
2176 static int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2177                                bool ack_kref)
2178 {
2179         unsigned long flags;
2180         int ret = 0;
2181
2182         kref_init(&se_cmd->cmd_kref);
2183         /*
2184          * Add a second kref if the fabric caller is expecting to handle
2185          * fabric acknowledgement that requires two target_put_sess_cmd()
2186          * invocations before se_cmd descriptor release.
2187          */
2188         if (ack_kref == true) {
2189                 kref_get(&se_cmd->cmd_kref);
2190                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2191         }
2192
2193         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2194         if (se_sess->sess_tearing_down) {
2195                 ret = -ESHUTDOWN;
2196                 goto out;
2197         }
2198         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2199         se_cmd->check_release = 1;
2200
2201 out:
2202         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2203         return ret;
2204 }
2205
2206 static void target_release_cmd_kref(struct kref *kref)
2207 {
2208         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2209         struct se_session *se_sess = se_cmd->se_sess;
2210         unsigned long flags;
2211
2212         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2213         if (list_empty(&se_cmd->se_cmd_list)) {
2214                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2215                 se_cmd->se_tfo->release_cmd(se_cmd);
2216                 return;
2217         }
2218         if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2219                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2220                 complete(&se_cmd->cmd_wait_comp);
2221                 return;
2222         }
2223         list_del(&se_cmd->se_cmd_list);
2224         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2225
2226         se_cmd->se_tfo->release_cmd(se_cmd);
2227 }
2228
2229 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2230  * @se_sess:    session to reference
2231  * @se_cmd:     command descriptor to drop
2232  */
2233 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2234 {
2235         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2236 }
2237 EXPORT_SYMBOL(target_put_sess_cmd);
2238
2239 /* target_sess_cmd_list_set_waiting - Flag all commands in
2240  *         sess_cmd_list to complete cmd_wait_comp.  Set
2241  *         sess_tearing_down so no more commands are queued.
2242  * @se_sess:    session to flag
2243  */
2244 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2245 {
2246         struct se_cmd *se_cmd;
2247         unsigned long flags;
2248
2249         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2250
2251         WARN_ON(se_sess->sess_tearing_down);
2252         se_sess->sess_tearing_down = 1;
2253
2254         list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list)
2255                 se_cmd->cmd_wait_set = 1;
2256
2257         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2258 }
2259 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2260
2261 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2262  * @se_sess:    session to wait for active I/O
2263  * @wait_for_tasks:     Make extra transport_wait_for_tasks call
2264  */
2265 void target_wait_for_sess_cmds(
2266         struct se_session *se_sess,
2267         int wait_for_tasks)
2268 {
2269         struct se_cmd *se_cmd, *tmp_cmd;
2270         bool rc = false;
2271
2272         list_for_each_entry_safe(se_cmd, tmp_cmd,
2273                                 &se_sess->sess_cmd_list, se_cmd_list) {
2274                 list_del(&se_cmd->se_cmd_list);
2275
2276                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2277                         " %d\n", se_cmd, se_cmd->t_state,
2278                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2279
2280                 if (wait_for_tasks) {
2281                         pr_debug("Calling transport_wait_for_tasks se_cmd: %p t_state: %d,"
2282                                 " fabric state: %d\n", se_cmd, se_cmd->t_state,
2283                                 se_cmd->se_tfo->get_cmd_state(se_cmd));
2284
2285                         rc = transport_wait_for_tasks(se_cmd);
2286
2287                         pr_debug("After transport_wait_for_tasks se_cmd: %p t_state: %d,"
2288                                 " fabric state: %d\n", se_cmd, se_cmd->t_state,
2289                                 se_cmd->se_tfo->get_cmd_state(se_cmd));
2290                 }
2291
2292                 if (!rc) {
2293                         wait_for_completion(&se_cmd->cmd_wait_comp);
2294                         pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2295                                 " fabric state: %d\n", se_cmd, se_cmd->t_state,
2296                                 se_cmd->se_tfo->get_cmd_state(se_cmd));
2297                 }
2298
2299                 se_cmd->se_tfo->release_cmd(se_cmd);
2300         }
2301 }
2302 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2303
2304 /*      transport_lun_wait_for_tasks():
2305  *
2306  *      Called from ConfigFS context to stop the passed struct se_cmd to allow
2307  *      an struct se_lun to be successfully shutdown.
