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 void target_get_session(struct se_session *se_sess)
 387 {
 388         kref_get(&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         struct se_portal_group *se_tpg = nacl->se_tpg;
 427
 428         if (!nacl->dynamic_stop) {
 429                 complete(&nacl->acl_free_comp);
 430                 return;
 431         }
 432
 433         mutex_lock(&se_tpg->acl_node_mutex);
 434         list_del(&nacl->acl_list);
 435         mutex_unlock(&se_tpg->acl_node_mutex);
 436
 437         core_tpg_wait_for_nacl_pr_ref(nacl);
 438         core_free_device_list_for_node(nacl, se_tpg);
 439         kfree(nacl);
 440 }
 441
 442 void target_put_nacl(struct se_node_acl *nacl)
 443 {
 444         kref_put(&nacl->acl_kref, target_complete_nacl);
 445 }
 446 EXPORT_SYMBOL(target_put_nacl);
 447
 448 void transport_deregister_session_configfs(struct se_session *se_sess)
 449 {
 450         struct se_node_acl *se_nacl;
 451         unsigned long flags;
 452         /*
 453          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 454          */
 455         se_nacl = se_sess->se_node_acl;
 456         if (se_nacl) {
 457                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 458                 if (se_nacl->acl_stop == 0)
 459                         list_del(&se_sess->sess_acl_list);
 460                 /*
 461                  * If the session list is empty, then clear the pointer.
 462                  * Otherwise, set the struct se_session pointer from the tail
 463                  * element of the per struct se_node_acl active session list.
 464                  */
 465                 if (list_empty(&se_nacl->acl_sess_list))
 466                         se_nacl->nacl_sess = NULL;
 467                 else {
 468                         se_nacl->nacl_sess = container_of(
 469                                         se_nacl->acl_sess_list.prev,
 470                                         struct se_session, sess_acl_list);
 471                 }
 472                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 473         }
 474 }
 475 EXPORT_SYMBOL(transport_deregister_session_configfs);
 476
 477 void transport_free_session(struct se_session *se_sess)
 478 {
 479         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 480
 481         /*
 482          * Drop the se_node_acl->nacl_kref obtained from within
 483          * core_tpg_get_initiator_node_acl().
 484          */
 485         if (se_nacl) {
 486                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 487                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 488                 unsigned long flags;
 489
 490                 se_sess->se_node_acl = NULL;
 491
 492                 /*
 493                  * Also determine if we need to drop the extra ->cmd_kref if
 494                  * it had been previously dynamically generated, and
 495                  * the endpoint is not caching dynamic ACLs.
 496                  */
 497                 mutex_lock(&se_tpg->acl_node_mutex);
 498                 if (se_nacl->dynamic_node_acl &&
 499                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 500                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 501                         if (list_empty(&se_nacl->acl_sess_list))
 502                                 se_nacl->dynamic_stop = true;
 503                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 504
 505                         if (se_nacl->dynamic_stop)
 506                                 list_del(&se_nacl->acl_list);
 507                 }
 508                 mutex_unlock(&se_tpg->acl_node_mutex);
 509
 510                 if (se_nacl->dynamic_stop)
 511                         target_put_nacl(se_nacl);
 512
 513                 target_put_nacl(se_nacl);
 514         }
 515         if (se_sess->sess_cmd_map) {
 516                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 517                 kvfree(se_sess->sess_cmd_map);
 518         }
 519         kmem_cache_free(se_sess_cache, se_sess);
 520 }
 521 EXPORT_SYMBOL(transport_free_session);
 522
 523 void transport_deregister_session(struct se_session *se_sess)
 524 {
 525         struct se_portal_group *se_tpg = se_sess->se_tpg;
 526         unsigned long flags;
 527
 528         if (!se_tpg) {
 529                 transport_free_session(se_sess);
 530                 return;
 531         }
 532
 533         spin_lock_irqsave(&se_tpg->session_lock, flags);
 534         list_del(&se_sess->sess_list);
 535         se_sess->se_tpg = NULL;
 536         se_sess->fabric_sess_ptr = NULL;
 537         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 538
 539         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 540                 se_tpg->se_tpg_tfo->get_fabric_name());
 541         /*
 542          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 543          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 544          * removal context from within transport_free_session() code.
 545          *
 546          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 547          * to release all remaining generate_node_acl=1 created ACL resources.
 548          */
 549
 550         transport_free_session(se_sess);
 551 }
 552 EXPORT_SYMBOL(transport_deregister_session);
 553
 554 static void target_remove_from_state_list(struct se_cmd *cmd)
 555 {
 556         struct se_device *dev = cmd->se_dev;
 557         unsigned long flags;
 558
 559         if (!dev)
 560                 return;
 561
 562         if (cmd->transport_state & CMD_T_BUSY)
 563                 return;
 564
 565         spin_lock_irqsave(&dev->execute_task_lock, flags);
 566         if (cmd->state_active) {
 567                 list_del(&cmd->state_list);
 568                 cmd->state_active = false;
 569         }
 570         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 571 }
 572
 573 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 574                                     bool write_pending)
 575 {
 576         unsigned long flags;
 577
 578         if (remove_from_lists) {
 579                 target_remove_from_state_list(cmd);
 580
 581                 /*
 582                  * Clear struct se_cmd->se_lun before the handoff to FE.
 583                  */
 584                 cmd->se_lun = NULL;
 585         }
 586
 587         spin_lock_irqsave(&cmd->t_state_lock, flags);
 588         if (write_pending)
 589                 cmd->t_state = TRANSPORT_WRITE_PENDING;
 590
 591         /*
 592          * Determine if frontend context caller is requesting the stopping of
 593          * this command for frontend exceptions.
 594          */
 595         if (cmd->transport_state & CMD_T_STOP) {
 596                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 597                         __func__, __LINE__, cmd->tag);
 598
 599                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 600
 601                 complete_all(&cmd->t_transport_stop_comp);
 602                 return 1;
 603         }
 604
 605         cmd->transport_state &= ~CMD_T_ACTIVE;
 606         if (remove_from_lists) {
 607                 /*
 608                  * Some fabric modules like tcm_loop can release
 609                  * their internally allocated I/O reference now and
 610                  * struct se_cmd now.
 611                  *
 612                  * Fabric modules are expected to return '1' here if the
 613                  * se_cmd being passed is released at this point,
 614                  * or zero if not being released.
 615                  */
 616                 if (cmd->se_tfo->check_stop_free != NULL) {
 617                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 618                         return cmd->se_tfo->check_stop_free(cmd);
 619                 }
 620         }
 621
 622         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 623         return 0;
 624 }
 625
 626 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 627 {
 628         return transport_cmd_check_stop(cmd, true, false);
 629 }
 630
 631 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 632 {
 633         struct se_lun *lun = cmd->se_lun;
 634
 635         if (!lun)
 636                 return;
 637
 638         if (cmpxchg(&cmd->lun_ref_active, true, false))
 639                 percpu_ref_put(&lun->lun_ref);
 640 }
 641
 642 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 643 {
 644         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 645
 646         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 647                 transport_lun_remove_cmd(cmd);
 648         /*
 649          * Allow the fabric driver to unmap any resources before
 650          * releasing the descriptor via TFO->release_cmd()
 651          */
 652         if (remove)
 653                 cmd->se_tfo->aborted_task(cmd);
 654
 655         if (transport_cmd_check_stop_to_fabric(cmd))
 656                 return;
 657         if (remove && ack_kref)
 658                 transport_put_cmd(cmd);
 659 }
 660
 661 static void target_complete_failure_work(struct work_struct *work)
 662 {
 663         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 664
 665         transport_generic_request_failure(cmd,
 666                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 667 }
 668
 669 /*
 670  * Used when asking transport to copy Sense Data from the underlying
 671  * Linux/SCSI struct scsi_cmnd
 672  */
 673 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 674 {
 675         struct se_device *dev = cmd->se_dev;
 676
 677         WARN_ON(!cmd->se_lun);
 678
 679         if (!dev)
 680                 return NULL;
 681
 682         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 683                 return NULL;
 684
 685         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 686
 687         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 688                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 689         return cmd->sense_buffer;
 690 }
 691
 692 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 693 {
 694         struct se_device *dev = cmd->se_dev;
 695         int success = scsi_status == GOOD;
 696         unsigned long flags;
 697
 698         cmd->scsi_status = scsi_status;
 699
 700
 701         spin_lock_irqsave(&cmd->t_state_lock, flags);
 702         cmd->transport_state &= ~CMD_T_BUSY;
 703
 704         if (dev && dev->transport->transport_complete) {
 705                 dev->transport->transport_complete(cmd,
 706                                 cmd->t_data_sg,
 707                                 transport_get_sense_buffer(cmd));
 708                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 709                         success = 1;
 710         }
 711
 712         /*
 713          * See if we are waiting to complete for an exception condition.
 714          */
 715         if (cmd->transport_state & CMD_T_REQUEST_STOP) {
 716                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 717                 complete(&cmd->task_stop_comp);
 718                 return;
 719         }
 720
 721         /*
 722          * Check for case where an explicit ABORT_TASK has been received
 723          * and transport_wait_for_tasks() will be waiting for completion..
