drivers/target/target_core_transport.c

   1 /*******************************************************************************
   2  * Filename:  target_core_transport.c
   3  *
   4  * This file contains the Generic Target Engine Core.
   5  *
   6  * (c) Copyright 2002-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/net.h>
  27 #include <linux/delay.h>
  28 #include <linux/string.h>
  29 #include <linux/timer.h>
  30 #include <linux/slab.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/kthread.h>
  33 #include <linux/in.h>
  34 #include <linux/cdrom.h>
  35 #include <linux/module.h>
  36 #include <linux/ratelimit.h>
  37 #include <linux/vmalloc.h>
  38 #include <asm/unaligned.h>
  39 #include <net/sock.h>
  40 #include <net/tcp.h>
  41 #include <scsi/scsi_proto.h>
  42 #include <scsi/scsi_common.h>
  43
  44 #include <target/target_core_base.h>
  45 #include <target/target_core_backend.h>
  46 #include <target/target_core_fabric.h>
  47
  48 #include "target_core_internal.h"
  49 #include "target_core_alua.h"
  50 #include "target_core_pr.h"
  51 #include "target_core_ua.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/target.h>
  55
  56 static struct workqueue_struct *target_completion_wq;
  57 static struct kmem_cache *se_sess_cache;
  58 struct kmem_cache *se_ua_cache;
  59 struct kmem_cache *t10_pr_reg_cache;
  60 struct kmem_cache *t10_alua_lu_gp_cache;
  61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  63 struct kmem_cache *t10_alua_lba_map_cache;
  64 struct kmem_cache *t10_alua_lba_map_mem_cache;
  65
  66 static void transport_complete_task_attr(struct se_cmd *cmd);
  67 static void transport_handle_queue_full(struct se_cmd *cmd,
  68                 struct se_device *dev);
  69 static int transport_put_cmd(struct se_cmd *cmd);
  70 static void target_complete_ok_work(struct work_struct *work);
  71
  72 int init_se_kmem_caches(void)
  73 {
  74         se_sess_cache = kmem_cache_create("se_sess_cache",
  75                         sizeof(struct se_session), __alignof__(struct se_session),
  76                         0, NULL);
  77         if (!se_sess_cache) {
  78                 pr_err("kmem_cache_create() for struct se_session"
  79                                 " failed\n");
  80                 goto out;
  81         }
  82         se_ua_cache = kmem_cache_create("se_ua_cache",
  83                         sizeof(struct se_ua), __alignof__(struct se_ua),
  84                         0, NULL);
  85         if (!se_ua_cache) {
  86                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  87                 goto out_free_sess_cache;
  88         }
  89         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  90                         sizeof(struct t10_pr_registration),
  91                         __alignof__(struct t10_pr_registration), 0, NULL);
  92         if (!t10_pr_reg_cache) {
  93                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  94                                 " failed\n");
  95                 goto out_free_ua_cache;
  96         }
  97         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  98                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  99                         0, NULL);
 100         if (!t10_alua_lu_gp_cache) {
 101                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 102                                 " failed\n");
 103                 goto out_free_pr_reg_cache;
 104         }
 105         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 106                         sizeof(struct t10_alua_lu_gp_member),
 107                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 108         if (!t10_alua_lu_gp_mem_cache) {
 109                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 110                                 "cache failed\n");
 111                 goto out_free_lu_gp_cache;
 112         }
 113         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 114                         sizeof(struct t10_alua_tg_pt_gp),
 115                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 116         if (!t10_alua_tg_pt_gp_cache) {
 117                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 118                                 "cache failed\n");
 119                 goto out_free_lu_gp_mem_cache;
 120         }
 121         t10_alua_lba_map_cache = kmem_cache_create(
 122                         "t10_alua_lba_map_cache",
 123                         sizeof(struct t10_alua_lba_map),
 124                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 125         if (!t10_alua_lba_map_cache) {
 126                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 127                                 "cache failed\n");
 128                 goto out_free_tg_pt_gp_cache;
 129         }
 130         t10_alua_lba_map_mem_cache = kmem_cache_create(
 131                         "t10_alua_lba_map_mem_cache",
 132                         sizeof(struct t10_alua_lba_map_member),
 133                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 134         if (!t10_alua_lba_map_mem_cache) {
 135                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 136                                 "cache failed\n");
 137                 goto out_free_lba_map_cache;
 138         }
 139
 140         target_completion_wq = alloc_workqueue("target_completion",
 141                                                WQ_MEM_RECLAIM, 0);
 142         if (!target_completion_wq)
 143                 goto out_free_lba_map_mem_cache;
 144
 145         return 0;
 146
 147 out_free_lba_map_mem_cache:
 148         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 149 out_free_lba_map_cache:
 150         kmem_cache_destroy(t10_alua_lba_map_cache);
 151 out_free_tg_pt_gp_cache:
 152         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 153 out_free_lu_gp_mem_cache:
 154         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 155 out_free_lu_gp_cache:
 156         kmem_cache_destroy(t10_alua_lu_gp_cache);
 157 out_free_pr_reg_cache:
 158         kmem_cache_destroy(t10_pr_reg_cache);
 159 out_free_ua_cache:
 160         kmem_cache_destroy(se_ua_cache);
 161 out_free_sess_cache:
 162         kmem_cache_destroy(se_sess_cache);
 163 out:
 164         return -ENOMEM;
 165 }
 166
 167 void release_se_kmem_caches(void)
 168 {
 169         destroy_workqueue(target_completion_wq);
 170         kmem_cache_destroy(se_sess_cache);
 171         kmem_cache_destroy(se_ua_cache);
 172         kmem_cache_destroy(t10_pr_reg_cache);
 173         kmem_cache_destroy(t10_alua_lu_gp_cache);
 174         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 175         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 176         kmem_cache_destroy(t10_alua_lba_map_cache);
 177         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 178 }
 179
 180 /* This code ensures unique mib indexes are handed out. */
 181 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 182 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 183
 184 /*
 185  * Allocate a new row index for the entry type specified
 186  */
 187 u32 scsi_get_new_index(scsi_index_t type)
 188 {
 189         u32 new_index;
 190
 191         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 192
 193         spin_lock(&scsi_mib_index_lock);
 194         new_index = ++scsi_mib_index[type];
 195         spin_unlock(&scsi_mib_index_lock);
 196
 197         return new_index;
 198 }
 199
 200 void transport_subsystem_check_init(void)
 201 {
 202         int ret;
 203         static int sub_api_initialized;
 204
 205         if (sub_api_initialized)
 206                 return;
 207
 208         ret = request_module("target_core_iblock");
 209         if (ret != 0)
 210                 pr_err("Unable to load target_core_iblock\n");
 211
 212         ret = request_module("target_core_file");
 213         if (ret != 0)
 214                 pr_err("Unable to load target_core_file\n");
 215
 216         ret = request_module("target_core_pscsi");
 217         if (ret != 0)
 218                 pr_err("Unable to load target_core_pscsi\n");
 219
 220         ret = request_module("target_core_user");
 221         if (ret != 0)
 222                 pr_err("Unable to load target_core_user\n");
 223
 224         sub_api_initialized = 1;
 225 }
 226
 227 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
 228 {
 229         struct se_session *se_sess;
 230
 231         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 232         if (!se_sess) {
 233                 pr_err("Unable to allocate struct se_session from"
 234                                 " se_sess_cache\n");
 235                 return ERR_PTR(-ENOMEM);
 236         }
 237         INIT_LIST_HEAD(&se_sess->sess_list);
 238         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 239         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 240         INIT_LIST_HEAD(&se_sess->sess_wait_list);
 241         spin_lock_init(&se_sess->sess_cmd_lock);
 242         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 = kzalloc(tag_num * tag_size,
 254                                         GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
 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(&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(&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 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 654 {
 655         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 656
 657         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 658                 transport_lun_remove_cmd(cmd);
 659         /*
 660          * Allow the fabric driver to unmap any resources before
 661          * releasing the descriptor via TFO->release_cmd()
 662          */
 663         if (remove)
 664                 cmd->se_tfo->aborted_task(cmd);
 665
 666         if (transport_cmd_check_stop_to_fabric(cmd))
 667                 return;
 668         if (remove && ack_kref)
 669                 transport_put_cmd(cmd);
 670 }
 671
 672 static void target_complete_failure_work(struct work_struct *work)
 673 {
 674         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 675
 676         transport_generic_request_failure(cmd,
 677                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 678 }
 679
 680 /*
 681  * Used when asking transport to copy Sense Data from the underlying
 682  * Linux/SCSI struct scsi_cmnd
 683  */
 684 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 685 {
 686         struct se_device *dev = cmd->se_dev;
 687
 688         WARN_ON(!cmd->se_lun);
 689
 690         if (!dev)
 691                 return NULL;
 692
 693         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 694                 return NULL;
 695
 696         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 697
 698         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 699                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 700         return cmd->sense_buffer;
 701 }
 702
 703 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 704 {
 705         struct se_device *dev = cmd->se_dev;
 706         int success = scsi_status == GOOD;
 707         unsigned long flags;
 708
 709         cmd->scsi_status = scsi_status;
 710
 711
 712         spin_lock_irqsave(&cmd->t_state_lock, flags);
 713
 714         if (dev && dev->transport->transport_complete) {
 715                 dev->transport->transport_complete(cmd,
 716                                 cmd->t_data_sg,
 717                                 transport_get_sense_buffer(cmd));
 718                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 719                         success = 1;
 720         }
 721
 722         /*
 723          * Check for case where an explicit ABORT_TASK has been received
 724          * and transport_wait_for_tasks() will be waiting for completion..
