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 <linux/vmalloc.h>
  38 #include <asm/unaligned.h>
  39 #include <net/sock.h>
  40 #include <net/tcp.h>
  41 #include <scsi/scsi_proto.h>
  42 #include <scsi/scsi_common.h>
  43
  44 #include <target/target_core_base.h>
  45 #include <target/target_core_backend.h>
  46 #include <target/target_core_fabric.h>
  47
  48 #include "target_core_internal.h"
  49 #include "target_core_alua.h"
  50 #include "target_core_pr.h"
  51 #include "target_core_ua.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/target.h>
  55
  56 static struct workqueue_struct *target_completion_wq;
  57 static struct kmem_cache *se_sess_cache;
  58 struct kmem_cache *se_ua_cache;
  59 struct kmem_cache *t10_pr_reg_cache;
  60 struct kmem_cache *t10_alua_lu_gp_cache;
  61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  63 struct kmem_cache *t10_alua_lba_map_cache;
  64 struct kmem_cache *t10_alua_lba_map_mem_cache;
  65
  66 static void transport_complete_task_attr(struct se_cmd *cmd);
  67 static void transport_handle_queue_full(struct se_cmd *cmd,
  68                 struct se_device *dev);
  69 static int transport_put_cmd(struct se_cmd *cmd);
  70 static void target_complete_ok_work(struct work_struct *work);
  71
  72 int init_se_kmem_caches(void)
  73 {
  74         se_sess_cache = kmem_cache_create("se_sess_cache",
  75                         sizeof(struct se_session), __alignof__(struct se_session),
  76                         0, NULL);
  77         if (!se_sess_cache) {
  78                 pr_err("kmem_cache_create() for struct se_session"
  79                                 " failed\n");
  80                 goto out;
  81         }
  82         se_ua_cache = kmem_cache_create("se_ua_cache",
  83                         sizeof(struct se_ua), __alignof__(struct se_ua),
  84                         0, NULL);
  85         if (!se_ua_cache) {
  86                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  87                 goto out_free_sess_cache;
  88         }
  89         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  90                         sizeof(struct t10_pr_registration),
  91                         __alignof__(struct t10_pr_registration), 0, NULL);
  92         if (!t10_pr_reg_cache) {
  93                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  94                                 " failed\n");
  95                 goto out_free_ua_cache;
  96         }
  97         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  98                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  99                         0, NULL);
 100         if (!t10_alua_lu_gp_cache) {
 101                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 102                                 " failed\n");
 103                 goto out_free_pr_reg_cache;
 104         }
 105         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 106                         sizeof(struct t10_alua_lu_gp_member),
 107                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 108         if (!t10_alua_lu_gp_mem_cache) {
 109                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 110                                 "cache failed\n");
 111                 goto out_free_lu_gp_cache;
 112         }
 113         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 114                         sizeof(struct t10_alua_tg_pt_gp),
 115                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 116         if (!t10_alua_tg_pt_gp_cache) {
 117                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 118                                 "cache failed\n");
 119                 goto out_free_lu_gp_mem_cache;
 120         }
 121         t10_alua_lba_map_cache = kmem_cache_create(
 122                         "t10_alua_lba_map_cache",
 123                         sizeof(struct t10_alua_lba_map),
 124                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 125         if (!t10_alua_lba_map_cache) {
 126                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 127                                 "cache failed\n");
 128                 goto out_free_tg_pt_gp_cache;
 129         }
 130         t10_alua_lba_map_mem_cache = kmem_cache_create(
 131                         "t10_alua_lba_map_mem_cache",
 132                         sizeof(struct t10_alua_lba_map_member),
 133                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 134         if (!t10_alua_lba_map_mem_cache) {
 135                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 136                                 "cache failed\n");
 137                 goto out_free_lba_map_cache;
 138         }
 139
 140         target_completion_wq = alloc_workqueue("target_completion",
 141                                                WQ_MEM_RECLAIM, 0);
 142         if (!target_completion_wq)
 143                 goto out_free_lba_map_mem_cache;
 144
 145         return 0;
 146
 147 out_free_lba_map_mem_cache:
 148         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 149 out_free_lba_map_cache:
 150         kmem_cache_destroy(t10_alua_lba_map_cache);
 151 out_free_tg_pt_gp_cache:
 152         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 153 out_free_lu_gp_mem_cache:
 154         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 155 out_free_lu_gp_cache:
 156         kmem_cache_destroy(t10_alua_lu_gp_cache);
 157 out_free_pr_reg_cache:
 158         kmem_cache_destroy(t10_pr_reg_cache);
 159 out_free_ua_cache:
 160         kmem_cache_destroy(se_ua_cache);
 161 out_free_sess_cache:
 162         kmem_cache_destroy(se_sess_cache);
 163 out:
 164         return -ENOMEM;
 165 }
 166
 167 void release_se_kmem_caches(void)
 168 {
 169         destroy_workqueue(target_completion_wq);
 170         kmem_cache_destroy(se_sess_cache);
 171         kmem_cache_destroy(se_ua_cache);
 172         kmem_cache_destroy(t10_pr_reg_cache);
 173         kmem_cache_destroy(t10_alua_lu_gp_cache);
 174         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 175         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 176         kmem_cache_destroy(t10_alua_lba_map_cache);
 177         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 178 }
 179
 180 /* This code ensures unique mib indexes are handed out. */
 181 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 182 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 183
 184 /*
 185  * Allocate a new row index for the entry type specified
 186  */
 187 u32 scsi_get_new_index(scsi_index_t type)
 188 {
 189         u32 new_index;
 190
 191         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 192
 193         spin_lock(&scsi_mib_index_lock);
 194         new_index = ++scsi_mib_index[type];
 195         spin_unlock(&scsi_mib_index_lock);
 196
 197         return new_index;
 198 }
 199
 200 void transport_subsystem_check_init(void)
 201 {
 202         int ret;
 203         static int sub_api_initialized;
 204
 205         if (sub_api_initialized)
 206                 return;
 207
 208         ret = request_module("target_core_iblock");
 209         if (ret != 0)
 210                 pr_err("Unable to load target_core_iblock\n");
 211
 212         ret = request_module("target_core_file");
 213         if (ret != 0)
 214                 pr_err("Unable to load target_core_file\n");
 215
 216         ret = request_module("target_core_pscsi");
 217         if (ret != 0)
 218                 pr_err("Unable to load target_core_pscsi\n");
 219
 220         ret = request_module("target_core_user");
 221         if (ret != 0)
 222                 pr_err("Unable to load target_core_user\n");
 223
 224         sub_api_initialized = 1;
 225 }
 226
 227 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
 228 {
 229         struct se_session *se_sess;
 230
 231         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 232         if (!se_sess) {
 233                 pr_err("Unable to allocate struct se_session from"
 234                                 " se_sess_cache\n");
 235                 return ERR_PTR(-ENOMEM);
 236         }
 237         INIT_LIST_HEAD(&se_sess->sess_list);
 238         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 239         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 240         INIT_LIST_HEAD(&se_sess->sess_wait_list);
 241         spin_lock_init(&se_sess->sess_cmd_lock);
 242         kref_init(&se_sess->sess_kref);
 243         se_sess->sup_prot_ops = sup_prot_ops;
 244
 245         return se_sess;
 246 }
 247 EXPORT_SYMBOL(transport_init_session);
 248
 249 int transport_alloc_session_tags(struct se_session *se_sess,
 250                                  unsigned int tag_num, unsigned int tag_size)
 251 {
 252         int rc;
 253
 254         se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
 255                                         GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
 256         if (!se_sess->sess_cmd_map) {
 257                 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
 258                 if (!se_sess->sess_cmd_map) {
 259                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 260                         return -ENOMEM;
 261                 }
 262         }
 263
 264         rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
 265         if (rc < 0) {
 266                 pr_err("Unable to init se_sess->sess_tag_pool,"
 267                         " tag_num: %u\n", tag_num);
 268                 kvfree(se_sess->sess_cmd_map);
 269                 se_sess->sess_cmd_map = NULL;
 270                 return -ENOMEM;
 271         }
 272
 273         return 0;
 274 }
 275 EXPORT_SYMBOL(transport_alloc_session_tags);
 276
 277 struct se_session *transport_init_session_tags(unsigned int tag_num,
 278                                                unsigned int tag_size,
 279                                                enum target_prot_op sup_prot_ops)
 280 {
 281         struct se_session *se_sess;
 282         int rc;
 283
 284         se_sess = transport_init_session(sup_prot_ops);
 285         if (IS_ERR(se_sess))
 286                 return se_sess;
 287
 288         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 289         if (rc < 0) {
 290                 transport_free_session(se_sess);
 291                 return ERR_PTR(-ENOMEM);
 292         }
 293
 294         return se_sess;
 295 }
 296 EXPORT_SYMBOL(transport_init_session_tags);
 297
 298 /*
 299  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 300  */
 301 void __transport_register_session(
 302         struct se_portal_group *se_tpg,
 303         struct se_node_acl *se_nacl,
 304         struct se_session *se_sess,
 305         void *fabric_sess_ptr)
 306 {
 307         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 308         unsigned char buf[PR_REG_ISID_LEN];
 309
 310         se_sess->se_tpg = se_tpg;
 311         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 312         /*
 313          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 314          *
 315          * Only set for struct se_session's that will actually be moving I/O.
 316          * eg: *NOT* discovery sessions.
 317          */
 318         if (se_nacl) {
 319                 /*
 320                  *
 321                  * Determine if fabric allows for T10-PI feature bits exposed to
 322                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 323                  *
 324                  * If so, then always save prot_type on a per se_node_acl node
 325                  * basis and re-instate the previous sess_prot_type to avoid
 326                  * disabling PI from below any previously initiator side
 327                  * registered LUNs.
 328                  */
 329                 if (se_nacl->saved_prot_type)
 330                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 331                 else if (tfo->tpg_check_prot_fabric_only)
 332                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 333                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 334                 /*
 335                  * If the fabric module supports an ISID based TransportID,
 336                  * save this value in binary from the fabric I_T Nexus now.
 337                  */
 338                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 339                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 340                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 341                                         &buf[0], PR_REG_ISID_LEN);
 342                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 343                 }
 344                 kref_get(&se_nacl->acl_kref);
 345
 346                 spin_lock_irq(&se_nacl->nacl_sess_lock);
 347                 /*
 348                  * The se_nacl->nacl_sess pointer will be set to the
 349                  * last active I_T Nexus for each struct se_node_acl.