 724          */
 725         if (cmd->transport_state & CMD_T_ABORTED ||
 726             cmd->transport_state & CMD_T_STOP) {
 727                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 728                 complete_all(&cmd->t_transport_stop_comp);
 729                 return;
 730         } else if (!success) {
 731                 INIT_WORK(&cmd->work, target_complete_failure_work);
 732         } else {
 733                 INIT_WORK(&cmd->work, target_complete_ok_work);
 734         }
 735
 736         cmd->t_state = TRANSPORT_COMPLETE;
 737         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 738         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 739
 740         queue_work(target_completion_wq, &cmd->work);
 741 }
 742 EXPORT_SYMBOL(target_complete_cmd);
 743
 744 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 745 {
 746         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 747                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 748                         cmd->residual_count += cmd->data_length - length;
 749                 } else {
 750                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 751                         cmd->residual_count = cmd->data_length - length;
 752                 }
 753
 754                 cmd->data_length = length;
 755         }
 756
 757         target_complete_cmd(cmd, scsi_status);
 758 }
 759 EXPORT_SYMBOL(target_complete_cmd_with_length);
 760
 761 static void target_add_to_state_list(struct se_cmd *cmd)
 762 {
 763         struct se_device *dev = cmd->se_dev;
 764         unsigned long flags;
 765
 766         spin_lock_irqsave(&dev->execute_task_lock, flags);
 767         if (!cmd->state_active) {
 768                 list_add_tail(&cmd->state_list, &dev->state_list);
 769                 cmd->state_active = true;
 770         }
 771         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 772 }
 773
 774 /*
 775  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 776  */
 777 static void transport_write_pending_qf(struct se_cmd *cmd);
 778 static void transport_complete_qf(struct se_cmd *cmd);
 779
 780 void target_qf_do_work(struct work_struct *work)
 781 {
 782         struct se_device *dev = container_of(work, struct se_device,
 783                                         qf_work_queue);
 784         LIST_HEAD(qf_cmd_list);
 785         struct se_cmd *cmd, *cmd_tmp;
 786
 787         spin_lock_irq(&dev->qf_cmd_lock);
 788         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 789         spin_unlock_irq(&dev->qf_cmd_lock);
 790
 791         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 792                 list_del(&cmd->se_qf_node);
 793                 atomic_dec_mb(&dev->dev_qf_count);
 794
 795                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 796                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 797                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 798                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 799                         : "UNKNOWN");
 800
 801                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 802                         transport_write_pending_qf(cmd);
 803                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 804                         transport_complete_qf(cmd);
 805         }
 806 }
 807
 808 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 809 {
 810         switch (cmd->data_direction) {
 811         case DMA_NONE:
 812                 return "NONE";
 813         case DMA_FROM_DEVICE:
 814                 return "READ";
 815         case DMA_TO_DEVICE:
 816                 return "WRITE";
 817         case DMA_BIDIRECTIONAL:
 818                 return "BIDI";
 819         default:
 820                 break;
 821         }
 822
 823         return "UNKNOWN";
 824 }
 825
 826 void transport_dump_dev_state(
 827         struct se_device *dev,
 828         char *b,
 829         int *bl)
 830 {
 831         *bl += sprintf(b + *bl, "Status: ");
 832         if (dev->export_count)
 833                 *bl += sprintf(b + *bl, "ACTIVATED");
 834         else
 835                 *bl += sprintf(b + *bl, "DEACTIVATED");
 836
 837         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 838         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 839                 dev->dev_attrib.block_size,
 840                 dev->dev_attrib.hw_max_sectors);
 841         *bl += sprintf(b + *bl, "        ");
 842 }
 843
 844 void transport_dump_vpd_proto_id(
 845         struct t10_vpd *vpd,
 846         unsigned char *p_buf,
 847         int p_buf_len)
 848 {
 849         unsigned char buf[VPD_TMP_BUF_SIZE];
 850         int len;
 851
 852         memset(buf, 0, VPD_TMP_BUF_SIZE);
 853         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 854
 855         switch (vpd->protocol_identifier) {
 856         case 0x00:
 857                 sprintf(buf+len, "Fibre Channel\n");
 858                 break;
 859         case 0x10:
 860                 sprintf(buf+len, "Parallel SCSI\n");
 861                 break;
 862         case 0x20:
 863                 sprintf(buf+len, "SSA\n");
 864                 break;
 865         case 0x30:
 866                 sprintf(buf+len, "IEEE 1394\n");
 867                 break;
 868         case 0x40:
 869                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 870                                 " Protocol\n");
 871                 break;
 872         case 0x50:
 873                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 874                 break;
 875         case 0x60:
 876                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 877                 break;
 878         case 0x70:
 879                 sprintf(buf+len, "Automation/Drive Interface Transport"
 880                                 " Protocol\n");
 881                 break;
 882         case 0x80:
 883                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 884                 break;
 885         default:
 886                 sprintf(buf+len, "Unknown 0x%02x\n",
 887                                 vpd->protocol_identifier);
 888                 break;
 889         }
 890
 891         if (p_buf)
 892                 strncpy(p_buf, buf, p_buf_len);
 893         else
 894                 pr_debug("%s", buf);
 895 }
 896
 897 void
 898 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 899 {
 900         /*
 901          * Check if the Protocol Identifier Valid (PIV) bit is set..
 902          *
 903          * from spc3r23.pdf section 7.5.1
 904          */
 905          if (page_83[1] & 0x80) {
 906                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 907                 vpd->protocol_identifier_set = 1;
 908                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 909         }
 910 }
 911 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 912
 913 int transport_dump_vpd_assoc(
 914         struct t10_vpd *vpd,
 915         unsigned char *p_buf,
 916         int p_buf_len)
 917 {
 918         unsigned char buf[VPD_TMP_BUF_SIZE];
 919         int ret = 0;
 920         int len;
 921
 922         memset(buf, 0, VPD_TMP_BUF_SIZE);
 923         len = sprintf(buf, "T10 VPD Identifier Association: ");
 924
 925         switch (vpd->association) {
 926         case 0x00:
 927                 sprintf(buf+len, "addressed logical unit\n");
 928                 break;
 929         case 0x10:
 930                 sprintf(buf+len, "target port\n");
 931                 break;
 932         case 0x20:
 933                 sprintf(buf+len, "SCSI target device\n");
 934                 break;
 935         default:
 936                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 937                 ret = -EINVAL;
 938                 break;
 939         }
 940
 941         if (p_buf)
 942                 strncpy(p_buf, buf, p_buf_len);
 943         else
 944                 pr_debug("%s", buf);
 945
 946         return ret;
 947 }
 948
 949 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 950 {
 951         /*
 952          * The VPD identification association..
 953          *
 954          * from spc3r23.pdf Section 7.6.3.1 Table 297
 955          */
 956         vpd->association = (page_83[1] & 0x30);
 957         return transport_dump_vpd_assoc(vpd, NULL, 0);
 958 }
 959 EXPORT_SYMBOL(transport_set_vpd_assoc);
 960
 961 int transport_dump_vpd_ident_type(
 962         struct t10_vpd *vpd,
 963         unsigned char *p_buf,
 964         int p_buf_len)
 965 {
 966         unsigned char buf[VPD_TMP_BUF_SIZE];
 967         int ret = 0;
 968         int len;
 969
 970         memset(buf, 0, VPD_TMP_BUF_SIZE);
 971         len = sprintf(buf, "T10 VPD Identifier Type: ");
 972
 973         switch (vpd->device_identifier_type) {
 974         case 0x00:
 975                 sprintf(buf+len, "Vendor specific\n");
 976                 break;
 977         case 0x01:
 978                 sprintf(buf+len, "T10 Vendor ID based\n");
 979                 break;
 980         case 0x02:
 981                 sprintf(buf+len, "EUI-64 based\n");
 982                 break;
 983         case 0x03:
 984                 sprintf(buf+len, "NAA\n");
 985                 break;
 986         case 0x04:
 987                 sprintf(buf+len, "Relative target port identifier\n");
 988                 break;
 989         case 0x08:
 990                 sprintf(buf+len, "SCSI name string\n");
 991                 break;
 992         default:
 993                 sprintf(buf+len, "Unsupported: 0x%02x\n",
 994                                 vpd->device_identifier_type);
 995                 ret = -EINVAL;
 996                 break;
 997         }
 998
 999         if (p_buf) {
1000                 if (p_buf_len < strlen(buf)+1)
1001                         return -EINVAL;
1002                 strncpy(p_buf, buf, p_buf_len);
1003         } else {
1004                 pr_debug("%s", buf);
1005         }
1006
1007         return ret;
1008 }
1009
1010 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1011 {
1012         /*
1013          * The VPD identifier type..
1014          *
1015          * from spc3r23.pdf Section 7.6.3.1 Table 298
1016          */
1017         vpd->device_identifier_type = (page_83[1] & 0x0f);
1018         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1019 }
1020 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1021
1022 int transport_dump_vpd_ident(
1023         struct t10_vpd *vpd,
1024         unsigned char *p_buf,
1025         int p_buf_len)
1026 {
1027         unsigned char buf[VPD_TMP_BUF_SIZE];
1028         int ret = 0;
1029
1030         memset(buf, 0, VPD_TMP_BUF_SIZE);
1031
1032         switch (vpd->device_identifier_code_set) {
1033         case 0x01: /* Binary */
1034                 snprintf(buf, sizeof(buf),
1035                         "T10 VPD Binary Device Identifier: %s\n",
1036                         &vpd->device_identifier[0]);
1037                 break;
1038         case 0x02: /* ASCII */
1039                 snprintf(buf, sizeof(buf),
1040                         "T10 VPD ASCII Device Identifier: %s\n",
1041                         &vpd->device_identifier[0]);
1042                 break;
1043         case 0x03: /* UTF-8 */
1044                 snprintf(buf, sizeof(buf),
1045                         "T10 VPD UTF-8 Device Identifier: %s\n",
1046                         &vpd->device_identifier[0]);
1047                 break;
1048         default:
1049                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1050                         " 0x%02x", vpd->device_identifier_code_set);
1051                 ret = -EINVAL;
1052                 break;
1053         }
1054
1055         if (p_buf)
1056                 strncpy(p_buf, buf, p_buf_len);
1057         else
1058                 pr_debug("%s", buf);
1059
1060         return ret;
1061 }
1062
1063 int
1064 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1065 {
1066         static const char hex_str[] = "0123456789abcdef";
1067         int j = 0, i = 4; /* offset to start of the identifier */
1068
1069         /*
1070          * The VPD Code Set (encoding)
1071          *
1072          * from spc3r23.pdf Section 7.6.3.1 Table 296
1073          */
1074         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1075         switch (vpd->device_identifier_code_set) {
1076         case 0x01: /* Binary */
1077                 vpd->device_identifier[j++] =
1078                                 hex_str[vpd->device_identifier_type];
1079                 while (i < (4 + page_83[3])) {
1080                         vpd->device_identifier[j++] =
1081                                 hex_str[(page_83[i] & 0xf0) >> 4];
1082                         vpd->device_identifier[j++] =
1083                                 hex_str[page_83[i] & 0x0f];
1084                         i++;
1085                 }
1086                 break;
1087         case 0x02: /* ASCII */
1088         case 0x03: /* UTF-8 */
1089                 while (i < (4 + page_83[3]))
1090                         vpd->device_identifier[j++] = page_83[i++];
1091                 break;
1092         default:
1093                 break;
1094         }
1095
1096         return transport_dump_vpd_ident(vpd, NULL, 0);
1097 }
1098 EXPORT_SYMBOL(transport_set_vpd_ident);
1099
1100 static sense_reason_t
1101 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1102                                unsigned int size)
1103 {
1104         u32 mtl;
1105
1106         if (!cmd->se_tfo->max_data_sg_nents)
1107                 return TCM_NO_SENSE;
1108         /*
1109          * Check if fabric enforced maximum SGL entries per I/O descriptor
1110          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1111          * residual_count and reduce original cmd->data_length to maximum
1112          * length based on single PAGE_SIZE entry scatter-lists.
