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 2002-2013 Datera, Inc.
   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/spinlock.h>
  32 #include <linux/kthread.h>
  33 #include <linux/in.h>
  34 #include <linux/cdrom.h>
  35 #include <linux/module.h>
  36 #include <linux/ratelimit.h>
  37 #include <asm/unaligned.h>
  38 #include <net/sock.h>
  39 #include <net/tcp.h>
  40 #include <scsi/scsi.h>
  41 #include <scsi/scsi_cmnd.h>
  42 #include <scsi/scsi_tcq.h>
  43
  44 #include <target/target_core_base.h>
  45 #include <target/target_core_backend.h>
  46 #include <target/target_core_fabric.h>
  47 #include <target/target_core_configfs.h>
  48
  49 #include "target_core_internal.h"
  50 #include "target_core_alua.h"
  51 #include "target_core_pr.h"
  52 #include "target_core_ua.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/target.h>
  56
  57 static struct workqueue_struct *target_completion_wq;
  58 static struct kmem_cache *se_sess_cache;
  59 struct kmem_cache *se_ua_cache;
  60 struct kmem_cache *t10_pr_reg_cache;
  61 struct kmem_cache *t10_alua_lu_gp_cache;
  62 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  63 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  64 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
  65 struct kmem_cache *t10_alua_lba_map_cache;
  66 struct kmem_cache *t10_alua_lba_map_mem_cache;
  67
  68 static void transport_complete_task_attr(struct se_cmd *cmd);
  69 static void transport_handle_queue_full(struct se_cmd *cmd,
  70                 struct se_device *dev);
  71 static int transport_put_cmd(struct se_cmd *cmd);
  72 static void target_complete_ok_work(struct work_struct *work);
  73
  74 int init_se_kmem_caches(void)
  75 {
  76         se_sess_cache = kmem_cache_create("se_sess_cache",
  77                         sizeof(struct se_session), __alignof__(struct se_session),
  78                         0, NULL);
  79         if (!se_sess_cache) {
  80                 pr_err("kmem_cache_create() for struct se_session"
  81                                 " failed\n");
  82                 goto out;
  83         }
  84         se_ua_cache = kmem_cache_create("se_ua_cache",
  85                         sizeof(struct se_ua), __alignof__(struct se_ua),
  86                         0, NULL);
  87         if (!se_ua_cache) {
  88                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  89                 goto out_free_sess_cache;
  90         }
  91         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  92                         sizeof(struct t10_pr_registration),
  93                         __alignof__(struct t10_pr_registration), 0, NULL);
  94         if (!t10_pr_reg_cache) {
  95                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  96                                 " failed\n");
  97                 goto out_free_ua_cache;
  98         }
  99         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
 100                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
 101                         0, NULL);
 102         if (!t10_alua_lu_gp_cache) {
 103                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 104                                 " failed\n");
 105                 goto out_free_pr_reg_cache;
 106         }
 107         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 108                         sizeof(struct t10_alua_lu_gp_member),
 109                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 110         if (!t10_alua_lu_gp_mem_cache) {
 111                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 112                                 "cache failed\n");
 113                 goto out_free_lu_gp_cache;
 114         }
 115         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 116                         sizeof(struct t10_alua_tg_pt_gp),
 117                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 118         if (!t10_alua_tg_pt_gp_cache) {
 119                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 120                                 "cache failed\n");
 121                 goto out_free_lu_gp_mem_cache;
 122         }
 123         t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
 124                         "t10_alua_tg_pt_gp_mem_cache",
 125                         sizeof(struct t10_alua_tg_pt_gp_member),
 126                         __alignof__(struct t10_alua_tg_pt_gp_member),
 127                         0, NULL);
 128         if (!t10_alua_tg_pt_gp_mem_cache) {
 129                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 130                                 "mem_t failed\n");
 131                 goto out_free_tg_pt_gp_cache;
 132         }
 133         t10_alua_lba_map_cache = kmem_cache_create(
 134                         "t10_alua_lba_map_cache",
 135                         sizeof(struct t10_alua_lba_map),
 136                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 137         if (!t10_alua_lba_map_cache) {
 138                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 139                                 "cache failed\n");
 140                 goto out_free_tg_pt_gp_mem_cache;
 141         }
 142         t10_alua_lba_map_mem_cache = kmem_cache_create(
 143                         "t10_alua_lba_map_mem_cache",
 144                         sizeof(struct t10_alua_lba_map_member),
 145                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 146         if (!t10_alua_lba_map_mem_cache) {
 147                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 148                                 "cache failed\n");
 149                 goto out_free_lba_map_cache;
 150         }
 151
 152         target_completion_wq = alloc_workqueue("target_completion",
 153                                                WQ_MEM_RECLAIM, 0);
 154         if (!target_completion_wq)
 155                 goto out_free_lba_map_mem_cache;
 156
 157         return 0;
 158
 159 out_free_lba_map_mem_cache:
 160         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 161 out_free_lba_map_cache:
 162         kmem_cache_destroy(t10_alua_lba_map_cache);
 163 out_free_tg_pt_gp_mem_cache:
 164         kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 165 out_free_tg_pt_gp_cache:
 166         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 167 out_free_lu_gp_mem_cache:
 168         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 169 out_free_lu_gp_cache:
 170         kmem_cache_destroy(t10_alua_lu_gp_cache);
 171 out_free_pr_reg_cache:
 172         kmem_cache_destroy(t10_pr_reg_cache);
 173 out_free_ua_cache:
 174         kmem_cache_destroy(se_ua_cache);
 175 out_free_sess_cache:
 176         kmem_cache_destroy(se_sess_cache);
 177 out:
 178         return -ENOMEM;
 179 }
 180
 181 void release_se_kmem_caches(void)
 182 {
 183         destroy_workqueue(target_completion_wq);
 184         kmem_cache_destroy(se_sess_cache);
 185         kmem_cache_destroy(se_ua_cache);
 186         kmem_cache_destroy(t10_pr_reg_cache);
 187         kmem_cache_destroy(t10_alua_lu_gp_cache);
 188         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 189         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 190         kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 191         kmem_cache_destroy(t10_alua_lba_map_cache);
 192         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 193 }
 194
 195 /* This code ensures unique mib indexes are handed out. */
 196 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 197 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 198
 199 /*
 200  * Allocate a new row index for the entry type specified
 201  */
 202 u32 scsi_get_new_index(scsi_index_t type)
 203 {
 204         u32 new_index;
 205
 206         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 207
 208         spin_lock(&scsi_mib_index_lock);
 209         new_index = ++scsi_mib_index[type];
 210         spin_unlock(&scsi_mib_index_lock);
 211
 212         return new_index;
 213 }
 214
 215 void transport_subsystem_check_init(void)
 216 {
 217         int ret;
 218         static int sub_api_initialized;
 219
 220         if (sub_api_initialized)
 221                 return;
 222
 223         ret = request_module("target_core_iblock");
 224         if (ret != 0)
 225                 pr_err("Unable to load target_core_iblock\n");
 226
 227         ret = request_module("target_core_file");
 228         if (ret != 0)
 229                 pr_err("Unable to load target_core_file\n");
 230
 231         ret = request_module("target_core_pscsi");
 232         if (ret != 0)
 233                 pr_err("Unable to load target_core_pscsi\n");
 234
 235         sub_api_initialized = 1;
 236 }
 237
 238 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
 239 {
 240         struct se_session *se_sess;
 241
 242         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 243         if (!se_sess) {
 244                 pr_err("Unable to allocate struct se_session from"
 245                                 " se_sess_cache\n");
 246                 return ERR_PTR(-ENOMEM);
 247         }
 248         INIT_LIST_HEAD(&se_sess->sess_list);
 249         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 250         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 251         INIT_LIST_HEAD(&se_sess->sess_wait_list);
 252         spin_lock_init(&se_sess->sess_cmd_lock);
 253         kref_init(&se_sess->sess_kref);
 254         se_sess->sup_prot_ops = sup_prot_ops;
 255
 256         return se_sess;
 257 }
 258 EXPORT_SYMBOL(transport_init_session);
 259
 260 int transport_alloc_session_tags(struct se_session *se_sess,
 261                                  unsigned int tag_num, unsigned int tag_size)
 262 {
 263         int rc;
 264
 265         se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
 266                                         GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
 267         if (!se_sess->sess_cmd_map) {
 268                 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
 269                 if (!se_sess->sess_cmd_map) {
 270                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 271                         return -ENOMEM;
 272                 }
 273         }
 274
 275         rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
 276         if (rc < 0) {
 277                 pr_err("Unable to init se_sess->sess_tag_pool,"
 278                         " tag_num: %u\n", tag_num);
 279                 if (is_vmalloc_addr(se_sess->sess_cmd_map))
 280                         vfree(se_sess->sess_cmd_map);
 281                 else
 282                         kfree(se_sess->sess_cmd_map);
 283                 se_sess->sess_cmd_map = NULL;
 284                 return -ENOMEM;
 285         }
 286
 287         return 0;
 288 }
 289 EXPORT_SYMBOL(transport_alloc_session_tags);
 290
 291 struct se_session *transport_init_session_tags(unsigned int tag_num,
 292                                                unsigned int tag_size,
 293                                                enum target_prot_op sup_prot_ops)
 294 {
 295         struct se_session *se_sess;
 296         int rc;
 297
 298         se_sess = transport_init_session(sup_prot_ops);
 299         if (IS_ERR(se_sess))
 300                 return se_sess;
 301
 302         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 303         if (rc < 0) {
 304                 transport_free_session(se_sess);
 305                 return ERR_PTR(-ENOMEM);
 306         }
 307
 308         return se_sess;
 309 }
 310 EXPORT_SYMBOL(transport_init_session_tags);
 311
 312 /*
 313  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 314  */
 315 void __transport_register_session(
 316         struct se_portal_group *se_tpg,
 317         struct se_node_acl *se_nacl,
 318         struct se_session *se_sess,
 319         void *fabric_sess_ptr)
 320 {
 321         unsigned char buf[PR_REG_ISID_LEN];
 322
 323         se_sess->se_tpg = se_tpg;
 324         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 325         /*
 326          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 327          *
 328          * Only set for struct se_session's that will actually be moving I/O.
 329          * eg: *NOT* discovery sessions.
 330          */
 331         if (se_nacl) {
 332                 /*
 333                  * If the fabric module supports an ISID based TransportID,
 334                  * save this value in binary from the fabric I_T Nexus now.
 335                  */
 336                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 337                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 338                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 339                                         &buf[0], PR_REG_ISID_LEN);
 340                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 341                 }
 342                 kref_get(&se_nacl->acl_kref);
 343
 344                 spin_lock_irq(&se_nacl->nacl_sess_lock);
 345                 /*
 346                  * The se_nacl->nacl_sess pointer will be set to the
 347                  * last active I_T Nexus for each struct se_node_acl.
