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         unsigned long flags;
 310
 311         se_sess->se_tpg = se_tpg;
 312         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 313         /*
 314          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 315          *
 316          * Only set for struct se_session's that will actually be moving I/O.
 317          * eg: *NOT* discovery sessions.
 318          */
 319         if (se_nacl) {
 320                 /*
 321                  *
 322                  * Determine if fabric allows for T10-PI feature bits exposed to
 323                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 324                  *
 325                  * If so, then always save prot_type on a per se_node_acl node
 326                  * basis and re-instate the previous sess_prot_type to avoid
 327                  * disabling PI from below any previously initiator side
 328                  * registered LUNs.
 329                  */
 330                 if (se_nacl->saved_prot_type)
 331                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 332                 else if (tfo->tpg_check_prot_fabric_only)
 333                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 334                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 335                 /*
 336                  * If the fabric module supports an ISID based TransportID,
 337                  * save this value in binary from the fabric I_T Nexus now.
 338                  */
 339                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 340                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 341                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 342                                         &buf[0], PR_REG_ISID_LEN);
 343                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 344                 }
 345
 346                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 347                 /*
 348                  * The se_nacl->nacl_sess pointer will be set to the
 349                  * last active I_T Nexus for each struct se_node_acl.
 350                  */
 351                 se_nacl->nacl_sess = se_sess;
 352
 353                 list_add_tail(&se_sess->sess_acl_list,
 354                               &se_nacl->acl_sess_list);
 355                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 356         }
 357         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 358
 359         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 360                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 361 }
 362 EXPORT_SYMBOL(__transport_register_session);
 363
 364 void transport_register_session(
 365         struct se_portal_group *se_tpg,
 366         struct se_node_acl *se_nacl,
 367         struct se_session *se_sess,
 368         void *fabric_sess_ptr)
 369 {
 370         unsigned long flags;
 371
 372         spin_lock_irqsave(&se_tpg->session_lock, flags);
 373         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 374         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 375 }
 376 EXPORT_SYMBOL(transport_register_session);
 377
 378 static void target_release_session(struct kref *kref)
 379 {
 380         struct se_session *se_sess = container_of(kref,
 381                         struct se_session, sess_kref);
 382         struct se_portal_group *se_tpg = se_sess->se_tpg;
 383
 384         se_tpg->se_tpg_tfo->close_session(se_sess);
 385 }
 386
 387 int target_get_session(struct se_session *se_sess)
 388 {
 389         return kref_get_unless_zero(&se_sess->sess_kref);
 390 }
 391 EXPORT_SYMBOL(target_get_session);
 392
 393 void target_put_session(struct se_session *se_sess)
 394 {
 395         kref_put(&se_sess->sess_kref, target_release_session);
 396 }
 397 EXPORT_SYMBOL(target_put_session);
 398
 399 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 400 {
 401         struct se_session *se_sess;
 402         ssize_t len = 0;
 403
 404         spin_lock_bh(&se_tpg->session_lock);
 405         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 406                 if (!se_sess->se_node_acl)
 407                         continue;
 408                 if (!se_sess->se_node_acl->dynamic_node_acl)
 409                         continue;
 410                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 411                         break;
 412
 413                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 414                                 se_sess->se_node_acl->initiatorname);
 415                 len += 1; /* Include NULL terminator */
 416         }
 417         spin_unlock_bh(&se_tpg->session_lock);
 418
 419         return len;
 420 }
 421 EXPORT_SYMBOL(target_show_dynamic_sessions);
 422
 423 static void target_complete_nacl(struct kref *kref)
 424 {
 425         struct se_node_acl *nacl = container_of(kref,
 426                                 struct se_node_acl, acl_kref);
 427         struct se_portal_group *se_tpg = nacl->se_tpg;
 428
 429         if (!nacl->dynamic_stop) {
 430                 complete(&nacl->acl_free_comp);
 431                 return;
 432         }
 433
 434         mutex_lock(&se_tpg->acl_node_mutex);
 435         list_del_init(&nacl->acl_list);
 436         mutex_unlock(&se_tpg->acl_node_mutex);
 437
 438         core_tpg_wait_for_nacl_pr_ref(nacl);
 439         core_free_device_list_for_node(nacl, se_tpg);
 440         kfree(nacl);
 441 }
 442
 443 void target_put_nacl(struct se_node_acl *nacl)
 444 {
 445         kref_put(&nacl->acl_kref, target_complete_nacl);
 446 }
 447 EXPORT_SYMBOL(target_put_nacl);
 448
 449 void transport_deregister_session_configfs(struct se_session *se_sess)
 450 {
 451         struct se_node_acl *se_nacl;
 452         unsigned long flags;
 453         /*
 454          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 455          */
 456         se_nacl = se_sess->se_node_acl;
 457         if (se_nacl) {
 458                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 459                 if (se_nacl->acl_stop == 0)
 460                         list_del(&se_sess->sess_acl_list);
 461                 /*
 462                  * If the session list is empty, then clear the pointer.
 463                  * Otherwise, set the struct se_session pointer from the tail
 464                  * element of the per struct se_node_acl active session list.
 465                  */
 466                 if (list_empty(&se_nacl->acl_sess_list))
 467                         se_nacl->nacl_sess = NULL;
 468                 else {
 469                         se_nacl->nacl_sess = container_of(
 470                                         se_nacl->acl_sess_list.prev,
 471                                         struct se_session, sess_acl_list);
 472                 }
 473                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 474         }
 475 }
 476 EXPORT_SYMBOL(transport_deregister_session_configfs);
 477
 478 void transport_free_session(struct se_session *se_sess)
 479 {
 480         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 481
 482         /*
 483          * Drop the se_node_acl->nacl_kref obtained from within
 484          * core_tpg_get_initiator_node_acl().
 485          */
 486         if (se_nacl) {
 487                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 488                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 489                 unsigned long flags;
 490
 491                 se_sess->se_node_acl = NULL;
 492
 493                 /*
 494                  * Also determine if we need to drop the extra ->cmd_kref if
 495                  * it had been previously dynamically generated, and
 496                  * the endpoint is not caching dynamic ACLs.
 497                  */
 498                 mutex_lock(&se_tpg->acl_node_mutex);
 499                 if (se_nacl->dynamic_node_acl &&
 500                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 501                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 502                         if (list_empty(&se_nacl->acl_sess_list))
 503                                 se_nacl->dynamic_stop = true;
 504                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 505
 506                         if (se_nacl->dynamic_stop)
 507                                 list_del_init(&se_nacl->acl_list);
 508                 }
 509                 mutex_unlock(&se_tpg->acl_node_mutex);
 510
 511                 if (se_nacl->dynamic_stop)
 512                         target_put_nacl(se_nacl);
 513
 514                 target_put_nacl(se_nacl);
 515         }
 516         if (se_sess->sess_cmd_map) {
 517                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 518                 kvfree(se_sess->sess_cmd_map);
 519         }
 520         kmem_cache_free(se_sess_cache, se_sess);
 521 }
 522 EXPORT_SYMBOL(transport_free_session);
 523
 524 void transport_deregister_session(struct se_session *se_sess)
 525 {
 526         struct se_portal_group *se_tpg = se_sess->se_tpg;
 527         unsigned long flags;
 528
 529         if (!se_tpg) {
 530                 transport_free_session(se_sess);
 531                 return;
 532         }
 533
 534         spin_lock_irqsave(&se_tpg->session_lock, flags);
 535         list_del(&se_sess->sess_list);
 536         se_sess->se_tpg = NULL;
 537         se_sess->fabric_sess_ptr = NULL;
 538         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 539
 540         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 541                 se_tpg->se_tpg_tfo->get_fabric_name());
 542         /*
 543          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 544          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 545          * removal context from within transport_free_session() code.
 546          *
 547          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 548          * to release all remaining generate_node_acl=1 created ACL resources.
 549          */
 550
 551         transport_free_session(se_sess);
 552 }
 553 EXPORT_SYMBOL(transport_deregister_session);
 554
 555 static void target_remove_from_state_list(struct se_cmd *cmd)
 556 {
 557         struct se_device *dev = cmd->se_dev;
 558         unsigned long flags;
 559
 560         if (!dev)
 561                 return;
 562
 563         if (cmd->transport_state & CMD_T_BUSY)
 564                 return;
 565
 566         spin_lock_irqsave(&dev->execute_task_lock, flags);
 567         if (cmd->state_active) {
 568                 list_del(&cmd->state_list);
 569                 cmd->state_active = false;
 570         }
 571         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 572 }
 573
 574 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 575                                     bool write_pending)
 576 {
 577         unsigned long flags;
 578
 579         if (remove_from_lists) {
 580                 target_remove_from_state_list(cmd);
 581
 582                 /*
 583                  * Clear struct se_cmd->se_lun before the handoff to FE.
 584                  */
 585                 cmd->se_lun = NULL;
 586         }
 587
 588         spin_lock_irqsave(&cmd->t_state_lock, flags);
 589         if (write_pending)
 590                 cmd->t_state = TRANSPORT_WRITE_PENDING;
 591
 592         /*
 593          * Determine if frontend context caller is requesting the stopping of
 594          * this command for frontend exceptions.
 595          */
 596         if (cmd->transport_state & CMD_T_STOP) {
 597                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 598                         __func__, __LINE__, cmd->tag);
 599
 600                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 601
 602                 complete_all(&cmd->t_transport_stop_comp);
 603                 return 1;
 604         }
 605
 606         cmd->transport_state &= ~CMD_T_ACTIVE;
 607         if (remove_from_lists) {
 608                 /*
 609                  * Some fabric modules like tcm_loop can release
 610                  * their internally allocated I/O reference now and
 611                  * struct se_cmd now.
 612                  *
 613                  * Fabric modules are expected to return '1' here if the
 614                  * se_cmd being passed is released at this point,
 615                  * or zero if not being released.