1113          */
1114         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1115         if (cmd->data_length > mtl) {
1116                 /*
1117                  * If an existing CDB overflow is present, calculate new residual
1118                  * based on CDB size minus fabric maximum transfer length.
1119                  *
1120                  * If an existing CDB underflow is present, calculate new residual
1121                  * based on original cmd->data_length minus fabric maximum transfer
1122                  * length.
1123                  *
1124                  * Otherwise, set the underflow residual based on cmd->data_length
1125                  * minus fabric maximum transfer length.
1126                  */
1127                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1128                         cmd->residual_count = (size - mtl);
1129                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1130                         u32 orig_dl = size + cmd->residual_count;
1131                         cmd->residual_count = (orig_dl - mtl);
1132                 } else {
1133                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1134                         cmd->residual_count = (cmd->data_length - mtl);
1135                 }
1136                 cmd->data_length = mtl;
1137                 /*
1138                  * Reset sbc_check_prot() calculated protection payload
1139                  * length based upon the new smaller MTL.
1140                  */
1141                 if (cmd->prot_length) {
1142                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1143                         cmd->prot_length = dev->prot_length * sectors;
1144                 }
1145         }
1146         return TCM_NO_SENSE;
1147 }
1148
1149 sense_reason_t
1150 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1151 {
1152         struct se_device *dev = cmd->se_dev;
1153
1154         if (cmd->unknown_data_length) {
1155                 cmd->data_length = size;
1156         } else if (size != cmd->data_length) {
1157                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1158                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1159                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1160                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1161
1162                 if (cmd->data_direction == DMA_TO_DEVICE &&
1163                     cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1164                         pr_err("Rejecting underflow/overflow WRITE data\n");
1165                         return TCM_INVALID_CDB_FIELD;
1166                 }
1167                 /*
1168                  * Reject READ_* or WRITE_* with overflow/underflow for
1169                  * type SCF_SCSI_DATA_CDB.
1170                  */
1171                 if (dev->dev_attrib.block_size != 512)  {
1172                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1173                                 " CDB on non 512-byte sector setup subsystem"
1174                                 " plugin: %s\n", dev->transport->name);
1175                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1176                         return TCM_INVALID_CDB_FIELD;
1177                 }
1178                 /*
1179                  * For the overflow case keep the existing fabric provided
1180                  * ->data_length.  Otherwise for the underflow case, reset
1181                  * ->data_length to the smaller SCSI expected data transfer
1182                  * length.
1183                  */
1184                 if (size > cmd->data_length) {
1185                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1186                         cmd->residual_count = (size - cmd->data_length);
1187                 } else {
1188                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1189                         cmd->residual_count = (cmd->data_length - size);
1190                         cmd->data_length = size;
1191                 }
1192         }
1193
1194         return target_check_max_data_sg_nents(cmd, dev, size);
1195
1196 }
1197
1198 /*
1199  * Used by fabric modules containing a local struct se_cmd within their
1200  * fabric dependent per I/O descriptor.
1201  *
1202  * Preserves the value of @cmd->tag.
1203  */
1204 void transport_init_se_cmd(
1205         struct se_cmd *cmd,
1206         const struct target_core_fabric_ops *tfo,
1207         struct se_session *se_sess,
1208         u32 data_length,
1209         int data_direction,
1210         int task_attr,
1211         unsigned char *sense_buffer)
1212 {
1213         INIT_LIST_HEAD(&cmd->se_delayed_node);
1214         INIT_LIST_HEAD(&cmd->se_qf_node);
1215         INIT_LIST_HEAD(&cmd->se_cmd_list);
1216         INIT_LIST_HEAD(&cmd->state_list);
1217         init_completion(&cmd->t_transport_stop_comp);
1218         init_completion(&cmd->cmd_wait_comp);
1219         init_completion(&cmd->task_stop_comp);
1220         spin_lock_init(&cmd->t_state_lock);
1221         kref_init(&cmd->cmd_kref);
1222         cmd->transport_state = CMD_T_DEV_ACTIVE;
1223
1224         cmd->se_tfo = tfo;
1225         cmd->se_sess = se_sess;
1226         cmd->data_length = data_length;
1227         cmd->data_direction = data_direction;
1228         cmd->sam_task_attr = task_attr;
1229         cmd->sense_buffer = sense_buffer;
1230
1231         cmd->state_active = false;
1232 }
1233 EXPORT_SYMBOL(transport_init_se_cmd);
1234
1235 static sense_reason_t
1236 transport_check_alloc_task_attr(struct se_cmd *cmd)
1237 {
1238         struct se_device *dev = cmd->se_dev;
1239
1240         /*
1241          * Check if SAM Task Attribute emulation is enabled for this
1242          * struct se_device storage object
1243          */
1244         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1245                 return 0;
1246
1247         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1248                 pr_debug("SAM Task Attribute ACA"
1249                         " emulation is not supported\n");
1250                 return TCM_INVALID_CDB_FIELD;
1251         }
1252
1253         return 0;
1254 }
1255
1256 sense_reason_t
1257 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1258 {
1259         struct se_device *dev = cmd->se_dev;
1260         sense_reason_t ret;
1261
1262         /*
1263          * Ensure that the received CDB is less than the max (252 + 8) bytes
1264          * for VARIABLE_LENGTH_CMD
1265          */
1266         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1267                 pr_err("Received SCSI CDB with command_size: %d that"
1268                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1269                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1270                 return TCM_INVALID_CDB_FIELD;
1271         }
1272         /*
1273          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1274          * allocate the additional extended CDB buffer now..  Otherwise
1275          * setup the pointer from __t_task_cdb to t_task_cdb.
1276          */
1277         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1278                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1279                                                 GFP_KERNEL);
1280                 if (!cmd->t_task_cdb) {
1281                         pr_err("Unable to allocate cmd->t_task_cdb"
1282                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1283                                 scsi_command_size(cdb),
1284                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1285                         return TCM_OUT_OF_RESOURCES;
1286                 }
1287         } else
1288                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1289         /*
1290          * Copy the original CDB into cmd->
1291          */
1292         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1293
1294         trace_target_sequencer_start(cmd);
1295
1296         ret = dev->transport->parse_cdb(cmd);
1297         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1298                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1299                                     cmd->se_tfo->get_fabric_name(),
1300                                     cmd->se_sess->se_node_acl->initiatorname,
1301                                     cmd->t_task_cdb[0]);
1302         if (ret)
1303                 return ret;
1304
1305         ret = transport_check_alloc_task_attr(cmd);
1306         if (ret)
1307                 return ret;
1308
1309         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1310         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1311         return 0;
1312 }
1313 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1314
1315 /*
1316  * Used by fabric module frontends to queue tasks directly.
1317  * Many only be used from process context only
1318  */
1319 int transport_handle_cdb_direct(
1320         struct se_cmd *cmd)
1321 {
1322         sense_reason_t ret;
1323
1324         if (!cmd->se_lun) {
1325                 dump_stack();
1326                 pr_err("cmd->se_lun is NULL\n");
1327                 return -EINVAL;
1328         }
1329         if (in_interrupt()) {
1330                 dump_stack();
1331                 pr_err("transport_generic_handle_cdb cannot be called"
1332                                 " from interrupt context\n");
1333                 return -EINVAL;
1334         }
1335         /*
1336          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1337          * outstanding descriptors are handled correctly during shutdown via
1338          * transport_wait_for_tasks()
1339          *
1340          * Also, we don't take cmd->t_state_lock here as we only expect
1341          * this to be called for initial descriptor submission.
1342          */
1343         cmd->t_state = TRANSPORT_NEW_CMD;
1344         cmd->transport_state |= CMD_T_ACTIVE;
1345
1346         /*
1347          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1348          * so follow TRANSPORT_NEW_CMD processing thread context usage
1349          * and call transport_generic_request_failure() if necessary..
1350          */
1351         ret = transport_generic_new_cmd(cmd);
1352         if (ret)
1353                 transport_generic_request_failure(cmd, ret);
1354         return 0;
1355 }
1356 EXPORT_SYMBOL(transport_handle_cdb_direct);
1357
1358 sense_reason_t
1359 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1360                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1361 {
1362         if (!sgl || !sgl_count)
1363                 return 0;
1364
1365         /*
1366          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1367          * scatterlists already have been set to follow what the fabric
1368          * passes for the original expected data transfer length.
1369          */
1370         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1371                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1372                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1373                 return TCM_INVALID_CDB_FIELD;
1374         }
1375
1376         cmd->t_data_sg = sgl;
1377         cmd->t_data_nents = sgl_count;
1378         cmd->t_bidi_data_sg = sgl_bidi;
1379         cmd->t_bidi_data_nents = sgl_bidi_count;
1380
1381         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1382         return 0;
1383 }
1384
1385 /*
1386  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1387  *                       se_cmd + use pre-allocated SGL memory.
1388  *
1389  * @se_cmd: command descriptor to submit
1390  * @se_sess: associated se_sess for endpoint
1391  * @cdb: pointer to SCSI CDB
1392  * @sense: pointer to SCSI sense buffer
1393  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1394  * @data_length: fabric expected data transfer length
1395  * @task_addr: SAM task attribute
1396  * @data_dir: DMA data direction
1397  * @flags: flags for command submission from target_sc_flags_tables
1398  * @sgl: struct scatterlist memory for unidirectional mapping
1399  * @sgl_count: scatterlist count for unidirectional mapping
1400  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1401  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1402  * @sgl_prot: struct scatterlist memory protection information
1403  * @sgl_prot_count: scatterlist count for protection information
1404  *
1405  * Task tags are supported if the caller has set @se_cmd->tag.
1406  *
1407  * Returns non zero to signal active I/O shutdown failure.  All other
1408  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1409  * but still return zero here.
1410  *
1411  * This may only be called from process context, and also currently
1412  * assumes internal allocation of fabric payload buffer by target-core.