 348                  */
 349                 se_nacl->nacl_sess = se_sess;
 350
 351                 list_add_tail(&se_sess->sess_acl_list,
 352                               &se_nacl->acl_sess_list);
 353                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
 354         }
 355         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 356
 357         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 358                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 359 }
 360 EXPORT_SYMBOL(__transport_register_session);
 361
 362 void transport_register_session(
 363         struct se_portal_group *se_tpg,
 364         struct se_node_acl *se_nacl,
 365         struct se_session *se_sess,
 366         void *fabric_sess_ptr)
 367 {
 368         unsigned long flags;
 369
 370         spin_lock_irqsave(&se_tpg->session_lock, flags);
 371         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 372         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 373 }
 374 EXPORT_SYMBOL(transport_register_session);
 375
 376 static void target_release_session(struct kref *kref)
 377 {
 378         struct se_session *se_sess = container_of(kref,
 379                         struct se_session, sess_kref);
 380         struct se_portal_group *se_tpg = se_sess->se_tpg;
 381
 382         se_tpg->se_tpg_tfo->close_session(se_sess);
 383 }
 384
 385 void target_get_session(struct se_session *se_sess)
 386 {
 387         kref_get(&se_sess->sess_kref);
 388 }
 389 EXPORT_SYMBOL(target_get_session);
 390
 391 void target_put_session(struct se_session *se_sess)
 392 {
 393         struct se_portal_group *tpg = se_sess->se_tpg;
 394
 395         if (tpg->se_tpg_tfo->put_session != NULL) {
 396                 tpg->se_tpg_tfo->put_session(se_sess);
 397                 return;
 398         }
 399         kref_put(&se_sess->sess_kref, target_release_session);
 400 }
 401 EXPORT_SYMBOL(target_put_session);
 402
 403 static void target_complete_nacl(struct kref *kref)
 404 {
 405         struct se_node_acl *nacl = container_of(kref,
 406                                 struct se_node_acl, acl_kref);
 407
 408         complete(&nacl->acl_free_comp);
 409 }
 410
 411 void target_put_nacl(struct se_node_acl *nacl)
 412 {
 413         kref_put(&nacl->acl_kref, target_complete_nacl);
 414 }
 415
 416 void transport_deregister_session_configfs(struct se_session *se_sess)
 417 {
 418         struct se_node_acl *se_nacl;
 419         unsigned long flags;
 420         /*
 421          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 422          */
 423         se_nacl = se_sess->se_node_acl;
 424         if (se_nacl) {
 425                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 426                 if (se_nacl->acl_stop == 0)
 427                         list_del(&se_sess->sess_acl_list);
 428                 /*
 429                  * If the session list is empty, then clear the pointer.
 430                  * Otherwise, set the struct se_session pointer from the tail
 431                  * element of the per struct se_node_acl active session list.
 432                  */
 433                 if (list_empty(&se_nacl->acl_sess_list))
 434                         se_nacl->nacl_sess = NULL;
 435                 else {
 436                         se_nacl->nacl_sess = container_of(
 437                                         se_nacl->acl_sess_list.prev,
 438                                         struct se_session, sess_acl_list);
 439                 }
 440                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 441         }
 442 }
 443 EXPORT_SYMBOL(transport_deregister_session_configfs);
 444
 445 void transport_free_session(struct se_session *se_sess)
 446 {
 447         if (se_sess->sess_cmd_map) {
 448                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 449                 if (is_vmalloc_addr(se_sess->sess_cmd_map))
 450                         vfree(se_sess->sess_cmd_map);
 451                 else
 452                         kfree(se_sess->sess_cmd_map);
 453         }
 454         kmem_cache_free(se_sess_cache, se_sess);
 455 }
 456 EXPORT_SYMBOL(transport_free_session);
 457
 458 void transport_deregister_session(struct se_session *se_sess)
 459 {
 460         struct se_portal_group *se_tpg = se_sess->se_tpg;
 461         struct target_core_fabric_ops *se_tfo;
 462         struct se_node_acl *se_nacl;
 463         unsigned long flags;
 464         bool comp_nacl = true;
 465
 466         if (!se_tpg) {
 467                 transport_free_session(se_sess);
 468                 return;
 469         }
 470         se_tfo = se_tpg->se_tpg_tfo;
 471
 472         spin_lock_irqsave(&se_tpg->session_lock, flags);
 473         list_del(&se_sess->sess_list);
 474         se_sess->se_tpg = NULL;
 475         se_sess->fabric_sess_ptr = NULL;
 476         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 477
 478         /*
 479          * Determine if we need to do extra work for this initiator node's
 480          * struct se_node_acl if it had been previously dynamically generated.
 481          */
 482         se_nacl = se_sess->se_node_acl;
 483
 484         spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
 485         if (se_nacl && se_nacl->dynamic_node_acl) {
 486                 if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 487                         list_del(&se_nacl->acl_list);
 488                         se_tpg->num_node_acls--;
 489                         spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
 490                         core_tpg_wait_for_nacl_pr_ref(se_nacl);
 491                         core_free_device_list_for_node(se_nacl, se_tpg);
 492                         se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
 493
 494                         comp_nacl = false;
 495                         spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
 496                 }
 497         }
 498         spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
 499
 500         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 501                 se_tpg->se_tpg_tfo->get_fabric_name());
 502         /*
 503          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 504          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 505          * removal context.
 506          */
 507         if (se_nacl && comp_nacl == true)
 508                 target_put_nacl(se_nacl);
 509
 510         transport_free_session(se_sess);
 511 }
 512 EXPORT_SYMBOL(transport_deregister_session);
 513
 514 /*
 515  * Called with cmd->t_state_lock held.
 516  */
 517 static void target_remove_from_state_list(struct se_cmd *cmd)
 518 {
 519         struct se_device *dev = cmd->se_dev;
 520         unsigned long flags;
 521
 522         if (!dev)
 523                 return;
 524
 525         if (cmd->transport_state & CMD_T_BUSY)
 526                 return;
 527
 528         spin_lock_irqsave(&dev->execute_task_lock, flags);
 529         if (cmd->state_active) {
 530                 list_del(&cmd->state_list);
 531                 cmd->state_active = false;
 532         }
 533         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 534 }
 535
 536 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 537                                     bool write_pending)
 538 {
 539         unsigned long flags;
 540
 541         spin_lock_irqsave(&cmd->t_state_lock, flags);
 542         if (write_pending)
 543                 cmd->t_state = TRANSPORT_WRITE_PENDING;
 544
 545         if (remove_from_lists) {
 546                 target_remove_from_state_list(cmd);
 547
 548                 /*
 549                  * Clear struct se_cmd->se_lun before the handoff to FE.
 550                  */
 551                 cmd->se_lun = NULL;
 552         }
 553
 554         /*
 555          * Determine if frontend context caller is requesting the stopping of
 556          * this command for frontend exceptions.
 557          */
 558         if (cmd->transport_state & CMD_T_STOP) {
 559                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
 560                         __func__, __LINE__,
 561                         cmd->se_tfo->get_task_tag(cmd));
 562
 563                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 564
 565                 complete(&cmd->t_transport_stop_comp);
 566                 return 1;
 567         }
 568
 569         cmd->transport_state &= ~CMD_T_ACTIVE;
 570         if (remove_from_lists) {
 571                 /*
 572                  * Some fabric modules like tcm_loop can release
 573                  * their internally allocated I/O reference now and
 574                  * struct se_cmd now.
 575                  *
 576                  * Fabric modules are expected to return '1' here if the
 577                  * se_cmd being passed is released at this point,
 578                  * or zero if not being released.
 579                  */
 580                 if (cmd->se_tfo->check_stop_free != NULL) {
 581                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 582                         return cmd->se_tfo->check_stop_free(cmd);
 583                 }
 584         }
 585
 586         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 587         return 0;
 588 }
 589
 590 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 591 {
 592         return transport_cmd_check_stop(cmd, true, false);
 593 }
 594
 595 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 596 {
 597         struct se_lun *lun = cmd->se_lun;
 598
 599         if (!lun)
 600                 return;
 601
 602         if (cmpxchg(&cmd->lun_ref_active, true, false))
 603                 percpu_ref_put(&lun->lun_ref);
 604 }
 605
 606 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 607 {
 608         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 609                 transport_lun_remove_cmd(cmd);
 610         /*
 611          * Allow the fabric driver to unmap any resources before
 612          * releasing the descriptor via TFO->release_cmd()
 613          */
 614         if (remove)
 615                 cmd->se_tfo->aborted_task(cmd);
 616
 617         if (transport_cmd_check_stop_to_fabric(cmd))
 618                 return;
 619         if (remove)
 620                 transport_put_cmd(cmd);
 621 }
 622
 623 static void target_complete_failure_work(struct work_struct *work)
 624 {
 625         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 626
 627         transport_generic_request_failure(cmd,
 628                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 629 }
 630
 631 /*
 632  * Used when asking transport to copy Sense Data from the underlying
 633  * Linux/SCSI struct scsi_cmnd
 634  */
 635 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 636 {
 637         struct se_device *dev = cmd->se_dev;
 638
 639         WARN_ON(!cmd->se_lun);
 640
 641         if (!dev)
 642                 return NULL;
 643
 644         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 645                 return NULL;
 646
 647         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 648
 649         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 650                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 651         return cmd->sense_buffer;
 652 }
 653
 654 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 655 {
 656         struct se_device *dev = cmd->se_dev;
 657         int success = scsi_status == GOOD;
 658         unsigned long flags;
 659
 660         cmd->scsi_status = scsi_status;
 661
 662
 663         spin_lock_irqsave(&cmd->t_state_lock, flags);
 664         cmd->transport_state &= ~CMD_T_BUSY;
 665
 666         if (dev && dev->transport->transport_complete) {
 667                 dev->transport->transport_complete(cmd,
 668                                 cmd->t_data_sg,
 669                                 transport_get_sense_buffer(cmd));
 670                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 671                         success = 1;
 672         }
 673
 674         /*
 675          * See if we are waiting to complete for an exception condition.
 676          */
 677         if (cmd->transport_state & CMD_T_REQUEST_STOP) {
 678                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 679                 complete(&cmd->task_stop_comp);
 680                 return;
 681         }
 682
 683         /*
 684          * Check for case where an explicit ABORT_TASK has been received
 685          * and transport_wait_for_tasks() will be waiting for completion..
