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 int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
  68 static void transport_handle_queue_full(struct se_cmd *cmd,
  69                 struct se_device *dev, int err, bool write_pending);
  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         se_sess->sup_prot_ops = sup_prot_ops;
 243
 244         return se_sess;
 245 }
 246 EXPORT_SYMBOL(transport_init_session);
 247
 248 int transport_alloc_session_tags(struct se_session *se_sess,
 249                                  unsigned int tag_num, unsigned int tag_size)
 250 {
 251         int rc;
 252
 253         se_sess->sess_cmd_map = kcalloc(tag_size, tag_num,
 254                                         GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);
 255         if (!se_sess->sess_cmd_map) {
 256                 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
 257                 if (!se_sess->sess_cmd_map) {
 258                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 259                         return -ENOMEM;
 260                 }
 261         }
 262
 263         rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
 264         if (rc < 0) {
 265                 pr_err("Unable to init se_sess->sess_tag_pool,"
 266                         " tag_num: %u\n", tag_num);
 267                 kvfree(se_sess->sess_cmd_map);
 268                 se_sess->sess_cmd_map = NULL;
 269                 return -ENOMEM;
 270         }
 271
 272         return 0;
 273 }
 274 EXPORT_SYMBOL(transport_alloc_session_tags);
 275
 276 struct se_session *transport_init_session_tags(unsigned int tag_num,
 277                                                unsigned int tag_size,
 278                                                enum target_prot_op sup_prot_ops)
 279 {
 280         struct se_session *se_sess;
 281         int rc;
 282
 283         if (tag_num != 0 && !tag_size) {
 284                 pr_err("init_session_tags called with percpu-ida tag_num:"
 285                        " %u, but zero tag_size\n", tag_num);
 286                 return ERR_PTR(-EINVAL);
 287         }
 288         if (!tag_num && tag_size) {
 289                 pr_err("init_session_tags called with percpu-ida tag_size:"
 290                        " %u, but zero tag_num\n", tag_size);
 291                 return ERR_PTR(-EINVAL);
 292         }
 293
 294         se_sess = transport_init_session(sup_prot_ops);
 295         if (IS_ERR(se_sess))
 296                 return se_sess;
 297
 298         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 299         if (rc < 0) {
 300                 transport_free_session(se_sess);
 301                 return ERR_PTR(-ENOMEM);
 302         }
 303
 304         return se_sess;
 305 }
 306 EXPORT_SYMBOL(transport_init_session_tags);
 307
 308 /*
 309  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 310  */
 311 void __transport_register_session(
 312         struct se_portal_group *se_tpg,
 313         struct se_node_acl *se_nacl,
 314         struct se_session *se_sess,
 315         void *fabric_sess_ptr)
 316 {
 317         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 318         unsigned char buf[PR_REG_ISID_LEN];
 319
 320         se_sess->se_tpg = se_tpg;
 321         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 322         /*
 323          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 324          *
 325          * Only set for struct se_session's that will actually be moving I/O.
 326          * eg: *NOT* discovery sessions.
 327          */
 328         if (se_nacl) {
 329                 /*
 330                  *
 331                  * Determine if fabric allows for T10-PI feature bits exposed to
 332                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 333                  *
 334                  * If so, then always save prot_type on a per se_node_acl node
 335                  * basis and re-instate the previous sess_prot_type to avoid
 336                  * disabling PI from below any previously initiator side
 337                  * registered LUNs.
 338                  */
 339                 if (se_nacl->saved_prot_type)
 340                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 341                 else if (tfo->tpg_check_prot_fabric_only)
 342                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 343                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 344                 /*
 345                  * If the fabric module supports an ISID based TransportID,
 346                  * save this value in binary from the fabric I_T Nexus now.
 347                  */
 348                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 349                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 350                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 351                                         &buf[0], PR_REG_ISID_LEN);
 352                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 353                 }
 354
 355                 spin_lock_irq(&se_nacl->nacl_sess_lock);
 356                 /*
 357                  * The se_nacl->nacl_sess pointer will be set to the
 358                  * last active I_T Nexus for each struct se_node_acl.
 359                  */
 360                 se_nacl->nacl_sess = se_sess;
 361
 362                 list_add_tail(&se_sess->sess_acl_list,
 363                               &se_nacl->acl_sess_list);
 364                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
 365         }
 366         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 367
 368         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 369                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 370 }
 371 EXPORT_SYMBOL(__transport_register_session);
 372
 373 void transport_register_session(
 374         struct se_portal_group *se_tpg,
 375         struct se_node_acl *se_nacl,
 376         struct se_session *se_sess,
 377         void *fabric_sess_ptr)
 378 {
 379         unsigned long flags;
 380
 381         spin_lock_irqsave(&se_tpg->session_lock, flags);
 382         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 383         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 384 }
 385 EXPORT_SYMBOL(transport_register_session);
 386
 387 struct se_session *
 388 target_alloc_session(struct se_portal_group *tpg,
 389                      unsigned int tag_num, unsigned int tag_size,
 390                      enum target_prot_op prot_op,
 391                      const char *initiatorname, void *private,
 392                      int (*callback)(struct se_portal_group *,
 393                                      struct se_session *, void *))
 394 {
 395         struct se_session *sess;
 396
 397         /*
 398          * If the fabric driver is using percpu-ida based pre allocation
 399          * of I/O descriptor tags, go ahead and perform that setup now..
 400          */
 401         if (tag_num != 0)
 402                 sess = transport_init_session_tags(tag_num, tag_size, prot_op);
 403         else
 404                 sess = transport_init_session(prot_op);
 405
 406         if (IS_ERR(sess))
 407                 return sess;
 408
 409         sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
 410                                         (unsigned char *)initiatorname);
 411         if (!sess->se_node_acl) {
 412                 transport_free_session(sess);
 413                 return ERR_PTR(-EACCES);
 414         }
 415         /*
 416          * Go ahead and perform any remaining fabric setup that is
 417          * required before transport_register_session().
 418          */
 419         if (callback != NULL) {
 420                 int rc = callback(tpg, sess, private);
 421                 if (rc) {
 422                         transport_free_session(sess);
 423                         return ERR_PTR(rc);
 424                 }
 425         }
 426
 427         transport_register_session(tpg, sess->se_node_acl, sess, private);
 428         return sess;
 429 }
 430 EXPORT_SYMBOL(target_alloc_session);
 431
 432 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 433 {
 434         struct se_session *se_sess;
 435         ssize_t len = 0;
 436
 437         spin_lock_bh(&se_tpg->session_lock);
 438         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 439                 if (!se_sess->se_node_acl)
 440                         continue;
 441                 if (!se_sess->se_node_acl->dynamic_node_acl)
 442                         continue;
 443                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 444                         break;
 445
 446                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 447                                 se_sess->se_node_acl->initiatorname);
 448                 len += 1; /* Include NULL terminator */
 449         }
 450         spin_unlock_bh(&se_tpg->session_lock);
 451
 452         return len;
 453 }
 454 EXPORT_SYMBOL(target_show_dynamic_sessions);
 455
 456 static void target_complete_nacl(struct kref *kref)
 457 {
 458         struct se_node_acl *nacl = container_of(kref,
 459                                 struct se_node_acl, acl_kref);
 460         struct se_portal_group *se_tpg = nacl->se_tpg;
 461
 462         if (!nacl->dynamic_stop) {
 463                 complete(&nacl->acl_free_comp);
 464                 return;
 465         }
 466
 467         mutex_lock(&se_tpg->acl_node_mutex);
 468         list_del_init(&nacl->acl_list);
 469         mutex_unlock(&se_tpg->acl_node_mutex);
 470
 471         core_tpg_wait_for_nacl_pr_ref(nacl);
 472         core_free_device_list_for_node(nacl, se_tpg);
 473         kfree(nacl);
 474 }
 475
 476 void target_put_nacl(struct se_node_acl *nacl)
 477 {
 478         kref_put(&nacl->acl_kref, target_complete_nacl);
 479 }
 480 EXPORT_SYMBOL(target_put_nacl);
 481
 482 void transport_deregister_session_configfs(struct se_session *se_sess)
 483 {
 484         struct se_node_acl *se_nacl;
 485         unsigned long flags;
 486         /*
 487          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 488          */
 489         se_nacl = se_sess->se_node_acl;
 490         if (se_nacl) {
 491                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 492                 if (!list_empty(&se_sess->sess_acl_list))
 493                         list_del_init(&se_sess->sess_acl_list);
 494                 /*
 495                  * If the session list is empty, then clear the pointer.
 496                  * Otherwise, set the struct se_session pointer from the tail
 497                  * element of the per struct se_node_acl active session list.
 498                  */
 499                 if (list_empty(&se_nacl->acl_sess_list))
 500                         se_nacl->nacl_sess = NULL;
 501                 else {
 502                         se_nacl->nacl_sess = container_of(
 503                                         se_nacl->acl_sess_list.prev,
 504                                         struct se_session, sess_acl_list);
 505                 }
 506                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 507         }
 508 }
 509 EXPORT_SYMBOL(transport_deregister_session_configfs);
 510
 511 void transport_free_session(struct se_session *se_sess)
 512 {
 513         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 514
 515         /*
 516          * Drop the se_node_acl->nacl_kref obtained from within
 517          * core_tpg_get_initiator_node_acl().
 518          */
 519         if (se_nacl) {
 520                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 521                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 522                 unsigned long flags;
 523
 524                 se_sess->se_node_acl = NULL;
 525
 526                 /*
 527                  * Also determine if we need to drop the extra ->cmd_kref if
 528                  * it had been previously dynamically generated, and
 529                  * the endpoint is not caching dynamic ACLs.
 530                  */
 531                 mutex_lock(&se_tpg->acl_node_mutex);
 532                 if (se_nacl->dynamic_node_acl &&
 533                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 534                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 535                         if (list_empty(&se_nacl->acl_sess_list))
 536                                 se_nacl->dynamic_stop = true;
 537                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 538
 539                         if (se_nacl->dynamic_stop)
 540                                 list_del_init(&se_nacl->acl_list);
 541                 }
 542                 mutex_unlock(&se_tpg->acl_node_mutex);
 543
 544                 if (se_nacl->dynamic_stop)
 545                         target_put_nacl(se_nacl);
 546
 547                 target_put_nacl(se_nacl);
 548         }
 549         if (se_sess->sess_cmd_map) {
 550                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 551                 kvfree(se_sess->sess_cmd_map);
 552         }
 553         kmem_cache_free(se_sess_cache, se_sess);
 554 }
 555 EXPORT_SYMBOL(transport_free_session);
 556
 557 void transport_deregister_session(struct se_session *se_sess)
 558 {
 559         struct se_portal_group *se_tpg = se_sess->se_tpg;
 560         unsigned long flags;
 561
 562         if (!se_tpg) {
 563                 transport_free_session(se_sess);
 564                 return;
 565         }
 566
 567         spin_lock_irqsave(&se_tpg->session_lock, flags);
 568         list_del(&se_sess->sess_list);
 569         se_sess->se_tpg = NULL;
 570         se_sess->fabric_sess_ptr = NULL;
 571         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 572
 573         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 574                 se_tpg->se_tpg_tfo->get_fabric_name());
 575         /*
 576          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 577          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 578          * removal context from within transport_free_session() code.
 579          *
 580          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 581          * to release all remaining generate_node_acl=1 created ACL resources.
 582          */
 583
 584         transport_free_session(se_sess);
 585 }
 586 EXPORT_SYMBOL(transport_deregister_session);
 587
 588 static void target_remove_from_state_list(struct se_cmd *cmd)
 589 {
 590         struct se_device *dev = cmd->se_dev;
 591         unsigned long flags;
 592
 593         if (!dev)
 594                 return;
 595
 596         spin_lock_irqsave(&dev->execute_task_lock, flags);
 597         if (cmd->state_active) {
 598                 list_del(&cmd->state_list);
 599                 cmd->state_active = false;
 600         }
 601         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 602 }
 603
 604 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 605 {
 606         unsigned long flags;
 607
 608         target_remove_from_state_list(cmd);
 609
 610         /*
 611          * Clear struct se_cmd->se_lun before the handoff to FE.
 612          */
 613         cmd->se_lun = NULL;
 614
 615         spin_lock_irqsave(&cmd->t_state_lock, flags);
 616         /*
 617          * Determine if frontend context caller is requesting the stopping of
 618          * this command for frontend exceptions.