 350                  */
 351                 se_nacl->nacl_sess = se_sess;
 352
 353                 list_add_tail(&se_sess->sess_acl_list,
 354                               &se_nacl->acl_sess_list);
 355                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
 356         }
 357         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 358
 359         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 360                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 361 }
 362 EXPORT_SYMBOL(__transport_register_session);
 363
 364 void transport_register_session(
 365         struct se_portal_group *se_tpg,
 366         struct se_node_acl *se_nacl,
 367         struct se_session *se_sess,
 368         void *fabric_sess_ptr)
 369 {
 370         unsigned long flags;
 371
 372         spin_lock_irqsave(&se_tpg->session_lock, flags);
 373         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 374         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 375 }
 376 EXPORT_SYMBOL(transport_register_session);
 377
 378 static void target_release_session(struct kref *kref)
 379 {
 380         struct se_session *se_sess = container_of(kref,
 381                         struct se_session, sess_kref);
 382         struct se_portal_group *se_tpg = se_sess->se_tpg;
 383
 384         se_tpg->se_tpg_tfo->close_session(se_sess);
 385 }
 386
 387 void target_get_session(struct se_session *se_sess)
 388 {
 389         kref_get(&se_sess->sess_kref);
 390 }
 391 EXPORT_SYMBOL(target_get_session);
 392
 393 void target_put_session(struct se_session *se_sess)
 394 {
 395         kref_put(&se_sess->sess_kref, target_release_session);
 396 }
 397 EXPORT_SYMBOL(target_put_session);
 398
 399 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 400 {
 401         struct se_session *se_sess;
 402         ssize_t len = 0;
 403
 404         spin_lock_bh(&se_tpg->session_lock);
 405         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 406                 if (!se_sess->se_node_acl)
 407                         continue;
 408                 if (!se_sess->se_node_acl->dynamic_node_acl)
 409                         continue;
 410                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 411                         break;
 412
 413                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 414                                 se_sess->se_node_acl->initiatorname);
 415                 len += 1; /* Include NULL terminator */
 416         }
 417         spin_unlock_bh(&se_tpg->session_lock);
 418
 419         return len;
 420 }
 421 EXPORT_SYMBOL(target_show_dynamic_sessions);
 422
 423 static void target_complete_nacl(struct kref *kref)
 424 {
 425         struct se_node_acl *nacl = container_of(kref,
 426                                 struct se_node_acl, acl_kref);
 427
 428         complete(&nacl->acl_free_comp);
 429 }
 430
 431 void target_put_nacl(struct se_node_acl *nacl)
 432 {
 433         kref_put(&nacl->acl_kref, target_complete_nacl);
 434 }
 435
 436 void transport_deregister_session_configfs(struct se_session *se_sess)
 437 {
 438         struct se_node_acl *se_nacl;
 439         unsigned long flags;
 440         /*
 441          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 442          */
 443         se_nacl = se_sess->se_node_acl;
 444         if (se_nacl) {
 445                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 446                 if (se_nacl->acl_stop == 0)
 447                         list_del(&se_sess->sess_acl_list);
 448                 /*
 449                  * If the session list is empty, then clear the pointer.
 450                  * Otherwise, set the struct se_session pointer from the tail
 451                  * element of the per struct se_node_acl active session list.
 452                  */
 453                 if (list_empty(&se_nacl->acl_sess_list))
 454                         se_nacl->nacl_sess = NULL;
 455                 else {
 456                         se_nacl->nacl_sess = container_of(
 457                                         se_nacl->acl_sess_list.prev,
 458                                         struct se_session, sess_acl_list);
 459                 }
 460                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 461         }
 462 }
 463 EXPORT_SYMBOL(transport_deregister_session_configfs);
 464
 465 void transport_free_session(struct se_session *se_sess)
 466 {
 467         if (se_sess->sess_cmd_map) {
 468                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 469                 kvfree(se_sess->sess_cmd_map);
 470         }
 471         kmem_cache_free(se_sess_cache, se_sess);
 472 }
 473 EXPORT_SYMBOL(transport_free_session);
 474
 475 void transport_deregister_session(struct se_session *se_sess)
 476 {
 477         struct se_portal_group *se_tpg = se_sess->se_tpg;
 478         const struct target_core_fabric_ops *se_tfo;
 479         struct se_node_acl *se_nacl;
 480         unsigned long flags;
 481         bool comp_nacl = true, drop_nacl = false;
 482
 483         if (!se_tpg) {
 484                 transport_free_session(se_sess);
 485                 return;
 486         }
 487         se_tfo = se_tpg->se_tpg_tfo;
 488
 489         spin_lock_irqsave(&se_tpg->session_lock, flags);
 490         list_del(&se_sess->sess_list);
 491         se_sess->se_tpg = NULL;
 492         se_sess->fabric_sess_ptr = NULL;
 493         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 494
 495         /*
 496          * Determine if we need to do extra work for this initiator node's
 497          * struct se_node_acl if it had been previously dynamically generated.
 498          */
 499         se_nacl = se_sess->se_node_acl;
 500
 501         mutex_lock(&se_tpg->acl_node_mutex);
 502         if (se_nacl && se_nacl->dynamic_node_acl) {
 503                 if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 504                         list_del(&se_nacl->acl_list);
 505                         drop_nacl = true;
 506                 }
 507         }
 508         mutex_unlock(&se_tpg->acl_node_mutex);
 509
 510         if (drop_nacl) {
 511                 core_tpg_wait_for_nacl_pr_ref(se_nacl);
 512                 core_free_device_list_for_node(se_nacl, se_tpg);
 513                 kfree(se_nacl);
 514                 comp_nacl = false;
 515         }
 516         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 517                 se_tpg->se_tpg_tfo->get_fabric_name());
 518         /*
 519          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 520          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 521          * removal context.
 522          */
 523         if (se_nacl && comp_nacl)
 524                 target_put_nacl(se_nacl);
 525
 526         transport_free_session(se_sess);
 527 }
 528 EXPORT_SYMBOL(transport_deregister_session);
 529
 530 /*
 531  * Called with cmd->t_state_lock held.
 532  */
 533 static void target_remove_from_state_list(struct se_cmd *cmd)
 534 {
 535         struct se_device *dev = cmd->se_dev;
 536         unsigned long flags;
 537
 538         if (!dev)
 539                 return;
 540
 541         if (cmd->transport_state & CMD_T_BUSY)
 542                 return;
 543
 544         spin_lock_irqsave(&dev->execute_task_lock, flags);
 545         if (cmd->state_active) {
 546                 list_del(&cmd->state_list);
 547                 cmd->state_active = false;
 548         }
 549         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 550 }
 551
 552 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 553                                     bool write_pending)
 554 {
 555         unsigned long flags;
 556
 557         spin_lock_irqsave(&cmd->t_state_lock, flags);
 558         if (write_pending)
 559                 cmd->t_state = TRANSPORT_WRITE_PENDING;
 560
 561         if (remove_from_lists) {
 562                 target_remove_from_state_list(cmd);
 563
 564                 /*
 565                  * Clear struct se_cmd->se_lun before the handoff to FE.
 566                  */
 567                 cmd->se_lun = NULL;
 568         }
 569
 570         /*
 571          * Determine if frontend context caller is requesting the stopping of
 572          * this command for frontend exceptions.
 573          */
 574         if (cmd->transport_state & CMD_T_STOP) {
 575                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 576                         __func__, __LINE__, cmd->tag);
 577
 578                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 579
 580                 complete_all(&cmd->t_transport_stop_comp);
 581                 return 1;
 582         }
 583
 584         cmd->transport_state &= ~CMD_T_ACTIVE;
 585         if (remove_from_lists) {
 586                 /*
 587                  * Some fabric modules like tcm_loop can release
 588                  * their internally allocated I/O reference now and
 589                  * struct se_cmd now.
 590                  *
 591                  * Fabric modules are expected to return '1' here if the
 592                  * se_cmd being passed is released at this point,
 593                  * or zero if not being released.
 594                  */
 595                 if (cmd->se_tfo->check_stop_free != NULL) {
 596                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 597                         return cmd->se_tfo->check_stop_free(cmd);
 598                 }
 599         }
 600
 601         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 602         return 0;
 603 }
 604
 605 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 606 {
 607         return transport_cmd_check_stop(cmd, true, false);
 608 }
 609
 610 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 611 {
 612         struct se_lun *lun = cmd->se_lun;
 613
 614         if (!lun)
 615                 return;
 616
 617         if (cmpxchg(&cmd->lun_ref_active, true, false))
 618                 percpu_ref_put(&lun->lun_ref);
 619 }
 620
 621 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 622 {
 623         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 624                 transport_lun_remove_cmd(cmd);
 625         /*
 626          * Allow the fabric driver to unmap any resources before
 627          * releasing the descriptor via TFO->release_cmd()
 628          */
 629         if (remove)
 630                 cmd->se_tfo->aborted_task(cmd);
 631
 632         if (transport_cmd_check_stop_to_fabric(cmd))
 633                 return;
 634         if (remove)
 635                 transport_put_cmd(cmd);
 636 }
 637
 638 static void target_complete_failure_work(struct work_struct *work)
 639 {
 640         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 641
 642         transport_generic_request_failure(cmd,
 643                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 644 }
 645
 646 /*
 647  * Used when asking transport to copy Sense Data from the underlying
 648  * Linux/SCSI struct scsi_cmnd
 649  */
 650 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 651 {
 652         struct se_device *dev = cmd->se_dev;
 653
 654         WARN_ON(!cmd->se_lun);
 655
 656         if (!dev)
 657                 return NULL;
 658
 659         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 660                 return NULL;
 661
 662         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 663
 664         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 665                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 666         return cmd->sense_buffer;
 667 }
 668
 669 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 670 {
 671         struct se_device *dev = cmd->se_dev;
 672         int success = scsi_status == GOOD;
 673         unsigned long flags;
 674
 675         cmd->scsi_status = scsi_status;
 676
 677
 678         spin_lock_irqsave(&cmd->t_state_lock, flags);
 679         cmd->transport_state &= ~CMD_T_BUSY;
 680
 681         if (dev && dev->transport->transport_complete) {
 682                 dev->transport->transport_complete(cmd,
 683                                 cmd->t_data_sg,
 684                                 transport_get_sense_buffer(cmd));
 685                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 686                         success = 1;
 687         }
 688
 689         /*
 690          * See if we are waiting to complete for an exception condition.
 691          */
 692         if (cmd->transport_state & CMD_T_REQUEST_STOP) {
 693                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 694                 complete(&cmd->task_stop_comp);
 695                 return;
 696         }
 697
 698         /*
 699          * Check for case where an explicit ABORT_TASK has been received
 700          * and transport_wait_for_tasks() will be waiting for completion..
