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
 345                 spin_lock_irq(&se_nacl->nacl_sess_lock);
 346                 /*
 347                  * The se_nacl->nacl_sess pointer will be set to the
 348                  * last active I_T Nexus for each struct se_node_acl.
 349                  */
 350                 se_nacl->nacl_sess = se_sess;
 351
 352                 list_add_tail(&se_sess->sess_acl_list,
 353                               &se_nacl->acl_sess_list);
 354                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
 355         }
 356         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 357
 358         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 359                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 360 }
 361 EXPORT_SYMBOL(__transport_register_session);
 362
 363 void transport_register_session(
 364         struct se_portal_group *se_tpg,
 365         struct se_node_acl *se_nacl,
 366         struct se_session *se_sess,
 367         void *fabric_sess_ptr)
 368 {
 369         unsigned long flags;
 370
 371         spin_lock_irqsave(&se_tpg->session_lock, flags);
 372         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 373         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 374 }
 375 EXPORT_SYMBOL(transport_register_session);
 376
 377 static void target_release_session(struct kref *kref)
 378 {
 379         struct se_session *se_sess = container_of(kref,
 380                         struct se_session, sess_kref);
 381         struct se_portal_group *se_tpg = se_sess->se_tpg;
 382
 383         se_tpg->se_tpg_tfo->close_session(se_sess);
 384 }
 385
 386 int target_get_session(struct se_session *se_sess)
 387 {
 388         return kref_get_unless_zero(&se_sess->sess_kref);
 389 }
 390 EXPORT_SYMBOL(target_get_session);
 391
 392 void target_put_session(struct se_session *se_sess)
 393 {
 394         kref_put(&se_sess->sess_kref, target_release_session);
 395 }
 396 EXPORT_SYMBOL(target_put_session);
 397
 398 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 399 {
 400         struct se_session *se_sess;
 401         ssize_t len = 0;
 402
 403         spin_lock_bh(&se_tpg->session_lock);
 404         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 405                 if (!se_sess->se_node_acl)
 406                         continue;
 407                 if (!se_sess->se_node_acl->dynamic_node_acl)
 408                         continue;
 409                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 410                         break;
 411
 412                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 413                                 se_sess->se_node_acl->initiatorname);
 414                 len += 1; /* Include NULL terminator */
 415         }
 416         spin_unlock_bh(&se_tpg->session_lock);
 417
 418         return len;
 419 }
 420 EXPORT_SYMBOL(target_show_dynamic_sessions);
 421
 422 static void target_complete_nacl(struct kref *kref)
 423 {
 424         struct se_node_acl *nacl = container_of(kref,
 425                                 struct se_node_acl, acl_kref);
 426
 427         complete(&nacl->acl_free_comp);
 428 }
 429
 430 void target_put_nacl(struct se_node_acl *nacl)
 431 {
 432         kref_put(&nacl->acl_kref, target_complete_nacl);
 433 }
 434 EXPORT_SYMBOL(target_put_nacl);
 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         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 468         /*
 469          * Drop the se_node_acl->nacl_kref obtained from within
 470          * core_tpg_get_initiator_node_acl().
 471          */
 472         if (se_nacl) {
 473                 se_sess->se_node_acl = NULL;
 474                 target_put_nacl(se_nacl);
 475         }
 476         if (se_sess->sess_cmd_map) {
 477                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 478                 kvfree(se_sess->sess_cmd_map);
 479         }
 480         kmem_cache_free(se_sess_cache, se_sess);
 481 }
 482 EXPORT_SYMBOL(transport_free_session);
 483
 484 void transport_deregister_session(struct se_session *se_sess)
 485 {
 486         struct se_portal_group *se_tpg = se_sess->se_tpg;
 487         const struct target_core_fabric_ops *se_tfo;
 488         struct se_node_acl *se_nacl;
 489         unsigned long flags;
 490         bool drop_nacl = false;
 491
 492         if (!se_tpg) {
 493                 transport_free_session(se_sess);
 494                 return;
 495         }
 496         se_tfo = se_tpg->se_tpg_tfo;
 497
 498         spin_lock_irqsave(&se_tpg->session_lock, flags);
 499         list_del(&se_sess->sess_list);
 500         se_sess->se_tpg = NULL;
 501         se_sess->fabric_sess_ptr = NULL;
 502         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 503
 504         /*
 505          * Determine if we need to do extra work for this initiator node's
 506          * struct se_node_acl if it had been previously dynamically generated.
 507          */
 508         se_nacl = se_sess->se_node_acl;
 509
 510         mutex_lock(&se_tpg->acl_node_mutex);
 511         if (se_nacl && se_nacl->dynamic_node_acl) {
 512                 if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 513                         list_del(&se_nacl->acl_list);
 514                         drop_nacl = true;
 515                 }
 516         }
 517         mutex_unlock(&se_tpg->acl_node_mutex);
 518
 519         if (drop_nacl) {
 520                 core_tpg_wait_for_nacl_pr_ref(se_nacl);
 521                 core_free_device_list_for_node(se_nacl, se_tpg);
 522                 se_sess->se_node_acl = NULL;
 523                 kfree(se_nacl);
 524         }
 525         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 526                 se_tpg->se_tpg_tfo->get_fabric_name());
 527         /*
 528          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 529          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 530          * removal context from within transport_free_session() code.
 531          */
 532
 533         transport_free_session(se_sess);
 534 }
 535 EXPORT_SYMBOL(transport_deregister_session);
 536
 537 static void target_remove_from_state_list(struct se_cmd *cmd)
 538 {
 539         struct se_device *dev = cmd->se_dev;
 540         unsigned long flags;
 541
 542         if (!dev)
 543                 return;
 544
 545         if (cmd->transport_state & CMD_T_BUSY)
 546                 return;
 547
 548         spin_lock_irqsave(&dev->execute_task_lock, flags);
 549         if (cmd->state_active) {
 550                 list_del(&cmd->state_list);
 551                 cmd->state_active = false;
 552         }
 553         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 554 }
 555
 556 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 557                                     bool write_pending)
 558 {
 559         unsigned long flags;
 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         spin_lock_irqsave(&cmd->t_state_lock, flags);
 571         if (write_pending)
 572                 cmd->t_state = TRANSPORT_WRITE_PENDING;
 573
 574         /*
 575          * Determine if frontend context caller is requesting the stopping of
 576          * this command for frontend exceptions.
 577          */
 578         if (cmd->transport_state & CMD_T_STOP) {
 579                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 580                         __func__, __LINE__, cmd->tag);
 581
 582                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 583
 584                 complete_all(&cmd->t_transport_stop_comp);
 585                 return 1;
 586         }
 587
 588         cmd->transport_state &= ~CMD_T_ACTIVE;
 589         if (remove_from_lists) {
 590                 /*
 591                  * Some fabric modules like tcm_loop can release
 592                  * their internally allocated I/O reference now and
 593                  * struct se_cmd now.
 594                  *
 595                  * Fabric modules are expected to return '1' here if the
 596                  * se_cmd being passed is released at this point,
 597                  * or zero if not being released.
 598                  */
 599                 if (cmd->se_tfo->check_stop_free != NULL) {
 600                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 601                         return cmd->se_tfo->check_stop_free(cmd);
 602                 }
 603         }
 604
 605         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 606         return 0;
 607 }
 608
 609 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 610 {
 611         return transport_cmd_check_stop(cmd, true, false);
 612 }
 613
 614 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 615 {
 616         struct se_lun *lun = cmd->se_lun;
 617
 618         if (!lun)
 619                 return;
 620
 621         if (cmpxchg(&cmd->lun_ref_active, true, false))
 622                 percpu_ref_put(&lun->lun_ref);
 623 }
 624
 625 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 626 {
 627         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 628
 629         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 630                 transport_lun_remove_cmd(cmd);
 631         /*
 632          * Allow the fabric driver to unmap any resources before
 633          * releasing the descriptor via TFO->release_cmd()
 634          */
 635         if (remove)
 636                 cmd->se_tfo->aborted_task(cmd);
 637
 638         if (transport_cmd_check_stop_to_fabric(cmd))
 639                 return;
 640         if (remove && ack_kref)
 641                 transport_put_cmd(cmd);
 642 }
 643
 644 static void target_complete_failure_work(struct work_struct *work)
 645 {
 646         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 647
 648         transport_generic_request_failure(cmd,
 649                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 650 }
 651
 652 /*
 653  * Used when asking transport to copy Sense Data from the underlying
 654  * Linux/SCSI struct scsi_cmnd
 655  */
 656 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 657 {
 658         struct se_device *dev = cmd->se_dev;
 659
 660         WARN_ON(!cmd->se_lun);
 661
 662         if (!dev)
 663                 return NULL;
 664
 665         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 666                 return NULL;
 667
 668         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 669
 670         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 671                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 672         return cmd->sense_buffer;
 673 }
 674
 675 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 676 {
 677         struct se_device *dev = cmd->se_dev;
 678         int success = scsi_status == GOOD;
 679         unsigned long flags;
 680
 681         cmd->scsi_status = scsi_status;
 682
 683
 684         spin_lock_irqsave(&cmd->t_state_lock, flags);
 685         cmd->transport_state &= ~CMD_T_BUSY;
 686
 687         if (dev && dev->transport->transport_complete) {
 688                 dev->transport->transport_complete(cmd,
 689                                 cmd->t_data_sg,
 690                                 transport_get_sense_buffer(cmd));
 691                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 692                         success = 1;
 693         }
 694
 695         /*
 696          * See if we are waiting to complete for an exception condition.