 725          */
 726         if (cmd->transport_state & CMD_T_ABORTED ||
 727             cmd->transport_state & CMD_T_STOP) {
 728                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 729                 complete_all(&cmd->t_transport_stop_comp);
 730                 return;
 731         } else if (!success) {
 732                 INIT_WORK(&cmd->work, target_complete_failure_work);
 733         } else {
 734                 INIT_WORK(&cmd->work, target_complete_ok_work);
 735         }
 736
 737         cmd->t_state = TRANSPORT_COMPLETE;
 738         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 739         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 740
 741         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 742                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 743         else
 744                 queue_work(target_completion_wq, &cmd->work);
 745 }
 746 EXPORT_SYMBOL(target_complete_cmd);
 747
 748 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 749 {
 750         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 751                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 752                         cmd->residual_count += cmd->data_length - length;
 753                 } else {
 754                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 755                         cmd->residual_count = cmd->data_length - length;
 756                 }
 757
 758                 cmd->data_length = length;
 759         }
 760
 761         target_complete_cmd(cmd, scsi_status);
 762 }
 763 EXPORT_SYMBOL(target_complete_cmd_with_length);
 764
 765 static void target_add_to_state_list(struct se_cmd *cmd)
 766 {
 767         struct se_device *dev = cmd->se_dev;
 768         unsigned long flags;
 769
 770         spin_lock_irqsave(&dev->execute_task_lock, flags);
 771         if (!cmd->state_active) {
 772                 list_add_tail(&cmd->state_list, &dev->state_list);
 773                 cmd->state_active = true;
 774         }
 775         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 776 }
 777
 778 /*
 779  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 780  */
 781 static void transport_write_pending_qf(struct se_cmd *cmd);
 782 static void transport_complete_qf(struct se_cmd *cmd);
 783
 784 void target_qf_do_work(struct work_struct *work)
 785 {
 786         struct se_device *dev = container_of(work, struct se_device,
 787                                         qf_work_queue);
 788         LIST_HEAD(qf_cmd_list);
 789         struct se_cmd *cmd, *cmd_tmp;
 790
 791         spin_lock_irq(&dev->qf_cmd_lock);
 792         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 793         spin_unlock_irq(&dev->qf_cmd_lock);
 794
 795         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 796                 list_del(&cmd->se_qf_node);
 797                 atomic_dec_mb(&dev->dev_qf_count);
 798
 799                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 800                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 801                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 802                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 803                         : "UNKNOWN");
 804
 805                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 806                         transport_write_pending_qf(cmd);
 807                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 808                         transport_complete_qf(cmd);
 809         }
 810 }
 811
 812 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 813 {
 814         switch (cmd->data_direction) {
 815         case DMA_NONE:
 816                 return "NONE";
 817         case DMA_FROM_DEVICE:
 818                 return "READ";
 819         case DMA_TO_DEVICE:
 820                 return "WRITE";
 821         case DMA_BIDIRECTIONAL:
 822                 return "BIDI";
 823         default:
 824                 break;
 825         }
 826
 827         return "UNKNOWN";
 828 }
 829
 830 void transport_dump_dev_state(
 831         struct se_device *dev,
 832         char *b,
 833         int *bl)
 834 {
 835         *bl += sprintf(b + *bl, "Status: ");
 836         if (dev->export_count)
 837                 *bl += sprintf(b + *bl, "ACTIVATED");
 838         else
 839                 *bl += sprintf(b + *bl, "DEACTIVATED");
 840
 841         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 842         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 843                 dev->dev_attrib.block_size,
 844                 dev->dev_attrib.hw_max_sectors);
 845         *bl += sprintf(b + *bl, "        ");
 846 }
 847
 848 void transport_dump_vpd_proto_id(
 849         struct t10_vpd *vpd,
 850         unsigned char *p_buf,
 851         int p_buf_len)
 852 {
 853         unsigned char buf[VPD_TMP_BUF_SIZE];
 854         int len;
 855
 856         memset(buf, 0, VPD_TMP_BUF_SIZE);
 857         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 858
 859         switch (vpd->protocol_identifier) {
 860         case 0x00:
 861                 sprintf(buf+len, "Fibre Channel\n");
 862                 break;
 863         case 0x10:
 864                 sprintf(buf+len, "Parallel SCSI\n");
 865                 break;
 866         case 0x20:
 867                 sprintf(buf+len, "SSA\n");
 868                 break;
 869         case 0x30:
 870                 sprintf(buf+len, "IEEE 1394\n");
 871                 break;
 872         case 0x40:
 873                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 874                                 " Protocol\n");
 875                 break;
 876         case 0x50:
 877                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 878                 break;
 879         case 0x60:
 880                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 881                 break;
 882         case 0x70:
 883                 sprintf(buf+len, "Automation/Drive Interface Transport"
 884                                 " Protocol\n");
 885                 break;
 886         case 0x80:
 887                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 888                 break;
 889         default:
 890                 sprintf(buf+len, "Unknown 0x%02x\n",
 891                                 vpd->protocol_identifier);
 892                 break;
 893         }
 894
 895         if (p_buf)
 896                 strncpy(p_buf, buf, p_buf_len);
 897         else
 898                 pr_debug("%s", buf);
 899 }
 900
 901 void
 902 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 903 {
 904         /*
 905          * Check if the Protocol Identifier Valid (PIV) bit is set..
 906          *
 907          * from spc3r23.pdf section 7.5.1
 908          */
 909          if (page_83[1] & 0x80) {
 910                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 911                 vpd->protocol_identifier_set = 1;
 912                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 913         }
 914 }
 915 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 916
 917 int transport_dump_vpd_assoc(
 918         struct t10_vpd *vpd,
 919         unsigned char *p_buf,
 920         int p_buf_len)
 921 {
 922         unsigned char buf[VPD_TMP_BUF_SIZE];
 923         int ret = 0;
 924         int len;
 925
 926         memset(buf, 0, VPD_TMP_BUF_SIZE);
 927         len = sprintf(buf, "T10 VPD Identifier Association: ");
 928
 929         switch (vpd->association) {
 930         case 0x00:
 931                 sprintf(buf+len, "addressed logical unit\n");
 932                 break;
 933         case 0x10:
 934                 sprintf(buf+len, "target port\n");
 935                 break;
 936         case 0x20:
 937                 sprintf(buf+len, "SCSI target device\n");
 938                 break;
 939         default:
 940                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 941                 ret = -EINVAL;
 942                 break;
 943         }
 944
 945         if (p_buf)
 946                 strncpy(p_buf, buf, p_buf_len);
 947         else
 948                 pr_debug("%s", buf);
 949
 950         return ret;
 951 }
 952
 953 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 954 {
 955         /*
 956          * The VPD identification association..
 957          *
 958          * from spc3r23.pdf Section 7.6.3.1 Table 297
 959          */
 960         vpd->association = (page_83[1] & 0x30);
 961         return transport_dump_vpd_assoc(vpd, NULL, 0);
 962 }
 963 EXPORT_SYMBOL(transport_set_vpd_assoc);
 964
 965 int transport_dump_vpd_ident_type(
 966         struct t10_vpd *vpd,
 967         unsigned char *p_buf,
 968         int p_buf_len)
 969 {
 970         unsigned char buf[VPD_TMP_BUF_SIZE];
 971         int ret = 0;
 972         int len;
 973
 974         memset(buf, 0, VPD_TMP_BUF_SIZE);
 975         len = sprintf(buf, "T10 VPD Identifier Type: ");
 976
 977         switch (vpd->device_identifier_type) {
 978         case 0x00:
 979                 sprintf(buf+len, "Vendor specific\n");
 980                 break;
 981         case 0x01:
 982                 sprintf(buf+len, "T10 Vendor ID based\n");
 983                 break;
 984         case 0x02:
 985                 sprintf(buf+len, "EUI-64 based\n");
 986                 break;
 987         case 0x03:
 988                 sprintf(buf+len, "NAA\n");
 989                 break;
 990         case 0x04:
 991                 sprintf(buf+len, "Relative target port identifier\n");
 992                 break;
 993         case 0x08:
 994                 sprintf(buf+len, "SCSI name string\n");
 995                 break;
 996         default:
 997                 sprintf(buf+len, "Unsupported: 0x%02x\n",
 998                                 vpd->device_identifier_type);
 999                 ret = -EINVAL;
1000                 break;
1001         }
1002
1003         if (p_buf) {
1004                 if (p_buf_len < strlen(buf)+1)
1005                         return -EINVAL;
1006                 strncpy(p_buf, buf, p_buf_len);
1007         } else {
1008                 pr_debug("%s", buf);
1009         }
1010
1011         return ret;
1012 }
1013
1014 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1015 {
1016         /*
1017          * The VPD identifier type..
1018          *
1019          * from spc3r23.pdf Section 7.6.3.1 Table 298
1020          */
1021         vpd->device_identifier_type = (page_83[1] & 0x0f);
1022         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1023 }
1024 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1025
1026 int transport_dump_vpd_ident(
1027         struct t10_vpd *vpd,
1028         unsigned char *p_buf,
1029         int p_buf_len)
1030 {
1031         unsigned char buf[VPD_TMP_BUF_SIZE];
1032         int ret = 0;
1033
1034         memset(buf, 0, VPD_TMP_BUF_SIZE);
1035
1036         switch (vpd->device_identifier_code_set) {
1037         case 0x01: /* Binary */
1038                 snprintf(buf, sizeof(buf),
1039                         "T10 VPD Binary Device Identifier: %s\n",
1040                         &vpd->device_identifier[0]);
1041                 break;
1042         case 0x02: /* ASCII */
1043                 snprintf(buf, sizeof(buf),
1044                         "T10 VPD ASCII Device Identifier: %s\n",
1045                         &vpd->device_identifier[0]);
1046                 break;
1047         case 0x03: /* UTF-8 */
1048                 snprintf(buf, sizeof(buf),
1049                         "T10 VPD UTF-8 Device Identifier: %s\n",
1050                         &vpd->device_identifier[0]);
1051                 break;
1052         default:
1053                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1054                         " 0x%02x", vpd->device_identifier_code_set);
1055                 ret = -EINVAL;
1056                 break;
1057         }
1058
1059         if (p_buf)
1060                 strncpy(p_buf, buf, p_buf_len);
1061         else
1062                 pr_debug("%s", buf);
1063
1064         return ret;
1065 }
1066
1067 int
1068 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1069 {
1070         static const char hex_str[] = "0123456789abcdef";
1071         int j = 0, i = 4; /* offset to start of the identifier */
1072
1073         /*
1074          * The VPD Code Set (encoding)
1075          *
1076          * from spc3r23.pdf Section 7.6.3.1 Table 296
1077          */
1078         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1079         switch (vpd->device_identifier_code_set) {
1080         case 0x01: /* Binary */
1081                 vpd->device_identifier[j++] =
1082                                 hex_str[vpd->device_identifier_type];
1083                 while (i < (4 + page_83[3])) {
1084                         vpd->device_identifier[j++] =
1085                                 hex_str[(page_83[i] & 0xf0) >> 4];
1086                         vpd->device_identifier[j++] =
1087                                 hex_str[page_83[i] & 0x0f];
1088                         i++;
1089                 }
1090                 break;
1091         case 0x02: /* ASCII */
1092         case 0x03: /* UTF-8 */
1093                 while (i < (4 + page_83[3]))
1094                         vpd->device_identifier[j++] = page_83[i++];
1095                 break;
1096         default:
1097                 break;
1098         }
1099
1100         return transport_dump_vpd_ident(vpd, NULL, 0);
1101 }
1102 EXPORT_SYMBOL(transport_set_vpd_ident);
1103
1104 static sense_reason_t
1105 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1106                                unsigned int size)
1107 {
1108         u32 mtl;
1109
1110         if (!cmd->se_tfo->max_data_sg_nents)
1111                 return TCM_NO_SENSE;
1112         /*
1113          * Check if fabric enforced maximum SGL entries per I/O descriptor
1114          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1115          * residual_count and reduce original cmd->data_length to maximum
1116          * length based on single PAGE_SIZE entry scatter-lists.