 619          */
 620         if (cmd->transport_state & CMD_T_STOP) {
 621                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 622                         __func__, __LINE__, cmd->tag);
 623
 624                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 625
 626                 complete_all(&cmd->t_transport_stop_comp);
 627                 return 1;
 628         }
 629         cmd->transport_state &= ~CMD_T_ACTIVE;
 630         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 631
 632         /*
 633          * Some fabric modules like tcm_loop can release their internally
 634          * allocated I/O reference and struct se_cmd now.
 635          *
 636          * Fabric modules are expected to return '1' here if the se_cmd being
 637          * passed is released at this point, or zero if not being released.
 638          */
 639         return cmd->se_tfo->check_stop_free(cmd);
 640 }
 641
 642 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 643 {
 644         struct se_lun *lun = cmd->se_lun;
 645
 646         if (!lun)
 647                 return;
 648
 649         if (cmpxchg(&cmd->lun_ref_active, true, false))
 650                 percpu_ref_put(&lun->lun_ref);
 651 }
 652
 653 int transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 654 {
 655         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 656         int ret = 0;
 657
 658         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 659                 transport_lun_remove_cmd(cmd);
 660         /*
 661          * Allow the fabric driver to unmap any resources before
 662          * releasing the descriptor via TFO->release_cmd()
 663          */
 664         if (remove)
 665                 cmd->se_tfo->aborted_task(cmd);
 666
 667         if (transport_cmd_check_stop_to_fabric(cmd))
 668                 return 1;
 669         if (remove && ack_kref)
 670                 ret = target_put_sess_cmd(cmd);
 671
 672         return ret;
 673 }
 674
 675 static void target_complete_failure_work(struct work_struct *work)
 676 {
 677         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 678
 679         transport_generic_request_failure(cmd,
 680                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 681 }
 682
 683 /*
 684  * Used when asking transport to copy Sense Data from the underlying
 685  * Linux/SCSI struct scsi_cmnd
 686  */
 687 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 688 {
 689         struct se_device *dev = cmd->se_dev;
 690
 691         WARN_ON(!cmd->se_lun);
 692
 693         if (!dev)
 694                 return NULL;
 695
 696         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 697                 return NULL;
 698
 699         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 700
 701         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 702                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 703         return cmd->sense_buffer;
 704 }
 705
 706 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
 707 {
 708         unsigned char *cmd_sense_buf;
 709         unsigned long flags;
 710
 711         spin_lock_irqsave(&cmd->t_state_lock, flags);
 712         cmd_sense_buf = transport_get_sense_buffer(cmd);
 713         if (!cmd_sense_buf) {
 714                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 715                 return;
 716         }
 717
 718         cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
 719         memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
 720         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 721 }
 722 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
 723
 724 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 725 {
 726         struct se_device *dev = cmd->se_dev;
 727         int success;
 728         unsigned long flags;
 729
 730         cmd->scsi_status = scsi_status;
 731
 732         spin_lock_irqsave(&cmd->t_state_lock, flags);
 733         switch (cmd->scsi_status) {
 734         case SAM_STAT_CHECK_CONDITION:
 735                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 736                         success = 1;
 737                 else
 738                         success = 0;
 739                 break;
 740         default:
 741                 success = 1;
 742                 break;
 743         }
 744
 745         /*
 746          * Check for case where an explicit ABORT_TASK has been received
 747          * and transport_wait_for_tasks() will be waiting for completion..
 748          */
 749         if (cmd->transport_state & CMD_T_ABORTED ||
 750             cmd->transport_state & CMD_T_STOP) {
 751                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 752                 /*
 753                  * If COMPARE_AND_WRITE was stopped by __transport_wait_for_tasks(),
 754                  * release se_device->caw_sem obtained by sbc_compare_and_write()
 755                  * since target_complete_ok_work() or target_complete_failure_work()
 756                  * won't be called to invoke the normal CAW completion callbacks.
 757                  */
 758                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
 759                         up(&dev->caw_sem);
 760                 }
 761                 complete_all(&cmd->t_transport_stop_comp);
 762                 return;
 763         } else if (!success) {
 764                 INIT_WORK(&cmd->work, target_complete_failure_work);
 765         } else {
 766                 INIT_WORK(&cmd->work, target_complete_ok_work);
 767         }
 768
 769         cmd->t_state = TRANSPORT_COMPLETE;
 770         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 771         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 772
 773         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 774                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 775         else
 776                 queue_work(target_completion_wq, &cmd->work);
 777 }
 778 EXPORT_SYMBOL(target_complete_cmd);
 779
 780 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 781 {
 782         if ((scsi_status == SAM_STAT_GOOD ||
 783              cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
 784             length < cmd->data_length) {
 785                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 786                         cmd->residual_count += cmd->data_length - length;
 787                 } else {
 788                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 789                         cmd->residual_count = cmd->data_length - length;
 790                 }
 791
 792                 cmd->data_length = length;
 793         }
 794
 795         target_complete_cmd(cmd, scsi_status);
 796 }
 797 EXPORT_SYMBOL(target_complete_cmd_with_length);
 798
 799 static void target_add_to_state_list(struct se_cmd *cmd)
 800 {
 801         struct se_device *dev = cmd->se_dev;
 802         unsigned long flags;
 803
 804         spin_lock_irqsave(&dev->execute_task_lock, flags);
 805         if (!cmd->state_active) {
 806                 list_add_tail(&cmd->state_list, &dev->state_list);
 807                 cmd->state_active = true;
 808         }
 809         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 810 }
 811
 812 /*
 813  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 814  */
 815 static void transport_write_pending_qf(struct se_cmd *cmd);
 816 static void transport_complete_qf(struct se_cmd *cmd);
 817
 818 void target_qf_do_work(struct work_struct *work)
 819 {
 820         struct se_device *dev = container_of(work, struct se_device,
 821                                         qf_work_queue);
 822         LIST_HEAD(qf_cmd_list);
 823         struct se_cmd *cmd, *cmd_tmp;
 824
 825         spin_lock_irq(&dev->qf_cmd_lock);
 826         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 827         spin_unlock_irq(&dev->qf_cmd_lock);
 828
 829         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 830                 list_del(&cmd->se_qf_node);
 831                 atomic_dec_mb(&dev->dev_qf_count);
 832
 833                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 834                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 835                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 836                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 837                         : "UNKNOWN");
 838
 839                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 840                         transport_write_pending_qf(cmd);
 841                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 842                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 843                         transport_complete_qf(cmd);
 844         }
 845 }
 846
 847 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 848 {
 849         switch (cmd->data_direction) {
 850         case DMA_NONE:
 851                 return "NONE";
 852         case DMA_FROM_DEVICE:
 853                 return "READ";
 854         case DMA_TO_DEVICE:
 855                 return "WRITE";
 856         case DMA_BIDIRECTIONAL:
 857                 return "BIDI";
 858         default:
 859                 break;
 860         }
 861
 862         return "UNKNOWN";
 863 }
 864
 865 void transport_dump_dev_state(
 866         struct se_device *dev,
 867         char *b,
 868         int *bl)
 869 {
 870         *bl += sprintf(b + *bl, "Status: ");
 871         if (dev->export_count)
 872                 *bl += sprintf(b + *bl, "ACTIVATED");
 873         else
 874                 *bl += sprintf(b + *bl, "DEACTIVATED");
 875
 876         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 877         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 878                 dev->dev_attrib.block_size,
 879                 dev->dev_attrib.hw_max_sectors);
 880         *bl += sprintf(b + *bl, "        ");
 881 }
 882
 883 void transport_dump_vpd_proto_id(
 884         struct t10_vpd *vpd,
 885         unsigned char *p_buf,
 886         int p_buf_len)
 887 {
 888         unsigned char buf[VPD_TMP_BUF_SIZE];
 889         int len;
 890
 891         memset(buf, 0, VPD_TMP_BUF_SIZE);
 892         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 893
 894         switch (vpd->protocol_identifier) {
 895         case 0x00:
 896                 sprintf(buf+len, "Fibre Channel\n");
 897                 break;
 898         case 0x10:
 899                 sprintf(buf+len, "Parallel SCSI\n");
 900                 break;
 901         case 0x20:
 902                 sprintf(buf+len, "SSA\n");
 903                 break;
 904         case 0x30:
 905                 sprintf(buf+len, "IEEE 1394\n");
 906                 break;
 907         case 0x40:
 908                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 909                                 " Protocol\n");
 910                 break;
 911         case 0x50:
 912                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 913                 break;
 914         case 0x60:
 915                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 916                 break;
 917         case 0x70:
 918                 sprintf(buf+len, "Automation/Drive Interface Transport"
 919                                 " Protocol\n");
 920                 break;
 921         case 0x80:
 922                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 923                 break;
 924         default:
 925                 sprintf(buf+len, "Unknown 0x%02x\n",
 926                                 vpd->protocol_identifier);
 927                 break;
 928         }
 929
 930         if (p_buf)
 931                 strncpy(p_buf, buf, p_buf_len);
 932         else
 933                 pr_debug("%s", buf);
 934 }
 935
 936 void
 937 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 938 {
 939         /*
 940          * Check if the Protocol Identifier Valid (PIV) bit is set..
 941          *
 942          * from spc3r23.pdf section 7.5.1
 943          */
 944          if (page_83[1] & 0x80) {
 945                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 946                 vpd->protocol_identifier_set = 1;
 947                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 948         }
 949 }
 950 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 951
 952 int transport_dump_vpd_assoc(
 953         struct t10_vpd *vpd,
 954         unsigned char *p_buf,
 955         int p_buf_len)
 956 {
 957         unsigned char buf[VPD_TMP_BUF_SIZE];
 958         int ret = 0;
 959         int len;
 960
 961         memset(buf, 0, VPD_TMP_BUF_SIZE);
 962         len = sprintf(buf, "T10 VPD Identifier Association: ");
 963
 964         switch (vpd->association) {
 965         case 0x00:
 966                 sprintf(buf+len, "addressed logical unit\n");
 967                 break;
 968         case 0x10:
 969                 sprintf(buf+len, "target port\n");
 970                 break;
 971         case 0x20:
 972                 sprintf(buf+len, "SCSI target device\n");
 973                 break;
 974         default:
 975                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 976                 ret = -EINVAL;
 977                 break;
 978         }
 979
 980         if (p_buf)
 981                 strncpy(p_buf, buf, p_buf_len);
 982         else
 983                 pr_debug("%s", buf);
 984
 985         return ret;
 986 }
 987
 988 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 989 {
 990         /*
 991          * The VPD identification association..
 992          *
 993          * from spc3r23.pdf Section 7.6.3.1 Table 297
 994          */
 995         vpd->association = (page_83[1] & 0x30);
 996         return transport_dump_vpd_assoc(vpd, NULL, 0);
 997 }
 998 EXPORT_SYMBOL(transport_set_vpd_assoc);
 999
1000 int transport_dump_vpd_ident_type(
1001         struct t10_vpd *vpd,
1002         unsigned char *p_buf,
1003         int p_buf_len)
1004 {
1005         unsigned char buf[VPD_TMP_BUF_SIZE];
1006         int ret = 0;
1007         int len;
1008
1009         memset(buf, 0, VPD_TMP_BUF_SIZE);
1010         len = sprintf(buf, "T10 VPD Identifier Type: ");
1011
1012         switch (vpd->device_identifier_type) {
1013         case 0x00:
1014                 sprintf(buf+len, "Vendor specific\n");
1015                 break;
1016         case 0x01:
1017                 sprintf(buf+len, "T10 Vendor ID based\n");
1018                 break;
1019         case 0x02:
1020                 sprintf(buf+len, "EUI-64 based\n");
1021                 break;
1022         case 0x03:
1023                 sprintf(buf+len, "NAA\n");
1024                 break;
1025         case 0x04:
1026                 sprintf(buf+len, "Relative target port identifier\n");
1027                 break;
1028         case 0x08:
1029                 sprintf(buf+len, "SCSI name string\n");
1030                 break;
1031         default:
1032                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1033                                 vpd->device_identifier_type);
1034                 ret = -EINVAL;
1035                 break;
1036         }
1037
1038         if (p_buf) {
1039                 if (p_buf_len < strlen(buf)+1)
1040                         return -EINVAL;
1041                 strncpy(p_buf, buf, p_buf_len);
1042         } else {
1043                 pr_debug("%s", buf);
1044         }
1045
1046         return ret;
1047 }
1048
1049 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1050 {
1051         /*
1052          * The VPD identifier type..