 697          */
 698         if (cmd->transport_state & CMD_T_REQUEST_STOP) {
 699                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 700                 complete(&cmd->task_stop_comp);
 701                 return;
 702         }
 703
 704         /*
 705          * Check for case where an explicit ABORT_TASK has been received
 706          * and transport_wait_for_tasks() will be waiting for completion..
 707          */
 708         if (cmd->transport_state & CMD_T_ABORTED ||
 709             cmd->transport_state & CMD_T_STOP) {
 710                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 711                 complete_all(&cmd->t_transport_stop_comp);
 712                 return;
 713         } else if (!success) {
 714                 INIT_WORK(&cmd->work, target_complete_failure_work);
 715         } else {
 716                 INIT_WORK(&cmd->work, target_complete_ok_work);
 717         }
 718
 719         cmd->t_state = TRANSPORT_COMPLETE;
 720         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 721         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 722
 723         if (cmd->cpuid == -1)
 724                 queue_work(target_completion_wq, &cmd->work);
 725         else
 726                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 727 }
 728 EXPORT_SYMBOL(target_complete_cmd);
 729
 730 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 731 {
 732         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 733                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 734                         cmd->residual_count += cmd->data_length - length;
 735                 } else {
 736                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 737                         cmd->residual_count = cmd->data_length - length;
 738                 }
 739
 740                 cmd->data_length = length;
 741         }
 742
 743         target_complete_cmd(cmd, scsi_status);
 744 }
 745 EXPORT_SYMBOL(target_complete_cmd_with_length);
 746
 747 static void target_add_to_state_list(struct se_cmd *cmd)
 748 {
 749         struct se_device *dev = cmd->se_dev;
 750         unsigned long flags;
 751
 752         spin_lock_irqsave(&dev->execute_task_lock, flags);
 753         if (!cmd->state_active) {
 754                 list_add_tail(&cmd->state_list, &dev->state_list);
 755                 cmd->state_active = true;
 756         }
 757         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 758 }
 759
 760 /*
 761  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 762  */
 763 static void transport_write_pending_qf(struct se_cmd *cmd);
 764 static void transport_complete_qf(struct se_cmd *cmd);
 765
 766 void target_qf_do_work(struct work_struct *work)
 767 {
 768         struct se_device *dev = container_of(work, struct se_device,
 769                                         qf_work_queue);
 770         LIST_HEAD(qf_cmd_list);
 771         struct se_cmd *cmd, *cmd_tmp;
 772
 773         spin_lock_irq(&dev->qf_cmd_lock);
 774         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 775         spin_unlock_irq(&dev->qf_cmd_lock);
 776
 777         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 778                 list_del(&cmd->se_qf_node);
 779                 atomic_dec_mb(&dev->dev_qf_count);
 780
 781                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 782                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 783                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 784                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 785                         : "UNKNOWN");
 786
 787                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 788                         transport_write_pending_qf(cmd);
 789                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 790                         transport_complete_qf(cmd);
 791         }
 792 }
 793
 794 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 795 {
 796         switch (cmd->data_direction) {
 797         case DMA_NONE:
 798                 return "NONE";
 799         case DMA_FROM_DEVICE:
 800                 return "READ";
 801         case DMA_TO_DEVICE:
 802                 return "WRITE";
 803         case DMA_BIDIRECTIONAL:
 804                 return "BIDI";
 805         default:
 806                 break;
 807         }
 808
 809         return "UNKNOWN";
 810 }
 811
 812 void transport_dump_dev_state(
 813         struct se_device *dev,
 814         char *b,
 815         int *bl)
 816 {
 817         *bl += sprintf(b + *bl, "Status: ");
 818         if (dev->export_count)
 819                 *bl += sprintf(b + *bl, "ACTIVATED");
 820         else
 821                 *bl += sprintf(b + *bl, "DEACTIVATED");
 822
 823         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 824         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 825                 dev->dev_attrib.block_size,
 826                 dev->dev_attrib.hw_max_sectors);
 827         *bl += sprintf(b + *bl, "        ");
 828 }
 829
 830 void transport_dump_vpd_proto_id(
 831         struct t10_vpd *vpd,
 832         unsigned char *p_buf,
 833         int p_buf_len)
 834 {
 835         unsigned char buf[VPD_TMP_BUF_SIZE];
 836         int len;
 837
 838         memset(buf, 0, VPD_TMP_BUF_SIZE);
 839         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 840
 841         switch (vpd->protocol_identifier) {
 842         case 0x00:
 843                 sprintf(buf+len, "Fibre Channel\n");
 844                 break;
 845         case 0x10:
 846                 sprintf(buf+len, "Parallel SCSI\n");
 847                 break;
 848         case 0x20:
 849                 sprintf(buf+len, "SSA\n");
 850                 break;
 851         case 0x30:
 852                 sprintf(buf+len, "IEEE 1394\n");
 853                 break;
 854         case 0x40:
 855                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 856                                 " Protocol\n");
 857                 break;
 858         case 0x50:
 859                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 860                 break;
 861         case 0x60:
 862                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 863                 break;
 864         case 0x70:
 865                 sprintf(buf+len, "Automation/Drive Interface Transport"
 866                                 " Protocol\n");
 867                 break;
 868         case 0x80:
 869                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 870                 break;
 871         default:
 872                 sprintf(buf+len, "Unknown 0x%02x\n",
 873                                 vpd->protocol_identifier);
 874                 break;
 875         }
 876
 877         if (p_buf)
 878                 strncpy(p_buf, buf, p_buf_len);
 879         else
 880                 pr_debug("%s", buf);
 881 }
 882
 883 void
 884 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 885 {
 886         /*
 887          * Check if the Protocol Identifier Valid (PIV) bit is set..
 888          *
 889          * from spc3r23.pdf section 7.5.1
 890          */
 891          if (page_83[1] & 0x80) {
 892                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 893                 vpd->protocol_identifier_set = 1;
 894                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 895         }
 896 }
 897 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 898
 899 int transport_dump_vpd_assoc(
 900         struct t10_vpd *vpd,
 901         unsigned char *p_buf,
 902         int p_buf_len)
 903 {
 904         unsigned char buf[VPD_TMP_BUF_SIZE];
 905         int ret = 0;
 906         int len;
 907
 908         memset(buf, 0, VPD_TMP_BUF_SIZE);
 909         len = sprintf(buf, "T10 VPD Identifier Association: ");
 910
 911         switch (vpd->association) {
 912         case 0x00:
 913                 sprintf(buf+len, "addressed logical unit\n");
 914                 break;
 915         case 0x10:
 916                 sprintf(buf+len, "target port\n");
 917                 break;
 918         case 0x20:
 919                 sprintf(buf+len, "SCSI target device\n");
 920                 break;
 921         default:
 922                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 923                 ret = -EINVAL;
 924                 break;
 925         }
 926
 927         if (p_buf)
 928                 strncpy(p_buf, buf, p_buf_len);
 929         else
 930                 pr_debug("%s", buf);
 931
 932         return ret;
 933 }
 934
 935 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 936 {
 937         /*
 938          * The VPD identification association..