 686          */
 687         if (cmd->transport_state & CMD_T_ABORTED &&
 688             cmd->transport_state & CMD_T_STOP) {
 689                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 690                 complete(&cmd->t_transport_stop_comp);
 691                 return;
 692         } else if (!success) {
 693                 INIT_WORK(&cmd->work, target_complete_failure_work);
 694         } else {
 695                 INIT_WORK(&cmd->work, target_complete_ok_work);
 696         }
 697
 698         cmd->t_state = TRANSPORT_COMPLETE;
 699         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 700         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 701
 702         queue_work(target_completion_wq, &cmd->work);
 703 }
 704 EXPORT_SYMBOL(target_complete_cmd);
 705
 706 static void target_add_to_state_list(struct se_cmd *cmd)
 707 {
 708         struct se_device *dev = cmd->se_dev;
 709         unsigned long flags;
 710
 711         spin_lock_irqsave(&dev->execute_task_lock, flags);
 712         if (!cmd->state_active) {
 713                 list_add_tail(&cmd->state_list, &dev->state_list);
 714                 cmd->state_active = true;
 715         }
 716         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 717 }
 718
 719 /*
 720  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 721  */
 722 static void transport_write_pending_qf(struct se_cmd *cmd);
 723 static void transport_complete_qf(struct se_cmd *cmd);
 724
 725 void target_qf_do_work(struct work_struct *work)
 726 {
 727         struct se_device *dev = container_of(work, struct se_device,
 728                                         qf_work_queue);
 729         LIST_HEAD(qf_cmd_list);
 730         struct se_cmd *cmd, *cmd_tmp;
 731
 732         spin_lock_irq(&dev->qf_cmd_lock);
 733         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 734         spin_unlock_irq(&dev->qf_cmd_lock);
 735
 736         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 737                 list_del(&cmd->se_qf_node);
 738                 atomic_dec(&dev->dev_qf_count);
 739                 smp_mb__after_atomic_dec();
 740
 741                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 742                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 743                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 744                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 745                         : "UNKNOWN");
 746
 747                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 748                         transport_write_pending_qf(cmd);
 749                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 750                         transport_complete_qf(cmd);
 751         }
 752 }
 753
 754 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 755 {
 756         switch (cmd->data_direction) {
 757         case DMA_NONE:
 758                 return "NONE";
 759         case DMA_FROM_DEVICE:
 760                 return "READ";
 761         case DMA_TO_DEVICE:
 762                 return "WRITE";
 763         case DMA_BIDIRECTIONAL:
 764                 return "BIDI";
 765         default:
 766                 break;
 767         }
 768
 769         return "UNKNOWN";
 770 }
 771
 772 void transport_dump_dev_state(
 773         struct se_device *dev,
 774         char *b,
 775         int *bl)
 776 {
 777         *bl += sprintf(b + *bl, "Status: ");
 778         if (dev->export_count)
 779                 *bl += sprintf(b + *bl, "ACTIVATED");
 780         else
 781                 *bl += sprintf(b + *bl, "DEACTIVATED");
 782
 783         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 784         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 785                 dev->dev_attrib.block_size,
 786                 dev->dev_attrib.hw_max_sectors);
 787         *bl += sprintf(b + *bl, "        ");
 788 }
 789
 790 void transport_dump_vpd_proto_id(
 791         struct t10_vpd *vpd,
 792         unsigned char *p_buf,
 793         int p_buf_len)
 794 {
 795         unsigned char buf[VPD_TMP_BUF_SIZE];
 796         int len;
 797
 798         memset(buf, 0, VPD_TMP_BUF_SIZE);
 799         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 800
 801         switch (vpd->protocol_identifier) {
 802         case 0x00:
 803                 sprintf(buf+len, "Fibre Channel\n");
 804                 break;
 805         case 0x10:
 806                 sprintf(buf+len, "Parallel SCSI\n");
 807                 break;
 808         case 0x20:
 809                 sprintf(buf+len, "SSA\n");
 810                 break;
 811         case 0x30:
 812                 sprintf(buf+len, "IEEE 1394\n");
 813                 break;
 814         case 0x40:
 815                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 816                                 " Protocol\n");
 817                 break;
 818         case 0x50:
 819                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 820                 break;
 821         case 0x60:
 822                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 823                 break;
 824         case 0x70:
 825                 sprintf(buf+len, "Automation/Drive Interface Transport"
 826                                 " Protocol\n");
 827                 break;
 828         case 0x80:
 829                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 830                 break;
 831         default:
 832                 sprintf(buf+len, "Unknown 0x%02x\n",
 833                                 vpd->protocol_identifier);
 834                 break;
 835         }
 836
 837         if (p_buf)
 838                 strncpy(p_buf, buf, p_buf_len);
 839         else
 840                 pr_debug("%s", buf);
 841 }
 842
 843 void
 844 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 845 {
 846         /*
 847          * Check if the Protocol Identifier Valid (PIV) bit is set..
 848          *
 849          * from spc3r23.pdf section 7.5.1
 850          */
 851          if (page_83[1] & 0x80) {
 852                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 853                 vpd->protocol_identifier_set = 1;
 854                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 855         }
 856 }
 857 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 858
 859 int transport_dump_vpd_assoc(
 860         struct t10_vpd *vpd,
 861         unsigned char *p_buf,
 862         int p_buf_len)
 863 {
 864         unsigned char buf[VPD_TMP_BUF_SIZE];
 865         int ret = 0;
 866         int len;
 867
 868         memset(buf, 0, VPD_TMP_BUF_SIZE);
 869         len = sprintf(buf, "T10 VPD Identifier Association: ");
 870
 871         switch (vpd->association) {
 872         case 0x00:
 873                 sprintf(buf+len, "addressed logical unit\n");
 874                 break;
 875         case 0x10:
 876                 sprintf(buf+len, "target port\n");
 877                 break;
 878         case 0x20:
 879                 sprintf(buf+len, "SCSI target device\n");
 880                 break;
 881         default:
 882                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 883                 ret = -EINVAL;
 884                 break;
 885         }
 886
 887         if (p_buf)
 888                 strncpy(p_buf, buf, p_buf_len);
 889         else
 890                 pr_debug("%s", buf);
 891
 892         return ret;
 893 }
 894
 895 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 896 {
 897         /*
 898          * The VPD identification association..
 899          *
 900          * from spc3r23.pdf Section 7.6.3.1 Table 297
 901          */
 902         vpd->association = (page_83[1] & 0x30);
 903         return transport_dump_vpd_assoc(vpd, NULL, 0);
 904 }
 905 EXPORT_SYMBOL(transport_set_vpd_assoc);
 906
 907 int transport_dump_vpd_ident_type(
 908         struct t10_vpd *vpd,
 909         unsigned char *p_buf,
 910         int p_buf_len)
 911 {
 912         unsigned char buf[VPD_TMP_BUF_SIZE];
 913         int ret = 0;
 914         int len;
 915
 916         memset(buf, 0, VPD_TMP_BUF_SIZE);
 917         len = sprintf(buf, "T10 VPD Identifier Type: ");
 918
 919         switch (vpd->device_identifier_type) {
 920         case 0x00:
 921                 sprintf(buf+len, "Vendor specific\n");
 922                 break;
 923         case 0x01:
 924                 sprintf(buf+len, "T10 Vendor ID based\n");
 925                 break;
 926         case 0x02:
 927                 sprintf(buf+len, "EUI-64 based\n");
 928                 break;
 929         case 0x03:
 930                 sprintf(buf+len, "NAA\n");
 931                 break;
 932         case 0x04:
 933                 sprintf(buf+len, "Relative target port identifier\n");
 934                 break;
 935         case 0x08:
 936                 sprintf(buf+len, "SCSI name string\n");
 937                 break;
 938         default:
 939                 sprintf(buf+len, "Unsupported: 0x%02x\n",
 940                                 vpd->device_identifier_type);
 941                 ret = -EINVAL;
 942                 break;
 943         }
 944
 945         if (p_buf) {
 946                 if (p_buf_len < strlen(buf)+1)
 947                         return -EINVAL;
 948                 strncpy(p_buf, buf, p_buf_len);
 949         } else {
 950                 pr_debug("%s", buf);
 951         }
 952
 953         return ret;
 954 }
 955
 956 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
 957 {
 958         /*
 959          * The VPD identifier type..
 960          *
 961          * from spc3r23.pdf Section 7.6.3.1 Table 298
 962          */
 963         vpd->device_identifier_type = (page_83[1] & 0x0f);
 964         return transport_dump_vpd_ident_type(vpd, NULL, 0);
 965 }
 966 EXPORT_SYMBOL(transport_set_vpd_ident_type);
 967
 968 int transport_dump_vpd_ident(
 969         struct t10_vpd *vpd,
 970         unsigned char *p_buf,
 971         int p_buf_len)
 972 {
 973         unsigned char buf[VPD_TMP_BUF_SIZE];
 974         int ret = 0;
 975
 976         memset(buf, 0, VPD_TMP_BUF_SIZE);
 977
 978         switch (vpd->device_identifier_code_set) {
 979         case 0x01: /* Binary */
 980                 snprintf(buf, sizeof(buf),
 981                         "T10 VPD Binary Device Identifier: %s\n",
 982                         &vpd->device_identifier[0]);
 983                 break;
 984         case 0x02: /* ASCII */
 985                 snprintf(buf, sizeof(buf),
 986                         "T10 VPD ASCII Device Identifier: %s\n",
 987                         &vpd->device_identifier[0]);
 988                 break;
 989         case 0x03: /* UTF-8 */
 990                 snprintf(buf, sizeof(buf),
 991                         "T10 VPD UTF-8 Device Identifier: %s\n",
 992                         &vpd->device_identifier[0]);
 993                 break;
 994         default:
 995                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
 996                         " 0x%02x", vpd->device_identifier_code_set);
 997                 ret = -EINVAL;
 998                 break;
 999         }
1000
1001         if (p_buf)
1002                 strncpy(p_buf, buf, p_buf_len);
1003         else
1004                 pr_debug("%s", buf);
1005
1006         return ret;
1007 }
1008
1009 int
1010 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1011 {
1012         static const char hex_str[] = "0123456789abcdef";
1013         int j = 0, i = 4; /* offset to start of the identifier */
1014
1015         /*
1016          * The VPD Code Set (encoding)
1017          *
1018          * from spc3r23.pdf Section 7.6.3.1 Table 296
1019          */
1020         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1021         switch (vpd->device_identifier_code_set) {
1022         case 0x01: /* Binary */
1023                 vpd->device_identifier[j++] =
1024                                 hex_str[vpd->device_identifier_type];
1025                 while (i < (4 + page_83[3])) {
1026                         vpd->device_identifier[j++] =
1027                                 hex_str[(page_83[i] & 0xf0) >> 4];
1028                         vpd->device_identifier[j++] =
1029                                 hex_str[page_83[i] & 0x0f];
1030                         i++;
1031                 }
1032                 break;
1033         case 0x02: /* ASCII */
1034         case 0x03: /* UTF-8 */
1035                 while (i < (4 + page_83[3]))
1036                         vpd->device_identifier[j++] = page_83[i++];
1037                 break;
1038         default:
1039                 break;
1040         }
1041
1042         return transport_dump_vpd_ident(vpd, NULL, 0);
1043 }
1044 EXPORT_SYMBOL(transport_set_vpd_ident);
1045
1046 sense_reason_t
1047 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1048 {
1049         struct se_device *dev = cmd->se_dev;
1050
1051         if (cmd->unknown_data_length) {
1052                 cmd->data_length = size;
1053         } else if (size != cmd->data_length) {
1054                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1055                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1056                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1057                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1058
1059                 if (cmd->data_direction == DMA_TO_DEVICE) {
1060                         pr_err("Rejecting underflow/overflow"
1061                                         " WRITE data\n");
1062                         return TCM_INVALID_CDB_FIELD;
1063                 }
1064                 /*
1065                  * Reject READ_* or WRITE_* with overflow/underflow for
1066                  * type SCF_SCSI_DATA_CDB.
1067                  */
1068                 if (dev->dev_attrib.block_size != 512)  {
1069                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1070                                 " CDB on non 512-byte sector setup subsystem"
1071                                 " plugin: %s\n", dev->transport->name);
1072                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1073                         return TCM_INVALID_CDB_FIELD;
1074                 }
1075                 /*
1076                  * For the overflow case keep the existing fabric provided
1077                  * ->data_length.  Otherwise for the underflow case, reset
1078                  * ->data_length to the smaller SCSI expected data transfer
1079                  * length.
1080                  */
1081                 if (size > cmd->data_length) {
1082                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1083                         cmd->residual_count = (size - cmd->data_length);
1084                 } else {
1085                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1086                         cmd->residual_count = (cmd->data_length - size);
1087                         cmd->data_length = size;
1088                 }
1089         }
1090
1091         return 0;
1092
1093 }
1094
1095 /*
1096  * Used by fabric modules containing a local struct se_cmd within their
1097  * fabric dependent per I/O descriptor.