1413  */
1414 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1415                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1416                 u32 data_length, int task_attr, int data_dir, int flags,
1417                 struct scatterlist *sgl, u32 sgl_count,
1418                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1419                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1420 {
1421         struct se_portal_group *se_tpg;
1422         sense_reason_t rc;
1423         int ret;
1424
1425         se_tpg = se_sess->se_tpg;
1426         BUG_ON(!se_tpg);
1427         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1428         BUG_ON(in_interrupt());
1429         /*
1430          * Initialize se_cmd for target operation.  From this point
1431          * exceptions are handled by sending exception status via
1432          * target_core_fabric_ops->queue_status() callback
1433          */
1434         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1435                                 data_length, data_dir, task_attr, sense);
1436         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1437                 se_cmd->unknown_data_length = 1;
1438         /*
1439          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1440          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1441          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1442          * kref_put() to happen during fabric packet acknowledgement.
1443          */
1444         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1445         if (ret)
1446                 return ret;
1447         /*
1448          * Signal bidirectional data payloads to target-core
1449          */
1450         if (flags & TARGET_SCF_BIDI_OP)
1451                 se_cmd->se_cmd_flags |= SCF_BIDI;
1452         /*
1453          * Locate se_lun pointer and attach it to struct se_cmd
1454          */
1455         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1456         if (rc) {
1457                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1458                 target_put_sess_cmd(se_cmd);
1459                 return 0;
1460         }
1461
1462         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1463         if (rc != 0) {
1464                 transport_generic_request_failure(se_cmd, rc);
1465                 return 0;
1466         }
1467
1468         /*
1469          * Save pointers for SGLs containing protection information,
1470          * if present.
1471          */
1472         if (sgl_prot_count) {
1473                 se_cmd->t_prot_sg = sgl_prot;
1474                 se_cmd->t_prot_nents = sgl_prot_count;
1475                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1476         }
1477
1478         /*
1479          * When a non zero sgl_count has been passed perform SGL passthrough
1480          * mapping for pre-allocated fabric memory instead of having target
1481          * core perform an internal SGL allocation..
1482          */
1483         if (sgl_count != 0) {
1484                 BUG_ON(!sgl);
1485
1486                 /*
1487                  * A work-around for tcm_loop as some userspace code via
1488                  * scsi-generic do not memset their associated read buffers,
1489                  * so go ahead and do that here for type non-data CDBs.  Also
1490                  * note that this is currently guaranteed to be a single SGL
1491                  * for this case by target core in target_setup_cmd_from_cdb()
1492                  * -> transport_generic_cmd_sequencer().
1493                  */
1494                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1495                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1496                         unsigned char *buf = NULL;
1497
1498                         if (sgl)
1499                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1500
1501                         if (buf) {
1502                                 memset(buf, 0, sgl->length);
1503                                 kunmap(sg_page(sgl));
1504                         }
1505                 }
1506
1507                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1508                                 sgl_bidi, sgl_bidi_count);
1509                 if (rc != 0) {
1510                         transport_generic_request_failure(se_cmd, rc);
1511                         return 0;
1512                 }
1513         }
1514
1515         /*
1516          * Check if we need to delay processing because of ALUA
1517          * Active/NonOptimized primary access state..
1518          */
1519         core_alua_check_nonop_delay(se_cmd);
1520
1521         transport_handle_cdb_direct(se_cmd);
1522         return 0;
1523 }
1524 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1525
1526 /*
1527  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1528  *
1529  * @se_cmd: command descriptor to submit
1530  * @se_sess: associated se_sess for endpoint
1531  * @cdb: pointer to SCSI CDB
1532  * @sense: pointer to SCSI sense buffer
1533  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1534  * @data_length: fabric expected data transfer length
1535  * @task_addr: SAM task attribute
1536  * @data_dir: DMA data direction
1537  * @flags: flags for command submission from target_sc_flags_tables
1538  *
1539  * Task tags are supported if the caller has set @se_cmd->tag.
1540  *
1541  * Returns non zero to signal active I/O shutdown failure.  All other
1542  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1543  * but still return zero here.
1544  *
1545  * This may only be called from process context, and also currently
1546  * assumes internal allocation of fabric payload buffer by target-core.
1547  *
1548  * It also assumes interal target core SGL memory allocation.
1549  */
1550 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1551                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1552                 u32 data_length, int task_attr, int data_dir, int flags)
1553 {
1554         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1555                         unpacked_lun, data_length, task_attr, data_dir,
1556                         flags, NULL, 0, NULL, 0, NULL, 0);
1557 }
1558 EXPORT_SYMBOL(target_submit_cmd);
1559
1560 static void target_complete_tmr_failure(struct work_struct *work)
1561 {
1562         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1563
1564         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1565         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1566
1567         transport_cmd_check_stop_to_fabric(se_cmd);
1568 }
1569
1570 /**
1571  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1572  *                     for TMR CDBs
1573  *
1574  * @se_cmd: command descriptor to submit
1575  * @se_sess: associated se_sess for endpoint
1576  * @sense: pointer to SCSI sense buffer
1577  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1578  * @fabric_context: fabric context for TMR req
1579  * @tm_type: Type of TM request
1580  * @gfp: gfp type for caller
1581  * @tag: referenced task tag for TMR_ABORT_TASK
1582  * @flags: submit cmd flags
1583  *
1584  * Callable from all contexts.
1585  **/
1586
1587 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1588                 unsigned char *sense, u64 unpacked_lun,
1589                 void *fabric_tmr_ptr, unsigned char tm_type,
1590                 gfp_t gfp, unsigned int tag, int flags)
1591 {
1592         struct se_portal_group *se_tpg;
1593         int ret;
1594
1595         se_tpg = se_sess->se_tpg;
1596         BUG_ON(!se_tpg);
1597
1598         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1599                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1600         /*
1601          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1602          * allocation failure.
1603          */
1604         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1605         if (ret < 0)
1606                 return -ENOMEM;
1607
1608         if (tm_type == TMR_ABORT_TASK)
1609                 se_cmd->se_tmr_req->ref_task_tag = tag;
1610
1611         /* See target_submit_cmd for commentary */
1612         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1613         if (ret) {
1614                 core_tmr_release_req(se_cmd->se_tmr_req);
1615                 return ret;
1616         }
1617
1618         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1619         if (ret) {
1620                 /*
1621                  * For callback during failure handling, push this work off
1622                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1623                  */
1624                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1625                 schedule_work(&se_cmd->work);
1626                 return 0;
1627         }
1628         transport_generic_handle_tmr(se_cmd);
1629         return 0;
1630 }
1631 EXPORT_SYMBOL(target_submit_tmr);
1632
1633 /*
1634  * If the cmd is active, request it to be stopped and sleep until it
1635  * has completed.
1636  */
1637 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1638         __releases(&cmd->t_state_lock)
1639         __acquires(&cmd->t_state_lock)
1640 {
1641         bool was_active = false;
1642
1643         if (cmd->transport_state & CMD_T_BUSY) {
1644                 cmd->transport_state |= CMD_T_REQUEST_STOP;
1645                 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1646
1647                 pr_debug("cmd %p waiting to complete\n", cmd);
1648                 wait_for_completion(&cmd->task_stop_comp);
1649                 pr_debug("cmd %p stopped successfully\n", cmd);
1650
1651                 spin_lock_irqsave(&cmd->t_state_lock, *flags);
1652                 cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1653                 cmd->transport_state &= ~CMD_T_BUSY;
1654                 was_active = true;
1655         }
1656
1657         return was_active;
1658 }
1659
1660 /*
1661  * Handle SAM-esque emulation for generic transport request failures.
1662  */
1663 void transport_generic_request_failure(struct se_cmd *cmd,
1664                 sense_reason_t sense_reason)
1665 {
1666         int ret = 0, post_ret = 0;
1667
1668         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1669                 " CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1670         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1671                 cmd->se_tfo->get_cmd_state(cmd),
1672                 cmd->t_state, sense_reason);
1673         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1674                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1675                 (cmd->transport_state & CMD_T_STOP) != 0,
1676                 (cmd->transport_state & CMD_T_SENT) != 0);
1677
1678         /*
1679          * For SAM Task Attribute emulation for failed struct se_cmd
1680          */
1681         transport_complete_task_attr(cmd);
1682         /*
1683          * Handle special case for COMPARE_AND_WRITE failure, where the
1684          * callback is expected to drop the per device ->caw_sem.
1685          */
1686         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1687              cmd->transport_complete_callback)
1688                 cmd->transport_complete_callback(cmd, false, &post_ret);
1689
1690         switch (sense_reason) {
1691         case TCM_NON_EXISTENT_LUN:
1692         case TCM_UNSUPPORTED_SCSI_OPCODE:
1693         case TCM_INVALID_CDB_FIELD:
1694         case TCM_INVALID_PARAMETER_LIST:
1695         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1696         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1697         case TCM_UNKNOWN_MODE_PAGE:
1698         case TCM_WRITE_PROTECTED:
1699         case TCM_ADDRESS_OUT_OF_RANGE:
1700         case TCM_CHECK_CONDITION_ABORT_CMD:
1701         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1702         case TCM_CHECK_CONDITION_NOT_READY:
1703         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1704         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1705         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1706         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1707                 break;
1708         case TCM_OUT_OF_RESOURCES:
1709                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1710                 break;
1711         case TCM_RESERVATION_CONFLICT:
1712                 /*
1713                  * No SENSE Data payload for this case, set SCSI Status
1714                  * and queue the response to $FABRIC_MOD.
1715                  *
1716                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1717                  */
1718                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1719                 /*
1720                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1721                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1722                  * CONFLICT STATUS.
1723                  *
1724                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1725                  */
1726                 if (cmd->se_sess &&
1727                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1728                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1729                                                cmd->orig_fe_lun, 0x2C,
1730                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1731                 }
1732                 trace_target_cmd_complete(cmd);
1733                 ret = cmd->se_tfo->queue_status(cmd);
1734                 if (ret == -EAGAIN || ret == -ENOMEM)
1735                         goto queue_full;
1736                 goto check_stop;
1737         default:
1738                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1739                         cmd->t_task_cdb[0], sense_reason);
1740                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1741                 break;
1742         }
1743
1744         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1745         if (ret == -EAGAIN || ret == -ENOMEM)
1746                 goto queue_full;
1747
1748 check_stop:
1749         transport_lun_remove_cmd(cmd);
1750         transport_cmd_check_stop_to_fabric(cmd);
1751         return;
1752
1753 queue_full:
1754         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1755         transport_handle_queue_full(cmd, cmd->se_dev);
1756 }
1757 EXPORT_SYMBOL(transport_generic_request_failure);
1758
1759 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1760 {
1761         sense_reason_t ret;
1762
1763         if (!cmd->execute_cmd) {
1764                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1765                 goto err;
1766         }
1767         if (do_checks) {
1768                 /*
1769                  * Check for an existing UNIT ATTENTION condition after
1770                  * target_handle_task_attr() has done SAM task attr
1771                  * checking, and possibly have already defered execution
1772                  * out to target_restart_delayed_cmds() context.