1053          *
1054          * from spc3r23.pdf Section 7.6.3.1 Table 298
1055          */
1056         vpd->device_identifier_type = (page_83[1] & 0x0f);
1057         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1058 }
1059 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1060
1061 int transport_dump_vpd_ident(
1062         struct t10_vpd *vpd,
1063         unsigned char *p_buf,
1064         int p_buf_len)
1065 {
1066         unsigned char buf[VPD_TMP_BUF_SIZE];
1067         int ret = 0;
1068
1069         memset(buf, 0, VPD_TMP_BUF_SIZE);
1070
1071         switch (vpd->device_identifier_code_set) {
1072         case 0x01: /* Binary */
1073                 snprintf(buf, sizeof(buf),
1074                         "T10 VPD Binary Device Identifier: %s\n",
1075                         &vpd->device_identifier[0]);
1076                 break;
1077         case 0x02: /* ASCII */
1078                 snprintf(buf, sizeof(buf),
1079                         "T10 VPD ASCII Device Identifier: %s\n",
1080                         &vpd->device_identifier[0]);
1081                 break;
1082         case 0x03: /* UTF-8 */
1083                 snprintf(buf, sizeof(buf),
1084                         "T10 VPD UTF-8 Device Identifier: %s\n",
1085                         &vpd->device_identifier[0]);
1086                 break;
1087         default:
1088                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1089                         " 0x%02x", vpd->device_identifier_code_set);
1090                 ret = -EINVAL;
1091                 break;
1092         }
1093
1094         if (p_buf)
1095                 strncpy(p_buf, buf, p_buf_len);
1096         else
1097                 pr_debug("%s", buf);
1098
1099         return ret;
1100 }
1101
1102 int
1103 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1104 {
1105         static const char hex_str[] = "0123456789abcdef";
1106         int j = 0, i = 4; /* offset to start of the identifier */
1107
1108         /*
1109          * The VPD Code Set (encoding)
1110          *
1111          * from spc3r23.pdf Section 7.6.3.1 Table 296
1112          */
1113         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1114         switch (vpd->device_identifier_code_set) {
1115         case 0x01: /* Binary */
1116                 vpd->device_identifier[j++] =
1117                                 hex_str[vpd->device_identifier_type];
1118                 while (i < (4 + page_83[3])) {
1119                         vpd->device_identifier[j++] =
1120                                 hex_str[(page_83[i] & 0xf0) >> 4];
1121                         vpd->device_identifier[j++] =
1122                                 hex_str[page_83[i] & 0x0f];
1123                         i++;
1124                 }
1125                 break;
1126         case 0x02: /* ASCII */
1127         case 0x03: /* UTF-8 */
1128                 while (i < (4 + page_83[3]))
1129                         vpd->device_identifier[j++] = page_83[i++];
1130                 break;
1131         default:
1132                 break;
1133         }
1134
1135         return transport_dump_vpd_ident(vpd, NULL, 0);
1136 }
1137 EXPORT_SYMBOL(transport_set_vpd_ident);
1138
1139 static sense_reason_t
1140 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1141                                unsigned int size)
1142 {
1143         u32 mtl;
1144
1145         if (!cmd->se_tfo->max_data_sg_nents)
1146                 return TCM_NO_SENSE;
1147         /*
1148          * Check if fabric enforced maximum SGL entries per I/O descriptor
1149          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1150          * residual_count and reduce original cmd->data_length to maximum
1151          * length based on single PAGE_SIZE entry scatter-lists.
1152          */
1153         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1154         if (cmd->data_length > mtl) {
1155                 /*
1156                  * If an existing CDB overflow is present, calculate new residual
1157                  * based on CDB size minus fabric maximum transfer length.
1158                  *
1159                  * If an existing CDB underflow is present, calculate new residual
1160                  * based on original cmd->data_length minus fabric maximum transfer
1161                  * length.
1162                  *
1163                  * Otherwise, set the underflow residual based on cmd->data_length
1164                  * minus fabric maximum transfer length.
1165                  */
1166                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1167                         cmd->residual_count = (size - mtl);
1168                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1169                         u32 orig_dl = size + cmd->residual_count;
1170                         cmd->residual_count = (orig_dl - mtl);
1171                 } else {
1172                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1173                         cmd->residual_count = (cmd->data_length - mtl);
1174                 }
1175                 cmd->data_length = mtl;
1176                 /*
1177                  * Reset sbc_check_prot() calculated protection payload
1178                  * length based upon the new smaller MTL.
1179                  */
1180                 if (cmd->prot_length) {
1181                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1182                         cmd->prot_length = dev->prot_length * sectors;
1183                 }
1184         }
1185         return TCM_NO_SENSE;
1186 }
1187
1188 sense_reason_t
1189 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1190 {
1191         struct se_device *dev = cmd->se_dev;
1192
1193         if (cmd->unknown_data_length) {
1194                 cmd->data_length = size;
1195         } else if (size != cmd->data_length) {
1196                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1197                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1198                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1199                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1200
1201                 if (cmd->data_direction == DMA_TO_DEVICE) {
1202                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1203                                 pr_err_ratelimited("Rejecting underflow/overflow"
1204                                                    " for WRITE data CDB\n");
1205                                 return TCM_INVALID_CDB_FIELD;
1206                         }
1207                         /*
1208                          * Some fabric drivers like iscsi-target still expect to
1209                          * always reject overflow writes.  Reject this case until
1210                          * full fabric driver level support for overflow writes
1211                          * is introduced tree-wide.
1212                          */
1213                         if (size > cmd->data_length) {
1214                                 pr_err_ratelimited("Rejecting overflow for"
1215                                                    " WRITE control CDB\n");
1216                                 return TCM_INVALID_CDB_FIELD;
1217                         }
1218                 }
1219                 /*
1220                  * Reject READ_* or WRITE_* with overflow/underflow for
1221                  * type SCF_SCSI_DATA_CDB.
1222                  */
1223                 if (dev->dev_attrib.block_size != 512)  {
1224                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1225                                 " CDB on non 512-byte sector setup subsystem"
1226                                 " plugin: %s\n", dev->transport->name);
1227                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1228                         return TCM_INVALID_CDB_FIELD;
1229                 }
1230                 /*
1231                  * For the overflow case keep the existing fabric provided
1232                  * ->data_length.  Otherwise for the underflow case, reset
1233                  * ->data_length to the smaller SCSI expected data transfer
1234                  * length.
1235                  */
1236                 if (size > cmd->data_length) {
1237                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1238                         cmd->residual_count = (size - cmd->data_length);
1239                 } else {
1240                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1241                         cmd->residual_count = (cmd->data_length - size);
1242                         cmd->data_length = size;
1243                 }
1244         }
1245
1246         return target_check_max_data_sg_nents(cmd, dev, size);
1247
1248 }
1249
1250 /*
1251  * Used by fabric modules containing a local struct se_cmd within their
1252  * fabric dependent per I/O descriptor.
1253  *
1254  * Preserves the value of @cmd->tag.
1255  */
1256 void transport_init_se_cmd(
1257         struct se_cmd *cmd,
1258         const struct target_core_fabric_ops *tfo,
1259         struct se_session *se_sess,
1260         u32 data_length,
1261         int data_direction,
1262         int task_attr,
1263         unsigned char *sense_buffer)
1264 {
1265         INIT_LIST_HEAD(&cmd->se_delayed_node);
1266         INIT_LIST_HEAD(&cmd->se_qf_node);
1267         INIT_LIST_HEAD(&cmd->se_cmd_list);
1268         INIT_LIST_HEAD(&cmd->state_list);
1269         init_completion(&cmd->t_transport_stop_comp);
1270         init_completion(&cmd->cmd_wait_comp);
1271         spin_lock_init(&cmd->t_state_lock);
1272         INIT_WORK(&cmd->work, NULL);
1273         kref_init(&cmd->cmd_kref);
1274
1275         cmd->se_tfo = tfo;
1276         cmd->se_sess = se_sess;
1277         cmd->data_length = data_length;
1278         cmd->data_direction = data_direction;
1279         cmd->sam_task_attr = task_attr;
1280         cmd->sense_buffer = sense_buffer;
1281
1282         cmd->state_active = false;
1283 }
1284 EXPORT_SYMBOL(transport_init_se_cmd);
1285
1286 static sense_reason_t
1287 transport_check_alloc_task_attr(struct se_cmd *cmd)
1288 {
1289         struct se_device *dev = cmd->se_dev;
1290
1291         /*
1292          * Check if SAM Task Attribute emulation is enabled for this
1293          * struct se_device storage object
1294          */
1295         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1296                 return 0;
1297
1298         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1299                 pr_debug("SAM Task Attribute ACA"
1300                         " emulation is not supported\n");
1301                 return TCM_INVALID_CDB_FIELD;
1302         }
1303
1304         return 0;
1305 }
1306
1307 sense_reason_t
1308 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1309 {
1310         struct se_device *dev = cmd->se_dev;
1311         sense_reason_t ret;
1312
1313         /*
1314          * Ensure that the received CDB is less than the max (252 + 8) bytes
1315          * for VARIABLE_LENGTH_CMD
1316          */
1317         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1318                 pr_err("Received SCSI CDB with command_size: %d that"
1319                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1320                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1321                 return TCM_INVALID_CDB_FIELD;
1322         }
1323         /*
1324          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1325          * allocate the additional extended CDB buffer now..  Otherwise
1326          * setup the pointer from __t_task_cdb to t_task_cdb.
1327          */
1328         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1329                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1330                                                 GFP_KERNEL);
1331                 if (!cmd->t_task_cdb) {
1332                         pr_err("Unable to allocate cmd->t_task_cdb"
1333                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1334                                 scsi_command_size(cdb),
1335                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1336                         return TCM_OUT_OF_RESOURCES;
1337                 }
1338         } else
1339                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1340         /*
1341          * Copy the original CDB into cmd->
1342          */
1343         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1344
1345         trace_target_sequencer_start(cmd);
1346
1347         ret = dev->transport->parse_cdb(cmd);
1348         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1349                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1350                                     cmd->se_tfo->get_fabric_name(),
1351                                     cmd->se_sess->se_node_acl->initiatorname,
1352                                     cmd->t_task_cdb[0]);
1353         if (ret)
1354                 return ret;
1355
1356         ret = transport_check_alloc_task_attr(cmd);
1357         if (ret)
1358                 return ret;
1359
1360         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1361         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1362         return 0;
1363 }
1364 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1365
1366 /*
1367  * Used by fabric module frontends to queue tasks directly.
1368  * May only be used from process context.
1369  */
1370 int transport_handle_cdb_direct(
1371         struct se_cmd *cmd)
1372 {
1373         sense_reason_t ret;
1374
1375         if (!cmd->se_lun) {
1376                 dump_stack();
1377                 pr_err("cmd->se_lun is NULL\n");
1378                 return -EINVAL;
1379         }
1380         if (in_interrupt()) {
1381                 dump_stack();
1382                 pr_err("transport_generic_handle_cdb cannot be called"
1383                                 " from interrupt context\n");
1384                 return -EINVAL;
1385         }
1386         /*
1387          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1388          * outstanding descriptors are handled correctly during shutdown via
1389          * transport_wait_for_tasks()
1390          *
1391          * Also, we don't take cmd->t_state_lock here as we only expect
1392          * this to be called for initial descriptor submission.
1393          */
1394         cmd->t_state = TRANSPORT_NEW_CMD;
1395         cmd->transport_state |= CMD_T_ACTIVE;
1396
1397         /*
1398          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1399          * so follow TRANSPORT_NEW_CMD processing thread context usage
1400          * and call transport_generic_request_failure() if necessary..
1401          */
1402         ret = transport_generic_new_cmd(cmd);
1403         if (ret)
1404                 transport_generic_request_failure(cmd, ret);
1405         return 0;
1406 }
1407 EXPORT_SYMBOL(transport_handle_cdb_direct);
1408
1409 sense_reason_t
1410 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1411                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1412 {
1413         if (!sgl || !sgl_count)
1414                 return 0;
1415
1416         /*
1417          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1418          * scatterlists already have been set to follow what the fabric
1419          * passes for the original expected data transfer length.