1098  */
1099 void transport_init_se_cmd(
1100         struct se_cmd *cmd,
1101         struct target_core_fabric_ops *tfo,
1102         struct se_session *se_sess,
1103         u32 data_length,
1104         int data_direction,
1105         int task_attr,
1106         unsigned char *sense_buffer)
1107 {
1108         INIT_LIST_HEAD(&cmd->se_delayed_node);
1109         INIT_LIST_HEAD(&cmd->se_qf_node);
1110         INIT_LIST_HEAD(&cmd->se_cmd_list);
1111         INIT_LIST_HEAD(&cmd->state_list);
1112         init_completion(&cmd->t_transport_stop_comp);
1113         init_completion(&cmd->cmd_wait_comp);
1114         init_completion(&cmd->task_stop_comp);
1115         spin_lock_init(&cmd->t_state_lock);
1116         cmd->transport_state = CMD_T_DEV_ACTIVE;
1117
1118         cmd->se_tfo = tfo;
1119         cmd->se_sess = se_sess;
1120         cmd->data_length = data_length;
1121         cmd->data_direction = data_direction;
1122         cmd->sam_task_attr = task_attr;
1123         cmd->sense_buffer = sense_buffer;
1124
1125         cmd->state_active = false;
1126 }
1127 EXPORT_SYMBOL(transport_init_se_cmd);
1128
1129 static sense_reason_t
1130 transport_check_alloc_task_attr(struct se_cmd *cmd)
1131 {
1132         struct se_device *dev = cmd->se_dev;
1133
1134         /*
1135          * Check if SAM Task Attribute emulation is enabled for this
1136          * struct se_device storage object
1137          */
1138         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1139                 return 0;
1140
1141         if (cmd->sam_task_attr == MSG_ACA_TAG) {
1142                 pr_debug("SAM Task Attribute ACA"
1143                         " emulation is not supported\n");
1144                 return TCM_INVALID_CDB_FIELD;
1145         }
1146         /*
1147          * Used to determine when ORDERED commands should go from
1148          * Dormant to Active status.
1149          */
1150         cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1151         smp_mb__after_atomic_inc();
1152         pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1153                         cmd->se_ordered_id, cmd->sam_task_attr,
1154                         dev->transport->name);
1155         return 0;
1156 }
1157
1158 sense_reason_t
1159 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1160 {
1161         struct se_device *dev = cmd->se_dev;
1162         sense_reason_t ret;
1163
1164         /*
1165          * Ensure that the received CDB is less than the max (252 + 8) bytes
1166          * for VARIABLE_LENGTH_CMD
1167          */
1168         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1169                 pr_err("Received SCSI CDB with command_size: %d that"
1170                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1171                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1172                 return TCM_INVALID_CDB_FIELD;
1173         }
1174         /*
1175          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1176          * allocate the additional extended CDB buffer now..  Otherwise
1177          * setup the pointer from __t_task_cdb to t_task_cdb.
1178          */
1179         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1180                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1181                                                 GFP_KERNEL);
1182                 if (!cmd->t_task_cdb) {
1183                         pr_err("Unable to allocate cmd->t_task_cdb"
1184                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1185                                 scsi_command_size(cdb),
1186                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1187                         return TCM_OUT_OF_RESOURCES;
1188                 }
1189         } else
1190                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1191         /*
1192          * Copy the original CDB into cmd->
1193          */
1194         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1195
1196         trace_target_sequencer_start(cmd);
1197
1198         /*
1199          * Check for an existing UNIT ATTENTION condition
1200          */
1201         ret = target_scsi3_ua_check(cmd);
1202         if (ret)
1203                 return ret;
1204
1205         ret = target_alua_state_check(cmd);
1206         if (ret)
1207                 return ret;
1208
1209         ret = target_check_reservation(cmd);
1210         if (ret) {
1211                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1212                 return ret;
1213         }
1214
1215         ret = dev->transport->parse_cdb(cmd);
1216         if (ret)
1217                 return ret;
1218
1219         ret = transport_check_alloc_task_attr(cmd);
1220         if (ret)
1221                 return ret;
1222
1223         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1224
1225         spin_lock(&cmd->se_lun->lun_sep_lock);
1226         if (cmd->se_lun->lun_sep)
1227                 cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1228         spin_unlock(&cmd->se_lun->lun_sep_lock);
1229         return 0;
1230 }
1231 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1232
1233 /*
1234  * Used by fabric module frontends to queue tasks directly.
1235  * Many only be used from process context only
1236  */
1237 int transport_handle_cdb_direct(
1238         struct se_cmd *cmd)
1239 {
1240         sense_reason_t ret;
1241
1242         if (!cmd->se_lun) {
1243                 dump_stack();
1244                 pr_err("cmd->se_lun is NULL\n");
1245                 return -EINVAL;
1246         }
1247         if (in_interrupt()) {
1248                 dump_stack();
1249                 pr_err("transport_generic_handle_cdb cannot be called"
1250                                 " from interrupt context\n");
1251                 return -EINVAL;
1252         }
1253         /*
1254          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1255          * outstanding descriptors are handled correctly during shutdown via
1256          * transport_wait_for_tasks()
1257          *
1258          * Also, we don't take cmd->t_state_lock here as we only expect
1259          * this to be called for initial descriptor submission.
1260          */
1261         cmd->t_state = TRANSPORT_NEW_CMD;
1262         cmd->transport_state |= CMD_T_ACTIVE;
1263
1264         /*
1265          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1266          * so follow TRANSPORT_NEW_CMD processing thread context usage
1267          * and call transport_generic_request_failure() if necessary..
1268          */
1269         ret = transport_generic_new_cmd(cmd);
1270         if (ret)
1271                 transport_generic_request_failure(cmd, ret);
1272         return 0;
1273 }
1274 EXPORT_SYMBOL(transport_handle_cdb_direct);
1275
1276 sense_reason_t
1277 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1278                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1279 {
1280         if (!sgl || !sgl_count)
1281                 return 0;
1282
1283         /*
1284          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1285          * scatterlists already have been set to follow what the fabric
1286          * passes for the original expected data transfer length.
1287          */
1288         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1289                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1290                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1291                 return TCM_INVALID_CDB_FIELD;
1292         }
1293
1294         cmd->t_data_sg = sgl;
1295         cmd->t_data_nents = sgl_count;
1296
1297         if (sgl_bidi && sgl_bidi_count) {
1298                 cmd->t_bidi_data_sg = sgl_bidi;
1299                 cmd->t_bidi_data_nents = sgl_bidi_count;
1300         }
1301         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1302         return 0;
1303 }
1304
1305 /*
1306  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1307  *                       se_cmd + use pre-allocated SGL memory.
1308  *
1309  * @se_cmd: command descriptor to submit
1310  * @se_sess: associated se_sess for endpoint
1311  * @cdb: pointer to SCSI CDB
1312  * @sense: pointer to SCSI sense buffer
1313  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1314  * @data_length: fabric expected data transfer length
1315  * @task_addr: SAM task attribute
1316  * @data_dir: DMA data direction
1317  * @flags: flags for command submission from target_sc_flags_tables
1318  * @sgl: struct scatterlist memory for unidirectional mapping
1319  * @sgl_count: scatterlist count for unidirectional mapping
1320  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1321  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1322  * @sgl_prot: struct scatterlist memory protection information
1323  * @sgl_prot_count: scatterlist count for protection information
1324  *
1325  * Returns non zero to signal active I/O shutdown failure.  All other
1326  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1327  * but still return zero here.
1328  *
1329  * This may only be called from process context, and also currently
1330  * assumes internal allocation of fabric payload buffer by target-core.
1331  */
1332 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1333                 unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1334                 u32 data_length, int task_attr, int data_dir, int flags,
1335                 struct scatterlist *sgl, u32 sgl_count,
1336                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1337                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1338 {
1339         struct se_portal_group *se_tpg;
1340         sense_reason_t rc;
1341         int ret;
1342
1343         se_tpg = se_sess->se_tpg;
1344         BUG_ON(!se_tpg);
1345         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1346         BUG_ON(in_interrupt());
1347         /*
1348          * Initialize se_cmd for target operation.  From this point
1349          * exceptions are handled by sending exception status via
1350          * target_core_fabric_ops->queue_status() callback
1351          */
1352         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1353                                 data_length, data_dir, task_attr, sense);
1354         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1355                 se_cmd->unknown_data_length = 1;
1356         /*
1357          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1358          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1359          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1360          * kref_put() to happen during fabric packet acknowledgement.
1361          */
1362         ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1363         if (ret)
1364                 return ret;
1365         /*
1366          * Signal bidirectional data payloads to target-core
1367          */
1368         if (flags & TARGET_SCF_BIDI_OP)
1369                 se_cmd->se_cmd_flags |= SCF_BIDI;
1370         /*
1371          * Locate se_lun pointer and attach it to struct se_cmd
1372          */
1373         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1374         if (rc) {
1375                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1376                 target_put_sess_cmd(se_sess, se_cmd);
1377                 return 0;
1378         }
1379
1380         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1381         if (rc != 0) {
1382                 transport_generic_request_failure(se_cmd, rc);
1383                 return 0;
1384         }
1385
1386         /*
1387          * Save pointers for SGLs containing protection information,
1388          * if present.
1389          */
1390         if (sgl_prot_count) {
1391                 se_cmd->t_prot_sg = sgl_prot;
1392                 se_cmd->t_prot_nents = sgl_prot_count;
1393         }
1394
1395         /*
1396          * When a non zero sgl_count has been passed perform SGL passthrough
1397          * mapping for pre-allocated fabric memory instead of having target
1398          * core perform an internal SGL allocation..
1399          */
1400         if (sgl_count != 0) {
1401                 BUG_ON(!sgl);
1402
1403                 /*
1404                  * A work-around for tcm_loop as some userspace code via
1405                  * scsi-generic do not memset their associated read buffers,
1406                  * so go ahead and do that here for type non-data CDBs.  Also
1407                  * note that this is currently guaranteed to be a single SGL
1408                  * for this case by target core in target_setup_cmd_from_cdb()
1409                  * -> transport_generic_cmd_sequencer().
1410                  */
1411                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1412                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1413                         unsigned char *buf = NULL;
1414
1415                         if (sgl)
1416                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1417
1418                         if (buf) {
1419                                 memset(buf, 0, sgl->length);
1420                                 kunmap(sg_page(sgl));
1421                         }
1422                 }
1423
1424                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1425                                 sgl_bidi, sgl_bidi_count);
1426                 if (rc != 0) {
1427                         transport_generic_request_failure(se_cmd, rc);
1428                         return 0;
1429                 }
1430         }
1431
1432         /*
1433          * Check if we need to delay processing because of ALUA
1434          * Active/NonOptimized primary access state..
1435          */
1436         core_alua_check_nonop_delay(se_cmd);
1437
1438         transport_handle_cdb_direct(se_cmd);
1439         return 0;
1440 }
1441 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1442
1443 /*
1444  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1445  *
1446  * @se_cmd: command descriptor to submit
1447  * @se_sess: associated se_sess for endpoint
1448  * @cdb: pointer to SCSI CDB
1449  * @sense: pointer to SCSI sense buffer
1450  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1451  * @data_length: fabric expected data transfer length
1452  * @task_addr: SAM task attribute
1453  * @data_dir: DMA data direction
1454  * @flags: flags for command submission from target_sc_flags_tables
1455  *
1456  * Returns non zero to signal active I/O shutdown failure.  All other
1457  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1458  * but still return zero here.