2308  */
2309 static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
2310 {
2311         unsigned long flags;
2312         int ret = 0;
2313
2314         /*
2315          * If the frontend has already requested this struct se_cmd to
2316          * be stopped, we can safely ignore this struct se_cmd.
2317          */
2318         spin_lock_irqsave(&cmd->t_state_lock, flags);
2319         if (cmd->transport_state & CMD_T_STOP) {
2320                 cmd->transport_state &= ~CMD_T_LUN_STOP;
2321
2322                 pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
2323                          cmd->se_tfo->get_task_tag(cmd));
2324                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2325                 transport_cmd_check_stop(cmd, false);
2326                 return -EPERM;
2327         }
2328         cmd->transport_state |= CMD_T_LUN_FE_STOP;
2329         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2330
2331         // XXX: audit task_flags checks.
2332         spin_lock_irqsave(&cmd->t_state_lock, flags);
2333         if ((cmd->transport_state & CMD_T_BUSY) &&
2334             (cmd->transport_state & CMD_T_SENT)) {
2335                 if (!target_stop_cmd(cmd, &flags))
2336                         ret++;
2337         }
2338         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2339
2340         pr_debug("ConfigFS: cmd: %p stop tasks ret:"
2341                         " %d\n", cmd, ret);
2342         if (!ret) {
2343                 pr_debug("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
2344                                 cmd->se_tfo->get_task_tag(cmd));
2345                 wait_for_completion(&cmd->transport_lun_stop_comp);
2346                 pr_debug("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
2347                                 cmd->se_tfo->get_task_tag(cmd));
2348         }
2349
2350         return 0;
2351 }
2352
2353 static void __transport_clear_lun_from_sessions(struct se_lun *lun)
2354 {
2355         struct se_cmd *cmd = NULL;
2356         unsigned long lun_flags, cmd_flags;
2357         /*
2358          * Do exception processing and return CHECK_CONDITION status to the
2359          * Initiator Port.
2360          */
2361         spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2362         while (!list_empty(&lun->lun_cmd_list)) {
2363                 cmd = list_first_entry(&lun->lun_cmd_list,
2364                        struct se_cmd, se_lun_node);
2365                 list_del_init(&cmd->se_lun_node);
2366
2367                 spin_lock(&cmd->t_state_lock);
2368                 pr_debug("SE_LUN[%d] - Setting cmd->transport"
2369                         "_lun_stop for  ITT: 0x%08x\n",
2370                         cmd->se_lun->unpacked_lun,
2371                         cmd->se_tfo->get_task_tag(cmd));
2372                 cmd->transport_state |= CMD_T_LUN_STOP;
2373                 spin_unlock(&cmd->t_state_lock);
2374
2375                 spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2376
2377                 if (!cmd->se_lun) {
2378                         pr_err("ITT: 0x%08x, [i,t]_state: %u/%u\n",
2379                                 cmd->se_tfo->get_task_tag(cmd),
2380                                 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2381                         BUG();
2382                 }
2383                 /*
2384                  * If the Storage engine still owns the iscsi_cmd_t, determine
2385                  * and/or stop its context.