 701          */
 702         if (cmd->transport_state & CMD_T_ABORTED &&
 703             cmd->transport_state & CMD_T_STOP) {
 704                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 705                 complete_all(&cmd->t_transport_stop_comp);
 706                 return;
 707         } else if (!success) {
 708                 INIT_WORK(&cmd->work, target_complete_failure_work);
 709         } else {
 710                 INIT_WORK(&cmd->work, target_complete_ok_work);
 711         }
 712
 713         cmd->t_state = TRANSPORT_COMPLETE;
 714         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 715         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 716
 717         if (cmd->cpuid == -1)
 718                 queue_work(target_completion_wq, &cmd->work);
 719         else
 720                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 721 }
 722 EXPORT_SYMBOL(target_complete_cmd);
 723
 724 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 725 {
 726         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 727                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 728                         cmd->residual_count += cmd->data_length - length;
 729                 } else {
 730                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 731                         cmd->residual_count = cmd->data_length - length;
 732                 }
 733
 734                 cmd->data_length = length;
 735         }
 736
 737         target_complete_cmd(cmd, scsi_status);
 738 }
 739 EXPORT_SYMBOL(target_complete_cmd_with_length);
 740
 741 static void target_add_to_state_list(struct se_cmd *cmd)
 742 {
 743         struct se_device *dev = cmd->se_dev;
 744         unsigned long flags;
 745
 746         spin_lock_irqsave(&dev->execute_task_lock, flags);
 747         if (!cmd->state_active) {
 748                 list_add_tail(&cmd->state_list, &dev->state_list);
 749                 cmd->state_active = true;
 750         }
 751         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 752 }
 753
 754 /*
 755  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 756  */
 757 static void transport_write_pending_qf(struct se_cmd *cmd);
 758 static void transport_complete_qf(struct se_cmd *cmd);
 759
 760 void target_qf_do_work(struct work_struct *work)
 761 {
 762         struct se_device *dev = container_of(work, struct se_device,
 763                                         qf_work_queue);
 764         LIST_HEAD(qf_cmd_list);
 765         struct se_cmd *cmd, *cmd_tmp;
 766
 767         spin_lock_irq(&dev->qf_cmd_lock);
 768         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 769         spin_unlock_irq(&dev->qf_cmd_lock);
 770
 771         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 772                 list_del(&cmd->se_qf_node);
 773                 atomic_dec_mb(&dev->dev_qf_count);
 774
 775                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 776                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 777                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 778                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 779                         : "UNKNOWN");
 780
 781                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 782                         transport_write_pending_qf(cmd);
 783                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 784                         transport_complete_qf(cmd);
 785         }
 786 }
 787
 788 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 789 {
 790         switch (cmd->data_direction) {
 791         case DMA_NONE:
 792                 return "NONE";
 793         case DMA_FROM_DEVICE:
 794                 return "READ";
 795         case DMA_TO_DEVICE:
 796                 return "WRITE";
 797         case DMA_BIDIRECTIONAL:
 798                 return "BIDI";
 799         default:
 800                 break;
 801         }
 802
 803         return "UNKNOWN";
 804 }
 805
 806 void transport_dump_dev_state(
 807         struct se_device *dev,
 808         char *b,
 809         int *bl)
 810 {
 811         *bl += sprintf(b + *bl, "Status: ");
 812         if (dev->export_count)
 813                 *bl += sprintf(b + *bl, "ACTIVATED");
 814         else
 815                 *bl += sprintf(b + *bl, "DEACTIVATED");
 816
 817         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 818         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 819                 dev->dev_attrib.block_size,
 820                 dev->dev_attrib.hw_max_sectors);
 821         *bl += sprintf(b + *bl, "        ");
 822 }
 823
 824 void transport_dump_vpd_proto_id(
 825         struct t10_vpd *vpd,
 826         unsigned char *p_buf,
 827         int p_buf_len)
 828 {
 829         unsigned char buf[VPD_TMP_BUF_SIZE];
 830         int len;
 831
 832         memset(buf, 0, VPD_TMP_BUF_SIZE);
 833         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 834
 835         switch (vpd->protocol_identifier) {
 836         case 0x00:
 837                 sprintf(buf+len, "Fibre Channel\n");
 838                 break;
 839         case 0x10:
 840                 sprintf(buf+len, "Parallel SCSI\n");
 841                 break;
 842         case 0x20:
 843                 sprintf(buf+len, "SSA\n");
 844                 break;
 845         case 0x30:
 846                 sprintf(buf+len, "IEEE 1394\n");
 847                 break;
 848         case 0x40:
 849                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 850                                 " Protocol\n");
 851                 break;
 852         case 0x50:
 853                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 854                 break;
 855         case 0x60:
 856                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 857                 break;
 858         case 0x70:
 859                 sprintf(buf+len, "Automation/Drive Interface Transport"
 860                                 " Protocol\n");
 861                 break;
 862         case 0x80:
 863                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 864                 break;
 865         default:
 866                 sprintf(buf+len, "Unknown 0x%02x\n",
 867                                 vpd->protocol_identifier);
 868                 break;
 869         }
 870
 871         if (p_buf)
 872                 strncpy(p_buf, buf, p_buf_len);
 873         else
 874                 pr_debug("%s", buf);
 875 }
 876
 877 void
 878 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 879 {
 880         /*
 881          * Check if the Protocol Identifier Valid (PIV) bit is set..
 882          *
 883          * from spc3r23.pdf section 7.5.1
 884          */
 885          if (page_83[1] & 0x80) {
 886                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 887                 vpd->protocol_identifier_set = 1;
 888                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 889         }
 890 }
 891 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 892
 893 int transport_dump_vpd_assoc(
 894         struct t10_vpd *vpd,
 895         unsigned char *p_buf,
 896         int p_buf_len)
 897 {
 898         unsigned char buf[VPD_TMP_BUF_SIZE];
 899         int ret = 0;
 900         int len;
 901
 902         memset(buf, 0, VPD_TMP_BUF_SIZE);
 903         len = sprintf(buf, "T10 VPD Identifier Association: ");
 904
 905         switch (vpd->association) {
 906         case 0x00:
 907                 sprintf(buf+len, "addressed logical unit\n");
 908                 break;
 909         case 0x10:
 910                 sprintf(buf+len, "target port\n");
 911                 break;
 912         case 0x20:
 913                 sprintf(buf+len, "SCSI target device\n");
 914                 break;
 915         default:
 916                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 917                 ret = -EINVAL;
 918                 break;
 919         }
 920
 921         if (p_buf)
 922                 strncpy(p_buf, buf, p_buf_len);
 923         else
 924                 pr_debug("%s", buf);
 925
 926         return ret;
 927 }
 928
 929 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 930 {
 931         /*
 932          * The VPD identification association..
 933          *
 934          * from spc3r23.pdf Section 7.6.3.1 Table 297
 935          */
 936         vpd->association = (page_83[1] & 0x30);
 937         return transport_dump_vpd_assoc(vpd, NULL, 0);
 938 }
 939 EXPORT_SYMBOL(transport_set_vpd_assoc);
 940
 941 int transport_dump_vpd_ident_type(
 942         struct t10_vpd *vpd,
 943         unsigned char *p_buf,
 944         int p_buf_len)
 945 {
 946         unsigned char buf[VPD_TMP_BUF_SIZE];
 947         int ret = 0;
 948         int len;
 949
 950         memset(buf, 0, VPD_TMP_BUF_SIZE);
 951         len = sprintf(buf, "T10 VPD Identifier Type: ");
 952
 953         switch (vpd->device_identifier_type) {
 954         case 0x00:
 955                 sprintf(buf+len, "Vendor specific\n");
 956                 break;
 957         case 0x01:
 958                 sprintf(buf+len, "T10 Vendor ID based\n");
 959                 break;
 960         case 0x02:
 961                 sprintf(buf+len, "EUI-64 based\n");
 962                 break;
 963         case 0x03:
 964                 sprintf(buf+len, "NAA\n");
 965                 break;
 966         case 0x04:
 967                 sprintf(buf+len, "Relative target port identifier\n");
 968                 break;
 969         case 0x08:
 970                 sprintf(buf+len, "SCSI name string\n");
 971                 break;
 972         default:
 973                 sprintf(buf+len, "Unsupported: 0x%02x\n",
 974                                 vpd->device_identifier_type);
 975                 ret = -EINVAL;
 976                 break;
 977         }
 978
 979         if (p_buf) {
 980                 if (p_buf_len < strlen(buf)+1)
 981                         return -EINVAL;
 982                 strncpy(p_buf, buf, p_buf_len);
 983         } else {
 984                 pr_debug("%s", buf);
 985         }
 986
 987         return ret;
 988 }
 989
 990 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
 991 {
 992         /*
 993          * The VPD identifier type..
 994          *
 995          * from spc3r23.pdf Section 7.6.3.1 Table 298
 996          */
 997         vpd->device_identifier_type = (page_83[1] & 0x0f);
 998         return transport_dump_vpd_ident_type(vpd, NULL, 0);
 999 }
1000 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1001
1002 int transport_dump_vpd_ident(
1003         struct t10_vpd *vpd,
1004         unsigned char *p_buf,
1005         int p_buf_len)
1006 {
1007         unsigned char buf[VPD_TMP_BUF_SIZE];
1008         int ret = 0;
1009
1010         memset(buf, 0, VPD_TMP_BUF_SIZE);
1011
1012         switch (vpd->device_identifier_code_set) {
1013         case 0x01: /* Binary */
1014                 snprintf(buf, sizeof(buf),
1015                         "T10 VPD Binary Device Identifier: %s\n",
1016                         &vpd->device_identifier[0]);
1017                 break;
1018         case 0x02: /* ASCII */
1019                 snprintf(buf, sizeof(buf),
1020                         "T10 VPD ASCII Device Identifier: %s\n",
1021                         &vpd->device_identifier[0]);
1022                 break;
1023         case 0x03: /* UTF-8 */
1024                 snprintf(buf, sizeof(buf),
1025                         "T10 VPD UTF-8 Device Identifier: %s\n",
1026                         &vpd->device_identifier[0]);
1027                 break;
1028         default:
1029                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1030                         " 0x%02x", vpd->device_identifier_code_set);
1031                 ret = -EINVAL;
1032                 break;
1033         }
1034
1035         if (p_buf)
1036                 strncpy(p_buf, buf, p_buf_len);
1037         else
1038                 pr_debug("%s", buf);
1039
1040         return ret;
1041 }
1042
1043 int
1044 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1045 {
1046         static const char hex_str[] = "0123456789abcdef";
1047         int j = 0, i = 4; /* offset to start of the identifier */
1048
1049         /*
1050          * The VPD Code Set (encoding)
1051          *
1052          * from spc3r23.pdf Section 7.6.3.1 Table 296
1053          */
1054         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1055         switch (vpd->device_identifier_code_set) {
1056         case 0x01: /* Binary */
1057                 vpd->device_identifier[j++] =
1058                                 hex_str[vpd->device_identifier_type];
1059                 while (i < (4 + page_83[3])) {
1060                         vpd->device_identifier[j++] =
1061                                 hex_str[(page_83[i] & 0xf0) >> 4];
1062                         vpd->device_identifier[j++] =
1063                                 hex_str[page_83[i] & 0x0f];
1064                         i++;
1065                 }
1066                 break;
1067         case 0x02: /* ASCII */
1068         case 0x03: /* UTF-8 */
1069                 while (i < (4 + page_83[3]))
1070                         vpd->device_identifier[j++] = page_83[i++];
1071                 break;
1072         default:
1073                 break;
1074         }
1075
1076         return transport_dump_vpd_ident(vpd, NULL, 0);
1077 }
1078 EXPORT_SYMBOL(transport_set_vpd_ident);
1079
1080 static sense_reason_t
1081 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1082                                unsigned int size)
1083 {
1084         u32 mtl;
1085
1086         if (!cmd->se_tfo->max_data_sg_nents)
1087                 return TCM_NO_SENSE;
1088         /*
1089          * Check if fabric enforced maximum SGL entries per I/O descriptor
1090          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1091          * residual_count and reduce original cmd->data_length to maximum
1092          * length based on single PAGE_SIZE entry scatter-lists.
1093          */
1094         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1095         if (cmd->data_length > mtl) {
1096                 /*
1097                  * If an existing CDB overflow is present, calculate new residual
1098                  * based on CDB size minus fabric maximum transfer length.
1099                  *
1100                  * If an existing CDB underflow is present, calculate new residual
1101                  * based on original cmd->data_length minus fabric maximum transfer
1102                  * length.
1103                  *
1104                  * Otherwise, set the underflow residual based on cmd->data_length
1105                  * minus fabric maximum transfer length.