 939          *
 940          * from spc3r23.pdf Section 7.6.3.1 Table 297
 941          */
 942         vpd->association = (page_83[1] & 0x30);
 943         return transport_dump_vpd_assoc(vpd, NULL, 0);
 944 }
 945 EXPORT_SYMBOL(transport_set_vpd_assoc);
 946
 947 int transport_dump_vpd_ident_type(
 948         struct t10_vpd *vpd,
 949         unsigned char *p_buf,
 950         int p_buf_len)
 951 {
 952         unsigned char buf[VPD_TMP_BUF_SIZE];
 953         int ret = 0;
 954         int len;
 955
 956         memset(buf, 0, VPD_TMP_BUF_SIZE);
 957         len = sprintf(buf, "T10 VPD Identifier Type: ");
 958
 959         switch (vpd->device_identifier_type) {
 960         case 0x00:
 961                 sprintf(buf+len, "Vendor specific\n");
 962                 break;
 963         case 0x01:
 964                 sprintf(buf+len, "T10 Vendor ID based\n");
 965                 break;
 966         case 0x02:
 967                 sprintf(buf+len, "EUI-64 based\n");
 968                 break;
 969         case 0x03:
 970                 sprintf(buf+len, "NAA\n");
 971                 break;
 972         case 0x04:
 973                 sprintf(buf+len, "Relative target port identifier\n");
 974                 break;
 975         case 0x08:
 976                 sprintf(buf+len, "SCSI name string\n");
 977                 break;
 978         default:
 979                 sprintf(buf+len, "Unsupported: 0x%02x\n",
 980                                 vpd->device_identifier_type);
 981                 ret = -EINVAL;
 982                 break;
 983         }
 984
 985         if (p_buf) {
 986                 if (p_buf_len < strlen(buf)+1)
 987                         return -EINVAL;
 988                 strncpy(p_buf, buf, p_buf_len);
 989         } else {
 990                 pr_debug("%s", buf);
 991         }
 992
 993         return ret;
 994 }
 995
 996 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
 997 {
 998         /*
 999          * The VPD identifier type..
1000          *
1001          * from spc3r23.pdf Section 7.6.3.1 Table 298
1002          */
1003         vpd->device_identifier_type = (page_83[1] & 0x0f);
1004         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1005 }
1006 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1007
1008 int transport_dump_vpd_ident(
1009         struct t10_vpd *vpd,
1010         unsigned char *p_buf,
1011         int p_buf_len)
1012 {
1013         unsigned char buf[VPD_TMP_BUF_SIZE];
1014         int ret = 0;
1015
1016         memset(buf, 0, VPD_TMP_BUF_SIZE);
1017
1018         switch (vpd->device_identifier_code_set) {
1019         case 0x01: /* Binary */
1020                 snprintf(buf, sizeof(buf),
1021                         "T10 VPD Binary Device Identifier: %s\n",
1022                         &vpd->device_identifier[0]);
1023                 break;
1024         case 0x02: /* ASCII */
1025                 snprintf(buf, sizeof(buf),
1026                         "T10 VPD ASCII Device Identifier: %s\n",
1027                         &vpd->device_identifier[0]);
1028                 break;
1029         case 0x03: /* UTF-8 */
1030                 snprintf(buf, sizeof(buf),
1031                         "T10 VPD UTF-8 Device Identifier: %s\n",
1032                         &vpd->device_identifier[0]);
1033                 break;
1034         default:
1035                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1036                         " 0x%02x", vpd->device_identifier_code_set);
1037                 ret = -EINVAL;
1038                 break;
1039         }
1040
1041         if (p_buf)
1042                 strncpy(p_buf, buf, p_buf_len);
1043         else
1044                 pr_debug("%s", buf);
1045
1046         return ret;
1047 }
1048
1049 int
1050 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1051 {
1052         static const char hex_str[] = "0123456789abcdef";
1053         int j = 0, i = 4; /* offset to start of the identifier */
1054
1055         /*
1056          * The VPD Code Set (encoding)
1057          *
1058          * from spc3r23.pdf Section 7.6.3.1 Table 296
1059          */
1060         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1061         switch (vpd->device_identifier_code_set) {
1062         case 0x01: /* Binary */
1063                 vpd->device_identifier[j++] =
1064                                 hex_str[vpd->device_identifier_type];
1065                 while (i < (4 + page_83[3])) {
1066                         vpd->device_identifier[j++] =
1067                                 hex_str[(page_83[i] & 0xf0) >> 4];
1068                         vpd->device_identifier[j++] =
1069                                 hex_str[page_83[i] & 0x0f];
1070                         i++;
1071                 }
1072                 break;
1073         case 0x02: /* ASCII */
1074         case 0x03: /* UTF-8 */
1075                 while (i < (4 + page_83[3]))
1076                         vpd->device_identifier[j++] = page_83[i++];
1077                 break;
1078         default:
1079                 break;
1080         }
1081
1082         return transport_dump_vpd_ident(vpd, NULL, 0);
1083 }
1084 EXPORT_SYMBOL(transport_set_vpd_ident);
1085
1086 static sense_reason_t
1087 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1088                                unsigned int size)
1089 {
1090         u32 mtl;
1091
1092         if (!cmd->se_tfo->max_data_sg_nents)
1093                 return TCM_NO_SENSE;
1094         /*
1095          * Check if fabric enforced maximum SGL entries per I/O descriptor
1096          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1097          * residual_count and reduce original cmd->data_length to maximum
1098          * length based on single PAGE_SIZE entry scatter-lists.
1099          */
1100         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1101         if (cmd->data_length > mtl) {
1102                 /*
1103                  * If an existing CDB overflow is present, calculate new residual
1104                  * based on CDB size minus fabric maximum transfer length.
1105                  *
1106                  * If an existing CDB underflow is present, calculate new residual
1107                  * based on original cmd->data_length minus fabric maximum transfer
1108                  * length.
1109                  *
1110                  * Otherwise, set the underflow residual based on cmd->data_length
1111                  * minus fabric maximum transfer length.
1112                  */
1113                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1114                         cmd->residual_count = (size - mtl);
1115                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1116                         u32 orig_dl = size + cmd->residual_count;
1117                         cmd->residual_count = (orig_dl - mtl);
1118                 } else {
1119                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1120                         cmd->residual_count = (cmd->data_length - mtl);
1121                 }
1122                 cmd->data_length = mtl;
1123                 /*
1124                  * Reset sbc_check_prot() calculated protection payload
1125                  * length based upon the new smaller MTL.
1126                  */
1127                 if (cmd->prot_length) {
1128                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1129                         cmd->prot_length = dev->prot_length * sectors;
1130                 }
1131         }
1132         return TCM_NO_SENSE;
1133 }
1134
1135 sense_reason_t
1136 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1137 {
1138         struct se_device *dev = cmd->se_dev;
1139
1140         if (cmd->unknown_data_length) {
1141                 cmd->data_length = size;
1142         } else if (size != cmd->data_length) {
1143                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1144                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1145                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1146                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1147
1148                 if (cmd->data_direction == DMA_TO_DEVICE &&
1149                     cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1150                         pr_err("Rejecting underflow/overflow WRITE data\n");
1151                         return TCM_INVALID_CDB_FIELD;
1152                 }
1153                 /*
1154                  * Reject READ_* or WRITE_* with overflow/underflow for
1155                  * type SCF_SCSI_DATA_CDB.
1156                  */
1157                 if (dev->dev_attrib.block_size != 512)  {
1158                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1159                                 " CDB on non 512-byte sector setup subsystem"
1160                                 " plugin: %s\n", dev->transport->name);
1161                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1162                         return TCM_INVALID_CDB_FIELD;
1163                 }
1164                 /*
1165                  * For the overflow case keep the existing fabric provided
1166                  * ->data_length.  Otherwise for the underflow case, reset
1167                  * ->data_length to the smaller SCSI expected data transfer
1168                  * length.
1169                  */
1170                 if (size > cmd->data_length) {
1171                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1172                         cmd->residual_count = (size - cmd->data_length);
1173                 } else {
1174                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1175                         cmd->residual_count = (cmd->data_length - size);
1176                         cmd->data_length = size;
1177                 }
1178         }
1179
1180         return target_check_max_data_sg_nents(cmd, dev, size);
1181
1182 }
1183
1184 /*
1185  * Used by fabric modules containing a local struct se_cmd within their
1186  * fabric dependent per I/O descriptor.
1187  *
1188  * Preserves the value of @cmd->tag.