1773                  */
1774                 ret = target_scsi3_ua_check(cmd);
1775                 if (ret)
1776                         goto err;
1777
1778                 ret = target_alua_state_check(cmd);
1779                 if (ret)
1780                         goto err;
1781
1782                 ret = target_check_reservation(cmd);
1783                 if (ret) {
1784                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1785                         goto err;
1786                 }
1787         }
1788
1789         ret = cmd->execute_cmd(cmd);
1790         if (!ret)
1791                 return;
1792 err:
1793         spin_lock_irq(&cmd->t_state_lock);
1794         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1795         spin_unlock_irq(&cmd->t_state_lock);
1796
1797         transport_generic_request_failure(cmd, ret);
1798 }
1799
1800 static int target_write_prot_action(struct se_cmd *cmd)
1801 {
1802         u32 sectors;
1803         /*
1804          * Perform WRITE_INSERT of PI using software emulation when backend
1805          * device has PI enabled, if the transport has not already generated
1806          * PI using hardware WRITE_INSERT offload.
1807          */
1808         switch (cmd->prot_op) {
1809         case TARGET_PROT_DOUT_INSERT:
1810                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1811                         sbc_dif_generate(cmd);
1812                 break;
1813         case TARGET_PROT_DOUT_STRIP:
1814                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1815                         break;
1816
1817                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1818                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1819                                              sectors, 0, cmd->t_prot_sg, 0);
1820                 if (unlikely(cmd->pi_err)) {
1821                         spin_lock_irq(&cmd->t_state_lock);
1822                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1823                         spin_unlock_irq(&cmd->t_state_lock);
1824                         transport_generic_request_failure(cmd, cmd->pi_err);
1825                         return -1;
1826                 }
1827                 break;
1828         default:
1829                 break;
1830         }
1831
1832         return 0;
1833 }
1834
1835 static bool target_handle_task_attr(struct se_cmd *cmd)
1836 {
1837         struct se_device *dev = cmd->se_dev;
1838
1839         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1840                 return false;
1841
1842         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1843
1844         /*
1845          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1846          * to allow the passed struct se_cmd list of tasks to the front of the list.
1847          */
1848         switch (cmd->sam_task_attr) {
1849         case TCM_HEAD_TAG:
1850                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1851                          cmd->t_task_cdb[0]);
1852                 return false;
1853         case TCM_ORDERED_TAG:
1854                 atomic_inc_mb(&dev->dev_ordered_sync);
1855
1856                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1857                          cmd->t_task_cdb[0]);
1858
1859                 /*
1860                  * Execute an ORDERED command if no other older commands
1861                  * exist that need to be completed first.
1862                  */
1863                 if (!atomic_read(&dev->simple_cmds))
1864                         return false;
1865                 break;
1866         default:
1867                 /*
1868                  * For SIMPLE and UNTAGGED Task Attribute commands
1869                  */
1870                 atomic_inc_mb(&dev->simple_cmds);
1871                 break;
1872         }
1873
1874         if (atomic_read(&dev->dev_ordered_sync) == 0)
1875                 return false;
1876
1877         spin_lock(&dev->delayed_cmd_lock);
1878         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1879         spin_unlock(&dev->delayed_cmd_lock);
1880
1881         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1882                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1883         return true;
1884 }
1885
1886 static int __transport_check_aborted_status(struct se_cmd *, int);
1887
1888 void target_execute_cmd(struct se_cmd *cmd)
1889 {
1890         /*
1891          * Determine if frontend context caller is requesting the stopping of
1892          * this command for frontend exceptions.
1893          *
1894          * If the received CDB has aleady been aborted stop processing it here.
1895          */
1896         spin_lock_irq(&cmd->t_state_lock);
1897         if (__transport_check_aborted_status(cmd, 1)) {
1898                 spin_unlock_irq(&cmd->t_state_lock);
1899                 return;
1900         }
1901         if (cmd->transport_state & CMD_T_STOP) {
1902                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1903                         __func__, __LINE__, cmd->tag);
1904
1905                 spin_unlock_irq(&cmd->t_state_lock);
1906                 complete_all(&cmd->t_transport_stop_comp);
1907                 return;
1908         }
1909
1910         cmd->t_state = TRANSPORT_PROCESSING;
1911         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1912         spin_unlock_irq(&cmd->t_state_lock);
1913
1914         if (target_write_prot_action(cmd))
1915                 return;
1916
1917         if (target_handle_task_attr(cmd)) {
1918                 spin_lock_irq(&cmd->t_state_lock);
1919                 cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1920                 spin_unlock_irq(&cmd->t_state_lock);
1921                 return;
1922         }
1923
1924         __target_execute_cmd(cmd, true);
1925 }
1926 EXPORT_SYMBOL(target_execute_cmd);
1927
1928 /*
1929  * Process all commands up to the last received ORDERED task attribute which
1930  * requires another blocking boundary
1931  */
1932 static void target_restart_delayed_cmds(struct se_device *dev)
1933 {
1934         for (;;) {
1935                 struct se_cmd *cmd;
1936
1937                 spin_lock(&dev->delayed_cmd_lock);
1938                 if (list_empty(&dev->delayed_cmd_list)) {
1939                         spin_unlock(&dev->delayed_cmd_lock);
1940                         break;
1941                 }
1942
1943                 cmd = list_entry(dev->delayed_cmd_list.next,
1944                                  struct se_cmd, se_delayed_node);
1945                 list_del(&cmd->se_delayed_node);
1946                 spin_unlock(&dev->delayed_cmd_lock);
1947
1948                 __target_execute_cmd(cmd, true);
1949
1950                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1951                         break;
1952         }
1953 }
1954
1955 /*
1956  * Called from I/O completion to determine which dormant/delayed
1957  * and ordered cmds need to have their tasks added to the execution queue.
1958  */
1959 static void transport_complete_task_attr(struct se_cmd *cmd)
1960 {
1961         struct se_device *dev = cmd->se_dev;
1962
1963         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1964                 return;
1965
1966         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
1967                 goto restart;
1968
1969         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1970                 atomic_dec_mb(&dev->simple_cmds);
1971                 dev->dev_cur_ordered_id++;
1972                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for SIMPLE\n",
1973                          dev->dev_cur_ordered_id);
1974         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1975                 dev->dev_cur_ordered_id++;
1976                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1977                          dev->dev_cur_ordered_id);
1978         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1979                 atomic_dec_mb(&dev->dev_ordered_sync);
1980
1981                 dev->dev_cur_ordered_id++;
1982                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1983                          dev->dev_cur_ordered_id);
1984         }
1985 restart:
1986         target_restart_delayed_cmds(dev);
1987 }
1988
1989 static void transport_complete_qf(struct se_cmd *cmd)
1990 {
1991         int ret = 0;
1992
1993         transport_complete_task_attr(cmd);
1994
1995         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1996                 trace_target_cmd_complete(cmd);
1997                 ret = cmd->se_tfo->queue_status(cmd);
1998                 goto out;
1999         }
2000
2001         switch (cmd->data_direction) {
2002         case DMA_FROM_DEVICE:
2003                 trace_target_cmd_complete(cmd);
2004                 ret = cmd->se_tfo->queue_data_in(cmd);
2005                 break;
2006         case DMA_TO_DEVICE:
2007                 if (cmd->se_cmd_flags & SCF_BIDI) {
2008                         ret = cmd->se_tfo->queue_data_in(cmd);
2009                         break;
2010                 }
2011                 /* Fall through for DMA_TO_DEVICE */
2012         case DMA_NONE:
2013                 trace_target_cmd_complete(cmd);
2014                 ret = cmd->se_tfo->queue_status(cmd);
2015                 break;
2016         default:
2017                 break;
2018         }
2019
2020 out:
2021         if (ret < 0) {
2022                 transport_handle_queue_full(cmd, cmd->se_dev);
2023                 return;
2024         }
2025         transport_lun_remove_cmd(cmd);
2026         transport_cmd_check_stop_to_fabric(cmd);
2027 }
2028
2029 static void transport_handle_queue_full(
2030         struct se_cmd *cmd,
2031         struct se_device *dev)
2032 {
2033         spin_lock_irq(&dev->qf_cmd_lock);
2034         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2035         atomic_inc_mb(&dev->dev_qf_count);
2036         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2037
2038         schedule_work(&cmd->se_dev->qf_work_queue);
2039 }
2040
2041 static bool target_read_prot_action(struct se_cmd *cmd)
2042 {
2043         switch (cmd->prot_op) {
2044         case TARGET_PROT_DIN_STRIP:
2045                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2046                         u32 sectors = cmd->data_length >>
2047                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2048
2049                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2050                                                      sectors, 0, cmd->t_prot_sg,
2051                                                      0);
2052                         if (cmd->pi_err)
2053                                 return true;
2054                 }
2055                 break;
2056         case TARGET_PROT_DIN_INSERT:
2057                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2058                         break;
2059
2060                 sbc_dif_generate(cmd);
2061                 break;
2062         default:
2063                 break;
2064         }
2065
2066         return false;
2067 }
2068
2069 static void target_complete_ok_work(struct work_struct *work)
2070 {
2071         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2072         int ret;
2073
2074         /*
2075          * Check if we need to move delayed/dormant tasks from cmds on the
2076          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2077          * Attribute.
2078          */
2079         transport_complete_task_attr(cmd);
2080
2081         /*
2082          * Check to schedule QUEUE_FULL work, or execute an existing
2083          * cmd->transport_qf_callback()
2084          */
2085         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2086                 schedule_work(&cmd->se_dev->qf_work_queue);
2087
2088         /*
2089          * Check if we need to send a sense buffer from
2090          * the struct se_cmd in question.