1420          */
1421         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1422                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1423                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1424                 return TCM_INVALID_CDB_FIELD;
1425         }
1426
1427         cmd->t_data_sg = sgl;
1428         cmd->t_data_nents = sgl_count;
1429         cmd->t_bidi_data_sg = sgl_bidi;
1430         cmd->t_bidi_data_nents = sgl_bidi_count;
1431
1432         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1433         return 0;
1434 }
1435
1436 /**
1437  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1438  *                       se_cmd + use pre-allocated SGL memory.
1439  *
1440  * @se_cmd: command descriptor to submit
1441  * @se_sess: associated se_sess for endpoint
1442  * @cdb: pointer to SCSI CDB
1443  * @sense: pointer to SCSI sense buffer
1444  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1445  * @data_length: fabric expected data transfer length
1446  * @task_attr: SAM task attribute
1447  * @data_dir: DMA data direction
1448  * @flags: flags for command submission from target_sc_flags_tables
1449  * @sgl: struct scatterlist memory for unidirectional mapping
1450  * @sgl_count: scatterlist count for unidirectional mapping
1451  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1452  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1453  * @sgl_prot: struct scatterlist memory protection information
1454  * @sgl_prot_count: scatterlist count for protection information
1455  *
1456  * Task tags are supported if the caller has set @se_cmd->tag.
1457  *
1458  * Returns non zero to signal active I/O shutdown failure.  All other
1459  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1460  * but still return zero here.
1461  *
1462  * This may only be called from process context, and also currently
1463  * assumes internal allocation of fabric payload buffer by target-core.
1464  */
1465 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1466                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1467                 u32 data_length, int task_attr, int data_dir, int flags,
1468                 struct scatterlist *sgl, u32 sgl_count,
1469                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1470                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1471 {
1472         struct se_portal_group *se_tpg;
1473         sense_reason_t rc;
1474         int ret;
1475
1476         se_tpg = se_sess->se_tpg;
1477         BUG_ON(!se_tpg);
1478         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1479         BUG_ON(in_interrupt());
1480         /*
1481          * Initialize se_cmd for target operation.  From this point
1482          * exceptions are handled by sending exception status via
1483          * target_core_fabric_ops->queue_status() callback
1484          */
1485         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1486                                 data_length, data_dir, task_attr, sense);
1487
1488         if (flags & TARGET_SCF_USE_CPUID)
1489                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1490         else
1491                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1492
1493         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1494                 se_cmd->unknown_data_length = 1;
1495         /*
1496          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1497          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1498          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1499          * kref_put() to happen during fabric packet acknowledgement.
1500          */
1501         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1502         if (ret)
1503                 return ret;
1504         /*
1505          * Signal bidirectional data payloads to target-core
1506          */
1507         if (flags & TARGET_SCF_BIDI_OP)
1508                 se_cmd->se_cmd_flags |= SCF_BIDI;
1509         /*
1510          * Locate se_lun pointer and attach it to struct se_cmd
1511          */
1512         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1513         if (rc) {
1514                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1515                 target_put_sess_cmd(se_cmd);
1516                 return 0;
1517         }
1518
1519         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1520         if (rc != 0) {
1521                 transport_generic_request_failure(se_cmd, rc);
1522                 return 0;
1523         }
1524
1525         /*
1526          * Save pointers for SGLs containing protection information,
1527          * if present.
1528          */
1529         if (sgl_prot_count) {
1530                 se_cmd->t_prot_sg = sgl_prot;
1531                 se_cmd->t_prot_nents = sgl_prot_count;
1532                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1533         }
1534
1535         /*
1536          * When a non zero sgl_count has been passed perform SGL passthrough
1537          * mapping for pre-allocated fabric memory instead of having target
1538          * core perform an internal SGL allocation..
1539          */
1540         if (sgl_count != 0) {
1541                 BUG_ON(!sgl);
1542
1543                 /*
1544                  * A work-around for tcm_loop as some userspace code via
1545                  * scsi-generic do not memset their associated read buffers,
1546                  * so go ahead and do that here for type non-data CDBs.  Also
1547                  * note that this is currently guaranteed to be a single SGL
1548                  * for this case by target core in target_setup_cmd_from_cdb()
1549                  * -> transport_generic_cmd_sequencer().
1550                  */
1551                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1552                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1553                         unsigned char *buf = NULL;
1554
1555                         if (sgl)
1556                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1557
1558                         if (buf) {
1559                                 memset(buf, 0, sgl->length);
1560                                 kunmap(sg_page(sgl));
1561                         }
1562                 }
1563
1564                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1565                                 sgl_bidi, sgl_bidi_count);
1566                 if (rc != 0) {
1567                         transport_generic_request_failure(se_cmd, rc);
1568                         return 0;
1569                 }
1570         }
1571
1572         /*
1573          * Check if we need to delay processing because of ALUA
1574          * Active/NonOptimized primary access state..
1575          */
1576         core_alua_check_nonop_delay(se_cmd);
1577
1578         transport_handle_cdb_direct(se_cmd);
1579         return 0;
1580 }
1581 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1582
1583 /**
1584  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1585  *
1586  * @se_cmd: command descriptor to submit
1587  * @se_sess: associated se_sess for endpoint
1588  * @cdb: pointer to SCSI CDB
1589  * @sense: pointer to SCSI sense buffer
1590  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1591  * @data_length: fabric expected data transfer length
1592  * @task_attr: SAM task attribute
1593  * @data_dir: DMA data direction
1594  * @flags: flags for command submission from target_sc_flags_tables
1595  *
1596  * Task tags are supported if the caller has set @se_cmd->tag.
1597  *
1598  * Returns non zero to signal active I/O shutdown failure.  All other
1599  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1600  * but still return zero here.
1601  *
1602  * This may only be called from process context, and also currently
1603  * assumes internal allocation of fabric payload buffer by target-core.
1604  *
1605  * It also assumes interal target core SGL memory allocation.
1606  */
1607 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1608                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1609                 u32 data_length, int task_attr, int data_dir, int flags)
1610 {
1611         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1612                         unpacked_lun, data_length, task_attr, data_dir,
1613                         flags, NULL, 0, NULL, 0, NULL, 0);
1614 }
1615 EXPORT_SYMBOL(target_submit_cmd);
1616
1617 static void target_complete_tmr_failure(struct work_struct *work)
1618 {
1619         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1620
1621         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1622         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1623
1624         transport_lun_remove_cmd(se_cmd);
1625         transport_cmd_check_stop_to_fabric(se_cmd);
1626 }
1627
1628 static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
1629                                        u64 *unpacked_lun)
1630 {
1631         struct se_cmd *se_cmd;
1632         unsigned long flags;
1633         bool ret = false;
1634
1635         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
1636         list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
1637                 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1638                         continue;
1639
1640                 if (se_cmd->tag == tag) {
1641                         *unpacked_lun = se_cmd->orig_fe_lun;
1642                         ret = true;
1643                         break;
1644                 }
1645         }
1646         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
1647
1648         return ret;
1649 }
1650
1651 /**
1652  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1653  *                     for TMR CDBs
1654  *
1655  * @se_cmd: command descriptor to submit
1656  * @se_sess: associated se_sess for endpoint
1657  * @sense: pointer to SCSI sense buffer
1658  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1659  * @fabric_tmr_ptr: fabric context for TMR req
1660  * @tm_type: Type of TM request
1661  * @gfp: gfp type for caller
1662  * @tag: referenced task tag for TMR_ABORT_TASK
1663  * @flags: submit cmd flags
1664  *
1665  * Callable from all contexts.
1666  **/
1667
1668 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1669                 unsigned char *sense, u64 unpacked_lun,
1670                 void *fabric_tmr_ptr, unsigned char tm_type,
1671                 gfp_t gfp, u64 tag, int flags)
1672 {
1673         struct se_portal_group *se_tpg;
1674         int ret;
1675
1676         se_tpg = se_sess->se_tpg;
1677         BUG_ON(!se_tpg);
1678
1679         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1680                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1681         /*
1682          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1683          * allocation failure.
1684          */
1685         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1686         if (ret < 0)
1687                 return -ENOMEM;
1688
1689         if (tm_type == TMR_ABORT_TASK)
1690                 se_cmd->se_tmr_req->ref_task_tag = tag;
1691
1692         /* See target_submit_cmd for commentary */
1693         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1694         if (ret) {
1695                 core_tmr_release_req(se_cmd->se_tmr_req);
1696                 return ret;
1697         }
1698         /*
1699          * If this is ABORT_TASK with no explicit fabric provided LUN,
1700          * go ahead and search active session tags for a match to figure
1701          * out unpacked_lun for the original se_cmd.
1702          */
1703         if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
1704                 if (!target_lookup_lun_from_tag(se_sess, tag, &unpacked_lun))
1705                         goto failure;
1706         }
1707
1708         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1709         if (ret)
1710                 goto failure;
1711
1712         transport_generic_handle_tmr(se_cmd);
1713         return 0;
1714
1715         /*
1716          * For callback during failure handling, push this work off
1717          * to process context with TMR_LUN_DOES_NOT_EXIST status.
1718          */
1719 failure:
1720         INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1721         schedule_work(&se_cmd->work);
1722         return 0;
1723 }
1724 EXPORT_SYMBOL(target_submit_tmr);
1725
1726 /*
1727  * Handle SAM-esque emulation for generic transport request failures.
1728  */
1729 void transport_generic_request_failure(struct se_cmd *cmd,
1730                 sense_reason_t sense_reason)
1731 {
1732         int ret = 0, post_ret = 0;
1733
1734         pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
1735                  sense_reason);
1736         target_show_cmd("-----[ ", cmd);
1737
1738         /*
1739          * For SAM Task Attribute emulation for failed struct se_cmd
1740          */
1741         transport_complete_task_attr(cmd);
1742
1743         /*
1744          * Handle special case for COMPARE_AND_WRITE failure, where the
1745          * callback is expected to drop the per device ->caw_sem.
1746          */
1747         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1748              cmd->transport_complete_callback)
1749                 cmd->transport_complete_callback(cmd, false, &post_ret);
1750
1751         if (transport_check_aborted_status(cmd, 1))
1752                 return;
1753
1754         switch (sense_reason) {
1755         case TCM_NON_EXISTENT_LUN:
1756         case TCM_UNSUPPORTED_SCSI_OPCODE:
1757         case TCM_INVALID_CDB_FIELD:
1758         case TCM_INVALID_PARAMETER_LIST:
1759         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1760         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1761         case TCM_UNKNOWN_MODE_PAGE:
1762         case TCM_WRITE_PROTECTED:
1763         case TCM_ADDRESS_OUT_OF_RANGE:
1764         case TCM_CHECK_CONDITION_ABORT_CMD:
1765         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1766         case TCM_CHECK_CONDITION_NOT_READY:
1767         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1768         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1769         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1770         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1771         case TCM_TOO_MANY_TARGET_DESCS:
1772         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1773         case TCM_TOO_MANY_SEGMENT_DESCS:
1774         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1775                 break;
1776         case TCM_OUT_OF_RESOURCES:
1777                 cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
1778                 goto queue_status;
1779         case TCM_LUN_BUSY:
1780                 cmd->scsi_status = SAM_STAT_BUSY;
1781                 goto queue_status;
1782         case TCM_RESERVATION_CONFLICT:
1783                 /*
1784                  * No SENSE Data payload for this case, set SCSI Status
1785                  * and queue the response to $FABRIC_MOD.
1786                  *
1787                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1788                  */
1789                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1790                 /*
1791                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1792                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1793                  * CONFLICT STATUS.