1106                  */
1107                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1108                         cmd->residual_count = (size - mtl);
1109                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1110                         u32 orig_dl = size + cmd->residual_count;
1111                         cmd->residual_count = (orig_dl - mtl);
1112                 } else {
1113                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1114                         cmd->residual_count = (cmd->data_length - mtl);
1115                 }
1116                 cmd->data_length = mtl;
1117                 /*
1118                  * Reset sbc_check_prot() calculated protection payload
1119                  * length based upon the new smaller MTL.
1120                  */
1121                 if (cmd->prot_length) {
1122                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1123                         cmd->prot_length = dev->prot_length * sectors;
1124                 }
1125         }
1126         return TCM_NO_SENSE;
1127 }
1128
1129 sense_reason_t
1130 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1131 {
1132         struct se_device *dev = cmd->se_dev;
1133
1134         if (cmd->unknown_data_length) {
1135                 cmd->data_length = size;
1136         } else if (size != cmd->data_length) {
1137                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1138                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1139                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1140                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1141
1142                 if (cmd->data_direction == DMA_TO_DEVICE &&
1143                     cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1144                         pr_err("Rejecting underflow/overflow WRITE data\n");
1145                         return TCM_INVALID_CDB_FIELD;
1146                 }
1147                 /*
1148                  * Reject READ_* or WRITE_* with overflow/underflow for
1149                  * type SCF_SCSI_DATA_CDB.
1150                  */
1151                 if (dev->dev_attrib.block_size != 512)  {
1152                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1153                                 " CDB on non 512-byte sector setup subsystem"
1154                                 " plugin: %s\n", dev->transport->name);
1155                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1156                         return TCM_INVALID_CDB_FIELD;
1157                 }
1158                 /*
1159                  * For the overflow case keep the existing fabric provided
1160                  * ->data_length.  Otherwise for the underflow case, reset
1161                  * ->data_length to the smaller SCSI expected data transfer
1162                  * length.
1163                  */
1164                 if (size > cmd->data_length) {
1165                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1166                         cmd->residual_count = (size - cmd->data_length);
1167                 } else {
1168                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1169                         cmd->residual_count = (cmd->data_length - size);
1170                         cmd->data_length = size;
1171                 }
1172         }
1173
1174         return target_check_max_data_sg_nents(cmd, dev, size);
1175
1176 }
1177
1178 /*
1179  * Used by fabric modules containing a local struct se_cmd within their
1180  * fabric dependent per I/O descriptor.
1181  *
1182  * Preserves the value of @cmd->tag.
1183  */
1184 void transport_init_se_cmd(
1185         struct se_cmd *cmd,
1186         const struct target_core_fabric_ops *tfo,
1187         struct se_session *se_sess,
1188         u32 data_length,
1189         int data_direction,
1190         int task_attr,
1191         unsigned char *sense_buffer)
1192 {
1193         INIT_LIST_HEAD(&cmd->se_delayed_node);
1194         INIT_LIST_HEAD(&cmd->se_qf_node);
1195         INIT_LIST_HEAD(&cmd->se_cmd_list);
1196         INIT_LIST_HEAD(&cmd->state_list);
1197         init_completion(&cmd->t_transport_stop_comp);
1198         init_completion(&cmd->cmd_wait_comp);
1199         init_completion(&cmd->task_stop_comp);
1200         spin_lock_init(&cmd->t_state_lock);
1201         kref_init(&cmd->cmd_kref);
1202         cmd->transport_state = CMD_T_DEV_ACTIVE;
1203
1204         cmd->se_tfo = tfo;
1205         cmd->se_sess = se_sess;
1206         cmd->data_length = data_length;
1207         cmd->data_direction = data_direction;
1208         cmd->sam_task_attr = task_attr;
1209         cmd->sense_buffer = sense_buffer;
1210
1211         cmd->state_active = false;
1212 }
1213 EXPORT_SYMBOL(transport_init_se_cmd);
1214
1215 static sense_reason_t
1216 transport_check_alloc_task_attr(struct se_cmd *cmd)
1217 {
1218         struct se_device *dev = cmd->se_dev;
1219
1220         /*
1221          * Check if SAM Task Attribute emulation is enabled for this
1222          * struct se_device storage object
1223          */
1224         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1225                 return 0;
1226
1227         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1228                 pr_debug("SAM Task Attribute ACA"
1229                         " emulation is not supported\n");
1230                 return TCM_INVALID_CDB_FIELD;
1231         }
1232
1233         return 0;
1234 }
1235
1236 sense_reason_t
1237 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1238 {
1239         struct se_device *dev = cmd->se_dev;
1240         sense_reason_t ret;
1241
1242         /*
1243          * Ensure that the received CDB is less than the max (252 + 8) bytes
1244          * for VARIABLE_LENGTH_CMD
1245          */
1246         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1247                 pr_err("Received SCSI CDB with command_size: %d that"
1248                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1249                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1250                 return TCM_INVALID_CDB_FIELD;
1251         }
1252         /*
1253          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1254          * allocate the additional extended CDB buffer now..  Otherwise
1255          * setup the pointer from __t_task_cdb to t_task_cdb.
1256          */
1257         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1258                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1259                                                 GFP_KERNEL);
1260                 if (!cmd->t_task_cdb) {
1261                         pr_err("Unable to allocate cmd->t_task_cdb"
1262                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1263                                 scsi_command_size(cdb),
1264                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1265                         return TCM_OUT_OF_RESOURCES;
1266                 }
1267         } else
1268                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1269         /*
1270          * Copy the original CDB into cmd->
1271          */
1272         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1273
1274         trace_target_sequencer_start(cmd);
1275
1276         /*
1277          * Check for an existing UNIT ATTENTION condition
1278          */
1279         ret = target_scsi3_ua_check(cmd);
1280         if (ret)
1281                 return ret;
1282
1283         ret = target_alua_state_check(cmd);
1284         if (ret)
1285                 return ret;
1286
1287         ret = target_check_reservation(cmd);
1288         if (ret) {
1289                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1290                 return ret;
1291         }
1292
1293         ret = dev->transport->parse_cdb(cmd);
1294         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1295                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1296                                     cmd->se_tfo->get_fabric_name(),
1297                                     cmd->se_sess->se_node_acl->initiatorname,
1298                                     cmd->t_task_cdb[0]);
1299         if (ret)
1300                 return ret;
1301
1302         ret = transport_check_alloc_task_attr(cmd);
1303         if (ret)
1304                 return ret;
1305
1306         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1307         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1308         return 0;
1309 }
1310 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1311
1312 /*
1313  * Used by fabric module frontends to queue tasks directly.
1314  * May only be used from process context.
1315  */
1316 int transport_handle_cdb_direct(
1317         struct se_cmd *cmd)
1318 {
1319         sense_reason_t ret;
1320
1321         if (!cmd->se_lun) {
1322                 dump_stack();
1323                 pr_err("cmd->se_lun is NULL\n");
1324                 return -EINVAL;
1325         }
1326         if (in_interrupt()) {
1327                 dump_stack();
1328                 pr_err("transport_generic_handle_cdb cannot be called"
1329                                 " from interrupt context\n");
1330                 return -EINVAL;
1331         }
1332         /*
1333          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1334          * outstanding descriptors are handled correctly during shutdown via
1335          * transport_wait_for_tasks()
1336          *
1337          * Also, we don't take cmd->t_state_lock here as we only expect
1338          * this to be called for initial descriptor submission.
1339          */
1340         cmd->t_state = TRANSPORT_NEW_CMD;
1341         cmd->transport_state |= CMD_T_ACTIVE;
1342
1343         /*
1344          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1345          * so follow TRANSPORT_NEW_CMD processing thread context usage
1346          * and call transport_generic_request_failure() if necessary..
1347          */
1348         ret = transport_generic_new_cmd(cmd);
1349         if (ret)
1350                 transport_generic_request_failure(cmd, ret);
1351         return 0;
1352 }
1353 EXPORT_SYMBOL(transport_handle_cdb_direct);
1354
1355 sense_reason_t
1356 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1357                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1358 {
1359         if (!sgl || !sgl_count)
1360                 return 0;
1361
1362         /*
1363          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1364          * scatterlists already have been set to follow what the fabric
1365          * passes for the original expected data transfer length.
1366          */
1367         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1368                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1369                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1370                 return TCM_INVALID_CDB_FIELD;
1371         }
1372
1373         cmd->t_data_sg = sgl;
1374         cmd->t_data_nents = sgl_count;
1375         cmd->t_bidi_data_sg = sgl_bidi;
1376         cmd->t_bidi_data_nents = sgl_bidi_count;
1377
1378         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1379         return 0;
1380 }
1381
1382 /*
1383  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1384  *                       se_cmd + use pre-allocated SGL memory.
1385  *
1386  * @se_cmd: command descriptor to submit
1387  * @se_sess: associated se_sess for endpoint
1388  * @cdb: pointer to SCSI CDB
1389  * @sense: pointer to SCSI sense buffer
1390  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1391  * @data_length: fabric expected data transfer length
1392  * @task_addr: SAM task attribute
1393  * @data_dir: DMA data direction
1394  * @flags: flags for command submission from target_sc_flags_tables
1395  * @sgl: struct scatterlist memory for unidirectional mapping
1396  * @sgl_count: scatterlist count for unidirectional mapping
1397  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1398  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1399  * @sgl_prot: struct scatterlist memory protection information
1400  * @sgl_prot_count: scatterlist count for protection information
1401  *
1402  * Task tags are supported if the caller has set @se_cmd->tag.
1403  *
1404  * Returns non zero to signal active I/O shutdown failure.  All other
1405  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1406  * but still return zero here.
1407  *
1408  * This may only be called from process context, and also currently
1409  * assumes internal allocation of fabric payload buffer by target-core.
1410  */
1411 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1412                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1413                 u32 data_length, int task_attr, int data_dir, int flags,
1414                 struct scatterlist *sgl, u32 sgl_count,
1415                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1416                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1417 {
1418         struct se_portal_group *se_tpg;
1419         sense_reason_t rc;
1420         int ret;
1421
1422         se_tpg = se_sess->se_tpg;
1423         BUG_ON(!se_tpg);
1424         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1425         BUG_ON(in_interrupt());
1426         /*
1427          * Initialize se_cmd for target operation.  From this point
1428          * exceptions are handled by sending exception status via
1429          * target_core_fabric_ops->queue_status() callback
1430          */
1431         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1432                                 data_length, data_dir, task_attr, sense);
1433         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1434                 se_cmd->unknown_data_length = 1;
1435         /*
1436          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1437          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1438          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1439          * kref_put() to happen during fabric packet acknowledgement.
1440          */
1441         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1442         if (ret)
1443                 return ret;
1444         /*
1445          * Signal bidirectional data payloads to target-core
1446          */
1447         if (flags & TARGET_SCF_BIDI_OP)
1448                 se_cmd->se_cmd_flags |= SCF_BIDI;
1449         /*
1450          * Locate se_lun pointer and attach it to struct se_cmd
1451          */
1452         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1453         if (rc) {
1454                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1455                 target_put_sess_cmd(se_cmd);
1456                 return 0;
1457         }
1458
1459         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1460         if (rc != 0) {
1461                 transport_generic_request_failure(se_cmd, rc);
1462                 return 0;
1463         }
1464
1465         /*
1466          * Save pointers for SGLs containing protection information,
1467          * if present.