2386                  */
2387                 pr_debug("SE_LUN[%d] - ITT: 0x%08x before transport"
2388                         "_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
2389                         cmd->se_tfo->get_task_tag(cmd));
2390
2391                 if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
2392                         spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2393                         continue;
2394                 }
2395
2396                 pr_debug("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
2397                         "_wait_for_tasks(): SUCCESS\n",
2398                         cmd->se_lun->unpacked_lun,
2399                         cmd->se_tfo->get_task_tag(cmd));
2400
2401                 spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2402                 if (!(cmd->transport_state & CMD_T_DEV_ACTIVE)) {
2403                         spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2404                         goto check_cond;
2405                 }
2406                 cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2407                 target_remove_from_state_list(cmd);
2408                 spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2409
2410                 /*
2411                  * The Storage engine stopped this struct se_cmd before it was
2412                  * send to the fabric frontend for delivery back to the
2413                  * Initiator Node.  Return this SCSI CDB back with an
2414                  * CHECK_CONDITION status.
2415                  */
2416 check_cond:
2417                 transport_send_check_condition_and_sense(cmd,
2418                                 TCM_NON_EXISTENT_LUN, 0);
2419                 /*
2420                  *  If the fabric frontend is waiting for this iscsi_cmd_t to
2421                  * be released, notify the waiting thread now that LU has
2422                  * finished accessing it.
2423                  */
2424                 spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2425                 if (cmd->transport_state & CMD_T_LUN_FE_STOP) {
2426                         pr_debug("SE_LUN[%d] - Detected FE stop for"
2427                                 " struct se_cmd: %p ITT: 0x%08x\n",
2428                                 lun->unpacked_lun,
2429                                 cmd, cmd->se_tfo->get_task_tag(cmd));
2430
2431                         spin_unlock_irqrestore(&cmd->t_state_lock,
2432                                         cmd_flags);
2433                         transport_cmd_check_stop(cmd, false);
2434                         complete(&cmd->transport_lun_fe_stop_comp);
2435                         spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2436                         continue;
2437                 }
2438                 pr_debug("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
2439                         lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));
2440
2441                 spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2442                 spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2443         }
2444         spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2445 }
2446
2447 static int transport_clear_lun_thread(void *p)
2448 {
2449         struct se_lun *lun = p;
2450
2451         __transport_clear_lun_from_sessions(lun);
2452         complete(&lun->lun_shutdown_comp);
2453
2454         return 0;
2455 }
2456
2457 int transport_clear_lun_from_sessions(struct se_lun *lun)
2458 {
2459         struct task_struct *kt;
2460
2461         kt = kthread_run(transport_clear_lun_thread, lun,
2462                         "tcm_cl_%u", lun->unpacked_lun);
2463         if (IS_ERR(kt)) {
2464                 pr_err("Unable to start clear_lun thread\n");
2465                 return PTR_ERR(kt);
2466         }
2467         wait_for_completion(&lun->lun_shutdown_comp);
2468
2469         return 0;
2470 }
2471
2472 /**
2473  * transport_wait_for_tasks - wait for completion to occur
2474  * @cmd:        command to wait
2475  *
2476  * Called from frontend fabric context to wait for storage engine
2477  * to pause and/or release frontend generated struct se_cmd.
2478  */
2479 bool transport_wait_for_tasks(struct se_cmd *cmd)
2480 {
2481         unsigned long flags;
2482
2483         spin_lock_irqsave(&cmd->t_state_lock, flags);
2484         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2485             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2486                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2487                 return false;
2488         }
2489
2490         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2491             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2492                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2493                 return false;
2494         }
2495         /*
2496          * If we are already stopped due to an external event (ie: LUN shutdown)
2497          * sleep until the connection can have the passed struct se_cmd back.
2498          * The cmd->transport_lun_stopped_sem will be upped by
2499          * transport_clear_lun_from_sessions() once the ConfigFS context caller
2500          * has completed its operation on the struct se_cmd.
2501          */
2502         if (cmd->transport_state & CMD_T_LUN_STOP) {
2503                 pr_debug("wait_for_tasks: Stopping"
2504                         " wait_for_completion(&cmd->t_tasktransport_lun_fe"
2505                         "_stop_comp); for ITT: 0x%08x\n",
2506                         cmd->se_tfo->get_task_tag(cmd));
2507                 /*
2508                  * There is a special case for WRITES where a FE exception +
2509                  * LUN shutdown means ConfigFS context is still sleeping on
2510                  * transport_lun_stop_comp in transport_lun_wait_for_tasks().