1794                  *
1795                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1796                  */
1797                 if (cmd->se_sess &&
1798                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1799                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1800                                                cmd->orig_fe_lun, 0x2C,
1801                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1802                 }
1803
1804                 goto queue_status;
1805         default:
1806                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1807                         cmd->t_task_cdb[0], sense_reason);
1808                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1809                 break;
1810         }
1811
1812         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1813         if (ret)
1814                 goto queue_full;
1815
1816 check_stop:
1817         transport_lun_remove_cmd(cmd);
1818         transport_cmd_check_stop_to_fabric(cmd);
1819         return;
1820
1821 queue_status:
1822         trace_target_cmd_complete(cmd);
1823         ret = cmd->se_tfo->queue_status(cmd);
1824         if (!ret)
1825                 goto check_stop;
1826 queue_full:
1827         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1828 }
1829 EXPORT_SYMBOL(transport_generic_request_failure);
1830
1831 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1832 {
1833         sense_reason_t ret;
1834
1835         if (!cmd->execute_cmd) {
1836                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1837                 goto err;
1838         }
1839         if (do_checks) {
1840                 /*
1841                  * Check for an existing UNIT ATTENTION condition after
1842                  * target_handle_task_attr() has done SAM task attr
1843                  * checking, and possibly have already defered execution
1844                  * out to target_restart_delayed_cmds() context.
1845                  */
1846                 ret = target_scsi3_ua_check(cmd);
1847                 if (ret)
1848                         goto err;
1849
1850                 ret = target_alua_state_check(cmd);
1851                 if (ret)
1852                         goto err;
1853
1854                 ret = target_check_reservation(cmd);
1855                 if (ret) {
1856                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1857                         goto err;
1858                 }
1859         }
1860
1861         ret = cmd->execute_cmd(cmd);
1862         if (!ret)
1863                 return;
1864 err:
1865         spin_lock_irq(&cmd->t_state_lock);
1866         cmd->transport_state &= ~CMD_T_SENT;
1867         spin_unlock_irq(&cmd->t_state_lock);
1868
1869         transport_generic_request_failure(cmd, ret);
1870 }
1871
1872 static int target_write_prot_action(struct se_cmd *cmd)
1873 {
1874         u32 sectors;
1875         /*
1876          * Perform WRITE_INSERT of PI using software emulation when backend
1877          * device has PI enabled, if the transport has not already generated
1878          * PI using hardware WRITE_INSERT offload.
1879          */
1880         switch (cmd->prot_op) {
1881         case TARGET_PROT_DOUT_INSERT:
1882                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1883                         sbc_dif_generate(cmd);
1884                 break;
1885         case TARGET_PROT_DOUT_STRIP:
1886                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1887                         break;
1888
1889                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1890                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1891                                              sectors, 0, cmd->t_prot_sg, 0);
1892                 if (unlikely(cmd->pi_err)) {
1893                         spin_lock_irq(&cmd->t_state_lock);
1894                         cmd->transport_state &= ~CMD_T_SENT;
1895                         spin_unlock_irq(&cmd->t_state_lock);
1896                         transport_generic_request_failure(cmd, cmd->pi_err);
1897                         return -1;
1898                 }
1899                 break;
1900         default:
1901                 break;
1902         }
1903
1904         return 0;
1905 }
1906
1907 static bool target_handle_task_attr(struct se_cmd *cmd)
1908 {
1909         struct se_device *dev = cmd->se_dev;
1910
1911         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1912                 return false;
1913
1914         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1915
1916         /*
1917          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1918          * to allow the passed struct se_cmd list of tasks to the front of the list.
1919          */
1920         switch (cmd->sam_task_attr) {
1921         case TCM_HEAD_TAG:
1922                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1923                          cmd->t_task_cdb[0]);
1924                 return false;
1925         case TCM_ORDERED_TAG:
1926                 atomic_inc_mb(&dev->dev_ordered_sync);
1927
1928                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1929                          cmd->t_task_cdb[0]);
1930
1931                 /*
1932                  * Execute an ORDERED command if no other older commands
1933                  * exist that need to be completed first.
1934                  */
1935                 if (!atomic_read(&dev->simple_cmds))
1936                         return false;
1937                 break;
1938         default:
1939                 /*
1940                  * For SIMPLE and UNTAGGED Task Attribute commands
1941                  */
1942                 atomic_inc_mb(&dev->simple_cmds);
1943                 break;
1944         }
1945
1946         if (atomic_read(&dev->dev_ordered_sync) == 0)
1947                 return false;
1948
1949         spin_lock(&dev->delayed_cmd_lock);
1950         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1951         spin_unlock(&dev->delayed_cmd_lock);
1952
1953         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1954                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1955         return true;
1956 }
1957
1958 static int __transport_check_aborted_status(struct se_cmd *, int);
1959
1960 void target_execute_cmd(struct se_cmd *cmd)
1961 {
1962         /*
1963          * Determine if frontend context caller is requesting the stopping of
1964          * this command for frontend exceptions.
1965          *
1966          * If the received CDB has aleady been aborted stop processing it here.
1967          */
1968         spin_lock_irq(&cmd->t_state_lock);
1969         if (__transport_check_aborted_status(cmd, 1)) {
1970                 spin_unlock_irq(&cmd->t_state_lock);
1971                 return;
1972         }
1973         if (cmd->transport_state & CMD_T_STOP) {
1974                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1975                         __func__, __LINE__, cmd->tag);
1976
1977                 spin_unlock_irq(&cmd->t_state_lock);
1978                 complete_all(&cmd->t_transport_stop_comp);
1979                 return;
1980         }
1981
1982         cmd->t_state = TRANSPORT_PROCESSING;
1983         cmd->transport_state &= ~CMD_T_PRE_EXECUTE;
1984         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
1985         spin_unlock_irq(&cmd->t_state_lock);
1986
1987         if (target_write_prot_action(cmd))
1988                 return;
1989
1990         if (target_handle_task_attr(cmd)) {
1991                 spin_lock_irq(&cmd->t_state_lock);
1992                 cmd->transport_state &= ~CMD_T_SENT;
1993                 spin_unlock_irq(&cmd->t_state_lock);
1994                 return;
1995         }
1996
1997         __target_execute_cmd(cmd, true);
1998 }
1999 EXPORT_SYMBOL(target_execute_cmd);
2000
2001 /*
2002  * Process all commands up to the last received ORDERED task attribute which
2003  * requires another blocking boundary
2004  */
2005 static void target_restart_delayed_cmds(struct se_device *dev)
2006 {
2007         for (;;) {
2008                 struct se_cmd *cmd;
2009
2010                 spin_lock(&dev->delayed_cmd_lock);
2011                 if (list_empty(&dev->delayed_cmd_list)) {
2012                         spin_unlock(&dev->delayed_cmd_lock);
2013                         break;
2014                 }
2015
2016                 cmd = list_entry(dev->delayed_cmd_list.next,
2017                                  struct se_cmd, se_delayed_node);
2018                 list_del(&cmd->se_delayed_node);
2019                 spin_unlock(&dev->delayed_cmd_lock);
2020
2021                 cmd->transport_state |= CMD_T_SENT;
2022
2023                 __target_execute_cmd(cmd, true);
2024
2025                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
2026                         break;
2027         }
2028 }
2029
2030 /*
2031  * Called from I/O completion to determine which dormant/delayed
2032  * and ordered cmds need to have their tasks added to the execution queue.
2033  */
2034 static void transport_complete_task_attr(struct se_cmd *cmd)
2035 {
2036         struct se_device *dev = cmd->se_dev;
2037
2038         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2039                 return;
2040
2041         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2042                 goto restart;
2043
2044         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2045                 atomic_dec_mb(&dev->simple_cmds);
2046                 dev->dev_cur_ordered_id++;
2047         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2048                 dev->dev_cur_ordered_id++;
2049                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2050                          dev->dev_cur_ordered_id);
2051         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2052                 atomic_dec_mb(&dev->dev_ordered_sync);
2053
2054                 dev->dev_cur_ordered_id++;
2055                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2056                          dev->dev_cur_ordered_id);
2057         }
2058         cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2059
2060 restart:
2061         target_restart_delayed_cmds(dev);
2062 }
2063
2064 static void transport_complete_qf(struct se_cmd *cmd)
2065 {
2066         int ret = 0;
2067
2068         transport_complete_task_attr(cmd);
2069         /*
2070          * If a fabric driver ->write_pending() or ->queue_data_in() callback
2071          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2072          * the same callbacks should not be retried.  Return CHECK_CONDITION
2073          * if a scsi_status is not already set.
2074          *
2075          * If a fabric driver ->queue_status() has returned non zero, always
2076          * keep retrying no matter what..
2077          */
2078         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2079                 if (cmd->scsi_status)
2080                         goto queue_status;
2081
2082                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2083                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2084                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2085                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2086                 goto queue_status;
2087         }
2088
2089         /*
2090          * Check if we need to send a sense buffer from
2091          * the struct se_cmd in question. We do NOT want
2092          * to take this path of the IO has been marked as
2093          * needing to be treated like a "normal read". This
2094          * is the case if it's a tape read, and either the
2095          * FM, EOM, or ILI bits are set, but there is no
2096          * sense data.
2097          */
2098         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2099             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2100                 goto queue_status;
2101
2102         switch (cmd->data_direction) {
2103         case DMA_FROM_DEVICE:
2104                 /* queue status if not treating this as a normal read */
2105                 if (cmd->scsi_status &&
2106                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2107                         goto queue_status;
2108
2109                 trace_target_cmd_complete(cmd);
2110                 ret = cmd->se_tfo->queue_data_in(cmd);
2111                 break;
2112         case DMA_TO_DEVICE:
2113                 if (cmd->se_cmd_flags & SCF_BIDI) {
2114                         ret = cmd->se_tfo->queue_data_in(cmd);
2115                         break;
2116                 }
2117                 /* fall through */
2118         case DMA_NONE:
2119 queue_status:
2120                 trace_target_cmd_complete(cmd);
2121                 ret = cmd->se_tfo->queue_status(cmd);
2122                 break;
2123         default:
2124                 break;
2125         }
2126
2127         if (ret < 0) {
2128                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2129                 return;
2130         }
2131         transport_lun_remove_cmd(cmd);
2132         transport_cmd_check_stop_to_fabric(cmd);
2133 }
2134
2135 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2136                                         int err, bool write_pending)
2137 {
2138         /*
2139          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2140          * ->queue_data_in() callbacks from new process context.
2141          *
2142          * Otherwise for other errors, transport_complete_qf() will send
2143          * CHECK_CONDITION via ->queue_status() instead of attempting to
2144          * retry associated fabric driver data-transfer callbacks.
2145          */
2146         if (err == -EAGAIN || err == -ENOMEM) {
2147                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2148                                                  TRANSPORT_COMPLETE_QF_OK;
2149         } else {
2150                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2151                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2152         }
2153
2154         spin_lock_irq(&dev->qf_cmd_lock);
2155         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2156         atomic_inc_mb(&dev->dev_qf_count);
2157         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2158
2159         schedule_work(&cmd->se_dev->qf_work_queue);
2160 }
2161
2162 static bool target_read_prot_action(struct se_cmd *cmd)
2163 {
2164         switch (cmd->prot_op) {
2165         case TARGET_PROT_DIN_STRIP:
2166                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2167                         u32 sectors = cmd->data_length >>
2168                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2169
2170                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2171                                                      sectors, 0, cmd->t_prot_sg,
2172                                                      0);
2173                         if (cmd->pi_err)
2174                                 return true;
2175                 }
2176                 break;
2177         case TARGET_PROT_DIN_INSERT:
2178                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2179                         break;
2180
2181                 sbc_dif_generate(cmd);
2182                 break;
2183         default:
2184                 break;
2185         }
2186
2187         return false;
2188 }
2189
2190 static void target_complete_ok_work(struct work_struct *work)
2191 {
2192         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2193         int ret;
2194
2195         /*
2196          * Check if we need to move delayed/dormant tasks from cmds on the
2197          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2198          * Attribute.
2199          */
2200         transport_complete_task_attr(cmd);
2201
2202         /*
2203          * Check to schedule QUEUE_FULL work, or execute an existing
2204          * cmd->transport_qf_callback()
2205          */
2206         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2207                 schedule_work(&cmd->se_dev->qf_work_queue);
2208
2209         /*
2210          * Check if we need to send a sense buffer from
2211          * the struct se_cmd in question. We do NOT want
2212          * to take this path of the IO has been marked as
2213          * needing to be treated like a "normal read". This
2214          * is the case if it's a tape read, and either the
2215          * FM, EOM, or ILI bits are set, but there is no
2216          * sense data.