1117          */
1118         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1119         if (cmd->data_length > mtl) {
1120                 /*
1121                  * If an existing CDB overflow is present, calculate new residual
1122                  * based on CDB size minus fabric maximum transfer length.
1123                  *
1124                  * If an existing CDB underflow is present, calculate new residual
1125                  * based on original cmd->data_length minus fabric maximum transfer
1126                  * length.
1127                  *
1128                  * Otherwise, set the underflow residual based on cmd->data_length
1129                  * minus fabric maximum transfer length.
1130                  */
1131                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1132                         cmd->residual_count = (size - mtl);
1133                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1134                         u32 orig_dl = size + cmd->residual_count;
1135                         cmd->residual_count = (orig_dl - mtl);
1136                 } else {
1137                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1138                         cmd->residual_count = (cmd->data_length - mtl);
1139                 }
1140                 cmd->data_length = mtl;
1141                 /*
1142                  * Reset sbc_check_prot() calculated protection payload
1143                  * length based upon the new smaller MTL.
1144                  */
1145                 if (cmd->prot_length) {
1146                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1147                         cmd->prot_length = dev->prot_length * sectors;
1148                 }
1149         }
1150         return TCM_NO_SENSE;
1151 }
1152
1153 sense_reason_t
1154 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1155 {
1156         struct se_device *dev = cmd->se_dev;
1157
1158         if (cmd->unknown_data_length) {
1159                 cmd->data_length = size;
1160         } else if (size != cmd->data_length) {
1161                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1162                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1163                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1164                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1165
1166                 if (cmd->data_direction == DMA_TO_DEVICE &&
1167                     cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1168                         pr_err("Rejecting underflow/overflow WRITE data\n");
1169                         return TCM_INVALID_CDB_FIELD;
1170                 }
1171                 /*
1172                  * Reject READ_* or WRITE_* with overflow/underflow for
1173                  * type SCF_SCSI_DATA_CDB.
1174                  */
1175                 if (dev->dev_attrib.block_size != 512)  {
1176                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1177                                 " CDB on non 512-byte sector setup subsystem"
1178                                 " plugin: %s\n", dev->transport->name);
1179                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1180                         return TCM_INVALID_CDB_FIELD;
1181                 }
1182                 /*
1183                  * For the overflow case keep the existing fabric provided
1184                  * ->data_length.  Otherwise for the underflow case, reset
1185                  * ->data_length to the smaller SCSI expected data transfer
1186                  * length.
1187                  */
1188                 if (size > cmd->data_length) {
1189                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1190                         cmd->residual_count = (size - cmd->data_length);
1191                 } else {
1192                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1193                         cmd->residual_count = (cmd->data_length - size);
1194                         cmd->data_length = size;
1195                 }
1196         }
1197
1198         return target_check_max_data_sg_nents(cmd, dev, size);
1199
1200 }
1201
1202 /*
1203  * Used by fabric modules containing a local struct se_cmd within their
1204  * fabric dependent per I/O descriptor.
1205  *
1206  * Preserves the value of @cmd->tag.
1207  */
1208 void transport_init_se_cmd(
1209         struct se_cmd *cmd,
1210         const struct target_core_fabric_ops *tfo,
1211         struct se_session *se_sess,
1212         u32 data_length,
1213         int data_direction,
1214         int task_attr,
1215         unsigned char *sense_buffer)
1216 {
1217         INIT_LIST_HEAD(&cmd->se_delayed_node);
1218         INIT_LIST_HEAD(&cmd->se_qf_node);
1219         INIT_LIST_HEAD(&cmd->se_cmd_list);
1220         INIT_LIST_HEAD(&cmd->state_list);
1221         init_completion(&cmd->t_transport_stop_comp);
1222         init_completion(&cmd->cmd_wait_comp);
1223         spin_lock_init(&cmd->t_state_lock);
1224         kref_init(&cmd->cmd_kref);
1225
1226         cmd->se_tfo = tfo;
1227         cmd->se_sess = se_sess;
1228         cmd->data_length = data_length;
1229         cmd->data_direction = data_direction;
1230         cmd->sam_task_attr = task_attr;
1231         cmd->sense_buffer = sense_buffer;
1232
1233         cmd->state_active = false;
1234 }
1235 EXPORT_SYMBOL(transport_init_se_cmd);
1236
1237 static sense_reason_t
1238 transport_check_alloc_task_attr(struct se_cmd *cmd)
1239 {
1240         struct se_device *dev = cmd->se_dev;
1241
1242         /*
1243          * Check if SAM Task Attribute emulation is enabled for this
1244          * struct se_device storage object
1245          */
1246         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1247                 return 0;
1248
1249         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1250                 pr_debug("SAM Task Attribute ACA"
1251                         " emulation is not supported\n");
1252                 return TCM_INVALID_CDB_FIELD;
1253         }
1254
1255         return 0;
1256 }
1257
1258 sense_reason_t
1259 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1260 {
1261         struct se_device *dev = cmd->se_dev;
1262         sense_reason_t ret;
1263
1264         /*
1265          * Ensure that the received CDB is less than the max (252 + 8) bytes
1266          * for VARIABLE_LENGTH_CMD
1267          */
1268         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1269                 pr_err("Received SCSI CDB with command_size: %d that"
1270                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1271                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1272                 return TCM_INVALID_CDB_FIELD;
1273         }
1274         /*
1275          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1276          * allocate the additional extended CDB buffer now..  Otherwise
1277          * setup the pointer from __t_task_cdb to t_task_cdb.
1278          */
1279         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1280                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1281                                                 GFP_KERNEL);
1282                 if (!cmd->t_task_cdb) {
1283                         pr_err("Unable to allocate cmd->t_task_cdb"
1284                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1285                                 scsi_command_size(cdb),
1286                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1287                         return TCM_OUT_OF_RESOURCES;
1288                 }
1289         } else
1290                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1291         /*
1292          * Copy the original CDB into cmd->
1293          */
1294         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1295
1296         trace_target_sequencer_start(cmd);
1297
1298         ret = dev->transport->parse_cdb(cmd);
1299         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1300                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1301                                     cmd->se_tfo->get_fabric_name(),
1302                                     cmd->se_sess->se_node_acl->initiatorname,
1303                                     cmd->t_task_cdb[0]);
1304         if (ret)
1305                 return ret;
1306
1307         ret = transport_check_alloc_task_attr(cmd);
1308         if (ret)
1309                 return ret;
1310
1311         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1312         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1313         return 0;
1314 }
1315 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1316
1317 /*
1318  * Used by fabric module frontends to queue tasks directly.
1319  * May only be used from process context.
1320  */
1321 int transport_handle_cdb_direct(
1322         struct se_cmd *cmd)
1323 {
1324         sense_reason_t ret;
1325
1326         if (!cmd->se_lun) {
1327                 dump_stack();
1328                 pr_err("cmd->se_lun is NULL\n");
1329                 return -EINVAL;
1330         }
1331         if (in_interrupt()) {
1332                 dump_stack();
1333                 pr_err("transport_generic_handle_cdb cannot be called"
1334                                 " from interrupt context\n");
1335                 return -EINVAL;
1336         }
1337         /*
1338          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1339          * outstanding descriptors are handled correctly during shutdown via
1340          * transport_wait_for_tasks()
1341          *
1342          * Also, we don't take cmd->t_state_lock here as we only expect
1343          * this to be called for initial descriptor submission.
1344          */
1345         cmd->t_state = TRANSPORT_NEW_CMD;
1346         cmd->transport_state |= CMD_T_ACTIVE;
1347
1348         /*
1349          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1350          * so follow TRANSPORT_NEW_CMD processing thread context usage
1351          * and call transport_generic_request_failure() if necessary..
1352          */
1353         ret = transport_generic_new_cmd(cmd);
1354         if (ret)
1355                 transport_generic_request_failure(cmd, ret);
1356         return 0;
1357 }
1358 EXPORT_SYMBOL(transport_handle_cdb_direct);
1359
1360 sense_reason_t
1361 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1362                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1363 {
1364         if (!sgl || !sgl_count)
1365                 return 0;
1366
1367         /*
1368          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1369          * scatterlists already have been set to follow what the fabric
1370          * passes for the original expected data transfer length.
1371          */
1372         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1373                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1374                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1375                 return TCM_INVALID_CDB_FIELD;
1376         }
1377
1378         cmd->t_data_sg = sgl;
1379         cmd->t_data_nents = sgl_count;
1380         cmd->t_bidi_data_sg = sgl_bidi;
1381         cmd->t_bidi_data_nents = sgl_bidi_count;
1382
1383         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1384         return 0;
1385 }
1386
1387 /*
1388  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1389  *                       se_cmd + use pre-allocated SGL memory.
1390  *
1391  * @se_cmd: command descriptor to submit
1392  * @se_sess: associated se_sess for endpoint
1393  * @cdb: pointer to SCSI CDB
1394  * @sense: pointer to SCSI sense buffer
1395  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1396  * @data_length: fabric expected data transfer length
1397  * @task_addr: SAM task attribute
1398  * @data_dir: DMA data direction
1399  * @flags: flags for command submission from target_sc_flags_tables
1400  * @sgl: struct scatterlist memory for unidirectional mapping
1401  * @sgl_count: scatterlist count for unidirectional mapping
1402  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1403  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1404  * @sgl_prot: struct scatterlist memory protection information
1405  * @sgl_prot_count: scatterlist count for protection information
1406  *
1407  * Task tags are supported if the caller has set @se_cmd->tag.