1468          */
1469         if (sgl_prot_count) {
1470                 se_cmd->t_prot_sg = sgl_prot;
1471                 se_cmd->t_prot_nents = sgl_prot_count;
1472                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1473         }
1474
1475         /*
1476          * When a non zero sgl_count has been passed perform SGL passthrough
1477          * mapping for pre-allocated fabric memory instead of having target
1478          * core perform an internal SGL allocation..
1479          */
1480         if (sgl_count != 0) {
1481                 BUG_ON(!sgl);
1482
1483                 /*
1484                  * A work-around for tcm_loop as some userspace code via
1485                  * scsi-generic do not memset their associated read buffers,
1486                  * so go ahead and do that here for type non-data CDBs.  Also
1487                  * note that this is currently guaranteed to be a single SGL
1488                  * for this case by target core in target_setup_cmd_from_cdb()
1489                  * -> transport_generic_cmd_sequencer().
1490                  */
1491                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1492                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1493                         unsigned char *buf = NULL;
1494
1495                         if (sgl)
1496                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1497
1498                         if (buf) {
1499                                 memset(buf, 0, sgl->length);
1500                                 kunmap(sg_page(sgl));
1501                         }
1502                 }
1503
1504                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1505                                 sgl_bidi, sgl_bidi_count);
1506                 if (rc != 0) {
1507                         transport_generic_request_failure(se_cmd, rc);
1508                         return 0;
1509                 }
1510         }
1511
1512         /*
1513          * Check if we need to delay processing because of ALUA
1514          * Active/NonOptimized primary access state..
1515          */
1516         core_alua_check_nonop_delay(se_cmd);
1517
1518         transport_handle_cdb_direct(se_cmd);
1519         return 0;
1520 }
1521 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1522
1523 /*
1524  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1525  *
1526  * @se_cmd: command descriptor to submit
1527  * @se_sess: associated se_sess for endpoint
1528  * @cdb: pointer to SCSI CDB
1529  * @sense: pointer to SCSI sense buffer
1530  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1531  * @data_length: fabric expected data transfer length
1532  * @task_addr: SAM task attribute
1533  * @data_dir: DMA data direction
1534  * @flags: flags for command submission from target_sc_flags_tables
1535  *
1536  * Task tags are supported if the caller has set @se_cmd->tag.
1537  *
1538  * Returns non zero to signal active I/O shutdown failure.  All other
1539  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1540  * but still return zero here.
1541  *
1542  * This may only be called from process context, and also currently
1543  * assumes internal allocation of fabric payload buffer by target-core.
1544  *
1545  * It also assumes interal target core SGL memory allocation.
1546  */
1547 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1548                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1549                 u32 data_length, int task_attr, int data_dir, int flags)
1550 {
1551         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1552                         unpacked_lun, data_length, task_attr, data_dir,
1553                         flags, NULL, 0, NULL, 0, NULL, 0);
1554 }
1555 EXPORT_SYMBOL(target_submit_cmd);
1556
1557 static void target_complete_tmr_failure(struct work_struct *work)
1558 {
1559         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1560
1561         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1562         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1563
1564         transport_cmd_check_stop_to_fabric(se_cmd);
1565 }
1566
1567 /**
1568  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1569  *                     for TMR CDBs
1570  *
1571  * @se_cmd: command descriptor to submit
1572  * @se_sess: associated se_sess for endpoint
1573  * @sense: pointer to SCSI sense buffer
1574  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1575  * @fabric_context: fabric context for TMR req
1576  * @tm_type: Type of TM request
1577  * @gfp: gfp type for caller
1578  * @tag: referenced task tag for TMR_ABORT_TASK
1579  * @flags: submit cmd flags
1580  *
1581  * Callable from all contexts.
1582  **/
1583
1584 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1585                 unsigned char *sense, u64 unpacked_lun,
1586                 void *fabric_tmr_ptr, unsigned char tm_type,
1587                 gfp_t gfp, u64 tag, int flags)
1588 {
1589         struct se_portal_group *se_tpg;
1590         int ret;
1591
1592         se_tpg = se_sess->se_tpg;
1593         BUG_ON(!se_tpg);
1594
1595         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1596                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1597         /*
1598          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1599          * allocation failure.
1600          */
1601         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1602         if (ret < 0)
1603                 return -ENOMEM;
1604
1605         if (tm_type == TMR_ABORT_TASK)
1606                 se_cmd->se_tmr_req->ref_task_tag = tag;
1607
1608         /* See target_submit_cmd for commentary */
1609         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1610         if (ret) {
1611                 core_tmr_release_req(se_cmd->se_tmr_req);
1612                 return ret;
1613         }
1614
1615         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1616         if (ret) {
1617                 /*
1618                  * For callback during failure handling, push this work off
1619                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1620                  */
1621                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1622                 schedule_work(&se_cmd->work);
1623                 return 0;
1624         }
1625         transport_generic_handle_tmr(se_cmd);
1626         return 0;
1627 }
1628 EXPORT_SYMBOL(target_submit_tmr);
1629
1630 /*
1631  * If the cmd is active, request it to be stopped and sleep until it
1632  * has completed.
1633  */
1634 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1635         __releases(&cmd->t_state_lock)
1636         __acquires(&cmd->t_state_lock)
1637 {
1638         bool was_active = false;
1639
1640         if (cmd->transport_state & CMD_T_BUSY) {
1641                 cmd->transport_state |= CMD_T_REQUEST_STOP;
1642                 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1643
1644                 pr_debug("cmd %p waiting to complete\n", cmd);
1645                 wait_for_completion(&cmd->task_stop_comp);
1646                 pr_debug("cmd %p stopped successfully\n", cmd);
1647
1648                 spin_lock_irqsave(&cmd->t_state_lock, *flags);
1649                 cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1650                 cmd->transport_state &= ~CMD_T_BUSY;
1651                 was_active = true;
1652         }
1653
1654         return was_active;
1655 }
1656
1657 /*
1658  * Handle SAM-esque emulation for generic transport request failures.
1659  */
1660 void transport_generic_request_failure(struct se_cmd *cmd,
1661                 sense_reason_t sense_reason)
1662 {
1663         int ret = 0;
1664
1665         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1666                 " CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1667         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1668                 cmd->se_tfo->get_cmd_state(cmd),
1669                 cmd->t_state, sense_reason);
1670         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1671                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1672                 (cmd->transport_state & CMD_T_STOP) != 0,
1673                 (cmd->transport_state & CMD_T_SENT) != 0);
1674
1675         /*
1676          * For SAM Task Attribute emulation for failed struct se_cmd
1677          */
1678         transport_complete_task_attr(cmd);
1679         /*
1680          * Handle special case for COMPARE_AND_WRITE failure, where the
1681          * callback is expected to drop the per device ->caw_sem.
1682          */
1683         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1684              cmd->transport_complete_callback)
1685                 cmd->transport_complete_callback(cmd, false);
1686
1687         switch (sense_reason) {
1688         case TCM_NON_EXISTENT_LUN:
1689         case TCM_UNSUPPORTED_SCSI_OPCODE:
1690         case TCM_INVALID_CDB_FIELD:
1691         case TCM_INVALID_PARAMETER_LIST:
1692         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1693         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1694         case TCM_UNKNOWN_MODE_PAGE:
1695         case TCM_WRITE_PROTECTED:
1696         case TCM_ADDRESS_OUT_OF_RANGE:
1697         case TCM_CHECK_CONDITION_ABORT_CMD:
1698         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1699         case TCM_CHECK_CONDITION_NOT_READY:
1700         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1701         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1702         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1703                 break;
1704         case TCM_OUT_OF_RESOURCES:
1705                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1706                 break;
1707         case TCM_RESERVATION_CONFLICT:
1708                 /*
1709                  * No SENSE Data payload for this case, set SCSI Status
1710                  * and queue the response to $FABRIC_MOD.
1711                  *
1712                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1713                  */
1714                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1715                 /*
1716                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1717                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1718                  * CONFLICT STATUS.
1719                  *
1720                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1721                  */
1722                 if (cmd->se_sess &&
1723                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1724                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1725                                                cmd->orig_fe_lun, 0x2C,
1726                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1727                 }
1728                 trace_target_cmd_complete(cmd);
1729                 ret = cmd->se_tfo->queue_status(cmd);
1730                 if (ret == -EAGAIN || ret == -ENOMEM)
1731                         goto queue_full;
1732                 goto check_stop;
1733         default:
1734                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1735                         cmd->t_task_cdb[0], sense_reason);
1736                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1737                 break;
1738         }
1739
1740         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1741         if (ret == -EAGAIN || ret == -ENOMEM)
1742                 goto queue_full;
1743
1744 check_stop:
1745         transport_lun_remove_cmd(cmd);
1746         transport_cmd_check_stop_to_fabric(cmd);
1747         return;
1748
1749 queue_full:
1750         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1751         transport_handle_queue_full(cmd, cmd->se_dev);
1752 }
1753 EXPORT_SYMBOL(transport_generic_request_failure);
1754
1755 void __target_execute_cmd(struct se_cmd *cmd)
1756 {
1757         sense_reason_t ret;
1758
1759         if (cmd->execute_cmd) {
1760                 ret = cmd->execute_cmd(cmd);
1761                 if (ret) {
1762                         spin_lock_irq(&cmd->t_state_lock);
1763                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1764                         spin_unlock_irq(&cmd->t_state_lock);
1765
1766                         transport_generic_request_failure(cmd, ret);
1767                 }
1768         }
1769 }
1770
1771 static int target_write_prot_action(struct se_cmd *cmd)
1772 {
1773         u32 sectors;
1774         /*
1775          * Perform WRITE_INSERT of PI using software emulation when backend
1776          * device has PI enabled, if the transport has not already generated
1777          * PI using hardware WRITE_INSERT offload.
1778          */
1779         switch (cmd->prot_op) {
1780         case TARGET_PROT_DOUT_INSERT:
1781                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1782                         sbc_dif_generate(cmd);
1783                 break;
1784         case TARGET_PROT_DOUT_STRIP:
1785                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1786                         break;
1787
1788                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1789                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1790                                              sectors, 0, cmd->t_prot_sg, 0);
1791                 if (unlikely(cmd->pi_err)) {
1792                         spin_lock_irq(&cmd->t_state_lock);
1793                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1794                         spin_unlock_irq(&cmd->t_state_lock);
1795                         transport_generic_request_failure(cmd, cmd->pi_err);
1796                         return -1;
1797                 }
1798                 break;
1799         default:
1800                 break;
1801         }
1802
1803         return 0;
1804 }
1805
1806 static bool target_handle_task_attr(struct se_cmd *cmd)
1807 {
1808         struct se_device *dev = cmd->se_dev;
1809
1810         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1811                 return false;
1812
1813         /*
1814          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1815          * to allow the passed struct se_cmd list of tasks to the front of the list.
1816          */
1817         switch (cmd->sam_task_attr) {
1818         case TCM_HEAD_TAG:
1819                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1820                          cmd->t_task_cdb[0]);
1821                 return false;
1822         case TCM_ORDERED_TAG:
1823                 atomic_inc_mb(&dev->dev_ordered_sync);
1824
1825                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1826                          cmd->t_task_cdb[0]);
1827
1828                 /*
1829                  * Execute an ORDERED command if no other older commands
1830                  * exist that need to be completed first.