2217          */
2218         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2219             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2220                 WARN_ON(!cmd->scsi_status);
2221                 ret = transport_send_check_condition_and_sense(
2222                                         cmd, 0, 1);
2223                 if (ret)
2224                         goto queue_full;
2225
2226                 transport_lun_remove_cmd(cmd);
2227                 transport_cmd_check_stop_to_fabric(cmd);
2228                 return;
2229         }
2230         /*
2231          * Check for a callback, used by amongst other things
2232          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2233          */
2234         if (cmd->transport_complete_callback) {
2235                 sense_reason_t rc;
2236                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2237                 bool zero_dl = !(cmd->data_length);
2238                 int post_ret = 0;
2239
2240                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2241                 if (!rc && !post_ret) {
2242                         if (caw && zero_dl)
2243                                 goto queue_rsp;
2244
2245                         return;
2246                 } else if (rc) {
2247                         ret = transport_send_check_condition_and_sense(cmd,
2248                                                 rc, 0);
2249                         if (ret)
2250                                 goto queue_full;
2251
2252                         transport_lun_remove_cmd(cmd);
2253                         transport_cmd_check_stop_to_fabric(cmd);
2254                         return;
2255                 }
2256         }
2257
2258 queue_rsp:
2259         switch (cmd->data_direction) {
2260         case DMA_FROM_DEVICE:
2261                 /*
2262                  * if this is a READ-type IO, but SCSI status
2263                  * is set, then skip returning data and just
2264                  * return the status -- unless this IO is marked
2265                  * as needing to be treated as a normal read,
2266                  * in which case we want to go ahead and return
2267                  * the data. This happens, for example, for tape
2268                  * reads with the FM, EOM, or ILI bits set, with
2269                  * no sense data.
2270                  */
2271                 if (cmd->scsi_status &&
2272                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2273                         goto queue_status;
2274
2275                 atomic_long_add(cmd->data_length,
2276                                 &cmd->se_lun->lun_stats.tx_data_octets);
2277                 /*
2278                  * Perform READ_STRIP of PI using software emulation when
2279                  * backend had PI enabled, if the transport will not be
2280                  * performing hardware READ_STRIP offload.
2281                  */
2282                 if (target_read_prot_action(cmd)) {
2283                         ret = transport_send_check_condition_and_sense(cmd,
2284                                                 cmd->pi_err, 0);
2285                         if (ret)
2286                                 goto queue_full;
2287
2288                         transport_lun_remove_cmd(cmd);
2289                         transport_cmd_check_stop_to_fabric(cmd);
2290                         return;
2291                 }
2292
2293                 trace_target_cmd_complete(cmd);
2294                 ret = cmd->se_tfo->queue_data_in(cmd);
2295                 if (ret)
2296                         goto queue_full;
2297                 break;
2298         case DMA_TO_DEVICE:
2299                 atomic_long_add(cmd->data_length,
2300                                 &cmd->se_lun->lun_stats.rx_data_octets);
2301                 /*
2302                  * Check if we need to send READ payload for BIDI-COMMAND
2303                  */
2304                 if (cmd->se_cmd_flags & SCF_BIDI) {
2305                         atomic_long_add(cmd->data_length,
2306                                         &cmd->se_lun->lun_stats.tx_data_octets);
2307                         ret = cmd->se_tfo->queue_data_in(cmd);
2308                         if (ret)
2309                                 goto queue_full;
2310                         break;
2311                 }
2312                 /* fall through */
2313         case DMA_NONE:
2314 queue_status:
2315                 trace_target_cmd_complete(cmd);
2316                 ret = cmd->se_tfo->queue_status(cmd);
2317                 if (ret)
2318                         goto queue_full;
2319                 break;
2320         default:
2321                 break;
2322         }
2323
2324         transport_lun_remove_cmd(cmd);
2325         transport_cmd_check_stop_to_fabric(cmd);
2326         return;
2327
2328 queue_full:
2329         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2330                 " data_direction: %d\n", cmd, cmd->data_direction);
2331
2332         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2333 }
2334
2335 void target_free_sgl(struct scatterlist *sgl, int nents)
2336 {
2337         sgl_free_n_order(sgl, nents, 0);
2338 }
2339 EXPORT_SYMBOL(target_free_sgl);
2340
2341 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2342 {
2343         /*
2344          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2345          * emulation, and free + reset pointers if necessary..
2346          */
2347         if (!cmd->t_data_sg_orig)
2348                 return;
2349
2350         kfree(cmd->t_data_sg);
2351         cmd->t_data_sg = cmd->t_data_sg_orig;
2352         cmd->t_data_sg_orig = NULL;
2353         cmd->t_data_nents = cmd->t_data_nents_orig;
2354         cmd->t_data_nents_orig = 0;
2355 }
2356
2357 static inline void transport_free_pages(struct se_cmd *cmd)
2358 {
2359         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2360                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2361                 cmd->t_prot_sg = NULL;
2362                 cmd->t_prot_nents = 0;
2363         }
2364
2365         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2366                 /*
2367                  * Release special case READ buffer payload required for
2368                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2369                  */
2370                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2371                         target_free_sgl(cmd->t_bidi_data_sg,
2372                                            cmd->t_bidi_data_nents);
2373                         cmd->t_bidi_data_sg = NULL;
2374                         cmd->t_bidi_data_nents = 0;
2375                 }
2376                 transport_reset_sgl_orig(cmd);
2377                 return;
2378         }
2379         transport_reset_sgl_orig(cmd);
2380
2381         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2382         cmd->t_data_sg = NULL;
2383         cmd->t_data_nents = 0;
2384
2385         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2386         cmd->t_bidi_data_sg = NULL;
2387         cmd->t_bidi_data_nents = 0;
2388 }
2389
2390 void *transport_kmap_data_sg(struct se_cmd *cmd)
2391 {
2392         struct scatterlist *sg = cmd->t_data_sg;
2393         struct page **pages;
2394         int i;
2395
2396         /*
2397          * We need to take into account a possible offset here for fabrics like
2398          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2399          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2400          */
2401         if (!cmd->t_data_nents)
2402                 return NULL;
2403
2404         BUG_ON(!sg);
2405         if (cmd->t_data_nents == 1)
2406                 return kmap(sg_page(sg)) + sg->offset;
2407
2408         /* >1 page. use vmap */
2409         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2410         if (!pages)
2411                 return NULL;
2412
2413         /* convert sg[] to pages[] */
2414         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2415                 pages[i] = sg_page(sg);
2416         }
2417
2418         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2419         kfree(pages);
2420         if (!cmd->t_data_vmap)
2421                 return NULL;
2422
2423         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2424 }
2425 EXPORT_SYMBOL(transport_kmap_data_sg);
2426
2427 void transport_kunmap_data_sg(struct se_cmd *cmd)
2428 {
2429         if (!cmd->t_data_nents) {
2430                 return;
2431         } else if (cmd->t_data_nents == 1) {
2432                 kunmap(sg_page(cmd->t_data_sg));
2433                 return;
2434         }
2435
2436         vunmap(cmd->t_data_vmap);
2437         cmd->t_data_vmap = NULL;
2438 }
2439 EXPORT_SYMBOL(transport_kunmap_data_sg);
2440
2441 int
2442 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2443                  bool zero_page, bool chainable)
2444 {
2445         gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
2446
2447         *sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
2448         return *sgl ? 0 : -ENOMEM;
2449 }
2450 EXPORT_SYMBOL(target_alloc_sgl);
2451
2452 /*
2453  * Allocate any required resources to execute the command.  For writes we
2454  * might not have the payload yet, so notify the fabric via a call to
2455  * ->write_pending instead. Otherwise place it on the execution queue.
2456  */
2457 sense_reason_t
2458 transport_generic_new_cmd(struct se_cmd *cmd)
2459 {
2460         unsigned long flags;
2461         int ret = 0;
2462         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2463
2464         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2465             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2466                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2467                                        cmd->prot_length, true, false);
2468                 if (ret < 0)
2469                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2470         }
2471
2472         /*
2473          * Determine is the TCM fabric module has already allocated physical
2474          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2475          * beforehand.
2476          */
2477         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2478             cmd->data_length) {
2479
2480                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2481                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2482                         u32 bidi_length;
2483
2484                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2485                                 bidi_length = cmd->t_task_nolb *
2486                                               cmd->se_dev->dev_attrib.block_size;
2487                         else
2488                                 bidi_length = cmd->data_length;
2489
2490                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2491                                                &cmd->t_bidi_data_nents,
2492                                                bidi_length, zero_flag, false);
2493                         if (ret < 0)
2494                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2495                 }
2496
2497                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2498                                        cmd->data_length, zero_flag, false);
2499                 if (ret < 0)
2500                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2501         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2502                     cmd->data_length) {
2503                 /*
2504                  * Special case for COMPARE_AND_WRITE with fabrics
2505                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2506                  */
2507                 u32 caw_length = cmd->t_task_nolb *
2508                                  cmd->se_dev->dev_attrib.block_size;
2509
2510                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2511                                        &cmd->t_bidi_data_nents,
2512                                        caw_length, zero_flag, false);
2513                 if (ret < 0)
2514                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2515         }
2516         /*
2517          * If this command is not a write we can execute it right here,
2518          * for write buffers we need to notify the fabric driver first
2519          * and let it call back once the write buffers are ready.
2520          */
2521         target_add_to_state_list(cmd);
2522         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2523                 target_execute_cmd(cmd);
2524                 return 0;
2525         }
2526
2527         spin_lock_irqsave(&cmd->t_state_lock, flags);
2528         cmd->t_state = TRANSPORT_WRITE_PENDING;
2529         /*
2530          * Determine if frontend context caller is requesting the stopping of
2531          * this command for frontend exceptions.
2532          */
2533         if (cmd->transport_state & CMD_T_STOP) {
2534                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2535                          __func__, __LINE__, cmd->tag);
2536
2537                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2538
2539                 complete_all(&cmd->t_transport_stop_comp);
2540                 return 0;
2541         }
2542         cmd->transport_state &= ~CMD_T_ACTIVE;
2543         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2544
2545         ret = cmd->se_tfo->write_pending(cmd);
2546         if (ret)
2547                 goto queue_full;
2548
2549         return 0;
2550
2551 queue_full:
2552         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2553         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2554         return 0;
2555 }
2556 EXPORT_SYMBOL(transport_generic_new_cmd);
2557
2558 static void transport_write_pending_qf(struct se_cmd *cmd)
2559 {
2560         unsigned long flags;
2561         int ret;
2562         bool stop;
2563
2564         spin_lock_irqsave(&cmd->t_state_lock, flags);
2565         stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2566         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2567
2568         if (stop) {
2569                 pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2570                         __func__, __LINE__, cmd->tag);
2571                 complete_all(&cmd->t_transport_stop_comp);
2572                 return;
2573         }
2574
2575         ret = cmd->se_tfo->write_pending(cmd);
2576         if (ret) {
2577                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2578                          cmd);
2579                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2580         }
2581 }
2582
2583 static bool
2584 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2585                            unsigned long *flags);
2586
2587 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2588 {
2589         unsigned long flags;
2590
2591         spin_lock_irqsave(&cmd->t_state_lock, flags);
2592         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2593         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2594 }
2595
2596 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2597 {
2598         int ret = 0;
2599         bool aborted = false, tas = false;
2600
2601         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2602                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2603                         target_wait_free_cmd(cmd, &aborted, &tas);
2604
2605                 if (!aborted || tas)
2606                         ret = target_put_sess_cmd(cmd);
2607         } else {
2608                 if (wait_for_tasks)
2609                         target_wait_free_cmd(cmd, &aborted, &tas);
2610                 /*
2611                  * Handle WRITE failure case where transport_generic_new_cmd()
2612                  * has already added se_cmd to state_list, but fabric has
2613                  * failed command before I/O submission.
2614                  */
2615                 if (cmd->state_active)
2616                         target_remove_from_state_list(cmd);
2617
2618                 if (cmd->se_lun)
2619                         transport_lun_remove_cmd(cmd);
2620
2621                 if (!aborted || tas)
2622                         ret = target_put_sess_cmd(cmd);
2623         }
2624         /*
2625          * If the task has been internally aborted due to TMR ABORT_TASK
2626          * or LUN_RESET, target_core_tmr.c is responsible for performing
2627          * the remaining calls to target_put_sess_cmd(), and not the
2628          * callers of this function.