 616                  */
 617                 if (cmd->se_tfo->check_stop_free != NULL) {
 618                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 619                         return cmd->se_tfo->check_stop_free(cmd);
 620                 }
 621         }
 622
 623         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 624         return 0;
 625 }
 626
 627 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 628 {
 629         return transport_cmd_check_stop(cmd, true, false);
 630 }
 631
 632 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 633 {
 634         struct se_lun *lun = cmd->se_lun;
 635
 636         if (!lun)
 637                 return;
 638
 639         if (cmpxchg(&cmd->lun_ref_active, true, false))
 640                 percpu_ref_put(&lun->lun_ref);
 641 }
 642
 643 int transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 644 {
 645         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 646         int ret = 0;
 647
 648         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 649                 transport_lun_remove_cmd(cmd);
 650         /*
 651          * Allow the fabric driver to unmap any resources before
 652          * releasing the descriptor via TFO->release_cmd()
 653          */
 654         if (remove)
 655                 cmd->se_tfo->aborted_task(cmd);
 656
 657         if (transport_cmd_check_stop_to_fabric(cmd))
 658                 return 1;
 659         if (remove && ack_kref)
 660                 ret = transport_put_cmd(cmd);
 661
 662         return ret;
 663 }
 664
 665 static void target_complete_failure_work(struct work_struct *work)
 666 {
 667         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 668
 669         transport_generic_request_failure(cmd,
 670                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 671 }
 672
 673 /*
 674  * Used when asking transport to copy Sense Data from the underlying
 675  * Linux/SCSI struct scsi_cmnd
 676  */
 677 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 678 {
 679         struct se_device *dev = cmd->se_dev;
 680
 681         WARN_ON(!cmd->se_lun);
 682
 683         if (!dev)
 684                 return NULL;
 685
 686         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 687                 return NULL;
 688
 689         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 690
 691         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 692                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 693         return cmd->sense_buffer;
 694 }
 695
 696 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 697 {
 698         struct se_device *dev = cmd->se_dev;
 699         int success = scsi_status == GOOD;
 700         unsigned long flags;
 701
 702         cmd->scsi_status = scsi_status;
 703
 704
 705         spin_lock_irqsave(&cmd->t_state_lock, flags);
 706         cmd->transport_state &= ~CMD_T_BUSY;
 707
 708         if (dev && dev->transport->transport_complete) {
 709                 dev->transport->transport_complete(cmd,
 710                                 cmd->t_data_sg,
 711                                 transport_get_sense_buffer(cmd));
 712                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 713                         success = 1;
 714         }
 715
 716         /*
 717          * See if we are waiting to complete for an exception condition.
 718          */
 719         if (cmd->transport_state & CMD_T_REQUEST_STOP) {
 720                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 721                 complete(&cmd->task_stop_comp);
 722                 return;
 723         }
 724
 725         /*
 726          * Check for case where an explicit ABORT_TASK has been received
 727          * and transport_wait_for_tasks() will be waiting for completion..
 728          */
 729         if (cmd->transport_state & CMD_T_ABORTED ||
 730             cmd->transport_state & CMD_T_STOP) {
 731                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 732                 /*
 733                  * If COMPARE_AND_WRITE was stopped by __transport_wait_for_tasks(),
 734                  * release se_device->caw_sem obtained by sbc_compare_and_write()
 735                  * since target_complete_ok_work() or target_complete_failure_work()
 736                  * won't be called to invoke the normal CAW completion callbacks.
 737                  */
 738                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
 739                         up(&dev->caw_sem);
 740                 }
 741                 complete_all(&cmd->t_transport_stop_comp);
 742                 return;
 743         } else if (!success) {
 744                 INIT_WORK(&cmd->work, target_complete_failure_work);
 745         } else {
 746                 INIT_WORK(&cmd->work, target_complete_ok_work);
 747         }
 748
 749         cmd->t_state = TRANSPORT_COMPLETE;
 750         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 751         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 752
 753         queue_work(target_completion_wq, &cmd->work);
 754 }
 755 EXPORT_SYMBOL(target_complete_cmd);
 756
 757 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 758 {
 759         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 760                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 761                         cmd->residual_count += cmd->data_length - length;
 762                 } else {
 763                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 764                         cmd->residual_count = cmd->data_length - length;
 765                 }
 766
 767                 cmd->data_length = length;
 768         }
 769
 770         target_complete_cmd(cmd, scsi_status);
 771 }
 772 EXPORT_SYMBOL(target_complete_cmd_with_length);
 773
 774 static void target_add_to_state_list(struct se_cmd *cmd)
 775 {
 776         struct se_device *dev = cmd->se_dev;
 777         unsigned long flags;
 778
 779         spin_lock_irqsave(&dev->execute_task_lock, flags);
 780         if (!cmd->state_active) {
 781                 list_add_tail(&cmd->state_list, &dev->state_list);
 782                 cmd->state_active = true;
 783         }
 784         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 785 }
 786
 787 /*
 788  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 789  */
 790 static void transport_write_pending_qf(struct se_cmd *cmd);
 791 static void transport_complete_qf(struct se_cmd *cmd);
 792
 793 void target_qf_do_work(struct work_struct *work)
 794 {
 795         struct se_device *dev = container_of(work, struct se_device,
 796                                         qf_work_queue);
 797         LIST_HEAD(qf_cmd_list);
 798         struct se_cmd *cmd, *cmd_tmp;
 799
 800         spin_lock_irq(&dev->qf_cmd_lock);
 801         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 802         spin_unlock_irq(&dev->qf_cmd_lock);
 803
 804         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 805                 list_del(&cmd->se_qf_node);
 806                 atomic_dec_mb(&dev->dev_qf_count);
 807
 808                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 809                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 810                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 811                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 812                         : "UNKNOWN");
 813
 814                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 815                         transport_write_pending_qf(cmd);
 816                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 817                         transport_complete_qf(cmd);
 818         }
 819 }
 820
 821 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 822 {
 823         switch (cmd->data_direction) {
 824         case DMA_NONE:
 825                 return "NONE";
 826         case DMA_FROM_DEVICE:
 827                 return "READ";
 828         case DMA_TO_DEVICE:
 829                 return "WRITE";
 830         case DMA_BIDIRECTIONAL:
 831                 return "BIDI";
 832         default:
 833                 break;
 834         }
 835
 836         return "UNKNOWN";
 837 }
 838
 839 void transport_dump_dev_state(
 840         struct se_device *dev,
 841         char *b,
 842         int *bl)
 843 {
 844         *bl += sprintf(b + *bl, "Status: ");
 845         if (dev->export_count)
 846                 *bl += sprintf(b + *bl, "ACTIVATED");
 847         else
 848                 *bl += sprintf(b + *bl, "DEACTIVATED");
 849
 850         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 851         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 852                 dev->dev_attrib.block_size,
 853                 dev->dev_attrib.hw_max_sectors);
 854         *bl += sprintf(b + *bl, "        ");
 855 }
 856
 857 void transport_dump_vpd_proto_id(
 858         struct t10_vpd *vpd,
 859         unsigned char *p_buf,
 860         int p_buf_len)
 861 {
 862         unsigned char buf[VPD_TMP_BUF_SIZE];
 863         int len;
 864
 865         memset(buf, 0, VPD_TMP_BUF_SIZE);
 866         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 867
 868         switch (vpd->protocol_identifier) {
 869         case 0x00:
 870                 sprintf(buf+len, "Fibre Channel\n");
 871                 break;
 872         case 0x10:
 873                 sprintf(buf+len, "Parallel SCSI\n");
 874                 break;
 875         case 0x20:
 876                 sprintf(buf+len, "SSA\n");
 877                 break;
 878         case 0x30:
 879                 sprintf(buf+len, "IEEE 1394\n");
 880                 break;
 881         case 0x40:
 882                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 883                                 " Protocol\n");
 884                 break;
 885         case 0x50:
 886                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 887                 break;
 888         case 0x60:
 889                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 890                 break;
 891         case 0x70:
 892                 sprintf(buf+len, "Automation/Drive Interface Transport"
 893                                 " Protocol\n");
 894                 break;
 895         case 0x80:
 896                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 897                 break;
 898         default:
 899                 sprintf(buf+len, "Unknown 0x%02x\n",
 900                                 vpd->protocol_identifier);
 901                 break;
 902         }
 903
 904         if (p_buf)
 905                 strncpy(p_buf, buf, p_buf_len);
 906         else
 907                 pr_debug("%s", buf);
 908 }
 909
 910 void
 911 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 912 {
 913         /*
 914          * Check if the Protocol Identifier Valid (PIV) bit is set..
 915          *
 916          * from spc3r23.pdf section 7.5.1
 917          */
 918          if (page_83[1] & 0x80) {
 919                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 920                 vpd->protocol_identifier_set = 1;
 921                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 922         }
 923 }
 924 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 925
 926 int transport_dump_vpd_assoc(
 927         struct t10_vpd *vpd,
 928         unsigned char *p_buf,
 929         int p_buf_len)
 930 {
 931         unsigned char buf[VPD_TMP_BUF_SIZE];
 932         int ret = 0;
 933         int len;
 934
 935         memset(buf, 0, VPD_TMP_BUF_SIZE);
 936         len = sprintf(buf, "T10 VPD Identifier Association: ");
 937
 938         switch (vpd->association) {
 939         case 0x00:
 940                 sprintf(buf+len, "addressed logical unit\n");
 941                 break;
 942         case 0x10:
 943                 sprintf(buf+len, "target port\n");
 944                 break;
 945         case 0x20:
 946                 sprintf(buf+len, "SCSI target device\n");
 947                 break;
 948         default:
 949                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 950                 ret = -EINVAL;
 951                 break;
 952         }
 953
 954         if (p_buf)
 955                 strncpy(p_buf, buf, p_buf_len);
 956         else
 957                 pr_debug("%s", buf);
 958
 959         return ret;
 960 }
 961
 962 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 963 {
 964         /*
 965          * The VPD identification association..
 966          *
 967          * from spc3r23.pdf Section 7.6.3.1 Table 297
 968          */
 969         vpd->association = (page_83[1] & 0x30);
 970         return transport_dump_vpd_assoc(vpd, NULL, 0);
 971 }
 972 EXPORT_SYMBOL(transport_set_vpd_assoc);
 973
 974 int transport_dump_vpd_ident_type(
 975         struct t10_vpd *vpd,
 976         unsigned char *p_buf,
 977         int p_buf_len)
 978 {
 979         unsigned char buf[VPD_TMP_BUF_SIZE];
 980         int ret = 0;
 981         int len;
 982
 983         memset(buf, 0, VPD_TMP_BUF_SIZE);
 984         len = sprintf(buf, "T10 VPD Identifier Type: ");
 985
 986         switch (vpd->device_identifier_type) {
 987         case 0x00:
 988                 sprintf(buf+len, "Vendor specific\n");
 989                 break;
 990         case 0x01:
 991                 sprintf(buf+len, "T10 Vendor ID based\n");
 992                 break;
 993         case 0x02:
 994                 sprintf(buf+len, "EUI-64 based\n");
 995                 break;
 996         case 0x03:
 997                 sprintf(buf+len, "NAA\n");
 998                 break;
 999         case 0x04:
1000                 sprintf(buf+len, "Relative target port identifier\n");
1001                 break;
1002         case 0x08:
1003                 sprintf(buf+len, "SCSI name string\n");
1004                 break;
1005         default:
1006                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1007                                 vpd->device_identifier_type);
1008                 ret = -EINVAL;
1009                 break;
1010         }
1011
1012         if (p_buf) {
1013                 if (p_buf_len < strlen(buf)+1)
1014                         return -EINVAL;
1015                 strncpy(p_buf, buf, p_buf_len);
1016         } else {
1017                 pr_debug("%s", buf);
1018         }
1019
1020         return ret;
1021 }
1022
1023 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1024 {
1025         /*
1026          * The VPD identifier type..