1189  */
1190 void transport_init_se_cmd(
1191         struct se_cmd *cmd,
1192         const struct target_core_fabric_ops *tfo,
1193         struct se_session *se_sess,
1194         u32 data_length,
1195         int data_direction,
1196         int task_attr,
1197         unsigned char *sense_buffer)
1198 {
1199         INIT_LIST_HEAD(&cmd->se_delayed_node);
1200         INIT_LIST_HEAD(&cmd->se_qf_node);
1201         INIT_LIST_HEAD(&cmd->se_cmd_list);
1202         INIT_LIST_HEAD(&cmd->state_list);
1203         init_completion(&cmd->t_transport_stop_comp);
1204         init_completion(&cmd->cmd_wait_comp);
1205         init_completion(&cmd->task_stop_comp);
1206         spin_lock_init(&cmd->t_state_lock);
1207         kref_init(&cmd->cmd_kref);
1208         cmd->transport_state = CMD_T_DEV_ACTIVE;
1209
1210         cmd->se_tfo = tfo;
1211         cmd->se_sess = se_sess;
1212         cmd->data_length = data_length;
1213         cmd->data_direction = data_direction;
1214         cmd->sam_task_attr = task_attr;
1215         cmd->sense_buffer = sense_buffer;
1216
1217         cmd->state_active = false;
1218 }
1219 EXPORT_SYMBOL(transport_init_se_cmd);
1220
1221 static sense_reason_t
1222 transport_check_alloc_task_attr(struct se_cmd *cmd)
1223 {
1224         struct se_device *dev = cmd->se_dev;
1225
1226         /*
1227          * Check if SAM Task Attribute emulation is enabled for this
1228          * struct se_device storage object
1229          */
1230         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1231                 return 0;
1232
1233         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1234                 pr_debug("SAM Task Attribute ACA"
1235                         " emulation is not supported\n");
1236                 return TCM_INVALID_CDB_FIELD;
1237         }
1238
1239         return 0;
1240 }
1241
1242 sense_reason_t
1243 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1244 {
1245         struct se_device *dev = cmd->se_dev;
1246         sense_reason_t ret;
1247
1248         /*
1249          * Ensure that the received CDB is less than the max (252 + 8) bytes
1250          * for VARIABLE_LENGTH_CMD
1251          */
1252         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1253                 pr_err("Received SCSI CDB with command_size: %d that"
1254                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1255                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1256                 return TCM_INVALID_CDB_FIELD;
1257         }
1258         /*
1259          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1260          * allocate the additional extended CDB buffer now..  Otherwise
1261          * setup the pointer from __t_task_cdb to t_task_cdb.
1262          */
1263         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1264                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1265                                                 GFP_KERNEL);
1266                 if (!cmd->t_task_cdb) {
1267                         pr_err("Unable to allocate cmd->t_task_cdb"
1268                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1269                                 scsi_command_size(cdb),
1270                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1271                         return TCM_OUT_OF_RESOURCES;
1272                 }
1273         } else
1274                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1275         /*
1276          * Copy the original CDB into cmd->
1277          */
1278         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1279
1280         trace_target_sequencer_start(cmd);
1281
1282         /*
1283          * Check for an existing UNIT ATTENTION condition
1284          */
1285         ret = target_scsi3_ua_check(cmd);
1286         if (ret)
1287                 return ret;
1288
1289         ret = target_alua_state_check(cmd);
1290         if (ret)
1291                 return ret;
1292
1293         ret = target_check_reservation(cmd);
1294         if (ret) {
1295                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1296                 return ret;
1297         }
1298
1299         ret = dev->transport->parse_cdb(cmd);
1300         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1301                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1302                                     cmd->se_tfo->get_fabric_name(),
1303                                     cmd->se_sess->se_node_acl->initiatorname,
1304                                     cmd->t_task_cdb[0]);
1305         if (ret)
1306                 return ret;
1307
1308         ret = transport_check_alloc_task_attr(cmd);
1309         if (ret)
1310                 return ret;
1311
1312         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1313         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1314         return 0;
1315 }
1316 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1317
1318 /*
1319  * Used by fabric module frontends to queue tasks directly.
1320  * May only be used from process context.
1321  */
1322 int transport_handle_cdb_direct(
1323         struct se_cmd *cmd)
1324 {
1325         sense_reason_t ret;
1326
1327         if (!cmd->se_lun) {
1328                 dump_stack();
1329                 pr_err("cmd->se_lun is NULL\n");
1330                 return -EINVAL;
1331         }
1332         if (in_interrupt()) {
1333                 dump_stack();
1334                 pr_err("transport_generic_handle_cdb cannot be called"
1335                                 " from interrupt context\n");
1336                 return -EINVAL;
1337         }
1338         /*
1339          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1340          * outstanding descriptors are handled correctly during shutdown via
1341          * transport_wait_for_tasks()
1342          *
1343          * Also, we don't take cmd->t_state_lock here as we only expect
1344          * this to be called for initial descriptor submission.
1345          */
1346         cmd->t_state = TRANSPORT_NEW_CMD;
1347         cmd->transport_state |= CMD_T_ACTIVE;
1348
1349         /*
1350          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1351          * so follow TRANSPORT_NEW_CMD processing thread context usage
1352          * and call transport_generic_request_failure() if necessary..
1353          */
1354         ret = transport_generic_new_cmd(cmd);
1355         if (ret)
1356                 transport_generic_request_failure(cmd, ret);
1357         return 0;
1358 }
1359 EXPORT_SYMBOL(transport_handle_cdb_direct);
1360
1361 sense_reason_t
1362 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1363                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1364 {
1365         if (!sgl || !sgl_count)
1366                 return 0;
1367
1368         /*
1369          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1370          * scatterlists already have been set to follow what the fabric
1371          * passes for the original expected data transfer length.
1372          */
1373         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1374                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1375                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1376                 return TCM_INVALID_CDB_FIELD;
1377         }
1378
1379         cmd->t_data_sg = sgl;
1380         cmd->t_data_nents = sgl_count;
1381         cmd->t_bidi_data_sg = sgl_bidi;
1382         cmd->t_bidi_data_nents = sgl_bidi_count;
1383
1384         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1385         return 0;
1386 }
1387
1388 /*
1389  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1390  *                       se_cmd + use pre-allocated SGL memory.
1391  *
1392  * @se_cmd: command descriptor to submit
1393  * @se_sess: associated se_sess for endpoint
1394  * @cdb: pointer to SCSI CDB
1395  * @sense: pointer to SCSI sense buffer
1396  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1397  * @data_length: fabric expected data transfer length
1398  * @task_addr: SAM task attribute
1399  * @data_dir: DMA data direction
1400  * @flags: flags for command submission from target_sc_flags_tables
1401  * @sgl: struct scatterlist memory for unidirectional mapping
1402  * @sgl_count: scatterlist count for unidirectional mapping
1403  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1404  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1405  * @sgl_prot: struct scatterlist memory protection information
1406  * @sgl_prot_count: scatterlist count for protection information
1407  *
1408  * Task tags are supported if the caller has set @se_cmd->tag.
1409  *
1410  * Returns non zero to signal active I/O shutdown failure.  All other
1411  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1412  * but still return zero here.
1413  *
1414  * This may only be called from process context, and also currently
1415  * assumes internal allocation of fabric payload buffer by target-core.
1416  */
1417 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1418                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1419                 u32 data_length, int task_attr, int data_dir, int flags,
1420                 struct scatterlist *sgl, u32 sgl_count,
1421                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1422                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1423 {
1424         struct se_portal_group *se_tpg;
1425         sense_reason_t rc;
1426         int ret;
1427
1428         se_tpg = se_sess->se_tpg;
1429         BUG_ON(!se_tpg);
1430         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1431         BUG_ON(in_interrupt());
1432         /*
1433          * Initialize se_cmd for target operation.  From this point
1434          * exceptions are handled by sending exception status via
1435          * target_core_fabric_ops->queue_status() callback
1436          */
1437         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1438                                 data_length, data_dir, task_attr, sense);
1439         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1440                 se_cmd->unknown_data_length = 1;
1441         /*
1442          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1443          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1444          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1445          * kref_put() to happen during fabric packet acknowledgement.