2629          */
2630         if (aborted) {
2631                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2632                 wait_for_completion(&cmd->cmd_wait_comp);
2633                 cmd->se_tfo->release_cmd(cmd);
2634                 ret = 1;
2635         }
2636         return ret;
2637 }
2638 EXPORT_SYMBOL(transport_generic_free_cmd);
2639
2640 /**
2641  * target_get_sess_cmd - Add command to active ->sess_cmd_list
2642  * @se_cmd:     command descriptor to add
2643  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2644  */
2645 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2646 {
2647         struct se_session *se_sess = se_cmd->se_sess;
2648         unsigned long flags;
2649         int ret = 0;
2650
2651         /*
2652          * Add a second kref if the fabric caller is expecting to handle
2653          * fabric acknowledgement that requires two target_put_sess_cmd()
2654          * invocations before se_cmd descriptor release.
2655          */
2656         if (ack_kref) {
2657                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2658                         return -EINVAL;
2659
2660                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2661         }
2662
2663         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2664         if (se_sess->sess_tearing_down) {
2665                 ret = -ESHUTDOWN;
2666                 goto out;
2667         }
2668         se_cmd->transport_state |= CMD_T_PRE_EXECUTE;
2669         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2670 out:
2671         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2672
2673         if (ret && ack_kref)
2674                 target_put_sess_cmd(se_cmd);
2675
2676         return ret;
2677 }
2678 EXPORT_SYMBOL(target_get_sess_cmd);
2679
2680 static void target_free_cmd_mem(struct se_cmd *cmd)
2681 {
2682         transport_free_pages(cmd);
2683
2684         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2685                 core_tmr_release_req(cmd->se_tmr_req);
2686         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2687                 kfree(cmd->t_task_cdb);
2688 }
2689
2690 static void target_release_cmd_kref(struct kref *kref)
2691 {
2692         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2693         struct se_session *se_sess = se_cmd->se_sess;
2694         unsigned long flags;
2695         bool fabric_stop;
2696
2697         if (se_sess) {
2698                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2699
2700                 spin_lock(&se_cmd->t_state_lock);
2701                 fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2702                               (se_cmd->transport_state & CMD_T_ABORTED);
2703                 spin_unlock(&se_cmd->t_state_lock);
2704
2705                 if (se_cmd->cmd_wait_set || fabric_stop) {
2706                         list_del_init(&se_cmd->se_cmd_list);
2707                         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2708                         target_free_cmd_mem(se_cmd);
2709                         complete(&se_cmd->cmd_wait_comp);
2710                         return;
2711                 }
2712                 list_del_init(&se_cmd->se_cmd_list);
2713                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2714         }
2715
2716         target_free_cmd_mem(se_cmd);
2717         se_cmd->se_tfo->release_cmd(se_cmd);
2718 }
2719
2720 /**
2721  * target_put_sess_cmd - decrease the command reference count
2722  * @se_cmd:     command to drop a reference from
2723  *
2724  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2725  * refcount to drop to zero. Returns zero otherwise.
2726  */
2727 int target_put_sess_cmd(struct se_cmd *se_cmd)
2728 {
2729         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2730 }
2731 EXPORT_SYMBOL(target_put_sess_cmd);
2732
2733 static const char *data_dir_name(enum dma_data_direction d)
2734 {
2735         switch (d) {
2736         case DMA_BIDIRECTIONAL: return "BIDI";
2737         case DMA_TO_DEVICE:     return "WRITE";
2738         case DMA_FROM_DEVICE:   return "READ";
2739         case DMA_NONE:          return "NONE";
2740         }
2741
2742         return "(?)";
2743 }
2744
2745 static const char *cmd_state_name(enum transport_state_table t)
2746 {
2747         switch (t) {
2748         case TRANSPORT_NO_STATE:        return "NO_STATE";
2749         case TRANSPORT_NEW_CMD:         return "NEW_CMD";
2750         case TRANSPORT_WRITE_PENDING:   return "WRITE_PENDING";
2751         case TRANSPORT_PROCESSING:      return "PROCESSING";
2752         case TRANSPORT_COMPLETE:        return "COMPLETE";
2753         case TRANSPORT_ISTATE_PROCESSING:
2754                                         return "ISTATE_PROCESSING";
2755         case TRANSPORT_COMPLETE_QF_WP:  return "COMPLETE_QF_WP";
2756         case TRANSPORT_COMPLETE_QF_OK:  return "COMPLETE_QF_OK";
2757         case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
2758         }
2759
2760         return "(?)";
2761 }
2762
2763 static void target_append_str(char **str, const char *txt)
2764 {
2765         char *prev = *str;
2766
2767         *str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
2768                 kstrdup(txt, GFP_ATOMIC);
2769         kfree(prev);
2770 }
2771
2772 /*
2773  * Convert a transport state bitmask into a string. The caller is
2774  * responsible for freeing the returned pointer.
2775  */
2776 static char *target_ts_to_str(u32 ts)
2777 {
2778         char *str = NULL;
2779
2780         if (ts & CMD_T_ABORTED)
2781                 target_append_str(&str, "aborted");
2782         if (ts & CMD_T_ACTIVE)
2783                 target_append_str(&str, "active");
2784         if (ts & CMD_T_COMPLETE)
2785                 target_append_str(&str, "complete");
2786         if (ts & CMD_T_SENT)
2787                 target_append_str(&str, "sent");
2788         if (ts & CMD_T_STOP)
2789                 target_append_str(&str, "stop");
2790         if (ts & CMD_T_FABRIC_STOP)
2791                 target_append_str(&str, "fabric_stop");
2792
2793         return str;
2794 }
2795
2796 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
2797 {
2798         switch (tmf) {
2799         case TMR_ABORT_TASK:            return "ABORT_TASK";
2800         case TMR_ABORT_TASK_SET:        return "ABORT_TASK_SET";
2801         case TMR_CLEAR_ACA:             return "CLEAR_ACA";
2802         case TMR_CLEAR_TASK_SET:        return "CLEAR_TASK_SET";
2803         case TMR_LUN_RESET:             return "LUN_RESET";
2804         case TMR_TARGET_WARM_RESET:     return "TARGET_WARM_RESET";
2805         case TMR_TARGET_COLD_RESET:     return "TARGET_COLD_RESET";
2806         case TMR_UNKNOWN:               break;
2807         }
2808         return "(?)";
2809 }
2810
2811 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
2812 {
2813         char *ts_str = target_ts_to_str(cmd->transport_state);
2814         const u8 *cdb = cmd->t_task_cdb;
2815         struct se_tmr_req *tmf = cmd->se_tmr_req;
2816
2817         if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2818                 pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
2819                          pfx, cdb[0], cdb[1], cmd->tag,
2820                          data_dir_name(cmd->data_direction),
2821                          cmd->se_tfo->get_cmd_state(cmd),
2822                          cmd_state_name(cmd->t_state), cmd->data_length,
2823                          kref_read(&cmd->cmd_kref), ts_str);
2824         } else {
2825                 pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
2826                          pfx, target_tmf_name(tmf->function), cmd->tag,
2827                          tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
2828                          cmd_state_name(cmd->t_state),
2829                          kref_read(&cmd->cmd_kref), ts_str);
2830         }
2831         kfree(ts_str);
2832 }
2833 EXPORT_SYMBOL(target_show_cmd);
2834
2835 /**
2836  * target_sess_cmd_list_set_waiting - Flag all commands in
2837  *         sess_cmd_list to complete cmd_wait_comp.  Set
2838  *         sess_tearing_down so no more commands are queued.
2839  * @se_sess:    session to flag
2840  */
2841 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2842 {
2843         struct se_cmd *se_cmd, *tmp_cmd;
2844         unsigned long flags;
2845         int rc;
2846
2847         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2848         if (se_sess->sess_tearing_down) {
2849                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2850                 return;
2851         }
2852         se_sess->sess_tearing_down = 1;
2853         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2854
2855         list_for_each_entry_safe(se_cmd, tmp_cmd,
2856                                  &se_sess->sess_wait_list, se_cmd_list) {
2857                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2858                 if (rc) {
2859                         se_cmd->cmd_wait_set = 1;
2860                         spin_lock(&se_cmd->t_state_lock);
2861                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2862                         spin_unlock(&se_cmd->t_state_lock);
2863                 } else
2864                         list_del_init(&se_cmd->se_cmd_list);
2865         }
2866
2867         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2868 }
2869 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2870
2871 /**
2872  * target_wait_for_sess_cmds - Wait for outstanding descriptors
2873  * @se_sess:    session to wait for active I/O
2874  */
2875 void target_wait_for_sess_cmds(struct se_session *se_sess)
2876 {
2877         struct se_cmd *se_cmd, *tmp_cmd;
2878         unsigned long flags;
2879         bool tas;
2880
2881         list_for_each_entry_safe(se_cmd, tmp_cmd,
2882                                 &se_sess->sess_wait_list, se_cmd_list) {
2883                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2884                         " %d\n", se_cmd, se_cmd->t_state,
2885                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2886
2887                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2888                 tas = (se_cmd->transport_state & CMD_T_TAS);
2889                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2890
2891                 if (!target_put_sess_cmd(se_cmd)) {
2892                         if (tas)
2893                                 target_put_sess_cmd(se_cmd);
2894                 }
2895
2896                 wait_for_completion(&se_cmd->cmd_wait_comp);
2897                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2898                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2899                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2900
2901                 se_cmd->se_tfo->release_cmd(se_cmd);
2902         }
2903
2904         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2905         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2906         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2907
2908 }
2909 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2910
2911 static void target_lun_confirm(struct percpu_ref *ref)
2912 {
2913         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2914
2915         complete(&lun->lun_ref_comp);
2916 }
2917
2918 void transport_clear_lun_ref(struct se_lun *lun)
2919 {
2920         /*
2921          * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2922          * the initial reference and schedule confirm kill to be
2923          * executed after one full RCU grace period has completed.
2924          */
2925         percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2926         /*
2927          * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2928          * to call target_lun_confirm after lun->lun_ref has been marked
2929          * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2930          * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2931          * fails for all new incoming I/O.
2932          */
2933         wait_for_completion(&lun->lun_ref_comp);
2934         /*
2935          * The second completion waits for percpu_ref_put_many() to
2936          * invoke ->release() after lun->lun_ref has switched to
2937          * atomic_t mode, and lun->lun_ref.count has reached zero.
2938          *
2939          * At this point all target-core lun->lun_ref references have
2940          * been dropped via transport_lun_remove_cmd(), and it's safe
2941          * to proceed with the remaining LUN shutdown.