1027          *
1028          * from spc3r23.pdf Section 7.6.3.1 Table 298
1029          */
1030         vpd->device_identifier_type = (page_83[1] & 0x0f);
1031         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1032 }
1033 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1034
1035 int transport_dump_vpd_ident(
1036         struct t10_vpd *vpd,
1037         unsigned char *p_buf,
1038         int p_buf_len)
1039 {
1040         unsigned char buf[VPD_TMP_BUF_SIZE];
1041         int ret = 0;
1042
1043         memset(buf, 0, VPD_TMP_BUF_SIZE);
1044
1045         switch (vpd->device_identifier_code_set) {
1046         case 0x01: /* Binary */
1047                 snprintf(buf, sizeof(buf),
1048                         "T10 VPD Binary Device Identifier: %s\n",
1049                         &vpd->device_identifier[0]);
1050                 break;
1051         case 0x02: /* ASCII */
1052                 snprintf(buf, sizeof(buf),
1053                         "T10 VPD ASCII Device Identifier: %s\n",
1054                         &vpd->device_identifier[0]);
1055                 break;
1056         case 0x03: /* UTF-8 */
1057                 snprintf(buf, sizeof(buf),
1058                         "T10 VPD UTF-8 Device Identifier: %s\n",
1059                         &vpd->device_identifier[0]);
1060                 break;
1061         default:
1062                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1063                         " 0x%02x", vpd->device_identifier_code_set);
1064                 ret = -EINVAL;
1065                 break;
1066         }
1067
1068         if (p_buf)
1069                 strncpy(p_buf, buf, p_buf_len);
1070         else
1071                 pr_debug("%s", buf);
1072
1073         return ret;
1074 }
1075
1076 int
1077 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1078 {
1079         static const char hex_str[] = "0123456789abcdef";
1080         int j = 0, i = 4; /* offset to start of the identifier */
1081
1082         /*
1083          * The VPD Code Set (encoding)
1084          *
1085          * from spc3r23.pdf Section 7.6.3.1 Table 296
1086          */
1087         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1088         switch (vpd->device_identifier_code_set) {
1089         case 0x01: /* Binary */
1090                 vpd->device_identifier[j++] =
1091                                 hex_str[vpd->device_identifier_type];
1092                 while (i < (4 + page_83[3])) {
1093                         vpd->device_identifier[j++] =
1094                                 hex_str[(page_83[i] & 0xf0) >> 4];
1095                         vpd->device_identifier[j++] =
1096                                 hex_str[page_83[i] & 0x0f];
1097                         i++;
1098                 }
1099                 break;
1100         case 0x02: /* ASCII */
1101         case 0x03: /* UTF-8 */
1102                 while (i < (4 + page_83[3]))
1103                         vpd->device_identifier[j++] = page_83[i++];
1104                 break;
1105         default:
1106                 break;
1107         }
1108
1109         return transport_dump_vpd_ident(vpd, NULL, 0);
1110 }
1111 EXPORT_SYMBOL(transport_set_vpd_ident);
1112
1113 static sense_reason_t
1114 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1115                                unsigned int size)
1116 {
1117         u32 mtl;
1118
1119         if (!cmd->se_tfo->max_data_sg_nents)
1120                 return TCM_NO_SENSE;
1121         /*
1122          * Check if fabric enforced maximum SGL entries per I/O descriptor
1123          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1124          * residual_count and reduce original cmd->data_length to maximum
1125          * length based on single PAGE_SIZE entry scatter-lists.
1126          */
1127         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1128         if (cmd->data_length > mtl) {
1129                 /*
1130                  * If an existing CDB overflow is present, calculate new residual
1131                  * based on CDB size minus fabric maximum transfer length.
1132                  *
1133                  * If an existing CDB underflow is present, calculate new residual
1134                  * based on original cmd->data_length minus fabric maximum transfer
1135                  * length.
1136                  *
1137                  * Otherwise, set the underflow residual based on cmd->data_length
1138                  * minus fabric maximum transfer length.
1139                  */
1140                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1141                         cmd->residual_count = (size - mtl);
1142                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1143                         u32 orig_dl = size + cmd->residual_count;
1144                         cmd->residual_count = (orig_dl - mtl);
1145                 } else {
1146                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1147                         cmd->residual_count = (cmd->data_length - mtl);
1148                 }
1149                 cmd->data_length = mtl;
1150                 /*
1151                  * Reset sbc_check_prot() calculated protection payload
1152                  * length based upon the new smaller MTL.
1153                  */
1154                 if (cmd->prot_length) {
1155                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1156                         cmd->prot_length = dev->prot_length * sectors;
1157                 }
1158         }
1159         return TCM_NO_SENSE;
1160 }
1161
1162 sense_reason_t
1163 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1164 {
1165         struct se_device *dev = cmd->se_dev;
1166
1167         if (cmd->unknown_data_length) {
1168                 cmd->data_length = size;
1169         } else if (size != cmd->data_length) {
1170                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1171                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1172                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1173                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1174
1175                 if (cmd->data_direction == DMA_TO_DEVICE) {
1176                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1177                                 pr_err_ratelimited("Rejecting underflow/overflow"
1178                                                    " for WRITE data CDB\n");
1179                                 return TCM_INVALID_CDB_FIELD;
1180                         }
1181                         /*
1182                          * Some fabric drivers like iscsi-target still expect to
1183                          * always reject overflow writes.  Reject this case until
1184                          * full fabric driver level support for overflow writes
1185                          * is introduced tree-wide.
1186                          */
1187                         if (size > cmd->data_length) {
1188                                 pr_err_ratelimited("Rejecting overflow for"
1189                                                    " WRITE control CDB\n");
1190                                 return TCM_INVALID_CDB_FIELD;
1191                         }
1192                 }
1193                 /*
1194                  * Reject READ_* or WRITE_* with overflow/underflow for
1195                  * type SCF_SCSI_DATA_CDB.
1196                  */
1197                 if (dev->dev_attrib.block_size != 512)  {
1198                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1199                                 " CDB on non 512-byte sector setup subsystem"
1200                                 " plugin: %s\n", dev->transport->name);
1201                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1202                         return TCM_INVALID_CDB_FIELD;
1203                 }
1204                 /*
1205                  * For the overflow case keep the existing fabric provided
1206                  * ->data_length.  Otherwise for the underflow case, reset
1207                  * ->data_length to the smaller SCSI expected data transfer
1208                  * length.
1209                  */
1210                 if (size > cmd->data_length) {
1211                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1212                         cmd->residual_count = (size - cmd->data_length);
1213                 } else {
1214                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1215                         cmd->residual_count = (cmd->data_length - size);
1216                         cmd->data_length = size;
1217                 }
1218         }
1219
1220         return target_check_max_data_sg_nents(cmd, dev, size);
1221
1222 }
1223
1224 /*
1225  * Used by fabric modules containing a local struct se_cmd within their
1226  * fabric dependent per I/O descriptor.
1227  *
1228  * Preserves the value of @cmd->tag.
1229  */
1230 void transport_init_se_cmd(
1231         struct se_cmd *cmd,
1232         const struct target_core_fabric_ops *tfo,
1233         struct se_session *se_sess,
1234         u32 data_length,
1235         int data_direction,
1236         int task_attr,
1237         unsigned char *sense_buffer)
1238 {
1239         INIT_LIST_HEAD(&cmd->se_delayed_node);
1240         INIT_LIST_HEAD(&cmd->se_qf_node);
1241         INIT_LIST_HEAD(&cmd->se_cmd_list);
1242         INIT_LIST_HEAD(&cmd->state_list);
1243         init_completion(&cmd->t_transport_stop_comp);
1244         init_completion(&cmd->cmd_wait_comp);
1245         init_completion(&cmd->task_stop_comp);
1246         spin_lock_init(&cmd->t_state_lock);
1247         kref_init(&cmd->cmd_kref);
1248         cmd->transport_state = CMD_T_DEV_ACTIVE;
1249
1250         cmd->se_tfo = tfo;
1251         cmd->se_sess = se_sess;
1252         cmd->data_length = data_length;
1253         cmd->data_direction = data_direction;
1254         cmd->sam_task_attr = task_attr;
1255         cmd->sense_buffer = sense_buffer;
1256
1257         cmd->state_active = false;
1258 }
1259 EXPORT_SYMBOL(transport_init_se_cmd);
1260
1261 static sense_reason_t
1262 transport_check_alloc_task_attr(struct se_cmd *cmd)
1263 {
1264         struct se_device *dev = cmd->se_dev;
1265
1266         /*
1267          * Check if SAM Task Attribute emulation is enabled for this
1268          * struct se_device storage object
1269          */
1270         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1271                 return 0;
1272
1273         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1274                 pr_debug("SAM Task Attribute ACA"
1275                         " emulation is not supported\n");
1276                 return TCM_INVALID_CDB_FIELD;
1277         }
1278
1279         return 0;
1280 }
1281
1282 sense_reason_t
1283 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1284 {
1285         struct se_device *dev = cmd->se_dev;
1286         sense_reason_t ret;
1287
1288         /*
1289          * Ensure that the received CDB is less than the max (252 + 8) bytes
1290          * for VARIABLE_LENGTH_CMD
1291          */
1292         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1293                 pr_err("Received SCSI CDB with command_size: %d that"
1294                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1295                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1296                 return TCM_INVALID_CDB_FIELD;
1297         }
1298         /*
1299          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1300          * allocate the additional extended CDB buffer now..  Otherwise
1301          * setup the pointer from __t_task_cdb to t_task_cdb.
1302          */
1303         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1304                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1305                                                 GFP_KERNEL);
1306                 if (!cmd->t_task_cdb) {
1307                         pr_err("Unable to allocate cmd->t_task_cdb"
1308                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1309                                 scsi_command_size(cdb),
1310                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1311                         return TCM_OUT_OF_RESOURCES;
1312                 }
1313         } else
1314                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1315         /*
1316          * Copy the original CDB into cmd->
1317          */
1318         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1319
1320         trace_target_sequencer_start(cmd);
1321
1322         ret = dev->transport->parse_cdb(cmd);
1323         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1324                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1325                                     cmd->se_tfo->get_fabric_name(),
1326                                     cmd->se_sess->se_node_acl->initiatorname,
1327                                     cmd->t_task_cdb[0]);
1328         if (ret)
1329                 return ret;
1330
1331         ret = transport_check_alloc_task_attr(cmd);
1332         if (ret)
1333                 return ret;
1334
1335         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1336         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1337         return 0;
1338 }
1339 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1340
1341 /*
1342  * Used by fabric module frontends to queue tasks directly.
1343  * Many only be used from process context only
1344  */
1345 int transport_handle_cdb_direct(
1346         struct se_cmd *cmd)
1347 {
1348         sense_reason_t ret;
1349
1350         if (!cmd->se_lun) {
1351                 dump_stack();
1352                 pr_err("cmd->se_lun is NULL\n");
1353                 return -EINVAL;
1354         }
1355         if (in_interrupt()) {
1356                 dump_stack();
1357                 pr_err("transport_generic_handle_cdb cannot be called"
1358                                 " from interrupt context\n");
1359                 return -EINVAL;
1360         }
1361         /*
1362          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1363          * outstanding descriptors are handled correctly during shutdown via
1364          * transport_wait_for_tasks()
1365          *
1366          * Also, we don't take cmd->t_state_lock here as we only expect
1367          * this to be called for initial descriptor submission.