1459  *
1460  * This may only be called from process context, and also currently
1461  * assumes internal allocation of fabric payload buffer by target-core.
1462  *
1463  * It also assumes interal target core SGL memory allocation.
1464  */
1465 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1466                 unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1467                 u32 data_length, int task_attr, int data_dir, int flags)
1468 {
1469         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1470                         unpacked_lun, data_length, task_attr, data_dir,
1471                         flags, NULL, 0, NULL, 0, NULL, 0);
1472 }
1473 EXPORT_SYMBOL(target_submit_cmd);
1474
1475 static void target_complete_tmr_failure(struct work_struct *work)
1476 {
1477         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1478
1479         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1480         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1481
1482         transport_cmd_check_stop_to_fabric(se_cmd);
1483 }
1484
1485 /**
1486  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1487  *                     for TMR CDBs
1488  *
1489  * @se_cmd: command descriptor to submit
1490  * @se_sess: associated se_sess for endpoint
1491  * @sense: pointer to SCSI sense buffer
1492  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1493  * @fabric_context: fabric context for TMR req
1494  * @tm_type: Type of TM request
1495  * @gfp: gfp type for caller
1496  * @tag: referenced task tag for TMR_ABORT_TASK
1497  * @flags: submit cmd flags
1498  *
1499  * Callable from all contexts.
1500  **/
1501
1502 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1503                 unsigned char *sense, u32 unpacked_lun,
1504                 void *fabric_tmr_ptr, unsigned char tm_type,
1505                 gfp_t gfp, unsigned int tag, int flags)
1506 {
1507         struct se_portal_group *se_tpg;
1508         int ret;
1509
1510         se_tpg = se_sess->se_tpg;
1511         BUG_ON(!se_tpg);
1512
1513         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1514                               0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1515         /*
1516          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1517          * allocation failure.
1518          */
1519         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1520         if (ret < 0)
1521                 return -ENOMEM;
1522
1523         if (tm_type == TMR_ABORT_TASK)
1524                 se_cmd->se_tmr_req->ref_task_tag = tag;
1525
1526         /* See target_submit_cmd for commentary */
1527         ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1528         if (ret) {
1529                 core_tmr_release_req(se_cmd->se_tmr_req);
1530                 return ret;
1531         }
1532
1533         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1534         if (ret) {
1535                 /*
1536                  * For callback during failure handling, push this work off
1537                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1538                  */
1539                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1540                 schedule_work(&se_cmd->work);
1541                 return 0;
1542         }
1543         transport_generic_handle_tmr(se_cmd);
1544         return 0;
1545 }
1546 EXPORT_SYMBOL(target_submit_tmr);
1547
1548 /*
1549  * If the cmd is active, request it to be stopped and sleep until it
1550  * has completed.
1551  */
1552 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1553 {
1554         bool was_active = false;
1555
1556         if (cmd->transport_state & CMD_T_BUSY) {
1557                 cmd->transport_state |= CMD_T_REQUEST_STOP;
1558                 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1559
1560                 pr_debug("cmd %p waiting to complete\n", cmd);
1561                 wait_for_completion(&cmd->task_stop_comp);
1562                 pr_debug("cmd %p stopped successfully\n", cmd);
1563
1564                 spin_lock_irqsave(&cmd->t_state_lock, *flags);
1565                 cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1566                 cmd->transport_state &= ~CMD_T_BUSY;
1567                 was_active = true;
1568         }
1569
1570         return was_active;
1571 }
1572
1573 /*
1574  * Handle SAM-esque emulation for generic transport request failures.
1575  */
1576 void transport_generic_request_failure(struct se_cmd *cmd,
1577                 sense_reason_t sense_reason)
1578 {
1579         int ret = 0;
1580
1581         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1582                 " CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1583                 cmd->t_task_cdb[0]);
1584         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1585                 cmd->se_tfo->get_cmd_state(cmd),
1586                 cmd->t_state, sense_reason);
1587         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1588                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1589                 (cmd->transport_state & CMD_T_STOP) != 0,
1590                 (cmd->transport_state & CMD_T_SENT) != 0);
1591
1592         /*
1593          * For SAM Task Attribute emulation for failed struct se_cmd
1594          */
1595         transport_complete_task_attr(cmd);
1596         /*
1597          * Handle special case for COMPARE_AND_WRITE failure, where the
1598          * callback is expected to drop the per device ->caw_mutex.
1599          */
1600         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1601              cmd->transport_complete_callback)
1602                 cmd->transport_complete_callback(cmd);
1603
1604         switch (sense_reason) {
1605         case TCM_NON_EXISTENT_LUN:
1606         case TCM_UNSUPPORTED_SCSI_OPCODE:
1607         case TCM_INVALID_CDB_FIELD:
1608         case TCM_INVALID_PARAMETER_LIST:
1609         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1610         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1611         case TCM_UNKNOWN_MODE_PAGE:
1612         case TCM_WRITE_PROTECTED:
1613         case TCM_ADDRESS_OUT_OF_RANGE:
1614         case TCM_CHECK_CONDITION_ABORT_CMD:
1615         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1616         case TCM_CHECK_CONDITION_NOT_READY:
1617         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1618         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1619         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1620                 break;
1621         case TCM_OUT_OF_RESOURCES:
1622                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1623                 break;
1624         case TCM_RESERVATION_CONFLICT:
1625                 /*
1626                  * No SENSE Data payload for this case, set SCSI Status
1627                  * and queue the response to $FABRIC_MOD.
1628                  *
1629                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1630                  */
1631                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1632                 /*
1633                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1634                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1635                  * CONFLICT STATUS.
1636                  *
1637                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1638                  */
1639                 if (cmd->se_sess &&
1640                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1641                         core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1642                                 cmd->orig_fe_lun, 0x2C,
1643                                 ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1644
1645                 trace_target_cmd_complete(cmd);
1646                 ret = cmd->se_tfo-> queue_status(cmd);
1647                 if (ret == -EAGAIN || ret == -ENOMEM)
1648                         goto queue_full;
1649                 goto check_stop;
1650         default:
1651                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1652                         cmd->t_task_cdb[0], sense_reason);
1653                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1654                 break;
1655         }
1656
1657         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1658         if (ret == -EAGAIN || ret == -ENOMEM)
1659                 goto queue_full;
1660
1661 check_stop:
1662         transport_lun_remove_cmd(cmd);
1663         if (!transport_cmd_check_stop_to_fabric(cmd))
1664                 ;
1665         return;
1666
1667 queue_full:
1668         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1669         transport_handle_queue_full(cmd, cmd->se_dev);
1670 }
1671 EXPORT_SYMBOL(transport_generic_request_failure);
1672
1673 void __target_execute_cmd(struct se_cmd *cmd)
1674 {
1675         sense_reason_t ret;
1676
1677         if (cmd->execute_cmd) {
1678                 ret = cmd->execute_cmd(cmd);
1679                 if (ret) {
1680                         spin_lock_irq(&cmd->t_state_lock);
1681                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1682                         spin_unlock_irq(&cmd->t_state_lock);
1683
1684                         transport_generic_request_failure(cmd, ret);
1685                 }
1686         }
1687 }
1688
1689 static bool target_handle_task_attr(struct se_cmd *cmd)
1690 {
1691         struct se_device *dev = cmd->se_dev;
1692
1693         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1694                 return false;
1695
1696         /*
1697          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1698          * to allow the passed struct se_cmd list of tasks to the front of the list.
1699          */
1700         switch (cmd->sam_task_attr) {
1701         case MSG_HEAD_TAG:
1702                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1703                          "se_ordered_id: %u\n",
1704                          cmd->t_task_cdb[0], cmd->se_ordered_id);
1705                 return false;
1706         case MSG_ORDERED_TAG:
1707                 atomic_inc(&dev->dev_ordered_sync);
1708                 smp_mb__after_atomic_inc();
1709
1710                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1711                          " se_ordered_id: %u\n",
1712                          cmd->t_task_cdb[0], cmd->se_ordered_id);
1713
1714                 /*
1715                  * Execute an ORDERED command if no other older commands
1716                  * exist that need to be completed first.
1717                  */
1718                 if (!atomic_read(&dev->simple_cmds))
1719                         return false;
1720                 break;
1721         default:
1722                 /*
1723                  * For SIMPLE and UNTAGGED Task Attribute commands
1724                  */
1725                 atomic_inc(&dev->simple_cmds);
1726                 smp_mb__after_atomic_inc();
1727                 break;
1728         }
1729
1730         if (atomic_read(&dev->dev_ordered_sync) == 0)
1731                 return false;
1732
1733         spin_lock(&dev->delayed_cmd_lock);
1734         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1735         spin_unlock(&dev->delayed_cmd_lock);
1736
1737         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1738                 " delayed CMD list, se_ordered_id: %u\n",
1739                 cmd->t_task_cdb[0], cmd->sam_task_attr,
1740                 cmd->se_ordered_id);
1741         return true;
1742 }
1743
1744 void target_execute_cmd(struct se_cmd *cmd)
1745 {
1746         /*
1747          * If the received CDB has aleady been aborted stop processing it here.
1748          */
1749         if (transport_check_aborted_status(cmd, 1))
1750                 return;
1751
1752         /*
1753          * Determine if frontend context caller is requesting the stopping of
1754          * this command for frontend exceptions.
1755          */
1756         spin_lock_irq(&cmd->t_state_lock);
1757         if (cmd->transport_state & CMD_T_STOP) {
1758                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1759                         __func__, __LINE__,
1760                         cmd->se_tfo->get_task_tag(cmd));
1761
1762                 spin_unlock_irq(&cmd->t_state_lock);
1763                 complete(&cmd->t_transport_stop_comp);
1764                 return;
1765         }
1766
1767         cmd->t_state = TRANSPORT_PROCESSING;
1768         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1769         spin_unlock_irq(&cmd->t_state_lock);
1770         /*
1771          * Perform WRITE_INSERT of PI using software emulation when backend
1772          * device has PI enabled, if the transport has not already generated
1773          * PI using hardware WRITE_INSERT offload.
1774          */
1775         if (cmd->prot_op == TARGET_PROT_DOUT_INSERT) {
1776                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1777                         sbc_dif_generate(cmd);
1778         }
1779
1780         if (target_handle_task_attr(cmd)) {
1781                 spin_lock_irq(&cmd->t_state_lock);
1782                 cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT;
1783                 spin_unlock_irq(&cmd->t_state_lock);
1784                 return;
1785         }
1786
1787         __target_execute_cmd(cmd);
1788 }
1789 EXPORT_SYMBOL(target_execute_cmd);
1790
1791 /*
1792  * Process all commands up to the last received ORDERED task attribute which
1793  * requires another blocking boundary
1794  */
1795 static void target_restart_delayed_cmds(struct se_device *dev)
1796 {
1797         for (;;) {
1798                 struct se_cmd *cmd;
1799
1800                 spin_lock(&dev->delayed_cmd_lock);
1801                 if (list_empty(&dev->delayed_cmd_list)) {
1802                         spin_unlock(&dev->delayed_cmd_lock);
1803                         break;
1804                 }
1805
1806                 cmd = list_entry(dev->delayed_cmd_list.next,
1807                                  struct se_cmd, se_delayed_node);
1808                 list_del(&cmd->se_delayed_node);
1809                 spin_unlock(&dev->delayed_cmd_lock);
1810
1811                 __target_execute_cmd(cmd);
1812
1813                 if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1814                         break;
1815         }
1816 }
1817
1818 /*
1819  * Called from I/O completion to determine which dormant/delayed
1820  * and ordered cmds need to have their tasks added to the execution queue.