2511                  * We go ahead and up transport_lun_stop_comp just to be sure
2512                  * here.
2513                  */
2514                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2515                 complete(&cmd->transport_lun_stop_comp);
2516                 wait_for_completion(&cmd->transport_lun_fe_stop_comp);
2517                 spin_lock_irqsave(&cmd->t_state_lock, flags);
2518
2519                 target_remove_from_state_list(cmd);
2520                 /*
2521                  * At this point, the frontend who was the originator of this
2522                  * struct se_cmd, now owns the structure and can be released through
2523                  * normal means below.
2524                  */
2525                 pr_debug("wait_for_tasks: Stopped"
2526                         " wait_for_completion(&cmd->t_tasktransport_lun_fe_"
2527                         "stop_comp); for ITT: 0x%08x\n",
2528                         cmd->se_tfo->get_task_tag(cmd));
2529
2530                 cmd->transport_state &= ~CMD_T_LUN_STOP;
2531         }
2532
2533         if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2534                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2535                 return false;
2536         }
2537
2538         cmd->transport_state |= CMD_T_STOP;
2539
2540         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2541                 " i_state: %d, t_state: %d, CMD_T_STOP\n",
2542                 cmd, cmd->se_tfo->get_task_tag(cmd),
2543                 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2544
2545         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2546
2547         wait_for_completion(&cmd->t_transport_stop_comp);
2548
2549         spin_lock_irqsave(&cmd->t_state_lock, flags);
2550         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2551
2552         pr_debug("wait_for_tasks: Stopped wait_for_completion("
2553                 "&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2554                 cmd->se_tfo->get_task_tag(cmd));
2555
2556         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2557
2558         return true;
2559 }
2560 EXPORT_SYMBOL(transport_wait_for_tasks);
2561
2562 static int transport_get_sense_codes(
2563         struct se_cmd *cmd,
2564         u8 *asc,
2565         u8 *ascq)
2566 {
2567         *asc = cmd->scsi_asc;
2568         *ascq = cmd->scsi_ascq;
2569
2570         return 0;
2571 }
2572
2573 int
2574 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2575                 sense_reason_t reason, int from_transport)
2576 {
2577         unsigned char *buffer = cmd->sense_buffer;
2578         unsigned long flags;
2579         u8 asc = 0, ascq = 0;
2580
2581         spin_lock_irqsave(&cmd->t_state_lock, flags);
2582         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2583                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2584                 return 0;
2585         }
2586         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2587         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2588
2589         if (!reason && from_transport)
2590                 goto after_reason;
2591
2592         if (!from_transport)
2593                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2594
2595         /*
2596          * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2597          * SENSE KEY values from include/scsi/scsi.h
2598          */
2599         switch (reason) {
2600         case TCM_NO_SENSE:
2601                 /* CURRENT ERROR */
2602                 buffer[0] = 0x70;
2603                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2604                 /* Not Ready */
2605                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2606                 /* NO ADDITIONAL SENSE INFORMATION */
2607                 buffer[SPC_ASC_KEY_OFFSET] = 0;
2608                 buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2609                 break;
2610         case TCM_NON_EXISTENT_LUN:
2611                 /* CURRENT ERROR */
2612                 buffer[0] = 0x70;
2613                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2614                 /* ILLEGAL REQUEST */
2615                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2616                 /* LOGICAL UNIT NOT SUPPORTED */
2617                 buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2618                 break;
2619         case TCM_UNSUPPORTED_SCSI_OPCODE:
2620         case TCM_SECTOR_COUNT_TOO_MANY:
2621                 /* CURRENT ERROR */
2622                 buffer[0] = 0x70;
2623                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2624                 /* ILLEGAL REQUEST */
2625                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2626                 /* INVALID COMMAND OPERATION CODE */
2627                 buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2628                 break;
2629         case TCM_UNKNOWN_MODE_PAGE:
2630                 /* CURRENT ERROR */
2631                 buffer[0] = 0x70;
2632                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2633                 /* ILLEGAL REQUEST */
2634                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2635                 /* INVALID FIELD IN CDB */
2636                 buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2637                 break;
2638         case TCM_CHECK_CONDITION_ABORT_CMD:
2639                 /* CURRENT ERROR */
2640                 buffer[0] = 0x70;
2641                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2642                 /* ABORTED COMMAND */
2643                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2644                 /* BUS DEVICE RESET FUNCTION OCCURRED */
2645                 buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2646                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2647                 break;