1408  *
1409  * Returns non zero to signal active I/O shutdown failure.  All other
1410  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1411  * but still return zero here.
1412  *
1413  * This may only be called from process context, and also currently
1414  * assumes internal allocation of fabric payload buffer by target-core.
1415  */
1416 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1417                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1418                 u32 data_length, int task_attr, int data_dir, int flags,
1419                 struct scatterlist *sgl, u32 sgl_count,
1420                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1421                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1422 {
1423         struct se_portal_group *se_tpg;
1424         sense_reason_t rc;
1425         int ret;
1426
1427         se_tpg = se_sess->se_tpg;
1428         BUG_ON(!se_tpg);
1429         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1430         BUG_ON(in_interrupt());
1431         /*
1432          * Initialize se_cmd for target operation.  From this point
1433          * exceptions are handled by sending exception status via
1434          * target_core_fabric_ops->queue_status() callback
1435          */
1436         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1437                                 data_length, data_dir, task_attr, sense);
1438
1439         if (flags & TARGET_SCF_USE_CPUID)
1440                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1441         else
1442                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1443
1444         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1445                 se_cmd->unknown_data_length = 1;
1446         /*
1447          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1448          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1449          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1450          * kref_put() to happen during fabric packet acknowledgement.
1451          */
1452         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1453         if (ret)
1454                 return ret;
1455         /*
1456          * Signal bidirectional data payloads to target-core
1457          */
1458         if (flags & TARGET_SCF_BIDI_OP)
1459                 se_cmd->se_cmd_flags |= SCF_BIDI;
1460         /*
1461          * Locate se_lun pointer and attach it to struct se_cmd
1462          */
1463         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1464         if (rc) {
1465                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1466                 target_put_sess_cmd(se_cmd);
1467                 return 0;
1468         }
1469
1470         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1471         if (rc != 0) {
1472                 transport_generic_request_failure(se_cmd, rc);
1473                 return 0;
1474         }
1475
1476         /*
1477          * Save pointers for SGLs containing protection information,
1478          * if present.
1479          */
1480         if (sgl_prot_count) {
1481                 se_cmd->t_prot_sg = sgl_prot;
1482                 se_cmd->t_prot_nents = sgl_prot_count;
1483                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1484         }
1485
1486         /*
1487          * When a non zero sgl_count has been passed perform SGL passthrough
1488          * mapping for pre-allocated fabric memory instead of having target
1489          * core perform an internal SGL allocation..
1490          */
1491         if (sgl_count != 0) {
1492                 BUG_ON(!sgl);
1493
1494                 /*
1495                  * A work-around for tcm_loop as some userspace code via
1496                  * scsi-generic do not memset their associated read buffers,
1497                  * so go ahead and do that here for type non-data CDBs.  Also
1498                  * note that this is currently guaranteed to be a single SGL
1499                  * for this case by target core in target_setup_cmd_from_cdb()
1500                  * -> transport_generic_cmd_sequencer().
1501                  */
1502                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1503                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1504                         unsigned char *buf = NULL;
1505
1506                         if (sgl)
1507                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1508
1509                         if (buf) {
1510                                 memset(buf, 0, sgl->length);
1511                                 kunmap(sg_page(sgl));
1512                         }
1513                 }
1514
1515                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1516                                 sgl_bidi, sgl_bidi_count);
1517                 if (rc != 0) {
1518                         transport_generic_request_failure(se_cmd, rc);
1519                         return 0;
1520                 }
1521         }
1522
1523         /*
1524          * Check if we need to delay processing because of ALUA
1525          * Active/NonOptimized primary access state..
1526          */
1527         core_alua_check_nonop_delay(se_cmd);
1528
1529         transport_handle_cdb_direct(se_cmd);
1530         return 0;
1531 }
1532 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1533
1534 /*
1535  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1536  *
1537  * @se_cmd: command descriptor to submit
1538  * @se_sess: associated se_sess for endpoint
1539  * @cdb: pointer to SCSI CDB
1540  * @sense: pointer to SCSI sense buffer
1541  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1542  * @data_length: fabric expected data transfer length
1543  * @task_addr: SAM task attribute
1544  * @data_dir: DMA data direction
1545  * @flags: flags for command submission from target_sc_flags_tables
1546  *
1547  * Task tags are supported if the caller has set @se_cmd->tag.
1548  *
1549  * Returns non zero to signal active I/O shutdown failure.  All other
1550  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1551  * but still return zero here.
1552  *
1553  * This may only be called from process context, and also currently
1554  * assumes internal allocation of fabric payload buffer by target-core.
1555  *
1556  * It also assumes interal target core SGL memory allocation.
1557  */
1558 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1559                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1560                 u32 data_length, int task_attr, int data_dir, int flags)
1561 {
1562         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1563                         unpacked_lun, data_length, task_attr, data_dir,
1564                         flags, NULL, 0, NULL, 0, NULL, 0);
1565 }
1566 EXPORT_SYMBOL(target_submit_cmd);
1567
1568 static void target_complete_tmr_failure(struct work_struct *work)
1569 {
1570         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1571
1572         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1573         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1574
1575         transport_cmd_check_stop_to_fabric(se_cmd);
1576 }
1577
1578 /**
1579  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1580  *                     for TMR CDBs
1581  *
1582  * @se_cmd: command descriptor to submit
1583  * @se_sess: associated se_sess for endpoint
1584  * @sense: pointer to SCSI sense buffer
1585  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1586  * @fabric_context: fabric context for TMR req
1587  * @tm_type: Type of TM request
1588  * @gfp: gfp type for caller
1589  * @tag: referenced task tag for TMR_ABORT_TASK
1590  * @flags: submit cmd flags
1591  *
1592  * Callable from all contexts.
1593  **/
1594
1595 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1596                 unsigned char *sense, u64 unpacked_lun,
1597                 void *fabric_tmr_ptr, unsigned char tm_type,
1598                 gfp_t gfp, u64 tag, int flags)
1599 {
1600         struct se_portal_group *se_tpg;
1601         int ret;
1602
1603         se_tpg = se_sess->se_tpg;
1604         BUG_ON(!se_tpg);
1605
1606         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1607                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1608         /*
1609          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1610          * allocation failure.
1611          */
1612         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1613         if (ret < 0)
1614                 return -ENOMEM;
1615
1616         if (tm_type == TMR_ABORT_TASK)
1617                 se_cmd->se_tmr_req->ref_task_tag = tag;
1618
1619         /* See target_submit_cmd for commentary */
1620         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1621         if (ret) {
1622                 core_tmr_release_req(se_cmd->se_tmr_req);
1623                 return ret;
1624         }
1625
1626         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1627         if (ret) {
1628                 /*
1629                  * For callback during failure handling, push this work off
1630                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1631                  */
1632                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1633                 schedule_work(&se_cmd->work);
1634                 return 0;
1635         }
1636         transport_generic_handle_tmr(se_cmd);
1637         return 0;
1638 }
1639 EXPORT_SYMBOL(target_submit_tmr);
1640
1641 /*
1642  * Handle SAM-esque emulation for generic transport request failures.
1643  */
1644 void transport_generic_request_failure(struct se_cmd *cmd,
1645                 sense_reason_t sense_reason)
1646 {
1647         int ret = 0, post_ret = 0;
1648
1649         if (transport_check_aborted_status(cmd, 1))
1650                 return;
1651
1652         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1653                 " CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1654         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1655                 cmd->se_tfo->get_cmd_state(cmd),
1656                 cmd->t_state, sense_reason);
1657         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1658                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1659                 (cmd->transport_state & CMD_T_STOP) != 0,
1660                 (cmd->transport_state & CMD_T_SENT) != 0);
1661
1662         /*
1663          * For SAM Task Attribute emulation for failed struct se_cmd
1664          */
1665         transport_complete_task_attr(cmd);
1666         /*
1667          * Handle special case for COMPARE_AND_WRITE failure, where the
1668          * callback is expected to drop the per device ->caw_sem.
1669          */
1670         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1671              cmd->transport_complete_callback)
1672                 cmd->transport_complete_callback(cmd, false, &post_ret);
1673
1674         switch (sense_reason) {
1675         case TCM_NON_EXISTENT_LUN:
1676         case TCM_UNSUPPORTED_SCSI_OPCODE:
1677         case TCM_INVALID_CDB_FIELD:
1678         case TCM_INVALID_PARAMETER_LIST:
1679         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1680         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1681         case TCM_UNKNOWN_MODE_PAGE:
1682         case TCM_WRITE_PROTECTED:
1683         case TCM_ADDRESS_OUT_OF_RANGE:
1684         case TCM_CHECK_CONDITION_ABORT_CMD:
1685         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1686         case TCM_CHECK_CONDITION_NOT_READY:
1687         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1688         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1689         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1690         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1691         case TCM_TOO_MANY_TARGET_DESCS:
1692         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1693         case TCM_TOO_MANY_SEGMENT_DESCS:
1694         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1695                 break;
1696         case TCM_OUT_OF_RESOURCES:
1697                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1698                 break;
1699         case TCM_RESERVATION_CONFLICT:
1700                 /*
1701                  * No SENSE Data payload for this case, set SCSI Status
1702                  * and queue the response to $FABRIC_MOD.
1703                  *
1704                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1705                  */
1706                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1707                 /*
1708                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1709                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1710                  * CONFLICT STATUS.
1711                  *
1712                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1713                  */
1714                 if (cmd->se_sess &&
1715                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1716                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1717                                                cmd->orig_fe_lun, 0x2C,
1718                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1719                 }
1720                 trace_target_cmd_complete(cmd);
1721                 ret = cmd->se_tfo->queue_status(cmd);
1722                 if (ret == -EAGAIN || ret == -ENOMEM)
1723                         goto queue_full;
1724                 goto check_stop;
1725         default:
1726                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1727                         cmd->t_task_cdb[0], sense_reason);
1728                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1729                 break;
1730         }
1731
1732         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1733         if (ret == -EAGAIN || ret == -ENOMEM)
1734                 goto queue_full;
1735
1736 check_stop:
1737         transport_lun_remove_cmd(cmd);
1738         transport_cmd_check_stop_to_fabric(cmd);
1739         return;
1740
1741 queue_full:
1742         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1743         transport_handle_queue_full(cmd, cmd->se_dev);
1744 }
1745 EXPORT_SYMBOL(transport_generic_request_failure);
1746
1747 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1748 {
1749         sense_reason_t ret;
1750
1751         if (!cmd->execute_cmd) {
1752                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1753                 goto err;
1754         }
1755         if (do_checks) {
1756                 /*
1757                  * Check for an existing UNIT ATTENTION condition after
1758                  * target_handle_task_attr() has done SAM task attr
1759                  * checking, and possibly have already defered execution
1760                  * out to target_restart_delayed_cmds() context.