1821  */
1822 static void transport_complete_task_attr(struct se_cmd *cmd)
1823 {
1824         struct se_device *dev = cmd->se_dev;
1825
1826         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1827                 return;
1828
1829         if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1830                 atomic_dec(&dev->simple_cmds);
1831                 smp_mb__after_atomic_dec();
1832                 dev->dev_cur_ordered_id++;
1833                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1834                         " SIMPLE: %u\n", dev->dev_cur_ordered_id,
1835                         cmd->se_ordered_id);
1836         } else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1837                 dev->dev_cur_ordered_id++;
1838                 pr_debug("Incremented dev_cur_ordered_id: %u for"
1839                         " HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1840                         cmd->se_ordered_id);
1841         } else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1842                 atomic_dec(&dev->dev_ordered_sync);
1843                 smp_mb__after_atomic_dec();
1844
1845                 dev->dev_cur_ordered_id++;
1846                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1847                         " %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1848         }
1849
1850         target_restart_delayed_cmds(dev);
1851 }
1852
1853 static void transport_complete_qf(struct se_cmd *cmd)
1854 {
1855         int ret = 0;
1856
1857         transport_complete_task_attr(cmd);
1858
1859         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1860                 trace_target_cmd_complete(cmd);
1861                 ret = cmd->se_tfo->queue_status(cmd);
1862                 if (ret)
1863                         goto out;
1864         }
1865
1866         switch (cmd->data_direction) {
1867         case DMA_FROM_DEVICE:
1868                 trace_target_cmd_complete(cmd);
1869                 ret = cmd->se_tfo->queue_data_in(cmd);
1870                 break;
1871         case DMA_TO_DEVICE:
1872                 if (cmd->se_cmd_flags & SCF_BIDI) {
1873                         ret = cmd->se_tfo->queue_data_in(cmd);
1874                         if (ret < 0)
1875                                 break;
1876                 }
1877                 /* Fall through for DMA_TO_DEVICE */
1878         case DMA_NONE:
1879                 trace_target_cmd_complete(cmd);
1880                 ret = cmd->se_tfo->queue_status(cmd);
1881                 break;
1882         default:
1883                 break;
1884         }
1885
1886 out:
1887         if (ret < 0) {
1888                 transport_handle_queue_full(cmd, cmd->se_dev);
1889                 return;
1890         }
1891         transport_lun_remove_cmd(cmd);
1892         transport_cmd_check_stop_to_fabric(cmd);
1893 }
1894
1895 static void transport_handle_queue_full(
1896         struct se_cmd *cmd,
1897         struct se_device *dev)
1898 {
1899         spin_lock_irq(&dev->qf_cmd_lock);
1900         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1901         atomic_inc(&dev->dev_qf_count);
1902         smp_mb__after_atomic_inc();
1903         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1904
1905         schedule_work(&cmd->se_dev->qf_work_queue);
1906 }
1907
1908 static bool target_check_read_strip(struct se_cmd *cmd)
1909 {
1910         sense_reason_t rc;
1911
1912         if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
1913                 rc = sbc_dif_read_strip(cmd);
1914                 if (rc) {
1915                         cmd->pi_err = rc;
1916                         return true;
1917                 }
1918         }
1919
1920         return false;
1921 }
1922
1923 static void target_complete_ok_work(struct work_struct *work)
1924 {
1925         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1926         int ret;
1927
1928         /*
1929          * Check if we need to move delayed/dormant tasks from cmds on the
1930          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1931          * Attribute.
1932          */
1933         transport_complete_task_attr(cmd);
1934
1935         /*
1936          * Check to schedule QUEUE_FULL work, or execute an existing
1937          * cmd->transport_qf_callback()
1938          */
1939         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1940                 schedule_work(&cmd->se_dev->qf_work_queue);
1941
1942         /*
1943          * Check if we need to send a sense buffer from
1944          * the struct se_cmd in question.
1945          */
1946         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1947                 WARN_ON(!cmd->scsi_status);
1948                 ret = transport_send_check_condition_and_sense(
1949                                         cmd, 0, 1);
1950                 if (ret == -EAGAIN || ret == -ENOMEM)
1951                         goto queue_full;
1952
1953                 transport_lun_remove_cmd(cmd);
1954                 transport_cmd_check_stop_to_fabric(cmd);
1955                 return;
1956         }
1957         /*
1958          * Check for a callback, used by amongst other things
1959          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
1960          */
1961         if (cmd->transport_complete_callback) {
1962                 sense_reason_t rc;
1963
1964                 rc = cmd->transport_complete_callback(cmd);
1965                 if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
1966                         return;
1967                 } else if (rc) {
1968                         ret = transport_send_check_condition_and_sense(cmd,
1969                                                 rc, 0);
1970                         if (ret == -EAGAIN || ret == -ENOMEM)
1971                                 goto queue_full;
1972
1973                         transport_lun_remove_cmd(cmd);
1974                         transport_cmd_check_stop_to_fabric(cmd);
1975                         return;
1976                 }
1977         }
1978
1979         switch (cmd->data_direction) {
1980         case DMA_FROM_DEVICE:
1981                 spin_lock(&cmd->se_lun->lun_sep_lock);
1982                 if (cmd->se_lun->lun_sep) {
1983                         cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1984                                         cmd->data_length;
1985                 }
1986                 spin_unlock(&cmd->se_lun->lun_sep_lock);
1987                 /*
1988                  * Perform READ_STRIP of PI using software emulation when
1989                  * backend had PI enabled, if the transport will not be
1990                  * performing hardware READ_STRIP offload.
1991                  */
1992                 if (cmd->prot_op == TARGET_PROT_DIN_STRIP &&
1993                     target_check_read_strip(cmd)) {
1994                         ret = transport_send_check_condition_and_sense(cmd,
1995                                                 cmd->pi_err, 0);
1996                         if (ret == -EAGAIN || ret == -ENOMEM)
1997                                 goto queue_full;
1998
1999                         transport_lun_remove_cmd(cmd);
2000                         transport_cmd_check_stop_to_fabric(cmd);
2001                         return;
2002                 }
2003
2004                 trace_target_cmd_complete(cmd);
2005                 ret = cmd->se_tfo->queue_data_in(cmd);
2006                 if (ret == -EAGAIN || ret == -ENOMEM)
2007                         goto queue_full;
2008                 break;
2009         case DMA_TO_DEVICE:
2010                 spin_lock(&cmd->se_lun->lun_sep_lock);
2011                 if (cmd->se_lun->lun_sep) {
2012                         cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2013                                 cmd->data_length;
2014                 }
2015                 spin_unlock(&cmd->se_lun->lun_sep_lock);
2016                 /*
2017                  * Check if we need to send READ payload for BIDI-COMMAND
2018                  */
2019                 if (cmd->se_cmd_flags & SCF_BIDI) {
2020                         spin_lock(&cmd->se_lun->lun_sep_lock);
2021                         if (cmd->se_lun->lun_sep) {
2022                                 cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2023                                         cmd->data_length;
2024                         }
2025                         spin_unlock(&cmd->se_lun->lun_sep_lock);
2026                         ret = cmd->se_tfo->queue_data_in(cmd);
2027                         if (ret == -EAGAIN || ret == -ENOMEM)
2028                                 goto queue_full;
2029                         break;
2030                 }
2031                 /* Fall through for DMA_TO_DEVICE */
2032         case DMA_NONE:
2033                 trace_target_cmd_complete(cmd);
2034                 ret = cmd->se_tfo->queue_status(cmd);
2035                 if (ret == -EAGAIN || ret == -ENOMEM)
2036                         goto queue_full;
2037                 break;
2038         default:
2039                 break;
2040         }
2041
2042         transport_lun_remove_cmd(cmd);
2043         transport_cmd_check_stop_to_fabric(cmd);
2044         return;
2045
2046 queue_full:
2047         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2048                 " data_direction: %d\n", cmd, cmd->data_direction);
2049         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2050         transport_handle_queue_full(cmd, cmd->se_dev);
2051 }
2052
2053 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2054 {
2055         struct scatterlist *sg;
2056         int count;
2057
2058         for_each_sg(sgl, sg, nents, count)
2059                 __free_page(sg_page(sg));
2060
2061         kfree(sgl);
2062 }
2063
2064 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2065 {
2066         /*
2067          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2068          * emulation, and free + reset pointers if necessary..
2069          */
2070         if (!cmd->t_data_sg_orig)
2071                 return;
2072
2073         kfree(cmd->t_data_sg);
2074         cmd->t_data_sg = cmd->t_data_sg_orig;
2075         cmd->t_data_sg_orig = NULL;
2076         cmd->t_data_nents = cmd->t_data_nents_orig;
2077         cmd->t_data_nents_orig = 0;
2078 }
2079
2080 static inline void transport_free_pages(struct se_cmd *cmd)
2081 {
2082         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2083                 transport_reset_sgl_orig(cmd);
2084                 return;
2085         }
2086         transport_reset_sgl_orig(cmd);
2087
2088         transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2089         cmd->t_data_sg = NULL;
2090         cmd->t_data_nents = 0;
2091
2092         transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2093         cmd->t_bidi_data_sg = NULL;
2094         cmd->t_bidi_data_nents = 0;
2095
2096         transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2097         cmd->t_prot_sg = NULL;
2098         cmd->t_prot_nents = 0;
2099 }
2100
2101 /**
2102  * transport_release_cmd - free a command
2103  * @cmd:       command to free
2104  *
2105  * This routine unconditionally frees a command, and reference counting
2106  * or list removal must be done in the caller.
2107  */
2108 static int transport_release_cmd(struct se_cmd *cmd)
2109 {
2110         BUG_ON(!cmd->se_tfo);
2111
2112         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2113                 core_tmr_release_req(cmd->se_tmr_req);
2114         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2115                 kfree(cmd->t_task_cdb);
2116         /*
2117          * If this cmd has been setup with target_get_sess_cmd(), drop
2118          * the kref and call ->release_cmd() in kref callback.
2119          */
2120         return target_put_sess_cmd(cmd->se_sess, cmd);
2121 }
2122
2123 /**
2124  * transport_put_cmd - release a reference to a command
2125  * @cmd:       command to release
2126  *
2127  * This routine releases our reference to the command and frees it if possible.