2648         case TCM_INCORRECT_AMOUNT_OF_DATA:
2649                 /* CURRENT ERROR */
2650                 buffer[0] = 0x70;
2651                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2652                 /* ABORTED COMMAND */
2653                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2654                 /* WRITE ERROR */
2655                 buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2656                 /* NOT ENOUGH UNSOLICITED DATA */
2657                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2658                 break;
2659         case TCM_INVALID_CDB_FIELD:
2660                 /* CURRENT ERROR */
2661                 buffer[0] = 0x70;
2662                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2663                 /* ILLEGAL REQUEST */
2664                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2665                 /* INVALID FIELD IN CDB */
2666                 buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2667                 break;
2668         case TCM_INVALID_PARAMETER_LIST:
2669                 /* CURRENT ERROR */
2670                 buffer[0] = 0x70;
2671                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2672                 /* ILLEGAL REQUEST */
2673                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2674                 /* INVALID FIELD IN PARAMETER LIST */
2675                 buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2676                 break;
2677         case TCM_UNEXPECTED_UNSOLICITED_DATA:
2678                 /* CURRENT ERROR */
2679                 buffer[0] = 0x70;
2680                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2681                 /* ABORTED COMMAND */
2682                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2683                 /* WRITE ERROR */
2684                 buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2685                 /* UNEXPECTED_UNSOLICITED_DATA */
2686                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2687                 break;
2688         case TCM_SERVICE_CRC_ERROR:
2689                 /* CURRENT ERROR */
2690                 buffer[0] = 0x70;
2691                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2692                 /* ABORTED COMMAND */
2693                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2694                 /* PROTOCOL SERVICE CRC ERROR */
2695                 buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2696                 /* N/A */
2697                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2698                 break;
2699         case TCM_SNACK_REJECTED:
2700                 /* CURRENT ERROR */
2701                 buffer[0] = 0x70;
2702                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2703                 /* ABORTED COMMAND */
2704                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2705                 /* READ ERROR */
2706                 buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2707                 /* FAILED RETRANSMISSION REQUEST */
2708                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2709                 break;
2710         case TCM_WRITE_PROTECTED:
2711                 /* CURRENT ERROR */
2712                 buffer[0] = 0x70;
2713                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2714                 /* DATA PROTECT */
2715                 buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2716                 /* WRITE PROTECTED */
2717                 buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2718                 break;
2719         case TCM_ADDRESS_OUT_OF_RANGE:
2720                 /* CURRENT ERROR */
2721                 buffer[0] = 0x70;
2722                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2723                 /* ILLEGAL REQUEST */
2724                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2725                 /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2726                 buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2727                 break;
2728         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2729                 /* CURRENT ERROR */
2730                 buffer[0] = 0x70;
2731                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2732                 /* UNIT ATTENTION */
2733                 buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2734                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2735                 buffer[SPC_ASC_KEY_OFFSET] = asc;
2736                 buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2737                 break;
2738         case TCM_CHECK_CONDITION_NOT_READY:
2739                 /* CURRENT ERROR */
2740                 buffer[0] = 0x70;
2741                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2742                 /* Not Ready */
2743                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2744                 transport_get_sense_codes(cmd, &asc, &ascq);
2745                 buffer[SPC_ASC_KEY_OFFSET] = asc;
2746                 buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2747                 break;
2748         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2749         default:
2750                 /* CURRENT ERROR */
2751                 buffer[0] = 0x70;
2752                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2753                 /* ILLEGAL REQUEST */
2754                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2755                 /* LOGICAL UNIT COMMUNICATION FAILURE */
2756                 buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2757                 break;
2758         }
2759         /*
2760          * This code uses linux/include/scsi/scsi.h SAM status codes!