1831                  */
1832                 if (!atomic_read(&dev->simple_cmds))
1833                         return false;
1834                 break;
1835         default:
1836                 /*
1837                  * For SIMPLE and UNTAGGED Task Attribute commands
1838                  */
1839                 atomic_inc_mb(&dev->simple_cmds);
1840                 break;
1841         }
1842
1843         if (atomic_read(&dev->dev_ordered_sync) == 0)
1844                 return false;
1845
1846         spin_lock(&dev->delayed_cmd_lock);
1847         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1848         spin_unlock(&dev->delayed_cmd_lock);
1849
1850         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1851                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1852         return true;
1853 }
1854
1855 void target_execute_cmd(struct se_cmd *cmd)
1856 {
1857         /*
1858          * If the received CDB has aleady been aborted stop processing it here.
1859          */
1860         if (transport_check_aborted_status(cmd, 1))
1861                 return;
1862
1863         /*
1864          * Determine if frontend context caller is requesting the stopping of
1865          * this command for frontend exceptions.
1866          */
1867         spin_lock_irq(&cmd->t_state_lock);
1868         if (cmd->transport_state & CMD_T_STOP) {
1869                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1870                         __func__, __LINE__, cmd->tag);
1871
1872                 spin_unlock_irq(&cmd->t_state_lock);
1873                 complete_all(&cmd->t_transport_stop_comp);
1874                 return;
1875         }
1876
1877         cmd->t_state = TRANSPORT_PROCESSING;
1878         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1879         spin_unlock_irq(&cmd->t_state_lock);
1880
1881         if (target_write_prot_action(cmd))
1882                 return;
1883
1884         if (target_handle_task_attr(cmd)) {
1885                 spin_lock_irq(&cmd->t_state_lock);
1886                 cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1887                 spin_unlock_irq(&cmd->t_state_lock);
1888                 return;
1889         }
1890
1891         __target_execute_cmd(cmd);
1892 }
1893 EXPORT_SYMBOL(target_execute_cmd);
1894
1895 /*
1896  * Process all commands up to the last received ORDERED task attribute which
1897  * requires another blocking boundary
1898  */
1899 static void target_restart_delayed_cmds(struct se_device *dev)
1900 {
1901         for (;;) {
1902                 struct se_cmd *cmd;
1903
1904                 spin_lock(&dev->delayed_cmd_lock);
1905                 if (list_empty(&dev->delayed_cmd_list)) {
1906                         spin_unlock(&dev->delayed_cmd_lock);
1907                         break;
1908                 }
1909
1910                 cmd = list_entry(dev->delayed_cmd_list.next,
1911                                  struct se_cmd, se_delayed_node);
1912                 list_del(&cmd->se_delayed_node);
1913                 spin_unlock(&dev->delayed_cmd_lock);
1914
1915                 __target_execute_cmd(cmd);
1916
1917                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1918                         break;
1919         }
1920 }
1921
1922 /*
1923  * Called from I/O completion to determine which dormant/delayed
1924  * and ordered cmds need to have their tasks added to the execution queue.
1925  */
1926 static void transport_complete_task_attr(struct se_cmd *cmd)
1927 {
1928         struct se_device *dev = cmd->se_dev;
1929
1930         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1931                 return;
1932
1933         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1934                 atomic_dec_mb(&dev->simple_cmds);
1935                 dev->dev_cur_ordered_id++;
1936                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for SIMPLE\n",
1937                          dev->dev_cur_ordered_id);
1938         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1939                 dev->dev_cur_ordered_id++;
1940                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1941                          dev->dev_cur_ordered_id);
1942         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1943                 atomic_dec_mb(&dev->dev_ordered_sync);
1944
1945                 dev->dev_cur_ordered_id++;
1946                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1947                          dev->dev_cur_ordered_id);
1948         }
1949
1950         target_restart_delayed_cmds(dev);
1951 }
1952
1953 static void transport_complete_qf(struct se_cmd *cmd)
1954 {
1955         int ret = 0;
1956
1957         transport_complete_task_attr(cmd);
1958
1959         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1960                 trace_target_cmd_complete(cmd);
1961                 ret = cmd->se_tfo->queue_status(cmd);
1962                 goto out;
1963         }
1964
1965         switch (cmd->data_direction) {
1966         case DMA_FROM_DEVICE:
1967                 trace_target_cmd_complete(cmd);
1968                 ret = cmd->se_tfo->queue_data_in(cmd);
1969                 break;
1970         case DMA_TO_DEVICE:
1971                 if (cmd->se_cmd_flags & SCF_BIDI) {
1972                         ret = cmd->se_tfo->queue_data_in(cmd);
1973                         break;
1974                 }
1975                 /* Fall through for DMA_TO_DEVICE */
1976         case DMA_NONE:
1977                 trace_target_cmd_complete(cmd);
1978                 ret = cmd->se_tfo->queue_status(cmd);
1979                 break;
1980         default:
1981                 break;
1982         }
1983
1984 out:
1985         if (ret < 0) {
1986                 transport_handle_queue_full(cmd, cmd->se_dev);
1987                 return;
1988         }
1989         transport_lun_remove_cmd(cmd);
1990         transport_cmd_check_stop_to_fabric(cmd);
1991 }
1992
1993 static void transport_handle_queue_full(
1994         struct se_cmd *cmd,
1995         struct se_device *dev)
1996 {
1997         spin_lock_irq(&dev->qf_cmd_lock);
1998         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1999         atomic_inc_mb(&dev->dev_qf_count);
2000         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2001
2002         schedule_work(&cmd->se_dev->qf_work_queue);
2003 }
2004
2005 static bool target_read_prot_action(struct se_cmd *cmd)
2006 {
2007         switch (cmd->prot_op) {
2008         case TARGET_PROT_DIN_STRIP:
2009                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2010                         u32 sectors = cmd->data_length >>
2011                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2012
2013                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2014                                                      sectors, 0, cmd->t_prot_sg,
2015                                                      0);
2016                         if (cmd->pi_err)
2017                                 return true;
2018                 }
2019                 break;
2020         case TARGET_PROT_DIN_INSERT:
2021                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2022                         break;
2023
2024                 sbc_dif_generate(cmd);
2025                 break;
2026         default:
2027                 break;
2028         }
2029
2030         return false;
2031 }
2032
2033 static void target_complete_ok_work(struct work_struct *work)
2034 {
2035         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2036         int ret;
2037
2038         /*
2039          * Check if we need to move delayed/dormant tasks from cmds on the
2040          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2041          * Attribute.
2042          */
2043         transport_complete_task_attr(cmd);
2044
2045         /*
2046          * Check to schedule QUEUE_FULL work, or execute an existing
2047          * cmd->transport_qf_callback()
2048          */
2049         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2050                 schedule_work(&cmd->se_dev->qf_work_queue);
2051
2052         /*
2053          * Check if we need to send a sense buffer from
2054          * the struct se_cmd in question.
2055          */
2056         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2057                 WARN_ON(!cmd->scsi_status);
2058                 ret = transport_send_check_condition_and_sense(
2059                                         cmd, 0, 1);
2060                 if (ret == -EAGAIN || ret == -ENOMEM)
2061                         goto queue_full;
2062
2063                 transport_lun_remove_cmd(cmd);
2064                 transport_cmd_check_stop_to_fabric(cmd);
2065                 return;
2066         }
2067         /*
2068          * Check for a callback, used by amongst other things
2069          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2070          */
2071         if (cmd->transport_complete_callback) {
2072                 sense_reason_t rc;
2073
2074                 rc = cmd->transport_complete_callback(cmd, true);
2075                 if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
2076                         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2077                             !cmd->data_length)
2078                                 goto queue_rsp;
2079
2080                         return;
2081                 } else if (rc) {
2082                         ret = transport_send_check_condition_and_sense(cmd,
2083                                                 rc, 0);
2084                         if (ret == -EAGAIN || ret == -ENOMEM)
2085                                 goto queue_full;
2086
2087                         transport_lun_remove_cmd(cmd);
2088                         transport_cmd_check_stop_to_fabric(cmd);
2089                         return;
2090                 }
2091         }
2092
2093 queue_rsp:
2094         switch (cmd->data_direction) {
2095         case DMA_FROM_DEVICE:
2096                 atomic_long_add(cmd->data_length,
2097                                 &cmd->se_lun->lun_stats.tx_data_octets);
2098                 /*
2099                  * Perform READ_STRIP of PI using software emulation when
2100                  * backend had PI enabled, if the transport will not be
2101                  * performing hardware READ_STRIP offload.
2102                  */
2103                 if (target_read_prot_action(cmd)) {
2104                         ret = transport_send_check_condition_and_sense(cmd,
2105                                                 cmd->pi_err, 0);
2106                         if (ret == -EAGAIN || ret == -ENOMEM)
2107                                 goto queue_full;
2108
2109                         transport_lun_remove_cmd(cmd);
2110                         transport_cmd_check_stop_to_fabric(cmd);
2111                         return;
2112                 }
2113
2114                 trace_target_cmd_complete(cmd);
2115                 ret = cmd->se_tfo->queue_data_in(cmd);
2116                 if (ret == -EAGAIN || ret == -ENOMEM)
2117                         goto queue_full;
2118                 break;
2119         case DMA_TO_DEVICE:
2120                 atomic_long_add(cmd->data_length,
2121                                 &cmd->se_lun->lun_stats.rx_data_octets);
2122                 /*
2123                  * Check if we need to send READ payload for BIDI-COMMAND
2124                  */
2125                 if (cmd->se_cmd_flags & SCF_BIDI) {
2126                         atomic_long_add(cmd->data_length,
2127                                         &cmd->se_lun->lun_stats.tx_data_octets);
2128                         ret = cmd->se_tfo->queue_data_in(cmd);
2129                         if (ret == -EAGAIN || ret == -ENOMEM)
2130                                 goto queue_full;
2131                         break;
2132                 }
2133                 /* Fall through for DMA_TO_DEVICE */
2134         case DMA_NONE:
2135                 trace_target_cmd_complete(cmd);
2136                 ret = cmd->se_tfo->queue_status(cmd);
2137                 if (ret == -EAGAIN || ret == -ENOMEM)
2138                         goto queue_full;
2139                 break;
2140         default:
2141                 break;
2142         }
2143
2144         transport_lun_remove_cmd(cmd);
2145         transport_cmd_check_stop_to_fabric(cmd);
2146         return;
2147
2148 queue_full:
2149         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2150                 " data_direction: %d\n", cmd, cmd->data_direction);
2151         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2152         transport_handle_queue_full(cmd, cmd->se_dev);
2153 }
2154
2155 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2156 {
2157         struct scatterlist *sg;
2158         int count;
2159
2160         for_each_sg(sgl, sg, nents, count)
2161                 __free_page(sg_page(sg));
2162
2163         kfree(sgl);
2164 }
2165
2166 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2167 {
2168         /*
2169          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2170          * emulation, and free + reset pointers if necessary..