1368          */
1369         cmd->t_state = TRANSPORT_NEW_CMD;
1370         cmd->transport_state |= CMD_T_ACTIVE;
1371
1372         /*
1373          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1374          * so follow TRANSPORT_NEW_CMD processing thread context usage
1375          * and call transport_generic_request_failure() if necessary..
1376          */
1377         ret = transport_generic_new_cmd(cmd);
1378         if (ret)
1379                 transport_generic_request_failure(cmd, ret);
1380         return 0;
1381 }
1382 EXPORT_SYMBOL(transport_handle_cdb_direct);
1383
1384 sense_reason_t
1385 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1386                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1387 {
1388         if (!sgl || !sgl_count)
1389                 return 0;
1390
1391         /*
1392          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1393          * scatterlists already have been set to follow what the fabric
1394          * passes for the original expected data transfer length.
1395          */
1396         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1397                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1398                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1399                 return TCM_INVALID_CDB_FIELD;
1400         }
1401
1402         cmd->t_data_sg = sgl;
1403         cmd->t_data_nents = sgl_count;
1404         cmd->t_bidi_data_sg = sgl_bidi;
1405         cmd->t_bidi_data_nents = sgl_bidi_count;
1406
1407         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1408         return 0;
1409 }
1410
1411 /*
1412  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1413  *                       se_cmd + use pre-allocated SGL memory.
1414  *
1415  * @se_cmd: command descriptor to submit
1416  * @se_sess: associated se_sess for endpoint
1417  * @cdb: pointer to SCSI CDB
1418  * @sense: pointer to SCSI sense buffer
1419  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1420  * @data_length: fabric expected data transfer length
1421  * @task_addr: SAM task attribute
1422  * @data_dir: DMA data direction
1423  * @flags: flags for command submission from target_sc_flags_tables
1424  * @sgl: struct scatterlist memory for unidirectional mapping
1425  * @sgl_count: scatterlist count for unidirectional mapping
1426  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1427  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1428  * @sgl_prot: struct scatterlist memory protection information
1429  * @sgl_prot_count: scatterlist count for protection information
1430  *
1431  * Task tags are supported if the caller has set @se_cmd->tag.
1432  *
1433  * Returns non zero to signal active I/O shutdown failure.  All other
1434  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1435  * but still return zero here.
1436  *
1437  * This may only be called from process context, and also currently
1438  * assumes internal allocation of fabric payload buffer by target-core.
1439  */
1440 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1441                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1442                 u32 data_length, int task_attr, int data_dir, int flags,
1443                 struct scatterlist *sgl, u32 sgl_count,
1444                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1445                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1446 {
1447         struct se_portal_group *se_tpg;
1448         sense_reason_t rc;
1449         int ret;
1450
1451         se_tpg = se_sess->se_tpg;
1452         BUG_ON(!se_tpg);
1453         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1454         BUG_ON(in_interrupt());
1455         /*
1456          * Initialize se_cmd for target operation.  From this point
1457          * exceptions are handled by sending exception status via
1458          * target_core_fabric_ops->queue_status() callback
1459          */
1460         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1461                                 data_length, data_dir, task_attr, sense);
1462         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1463                 se_cmd->unknown_data_length = 1;
1464         /*
1465          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1466          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1467          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1468          * kref_put() to happen during fabric packet acknowledgement.
1469          */
1470         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1471         if (ret)
1472                 return ret;
1473         /*
1474          * Signal bidirectional data payloads to target-core
1475          */
1476         if (flags & TARGET_SCF_BIDI_OP)
1477                 se_cmd->se_cmd_flags |= SCF_BIDI;
1478         /*
1479          * Locate se_lun pointer and attach it to struct se_cmd
1480          */
1481         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1482         if (rc) {
1483                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1484                 target_put_sess_cmd(se_cmd);
1485                 return 0;
1486         }
1487
1488         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1489         if (rc != 0) {
1490                 transport_generic_request_failure(se_cmd, rc);
1491                 return 0;
1492         }
1493
1494         /*
1495          * Save pointers for SGLs containing protection information,
1496          * if present.
1497          */
1498         if (sgl_prot_count) {
1499                 se_cmd->t_prot_sg = sgl_prot;
1500                 se_cmd->t_prot_nents = sgl_prot_count;
1501                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1502         }
1503
1504         /*
1505          * When a non zero sgl_count has been passed perform SGL passthrough
1506          * mapping for pre-allocated fabric memory instead of having target
1507          * core perform an internal SGL allocation..
1508          */
1509         if (sgl_count != 0) {
1510                 BUG_ON(!sgl);
1511
1512                 /*
1513                  * A work-around for tcm_loop as some userspace code via
1514                  * scsi-generic do not memset their associated read buffers,
1515                  * so go ahead and do that here for type non-data CDBs.  Also
1516                  * note that this is currently guaranteed to be a single SGL
1517                  * for this case by target core in target_setup_cmd_from_cdb()
1518                  * -> transport_generic_cmd_sequencer().
1519                  */
1520                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1521                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1522                         unsigned char *buf = NULL;
1523
1524                         if (sgl)
1525                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1526
1527                         if (buf) {
1528                                 memset(buf, 0, sgl->length);
1529                                 kunmap(sg_page(sgl));
1530                         }
1531                 }
1532
1533                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1534                                 sgl_bidi, sgl_bidi_count);
1535                 if (rc != 0) {
1536                         transport_generic_request_failure(se_cmd, rc);
1537                         return 0;
1538                 }
1539         }
1540
1541         /*
1542          * Check if we need to delay processing because of ALUA
1543          * Active/NonOptimized primary access state..
1544          */
1545         core_alua_check_nonop_delay(se_cmd);
1546
1547         transport_handle_cdb_direct(se_cmd);
1548         return 0;
1549 }
1550 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1551
1552 /*
1553  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1554  *
1555  * @se_cmd: command descriptor to submit
1556  * @se_sess: associated se_sess for endpoint
1557  * @cdb: pointer to SCSI CDB
1558  * @sense: pointer to SCSI sense buffer
1559  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1560  * @data_length: fabric expected data transfer length
1561  * @task_addr: SAM task attribute
1562  * @data_dir: DMA data direction
1563  * @flags: flags for command submission from target_sc_flags_tables
1564  *
1565  * Task tags are supported if the caller has set @se_cmd->tag.
1566  *
1567  * Returns non zero to signal active I/O shutdown failure.  All other
1568  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1569  * but still return zero here.
1570  *
1571  * This may only be called from process context, and also currently
1572  * assumes internal allocation of fabric payload buffer by target-core.
1573  *
1574  * It also assumes interal target core SGL memory allocation.
1575  */
1576 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1577                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1578                 u32 data_length, int task_attr, int data_dir, int flags)
1579 {
1580         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1581                         unpacked_lun, data_length, task_attr, data_dir,
1582                         flags, NULL, 0, NULL, 0, NULL, 0);
1583 }
1584 EXPORT_SYMBOL(target_submit_cmd);
1585
1586 static void target_complete_tmr_failure(struct work_struct *work)
1587 {
1588         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1589
1590         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1591         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1592
1593         transport_cmd_check_stop_to_fabric(se_cmd);
1594 }
1595
1596 /**
1597  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1598  *                     for TMR CDBs
1599  *
1600  * @se_cmd: command descriptor to submit
1601  * @se_sess: associated se_sess for endpoint
1602  * @sense: pointer to SCSI sense buffer
1603  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1604  * @fabric_context: fabric context for TMR req
1605  * @tm_type: Type of TM request
1606  * @gfp: gfp type for caller
1607  * @tag: referenced task tag for TMR_ABORT_TASK
1608  * @flags: submit cmd flags
1609  *
1610  * Callable from all contexts.
1611  **/
1612
1613 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1614                 unsigned char *sense, u64 unpacked_lun,
1615                 void *fabric_tmr_ptr, unsigned char tm_type,
1616                 gfp_t gfp, unsigned int tag, int flags)
1617 {
1618         struct se_portal_group *se_tpg;
1619         int ret;
1620
1621         se_tpg = se_sess->se_tpg;
1622         BUG_ON(!se_tpg);
1623
1624         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1625                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1626         /*
1627          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1628          * allocation failure.
1629          */
1630         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1631         if (ret < 0)
1632                 return -ENOMEM;
1633
1634         if (tm_type == TMR_ABORT_TASK)
1635                 se_cmd->se_tmr_req->ref_task_tag = tag;
1636
1637         /* See target_submit_cmd for commentary */
1638         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1639         if (ret) {
1640                 core_tmr_release_req(se_cmd->se_tmr_req);
1641                 return ret;
1642         }
1643
1644         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1645         if (ret) {
1646                 /*
1647                  * For callback during failure handling, push this work off
1648                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1649                  */
1650                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1651                 schedule_work(&se_cmd->work);
1652                 return 0;
1653         }
1654         transport_generic_handle_tmr(se_cmd);
1655         return 0;
1656 }
1657 EXPORT_SYMBOL(target_submit_tmr);
1658
1659 /*
1660  * If the cmd is active, request it to be stopped and sleep until it
1661  * has completed.
1662  */
1663 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1664         __releases(&cmd->t_state_lock)
1665         __acquires(&cmd->t_state_lock)
1666 {
1667         bool was_active = false;
1668
1669         if (cmd->transport_state & CMD_T_BUSY) {
1670                 cmd->transport_state |= CMD_T_REQUEST_STOP;
1671                 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1672
1673                 pr_debug("cmd %p waiting to complete\n", cmd);
1674                 wait_for_completion(&cmd->task_stop_comp);
1675                 pr_debug("cmd %p stopped successfully\n", cmd);
1676
1677                 spin_lock_irqsave(&cmd->t_state_lock, *flags);
1678                 cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1679                 cmd->transport_state &= ~CMD_T_BUSY;
1680                 was_active = true;
1681         }
1682
1683         return was_active;
1684 }
1685
1686 /*
1687  * Handle SAM-esque emulation for generic transport request failures.
1688  */
1689 void transport_generic_request_failure(struct se_cmd *cmd,
1690                 sense_reason_t sense_reason)
1691 {
1692         int ret = 0, post_ret = 0;
1693
1694         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1695                 " CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1696         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1697                 cmd->se_tfo->get_cmd_state(cmd),
1698                 cmd->t_state, sense_reason);
1699         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1700                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1701                 (cmd->transport_state & CMD_T_STOP) != 0,
1702                 (cmd->transport_state & CMD_T_SENT) != 0);
1703
1704         /*
1705          * For SAM Task Attribute emulation for failed struct se_cmd
1706          */
1707         transport_complete_task_attr(cmd);
1708         /*
1709          * Handle special case for COMPARE_AND_WRITE failure, where the
1710          * callback is expected to drop the per device ->caw_sem.