1761                  */
1762                 ret = target_scsi3_ua_check(cmd);
1763                 if (ret)
1764                         goto err;
1765
1766                 ret = target_alua_state_check(cmd);
1767                 if (ret)
1768                         goto err;
1769
1770                 ret = target_check_reservation(cmd);
1771                 if (ret) {
1772                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1773                         goto err;
1774                 }
1775         }
1776
1777         ret = cmd->execute_cmd(cmd);
1778         if (!ret)
1779                 return;
1780 err:
1781         spin_lock_irq(&cmd->t_state_lock);
1782         cmd->transport_state &= ~CMD_T_SENT;
1783         spin_unlock_irq(&cmd->t_state_lock);
1784
1785         transport_generic_request_failure(cmd, ret);
1786 }
1787
1788 static int target_write_prot_action(struct se_cmd *cmd)
1789 {
1790         u32 sectors;
1791         /*
1792          * Perform WRITE_INSERT of PI using software emulation when backend
1793          * device has PI enabled, if the transport has not already generated
1794          * PI using hardware WRITE_INSERT offload.
1795          */
1796         switch (cmd->prot_op) {
1797         case TARGET_PROT_DOUT_INSERT:
1798                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1799                         sbc_dif_generate(cmd);
1800                 break;
1801         case TARGET_PROT_DOUT_STRIP:
1802                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1803                         break;
1804
1805                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1806                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1807                                              sectors, 0, cmd->t_prot_sg, 0);
1808                 if (unlikely(cmd->pi_err)) {
1809                         spin_lock_irq(&cmd->t_state_lock);
1810                         cmd->transport_state &= ~CMD_T_SENT;
1811                         spin_unlock_irq(&cmd->t_state_lock);
1812                         transport_generic_request_failure(cmd, cmd->pi_err);
1813                         return -1;
1814                 }
1815                 break;
1816         default:
1817                 break;
1818         }
1819
1820         return 0;
1821 }
1822
1823 static bool target_handle_task_attr(struct se_cmd *cmd)
1824 {
1825         struct se_device *dev = cmd->se_dev;
1826
1827         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1828                 return false;
1829
1830         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1831
1832         /*
1833          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1834          * to allow the passed struct se_cmd list of tasks to the front of the list.
1835          */
1836         switch (cmd->sam_task_attr) {
1837         case TCM_HEAD_TAG:
1838                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1839                          cmd->t_task_cdb[0]);
1840                 return false;
1841         case TCM_ORDERED_TAG:
1842                 atomic_inc_mb(&dev->dev_ordered_sync);
1843
1844                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1845                          cmd->t_task_cdb[0]);
1846
1847                 /*
1848                  * Execute an ORDERED command if no other older commands
1849                  * exist that need to be completed first.
1850                  */
1851                 if (!atomic_read(&dev->simple_cmds))
1852                         return false;
1853                 break;
1854         default:
1855                 /*
1856                  * For SIMPLE and UNTAGGED Task Attribute commands
1857                  */
1858                 atomic_inc_mb(&dev->simple_cmds);
1859                 break;
1860         }
1861
1862         if (atomic_read(&dev->dev_ordered_sync) == 0)
1863                 return false;
1864
1865         spin_lock(&dev->delayed_cmd_lock);
1866         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1867         spin_unlock(&dev->delayed_cmd_lock);
1868
1869         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1870                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1871         return true;
1872 }
1873
1874 static int __transport_check_aborted_status(struct se_cmd *, int);
1875
1876 void target_execute_cmd(struct se_cmd *cmd)
1877 {
1878         /*
1879          * Determine if frontend context caller is requesting the stopping of
1880          * this command for frontend exceptions.
1881          *
1882          * If the received CDB has aleady been aborted stop processing it here.
1883          */
1884         spin_lock_irq(&cmd->t_state_lock);
1885         if (__transport_check_aborted_status(cmd, 1)) {
1886                 spin_unlock_irq(&cmd->t_state_lock);
1887                 return;
1888         }
1889         if (cmd->transport_state & CMD_T_STOP) {
1890                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1891                         __func__, __LINE__, cmd->tag);
1892
1893                 spin_unlock_irq(&cmd->t_state_lock);
1894                 complete_all(&cmd->t_transport_stop_comp);
1895                 return;
1896         }
1897
1898         cmd->t_state = TRANSPORT_PROCESSING;
1899         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
1900         spin_unlock_irq(&cmd->t_state_lock);
1901
1902         if (target_write_prot_action(cmd))
1903                 return;
1904
1905         if (target_handle_task_attr(cmd)) {
1906                 spin_lock_irq(&cmd->t_state_lock);
1907                 cmd->transport_state &= ~CMD_T_SENT;
1908                 spin_unlock_irq(&cmd->t_state_lock);
1909                 return;
1910         }
1911
1912         __target_execute_cmd(cmd, true);
1913 }
1914 EXPORT_SYMBOL(target_execute_cmd);
1915
1916 /*
1917  * Process all commands up to the last received ORDERED task attribute which
1918  * requires another blocking boundary
1919  */
1920 static void target_restart_delayed_cmds(struct se_device *dev)
1921 {
1922         for (;;) {
1923                 struct se_cmd *cmd;
1924
1925                 spin_lock(&dev->delayed_cmd_lock);
1926                 if (list_empty(&dev->delayed_cmd_list)) {
1927                         spin_unlock(&dev->delayed_cmd_lock);
1928                         break;
1929                 }
1930
1931                 cmd = list_entry(dev->delayed_cmd_list.next,
1932                                  struct se_cmd, se_delayed_node);
1933                 list_del(&cmd->se_delayed_node);
1934                 spin_unlock(&dev->delayed_cmd_lock);
1935
1936                 __target_execute_cmd(cmd, true);
1937
1938                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1939                         break;
1940         }
1941 }
1942
1943 /*
1944  * Called from I/O completion to determine which dormant/delayed
1945  * and ordered cmds need to have their tasks added to the execution queue.
1946  */
1947 static void transport_complete_task_attr(struct se_cmd *cmd)
1948 {
1949         struct se_device *dev = cmd->se_dev;
1950
1951         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1952                 return;
1953
1954         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
1955                 goto restart;
1956
1957         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1958                 atomic_dec_mb(&dev->simple_cmds);
1959                 dev->dev_cur_ordered_id++;
1960         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1961                 dev->dev_cur_ordered_id++;
1962                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1963                          dev->dev_cur_ordered_id);
1964         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1965                 atomic_dec_mb(&dev->dev_ordered_sync);
1966
1967                 dev->dev_cur_ordered_id++;
1968                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1969                          dev->dev_cur_ordered_id);
1970         }
1971 restart:
1972         target_restart_delayed_cmds(dev);
1973 }
1974
1975 static void transport_complete_qf(struct se_cmd *cmd)
1976 {
1977         int ret = 0;
1978
1979         transport_complete_task_attr(cmd);
1980
1981         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1982                 trace_target_cmd_complete(cmd);
1983                 ret = cmd->se_tfo->queue_status(cmd);
1984                 goto out;
1985         }
1986
1987         switch (cmd->data_direction) {
1988         case DMA_FROM_DEVICE:
1989                 if (cmd->scsi_status)
1990                         goto queue_status;
1991
1992                 trace_target_cmd_complete(cmd);
1993                 ret = cmd->se_tfo->queue_data_in(cmd);
1994                 break;
1995         case DMA_TO_DEVICE:
1996                 if (cmd->se_cmd_flags & SCF_BIDI) {
1997                         ret = cmd->se_tfo->queue_data_in(cmd);
1998                         break;
1999                 }
2000                 /* Fall through for DMA_TO_DEVICE */
2001         case DMA_NONE:
2002 queue_status:
2003                 trace_target_cmd_complete(cmd);
2004                 ret = cmd->se_tfo->queue_status(cmd);
2005                 break;
2006         default:
2007                 break;
2008         }
2009
2010 out:
2011         if (ret < 0) {
2012                 transport_handle_queue_full(cmd, cmd->se_dev);
2013                 return;
2014         }
2015         transport_lun_remove_cmd(cmd);
2016         transport_cmd_check_stop_to_fabric(cmd);
2017 }
2018
2019 static void transport_handle_queue_full(
2020         struct se_cmd *cmd,
2021         struct se_device *dev)
2022 {
2023         spin_lock_irq(&dev->qf_cmd_lock);
2024         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2025         atomic_inc_mb(&dev->dev_qf_count);
2026         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2027
2028         schedule_work(&cmd->se_dev->qf_work_queue);
2029 }
2030
2031 static bool target_read_prot_action(struct se_cmd *cmd)
2032 {
2033         switch (cmd->prot_op) {
2034         case TARGET_PROT_DIN_STRIP:
2035                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2036                         u32 sectors = cmd->data_length >>
2037                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2038
2039                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2040                                                      sectors, 0, cmd->t_prot_sg,
2041                                                      0);
2042                         if (cmd->pi_err)
2043                                 return true;
2044                 }
2045                 break;
2046         case TARGET_PROT_DIN_INSERT:
2047                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2048                         break;
2049
2050                 sbc_dif_generate(cmd);
2051                 break;
2052         default:
2053                 break;
2054         }
2055
2056         return false;
2057 }
2058
2059 static void target_complete_ok_work(struct work_struct *work)
2060 {
2061         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2062         int ret;
2063
2064         /*
2065          * Check if we need to move delayed/dormant tasks from cmds on the
2066          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2067          * Attribute.
2068          */
2069         transport_complete_task_attr(cmd);
2070
2071         /*
2072          * Check to schedule QUEUE_FULL work, or execute an existing
2073          * cmd->transport_qf_callback()
2074          */
2075         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2076                 schedule_work(&cmd->se_dev->qf_work_queue);
2077
2078         /*
2079          * Check if we need to send a sense buffer from
2080          * the struct se_cmd in question.