1446          */
1447         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1448         if (ret)
1449                 return ret;
1450         /*
1451          * Signal bidirectional data payloads to target-core
1452          */
1453         if (flags & TARGET_SCF_BIDI_OP)
1454                 se_cmd->se_cmd_flags |= SCF_BIDI;
1455         /*
1456          * Locate se_lun pointer and attach it to struct se_cmd
1457          */
1458         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1459         if (rc) {
1460                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1461                 target_put_sess_cmd(se_cmd);
1462                 return 0;
1463         }
1464
1465         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1466         if (rc != 0) {
1467                 transport_generic_request_failure(se_cmd, rc);
1468                 return 0;
1469         }
1470
1471         /*
1472          * Save pointers for SGLs containing protection information,
1473          * if present.
1474          */
1475         if (sgl_prot_count) {
1476                 se_cmd->t_prot_sg = sgl_prot;
1477                 se_cmd->t_prot_nents = sgl_prot_count;
1478                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1479         }
1480
1481         /*
1482          * When a non zero sgl_count has been passed perform SGL passthrough
1483          * mapping for pre-allocated fabric memory instead of having target
1484          * core perform an internal SGL allocation..
1485          */
1486         if (sgl_count != 0) {
1487                 BUG_ON(!sgl);
1488
1489                 /*
1490                  * A work-around for tcm_loop as some userspace code via
1491                  * scsi-generic do not memset their associated read buffers,
1492                  * so go ahead and do that here for type non-data CDBs.  Also
1493                  * note that this is currently guaranteed to be a single SGL
1494                  * for this case by target core in target_setup_cmd_from_cdb()
1495                  * -> transport_generic_cmd_sequencer().
1496                  */
1497                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1498                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1499                         unsigned char *buf = NULL;
1500
1501                         if (sgl)
1502                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1503
1504                         if (buf) {
1505                                 memset(buf, 0, sgl->length);
1506                                 kunmap(sg_page(sgl));
1507                         }
1508                 }
1509
1510                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1511                                 sgl_bidi, sgl_bidi_count);
1512                 if (rc != 0) {
1513                         transport_generic_request_failure(se_cmd, rc);
1514                         return 0;
1515                 }
1516         }
1517
1518         /*
1519          * Check if we need to delay processing because of ALUA
1520          * Active/NonOptimized primary access state..
1521          */
1522         core_alua_check_nonop_delay(se_cmd);
1523
1524         transport_handle_cdb_direct(se_cmd);
1525         return 0;
1526 }
1527 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1528
1529 /*
1530  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1531  *
1532  * @se_cmd: command descriptor to submit
1533  * @se_sess: associated se_sess for endpoint
1534  * @cdb: pointer to SCSI CDB
1535  * @sense: pointer to SCSI sense buffer
1536  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1537  * @data_length: fabric expected data transfer length
1538  * @task_addr: SAM task attribute
1539  * @data_dir: DMA data direction
1540  * @flags: flags for command submission from target_sc_flags_tables
1541  *
1542  * Task tags are supported if the caller has set @se_cmd->tag.
1543  *
1544  * Returns non zero to signal active I/O shutdown failure.  All other
1545  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1546  * but still return zero here.
1547  *
1548  * This may only be called from process context, and also currently
1549  * assumes internal allocation of fabric payload buffer by target-core.
1550  *
1551  * It also assumes interal target core SGL memory allocation.
1552  */
1553 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1554                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1555                 u32 data_length, int task_attr, int data_dir, int flags)
1556 {
1557         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1558                         unpacked_lun, data_length, task_attr, data_dir,
1559                         flags, NULL, 0, NULL, 0, NULL, 0);
1560 }
1561 EXPORT_SYMBOL(target_submit_cmd);
1562
1563 static void target_complete_tmr_failure(struct work_struct *work)
1564 {
1565         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1566
1567         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1568         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1569
1570         transport_cmd_check_stop_to_fabric(se_cmd);
1571 }
1572
1573 /**
1574  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1575  *                     for TMR CDBs
1576  *
1577  * @se_cmd: command descriptor to submit
1578  * @se_sess: associated se_sess for endpoint
1579  * @sense: pointer to SCSI sense buffer
1580  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1581  * @fabric_context: fabric context for TMR req
1582  * @tm_type: Type of TM request
1583  * @gfp: gfp type for caller
1584  * @tag: referenced task tag for TMR_ABORT_TASK
1585  * @flags: submit cmd flags
1586  *
1587  * Callable from all contexts.
1588  **/
1589
1590 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1591                 unsigned char *sense, u64 unpacked_lun,
1592                 void *fabric_tmr_ptr, unsigned char tm_type,
1593                 gfp_t gfp, u64 tag, int flags)
1594 {
1595         struct se_portal_group *se_tpg;
1596         int ret;
1597
1598         se_tpg = se_sess->se_tpg;
1599         BUG_ON(!se_tpg);
1600
1601         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1602                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1603         /*
1604          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1605          * allocation failure.
1606          */
1607         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1608         if (ret < 0)
1609                 return -ENOMEM;
1610
1611         if (tm_type == TMR_ABORT_TASK)
1612                 se_cmd->se_tmr_req->ref_task_tag = tag;
1613
1614         /* See target_submit_cmd for commentary */
1615         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1616         if (ret) {
1617                 core_tmr_release_req(se_cmd->se_tmr_req);
1618                 return ret;
1619         }
1620
1621         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1622         if (ret) {
1623                 /*
1624                  * For callback during failure handling, push this work off
1625                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1626                  */
1627                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1628                 schedule_work(&se_cmd->work);
1629                 return 0;
1630         }
1631         transport_generic_handle_tmr(se_cmd);
1632         return 0;
1633 }
1634 EXPORT_SYMBOL(target_submit_tmr);
1635
1636 /*
1637  * If the cmd is active, request it to be stopped and sleep until it
1638  * has completed.
1639  */
1640 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1641         __releases(&cmd->t_state_lock)
1642         __acquires(&cmd->t_state_lock)
1643 {
1644         bool was_active = false;
1645
1646         if (cmd->transport_state & CMD_T_BUSY) {
1647                 cmd->transport_state |= CMD_T_REQUEST_STOP;
1648                 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1649
1650                 pr_debug("cmd %p waiting to complete\n", cmd);
1651                 wait_for_completion(&cmd->task_stop_comp);
1652                 pr_debug("cmd %p stopped successfully\n", cmd);
1653
1654                 spin_lock_irqsave(&cmd->t_state_lock, *flags);
1655                 cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1656                 cmd->transport_state &= ~CMD_T_BUSY;
1657                 was_active = true;
1658         }
1659
1660         return was_active;
1661 }
1662
1663 /*
1664  * Handle SAM-esque emulation for generic transport request failures.
1665  */
1666 void transport_generic_request_failure(struct se_cmd *cmd,
1667                 sense_reason_t sense_reason)
1668 {
1669         int ret = 0, post_ret = 0;
1670
1671         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1672                 " CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1673         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1674                 cmd->se_tfo->get_cmd_state(cmd),
1675                 cmd->t_state, sense_reason);
1676         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1677                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1678                 (cmd->transport_state & CMD_T_STOP) != 0,
1679                 (cmd->transport_state & CMD_T_SENT) != 0);
1680
1681         /*
1682          * For SAM Task Attribute emulation for failed struct se_cmd
1683          */
1684         transport_complete_task_attr(cmd);
1685         /*
1686          * Handle special case for COMPARE_AND_WRITE failure, where the
1687          * callback is expected to drop the per device ->caw_sem.
1688          */
1689         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1690              cmd->transport_complete_callback)
1691                 cmd->transport_complete_callback(cmd, false, &post_ret);
1692
1693         switch (sense_reason) {
1694         case TCM_NON_EXISTENT_LUN:
1695         case TCM_UNSUPPORTED_SCSI_OPCODE:
1696         case TCM_INVALID_CDB_FIELD:
1697         case TCM_INVALID_PARAMETER_LIST:
1698         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1699         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1700         case TCM_UNKNOWN_MODE_PAGE:
1701         case TCM_WRITE_PROTECTED:
1702         case TCM_ADDRESS_OUT_OF_RANGE:
1703         case TCM_CHECK_CONDITION_ABORT_CMD:
1704         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1705         case TCM_CHECK_CONDITION_NOT_READY:
1706         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1707         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1708         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1709                 break;
1710         case TCM_OUT_OF_RESOURCES:
1711                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1712                 break;
1713         case TCM_RESERVATION_CONFLICT:
1714                 /*
1715                  * No SENSE Data payload for this case, set SCSI Status
1716                  * and queue the response to $FABRIC_MOD.