2171          */
2172         if (!cmd->t_data_sg_orig)
2173                 return;
2174
2175         kfree(cmd->t_data_sg);
2176         cmd->t_data_sg = cmd->t_data_sg_orig;
2177         cmd->t_data_sg_orig = NULL;
2178         cmd->t_data_nents = cmd->t_data_nents_orig;
2179         cmd->t_data_nents_orig = 0;
2180 }
2181
2182 static inline void transport_free_pages(struct se_cmd *cmd)
2183 {
2184         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2185                 transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2186                 cmd->t_prot_sg = NULL;
2187                 cmd->t_prot_nents = 0;
2188         }
2189
2190         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2191                 /*
2192                  * Release special case READ buffer payload required for
2193                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2194                  */
2195                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2196                         transport_free_sgl(cmd->t_bidi_data_sg,
2197                                            cmd->t_bidi_data_nents);
2198                         cmd->t_bidi_data_sg = NULL;
2199                         cmd->t_bidi_data_nents = 0;
2200                 }
2201                 transport_reset_sgl_orig(cmd);
2202                 return;
2203         }
2204         transport_reset_sgl_orig(cmd);
2205
2206         transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2207         cmd->t_data_sg = NULL;
2208         cmd->t_data_nents = 0;
2209
2210         transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2211         cmd->t_bidi_data_sg = NULL;
2212         cmd->t_bidi_data_nents = 0;
2213 }
2214
2215 /**
2216  * transport_release_cmd - free a command
2217  * @cmd:       command to free
2218  *
2219  * This routine unconditionally frees a command, and reference counting
2220  * or list removal must be done in the caller.
2221  */
2222 static int transport_release_cmd(struct se_cmd *cmd)
2223 {
2224         BUG_ON(!cmd->se_tfo);
2225
2226         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2227                 core_tmr_release_req(cmd->se_tmr_req);
2228         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2229                 kfree(cmd->t_task_cdb);
2230         /*
2231          * If this cmd has been setup with target_get_sess_cmd(), drop
2232          * the kref and call ->release_cmd() in kref callback.
2233          */
2234         return target_put_sess_cmd(cmd);
2235 }
2236
2237 /**
2238  * transport_put_cmd - release a reference to a command
2239  * @cmd:       command to release
2240  *
2241  * This routine releases our reference to the command and frees it if possible.
2242  */
2243 static int transport_put_cmd(struct se_cmd *cmd)
2244 {
2245         transport_free_pages(cmd);
2246         return transport_release_cmd(cmd);
2247 }
2248
2249 void *transport_kmap_data_sg(struct se_cmd *cmd)
2250 {
2251         struct scatterlist *sg = cmd->t_data_sg;
2252         struct page **pages;
2253         int i;
2254
2255         /*
2256          * We need to take into account a possible offset here for fabrics like
2257          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2258          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2259          */
2260         if (!cmd->t_data_nents)
2261                 return NULL;
2262
2263         BUG_ON(!sg);
2264         if (cmd->t_data_nents == 1)
2265                 return kmap(sg_page(sg)) + sg->offset;
2266
2267         /* >1 page. use vmap */
2268         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2269         if (!pages)
2270                 return NULL;
2271
2272         /* convert sg[] to pages[] */
2273         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2274                 pages[i] = sg_page(sg);
2275         }
2276
2277         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2278         kfree(pages);
2279         if (!cmd->t_data_vmap)
2280                 return NULL;
2281
2282         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2283 }
2284 EXPORT_SYMBOL(transport_kmap_data_sg);
2285
2286 void transport_kunmap_data_sg(struct se_cmd *cmd)
2287 {
2288         if (!cmd->t_data_nents) {
2289                 return;
2290         } else if (cmd->t_data_nents == 1) {
2291                 kunmap(sg_page(cmd->t_data_sg));
2292                 return;
2293         }
2294
2295         vunmap(cmd->t_data_vmap);
2296         cmd->t_data_vmap = NULL;
2297 }
2298 EXPORT_SYMBOL(transport_kunmap_data_sg);
2299
2300 int
2301 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2302                  bool zero_page)
2303 {
2304         struct scatterlist *sg;
2305         struct page *page;
2306         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2307         unsigned int nent;
2308         int i = 0;
2309
2310         nent = DIV_ROUND_UP(length, PAGE_SIZE);
2311         sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2312         if (!sg)
2313                 return -ENOMEM;
2314
2315         sg_init_table(sg, nent);
2316
2317         while (length) {
2318                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2319                 page = alloc_page(GFP_KERNEL | zero_flag);
2320                 if (!page)
2321                         goto out;
2322
2323                 sg_set_page(&sg[i], page, page_len, 0);
2324                 length -= page_len;
2325                 i++;
2326         }
2327         *sgl = sg;
2328         *nents = nent;
2329         return 0;
2330
2331 out:
2332         while (i > 0) {
2333                 i--;
2334                 __free_page(sg_page(&sg[i]));
2335         }
2336         kfree(sg);
2337         return -ENOMEM;
2338 }
2339
2340 /*
2341  * Allocate any required resources to execute the command.  For writes we
2342  * might not have the payload yet, so notify the fabric via a call to
2343  * ->write_pending instead. Otherwise place it on the execution queue.
2344  */
2345 sense_reason_t
2346 transport_generic_new_cmd(struct se_cmd *cmd)
2347 {
2348         int ret = 0;
2349         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2350
2351         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2352             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2353                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2354                                        cmd->prot_length, true);
2355                 if (ret < 0)
2356                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2357         }
2358
2359         /*
2360          * Determine is the TCM fabric module has already allocated physical
2361          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2362          * beforehand.
2363          */
2364         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2365             cmd->data_length) {
2366
2367                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2368                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2369                         u32 bidi_length;
2370
2371                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2372                                 bidi_length = cmd->t_task_nolb *
2373                                               cmd->se_dev->dev_attrib.block_size;
2374                         else
2375                                 bidi_length = cmd->data_length;
2376
2377                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2378                                                &cmd->t_bidi_data_nents,
2379                                                bidi_length, zero_flag);
2380                         if (ret < 0)
2381                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2382                 }
2383
2384                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2385                                        cmd->data_length, zero_flag);
2386                 if (ret < 0)
2387                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2388         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2389                     cmd->data_length) {
2390                 /*
2391                  * Special case for COMPARE_AND_WRITE with fabrics
2392                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2393                  */
2394                 u32 caw_length = cmd->t_task_nolb *
2395                                  cmd->se_dev->dev_attrib.block_size;
2396
2397                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2398                                        &cmd->t_bidi_data_nents,
2399                                        caw_length, zero_flag);
2400                 if (ret < 0)
2401                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2402         }
2403         /*
2404          * If this command is not a write we can execute it right here,
2405          * for write buffers we need to notify the fabric driver first
2406          * and let it call back once the write buffers are ready.
2407          */
2408         target_add_to_state_list(cmd);
2409         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2410                 target_execute_cmd(cmd);
2411                 return 0;
2412         }
2413         transport_cmd_check_stop(cmd, false, true);
2414
2415         ret = cmd->se_tfo->write_pending(cmd);
2416         if (ret == -EAGAIN || ret == -ENOMEM)
2417                 goto queue_full;
2418
2419         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2420         WARN_ON(ret);
2421
2422         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2423
2424 queue_full:
2425         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2426         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2427         transport_handle_queue_full(cmd, cmd->se_dev);
2428         return 0;
2429 }
2430 EXPORT_SYMBOL(transport_generic_new_cmd);
2431
2432 static void transport_write_pending_qf(struct se_cmd *cmd)
2433 {
2434         int ret;
2435
2436         ret = cmd->se_tfo->write_pending(cmd);
2437         if (ret == -EAGAIN || ret == -ENOMEM) {
2438                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2439                          cmd);
2440                 transport_handle_queue_full(cmd, cmd->se_dev);
2441         }
2442 }
2443
2444 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2445 {
2446         unsigned long flags;
2447         int ret = 0;
2448
2449         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2450                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2451                          transport_wait_for_tasks(cmd);
2452
2453                 ret = transport_release_cmd(cmd);
2454         } else {
2455                 if (wait_for_tasks)
2456                         transport_wait_for_tasks(cmd);
2457                 /*
2458                  * Handle WRITE failure case where transport_generic_new_cmd()
2459                  * has already added se_cmd to state_list, but fabric has
2460                  * failed command before I/O submission.
2461                  */
2462                 if (cmd->state_active) {
2463                         spin_lock_irqsave(&cmd->t_state_lock, flags);
2464                         target_remove_from_state_list(cmd);
2465                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2466                 }
2467
2468                 if (cmd->se_lun)
2469                         transport_lun_remove_cmd(cmd);
2470
2471                 ret = transport_put_cmd(cmd);
2472         }
2473         return ret;
2474 }
2475 EXPORT_SYMBOL(transport_generic_free_cmd);
2476
2477 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2478  * @se_cmd:     command descriptor to add
2479  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2480  */
2481 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2482 {
2483         struct se_session *se_sess = se_cmd->se_sess;
2484         unsigned long flags;
2485         int ret = 0;
2486
2487         /*
2488          * Add a second kref if the fabric caller is expecting to handle
2489          * fabric acknowledgement that requires two target_put_sess_cmd()
2490          * invocations before se_cmd descriptor release.
2491          */
2492         if (ack_kref)
2493                 kref_get(&se_cmd->cmd_kref);
2494
2495         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2496         if (se_sess->sess_tearing_down) {
2497                 ret = -ESHUTDOWN;
2498                 goto out;
2499         }
2500         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2501 out:
2502         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2503
2504         if (ret && ack_kref)
2505                 target_put_sess_cmd(se_cmd);
2506
2507         return ret;
2508 }
2509 EXPORT_SYMBOL(target_get_sess_cmd);
2510
2511 static void target_release_cmd_kref(struct kref *kref)
2512                 __releases(&se_cmd->se_sess->sess_cmd_lock)
2513 {
2514         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2515         struct se_session *se_sess = se_cmd->se_sess;
2516
2517         if (list_empty(&se_cmd->se_cmd_list)) {
2518                 spin_unlock(&se_sess->sess_cmd_lock);
2519                 se_cmd->se_tfo->release_cmd(se_cmd);
2520                 return;
2521         }
2522         if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2523                 spin_unlock(&se_sess->sess_cmd_lock);
2524                 complete(&se_cmd->cmd_wait_comp);
2525                 return;
2526         }
2527         list_del(&se_cmd->se_cmd_list);
2528         spin_unlock(&se_sess->sess_cmd_lock);
2529
2530         se_cmd->se_tfo->release_cmd(se_cmd);
2531 }
2532
2533 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2534  * @se_cmd:     command descriptor to drop
2535  */
2536 int target_put_sess_cmd(struct se_cmd *se_cmd)
2537 {
2538         struct se_session *se_sess = se_cmd->se_sess;
2539
2540         if (!se_sess) {
2541                 se_cmd->se_tfo->release_cmd(se_cmd);
2542                 return 1;
2543         }
2544         return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2545                         &se_sess->sess_cmd_lock);
2546 }
2547 EXPORT_SYMBOL(target_put_sess_cmd);
2548
2549 /* target_sess_cmd_list_set_waiting - Flag all commands in
2550  *         sess_cmd_list to complete cmd_wait_comp.  Set
2551  *         sess_tearing_down so no more commands are queued.