2081          */
2082         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2083                 WARN_ON(!cmd->scsi_status);
2084                 ret = transport_send_check_condition_and_sense(
2085                                         cmd, 0, 1);
2086                 if (ret == -EAGAIN || ret == -ENOMEM)
2087                         goto queue_full;
2088
2089                 transport_lun_remove_cmd(cmd);
2090                 transport_cmd_check_stop_to_fabric(cmd);
2091                 return;
2092         }
2093         /*
2094          * Check for a callback, used by amongst other things
2095          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2096          */
2097         if (cmd->transport_complete_callback) {
2098                 sense_reason_t rc;
2099                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2100                 bool zero_dl = !(cmd->data_length);
2101                 int post_ret = 0;
2102
2103                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2104                 if (!rc && !post_ret) {
2105                         if (caw && zero_dl)
2106                                 goto queue_rsp;
2107
2108                         return;
2109                 } else if (rc) {
2110                         ret = transport_send_check_condition_and_sense(cmd,
2111                                                 rc, 0);
2112                         if (ret == -EAGAIN || ret == -ENOMEM)
2113                                 goto queue_full;
2114
2115                         transport_lun_remove_cmd(cmd);
2116                         transport_cmd_check_stop_to_fabric(cmd);
2117                         return;
2118                 }
2119         }
2120
2121 queue_rsp:
2122         switch (cmd->data_direction) {
2123         case DMA_FROM_DEVICE:
2124                 if (cmd->scsi_status)
2125                         goto queue_status;
2126
2127                 atomic_long_add(cmd->data_length,
2128                                 &cmd->se_lun->lun_stats.tx_data_octets);
2129                 /*
2130                  * Perform READ_STRIP of PI using software emulation when
2131                  * backend had PI enabled, if the transport will not be
2132                  * performing hardware READ_STRIP offload.
2133                  */
2134                 if (target_read_prot_action(cmd)) {
2135                         ret = transport_send_check_condition_and_sense(cmd,
2136                                                 cmd->pi_err, 0);
2137                         if (ret == -EAGAIN || ret == -ENOMEM)
2138                                 goto queue_full;
2139
2140                         transport_lun_remove_cmd(cmd);
2141                         transport_cmd_check_stop_to_fabric(cmd);
2142                         return;
2143                 }
2144
2145                 trace_target_cmd_complete(cmd);
2146                 ret = cmd->se_tfo->queue_data_in(cmd);
2147                 if (ret == -EAGAIN || ret == -ENOMEM)
2148                         goto queue_full;
2149                 break;
2150         case DMA_TO_DEVICE:
2151                 atomic_long_add(cmd->data_length,
2152                                 &cmd->se_lun->lun_stats.rx_data_octets);
2153                 /*
2154                  * Check if we need to send READ payload for BIDI-COMMAND
2155                  */
2156                 if (cmd->se_cmd_flags & SCF_BIDI) {
2157                         atomic_long_add(cmd->data_length,
2158                                         &cmd->se_lun->lun_stats.tx_data_octets);
2159                         ret = cmd->se_tfo->queue_data_in(cmd);
2160                         if (ret == -EAGAIN || ret == -ENOMEM)
2161                                 goto queue_full;
2162                         break;
2163                 }
2164                 /* Fall through for DMA_TO_DEVICE */
2165         case DMA_NONE:
2166 queue_status:
2167                 trace_target_cmd_complete(cmd);
2168                 ret = cmd->se_tfo->queue_status(cmd);
2169                 if (ret == -EAGAIN || ret == -ENOMEM)
2170                         goto queue_full;
2171                 break;
2172         default:
2173                 break;
2174         }
2175
2176         transport_lun_remove_cmd(cmd);
2177         transport_cmd_check_stop_to_fabric(cmd);
2178         return;
2179
2180 queue_full:
2181         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2182                 " data_direction: %d\n", cmd, cmd->data_direction);
2183         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2184         transport_handle_queue_full(cmd, cmd->se_dev);
2185 }
2186
2187 void target_free_sgl(struct scatterlist *sgl, int nents)
2188 {
2189         struct scatterlist *sg;
2190         int count;
2191
2192         for_each_sg(sgl, sg, nents, count)
2193                 __free_page(sg_page(sg));
2194
2195         kfree(sgl);
2196 }
2197 EXPORT_SYMBOL(target_free_sgl);
2198
2199 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2200 {
2201         /*
2202          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2203          * emulation, and free + reset pointers if necessary..
2204          */
2205         if (!cmd->t_data_sg_orig)
2206                 return;
2207
2208         kfree(cmd->t_data_sg);
2209         cmd->t_data_sg = cmd->t_data_sg_orig;
2210         cmd->t_data_sg_orig = NULL;
2211         cmd->t_data_nents = cmd->t_data_nents_orig;
2212         cmd->t_data_nents_orig = 0;
2213 }
2214
2215 static inline void transport_free_pages(struct se_cmd *cmd)
2216 {
2217         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2218                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2219                 cmd->t_prot_sg = NULL;
2220                 cmd->t_prot_nents = 0;
2221         }
2222
2223         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2224                 /*
2225                  * Release special case READ buffer payload required for
2226                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2227                  */
2228                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2229                         target_free_sgl(cmd->t_bidi_data_sg,
2230                                            cmd->t_bidi_data_nents);
2231                         cmd->t_bidi_data_sg = NULL;
2232                         cmd->t_bidi_data_nents = 0;
2233                 }
2234                 transport_reset_sgl_orig(cmd);
2235                 return;
2236         }
2237         transport_reset_sgl_orig(cmd);
2238
2239         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2240         cmd->t_data_sg = NULL;
2241         cmd->t_data_nents = 0;
2242
2243         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2244         cmd->t_bidi_data_sg = NULL;
2245         cmd->t_bidi_data_nents = 0;
2246 }
2247
2248 /**
2249  * transport_put_cmd - release a reference to a command
2250  * @cmd:       command to release
2251  *
2252  * This routine releases our reference to the command and frees it if possible.
2253  */
2254 static int transport_put_cmd(struct se_cmd *cmd)
2255 {
2256         BUG_ON(!cmd->se_tfo);
2257         /*
2258          * If this cmd has been setup with target_get_sess_cmd(), drop
2259          * the kref and call ->release_cmd() in kref callback.
2260          */
2261         return target_put_sess_cmd(cmd);
2262 }
2263
2264 void *transport_kmap_data_sg(struct se_cmd *cmd)
2265 {
2266         struct scatterlist *sg = cmd->t_data_sg;
2267         struct page **pages;
2268         int i;
2269
2270         /*
2271          * We need to take into account a possible offset here for fabrics like
2272          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2273          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2274          */
2275         if (!cmd->t_data_nents)
2276                 return NULL;
2277
2278         BUG_ON(!sg);
2279         if (cmd->t_data_nents == 1)
2280                 return kmap(sg_page(sg)) + sg->offset;
2281
2282         /* >1 page. use vmap */
2283         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2284         if (!pages)
2285                 return NULL;
2286
2287         /* convert sg[] to pages[] */
2288         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2289                 pages[i] = sg_page(sg);
2290         }
2291
2292         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2293         kfree(pages);
2294         if (!cmd->t_data_vmap)
2295                 return NULL;
2296
2297         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2298 }
2299 EXPORT_SYMBOL(transport_kmap_data_sg);
2300
2301 void transport_kunmap_data_sg(struct se_cmd *cmd)
2302 {
2303         if (!cmd->t_data_nents) {
2304                 return;
2305         } else if (cmd->t_data_nents == 1) {
2306                 kunmap(sg_page(cmd->t_data_sg));
2307                 return;
2308         }
2309
2310         vunmap(cmd->t_data_vmap);
2311         cmd->t_data_vmap = NULL;
2312 }
2313 EXPORT_SYMBOL(transport_kunmap_data_sg);
2314
2315 int
2316 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2317                  bool zero_page, bool chainable)
2318 {
2319         struct scatterlist *sg;
2320         struct page *page;
2321         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2322         unsigned int nalloc, nent;
2323         int i = 0;
2324
2325         nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2326         if (chainable)
2327                 nalloc++;
2328         sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2329         if (!sg)
2330                 return -ENOMEM;
2331
2332         sg_init_table(sg, nalloc);
2333
2334         while (length) {
2335                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2336                 page = alloc_page(GFP_KERNEL | zero_flag);
2337                 if (!page)
2338                         goto out;
2339
2340                 sg_set_page(&sg[i], page, page_len, 0);
2341                 length -= page_len;
2342                 i++;
2343         }
2344         *sgl = sg;
2345         *nents = nent;
2346         return 0;
2347
2348 out:
2349         while (i > 0) {
2350                 i--;
2351                 __free_page(sg_page(&sg[i]));
2352         }
2353         kfree(sg);
2354         return -ENOMEM;
2355 }
2356 EXPORT_SYMBOL(target_alloc_sgl);
2357
2358 /*
2359  * Allocate any required resources to execute the command.  For writes we
2360  * might not have the payload yet, so notify the fabric via a call to
2361  * ->write_pending instead. Otherwise place it on the execution queue.
2362  */
2363 sense_reason_t
2364 transport_generic_new_cmd(struct se_cmd *cmd)
2365 {
2366         unsigned long flags;
2367         int ret = 0;
2368         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2369
2370         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2371             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2372                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2373                                        cmd->prot_length, true, false);
2374                 if (ret < 0)
2375                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2376         }
2377
2378         /*
2379          * Determine is the TCM fabric module has already allocated physical
2380          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2381          * beforehand.
2382          */
2383         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2384             cmd->data_length) {
2385
2386                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2387                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2388                         u32 bidi_length;
2389
2390                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2391                                 bidi_length = cmd->t_task_nolb *
2392                                               cmd->se_dev->dev_attrib.block_size;
2393                         else
2394                                 bidi_length = cmd->data_length;
2395
2396                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2397                                                &cmd->t_bidi_data_nents,
2398                                                bidi_length, zero_flag, false);
2399                         if (ret < 0)
2400                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2401                 }
2402
2403                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2404                                        cmd->data_length, zero_flag, false);
2405                 if (ret < 0)
2406                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2407         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2408                     cmd->data_length) {
2409                 /*
2410                  * Special case for COMPARE_AND_WRITE with fabrics
2411                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2412                  */
2413                 u32 caw_length = cmd->t_task_nolb *
2414                                  cmd->se_dev->dev_attrib.block_size;
2415
2416                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2417                                        &cmd->t_bidi_data_nents,
2418                                        caw_length, zero_flag, false);
2419                 if (ret < 0)
2420                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2421         }
2422         /*
2423          * If this command is not a write we can execute it right here,
2424          * for write buffers we need to notify the fabric driver first
2425          * and let it call back once the write buffers are ready.