2091          */
2092         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2093                 WARN_ON(!cmd->scsi_status);
2094                 ret = transport_send_check_condition_and_sense(
2095                                         cmd, 0, 1);
2096                 if (ret == -EAGAIN || ret == -ENOMEM)
2097                         goto queue_full;
2098
2099                 transport_lun_remove_cmd(cmd);
2100                 transport_cmd_check_stop_to_fabric(cmd);
2101                 return;
2102         }
2103         /*
2104          * Check for a callback, used by amongst other things
2105          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2106          */
2107         if (cmd->transport_complete_callback) {
2108                 sense_reason_t rc;
2109                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2110                 bool zero_dl = !(cmd->data_length);
2111                 int post_ret = 0;
2112
2113                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2114                 if (!rc && !post_ret) {
2115                         if (caw && zero_dl)
2116                                 goto queue_rsp;
2117
2118                         return;
2119                 } else if (rc) {
2120                         ret = transport_send_check_condition_and_sense(cmd,
2121                                                 rc, 0);
2122                         if (ret == -EAGAIN || ret == -ENOMEM)
2123                                 goto queue_full;
2124
2125                         transport_lun_remove_cmd(cmd);
2126                         transport_cmd_check_stop_to_fabric(cmd);
2127                         return;
2128                 }
2129         }
2130
2131 queue_rsp:
2132         switch (cmd->data_direction) {
2133         case DMA_FROM_DEVICE:
2134                 atomic_long_add(cmd->data_length,
2135                                 &cmd->se_lun->lun_stats.tx_data_octets);
2136                 /*
2137                  * Perform READ_STRIP of PI using software emulation when
2138                  * backend had PI enabled, if the transport will not be
2139                  * performing hardware READ_STRIP offload.
2140                  */
2141                 if (target_read_prot_action(cmd)) {
2142                         ret = transport_send_check_condition_and_sense(cmd,
2143                                                 cmd->pi_err, 0);
2144                         if (ret == -EAGAIN || ret == -ENOMEM)
2145                                 goto queue_full;
2146
2147                         transport_lun_remove_cmd(cmd);
2148                         transport_cmd_check_stop_to_fabric(cmd);
2149                         return;
2150                 }
2151
2152                 trace_target_cmd_complete(cmd);
2153                 ret = cmd->se_tfo->queue_data_in(cmd);
2154                 if (ret == -EAGAIN || ret == -ENOMEM)
2155                         goto queue_full;
2156                 break;
2157         case DMA_TO_DEVICE:
2158                 atomic_long_add(cmd->data_length,
2159                                 &cmd->se_lun->lun_stats.rx_data_octets);
2160                 /*
2161                  * Check if we need to send READ payload for BIDI-COMMAND
2162                  */
2163                 if (cmd->se_cmd_flags & SCF_BIDI) {
2164                         atomic_long_add(cmd->data_length,
2165                                         &cmd->se_lun->lun_stats.tx_data_octets);
2166                         ret = cmd->se_tfo->queue_data_in(cmd);
2167                         if (ret == -EAGAIN || ret == -ENOMEM)
2168                                 goto queue_full;
2169                         break;
2170                 }
2171                 /* Fall through for DMA_TO_DEVICE */
2172         case DMA_NONE:
2173                 trace_target_cmd_complete(cmd);
2174                 ret = cmd->se_tfo->queue_status(cmd);
2175                 if (ret == -EAGAIN || ret == -ENOMEM)
2176                         goto queue_full;
2177                 break;
2178         default:
2179                 break;
2180         }
2181
2182         transport_lun_remove_cmd(cmd);
2183         transport_cmd_check_stop_to_fabric(cmd);
2184         return;
2185
2186 queue_full:
2187         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2188                 " data_direction: %d\n", cmd, cmd->data_direction);
2189         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2190         transport_handle_queue_full(cmd, cmd->se_dev);
2191 }
2192
2193 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2194 {
2195         struct scatterlist *sg;
2196         int count;
2197
2198         for_each_sg(sgl, sg, nents, count)
2199                 __free_page(sg_page(sg));
2200
2201         kfree(sgl);
2202 }
2203
2204 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2205 {
2206         /*
2207          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2208          * emulation, and free + reset pointers if necessary..
2209          */
2210         if (!cmd->t_data_sg_orig)
2211                 return;
2212
2213         kfree(cmd->t_data_sg);
2214         cmd->t_data_sg = cmd->t_data_sg_orig;
2215         cmd->t_data_sg_orig = NULL;
2216         cmd->t_data_nents = cmd->t_data_nents_orig;
2217         cmd->t_data_nents_orig = 0;
2218 }
2219
2220 static inline void transport_free_pages(struct se_cmd *cmd)
2221 {
2222         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2223                 transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2224                 cmd->t_prot_sg = NULL;
2225                 cmd->t_prot_nents = 0;
2226         }
2227
2228         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2229                 /*
2230                  * Release special case READ buffer payload required for
2231                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2232                  */
2233                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2234                         transport_free_sgl(cmd->t_bidi_data_sg,
2235                                            cmd->t_bidi_data_nents);
2236                         cmd->t_bidi_data_sg = NULL;
2237                         cmd->t_bidi_data_nents = 0;
2238                 }
2239                 transport_reset_sgl_orig(cmd);
2240                 return;
2241         }
2242         transport_reset_sgl_orig(cmd);
2243
2244         transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2245         cmd->t_data_sg = NULL;
2246         cmd->t_data_nents = 0;
2247
2248         transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2249         cmd->t_bidi_data_sg = NULL;
2250         cmd->t_bidi_data_nents = 0;
2251 }
2252
2253 /**
2254  * transport_put_cmd - release a reference to a command
2255  * @cmd:       command to release
2256  *
2257  * This routine releases our reference to the command and frees it if possible.
2258  */
2259 static int transport_put_cmd(struct se_cmd *cmd)
2260 {
2261         BUG_ON(!cmd->se_tfo);
2262         /*
2263          * If this cmd has been setup with target_get_sess_cmd(), drop
2264          * the kref and call ->release_cmd() in kref callback.
2265          */
2266         return target_put_sess_cmd(cmd);
2267 }
2268
2269 void *transport_kmap_data_sg(struct se_cmd *cmd)
2270 {
2271         struct scatterlist *sg = cmd->t_data_sg;
2272         struct page **pages;
2273         int i;
2274
2275         /*
2276          * We need to take into account a possible offset here for fabrics like
2277          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2278          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2279          */
2280         if (!cmd->t_data_nents)
2281                 return NULL;
2282
2283         BUG_ON(!sg);
2284         if (cmd->t_data_nents == 1)
2285                 return kmap(sg_page(sg)) + sg->offset;
2286
2287         /* >1 page. use vmap */
2288         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2289         if (!pages)
2290                 return NULL;
2291
2292         /* convert sg[] to pages[] */
2293         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2294                 pages[i] = sg_page(sg);
2295         }
2296
2297         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2298         kfree(pages);
2299         if (!cmd->t_data_vmap)
2300                 return NULL;
2301
2302         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2303 }
2304 EXPORT_SYMBOL(transport_kmap_data_sg);
2305
2306 void transport_kunmap_data_sg(struct se_cmd *cmd)
2307 {
2308         if (!cmd->t_data_nents) {
2309                 return;
2310         } else if (cmd->t_data_nents == 1) {
2311                 kunmap(sg_page(cmd->t_data_sg));
2312                 return;
2313         }
2314
2315         vunmap(cmd->t_data_vmap);
2316         cmd->t_data_vmap = NULL;
2317 }
2318 EXPORT_SYMBOL(transport_kunmap_data_sg);
2319
2320 int
2321 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2322                  bool zero_page)
2323 {
2324         struct scatterlist *sg;
2325         struct page *page;
2326         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2327         unsigned int nent;
2328         int i = 0;
2329
2330         nent = DIV_ROUND_UP(length, PAGE_SIZE);
2331         sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2332         if (!sg)
2333                 return -ENOMEM;
2334
2335         sg_init_table(sg, nent);
2336
2337         while (length) {
2338                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2339                 page = alloc_page(GFP_KERNEL | zero_flag);
2340                 if (!page)
2341                         goto out;
2342
2343                 sg_set_page(&sg[i], page, page_len, 0);
2344                 length -= page_len;
2345                 i++;
2346         }
2347         *sgl = sg;
2348         *nents = nent;
2349         return 0;
2350
2351 out:
2352         while (i > 0) {
2353                 i--;
2354                 __free_page(sg_page(&sg[i]));
2355         }
2356         kfree(sg);
2357         return -ENOMEM;
2358 }
2359
2360 /*
2361  * Allocate any required resources to execute the command.  For writes we
2362  * might not have the payload yet, so notify the fabric via a call to
2363  * ->write_pending instead. Otherwise place it on the execution queue.
2364  */
2365 sense_reason_t
2366 transport_generic_new_cmd(struct se_cmd *cmd)
2367 {
2368         int ret = 0;
2369         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2370
2371         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2372             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2373                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2374                                        cmd->prot_length, true);
2375                 if (ret < 0)
2376                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2377         }
2378
2379         /*
2380          * Determine is the TCM fabric module has already allocated physical
2381          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2382          * beforehand.
2383          */
2384         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2385             cmd->data_length) {
2386
2387                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2388                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2389                         u32 bidi_length;
2390
2391                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2392                                 bidi_length = cmd->t_task_nolb *
2393                                               cmd->se_dev->dev_attrib.block_size;
2394                         else
2395                                 bidi_length = cmd->data_length;
2396
2397                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2398                                                &cmd->t_bidi_data_nents,
2399                                                bidi_length, zero_flag);
2400                         if (ret < 0)
2401                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2402                 }
2403
2404                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2405                                        cmd->data_length, zero_flag);
2406                 if (ret < 0)
2407                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2408         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2409                     cmd->data_length) {
2410                 /*
2411                  * Special case for COMPARE_AND_WRITE with fabrics
2412                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2413                  */
2414                 u32 caw_length = cmd->t_task_nolb *
2415                                  cmd->se_dev->dev_attrib.block_size;
2416
2417                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2418                                        &cmd->t_bidi_data_nents,
2419                                        caw_length, zero_flag);
2420                 if (ret < 0)
2421                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2422         }
2423         /*
2424          * If this command is not a write we can execute it right here,
2425          * for write buffers we need to notify the fabric driver first
2426          * and let it call back once the write buffers are ready.