2552  * @se_sess:    session to flag
2553  */
2554 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2555 {
2556         struct se_cmd *se_cmd;
2557         unsigned long flags;
2558
2559         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2560         if (se_sess->sess_tearing_down) {
2561                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2562                 return;
2563         }
2564         se_sess->sess_tearing_down = 1;
2565         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2566
2567         list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2568                 se_cmd->cmd_wait_set = 1;
2569
2570         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2571 }
2572 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2573
2574 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2575  * @se_sess:    session to wait for active I/O
2576  */
2577 void target_wait_for_sess_cmds(struct se_session *se_sess)
2578 {
2579         struct se_cmd *se_cmd, *tmp_cmd;
2580         unsigned long flags;
2581
2582         list_for_each_entry_safe(se_cmd, tmp_cmd,
2583                                 &se_sess->sess_wait_list, se_cmd_list) {
2584                 list_del(&se_cmd->se_cmd_list);
2585
2586                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2587                         " %d\n", se_cmd, se_cmd->t_state,
2588                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2589
2590                 wait_for_completion(&se_cmd->cmd_wait_comp);
2591                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2592                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2593                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2594
2595                 se_cmd->se_tfo->release_cmd(se_cmd);
2596         }
2597
2598         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2599         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2600         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2601
2602 }
2603 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2604
2605 void transport_clear_lun_ref(struct se_lun *lun)
2606 {
2607         percpu_ref_kill(&lun->lun_ref);
2608         wait_for_completion(&lun->lun_ref_comp);
2609 }
2610
2611 /**
2612  * transport_wait_for_tasks - wait for completion to occur
2613  * @cmd:        command to wait
2614  *
2615  * Called from frontend fabric context to wait for storage engine
2616  * to pause and/or release frontend generated struct se_cmd.
2617  */
2618 bool transport_wait_for_tasks(struct se_cmd *cmd)
2619 {
2620         unsigned long flags;
2621
2622         spin_lock_irqsave(&cmd->t_state_lock, flags);
2623         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2624             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2625                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2626                 return false;
2627         }
2628
2629         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2630             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2631                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2632                 return false;
2633         }
2634
2635         if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2636                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2637                 return false;
2638         }
2639
2640         cmd->transport_state |= CMD_T_STOP;
2641
2642         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d, t_state: %d, CMD_T_STOP\n",
2643                 cmd, cmd->tag, cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2644
2645         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2646
2647         wait_for_completion(&cmd->t_transport_stop_comp);
2648
2649         spin_lock_irqsave(&cmd->t_state_lock, flags);
2650         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2651
2652         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->t_transport_stop_comp) for ITT: 0x%08llx\n",
2653                 cmd->tag);
2654
2655         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2656
2657         return true;
2658 }
2659 EXPORT_SYMBOL(transport_wait_for_tasks);
2660
2661 struct sense_info {
2662         u8 key;
2663         u8 asc;
2664         u8 ascq;
2665         bool add_sector_info;
2666 };
2667
2668 static const struct sense_info sense_info_table[] = {
2669         [TCM_NO_SENSE] = {
2670                 .key = NOT_READY
2671         },
2672         [TCM_NON_EXISTENT_LUN] = {
2673                 .key = ILLEGAL_REQUEST,
2674                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2675         },
2676         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
2677                 .key = ILLEGAL_REQUEST,
2678                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2679         },
2680         [TCM_SECTOR_COUNT_TOO_MANY] = {
2681                 .key = ILLEGAL_REQUEST,
2682                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2683         },
2684         [TCM_UNKNOWN_MODE_PAGE] = {
2685                 .key = ILLEGAL_REQUEST,
2686                 .asc = 0x24, /* INVALID FIELD IN CDB */
2687         },
2688         [TCM_CHECK_CONDITION_ABORT_CMD] = {
2689                 .key = ABORTED_COMMAND,
2690                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2691                 .ascq = 0x03,
2692         },
2693         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
2694                 .key = ABORTED_COMMAND,
2695                 .asc = 0x0c, /* WRITE ERROR */
2696                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2697         },
2698         [TCM_INVALID_CDB_FIELD] = {
2699                 .key = ILLEGAL_REQUEST,
2700                 .asc = 0x24, /* INVALID FIELD IN CDB */
2701         },
2702         [TCM_INVALID_PARAMETER_LIST] = {
2703                 .key = ILLEGAL_REQUEST,
2704                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2705         },
2706         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2707                 .key = ILLEGAL_REQUEST,
2708                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2709         },
2710         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2711                 .key = ILLEGAL_REQUEST,
2712                 .asc = 0x0c, /* WRITE ERROR */
2713                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2714         },
2715         [TCM_SERVICE_CRC_ERROR] = {
2716                 .key = ABORTED_COMMAND,
2717                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2718                 .ascq = 0x05, /* N/A */
2719         },
2720         [TCM_SNACK_REJECTED] = {
2721                 .key = ABORTED_COMMAND,
2722                 .asc = 0x11, /* READ ERROR */
2723                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2724         },
2725         [TCM_WRITE_PROTECTED] = {
2726                 .key = DATA_PROTECT,
2727                 .asc = 0x27, /* WRITE PROTECTED */
2728         },
2729         [TCM_ADDRESS_OUT_OF_RANGE] = {
2730                 .key = ILLEGAL_REQUEST,
2731                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2732         },
2733         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2734                 .key = UNIT_ATTENTION,
2735         },
2736         [TCM_CHECK_CONDITION_NOT_READY] = {
2737                 .key = NOT_READY,
2738         },
2739         [TCM_MISCOMPARE_VERIFY] = {
2740                 .key = MISCOMPARE,
2741                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2742                 .ascq = 0x00,
2743         },
2744         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2745                 .key = ABORTED_COMMAND,
2746                 .asc = 0x10,
2747                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2748                 .add_sector_info = true,
2749         },
2750         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2751                 .key = ABORTED_COMMAND,
2752                 .asc = 0x10,
2753                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2754                 .add_sector_info = true,
2755         },
2756         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2757                 .key = ABORTED_COMMAND,
2758                 .asc = 0x10,
2759                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2760                 .add_sector_info = true,
2761         },
2762         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2763                 /*
2764                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2765                  * Solaris initiators.  Returning NOT READY instead means the
2766                  * operations will be retried a finite number of times and we
2767                  * can survive intermittent errors.
2768                  */
2769                 .key = NOT_READY,
2770                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2771         },
2772 };
2773
2774 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2775 {
2776         const struct sense_info *si;
2777         u8 *buffer = cmd->sense_buffer;
2778         int r = (__force int)reason;
2779         u8 asc, ascq;
2780         bool desc_format = target_sense_desc_format(cmd->se_dev);
2781
2782         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2783                 si = &sense_info_table[r];
2784         else
2785                 si = &sense_info_table[(__force int)
2786                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2787
2788         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2789                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2790                 WARN_ON_ONCE(asc == 0);
2791         } else if (si->asc == 0) {
2792                 WARN_ON_ONCE(cmd->scsi_asc == 0);
2793                 asc = cmd->scsi_asc;
2794                 ascq = cmd->scsi_ascq;
2795         } else {
2796                 asc = si->asc;
2797                 ascq = si->ascq;
2798         }
2799
2800         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2801         if (si->add_sector_info)
2802                 return scsi_set_sense_information(buffer,
2803                                                   cmd->scsi_sense_length,
2804                                                   cmd->bad_sector);
2805
2806         return 0;
2807 }
2808
2809 int
2810 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2811                 sense_reason_t reason, int from_transport)
2812 {
2813         unsigned long flags;
2814
2815         spin_lock_irqsave(&cmd->t_state_lock, flags);
2816         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2817                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2818                 return 0;
2819         }
2820         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2821         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2822
2823         if (!from_transport) {
2824                 int rc;
2825
2826                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2827                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2828                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2829                 rc = translate_sense_reason(cmd, reason);
2830                 if (rc)
2831                         return rc;
2832         }
2833
2834         trace_target_cmd_complete(cmd);
2835         return cmd->se_tfo->queue_status(cmd);
2836 }
2837 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2838
2839 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2840 {
2841         if (!(cmd->transport_state & CMD_T_ABORTED))
2842                 return 0;
2843
2844         /*
2845          * If cmd has been aborted but either no status is to be sent or it has
2846          * already been sent, just return
2847          */
2848         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
2849                 return 1;
2850
2851         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08llx\n",
2852                  cmd->t_task_cdb[0], cmd->tag);
2853
2854         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2855         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2856         trace_target_cmd_complete(cmd);
2857         cmd->se_tfo->queue_status(cmd);
2858
2859         return 1;
2860 }
2861 EXPORT_SYMBOL(transport_check_aborted_status);
2862
2863 void transport_send_task_abort(struct se_cmd *cmd)
2864 {
2865         unsigned long flags;
2866
2867         spin_lock_irqsave(&cmd->t_state_lock, flags);
2868         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
2869                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2870                 return;
2871         }
2872         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2873
2874         /*
2875          * If there are still expected incoming fabric WRITEs, we wait
2876          * until until they have completed before sending a TASK_ABORTED
2877          * response.  This response with TASK_ABORTED status will be
2878          * queued back to fabric module by transport_check_aborted_status().
2879          */
2880         if (cmd->data_direction == DMA_TO_DEVICE) {
2881                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2882                         cmd->transport_state |= CMD_T_ABORTED;
2883                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
2884                         return;
2885                 }
2886         }
2887         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2888
2889         transport_lun_remove_cmd(cmd);
2890
2891         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
2892                  cmd->t_task_cdb[0], cmd->tag);
2893
2894         trace_target_cmd_complete(cmd);
2895         cmd->se_tfo->queue_status(cmd);
2896 }
2897
2898 static void target_tmr_work(struct work_struct *work)
2899 {
2900         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2901         struct se_device *dev = cmd->se_dev;
2902         struct se_tmr_req *tmr = cmd->se_tmr_req;
2903         int ret;
2904
2905         switch (tmr->function) {
2906         case TMR_ABORT_TASK:
2907                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
2908                 break;
2909         case TMR_ABORT_TASK_SET:
2910         case TMR_CLEAR_ACA:
2911         case TMR_CLEAR_TASK_SET:
2912                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2913                 break;
2914         case TMR_LUN_RESET:
2915                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2916                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2917                                          TMR_FUNCTION_REJECTED;
2918                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
2919                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
2920                                                cmd->orig_fe_lun, 0x29,
2921                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
2922                 }
2923                 break;
2924         case TMR_TARGET_WARM_RESET:
2925                 tmr->response = TMR_FUNCTION_REJECTED;
2926                 break;
2927         case TMR_TARGET_COLD_RESET:
2928                 tmr->response = TMR_FUNCTION_REJECTED;
2929                 break;
2930         default:
2931                 pr_err("Uknown TMR function: 0x%02x.\n",
2932                                 tmr->function);
2933                 tmr->response = TMR_FUNCTION_REJECTED;
2934                 break;
2935         }
2936
2937         cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2938         cmd->se_tfo->queue_tm_rsp(cmd);
2939
2940         transport_cmd_check_stop_to_fabric(cmd);
2941 }
2942
2943 int transport_generic_handle_tmr(
2944         struct se_cmd *cmd)
2945 {
2946         unsigned long flags;
2947
2948         spin_lock_irqsave(&cmd->t_state_lock, flags);
2949         cmd->transport_state |= CMD_T_ACTIVE;
2950         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2951
2952         INIT_WORK(&cmd->work, target_tmr_work);
2953         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2954         return 0;
2955 }
2956 EXPORT_SYMBOL(transport_generic_handle_tmr);
2957
2958 bool
2959 target_check_wce(struct se_device *dev)
2960 {
2961         bool wce = false;
2962
2963         if (dev->transport->get_write_cache)
2964                 wce = dev->transport->get_write_cache(dev);
2965         else if (dev->dev_attrib.emulate_write_cache > 0)
2966                 wce = true;
2967
2968         return wce;
2969 }
2970
2971 bool
2972 target_check_fua(struct se_device *dev)
2973 {
2974         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
2975 }