2426          */
2427         target_add_to_state_list(cmd);
2428         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2429                 target_execute_cmd(cmd);
2430                 return 0;
2431         }
2432
2433         spin_lock_irqsave(&cmd->t_state_lock, flags);
2434         cmd->t_state = TRANSPORT_WRITE_PENDING;
2435         /*
2436          * Determine if frontend context caller is requesting the stopping of
2437          * this command for frontend exceptions.
2438          */
2439         if (cmd->transport_state & CMD_T_STOP) {
2440                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2441                          __func__, __LINE__, cmd->tag);
2442
2443                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2444
2445                 complete_all(&cmd->t_transport_stop_comp);
2446                 return 0;
2447         }
2448         cmd->transport_state &= ~CMD_T_ACTIVE;
2449         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2450
2451         ret = cmd->se_tfo->write_pending(cmd);
2452         if (ret == -EAGAIN || ret == -ENOMEM)
2453                 goto queue_full;
2454
2455         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2456         WARN_ON(ret);
2457
2458         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2459
2460 queue_full:
2461         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2462         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2463         transport_handle_queue_full(cmd, cmd->se_dev);
2464         return 0;
2465 }
2466 EXPORT_SYMBOL(transport_generic_new_cmd);
2467
2468 static void transport_write_pending_qf(struct se_cmd *cmd)
2469 {
2470         int ret;
2471
2472         ret = cmd->se_tfo->write_pending(cmd);
2473         if (ret == -EAGAIN || ret == -ENOMEM) {
2474                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2475                          cmd);
2476                 transport_handle_queue_full(cmd, cmd->se_dev);
2477         }
2478 }
2479
2480 static bool
2481 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2482                            unsigned long *flags);
2483
2484 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2485 {
2486         unsigned long flags;
2487
2488         spin_lock_irqsave(&cmd->t_state_lock, flags);
2489         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2490         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2491 }
2492
2493 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2494 {
2495         int ret = 0;
2496         bool aborted = false, tas = false;
2497
2498         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2499                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2500                         target_wait_free_cmd(cmd, &aborted, &tas);
2501
2502                 if (!aborted || tas)
2503                         ret = transport_put_cmd(cmd);
2504         } else {
2505                 if (wait_for_tasks)
2506                         target_wait_free_cmd(cmd, &aborted, &tas);
2507                 /*
2508                  * Handle WRITE failure case where transport_generic_new_cmd()
2509                  * has already added se_cmd to state_list, but fabric has
2510                  * failed command before I/O submission.
2511                  */
2512                 if (cmd->state_active)
2513                         target_remove_from_state_list(cmd);
2514
2515                 if (cmd->se_lun)
2516                         transport_lun_remove_cmd(cmd);
2517
2518                 if (!aborted || tas)
2519                         ret = transport_put_cmd(cmd);
2520         }
2521         /*
2522          * If the task has been internally aborted due to TMR ABORT_TASK
2523          * or LUN_RESET, target_core_tmr.c is responsible for performing
2524          * the remaining calls to target_put_sess_cmd(), and not the
2525          * callers of this function.
2526          */
2527         if (aborted) {
2528                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2529                 wait_for_completion(&cmd->cmd_wait_comp);
2530                 cmd->se_tfo->release_cmd(cmd);
2531                 ret = 1;
2532         }
2533         return ret;
2534 }
2535 EXPORT_SYMBOL(transport_generic_free_cmd);
2536
2537 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2538  * @se_cmd:     command descriptor to add
2539  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2540  */
2541 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2542 {
2543         struct se_session *se_sess = se_cmd->se_sess;
2544         unsigned long flags;
2545         int ret = 0;
2546
2547         /*
2548          * Add a second kref if the fabric caller is expecting to handle
2549          * fabric acknowledgement that requires two target_put_sess_cmd()
2550          * invocations before se_cmd descriptor release.
2551          */
2552         if (ack_kref) {
2553                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2554                         return -EINVAL;
2555
2556                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2557         }
2558
2559         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2560         if (se_sess->sess_tearing_down) {
2561                 ret = -ESHUTDOWN;
2562                 goto out;
2563         }
2564         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2565 out:
2566         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2567
2568         if (ret && ack_kref)
2569                 target_put_sess_cmd(se_cmd);
2570
2571         return ret;
2572 }
2573 EXPORT_SYMBOL(target_get_sess_cmd);
2574
2575 static void target_free_cmd_mem(struct se_cmd *cmd)
2576 {
2577         transport_free_pages(cmd);
2578
2579         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2580                 core_tmr_release_req(cmd->se_tmr_req);
2581         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2582                 kfree(cmd->t_task_cdb);
2583 }
2584
2585 static void target_release_cmd_kref(struct kref *kref)
2586 {
2587         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2588         struct se_session *se_sess = se_cmd->se_sess;
2589         unsigned long flags;
2590         bool fabric_stop;
2591
2592         if (se_sess) {
2593                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2594
2595                 spin_lock(&se_cmd->t_state_lock);
2596                 fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2597                               (se_cmd->transport_state & CMD_T_ABORTED);
2598                 spin_unlock(&se_cmd->t_state_lock);
2599
2600                 if (se_cmd->cmd_wait_set || fabric_stop) {
2601                         list_del_init(&se_cmd->se_cmd_list);
2602                         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2603                         target_free_cmd_mem(se_cmd);
2604                         complete(&se_cmd->cmd_wait_comp);
2605                         return;
2606                 }
2607                 list_del_init(&se_cmd->se_cmd_list);
2608                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2609         }
2610
2611         target_free_cmd_mem(se_cmd);
2612         se_cmd->se_tfo->release_cmd(se_cmd);
2613 }
2614
2615 /**
2616  * target_put_sess_cmd - decrease the command reference count
2617  * @se_cmd:     command to drop a reference from
2618  *
2619  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2620  * refcount to drop to zero. Returns zero otherwise.
2621  */
2622 int target_put_sess_cmd(struct se_cmd *se_cmd)
2623 {
2624         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2625 }
2626 EXPORT_SYMBOL(target_put_sess_cmd);
2627
2628 /* target_sess_cmd_list_set_waiting - Flag all commands in
2629  *         sess_cmd_list to complete cmd_wait_comp.  Set
2630  *         sess_tearing_down so no more commands are queued.
2631  * @se_sess:    session to flag
2632  */
2633 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2634 {
2635         struct se_cmd *se_cmd, *tmp_cmd;
2636         unsigned long flags;
2637         int rc;
2638
2639         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2640         if (se_sess->sess_tearing_down) {
2641                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2642                 return;
2643         }
2644         se_sess->sess_tearing_down = 1;
2645         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2646
2647         list_for_each_entry_safe(se_cmd, tmp_cmd,
2648                                  &se_sess->sess_wait_list, se_cmd_list) {
2649                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2650                 if (rc) {
2651                         se_cmd->cmd_wait_set = 1;
2652                         spin_lock(&se_cmd->t_state_lock);
2653                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2654                         spin_unlock(&se_cmd->t_state_lock);
2655                 } else
2656                         list_del_init(&se_cmd->se_cmd_list);
2657         }
2658
2659         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2660 }
2661 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2662
2663 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2664  * @se_sess:    session to wait for active I/O
2665  */
2666 void target_wait_for_sess_cmds(struct se_session *se_sess)
2667 {
2668         struct se_cmd *se_cmd, *tmp_cmd;
2669         unsigned long flags;
2670         bool tas;
2671
2672         list_for_each_entry_safe(se_cmd, tmp_cmd,
2673                                 &se_sess->sess_wait_list, se_cmd_list) {
2674                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2675                         " %d\n", se_cmd, se_cmd->t_state,
2676                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2677
2678                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2679                 tas = (se_cmd->transport_state & CMD_T_TAS);
2680                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2681
2682                 if (!target_put_sess_cmd(se_cmd)) {
2683                         if (tas)
2684                                 target_put_sess_cmd(se_cmd);
2685                 }
2686
2687                 wait_for_completion(&se_cmd->cmd_wait_comp);
2688                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2689                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2690                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2691
2692                 se_cmd->se_tfo->release_cmd(se_cmd);
2693         }
2694
2695         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2696         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2697         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2698
2699 }
2700 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2701
2702 static void target_lun_confirm(struct percpu_ref *ref)
2703 {
2704         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2705
2706         complete(&lun->lun_ref_comp);
2707 }
2708
2709 void transport_clear_lun_ref(struct se_lun *lun)
2710 {
2711         /*
2712          * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2713          * the initial reference and schedule confirm kill to be
2714          * executed after one full RCU grace period has completed.
2715          */
2716         percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2717         /*
2718          * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2719          * to call target_lun_confirm after lun->lun_ref has been marked
2720          * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2721          * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2722          * fails for all new incoming I/O.
2723          */
2724         wait_for_completion(&lun->lun_ref_comp);
2725         /*
2726          * The second completion waits for percpu_ref_put_many() to
2727          * invoke ->release() after lun->lun_ref has switched to
2728          * atomic_t mode, and lun->lun_ref.count has reached zero.
2729          *
2730          * At this point all target-core lun->lun_ref references have
2731          * been dropped via transport_lun_remove_cmd(), and it's safe
2732          * to proceed with the remaining LUN shutdown.