2427          */
2428         target_add_to_state_list(cmd);
2429         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2430                 target_execute_cmd(cmd);
2431                 return 0;
2432         }
2433         transport_cmd_check_stop(cmd, false, true);
2434
2435         ret = cmd->se_tfo->write_pending(cmd);
2436         if (ret == -EAGAIN || ret == -ENOMEM)
2437                 goto queue_full;
2438
2439         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2440         WARN_ON(ret);
2441
2442         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2443
2444 queue_full:
2445         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2446         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2447         transport_handle_queue_full(cmd, cmd->se_dev);
2448         return 0;
2449 }
2450 EXPORT_SYMBOL(transport_generic_new_cmd);
2451
2452 static void transport_write_pending_qf(struct se_cmd *cmd)
2453 {
2454         int ret;
2455
2456         ret = cmd->se_tfo->write_pending(cmd);
2457         if (ret == -EAGAIN || ret == -ENOMEM) {
2458                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2459                          cmd);
2460                 transport_handle_queue_full(cmd, cmd->se_dev);
2461         }
2462 }
2463
2464 static bool
2465 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2466                            unsigned long *flags);
2467
2468 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2469 {
2470         unsigned long flags;
2471
2472         spin_lock_irqsave(&cmd->t_state_lock, flags);
2473         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2474         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2475 }
2476
2477 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2478 {
2479         int ret = 0;
2480         bool aborted = false, tas = false;
2481
2482         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2483                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2484                         target_wait_free_cmd(cmd, &aborted, &tas);
2485
2486                 if (!aborted || tas)
2487                         ret = transport_put_cmd(cmd);
2488         } else {
2489                 if (wait_for_tasks)
2490                         target_wait_free_cmd(cmd, &aborted, &tas);
2491                 /*
2492                  * Handle WRITE failure case where transport_generic_new_cmd()
2493                  * has already added se_cmd to state_list, but fabric has
2494                  * failed command before I/O submission.
2495                  */
2496                 if (cmd->state_active)
2497                         target_remove_from_state_list(cmd);
2498
2499                 if (cmd->se_lun)
2500                         transport_lun_remove_cmd(cmd);
2501
2502                 if (!aborted || tas)
2503                         ret = transport_put_cmd(cmd);
2504         }
2505         /*
2506          * If the task has been internally aborted due to TMR ABORT_TASK
2507          * or LUN_RESET, target_core_tmr.c is responsible for performing
2508          * the remaining calls to target_put_sess_cmd(), and not the
2509          * callers of this function.
2510          */
2511         if (aborted) {
2512                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2513                 wait_for_completion(&cmd->cmd_wait_comp);
2514                 cmd->se_tfo->release_cmd(cmd);
2515                 ret = 1;
2516         }
2517         return ret;
2518 }
2519 EXPORT_SYMBOL(transport_generic_free_cmd);
2520
2521 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2522  * @se_cmd:     command descriptor to add
2523  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2524  */
2525 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2526 {
2527         struct se_session *se_sess = se_cmd->se_sess;
2528         unsigned long flags;
2529         int ret = 0;
2530
2531         /*
2532          * Add a second kref if the fabric caller is expecting to handle
2533          * fabric acknowledgement that requires two target_put_sess_cmd()
2534          * invocations before se_cmd descriptor release.
2535          */
2536         if (ack_kref) {
2537                 kref_get(&se_cmd->cmd_kref);
2538                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2539         }
2540
2541         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2542         if (se_sess->sess_tearing_down) {
2543                 ret = -ESHUTDOWN;
2544                 goto out;
2545         }
2546         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2547 out:
2548         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2549
2550         if (ret && ack_kref)
2551                 target_put_sess_cmd(se_cmd);
2552
2553         return ret;
2554 }
2555 EXPORT_SYMBOL(target_get_sess_cmd);
2556
2557 static void target_free_cmd_mem(struct se_cmd *cmd)
2558 {
2559         transport_free_pages(cmd);
2560
2561         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2562                 core_tmr_release_req(cmd->se_tmr_req);
2563         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2564                 kfree(cmd->t_task_cdb);
2565 }
2566
2567 static void target_release_cmd_kref(struct kref *kref)
2568 {
2569         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2570         struct se_session *se_sess = se_cmd->se_sess;
2571         unsigned long flags;
2572         bool fabric_stop;
2573
2574         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2575
2576         spin_lock(&se_cmd->t_state_lock);
2577         fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2578                       (se_cmd->transport_state & CMD_T_ABORTED);
2579         spin_unlock(&se_cmd->t_state_lock);
2580
2581         if (se_cmd->cmd_wait_set || fabric_stop) {
2582                 list_del_init(&se_cmd->se_cmd_list);
2583                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2584                 target_free_cmd_mem(se_cmd);
2585                 complete(&se_cmd->cmd_wait_comp);
2586                 return;
2587         }
2588         list_del_init(&se_cmd->se_cmd_list);
2589         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2590
2591         target_free_cmd_mem(se_cmd);
2592         se_cmd->se_tfo->release_cmd(se_cmd);
2593 }
2594
2595 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2596  * @se_cmd:     command descriptor to drop
2597  */
2598 int target_put_sess_cmd(struct se_cmd *se_cmd)
2599 {
2600         struct se_session *se_sess = se_cmd->se_sess;
2601
2602         if (!se_sess) {
2603                 target_free_cmd_mem(se_cmd);
2604                 se_cmd->se_tfo->release_cmd(se_cmd);
2605                 return 1;
2606         }
2607         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2608 }
2609 EXPORT_SYMBOL(target_put_sess_cmd);
2610
2611 /* target_sess_cmd_list_set_waiting - Flag all commands in
2612  *         sess_cmd_list to complete cmd_wait_comp.  Set
2613  *         sess_tearing_down so no more commands are queued.
2614  * @se_sess:    session to flag
2615  */
2616 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2617 {
2618         struct se_cmd *se_cmd;
2619         unsigned long flags;
2620         int rc;
2621
2622         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2623         if (se_sess->sess_tearing_down) {
2624                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2625                 return;
2626         }
2627         se_sess->sess_tearing_down = 1;
2628         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2629
2630         list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list) {
2631                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2632                 if (rc) {
2633                         se_cmd->cmd_wait_set = 1;
2634                         spin_lock(&se_cmd->t_state_lock);
2635                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2636                         spin_unlock(&se_cmd->t_state_lock);
2637                 }
2638         }
2639
2640         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2641 }
2642 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2643
2644 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2645  * @se_sess:    session to wait for active I/O
2646  */
2647 void target_wait_for_sess_cmds(struct se_session *se_sess)
2648 {
2649         struct se_cmd *se_cmd, *tmp_cmd;
2650         unsigned long flags;
2651         bool tas;
2652
2653         list_for_each_entry_safe(se_cmd, tmp_cmd,
2654                                 &se_sess->sess_wait_list, se_cmd_list) {
2655                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2656                         " %d\n", se_cmd, se_cmd->t_state,
2657                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2658
2659                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2660                 tas = (se_cmd->transport_state & CMD_T_TAS);
2661                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2662
2663                 if (!target_put_sess_cmd(se_cmd)) {
2664                         if (tas)
2665                                 target_put_sess_cmd(se_cmd);
2666                 }
2667
2668                 wait_for_completion(&se_cmd->cmd_wait_comp);
2669                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2670                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2671                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2672
2673                 se_cmd->se_tfo->release_cmd(se_cmd);
2674         }
2675
2676         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2677         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2678         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2679
2680 }
2681 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2682
2683 static void target_lun_confirm(struct percpu_ref *ref)
2684 {
2685         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2686
2687         complete(&lun->lun_ref_comp);
2688 }
2689
2690 void transport_clear_lun_ref(struct se_lun *lun)
2691 {
2692         /*
2693          * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2694          * the initial reference and schedule confirm kill to be
2695          * executed after one full RCU grace period has completed.
2696          */
2697         percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2698         /*
2699          * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2700          * to call target_lun_confirm after lun->lun_ref has been marked
2701          * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2702          * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2703          * fails for all new incoming I/O.
2704          */
2705         wait_for_completion(&lun->lun_ref_comp);
2706         /*
2707          * The second completion waits for percpu_ref_put_many() to
2708          * invoke ->release() after lun->lun_ref has switched to
2709          * atomic_t mode, and lun->lun_ref.count has reached zero.
2710          *
2711          * At this point all target-core lun->lun_ref references have
2712          * been dropped via transport_lun_remove_cmd(), and it's safe
2713          * to proceed with the remaining LUN shutdown.
2714          */
2715         wait_for_completion(&lun->lun_shutdown_comp);
2716 }
2717
2718 static bool
2719 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2720                            bool *aborted, bool *tas, unsigned long *flags)
2721         __releases(&cmd->t_state_lock)
2722         __acquires(&cmd->t_state_lock)
2723 {
2724
2725         assert_spin_locked(&cmd->t_state_lock);
2726         WARN_ON_ONCE(!irqs_disabled());
2727
2728         if (fabric_stop)
2729                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2730
2731         if (cmd->transport_state & CMD_T_ABORTED)
2732                 *aborted = true;
2733
2734         if (cmd->transport_state & CMD_T_TAS)
2735                 *tas = true;
2736
2737         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2738             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2739                 return false;
2740
2741         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2742             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2743                 return false;
2744
2745         if (!(cmd->transport_state & CMD_T_ACTIVE))
2746                 return false;
2747
2748         if (fabric_stop && *aborted)
2749                 return false;
2750
2751         cmd->transport_state |= CMD_T_STOP;
2752
2753         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2754                  " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2755                  cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2756
2757         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2758
2759         wait_for_completion(&cmd->t_transport_stop_comp);
2760
2761         spin_lock_irqsave(&cmd->t_state_lock, *flags);
2762         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2763
2764         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2765                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2766
2767         return true;
2768 }
2769
2770 /**
2771  * transport_wait_for_tasks - wait for completion to occur
2772  * @cmd:        command to wait
2773  *
2774  * Called from frontend fabric context to wait for storage engine
2775  * to pause and/or release frontend generated struct se_cmd.