1717                  *
1718                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1719                  */
1720                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1721                 /*
1722                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1723                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1724                  * CONFLICT STATUS.
1725                  *
1726                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1727                  */
1728                 if (cmd->se_sess &&
1729                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1730                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1731                                                cmd->orig_fe_lun, 0x2C,
1732                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1733                 }
1734                 trace_target_cmd_complete(cmd);
1735                 ret = cmd->se_tfo->queue_status(cmd);
1736                 if (ret == -EAGAIN || ret == -ENOMEM)
1737                         goto queue_full;
1738                 goto check_stop;
1739         default:
1740                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1741                         cmd->t_task_cdb[0], sense_reason);
1742                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1743                 break;
1744         }
1745
1746         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1747         if (ret == -EAGAIN || ret == -ENOMEM)
1748                 goto queue_full;
1749
1750 check_stop:
1751         transport_lun_remove_cmd(cmd);
1752         transport_cmd_check_stop_to_fabric(cmd);
1753         return;
1754
1755 queue_full:
1756         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1757         transport_handle_queue_full(cmd, cmd->se_dev);
1758 }
1759 EXPORT_SYMBOL(transport_generic_request_failure);
1760
1761 void __target_execute_cmd(struct se_cmd *cmd)
1762 {
1763         sense_reason_t ret;
1764
1765         if (cmd->execute_cmd) {
1766                 ret = cmd->execute_cmd(cmd);
1767                 if (ret) {
1768                         spin_lock_irq(&cmd->t_state_lock);
1769                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1770                         spin_unlock_irq(&cmd->t_state_lock);
1771
1772                         transport_generic_request_failure(cmd, ret);
1773                 }
1774         }
1775 }
1776
1777 static int target_write_prot_action(struct se_cmd *cmd)
1778 {
1779         u32 sectors;
1780         /*
1781          * Perform WRITE_INSERT of PI using software emulation when backend
1782          * device has PI enabled, if the transport has not already generated
1783          * PI using hardware WRITE_INSERT offload.
1784          */
1785         switch (cmd->prot_op) {
1786         case TARGET_PROT_DOUT_INSERT:
1787                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1788                         sbc_dif_generate(cmd);
1789                 break;
1790         case TARGET_PROT_DOUT_STRIP:
1791                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1792                         break;
1793
1794                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1795                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1796                                              sectors, 0, cmd->t_prot_sg, 0);
1797                 if (unlikely(cmd->pi_err)) {
1798                         spin_lock_irq(&cmd->t_state_lock);
1799                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1800                         spin_unlock_irq(&cmd->t_state_lock);
1801                         transport_generic_request_failure(cmd, cmd->pi_err);
1802                         return -1;
1803                 }
1804                 break;
1805         default:
1806                 break;
1807         }
1808
1809         return 0;
1810 }
1811
1812 static bool target_handle_task_attr(struct se_cmd *cmd)
1813 {
1814         struct se_device *dev = cmd->se_dev;
1815
1816         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1817                 return false;
1818
1819         /*
1820          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1821          * to allow the passed struct se_cmd list of tasks to the front of the list.
1822          */
1823         switch (cmd->sam_task_attr) {
1824         case TCM_HEAD_TAG:
1825                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1826                          cmd->t_task_cdb[0]);
1827                 return false;
1828         case TCM_ORDERED_TAG:
1829                 atomic_inc_mb(&dev->dev_ordered_sync);
1830
1831                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1832                          cmd->t_task_cdb[0]);
1833
1834                 /*
1835                  * Execute an ORDERED command if no other older commands
1836                  * exist that need to be completed first.
1837                  */
1838                 if (!atomic_read(&dev->simple_cmds))
1839                         return false;
1840                 break;
1841         default:
1842                 /*
1843                  * For SIMPLE and UNTAGGED Task Attribute commands
1844                  */
1845                 atomic_inc_mb(&dev->simple_cmds);
1846                 break;
1847         }
1848
1849         if (atomic_read(&dev->dev_ordered_sync) == 0)
1850                 return false;
1851
1852         spin_lock(&dev->delayed_cmd_lock);
1853         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1854         spin_unlock(&dev->delayed_cmd_lock);
1855
1856         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1857                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1858         return true;
1859 }
1860
1861 void target_execute_cmd(struct se_cmd *cmd)
1862 {
1863         /*
1864          * If the received CDB has aleady been aborted stop processing it here.
1865          */
1866         if (transport_check_aborted_status(cmd, 1))
1867                 return;
1868
1869         /*
1870          * Determine if frontend context caller is requesting the stopping of
1871          * this command for frontend exceptions.
1872          */
1873         spin_lock_irq(&cmd->t_state_lock);
1874         if (cmd->transport_state & CMD_T_STOP) {
1875                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1876                         __func__, __LINE__, cmd->tag);
1877
1878                 spin_unlock_irq(&cmd->t_state_lock);
1879                 complete_all(&cmd->t_transport_stop_comp);
1880                 return;
1881         }
1882
1883         cmd->t_state = TRANSPORT_PROCESSING;
1884         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1885         spin_unlock_irq(&cmd->t_state_lock);
1886
1887         if (target_write_prot_action(cmd))
1888                 return;
1889
1890         if (target_handle_task_attr(cmd)) {
1891                 spin_lock_irq(&cmd->t_state_lock);
1892                 cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1893                 spin_unlock_irq(&cmd->t_state_lock);
1894                 return;
1895         }
1896
1897         __target_execute_cmd(cmd);
1898 }
1899 EXPORT_SYMBOL(target_execute_cmd);
1900
1901 /*
1902  * Process all commands up to the last received ORDERED task attribute which
1903  * requires another blocking boundary
1904  */
1905 static void target_restart_delayed_cmds(struct se_device *dev)
1906 {
1907         for (;;) {
1908                 struct se_cmd *cmd;
1909
1910                 spin_lock(&dev->delayed_cmd_lock);
1911                 if (list_empty(&dev->delayed_cmd_list)) {
1912                         spin_unlock(&dev->delayed_cmd_lock);
1913                         break;
1914                 }
1915
1916                 cmd = list_entry(dev->delayed_cmd_list.next,
1917                                  struct se_cmd, se_delayed_node);
1918                 list_del(&cmd->se_delayed_node);
1919                 spin_unlock(&dev->delayed_cmd_lock);
1920
1921                 __target_execute_cmd(cmd);
1922
1923                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1924                         break;
1925         }
1926 }
1927
1928 /*
1929  * Called from I/O completion to determine which dormant/delayed
1930  * and ordered cmds need to have their tasks added to the execution queue.