2128  */
2129 static int transport_put_cmd(struct se_cmd *cmd)
2130 {
2131         transport_free_pages(cmd);
2132         return transport_release_cmd(cmd);
2133 }
2134
2135 void *transport_kmap_data_sg(struct se_cmd *cmd)
2136 {
2137         struct scatterlist *sg = cmd->t_data_sg;
2138         struct page **pages;
2139         int i;
2140
2141         /*
2142          * We need to take into account a possible offset here for fabrics like
2143          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2144          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2145          */
2146         if (!cmd->t_data_nents)
2147                 return NULL;
2148
2149         BUG_ON(!sg);
2150         if (cmd->t_data_nents == 1)
2151                 return kmap(sg_page(sg)) + sg->offset;
2152
2153         /* >1 page. use vmap */
2154         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2155         if (!pages)
2156                 return NULL;
2157
2158         /* convert sg[] to pages[] */
2159         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2160                 pages[i] = sg_page(sg);
2161         }
2162
2163         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2164         kfree(pages);
2165         if (!cmd->t_data_vmap)
2166                 return NULL;
2167
2168         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2169 }
2170 EXPORT_SYMBOL(transport_kmap_data_sg);
2171
2172 void transport_kunmap_data_sg(struct se_cmd *cmd)
2173 {
2174         if (!cmd->t_data_nents) {
2175                 return;
2176         } else if (cmd->t_data_nents == 1) {
2177                 kunmap(sg_page(cmd->t_data_sg));
2178                 return;
2179         }
2180
2181         vunmap(cmd->t_data_vmap);
2182         cmd->t_data_vmap = NULL;
2183 }
2184 EXPORT_SYMBOL(transport_kunmap_data_sg);
2185
2186 int
2187 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2188                  bool zero_page)
2189 {
2190         struct scatterlist *sg;
2191         struct page *page;
2192         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2193         unsigned int nent;
2194         int i = 0;
2195
2196         nent = DIV_ROUND_UP(length, PAGE_SIZE);
2197         sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2198         if (!sg)
2199                 return -ENOMEM;
2200
2201         sg_init_table(sg, nent);
2202
2203         while (length) {
2204                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2205                 page = alloc_page(GFP_KERNEL | zero_flag);
2206                 if (!page)
2207                         goto out;
2208
2209                 sg_set_page(&sg[i], page, page_len, 0);
2210                 length -= page_len;
2211                 i++;
2212         }
2213         *sgl = sg;
2214         *nents = nent;
2215         return 0;
2216
2217 out:
2218         while (i > 0) {
2219                 i--;
2220                 __free_page(sg_page(&sg[i]));
2221         }
2222         kfree(sg);
2223         return -ENOMEM;
2224 }
2225
2226 /*
2227  * Allocate any required resources to execute the command.  For writes we
2228  * might not have the payload yet, so notify the fabric via a call to
2229  * ->write_pending instead. Otherwise place it on the execution queue.
2230  */
2231 sense_reason_t
2232 transport_generic_new_cmd(struct se_cmd *cmd)
2233 {
2234         int ret = 0;
2235
2236         /*
2237          * Determine is the TCM fabric module has already allocated physical
2238          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2239          * beforehand.
2240          */
2241         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2242             cmd->data_length) {
2243                 bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2244
2245                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2246                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2247                         u32 bidi_length;
2248
2249                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2250                                 bidi_length = cmd->t_task_nolb *
2251                                               cmd->se_dev->dev_attrib.block_size;
2252                         else
2253                                 bidi_length = cmd->data_length;
2254
2255                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2256                                                &cmd->t_bidi_data_nents,
2257                                                bidi_length, zero_flag);
2258                         if (ret < 0)
2259                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2260                 }
2261
2262                 if (cmd->prot_op != TARGET_PROT_NORMAL) {
2263                         ret = target_alloc_sgl(&cmd->t_prot_sg,
2264                                                &cmd->t_prot_nents,
2265                                                cmd->prot_length, true);
2266                         if (ret < 0)
2267                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2268                 }
2269
2270                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2271                                        cmd->data_length, zero_flag);
2272                 if (ret < 0)
2273                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2274         }
2275         /*
2276          * If this command is not a write we can execute it right here,
2277          * for write buffers we need to notify the fabric driver first
2278          * and let it call back once the write buffers are ready.
2279          */
2280         target_add_to_state_list(cmd);
2281         if (cmd->data_direction != DMA_TO_DEVICE) {
2282                 target_execute_cmd(cmd);
2283                 return 0;
2284         }
2285         transport_cmd_check_stop(cmd, false, true);
2286
2287         ret = cmd->se_tfo->write_pending(cmd);
2288         if (ret == -EAGAIN || ret == -ENOMEM)
2289                 goto queue_full;
2290
2291         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2292         WARN_ON(ret);
2293
2294         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2295
2296 queue_full:
2297         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2298         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2299         transport_handle_queue_full(cmd, cmd->se_dev);
2300         return 0;
2301 }
2302 EXPORT_SYMBOL(transport_generic_new_cmd);
2303
2304 static void transport_write_pending_qf(struct se_cmd *cmd)
2305 {
2306         int ret;
2307
2308         ret = cmd->se_tfo->write_pending(cmd);
2309         if (ret == -EAGAIN || ret == -ENOMEM) {
2310                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2311                          cmd);
2312                 transport_handle_queue_full(cmd, cmd->se_dev);
2313         }
2314 }
2315
2316 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2317 {
2318         unsigned long flags;
2319         int ret = 0;
2320
2321         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2322                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2323                          transport_wait_for_tasks(cmd);
2324
2325                 ret = transport_release_cmd(cmd);
2326         } else {
2327                 if (wait_for_tasks)
2328                         transport_wait_for_tasks(cmd);
2329                 /*
2330                  * Handle WRITE failure case where transport_generic_new_cmd()
2331                  * has already added se_cmd to state_list, but fabric has
2332                  * failed command before I/O submission.
2333                  */
2334                 if (cmd->state_active) {
2335                         spin_lock_irqsave(&cmd->t_state_lock, flags);
2336                         target_remove_from_state_list(cmd);
2337                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2338                 }
2339
2340                 if (cmd->se_lun)
2341                         transport_lun_remove_cmd(cmd);
2342
2343                 ret = transport_put_cmd(cmd);
2344         }
2345         return ret;
2346 }
2347 EXPORT_SYMBOL(transport_generic_free_cmd);
2348
2349 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2350  * @se_sess:    session to reference
2351  * @se_cmd:     command descriptor to add
2352  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2353  */
2354 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2355                                bool ack_kref)
2356 {
2357         unsigned long flags;
2358         int ret = 0;
2359
2360         kref_init(&se_cmd->cmd_kref);
2361         /*
2362          * Add a second kref if the fabric caller is expecting to handle
2363          * fabric acknowledgement that requires two target_put_sess_cmd()
2364          * invocations before se_cmd descriptor release.
2365          */
2366         if (ack_kref == true) {
2367                 kref_get(&se_cmd->cmd_kref);
2368                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2369         }
2370
2371         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2372         if (se_sess->sess_tearing_down) {
2373                 ret = -ESHUTDOWN;
2374                 goto out;
2375         }
2376         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2377 out:
2378         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2379         return ret;
2380 }
2381 EXPORT_SYMBOL(target_get_sess_cmd);
2382
2383 static void target_release_cmd_kref(struct kref *kref)
2384 {
2385         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2386         struct se_session *se_sess = se_cmd->se_sess;
2387
2388         if (list_empty(&se_cmd->se_cmd_list)) {
2389                 spin_unlock(&se_sess->sess_cmd_lock);
2390                 se_cmd->se_tfo->release_cmd(se_cmd);
2391                 return;
2392         }
2393         if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2394                 spin_unlock(&se_sess->sess_cmd_lock);
2395                 complete(&se_cmd->cmd_wait_comp);
2396                 return;
2397         }
2398         list_del(&se_cmd->se_cmd_list);
2399         spin_unlock(&se_sess->sess_cmd_lock);
2400
2401         se_cmd->se_tfo->release_cmd(se_cmd);
2402 }
2403
2404 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2405  * @se_sess:    session to reference
2406  * @se_cmd:     command descriptor to drop
2407  */
2408 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2409 {
2410         return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2411                         &se_sess->sess_cmd_lock);
2412 }
2413 EXPORT_SYMBOL(target_put_sess_cmd);
2414
2415 /* target_sess_cmd_list_set_waiting - Flag all commands in
2416  *         sess_cmd_list to complete cmd_wait_comp.  Set
2417  *         sess_tearing_down so no more commands are queued.
2418  * @se_sess:    session to flag
2419  */
2420 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2421 {
2422         struct se_cmd *se_cmd;
2423         unsigned long flags;
2424
2425         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2426         if (se_sess->sess_tearing_down) {
2427                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2428                 return;
2429         }
2430         se_sess->sess_tearing_down = 1;
2431         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2432
2433         list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2434                 se_cmd->cmd_wait_set = 1;
2435
2436         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2437 }
2438 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2439
2440 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2441  * @se_sess:    session to wait for active I/O
2442  */
2443 void target_wait_for_sess_cmds(struct se_session *se_sess)
2444 {
2445         struct se_cmd *se_cmd, *tmp_cmd;
2446         unsigned long flags;
2447
2448         list_for_each_entry_safe(se_cmd, tmp_cmd,
2449                                 &se_sess->sess_wait_list, se_cmd_list) {
2450                 list_del(&se_cmd->se_cmd_list);
2451
2452                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2453                         " %d\n", se_cmd, se_cmd->t_state,
2454                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2455
2456                 wait_for_completion(&se_cmd->cmd_wait_comp);
2457                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2458                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2459                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2460
2461                 se_cmd->se_tfo->release_cmd(se_cmd);
2462         }
2463
2464         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2465         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2466         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2467
2468 }
2469 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2470
2471 static int transport_clear_lun_ref_thread(void *p)
2472 {
2473         struct se_lun *lun = p;
2474
2475         percpu_ref_kill(&lun->lun_ref);
2476
2477         wait_for_completion(&lun->lun_ref_comp);
2478         complete(&lun->lun_shutdown_comp);
2479
2480         return 0;
2481 }
2482
2483 int transport_clear_lun_ref(struct se_lun *lun)
2484 {
2485         struct task_struct *kt;
2486
2487         kt = kthread_run(transport_clear_lun_ref_thread, lun,
2488                         "tcm_cl_%u", lun->unpacked_lun);
2489         if (IS_ERR(kt)) {
2490                 pr_err("Unable to start clear_lun thread\n");
2491                 return PTR_ERR(kt);
2492         }
2493         wait_for_completion(&lun->lun_shutdown_comp);
2494
2495         return 0;
2496 }
2497
2498 /**
2499  * transport_wait_for_tasks - wait for completion to occur
2500  * @cmd:        command to wait
2501  *
2502  * Called from frontend fabric context to wait for storage engine
2503  * to pause and/or release frontend generated struct se_cmd.