2761          */
2762         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2763         /*
2764          * Automatically padded, this value is encoded in the fabric's
2765          * data_length response PDU containing the SCSI defined sense data.
2766          */
2767         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2768
2769 after_reason:
2770         return cmd->se_tfo->queue_status(cmd);
2771 }
2772 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2773
2774 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2775 {
2776         if (!(cmd->transport_state & CMD_T_ABORTED))
2777                 return 0;
2778
2779         if (!send_status || (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
2780                 return 1;
2781
2782         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2783                  cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2784
2785         cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
2786         cmd->se_tfo->queue_status(cmd);
2787
2788         return 1;
2789 }
2790 EXPORT_SYMBOL(transport_check_aborted_status);
2791
2792 void transport_send_task_abort(struct se_cmd *cmd)
2793 {
2794         unsigned long flags;
2795
2796         spin_lock_irqsave(&cmd->t_state_lock, flags);
2797         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION | SCF_SENT_DELAYED_TAS)) {
2798                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2799                 return;
2800         }
2801         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2802
2803         /*
2804          * If there are still expected incoming fabric WRITEs, we wait
2805          * until until they have completed before sending a TASK_ABORTED
2806          * response.  This response with TASK_ABORTED status will be
2807          * queued back to fabric module by transport_check_aborted_status().
2808          */
2809         if (cmd->data_direction == DMA_TO_DEVICE) {
2810                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2811                         cmd->transport_state |= CMD_T_ABORTED;
2812                         smp_mb__after_atomic_inc();
2813                 }
2814         }
2815         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2816
2817         transport_lun_remove_cmd(cmd);
2818
2819         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2820                 " ITT: 0x%08x\n", cmd->t_task_cdb[0],
2821                 cmd->se_tfo->get_task_tag(cmd));
2822
2823         cmd->se_tfo->queue_status(cmd);
2824 }
2825
2826 static void target_tmr_work(struct work_struct *work)
2827 {
2828         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2829         struct se_device *dev = cmd->se_dev;
2830         struct se_tmr_req *tmr = cmd->se_tmr_req;
2831         int ret;
2832
2833         switch (tmr->function) {
2834         case TMR_ABORT_TASK:
2835                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
2836                 break;
2837         case TMR_ABORT_TASK_SET:
2838         case TMR_CLEAR_ACA:
2839         case TMR_CLEAR_TASK_SET:
2840                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2841                 break;
2842         case TMR_LUN_RESET:
2843                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2844                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2845                                          TMR_FUNCTION_REJECTED;
2846                 break;
2847         case TMR_TARGET_WARM_RESET:
2848                 tmr->response = TMR_FUNCTION_REJECTED;
2849                 break;
2850         case TMR_TARGET_COLD_RESET:
2851                 tmr->response = TMR_FUNCTION_REJECTED;
2852                 break;
2853         default:
2854                 pr_err("Uknown TMR function: 0x%02x.\n",
2855                                 tmr->function);
2856                 tmr->response = TMR_FUNCTION_REJECTED;
2857                 break;
2858         }
2859
2860         cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2861         cmd->se_tfo->queue_tm_rsp(cmd);
2862
2863         transport_cmd_check_stop_to_fabric(cmd);
2864 }
2865
2866 int transport_generic_handle_tmr(
2867         struct se_cmd *cmd)
2868 {
2869         INIT_WORK(&cmd->work, target_tmr_work);
2870         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2871         return 0;
2872 }
2873 EXPORT_SYMBOL(transport_generic_handle_tmr);