2776  */
2777 bool transport_wait_for_tasks(struct se_cmd *cmd)
2778 {
2779         unsigned long flags;
2780         bool ret, aborted = false, tas = false;
2781
2782         spin_lock_irqsave(&cmd->t_state_lock, flags);
2783         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2784         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2785
2786         return ret;
2787 }
2788 EXPORT_SYMBOL(transport_wait_for_tasks);
2789
2790 struct sense_info {
2791         u8 key;
2792         u8 asc;
2793         u8 ascq;
2794         bool add_sector_info;
2795 };
2796
2797 static const struct sense_info sense_info_table[] = {
2798         [TCM_NO_SENSE] = {
2799                 .key = NOT_READY
2800         },
2801         [TCM_NON_EXISTENT_LUN] = {
2802                 .key = ILLEGAL_REQUEST,
2803                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2804         },
2805         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
2806                 .key = ILLEGAL_REQUEST,
2807                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2808         },
2809         [TCM_SECTOR_COUNT_TOO_MANY] = {
2810                 .key = ILLEGAL_REQUEST,
2811                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2812         },
2813         [TCM_UNKNOWN_MODE_PAGE] = {
2814                 .key = ILLEGAL_REQUEST,
2815                 .asc = 0x24, /* INVALID FIELD IN CDB */
2816         },
2817         [TCM_CHECK_CONDITION_ABORT_CMD] = {
2818                 .key = ABORTED_COMMAND,
2819                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2820                 .ascq = 0x03,
2821         },
2822         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
2823                 .key = ABORTED_COMMAND,
2824                 .asc = 0x0c, /* WRITE ERROR */
2825                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2826         },
2827         [TCM_INVALID_CDB_FIELD] = {
2828                 .key = ILLEGAL_REQUEST,
2829                 .asc = 0x24, /* INVALID FIELD IN CDB */
2830         },
2831         [TCM_INVALID_PARAMETER_LIST] = {
2832                 .key = ILLEGAL_REQUEST,
2833                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2834         },
2835         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2836                 .key = ILLEGAL_REQUEST,
2837                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2838         },
2839         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2840                 .key = ILLEGAL_REQUEST,
2841                 .asc = 0x0c, /* WRITE ERROR */
2842                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2843         },
2844         [TCM_SERVICE_CRC_ERROR] = {
2845                 .key = ABORTED_COMMAND,
2846                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2847                 .ascq = 0x05, /* N/A */
2848         },
2849         [TCM_SNACK_REJECTED] = {
2850                 .key = ABORTED_COMMAND,
2851                 .asc = 0x11, /* READ ERROR */
2852                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2853         },
2854         [TCM_WRITE_PROTECTED] = {
2855                 .key = DATA_PROTECT,
2856                 .asc = 0x27, /* WRITE PROTECTED */
2857         },
2858         [TCM_ADDRESS_OUT_OF_RANGE] = {
2859                 .key = ILLEGAL_REQUEST,
2860                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2861         },
2862         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2863                 .key = UNIT_ATTENTION,
2864         },
2865         [TCM_CHECK_CONDITION_NOT_READY] = {
2866                 .key = NOT_READY,
2867         },
2868         [TCM_MISCOMPARE_VERIFY] = {
2869                 .key = MISCOMPARE,
2870                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2871                 .ascq = 0x00,
2872         },
2873         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2874                 .key = ABORTED_COMMAND,
2875                 .asc = 0x10,
2876                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2877                 .add_sector_info = true,
2878         },
2879         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2880                 .key = ABORTED_COMMAND,
2881                 .asc = 0x10,
2882                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2883                 .add_sector_info = true,
2884         },
2885         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2886                 .key = ABORTED_COMMAND,
2887                 .asc = 0x10,
2888                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2889                 .add_sector_info = true,
2890         },
2891         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
2892                 .key = COPY_ABORTED,
2893                 .asc = 0x0d,
2894                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
2895
2896         },
2897         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2898                 /*
2899                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2900                  * Solaris initiators.  Returning NOT READY instead means the
2901                  * operations will be retried a finite number of times and we
2902                  * can survive intermittent errors.
2903                  */
2904                 .key = NOT_READY,
2905                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2906         },
2907 };
2908
2909 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2910 {
2911         const struct sense_info *si;
2912         u8 *buffer = cmd->sense_buffer;
2913         int r = (__force int)reason;
2914         u8 asc, ascq;
2915         bool desc_format = target_sense_desc_format(cmd->se_dev);
2916
2917         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2918                 si = &sense_info_table[r];
2919         else
2920                 si = &sense_info_table[(__force int)
2921                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2922
2923         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2924                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2925                 WARN_ON_ONCE(asc == 0);
2926         } else if (si->asc == 0) {
2927                 WARN_ON_ONCE(cmd->scsi_asc == 0);
2928                 asc = cmd->scsi_asc;
2929                 ascq = cmd->scsi_ascq;
2930         } else {
2931                 asc = si->asc;
2932                 ascq = si->ascq;
2933         }
2934
2935         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2936         if (si->add_sector_info)
2937                 return scsi_set_sense_information(buffer,
2938                                                   cmd->scsi_sense_length,
2939                                                   cmd->bad_sector);
2940
2941         return 0;
2942 }
2943
2944 int
2945 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2946                 sense_reason_t reason, int from_transport)
2947 {
2948         unsigned long flags;
2949
2950         spin_lock_irqsave(&cmd->t_state_lock, flags);
2951         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2952                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2953                 return 0;
2954         }
2955         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2956         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2957
2958         if (!from_transport) {
2959                 int rc;
2960
2961                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2962                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2963                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2964                 rc = translate_sense_reason(cmd, reason);
2965                 if (rc)
2966                         return rc;
2967         }
2968
2969         trace_target_cmd_complete(cmd);
2970         return cmd->se_tfo->queue_status(cmd);
2971 }
2972 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2973
2974 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2975         __releases(&cmd->t_state_lock)
2976         __acquires(&cmd->t_state_lock)
2977 {
2978         assert_spin_locked(&cmd->t_state_lock);
2979         WARN_ON_ONCE(!irqs_disabled());
2980
2981         if (!(cmd->transport_state & CMD_T_ABORTED))
2982                 return 0;
2983         /*
2984          * If cmd has been aborted but either no status is to be sent or it has
2985          * already been sent, just return
2986          */
2987         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
2988                 if (send_status)
2989                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
2990                 return 1;
2991         }
2992
2993         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
2994                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
2995
2996         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2997         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2998         trace_target_cmd_complete(cmd);
2999
3000         spin_unlock_irq(&cmd->t_state_lock);
3001         cmd->se_tfo->queue_status(cmd);
3002         spin_lock_irq(&cmd->t_state_lock);
3003
3004         return 1;
3005 }
3006
3007 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3008 {
3009         int ret;
3010
3011         spin_lock_irq(&cmd->t_state_lock);
3012         ret = __transport_check_aborted_status(cmd, send_status);
3013         spin_unlock_irq(&cmd->t_state_lock);
3014
3015         return ret;
3016 }
3017 EXPORT_SYMBOL(transport_check_aborted_status);
3018
3019 void transport_send_task_abort(struct se_cmd *cmd)
3020 {
3021         unsigned long flags;
3022
3023         spin_lock_irqsave(&cmd->t_state_lock, flags);
3024         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3025                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3026                 return;
3027         }
3028         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3029
3030         /*
3031          * If there are still expected incoming fabric WRITEs, we wait
3032          * until until they have completed before sending a TASK_ABORTED
3033          * response.  This response with TASK_ABORTED status will be
3034          * queued back to fabric module by transport_check_aborted_status().
3035          */
3036         if (cmd->data_direction == DMA_TO_DEVICE) {
3037                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3038                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3039                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3040                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3041                                 goto send_abort;
3042                         }
3043                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3044                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3045                         return;
3046                 }
3047         }
3048 send_abort:
3049         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3050
3051         transport_lun_remove_cmd(cmd);
3052
3053         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3054                  cmd->t_task_cdb[0], cmd->tag);
3055
3056         trace_target_cmd_complete(cmd);
3057         cmd->se_tfo->queue_status(cmd);
3058 }
3059
3060 static void target_tmr_work(struct work_struct *work)
3061 {
3062         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3063         struct se_device *dev = cmd->se_dev;
3064         struct se_tmr_req *tmr = cmd->se_tmr_req;
3065         unsigned long flags;
3066         int ret;
3067
3068         spin_lock_irqsave(&cmd->t_state_lock, flags);
3069         if (cmd->transport_state & CMD_T_ABORTED) {
3070                 tmr->response = TMR_FUNCTION_REJECTED;
3071                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3072                 goto check_stop;
3073         }
3074         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3075
3076         switch (tmr->function) {
3077         case TMR_ABORT_TASK:
3078                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3079                 break;
3080         case TMR_ABORT_TASK_SET:
3081         case TMR_CLEAR_ACA:
3082         case TMR_CLEAR_TASK_SET:
3083                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3084                 break;
3085         case TMR_LUN_RESET:
3086                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3087                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3088                                          TMR_FUNCTION_REJECTED;
3089                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3090                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3091                                                cmd->orig_fe_lun, 0x29,
3092                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3093                 }
3094                 break;
3095         case TMR_TARGET_WARM_RESET:
3096                 tmr->response = TMR_FUNCTION_REJECTED;
3097                 break;
3098         case TMR_TARGET_COLD_RESET:
3099                 tmr->response = TMR_FUNCTION_REJECTED;
3100                 break;
3101         default:
3102                 pr_err("Uknown TMR function: 0x%02x.\n",
3103                                 tmr->function);
3104                 tmr->response = TMR_FUNCTION_REJECTED;
3105                 break;
3106         }
3107
3108         spin_lock_irqsave(&cmd->t_state_lock, flags);
3109         if (cmd->transport_state & CMD_T_ABORTED) {
3110                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3111                 goto check_stop;
3112         }
3113         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3114
3115         cmd->se_tfo->queue_tm_rsp(cmd);
3116
3117 check_stop:
3118         transport_cmd_check_stop_to_fabric(cmd);
3119 }
3120
3121 int transport_generic_handle_tmr(
3122         struct se_cmd *cmd)
3123 {
3124         unsigned long flags;
3125         bool aborted = false;
3126
3127         spin_lock_irqsave(&cmd->t_state_lock, flags);
3128         if (cmd->transport_state & CMD_T_ABORTED) {
3129                 aborted = true;
3130         } else {
3131                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3132                 cmd->transport_state |= CMD_T_ACTIVE;
3133         }
3134         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3135
3136         if (aborted) {
3137                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3138                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3139                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3140                 transport_cmd_check_stop_to_fabric(cmd);
3141                 return 0;
3142         }
3143
3144         INIT_WORK(&cmd->work, target_tmr_work);
3145         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3146         return 0;
3147 }
3148 EXPORT_SYMBOL(transport_generic_handle_tmr);
3149
3150 bool
3151 target_check_wce(struct se_device *dev)
3152 {
3153         bool wce = false;
3154
3155         if (dev->transport->get_write_cache)
3156                 wce = dev->transport->get_write_cache(dev);
3157         else if (dev->dev_attrib.emulate_write_cache > 0)
3158                 wce = true;
3159
3160         return wce;
3161 }
3162
3163 bool
3164 target_check_fua(struct se_device *dev)
3165 {
3166         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3167 }