1711          */
1712         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1713              cmd->transport_complete_callback)
1714                 cmd->transport_complete_callback(cmd, false, &post_ret);
1715
1716         switch (sense_reason) {
1717         case TCM_NON_EXISTENT_LUN:
1718         case TCM_UNSUPPORTED_SCSI_OPCODE:
1719         case TCM_INVALID_CDB_FIELD:
1720         case TCM_INVALID_PARAMETER_LIST:
1721         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1722         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1723         case TCM_UNKNOWN_MODE_PAGE:
1724         case TCM_WRITE_PROTECTED:
1725         case TCM_ADDRESS_OUT_OF_RANGE:
1726         case TCM_CHECK_CONDITION_ABORT_CMD:
1727         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1728         case TCM_CHECK_CONDITION_NOT_READY:
1729         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1730         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1731         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1732         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1733                 break;
1734         case TCM_OUT_OF_RESOURCES:
1735                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1736                 break;
1737         case TCM_RESERVATION_CONFLICT:
1738                 /*
1739                  * No SENSE Data payload for this case, set SCSI Status
1740                  * and queue the response to $FABRIC_MOD.
1741                  *
1742                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1743                  */
1744                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1745                 /*
1746                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1747                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1748                  * CONFLICT STATUS.
1749                  *
1750                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1751                  */
1752                 if (cmd->se_sess &&
1753                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1754                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1755                                                cmd->orig_fe_lun, 0x2C,
1756                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1757                 }
1758                 trace_target_cmd_complete(cmd);
1759                 ret = cmd->se_tfo->queue_status(cmd);
1760                 if (ret == -EAGAIN || ret == -ENOMEM)
1761                         goto queue_full;
1762                 goto check_stop;
1763         default:
1764                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1765                         cmd->t_task_cdb[0], sense_reason);
1766                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1767                 break;
1768         }
1769
1770         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1771         if (ret == -EAGAIN || ret == -ENOMEM)
1772                 goto queue_full;
1773
1774 check_stop:
1775         transport_lun_remove_cmd(cmd);
1776         transport_cmd_check_stop_to_fabric(cmd);
1777         return;
1778
1779 queue_full:
1780         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1781         transport_handle_queue_full(cmd, cmd->se_dev);
1782 }
1783 EXPORT_SYMBOL(transport_generic_request_failure);
1784
1785 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1786 {
1787         sense_reason_t ret;
1788
1789         if (!cmd->execute_cmd) {
1790                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1791                 goto err;
1792         }
1793         if (do_checks) {
1794                 /*
1795                  * Check for an existing UNIT ATTENTION condition after
1796                  * target_handle_task_attr() has done SAM task attr
1797                  * checking, and possibly have already defered execution
1798                  * out to target_restart_delayed_cmds() context.
1799                  */
1800                 ret = target_scsi3_ua_check(cmd);
1801                 if (ret)
1802                         goto err;
1803
1804                 ret = target_alua_state_check(cmd);
1805                 if (ret)
1806                         goto err;
1807
1808                 ret = target_check_reservation(cmd);
1809                 if (ret) {
1810                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1811                         goto err;
1812                 }
1813         }
1814
1815         ret = cmd->execute_cmd(cmd);
1816         if (!ret)
1817                 return;
1818 err:
1819         spin_lock_irq(&cmd->t_state_lock);
1820         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1821         spin_unlock_irq(&cmd->t_state_lock);
1822
1823         transport_generic_request_failure(cmd, ret);
1824 }
1825
1826 static int target_write_prot_action(struct se_cmd *cmd)
1827 {
1828         u32 sectors;
1829         /*
1830          * Perform WRITE_INSERT of PI using software emulation when backend
1831          * device has PI enabled, if the transport has not already generated
1832          * PI using hardware WRITE_INSERT offload.
1833          */
1834         switch (cmd->prot_op) {
1835         case TARGET_PROT_DOUT_INSERT:
1836                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1837                         sbc_dif_generate(cmd);
1838                 break;
1839         case TARGET_PROT_DOUT_STRIP:
1840                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1841                         break;
1842
1843                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1844                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1845                                              sectors, 0, cmd->t_prot_sg, 0);
1846                 if (unlikely(cmd->pi_err)) {
1847                         spin_lock_irq(&cmd->t_state_lock);
1848                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1849                         spin_unlock_irq(&cmd->t_state_lock);
1850                         transport_generic_request_failure(cmd, cmd->pi_err);
1851                         return -1;
1852                 }
1853                 break;
1854         default:
1855                 break;
1856         }
1857
1858         return 0;
1859 }
1860
1861 static bool target_handle_task_attr(struct se_cmd *cmd)
1862 {
1863         struct se_device *dev = cmd->se_dev;
1864
1865         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1866                 return false;
1867
1868         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1869
1870         /*
1871          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1872          * to allow the passed struct se_cmd list of tasks to the front of the list.
1873          */
1874         switch (cmd->sam_task_attr) {
1875         case TCM_HEAD_TAG:
1876                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1877                          cmd->t_task_cdb[0]);
1878                 return false;
1879         case TCM_ORDERED_TAG:
1880                 atomic_inc_mb(&dev->dev_ordered_sync);
1881
1882                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1883                          cmd->t_task_cdb[0]);
1884
1885                 /*
1886                  * Execute an ORDERED command if no other older commands
1887                  * exist that need to be completed first.
1888                  */
1889                 if (!atomic_read(&dev->simple_cmds))
1890                         return false;
1891                 break;
1892         default:
1893                 /*
1894                  * For SIMPLE and UNTAGGED Task Attribute commands
1895                  */
1896                 atomic_inc_mb(&dev->simple_cmds);
1897                 break;
1898         }
1899
1900         if (atomic_read(&dev->dev_ordered_sync) == 0)
1901                 return false;
1902
1903         spin_lock(&dev->delayed_cmd_lock);
1904         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1905         spin_unlock(&dev->delayed_cmd_lock);
1906
1907         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1908                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1909         return true;
1910 }
1911
1912 static int __transport_check_aborted_status(struct se_cmd *, int);
1913
1914 void target_execute_cmd(struct se_cmd *cmd)
1915 {
1916         /*
1917          * Determine if frontend context caller is requesting the stopping of
1918          * this command for frontend exceptions.
1919          *
1920          * If the received CDB has aleady been aborted stop processing it here.
1921          */
1922         spin_lock_irq(&cmd->t_state_lock);
1923         if (__transport_check_aborted_status(cmd, 1)) {
1924                 spin_unlock_irq(&cmd->t_state_lock);
1925                 return;
1926         }
1927         if (cmd->transport_state & CMD_T_STOP) {
1928                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1929                         __func__, __LINE__, cmd->tag);
1930
1931                 spin_unlock_irq(&cmd->t_state_lock);
1932                 complete_all(&cmd->t_transport_stop_comp);
1933                 return;
1934         }
1935
1936         cmd->t_state = TRANSPORT_PROCESSING;
1937         cmd->transport_state &= ~CMD_T_PRE_EXECUTE;
1938         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1939         spin_unlock_irq(&cmd->t_state_lock);
1940
1941         if (target_write_prot_action(cmd))
1942                 return;
1943
1944         if (target_handle_task_attr(cmd)) {
1945                 spin_lock_irq(&cmd->t_state_lock);
1946                 cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1947                 spin_unlock_irq(&cmd->t_state_lock);
1948                 return;
1949         }
1950
1951         __target_execute_cmd(cmd, true);
1952 }
1953 EXPORT_SYMBOL(target_execute_cmd);
1954
1955 /*
1956  * Process all commands up to the last received ORDERED task attribute which
1957  * requires another blocking boundary
1958  */
1959 static void target_restart_delayed_cmds(struct se_device *dev)
1960 {
1961         for (;;) {
1962                 struct se_cmd *cmd;
1963
1964                 spin_lock(&dev->delayed_cmd_lock);
1965                 if (list_empty(&dev->delayed_cmd_list)) {
1966                         spin_unlock(&dev->delayed_cmd_lock);
1967                         break;
1968                 }
1969
1970                 cmd = list_entry(dev->delayed_cmd_list.next,
1971                                  struct se_cmd, se_delayed_node);
1972                 list_del(&cmd->se_delayed_node);
1973                 spin_unlock(&dev->delayed_cmd_lock);
1974
1975                 cmd->transport_state |= CMD_T_SENT;
1976
1977                 __target_execute_cmd(cmd, true);
1978
1979                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1980                         break;
1981         }
1982 }
1983
1984 /*
1985  * Called from I/O completion to determine which dormant/delayed
1986  * and ordered cmds need to have their tasks added to the execution queue.
1987  */
1988 static void transport_complete_task_attr(struct se_cmd *cmd)
1989 {
1990         struct se_device *dev = cmd->se_dev;
1991
1992         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1993                 return;
1994
1995         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
1996                 goto restart;
1997
1998         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1999                 atomic_dec_mb(&dev->simple_cmds);
2000                 dev->dev_cur_ordered_id++;
2001                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for SIMPLE\n",
2002                          dev->dev_cur_ordered_id);
2003         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2004                 dev->dev_cur_ordered_id++;
2005                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2006                          dev->dev_cur_ordered_id);
2007         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2008                 atomic_dec_mb(&dev->dev_ordered_sync);
2009
2010                 dev->dev_cur_ordered_id++;
2011                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2012                          dev->dev_cur_ordered_id);
2013         }
2014         cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2015
2016 restart:
2017         target_restart_delayed_cmds(dev);
2018 }
2019
2020 static void transport_complete_qf(struct se_cmd *cmd)
2021 {
2022         int ret = 0;
2023
2024         transport_complete_task_attr(cmd);
2025
2026         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2027                 trace_target_cmd_complete(cmd);
2028                 ret = cmd->se_tfo->queue_status(cmd);
2029                 goto out;
2030         }
2031
2032         switch (cmd->data_direction) {
2033         case DMA_FROM_DEVICE:
2034                 trace_target_cmd_complete(cmd);
2035                 ret = cmd->se_tfo->queue_data_in(cmd);
2036                 break;
2037         case DMA_TO_DEVICE:
2038                 if (cmd->se_cmd_flags & SCF_BIDI) {
2039                         ret = cmd->se_tfo->queue_data_in(cmd);
2040                         break;
2041                 }
2042                 /* Fall through for DMA_TO_DEVICE */
2043         case DMA_NONE:
2044                 trace_target_cmd_complete(cmd);
2045                 ret = cmd->se_tfo->queue_status(cmd);
2046                 break;
2047         default:
2048                 break;
2049         }
2050
2051 out:
2052         if (ret < 0) {
2053                 transport_handle_queue_full(cmd, cmd->se_dev);
2054                 return;
2055         }
2056         transport_lun_remove_cmd(cmd);
2057         transport_cmd_check_stop_to_fabric(cmd);
2058 }
2059
2060 static void transport_handle_queue_full(
2061         struct se_cmd *cmd,
2062         struct se_device *dev)
2063 {
2064         spin_lock_irq(&dev->qf_cmd_lock);
2065         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2066         atomic_inc_mb(&dev->dev_qf_count);
2067         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2068
2069         schedule_work(&cmd->se_dev->qf_work_queue);
2070 }
2071
2072 static bool target_read_prot_action(struct se_cmd *cmd)
2073 {
2074         switch (cmd->prot_op) {
2075         case TARGET_PROT_DIN_STRIP:
2076                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2077                         u32 sectors = cmd->data_length >>
2078                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2079
2080                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2081                                                      sectors, 0, cmd->t_prot_sg,
2082                                                      0);
2083                         if (cmd->pi_err)
2084                                 return true;
2085                 }
2086                 break;
2087         case TARGET_PROT_DIN_INSERT:
2088                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2089                         break;
2090
2091                 sbc_dif_generate(cmd);
2092                 break;
2093         default:
2094                 break;
2095         }
2096
2097         return false;
2098 }
2099
2100 static void target_complete_ok_work(struct work_struct *work)
2101 {
2102         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2103         int ret;
2104
2105         /*
2106          * Check if we need to move delayed/dormant tasks from cmds on the
2107          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2108          * Attribute.