2942          */
2943         wait_for_completion(&lun->lun_shutdown_comp);
2944 }
2945
2946 static bool
2947 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2948                            bool *aborted, bool *tas, unsigned long *flags)
2949         __releases(&cmd->t_state_lock)
2950         __acquires(&cmd->t_state_lock)
2951 {
2952
2953         assert_spin_locked(&cmd->t_state_lock);
2954         WARN_ON_ONCE(!irqs_disabled());
2955
2956         if (fabric_stop)
2957                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2958
2959         if (cmd->transport_state & CMD_T_ABORTED)
2960                 *aborted = true;
2961
2962         if (cmd->transport_state & CMD_T_TAS)
2963                 *tas = true;
2964
2965         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2966             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2967                 return false;
2968
2969         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2970             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2971                 return false;
2972
2973         if (!(cmd->transport_state & CMD_T_ACTIVE))
2974                 return false;
2975
2976         if (fabric_stop && *aborted)
2977                 return false;
2978
2979         cmd->transport_state |= CMD_T_STOP;
2980
2981         target_show_cmd("wait_for_tasks: Stopping ", cmd);
2982
2983         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2984
2985         while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
2986                                             180 * HZ))
2987                 target_show_cmd("wait for tasks: ", cmd);
2988
2989         spin_lock_irqsave(&cmd->t_state_lock, *flags);
2990         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2991
2992         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2993                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2994
2995         return true;
2996 }
2997
2998 /**
2999  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3000  * @cmd: command to wait on
3001  */
3002 bool transport_wait_for_tasks(struct se_cmd *cmd)
3003 {
3004         unsigned long flags;
3005         bool ret, aborted = false, tas = false;
3006
3007         spin_lock_irqsave(&cmd->t_state_lock, flags);
3008         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3009         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3010
3011         return ret;
3012 }
3013 EXPORT_SYMBOL(transport_wait_for_tasks);
3014
3015 struct sense_info {
3016         u8 key;
3017         u8 asc;
3018         u8 ascq;
3019         bool add_sector_info;
3020 };
3021
3022 static const struct sense_info sense_info_table[] = {
3023         [TCM_NO_SENSE] = {
3024                 .key = NOT_READY
3025         },
3026         [TCM_NON_EXISTENT_LUN] = {
3027                 .key = ILLEGAL_REQUEST,
3028                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3029         },
3030         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
3031                 .key = ILLEGAL_REQUEST,
3032                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3033         },
3034         [TCM_SECTOR_COUNT_TOO_MANY] = {
3035                 .key = ILLEGAL_REQUEST,
3036                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3037         },
3038         [TCM_UNKNOWN_MODE_PAGE] = {
3039                 .key = ILLEGAL_REQUEST,
3040                 .asc = 0x24, /* INVALID FIELD IN CDB */
3041         },
3042         [TCM_CHECK_CONDITION_ABORT_CMD] = {
3043                 .key = ABORTED_COMMAND,
3044                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3045                 .ascq = 0x03,
3046         },
3047         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
3048                 .key = ABORTED_COMMAND,
3049                 .asc = 0x0c, /* WRITE ERROR */
3050                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3051         },
3052         [TCM_INVALID_CDB_FIELD] = {
3053                 .key = ILLEGAL_REQUEST,
3054                 .asc = 0x24, /* INVALID FIELD IN CDB */
3055         },
3056         [TCM_INVALID_PARAMETER_LIST] = {
3057                 .key = ILLEGAL_REQUEST,
3058                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3059         },
3060         [TCM_TOO_MANY_TARGET_DESCS] = {
3061                 .key = ILLEGAL_REQUEST,
3062                 .asc = 0x26,
3063                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3064         },
3065         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3066                 .key = ILLEGAL_REQUEST,
3067                 .asc = 0x26,
3068                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3069         },
3070         [TCM_TOO_MANY_SEGMENT_DESCS] = {
3071                 .key = ILLEGAL_REQUEST,
3072                 .asc = 0x26,
3073                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3074         },
3075         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3076                 .key = ILLEGAL_REQUEST,
3077                 .asc = 0x26,
3078                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3079         },
3080         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3081                 .key = ILLEGAL_REQUEST,
3082                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3083         },
3084         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3085                 .key = ILLEGAL_REQUEST,
3086                 .asc = 0x0c, /* WRITE ERROR */
3087                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3088         },
3089         [TCM_SERVICE_CRC_ERROR] = {
3090                 .key = ABORTED_COMMAND,
3091                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3092                 .ascq = 0x05, /* N/A */
3093         },
3094         [TCM_SNACK_REJECTED] = {
3095                 .key = ABORTED_COMMAND,
3096                 .asc = 0x11, /* READ ERROR */
3097                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3098         },
3099         [TCM_WRITE_PROTECTED] = {
3100                 .key = DATA_PROTECT,
3101                 .asc = 0x27, /* WRITE PROTECTED */
3102         },
3103         [TCM_ADDRESS_OUT_OF_RANGE] = {
3104                 .key = ILLEGAL_REQUEST,
3105                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3106         },
3107         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3108                 .key = UNIT_ATTENTION,
3109         },
3110         [TCM_CHECK_CONDITION_NOT_READY] = {
3111                 .key = NOT_READY,
3112         },
3113         [TCM_MISCOMPARE_VERIFY] = {
3114                 .key = MISCOMPARE,
3115                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3116                 .ascq = 0x00,
3117         },
3118         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3119                 .key = ABORTED_COMMAND,
3120                 .asc = 0x10,
3121                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3122                 .add_sector_info = true,
3123         },
3124         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3125                 .key = ABORTED_COMMAND,
3126                 .asc = 0x10,
3127                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3128                 .add_sector_info = true,
3129         },
3130         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3131                 .key = ABORTED_COMMAND,
3132                 .asc = 0x10,
3133                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3134                 .add_sector_info = true,
3135         },
3136         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3137                 .key = COPY_ABORTED,
3138                 .asc = 0x0d,
3139                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3140
3141         },
3142         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3143                 /*
3144                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
3145                  * Solaris initiators.  Returning NOT READY instead means the
3146                  * operations will be retried a finite number of times and we
3147                  * can survive intermittent errors.
3148                  */
3149                 .key = NOT_READY,
3150                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3151         },
3152         [TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3153                 /*
3154                  * From spc4r22 section5.7.7,5.7.8
3155                  * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3156                  * or a REGISTER AND IGNORE EXISTING KEY service action or
3157                  * REGISTER AND MOVE service actionis attempted,
3158                  * but there are insufficient device server resources to complete the
3159                  * operation, then the command shall be terminated with CHECK CONDITION
3160                  * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3161                  * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3162                  */
3163                 .key = ILLEGAL_REQUEST,
3164                 .asc = 0x55,
3165                 .ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3166         },
3167 };
3168
3169 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3170 {
3171         const struct sense_info *si;
3172         u8 *buffer = cmd->sense_buffer;
3173         int r = (__force int)reason;
3174         u8 asc, ascq;
3175         bool desc_format = target_sense_desc_format(cmd->se_dev);
3176
3177         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
3178                 si = &sense_info_table[r];
3179         else
3180                 si = &sense_info_table[(__force int)
3181                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3182
3183         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3184                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
3185                 WARN_ON_ONCE(asc == 0);
3186         } else if (si->asc == 0) {
3187                 WARN_ON_ONCE(cmd->scsi_asc == 0);
3188                 asc = cmd->scsi_asc;
3189                 ascq = cmd->scsi_ascq;
3190         } else {
3191                 asc = si->asc;
3192                 ascq = si->ascq;
3193         }
3194
3195         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
3196         if (si->add_sector_info)
3197                 return scsi_set_sense_information(buffer,
3198                                                   cmd->scsi_sense_length,
3199                                                   cmd->bad_sector);
3200
3201         return 0;
3202 }
3203
3204 int
3205 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3206                 sense_reason_t reason, int from_transport)
3207 {
3208         unsigned long flags;
3209
3210         spin_lock_irqsave(&cmd->t_state_lock, flags);
3211         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3212                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3213                 return 0;
3214         }
3215         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3216         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3217
3218         if (!from_transport) {
3219                 int rc;
3220
3221                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3222                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3223                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3224                 rc = translate_sense_reason(cmd, reason);
3225                 if (rc)
3226                         return rc;
3227         }
3228
3229         trace_target_cmd_complete(cmd);
3230         return cmd->se_tfo->queue_status(cmd);
3231 }
3232 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3233
3234 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3235         __releases(&cmd->t_state_lock)
3236         __acquires(&cmd->t_state_lock)
3237 {
3238         int ret;
3239
3240         assert_spin_locked(&cmd->t_state_lock);
3241         WARN_ON_ONCE(!irqs_disabled());
3242
3243         if (!(cmd->transport_state & CMD_T_ABORTED))
3244                 return 0;
3245         /*
3246          * If cmd has been aborted but either no status is to be sent or it has
3247          * already been sent, just return
3248          */
3249         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3250                 if (send_status)
3251                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3252                 return 1;
3253         }
3254
3255         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3256                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3257
3258         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3259         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3260         trace_target_cmd_complete(cmd);
3261
3262         spin_unlock_irq(&cmd->t_state_lock);
3263         ret = cmd->se_tfo->queue_status(cmd);
3264         if (ret)
3265                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3266         spin_lock_irq(&cmd->t_state_lock);
3267
3268         return 1;
3269 }
3270
3271 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3272 {
3273         int ret;
3274
3275         spin_lock_irq(&cmd->t_state_lock);
3276         ret = __transport_check_aborted_status(cmd, send_status);
3277         spin_unlock_irq(&cmd->t_state_lock);
3278
3279         return ret;
3280 }
3281 EXPORT_SYMBOL(transport_check_aborted_status);
3282
3283 void transport_send_task_abort(struct se_cmd *cmd)
3284 {
3285         unsigned long flags;
3286         int ret;
3287
3288         spin_lock_irqsave(&cmd->t_state_lock, flags);
3289         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3290                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3291                 return;
3292         }
3293         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3294
3295         /*
3296          * If there are still expected incoming fabric WRITEs, we wait
3297          * until until they have completed before sending a TASK_ABORTED
3298          * response.  This response with TASK_ABORTED status will be
3299          * queued back to fabric module by transport_check_aborted_status().
3300          */
3301         if (cmd->data_direction == DMA_TO_DEVICE) {
3302                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3303                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3304                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3305                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3306                                 goto send_abort;
3307                         }
3308                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3309                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3310                         return;
3311                 }
3312         }
3313 send_abort:
3314         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3315
3316         transport_lun_remove_cmd(cmd);
3317
3318         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3319                  cmd->t_task_cdb[0], cmd->tag);
3320
3321         trace_target_cmd_complete(cmd);
3322         ret = cmd->se_tfo->queue_status(cmd);
3323         if (ret)
3324                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3325 }
3326
3327 static void target_tmr_work(struct work_struct *work)
3328 {
3329         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3330         struct se_device *dev = cmd->se_dev;
3331         struct se_tmr_req *tmr = cmd->se_tmr_req;
3332         unsigned long flags;
3333         int ret;
3334
3335         spin_lock_irqsave(&cmd->t_state_lock, flags);
3336         if (cmd->transport_state & CMD_T_ABORTED) {
3337                 tmr->response = TMR_FUNCTION_REJECTED;
3338                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3339                 goto check_stop;
3340         }
3341         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3342
3343         switch (tmr->function) {
3344         case TMR_ABORT_TASK:
3345                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3346                 break;
3347         case TMR_ABORT_TASK_SET:
3348         case TMR_CLEAR_ACA:
3349         case TMR_CLEAR_TASK_SET:
3350                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3351                 break;
3352         case TMR_LUN_RESET:
3353                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3354                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3355                                          TMR_FUNCTION_REJECTED;
3356                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3357                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3358                                                cmd->orig_fe_lun, 0x29,
3359                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3360                 }
3361                 break;
3362         case TMR_TARGET_WARM_RESET:
3363                 tmr->response = TMR_FUNCTION_REJECTED;
3364                 break;
3365         case TMR_TARGET_COLD_RESET:
3366                 tmr->response = TMR_FUNCTION_REJECTED;
3367                 break;
3368         default:
3369                 pr_err("Unknown TMR function: 0x%02x.\n",
3370                                 tmr->function);
3371                 tmr->response = TMR_FUNCTION_REJECTED;
3372                 break;
3373         }
3374
3375         spin_lock_irqsave(&cmd->t_state_lock, flags);
3376         if (cmd->transport_state & CMD_T_ABORTED) {
3377                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3378                 goto check_stop;
3379         }
3380         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3381
3382         cmd->se_tfo->queue_tm_rsp(cmd);
3383
3384 check_stop:
3385         transport_lun_remove_cmd(cmd);
3386         transport_cmd_check_stop_to_fabric(cmd);
3387 }
3388
3389 int transport_generic_handle_tmr(
3390         struct se_cmd *cmd)
3391 {
3392         unsigned long flags;
3393         bool aborted = false;
3394
3395         spin_lock_irqsave(&cmd->t_state_lock, flags);
3396         if (cmd->transport_state & CMD_T_ABORTED) {
3397                 aborted = true;
3398         } else {
3399                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3400                 cmd->transport_state |= CMD_T_ACTIVE;
3401         }
3402         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3403
3404         if (aborted) {
3405                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3406                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3407                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3408                 transport_lun_remove_cmd(cmd);
3409                 transport_cmd_check_stop_to_fabric(cmd);
3410                 return 0;
3411         }
3412
3413         INIT_WORK(&cmd->work, target_tmr_work);
3414         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3415         return 0;
3416 }
3417 EXPORT_SYMBOL(transport_generic_handle_tmr);
3418
3419 bool
3420 target_check_wce(struct se_device *dev)
3421 {
3422         bool wce = false;
3423
3424         if (dev->transport->get_write_cache)
3425                 wce = dev->transport->get_write_cache(dev);
3426         else if (dev->dev_attrib.emulate_write_cache > 0)
3427                 wce = true;
3428
3429         return wce;
3430 }
3431
3432 bool
3433 target_check_fua(struct se_device *dev)
3434 {
3435         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3436 }