1931  */
1932 static void transport_complete_task_attr(struct se_cmd *cmd)
1933 {
1934         struct se_device *dev = cmd->se_dev;
1935
1936         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1937                 return;
1938
1939         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1940                 atomic_dec_mb(&dev->simple_cmds);
1941                 dev->dev_cur_ordered_id++;
1942                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for SIMPLE\n",
1943                          dev->dev_cur_ordered_id);
1944         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1945                 dev->dev_cur_ordered_id++;
1946                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1947                          dev->dev_cur_ordered_id);
1948         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1949                 atomic_dec_mb(&dev->dev_ordered_sync);
1950
1951                 dev->dev_cur_ordered_id++;
1952                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1953                          dev->dev_cur_ordered_id);
1954         }
1955
1956         target_restart_delayed_cmds(dev);
1957 }
1958
1959 static void transport_complete_qf(struct se_cmd *cmd)
1960 {
1961         int ret = 0;
1962
1963         transport_complete_task_attr(cmd);
1964
1965         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1966                 trace_target_cmd_complete(cmd);
1967                 ret = cmd->se_tfo->queue_status(cmd);
1968                 goto out;
1969         }
1970
1971         switch (cmd->data_direction) {
1972         case DMA_FROM_DEVICE:
1973                 trace_target_cmd_complete(cmd);
1974                 ret = cmd->se_tfo->queue_data_in(cmd);
1975                 break;
1976         case DMA_TO_DEVICE:
1977                 if (cmd->se_cmd_flags & SCF_BIDI) {
1978                         ret = cmd->se_tfo->queue_data_in(cmd);
1979                         break;
1980                 }
1981                 /* Fall through for DMA_TO_DEVICE */
1982         case DMA_NONE:
1983                 trace_target_cmd_complete(cmd);
1984                 ret = cmd->se_tfo->queue_status(cmd);
1985                 break;
1986         default:
1987                 break;
1988         }
1989
1990 out:
1991         if (ret < 0) {
1992                 transport_handle_queue_full(cmd, cmd->se_dev);
1993                 return;
1994         }
1995         transport_lun_remove_cmd(cmd);
1996         transport_cmd_check_stop_to_fabric(cmd);
1997 }
1998
1999 static void transport_handle_queue_full(
2000         struct se_cmd *cmd,
2001         struct se_device *dev)
2002 {
2003         spin_lock_irq(&dev->qf_cmd_lock);
2004         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2005         atomic_inc_mb(&dev->dev_qf_count);
2006         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2007
2008         schedule_work(&cmd->se_dev->qf_work_queue);
2009 }
2010
2011 static bool target_read_prot_action(struct se_cmd *cmd)
2012 {
2013         switch (cmd->prot_op) {
2014         case TARGET_PROT_DIN_STRIP:
2015                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2016                         u32 sectors = cmd->data_length >>
2017                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2018
2019                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2020                                                      sectors, 0, cmd->t_prot_sg,
2021                                                      0);
2022                         if (cmd->pi_err)
2023                                 return true;
2024                 }
2025                 break;
2026         case TARGET_PROT_DIN_INSERT:
2027                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2028                         break;
2029
2030                 sbc_dif_generate(cmd);
2031                 break;
2032         default:
2033                 break;
2034         }
2035
2036         return false;
2037 }
2038
2039 static void target_complete_ok_work(struct work_struct *work)
2040 {
2041         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2042         int ret;
2043
2044         /*
2045          * Check if we need to move delayed/dormant tasks from cmds on the
2046          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2047          * Attribute.
2048          */
2049         transport_complete_task_attr(cmd);
2050
2051         /*
2052          * Check to schedule QUEUE_FULL work, or execute an existing
2053          * cmd->transport_qf_callback()
2054          */
2055         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2056                 schedule_work(&cmd->se_dev->qf_work_queue);
2057
2058         /*
2059          * Check if we need to send a sense buffer from
2060          * the struct se_cmd in question.
2061          */
2062         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2063                 WARN_ON(!cmd->scsi_status);
2064                 ret = transport_send_check_condition_and_sense(
2065                                         cmd, 0, 1);
2066                 if (ret == -EAGAIN || ret == -ENOMEM)
2067                         goto queue_full;
2068
2069                 transport_lun_remove_cmd(cmd);
2070                 transport_cmd_check_stop_to_fabric(cmd);
2071                 return;
2072         }
2073         /*
2074          * Check for a callback, used by amongst other things
2075          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2076          */
2077         if (cmd->transport_complete_callback) {
2078                 sense_reason_t rc;
2079                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2080                 bool zero_dl = !(cmd->data_length);
2081                 int post_ret = 0;
2082
2083                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2084                 if (!rc && !post_ret) {
2085                         if (caw && zero_dl)
2086                                 goto queue_rsp;
2087
2088                         return;
2089                 } else if (rc) {
2090                         ret = transport_send_check_condition_and_sense(cmd,
2091                                                 rc, 0);
2092                         if (ret == -EAGAIN || ret == -ENOMEM)
2093                                 goto queue_full;
2094
2095                         transport_lun_remove_cmd(cmd);
2096                         transport_cmd_check_stop_to_fabric(cmd);
2097                         return;
2098                 }
2099         }
2100
2101 queue_rsp:
2102         switch (cmd->data_direction) {
2103         case DMA_FROM_DEVICE:
2104                 atomic_long_add(cmd->data_length,
2105                                 &cmd->se_lun->lun_stats.tx_data_octets);
2106                 /*
2107                  * Perform READ_STRIP of PI using software emulation when
2108                  * backend had PI enabled, if the transport will not be
2109                  * performing hardware READ_STRIP offload.
2110                  */
2111                 if (target_read_prot_action(cmd)) {
2112                         ret = transport_send_check_condition_and_sense(cmd,
2113                                                 cmd->pi_err, 0);
2114                         if (ret == -EAGAIN || ret == -ENOMEM)
2115                                 goto queue_full;
2116
2117                         transport_lun_remove_cmd(cmd);
2118                         transport_cmd_check_stop_to_fabric(cmd);
2119                         return;
2120                 }
2121
2122                 trace_target_cmd_complete(cmd);
2123                 ret = cmd->se_tfo->queue_data_in(cmd);
2124                 if (ret == -EAGAIN || ret == -ENOMEM)
2125                         goto queue_full;
2126                 break;
2127         case DMA_TO_DEVICE:
2128                 atomic_long_add(cmd->data_length,
2129                                 &cmd->se_lun->lun_stats.rx_data_octets);
2130                 /*
2131                  * Check if we need to send READ payload for BIDI-COMMAND
2132                  */
2133                 if (cmd->se_cmd_flags & SCF_BIDI) {
2134                         atomic_long_add(cmd->data_length,
2135                                         &cmd->se_lun->lun_stats.tx_data_octets);
2136                         ret = cmd->se_tfo->queue_data_in(cmd);
2137                         if (ret == -EAGAIN || ret == -ENOMEM)
2138                                 goto queue_full;
2139                         break;
2140                 }
2141                 /* Fall through for DMA_TO_DEVICE */
2142         case DMA_NONE:
2143                 trace_target_cmd_complete(cmd);
2144                 ret = cmd->se_tfo->queue_status(cmd);
2145                 if (ret == -EAGAIN || ret == -ENOMEM)
2146                         goto queue_full;
2147                 break;
2148         default:
2149                 break;
2150         }
2151
2152         transport_lun_remove_cmd(cmd);
2153         transport_cmd_check_stop_to_fabric(cmd);
2154         return;
2155
2156 queue_full:
2157         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2158                 " data_direction: %d\n", cmd, cmd->data_direction);
2159         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2160         transport_handle_queue_full(cmd, cmd->se_dev);
2161 }
2162
2163 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2164 {
2165         struct scatterlist *sg;
2166         int count;
2167
2168         for_each_sg(sgl, sg, nents, count)
2169                 __free_page(sg_page(sg));
2170
2171         kfree(sgl);
2172 }
2173
2174 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2175 {
2176         /*
2177          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2178          * emulation, and free + reset pointers if necessary..
2179          */
2180         if (!cmd->t_data_sg_orig)
2181                 return;
2182
2183         kfree(cmd->t_data_sg);
2184         cmd->t_data_sg = cmd->t_data_sg_orig;
2185         cmd->t_data_sg_orig = NULL;
2186         cmd->t_data_nents = cmd->t_data_nents_orig;
2187         cmd->t_data_nents_orig = 0;
2188 }
2189
2190 static inline void transport_free_pages(struct se_cmd *cmd)
2191 {
2192         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2193                 transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2194                 cmd->t_prot_sg = NULL;
2195                 cmd->t_prot_nents = 0;
2196         }
2197
2198         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2199                 /*
2200                  * Release special case READ buffer payload required for
2201                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2202                  */
2203                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2204                         transport_free_sgl(cmd->t_bidi_data_sg,
2205                                            cmd->t_bidi_data_nents);
2206                         cmd->t_bidi_data_sg = NULL;
2207                         cmd->t_bidi_data_nents = 0;
2208                 }
2209                 transport_reset_sgl_orig(cmd);
2210                 return;
2211         }
2212         transport_reset_sgl_orig(cmd);
2213
2214         transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2215         cmd->t_data_sg = NULL;
2216         cmd->t_data_nents = 0;
2217
2218         transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2219         cmd->t_bidi_data_sg = NULL;
2220         cmd->t_bidi_data_nents = 0;
2221 }
2222
2223 /**
2224  * transport_put_cmd - release a reference to a command
2225  * @cmd:       command to release
2226  *
2227  * This routine releases our reference to the command and frees it if possible.
2228  */
2229 static int transport_put_cmd(struct se_cmd *cmd)
2230 {
2231         BUG_ON(!cmd->se_tfo);
2232         /*
2233          * If this cmd has been setup with target_get_sess_cmd(), drop
2234          * the kref and call ->release_cmd() in kref callback.