2109          */
2110         transport_complete_task_attr(cmd);
2111
2112         /*
2113          * Check to schedule QUEUE_FULL work, or execute an existing
2114          * cmd->transport_qf_callback()
2115          */
2116         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2117                 schedule_work(&cmd->se_dev->qf_work_queue);
2118
2119         /*
2120          * Check if we need to send a sense buffer from
2121          * the struct se_cmd in question.
2122          */
2123         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2124                 WARN_ON(!cmd->scsi_status);
2125                 ret = transport_send_check_condition_and_sense(
2126                                         cmd, 0, 1);
2127                 if (ret == -EAGAIN || ret == -ENOMEM)
2128                         goto queue_full;
2129
2130                 transport_lun_remove_cmd(cmd);
2131                 transport_cmd_check_stop_to_fabric(cmd);
2132                 return;
2133         }
2134         /*
2135          * Check for a callback, used by amongst other things
2136          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2137          */
2138         if (cmd->transport_complete_callback) {
2139                 sense_reason_t rc;
2140                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2141                 bool zero_dl = !(cmd->data_length);
2142                 int post_ret = 0;
2143
2144                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2145                 if (!rc && !post_ret) {
2146                         if (caw && zero_dl)
2147                                 goto queue_rsp;
2148
2149                         return;
2150                 } else if (rc) {
2151                         ret = transport_send_check_condition_and_sense(cmd,
2152                                                 rc, 0);
2153                         if (ret == -EAGAIN || ret == -ENOMEM)
2154                                 goto queue_full;
2155
2156                         transport_lun_remove_cmd(cmd);
2157                         transport_cmd_check_stop_to_fabric(cmd);
2158                         return;
2159                 }
2160         }
2161
2162 queue_rsp:
2163         switch (cmd->data_direction) {
2164         case DMA_FROM_DEVICE:
2165                 atomic_long_add(cmd->data_length,
2166                                 &cmd->se_lun->lun_stats.tx_data_octets);
2167                 /*
2168                  * Perform READ_STRIP of PI using software emulation when
2169                  * backend had PI enabled, if the transport will not be
2170                  * performing hardware READ_STRIP offload.
2171                  */
2172                 if (target_read_prot_action(cmd)) {
2173                         ret = transport_send_check_condition_and_sense(cmd,
2174                                                 cmd->pi_err, 0);
2175                         if (ret == -EAGAIN || ret == -ENOMEM)
2176                                 goto queue_full;
2177
2178                         transport_lun_remove_cmd(cmd);
2179                         transport_cmd_check_stop_to_fabric(cmd);
2180                         return;
2181                 }
2182
2183                 trace_target_cmd_complete(cmd);
2184                 ret = cmd->se_tfo->queue_data_in(cmd);
2185                 if (ret == -EAGAIN || ret == -ENOMEM)
2186                         goto queue_full;
2187                 break;
2188         case DMA_TO_DEVICE:
2189                 atomic_long_add(cmd->data_length,
2190                                 &cmd->se_lun->lun_stats.rx_data_octets);
2191                 /*
2192                  * Check if we need to send READ payload for BIDI-COMMAND
2193                  */
2194                 if (cmd->se_cmd_flags & SCF_BIDI) {
2195                         atomic_long_add(cmd->data_length,
2196                                         &cmd->se_lun->lun_stats.tx_data_octets);
2197                         ret = cmd->se_tfo->queue_data_in(cmd);
2198                         if (ret == -EAGAIN || ret == -ENOMEM)
2199                                 goto queue_full;
2200                         break;
2201                 }
2202                 /* Fall through for DMA_TO_DEVICE */
2203         case DMA_NONE:
2204                 trace_target_cmd_complete(cmd);
2205                 ret = cmd->se_tfo->queue_status(cmd);
2206                 if (ret == -EAGAIN || ret == -ENOMEM)
2207                         goto queue_full;
2208                 break;
2209         default:
2210                 break;
2211         }
2212
2213         transport_lun_remove_cmd(cmd);
2214         transport_cmd_check_stop_to_fabric(cmd);
2215         return;
2216
2217 queue_full:
2218         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2219                 " data_direction: %d\n", cmd, cmd->data_direction);
2220         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2221         transport_handle_queue_full(cmd, cmd->se_dev);
2222 }
2223
2224 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2225 {
2226         struct scatterlist *sg;
2227         int count;
2228
2229         for_each_sg(sgl, sg, nents, count)
2230                 __free_page(sg_page(sg));
2231
2232         kfree(sgl);
2233 }
2234
2235 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2236 {
2237         /*
2238          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2239          * emulation, and free + reset pointers if necessary..
2240          */
2241         if (!cmd->t_data_sg_orig)
2242                 return;
2243
2244         kfree(cmd->t_data_sg);
2245         cmd->t_data_sg = cmd->t_data_sg_orig;
2246         cmd->t_data_sg_orig = NULL;
2247         cmd->t_data_nents = cmd->t_data_nents_orig;
2248         cmd->t_data_nents_orig = 0;
2249 }
2250
2251 static inline void transport_free_pages(struct se_cmd *cmd)
2252 {
2253         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2254                 transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2255                 cmd->t_prot_sg = NULL;
2256                 cmd->t_prot_nents = 0;
2257         }
2258
2259         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2260                 /*
2261                  * Release special case READ buffer payload required for
2262                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2263                  */
2264                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2265                         transport_free_sgl(cmd->t_bidi_data_sg,
2266                                            cmd->t_bidi_data_nents);
2267                         cmd->t_bidi_data_sg = NULL;
2268                         cmd->t_bidi_data_nents = 0;
2269                 }
2270                 transport_reset_sgl_orig(cmd);
2271                 return;
2272         }
2273         transport_reset_sgl_orig(cmd);
2274
2275         transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2276         cmd->t_data_sg = NULL;
2277         cmd->t_data_nents = 0;
2278
2279         transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2280         cmd->t_bidi_data_sg = NULL;
2281         cmd->t_bidi_data_nents = 0;
2282 }
2283
2284 /**
2285  * transport_put_cmd - release a reference to a command
2286  * @cmd:       command to release
2287  *
2288  * This routine releases our reference to the command and frees it if possible.
2289  */
2290 static int transport_put_cmd(struct se_cmd *cmd)
2291 {
2292         BUG_ON(!cmd->se_tfo);
2293         /*
2294          * If this cmd has been setup with target_get_sess_cmd(), drop
2295          * the kref and call ->release_cmd() in kref callback.
2296          */
2297         return target_put_sess_cmd(cmd);
2298 }
2299
2300 void *transport_kmap_data_sg(struct se_cmd *cmd)
2301 {
2302         struct scatterlist *sg = cmd->t_data_sg;
2303         struct page **pages;
2304         int i;
2305
2306         /*
2307          * We need to take into account a possible offset here for fabrics like
2308          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2309          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2310          */
2311         if (!cmd->t_data_nents)
2312                 return NULL;
2313
2314         BUG_ON(!sg);
2315         if (cmd->t_data_nents == 1)
2316                 return kmap(sg_page(sg)) + sg->offset;
2317
2318         /* >1 page. use vmap */
2319         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2320         if (!pages)
2321                 return NULL;
2322
2323         /* convert sg[] to pages[] */
2324         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2325                 pages[i] = sg_page(sg);
2326         }
2327
2328         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2329         kfree(pages);
2330         if (!cmd->t_data_vmap)
2331                 return NULL;
2332
2333         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2334 }
2335 EXPORT_SYMBOL(transport_kmap_data_sg);
2336
2337 void transport_kunmap_data_sg(struct se_cmd *cmd)
2338 {
2339         if (!cmd->t_data_nents) {
2340                 return;
2341         } else if (cmd->t_data_nents == 1) {
2342                 kunmap(sg_page(cmd->t_data_sg));
2343                 return;
2344         }
2345
2346         vunmap(cmd->t_data_vmap);
2347         cmd->t_data_vmap = NULL;
2348 }
2349 EXPORT_SYMBOL(transport_kunmap_data_sg);
2350
2351 int
2352 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2353                  bool zero_page)
2354 {
2355         struct scatterlist *sg;
2356         struct page *page;
2357         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2358         unsigned int nent;
2359         int i = 0;
2360
2361         nent = DIV_ROUND_UP(length, PAGE_SIZE);
2362         sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2363         if (!sg)
2364                 return -ENOMEM;
2365
2366         sg_init_table(sg, nent);
2367
2368         while (length) {
2369                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2370                 page = alloc_page(GFP_KERNEL | zero_flag);
2371                 if (!page)
2372                         goto out;
2373
2374                 sg_set_page(&sg[i], page, page_len, 0);
2375                 length -= page_len;
2376                 i++;
2377         }
2378         *sgl = sg;
2379         *nents = nent;
2380         return 0;
2381
2382 out:
2383         while (i > 0) {
2384                 i--;
2385                 __free_page(sg_page(&sg[i]));
2386         }
2387         kfree(sg);
2388         return -ENOMEM;
2389 }
2390
2391 /*
2392  * Allocate any required resources to execute the command.  For writes we
2393  * might not have the payload yet, so notify the fabric via a call to
2394  * ->write_pending instead. Otherwise place it on the execution queue.
2395  */
2396 sense_reason_t
2397 transport_generic_new_cmd(struct se_cmd *cmd)
2398 {
2399         int ret = 0;
2400         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2401
2402         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2403             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2404                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2405                                        cmd->prot_length, true);
2406                 if (ret < 0)
2407                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2408         }
2409
2410         /*
2411          * Determine is the TCM fabric module has already allocated physical
2412          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2413          * beforehand.
2414          */
2415         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2416             cmd->data_length) {
2417
2418                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2419                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2420                         u32 bidi_length;
2421
2422                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2423                                 bidi_length = cmd->t_task_nolb *
2424                                               cmd->se_dev->dev_attrib.block_size;
2425                         else
2426                                 bidi_length = cmd->data_length;
2427
2428                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2429                                                &cmd->t_bidi_data_nents,
2430                                                bidi_length, zero_flag);
2431                         if (ret < 0)
2432                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2433                 }
2434
2435                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2436                                        cmd->data_length, zero_flag);
2437                 if (ret < 0)
2438                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2439         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2440                     cmd->data_length) {
2441                 /*
2442                  * Special case for COMPARE_AND_WRITE with fabrics
2443                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2444                  */
2445                 u32 caw_length = cmd->t_task_nolb *
2446                                  cmd->se_dev->dev_attrib.block_size;
2447
2448                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2449                                        &cmd->t_bidi_data_nents,
2450                                        caw_length, zero_flag);
2451                 if (ret < 0)
2452                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2453         }
2454         /*
2455          * If this command is not a write we can execute it right here,
2456          * for write buffers we need to notify the fabric driver first
2457          * and let it call back once the write buffers are ready.