2504  */
2505 bool transport_wait_for_tasks(struct se_cmd *cmd)
2506 {
2507         unsigned long flags;
2508
2509         spin_lock_irqsave(&cmd->t_state_lock, flags);
2510         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2511             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2512                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2513                 return false;
2514         }
2515
2516         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2517             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2518                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2519                 return false;
2520         }
2521
2522         if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2523                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2524                 return false;
2525         }
2526
2527         cmd->transport_state |= CMD_T_STOP;
2528
2529         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2530                 " i_state: %d, t_state: %d, CMD_T_STOP\n",
2531                 cmd, cmd->se_tfo->get_task_tag(cmd),
2532                 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2533
2534         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2535
2536         wait_for_completion(&cmd->t_transport_stop_comp);
2537
2538         spin_lock_irqsave(&cmd->t_state_lock, flags);
2539         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2540
2541         pr_debug("wait_for_tasks: Stopped wait_for_completion("
2542                 "&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2543                 cmd->se_tfo->get_task_tag(cmd));
2544
2545         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2546
2547         return true;
2548 }
2549 EXPORT_SYMBOL(transport_wait_for_tasks);
2550
2551 static int transport_get_sense_codes(
2552         struct se_cmd *cmd,
2553         u8 *asc,
2554         u8 *ascq)
2555 {
2556         *asc = cmd->scsi_asc;
2557         *ascq = cmd->scsi_ascq;
2558
2559         return 0;
2560 }
2561
2562 static
2563 void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
2564 {
2565         /* Place failed LBA in sense data information descriptor 0. */
2566         buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
2567         buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
2568         buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
2569         buffer[SPC_VALIDITY_OFFSET] = 0x80;
2570
2571         /* Descriptor Information: failing sector */
2572         put_unaligned_be64(bad_sector, &buffer[12]);
2573 }
2574
2575 int
2576 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2577                 sense_reason_t reason, int from_transport)
2578 {
2579         unsigned char *buffer = cmd->sense_buffer;
2580         unsigned long flags;
2581         u8 asc = 0, ascq = 0;
2582
2583         spin_lock_irqsave(&cmd->t_state_lock, flags);
2584         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2585                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2586                 return 0;
2587         }
2588         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2589         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2590
2591         if (!reason && from_transport)
2592                 goto after_reason;
2593
2594         if (!from_transport)
2595                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2596
2597         /*
2598          * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2599          * SENSE KEY values from include/scsi/scsi.h
2600          */
2601         switch (reason) {
2602         case TCM_NO_SENSE:
2603                 /* CURRENT ERROR */
2604                 buffer[0] = 0x70;
2605                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2606                 /* Not Ready */
2607                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2608                 /* NO ADDITIONAL SENSE INFORMATION */
2609                 buffer[SPC_ASC_KEY_OFFSET] = 0;
2610                 buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2611                 break;
2612         case TCM_NON_EXISTENT_LUN:
2613                 /* CURRENT ERROR */
2614                 buffer[0] = 0x70;
2615                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2616                 /* ILLEGAL REQUEST */
2617                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2618                 /* LOGICAL UNIT NOT SUPPORTED */
2619                 buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2620                 break;
2621         case TCM_UNSUPPORTED_SCSI_OPCODE:
2622         case TCM_SECTOR_COUNT_TOO_MANY:
2623                 /* CURRENT ERROR */
2624                 buffer[0] = 0x70;
2625                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2626                 /* ILLEGAL REQUEST */
2627                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2628                 /* INVALID COMMAND OPERATION CODE */
2629                 buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2630                 break;
2631         case TCM_UNKNOWN_MODE_PAGE:
2632                 /* CURRENT ERROR */
2633                 buffer[0] = 0x70;
2634                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2635                 /* ILLEGAL REQUEST */
2636                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2637                 /* INVALID FIELD IN CDB */
2638                 buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2639                 break;
2640         case TCM_CHECK_CONDITION_ABORT_CMD:
2641                 /* CURRENT ERROR */
2642                 buffer[0] = 0x70;
2643                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2644                 /* ABORTED COMMAND */
2645                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2646                 /* BUS DEVICE RESET FUNCTION OCCURRED */
2647                 buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2648                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2649                 break;
2650         case TCM_INCORRECT_AMOUNT_OF_DATA:
2651                 /* CURRENT ERROR */
2652                 buffer[0] = 0x70;
2653                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2654                 /* ABORTED COMMAND */
2655                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2656                 /* WRITE ERROR */
2657                 buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2658                 /* NOT ENOUGH UNSOLICITED DATA */
2659                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2660                 break;
2661         case TCM_INVALID_CDB_FIELD:
2662                 /* CURRENT ERROR */
2663                 buffer[0] = 0x70;
2664                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2665                 /* ILLEGAL REQUEST */
2666                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2667                 /* INVALID FIELD IN CDB */
2668                 buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2669                 break;
2670         case TCM_INVALID_PARAMETER_LIST:
2671                 /* CURRENT ERROR */
2672                 buffer[0] = 0x70;
2673                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2674                 /* ILLEGAL REQUEST */
2675                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2676                 /* INVALID FIELD IN PARAMETER LIST */
2677                 buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2678                 break;
2679         case TCM_PARAMETER_LIST_LENGTH_ERROR:
2680                 /* CURRENT ERROR */
2681                 buffer[0] = 0x70;
2682                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2683                 /* ILLEGAL REQUEST */
2684                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2685                 /* PARAMETER LIST LENGTH ERROR */
2686                 buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2687                 break;
2688         case TCM_UNEXPECTED_UNSOLICITED_DATA:
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                 /* WRITE ERROR */
2695                 buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2696                 /* UNEXPECTED_UNSOLICITED_DATA */
2697                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2698                 break;
2699         case TCM_SERVICE_CRC_ERROR:
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                 /* PROTOCOL SERVICE CRC ERROR */
2706                 buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2707                 /* N/A */
2708                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2709                 break;
2710         case TCM_SNACK_REJECTED:
2711                 /* CURRENT ERROR */
2712                 buffer[0] = 0x70;
2713                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2714                 /* ABORTED COMMAND */
2715                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2716                 /* READ ERROR */
2717                 buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2718                 /* FAILED RETRANSMISSION REQUEST */
2719                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2720                 break;
2721         case TCM_WRITE_PROTECTED:
2722                 /* CURRENT ERROR */
2723                 buffer[0] = 0x70;
2724                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2725                 /* DATA PROTECT */
2726                 buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2727                 /* WRITE PROTECTED */
2728                 buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2729                 break;
2730         case TCM_ADDRESS_OUT_OF_RANGE:
2731                 /* CURRENT ERROR */
2732                 buffer[0] = 0x70;
2733                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2734                 /* ILLEGAL REQUEST */
2735                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2736                 /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2737                 buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2738                 break;
2739         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2740                 /* CURRENT ERROR */
2741                 buffer[0] = 0x70;
2742                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2743                 /* UNIT ATTENTION */
2744                 buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2745                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2746                 buffer[SPC_ASC_KEY_OFFSET] = asc;
2747                 buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2748                 break;
2749         case TCM_CHECK_CONDITION_NOT_READY:
2750                 /* CURRENT ERROR */
2751                 buffer[0] = 0x70;
2752                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2753                 /* Not Ready */
2754                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2755                 transport_get_sense_codes(cmd, &asc, &ascq);
2756                 buffer[SPC_ASC_KEY_OFFSET] = asc;
2757                 buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2758                 break;
2759         case TCM_MISCOMPARE_VERIFY:
2760                 /* CURRENT ERROR */
2761                 buffer[0] = 0x70;
2762                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2763                 buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2764                 /* MISCOMPARE DURING VERIFY OPERATION */
2765                 buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2766                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2767                 break;
2768         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2769                 /* CURRENT ERROR */
2770                 buffer[0] = 0x70;
2771                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2772                 /* ILLEGAL REQUEST */
2773                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2774                 /* LOGICAL BLOCK GUARD CHECK FAILED */
2775                 buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2776                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
2777                 transport_err_sector_info(buffer, cmd->bad_sector);
2778                 break;
2779         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2780                 /* CURRENT ERROR */
2781                 buffer[0] = 0x70;
2782                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2783                 /* ILLEGAL REQUEST */
2784                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2785                 /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2786                 buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2787                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
2788                 transport_err_sector_info(buffer, cmd->bad_sector);
2789                 break;
2790         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2791                 /* CURRENT ERROR */
2792                 buffer[0] = 0x70;
2793                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2794                 /* ILLEGAL REQUEST */
2795                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2796                 /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2797                 buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2798                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2799                 transport_err_sector_info(buffer, cmd->bad_sector);
2800                 break;
2801         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2802         default:
2803                 /* CURRENT ERROR */
2804                 buffer[0] = 0x70;
2805                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2806                 /*
2807                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2808                  * Solaris initiators.  Returning NOT READY instead means the
2809                  * operations will be retried a finite number of times and we
2810                  * can survive intermittent errors.
2811                  */
2812                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2813                 /* LOGICAL UNIT COMMUNICATION FAILURE */
2814                 buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2815                 break;
2816         }
2817         /*
2818          * This code uses linux/include/scsi/scsi.h SAM status codes!
2819          */
2820         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2821         /*
2822          * Automatically padded, this value is encoded in the fabric's
2823          * data_length response PDU containing the SCSI defined sense data.
2824          */
2825         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2826
2827 after_reason:
2828         trace_target_cmd_complete(cmd);
2829         return cmd->se_tfo->queue_status(cmd);
2830 }
2831 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2832
2833 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2834 {
2835         if (!(cmd->transport_state & CMD_T_ABORTED))
2836                 return 0;
2837
2838         /*
2839          * If cmd has been aborted but either no status is to be sent or it has
2840          * already been sent, just return
2841          */
2842         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
2843                 return 1;
2844
2845         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2846                  cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2847
2848         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2849         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2850         trace_target_cmd_complete(cmd);
2851         cmd->se_tfo->queue_status(cmd);
2852
2853         return 1;
2854 }
2855 EXPORT_SYMBOL(transport_check_aborted_status);
2856
2857 void transport_send_task_abort(struct se_cmd *cmd)
2858 {
2859         unsigned long flags;
2860
2861         spin_lock_irqsave(&cmd->t_state_lock, flags);
2862         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
2863                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2864                 return;
2865         }
2866         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2867
2868         /*
2869          * If there are still expected incoming fabric WRITEs, we wait
2870          * until until they have completed before sending a TASK_ABORTED
2871          * response.  This response with TASK_ABORTED status will be
2872          * queued back to fabric module by transport_check_aborted_status().
2873          */
2874         if (cmd->data_direction == DMA_TO_DEVICE) {
2875                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2876                         cmd->transport_state |= CMD_T_ABORTED;
2877                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
2878                         smp_mb__after_atomic_inc();
2879                         return;
2880                 }
2881         }
2882         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2883
2884         transport_lun_remove_cmd(cmd);
2885
2886         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2887                 " ITT: 0x%08x\n", cmd->t_task_cdb[0],
2888                 cmd->se_tfo->get_task_tag(cmd));
2889
2890         trace_target_cmd_complete(cmd);
2891         cmd->se_tfo->queue_status(cmd);
2892 }
2893
2894 static void target_tmr_work(struct work_struct *work)
2895 {
2896         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2897         struct se_device *dev = cmd->se_dev;
2898         struct se_tmr_req *tmr = cmd->se_tmr_req;
2899         int ret;
2900
2901         switch (tmr->function) {
2902         case TMR_ABORT_TASK:
2903                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
2904                 break;
2905         case TMR_ABORT_TASK_SET:
2906         case TMR_CLEAR_ACA:
2907         case TMR_CLEAR_TASK_SET:
2908                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2909                 break;
2910         case TMR_LUN_RESET:
2911                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2912                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2913                                          TMR_FUNCTION_REJECTED;
2914                 break;
2915         case TMR_TARGET_WARM_RESET:
2916                 tmr->response = TMR_FUNCTION_REJECTED;
2917                 break;
2918         case TMR_TARGET_COLD_RESET:
2919                 tmr->response = TMR_FUNCTION_REJECTED;
2920                 break;
2921         default:
2922                 pr_err("Uknown TMR function: 0x%02x.\n",
2923                                 tmr->function);
2924                 tmr->response = TMR_FUNCTION_REJECTED;
2925                 break;
2926         }
2927
2928         cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2929         cmd->se_tfo->queue_tm_rsp(cmd);
2930
2931         transport_cmd_check_stop_to_fabric(cmd);
2932 }
2933
2934 int transport_generic_handle_tmr(
2935         struct se_cmd *cmd)
2936 {
2937         INIT_WORK(&cmd->work, target_tmr_work);
2938         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2939         return 0;
2940 }
2941 EXPORT_SYMBOL(transport_generic_handle_tmr);