2235          */
2236         return target_put_sess_cmd(cmd);
2237 }
2238
2239 void *transport_kmap_data_sg(struct se_cmd *cmd)
2240 {
2241         struct scatterlist *sg = cmd->t_data_sg;
2242         struct page **pages;
2243         int i;
2244
2245         /*
2246          * We need to take into account a possible offset here for fabrics like
2247          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2248          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2249          */
2250         if (!cmd->t_data_nents)
2251                 return NULL;
2252
2253         BUG_ON(!sg);
2254         if (cmd->t_data_nents == 1)
2255                 return kmap(sg_page(sg)) + sg->offset;
2256
2257         /* >1 page. use vmap */
2258         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2259         if (!pages)
2260                 return NULL;
2261
2262         /* convert sg[] to pages[] */
2263         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2264                 pages[i] = sg_page(sg);
2265         }
2266
2267         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2268         kfree(pages);
2269         if (!cmd->t_data_vmap)
2270                 return NULL;
2271
2272         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2273 }
2274 EXPORT_SYMBOL(transport_kmap_data_sg);
2275
2276 void transport_kunmap_data_sg(struct se_cmd *cmd)
2277 {
2278         if (!cmd->t_data_nents) {
2279                 return;
2280         } else if (cmd->t_data_nents == 1) {
2281                 kunmap(sg_page(cmd->t_data_sg));
2282                 return;
2283         }
2284
2285         vunmap(cmd->t_data_vmap);
2286         cmd->t_data_vmap = NULL;
2287 }
2288 EXPORT_SYMBOL(transport_kunmap_data_sg);
2289
2290 int
2291 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2292                  bool zero_page)
2293 {
2294         struct scatterlist *sg;
2295         struct page *page;
2296         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2297         unsigned int nent;
2298         int i = 0;
2299
2300         nent = DIV_ROUND_UP(length, PAGE_SIZE);
2301         sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2302         if (!sg)
2303                 return -ENOMEM;
2304
2305         sg_init_table(sg, nent);
2306
2307         while (length) {
2308                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2309                 page = alloc_page(GFP_KERNEL | zero_flag);
2310                 if (!page)
2311                         goto out;
2312
2313                 sg_set_page(&sg[i], page, page_len, 0);
2314                 length -= page_len;
2315                 i++;
2316         }
2317         *sgl = sg;
2318         *nents = nent;
2319         return 0;
2320
2321 out:
2322         while (i > 0) {
2323                 i--;
2324                 __free_page(sg_page(&sg[i]));
2325         }
2326         kfree(sg);
2327         return -ENOMEM;
2328 }
2329
2330 /*
2331  * Allocate any required resources to execute the command.  For writes we
2332  * might not have the payload yet, so notify the fabric via a call to
2333  * ->write_pending instead. Otherwise place it on the execution queue.
2334  */
2335 sense_reason_t
2336 transport_generic_new_cmd(struct se_cmd *cmd)
2337 {
2338         int ret = 0;
2339         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2340
2341         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2342             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2343                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2344                                        cmd->prot_length, true);
2345                 if (ret < 0)
2346                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2347         }
2348
2349         /*
2350          * Determine is the TCM fabric module has already allocated physical
2351          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2352          * beforehand.
2353          */
2354         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2355             cmd->data_length) {
2356
2357                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2358                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2359                         u32 bidi_length;
2360
2361                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2362                                 bidi_length = cmd->t_task_nolb *
2363                                               cmd->se_dev->dev_attrib.block_size;
2364                         else
2365                                 bidi_length = cmd->data_length;
2366
2367                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2368                                                &cmd->t_bidi_data_nents,
2369                                                bidi_length, zero_flag);
2370                         if (ret < 0)
2371                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2372                 }
2373
2374                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2375                                        cmd->data_length, zero_flag);
2376                 if (ret < 0)
2377                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2378         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2379                     cmd->data_length) {
2380                 /*
2381                  * Special case for COMPARE_AND_WRITE with fabrics
2382                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2383                  */
2384                 u32 caw_length = cmd->t_task_nolb *
2385                                  cmd->se_dev->dev_attrib.block_size;
2386
2387                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2388                                        &cmd->t_bidi_data_nents,
2389                                        caw_length, zero_flag);
2390                 if (ret < 0)
2391                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2392         }
2393         /*
2394          * If this command is not a write we can execute it right here,
2395          * for write buffers we need to notify the fabric driver first
2396          * and let it call back once the write buffers are ready.
2397          */
2398         target_add_to_state_list(cmd);
2399         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2400                 target_execute_cmd(cmd);
2401                 return 0;
2402         }
2403         transport_cmd_check_stop(cmd, false, true);
2404
2405         ret = cmd->se_tfo->write_pending(cmd);
2406         if (ret == -EAGAIN || ret == -ENOMEM)
2407                 goto queue_full;
2408
2409         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2410         WARN_ON(ret);
2411
2412         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2413
2414 queue_full:
2415         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2416         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2417         transport_handle_queue_full(cmd, cmd->se_dev);
2418         return 0;
2419 }
2420 EXPORT_SYMBOL(transport_generic_new_cmd);
2421
2422 static void transport_write_pending_qf(struct se_cmd *cmd)
2423 {
2424         int ret;
2425
2426         ret = cmd->se_tfo->write_pending(cmd);
2427         if (ret == -EAGAIN || ret == -ENOMEM) {
2428                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2429                          cmd);
2430                 transport_handle_queue_full(cmd, cmd->se_dev);
2431         }
2432 }
2433
2434 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2435 {
2436         int ret = 0;
2437
2438         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2439                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2440                         transport_wait_for_tasks(cmd);
2441
2442                 ret = transport_put_cmd(cmd);
2443         } else {
2444                 if (wait_for_tasks)
2445                         transport_wait_for_tasks(cmd);
2446                 /*
2447                  * Handle WRITE failure case where transport_generic_new_cmd()
2448                  * has already added se_cmd to state_list, but fabric has
2449                  * failed command before I/O submission.
2450                  */
2451                 if (cmd->state_active)
2452                         target_remove_from_state_list(cmd);
2453
2454                 if (cmd->se_lun)
2455                         transport_lun_remove_cmd(cmd);
2456
2457                 ret = transport_put_cmd(cmd);
2458         }
2459         return ret;
2460 }
2461 EXPORT_SYMBOL(transport_generic_free_cmd);
2462
2463 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2464  * @se_cmd:     command descriptor to add
2465  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2466  */
2467 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2468 {
2469         struct se_session *se_sess = se_cmd->se_sess;
2470         unsigned long flags;
2471         int ret = 0;
2472
2473         /*
2474          * Add a second kref if the fabric caller is expecting to handle
2475          * fabric acknowledgement that requires two target_put_sess_cmd()
2476          * invocations before se_cmd descriptor release.
2477          */
2478         if (ack_kref)
2479                 kref_get(&se_cmd->cmd_kref);
2480
2481         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2482         if (se_sess->sess_tearing_down) {
2483                 ret = -ESHUTDOWN;
2484                 goto out;
2485         }
2486         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2487 out:
2488         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2489
2490         if (ret && ack_kref)
2491                 target_put_sess_cmd(se_cmd);
2492
2493         return ret;
2494 }
2495 EXPORT_SYMBOL(target_get_sess_cmd);
2496
2497 static void target_free_cmd_mem(struct se_cmd *cmd)
2498 {
2499         transport_free_pages(cmd);
2500
2501         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2502                 core_tmr_release_req(cmd->se_tmr_req);
2503         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2504                 kfree(cmd->t_task_cdb);
2505 }
2506
2507 static void target_release_cmd_kref(struct kref *kref)
2508 {
2509         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2510         struct se_session *se_sess = se_cmd->se_sess;
2511         unsigned long flags;
2512
2513         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2514         if (list_empty(&se_cmd->se_cmd_list)) {
2515                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2516                 target_free_cmd_mem(se_cmd);
2517                 se_cmd->se_tfo->release_cmd(se_cmd);
2518                 return;
2519         }
2520         if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2521                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2522                 target_free_cmd_mem(se_cmd);
2523                 complete(&se_cmd->cmd_wait_comp);
2524                 return;
2525         }
2526         list_del(&se_cmd->se_cmd_list);
2527         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2528
2529         target_free_cmd_mem(se_cmd);
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                 target_free_cmd_mem(se_cmd);
2542                 se_cmd->se_tfo->release_cmd(se_cmd);
2543                 return 1;
2544         }
2545         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
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 }