2458          */
2459         target_add_to_state_list(cmd);
2460         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2461                 target_execute_cmd(cmd);
2462                 return 0;
2463         }
2464         transport_cmd_check_stop(cmd, false, true);
2465
2466         ret = cmd->se_tfo->write_pending(cmd);
2467         if (ret == -EAGAIN || ret == -ENOMEM)
2468                 goto queue_full;
2469
2470         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2471         WARN_ON(ret);
2472
2473         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2474
2475 queue_full:
2476         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2477         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2478         transport_handle_queue_full(cmd, cmd->se_dev);
2479         return 0;
2480 }
2481 EXPORT_SYMBOL(transport_generic_new_cmd);
2482
2483 static void transport_write_pending_qf(struct se_cmd *cmd)
2484 {
2485         int ret;
2486
2487         ret = cmd->se_tfo->write_pending(cmd);
2488         if (ret == -EAGAIN || ret == -ENOMEM) {
2489                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2490                          cmd);
2491                 transport_handle_queue_full(cmd, cmd->se_dev);
2492         }
2493 }
2494
2495 static bool
2496 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2497                            unsigned long *flags);
2498
2499 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2500 {
2501         unsigned long flags;
2502
2503         spin_lock_irqsave(&cmd->t_state_lock, flags);
2504         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2505         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2506 }
2507
2508 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2509 {
2510         int ret = 0;
2511         bool aborted = false, tas = false;
2512
2513         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2514                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2515                         target_wait_free_cmd(cmd, &aborted, &tas);
2516
2517                 if (!aborted || tas)
2518                         ret = transport_put_cmd(cmd);
2519         } else {
2520                 if (wait_for_tasks)
2521                         target_wait_free_cmd(cmd, &aborted, &tas);
2522                 /*
2523                  * Handle WRITE failure case where transport_generic_new_cmd()
2524                  * has already added se_cmd to state_list, but fabric has
2525                  * failed command before I/O submission.
2526                  */
2527                 if (cmd->state_active)
2528                         target_remove_from_state_list(cmd);
2529
2530                 if (cmd->se_lun)
2531                         transport_lun_remove_cmd(cmd);
2532
2533                 if (!aborted || tas)
2534                         ret = transport_put_cmd(cmd);
2535         }
2536         /*
2537          * If the task has been internally aborted due to TMR ABORT_TASK
2538          * or LUN_RESET, target_core_tmr.c is responsible for performing
2539          * the remaining calls to target_put_sess_cmd(), and not the
2540          * callers of this function.
2541          */
2542         if (aborted) {
2543                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2544                 wait_for_completion(&cmd->cmd_wait_comp);
2545                 cmd->se_tfo->release_cmd(cmd);
2546                 ret = 1;
2547         }
2548         return ret;
2549 }
2550 EXPORT_SYMBOL(transport_generic_free_cmd);
2551
2552 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2553  * @se_cmd:     command descriptor to add
2554  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2555  */
2556 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2557 {
2558         struct se_session *se_sess = se_cmd->se_sess;
2559         unsigned long flags;
2560         int ret = 0;
2561
2562         /*
2563          * Add a second kref if the fabric caller is expecting to handle
2564          * fabric acknowledgement that requires two target_put_sess_cmd()
2565          * invocations before se_cmd descriptor release.
2566          */
2567         if (ack_kref) {
2568                 kref_get(&se_cmd->cmd_kref);
2569                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2570         }
2571
2572         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2573         if (se_sess->sess_tearing_down) {
2574                 ret = -ESHUTDOWN;
2575                 goto out;
2576         }
2577         se_cmd->transport_state |= CMD_T_PRE_EXECUTE;
2578         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2579 out:
2580         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2581
2582         if (ret && ack_kref)
2583                 target_put_sess_cmd(se_cmd);
2584
2585         return ret;
2586 }
2587 EXPORT_SYMBOL(target_get_sess_cmd);
2588
2589 static void target_free_cmd_mem(struct se_cmd *cmd)
2590 {
2591         transport_free_pages(cmd);
2592
2593         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2594                 core_tmr_release_req(cmd->se_tmr_req);
2595         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2596                 kfree(cmd->t_task_cdb);
2597 }
2598
2599 static void target_release_cmd_kref(struct kref *kref)
2600 {
2601         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2602         struct se_session *se_sess = se_cmd->se_sess;
2603         unsigned long flags;
2604         bool fabric_stop;
2605
2606         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2607
2608         spin_lock(&se_cmd->t_state_lock);
2609         fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2610                       (se_cmd->transport_state & CMD_T_ABORTED);
2611         spin_unlock(&se_cmd->t_state_lock);
2612
2613         if (se_cmd->cmd_wait_set || fabric_stop) {
2614                 list_del_init(&se_cmd->se_cmd_list);
2615                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2616                 target_free_cmd_mem(se_cmd);
2617                 complete(&se_cmd->cmd_wait_comp);
2618                 return;
2619         }
2620         list_del_init(&se_cmd->se_cmd_list);
2621         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2622
2623         target_free_cmd_mem(se_cmd);
2624         se_cmd->se_tfo->release_cmd(se_cmd);
2625 }
2626
2627 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2628  * @se_cmd:     command descriptor to drop
2629  */
2630 int target_put_sess_cmd(struct se_cmd *se_cmd)
2631 {
2632         struct se_session *se_sess = se_cmd->se_sess;
2633
2634         if (!se_sess) {
2635                 target_free_cmd_mem(se_cmd);
2636                 se_cmd->se_tfo->release_cmd(se_cmd);
2637                 return 1;
2638         }
2639         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2640 }
2641 EXPORT_SYMBOL(target_put_sess_cmd);
2642
2643 /* target_sess_cmd_list_set_waiting - Flag all commands in
2644  *         sess_cmd_list to complete cmd_wait_comp.  Set
2645  *         sess_tearing_down so no more commands are queued.
2646  * @se_sess:    session to flag
2647  */
2648 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2649 {
2650         struct se_cmd *se_cmd;
2651         unsigned long flags;
2652         int rc;
2653
2654         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2655         if (se_sess->sess_tearing_down) {
2656                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2657                 return;
2658         }
2659         se_sess->sess_tearing_down = 1;
2660         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2661
2662         list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list) {
2663                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2664                 if (rc) {
2665                         se_cmd->cmd_wait_set = 1;
2666                         spin_lock(&se_cmd->t_state_lock);
2667                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2668                         spin_unlock(&se_cmd->t_state_lock);
2669                 }
2670         }
2671
2672         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2673 }
2674 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2675
2676 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2677  * @se_sess:    session to wait for active I/O
2678  */
2679 void target_wait_for_sess_cmds(struct se_session *se_sess)
2680 {
2681         struct se_cmd *se_cmd, *tmp_cmd;
2682         unsigned long flags;
2683         bool tas;
2684
2685         list_for_each_entry_safe(se_cmd, tmp_cmd,
2686                                 &se_sess->sess_wait_list, se_cmd_list) {
2687                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2688                         " %d\n", se_cmd, se_cmd->t_state,
2689                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2690
2691                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2692                 tas = (se_cmd->transport_state & CMD_T_TAS);
2693                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2694
2695                 if (!target_put_sess_cmd(se_cmd)) {
2696                         if (tas)
2697                                 target_put_sess_cmd(se_cmd);
2698                 }
2699
2700                 wait_for_completion(&se_cmd->cmd_wait_comp);
2701                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2702                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2703                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2704
2705                 se_cmd->se_tfo->release_cmd(se_cmd);
2706         }
2707
2708         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2709         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2710         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2711
2712 }
2713 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2714
2715 static void target_lun_confirm(struct percpu_ref *ref)
2716 {
2717         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2718
2719         complete(&lun->lun_ref_comp);
2720 }
2721
2722 void transport_clear_lun_ref(struct se_lun *lun)
2723 {
2724         /*
2725          * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2726          * the initial reference and schedule confirm kill to be
2727          * executed after one full RCU grace period has completed.
2728          */
2729         percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2730         /*
2731          * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2732          * to call target_lun_confirm after lun->lun_ref has been marked
2733          * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2734          * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2735          * fails for all new incoming I/O.
2736          */
2737         wait_for_completion(&lun->lun_ref_comp);
2738         /*
2739          * The second completion waits for percpu_ref_put_many() to
2740          * invoke ->release() after lun->lun_ref has switched to
2741          * atomic_t mode, and lun->lun_ref.count has reached zero.
2742          *
2743          * At this point all target-core lun->lun_ref references have
2744          * been dropped via transport_lun_remove_cmd(), and it's safe
2745          * to proceed with the remaining LUN shutdown.
2746          */
2747         wait_for_completion(&lun->lun_shutdown_comp);
2748 }
2749
2750 static bool
2751 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2752                            bool *aborted, bool *tas, unsigned long *flags)
2753         __releases(&cmd->t_state_lock)
2754         __acquires(&cmd->t_state_lock)
2755 {
2756
2757         assert_spin_locked(&cmd->t_state_lock);
2758         WARN_ON_ONCE(!irqs_disabled());
2759
2760         if (fabric_stop)
2761                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2762
2763         if (cmd->transport_state & CMD_T_ABORTED)
2764                 *aborted = true;
2765
2766         if (cmd->transport_state & CMD_T_TAS)
2767                 *tas = true;
2768
2769         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2770             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2771                 return false;
2772
2773         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2774             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2775                 return false;
2776
2777         if (!(cmd->transport_state & CMD_T_ACTIVE))
2778                 return false;
2779
2780         if (fabric_stop && *aborted)
2781                 return false;
2782
2783         cmd->transport_state |= CMD_T_STOP;
2784
2785         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2786                  " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2787                  cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2788
2789         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2790
2791         wait_for_completion(&cmd->t_transport_stop_comp);
2792
2793         spin_lock_irqsave(&cmd->t_state_lock, *flags);
2794         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2795
2796         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2797                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2798
2799         return true;
2800 }
2801
2802 /**
2803  * transport_wait_for_tasks - wait for completion to occur
2804  * @cmd:        command to wait
2805  *
2806  * Called from frontend fabric context to wait for storage engine
2807  * to pause and/or release frontend generated struct se_cmd.
2808  */
2809 bool transport_wait_for_tasks(struct se_cmd *cmd)
2810 {
2811         unsigned long flags;
2812         bool ret, aborted = false, tas = false;
2813
2814         spin_lock_irqsave(&cmd->t_state_lock, flags);
2815         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2816         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2817
2818         return ret;
2819 }
2820 EXPORT_SYMBOL(transport_wait_for_tasks);
2821
2822 struct sense_info {
2823         u8 key;
2824         u8 asc;
2825         u8 ascq;
2826         bool add_sector_info;
2827 };
2828
2829 static const struct sense_info sense_info_table[] = {
2830         [TCM_NO_SENSE] = {
2831                 .key = NOT_READY
2832         },
2833         [TCM_NON_EXISTENT_LUN] = {
2834                 .key = ILLEGAL_REQUEST,
2835                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2836         },
2837         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
2838                 .key = ILLEGAL_REQUEST,
2839                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2840         },
2841         [TCM_SECTOR_COUNT_TOO_MANY] = {
2842                 .key = ILLEGAL_REQUEST,
2843                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2844         },
2845         [TCM_UNKNOWN_MODE_PAGE] = {
2846                 .key = ILLEGAL_REQUEST,
2847                 .asc = 0x24, /* INVALID FIELD IN CDB */
2848         },
2849         [TCM_CHECK_CONDITION_ABORT_CMD] = {
2850                 .key = ABORTED_COMMAND,
2851                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2852                 .ascq = 0x03,
2853         },
2854         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
2855                 .key = ABORTED_COMMAND,
2856                 .asc = 0x0c, /* WRITE ERROR */
2857                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2858         },
2859         [TCM_INVALID_CDB_FIELD] = {
2860                 .key = ILLEGAL_REQUEST,
2861                 .asc = 0x24, /* INVALID FIELD IN CDB */
2862         },
2863         [TCM_INVALID_PARAMETER_LIST] = {
2864                 .key = ILLEGAL_REQUEST,
2865                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2866         },
2867         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2868                 .key = ILLEGAL_REQUEST,
2869                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2870         },
2871         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2872                 .key = ILLEGAL_REQUEST,
2873                 .asc = 0x0c, /* WRITE ERROR */
2874                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2875         },
2876         [TCM_SERVICE_CRC_ERROR] = {
2877                 .key = ABORTED_COMMAND,
2878                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2879                 .ascq = 0x05, /* N/A */
2880         },
2881         [TCM_SNACK_REJECTED] = {
2882                 .key = ABORTED_COMMAND,
2883                 .asc = 0x11, /* READ ERROR */
2884                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2885         },
2886         [TCM_WRITE_PROTECTED] = {
2887                 .key = DATA_PROTECT,
2888                 .asc = 0x27, /* WRITE PROTECTED */
2889         },
2890         [TCM_ADDRESS_OUT_OF_RANGE] = {
2891                 .key = ILLEGAL_REQUEST,
2892                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2893         },
2894         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2895                 .key = UNIT_ATTENTION,
2896         },
2897         [TCM_CHECK_CONDITION_NOT_READY] = {
2898                 .key = NOT_READY,
2899         },
2900         [TCM_MISCOMPARE_VERIFY] = {
2901                 .key = MISCOMPARE,
2902                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2903                 .ascq = 0x00,
2904         },
2905         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2906                 .key = ABORTED_COMMAND,
2907                 .asc = 0x10,
2908                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2909                 .add_sector_info = true,
2910         },
2911         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2912                 .key = ABORTED_COMMAND,
2913                 .asc = 0x10,
2914                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2915                 .add_sector_info = true,
2916         },
2917         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2918                 .key = ABORTED_COMMAND,
2919                 .asc = 0x10,
2920                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2921                 .add_sector_info = true,
2922         },
2923         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
2924                 .key = COPY_ABORTED,
2925                 .asc = 0x0d,
2926                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
2927
2928         },
2929         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2930                 /*
2931                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2932                  * Solaris initiators.  Returning NOT READY instead means the
2933                  * operations will be retried a finite number of times and we
2934                  * can survive intermittent errors.
2935                  */
2936                 .key = NOT_READY,
2937                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2938         },
2939 };
2940
2941 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2942 {
2943         const struct sense_info *si;
2944         u8 *buffer = cmd->sense_buffer;
2945         int r = (__force int)reason;
2946         u8 asc, ascq;
2947         bool desc_format = target_sense_desc_format(cmd->se_dev);
2948
2949         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2950                 si = &sense_info_table[r];
2951         else
2952                 si = &sense_info_table[(__force int)
2953                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2954
2955         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2956                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2957                 WARN_ON_ONCE(asc == 0);
2958         } else if (si->asc == 0) {
2959                 WARN_ON_ONCE(cmd->scsi_asc == 0);
2960                 asc = cmd->scsi_asc;
2961                 ascq = cmd->scsi_ascq;
2962         } else {
2963                 asc = si->asc;
2964                 ascq = si->ascq;
2965         }
2966
2967         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2968         if (si->add_sector_info)
2969                 return scsi_set_sense_information(buffer,
2970                                                   cmd->scsi_sense_length,
2971                                                   cmd->bad_sector);
2972
2973         return 0;
2974 }
2975
2976 int
2977 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2978                 sense_reason_t reason, int from_transport)
2979 {
2980         unsigned long flags;
2981
2982         spin_lock_irqsave(&cmd->t_state_lock, flags);
2983         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2984                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2985                 return 0;
2986         }
2987         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2988         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2989
2990         if (!from_transport) {
2991                 int rc;
2992
2993                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2994                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2995                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2996                 rc = translate_sense_reason(cmd, reason);
2997                 if (rc)
2998                         return rc;
2999         }
3000
3001         trace_target_cmd_complete(cmd);
3002         return cmd->se_tfo->queue_status(cmd);
3003 }
3004 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3005
3006 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3007         __releases(&cmd->t_state_lock)
3008         __acquires(&cmd->t_state_lock)
3009 {
3010         assert_spin_locked(&cmd->t_state_lock);
3011         WARN_ON_ONCE(!irqs_disabled());
3012
3013         if (!(cmd->transport_state & CMD_T_ABORTED))
3014                 return 0;
3015         /*
3016          * If cmd has been aborted but either no status is to be sent or it has
3017          * already been sent, just return
3018          */
3019         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3020                 if (send_status)
3021                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3022                 return 1;
3023         }
3024
3025         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3026                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3027
3028         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3029         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3030         trace_target_cmd_complete(cmd);
3031
3032         spin_unlock_irq(&cmd->t_state_lock);
3033         cmd->se_tfo->queue_status(cmd);
3034         spin_lock_irq(&cmd->t_state_lock);
3035
3036         return 1;
3037 }
3038
3039 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3040 {
3041         int ret;
3042
3043         spin_lock_irq(&cmd->t_state_lock);
3044         ret = __transport_check_aborted_status(cmd, send_status);
3045         spin_unlock_irq(&cmd->t_state_lock);
3046
3047         return ret;
3048 }
3049 EXPORT_SYMBOL(transport_check_aborted_status);
3050
3051 void transport_send_task_abort(struct se_cmd *cmd)
3052 {
3053         unsigned long flags;
3054
3055         spin_lock_irqsave(&cmd->t_state_lock, flags);
3056         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3057                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3058                 return;
3059         }
3060         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3061
3062         /*
3063          * If there are still expected incoming fabric WRITEs, we wait
3064          * until until they have completed before sending a TASK_ABORTED
3065          * response.  This response with TASK_ABORTED status will be
3066          * queued back to fabric module by transport_check_aborted_status().
3067          */
3068         if (cmd->data_direction == DMA_TO_DEVICE) {
3069                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3070                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3071                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3072                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3073                                 goto send_abort;
3074                         }
3075                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3076                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3077                         return;
3078                 }
3079         }
3080 send_abort:
3081         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3082
3083         transport_lun_remove_cmd(cmd);
3084
3085         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3086                  cmd->t_task_cdb[0], cmd->tag);
3087
3088         trace_target_cmd_complete(cmd);
3089         cmd->se_tfo->queue_status(cmd);
3090 }
3091
3092 static void target_tmr_work(struct work_struct *work)
3093 {
3094         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3095         struct se_device *dev = cmd->se_dev;
3096         struct se_tmr_req *tmr = cmd->se_tmr_req;
3097         unsigned long flags;
3098         int ret;
3099
3100         spin_lock_irqsave(&cmd->t_state_lock, flags);
3101         if (cmd->transport_state & CMD_T_ABORTED) {
3102                 tmr->response = TMR_FUNCTION_REJECTED;
3103                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3104                 goto check_stop;
3105         }
3106         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3107
3108         switch (tmr->function) {
3109         case TMR_ABORT_TASK:
3110                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3111                 break;
3112         case TMR_ABORT_TASK_SET:
3113         case TMR_CLEAR_ACA:
3114         case TMR_CLEAR_TASK_SET:
3115                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3116                 break;
3117         case TMR_LUN_RESET:
3118                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3119                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3120                                          TMR_FUNCTION_REJECTED;
3121                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3122                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3123                                                cmd->orig_fe_lun, 0x29,
3124                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3125                 }
3126                 break;
3127         case TMR_TARGET_WARM_RESET:
3128                 tmr->response = TMR_FUNCTION_REJECTED;
3129                 break;
3130         case TMR_TARGET_COLD_RESET:
3131                 tmr->response = TMR_FUNCTION_REJECTED;
3132                 break;
3133         default:
3134                 pr_err("Uknown TMR function: 0x%02x.\n",
3135                                 tmr->function);
3136                 tmr->response = TMR_FUNCTION_REJECTED;
3137                 break;
3138         }
3139
3140         spin_lock_irqsave(&cmd->t_state_lock, flags);
3141         if (cmd->transport_state & CMD_T_ABORTED) {
3142                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3143                 goto check_stop;
3144         }
3145         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3146
3147         cmd->se_tfo->queue_tm_rsp(cmd);
3148
3149 check_stop:
3150         transport_cmd_check_stop_to_fabric(cmd);
3151 }
3152
3153 int transport_generic_handle_tmr(
3154         struct se_cmd *cmd)
3155 {
3156         unsigned long flags;
3157         bool aborted = false;
3158
3159         spin_lock_irqsave(&cmd->t_state_lock, flags);
3160         if (cmd->transport_state & CMD_T_ABORTED) {
3161                 aborted = true;
3162         } else {
3163                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3164                 cmd->transport_state |= CMD_T_ACTIVE;
3165         }
3166         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3167
3168         if (aborted) {
3169                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3170                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3171                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3172                 transport_cmd_check_stop_to_fabric(cmd);
3173                 return 0;
3174         }
3175
3176         INIT_WORK(&cmd->work, target_tmr_work);
3177         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3178         return 0;
3179 }
3180 EXPORT_SYMBOL(transport_generic_handle_tmr);
3181
3182 bool
3183 target_check_wce(struct se_device *dev)
3184 {
3185         bool wce = false;
3186
3187         if (dev->transport->get_write_cache)
3188                 wce = dev->transport->get_write_cache(dev);
3189         else if (dev->dev_attrib.emulate_write_cache > 0)
3190                 wce = true;
3191
3192         return wce;
3193 }
3194
3195 bool
3196 target_check_fua(struct se_device *dev)
3197 {
3198         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3199 }