2733          */
2734         wait_for_completion(&lun->lun_shutdown_comp);
2735 }
2736
2737 static bool
2738 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2739                            bool *aborted, bool *tas, unsigned long *flags)
2740         __releases(&cmd->t_state_lock)
2741         __acquires(&cmd->t_state_lock)
2742 {
2743
2744         assert_spin_locked(&cmd->t_state_lock);
2745         WARN_ON_ONCE(!irqs_disabled());
2746
2747         if (fabric_stop)
2748                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2749
2750         if (cmd->transport_state & CMD_T_ABORTED)
2751                 *aborted = true;
2752
2753         if (cmd->transport_state & CMD_T_TAS)
2754                 *tas = true;
2755
2756         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2757             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2758                 return false;
2759
2760         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2761             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2762                 return false;
2763
2764         if (!(cmd->transport_state & CMD_T_ACTIVE))
2765                 return false;
2766
2767         if (fabric_stop && *aborted)
2768                 return false;
2769
2770         cmd->transport_state |= CMD_T_STOP;
2771
2772         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2773                  " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2774                  cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2775
2776         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2777
2778         wait_for_completion(&cmd->t_transport_stop_comp);
2779
2780         spin_lock_irqsave(&cmd->t_state_lock, *flags);
2781         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2782
2783         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2784                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2785
2786         return true;
2787 }
2788
2789 /**
2790  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
2791  * @cmd: command to wait on
2792  */
2793 bool transport_wait_for_tasks(struct se_cmd *cmd)
2794 {
2795         unsigned long flags;
2796         bool ret, aborted = false, tas = false;
2797
2798         spin_lock_irqsave(&cmd->t_state_lock, flags);
2799         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2800         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2801
2802         return ret;
2803 }
2804 EXPORT_SYMBOL(transport_wait_for_tasks);
2805
2806 struct sense_info {
2807         u8 key;
2808         u8 asc;
2809         u8 ascq;
2810         bool add_sector_info;
2811 };
2812
2813 static const struct sense_info sense_info_table[] = {
2814         [TCM_NO_SENSE] = {
2815                 .key = NOT_READY
2816         },
2817         [TCM_NON_EXISTENT_LUN] = {
2818                 .key = ILLEGAL_REQUEST,
2819                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2820         },
2821         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
2822                 .key = ILLEGAL_REQUEST,
2823                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2824         },
2825         [TCM_SECTOR_COUNT_TOO_MANY] = {
2826                 .key = ILLEGAL_REQUEST,
2827                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2828         },
2829         [TCM_UNKNOWN_MODE_PAGE] = {
2830                 .key = ILLEGAL_REQUEST,
2831                 .asc = 0x24, /* INVALID FIELD IN CDB */
2832         },
2833         [TCM_CHECK_CONDITION_ABORT_CMD] = {
2834                 .key = ABORTED_COMMAND,
2835                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2836                 .ascq = 0x03,
2837         },
2838         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
2839                 .key = ABORTED_COMMAND,
2840                 .asc = 0x0c, /* WRITE ERROR */
2841                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2842         },
2843         [TCM_INVALID_CDB_FIELD] = {
2844                 .key = ILLEGAL_REQUEST,
2845                 .asc = 0x24, /* INVALID FIELD IN CDB */
2846         },
2847         [TCM_INVALID_PARAMETER_LIST] = {
2848                 .key = ILLEGAL_REQUEST,
2849                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2850         },
2851         [TCM_TOO_MANY_TARGET_DESCS] = {
2852                 .key = ILLEGAL_REQUEST,
2853                 .asc = 0x26,
2854                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
2855         },
2856         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
2857                 .key = ILLEGAL_REQUEST,
2858                 .asc = 0x26,
2859                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
2860         },
2861         [TCM_TOO_MANY_SEGMENT_DESCS] = {
2862                 .key = ILLEGAL_REQUEST,
2863                 .asc = 0x26,
2864                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
2865         },
2866         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
2867                 .key = ILLEGAL_REQUEST,
2868                 .asc = 0x26,
2869                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
2870         },
2871         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2872                 .key = ILLEGAL_REQUEST,
2873                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2874         },
2875         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2876                 .key = ILLEGAL_REQUEST,
2877                 .asc = 0x0c, /* WRITE ERROR */
2878                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2879         },
2880         [TCM_SERVICE_CRC_ERROR] = {
2881                 .key = ABORTED_COMMAND,
2882                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2883                 .ascq = 0x05, /* N/A */
2884         },
2885         [TCM_SNACK_REJECTED] = {
2886                 .key = ABORTED_COMMAND,
2887                 .asc = 0x11, /* READ ERROR */
2888                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2889         },
2890         [TCM_WRITE_PROTECTED] = {
2891                 .key = DATA_PROTECT,
2892                 .asc = 0x27, /* WRITE PROTECTED */
2893         },
2894         [TCM_ADDRESS_OUT_OF_RANGE] = {
2895                 .key = ILLEGAL_REQUEST,
2896                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2897         },
2898         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2899                 .key = UNIT_ATTENTION,
2900         },
2901         [TCM_CHECK_CONDITION_NOT_READY] = {
2902                 .key = NOT_READY,
2903         },
2904         [TCM_MISCOMPARE_VERIFY] = {
2905                 .key = MISCOMPARE,
2906                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2907                 .ascq = 0x00,
2908         },
2909         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2910                 .key = ABORTED_COMMAND,
2911                 .asc = 0x10,
2912                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2913                 .add_sector_info = true,
2914         },
2915         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2916                 .key = ABORTED_COMMAND,
2917                 .asc = 0x10,
2918                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2919                 .add_sector_info = true,
2920         },
2921         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2922                 .key = ABORTED_COMMAND,
2923                 .asc = 0x10,
2924                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2925                 .add_sector_info = true,
2926         },
2927         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
2928                 .key = COPY_ABORTED,
2929                 .asc = 0x0d,
2930                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
2931
2932         },
2933         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2934                 /*
2935                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2936                  * Solaris initiators.  Returning NOT READY instead means the
2937                  * operations will be retried a finite number of times and we
2938                  * can survive intermittent errors.
2939                  */
2940                 .key = NOT_READY,
2941                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2942         },
2943 };
2944
2945 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2946 {
2947         const struct sense_info *si;
2948         u8 *buffer = cmd->sense_buffer;
2949         int r = (__force int)reason;
2950         u8 asc, ascq;
2951         bool desc_format = target_sense_desc_format(cmd->se_dev);
2952
2953         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2954                 si = &sense_info_table[r];
2955         else
2956                 si = &sense_info_table[(__force int)
2957                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2958
2959         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2960                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2961                 WARN_ON_ONCE(asc == 0);
2962         } else if (si->asc == 0) {
2963                 WARN_ON_ONCE(cmd->scsi_asc == 0);
2964                 asc = cmd->scsi_asc;
2965                 ascq = cmd->scsi_ascq;
2966         } else {
2967                 asc = si->asc;
2968                 ascq = si->ascq;
2969         }
2970
2971         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2972         if (si->add_sector_info)
2973                 return scsi_set_sense_information(buffer,
2974                                                   cmd->scsi_sense_length,
2975                                                   cmd->bad_sector);
2976
2977         return 0;
2978 }
2979
2980 int
2981 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2982                 sense_reason_t reason, int from_transport)
2983 {
2984         unsigned long flags;
2985
2986         spin_lock_irqsave(&cmd->t_state_lock, flags);
2987         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2988                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2989                 return 0;
2990         }
2991         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2992         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2993
2994         if (!from_transport) {
2995                 int rc;
2996
2997                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2998                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2999                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3000                 rc = translate_sense_reason(cmd, reason);
3001                 if (rc)
3002                         return rc;
3003         }
3004
3005         trace_target_cmd_complete(cmd);
3006         return cmd->se_tfo->queue_status(cmd);
3007 }
3008 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3009
3010 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3011         __releases(&cmd->t_state_lock)
3012         __acquires(&cmd->t_state_lock)
3013 {
3014         assert_spin_locked(&cmd->t_state_lock);
3015         WARN_ON_ONCE(!irqs_disabled());
3016
3017         if (!(cmd->transport_state & CMD_T_ABORTED))
3018                 return 0;
3019         /*
3020          * If cmd has been aborted but either no status is to be sent or it has
3021          * already been sent, just return
3022          */
3023         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3024                 if (send_status)
3025                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3026                 return 1;
3027         }
3028
3029         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3030                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3031
3032         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3033         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3034         trace_target_cmd_complete(cmd);
3035
3036         spin_unlock_irq(&cmd->t_state_lock);
3037         cmd->se_tfo->queue_status(cmd);
3038         spin_lock_irq(&cmd->t_state_lock);
3039
3040         return 1;
3041 }
3042
3043 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3044 {
3045         int ret;
3046
3047         spin_lock_irq(&cmd->t_state_lock);
3048         ret = __transport_check_aborted_status(cmd, send_status);
3049         spin_unlock_irq(&cmd->t_state_lock);
3050
3051         return ret;
3052 }
3053 EXPORT_SYMBOL(transport_check_aborted_status);
3054
3055 void transport_send_task_abort(struct se_cmd *cmd)
3056 {
3057         unsigned long flags;
3058
3059         spin_lock_irqsave(&cmd->t_state_lock, flags);
3060         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3061                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3062                 return;
3063         }
3064         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3065
3066         /*
3067          * If there are still expected incoming fabric WRITEs, we wait
3068          * until until they have completed before sending a TASK_ABORTED
3069          * response.  This response with TASK_ABORTED status will be
3070          * queued back to fabric module by transport_check_aborted_status().
3071          */
3072         if (cmd->data_direction == DMA_TO_DEVICE) {
3073                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3074                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3075                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3076                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3077                                 goto send_abort;
3078                         }
3079                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3080                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3081                         return;
3082                 }
3083         }
3084 send_abort:
3085         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3086
3087         transport_lun_remove_cmd(cmd);
3088
3089         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3090                  cmd->t_task_cdb[0], cmd->tag);
3091
3092         trace_target_cmd_complete(cmd);
3093         cmd->se_tfo->queue_status(cmd);
3094 }
3095
3096 static void target_tmr_work(struct work_struct *work)
3097 {
3098         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3099         struct se_device *dev = cmd->se_dev;
3100         struct se_tmr_req *tmr = cmd->se_tmr_req;
3101         unsigned long flags;
3102         int ret;
3103
3104         spin_lock_irqsave(&cmd->t_state_lock, flags);
3105         if (cmd->transport_state & CMD_T_ABORTED) {
3106                 tmr->response = TMR_FUNCTION_REJECTED;
3107                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3108                 goto check_stop;
3109         }
3110         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3111
3112         switch (tmr->function) {
3113         case TMR_ABORT_TASK:
3114                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3115                 break;
3116         case TMR_ABORT_TASK_SET:
3117         case TMR_CLEAR_ACA:
3118         case TMR_CLEAR_TASK_SET:
3119                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3120                 break;
3121         case TMR_LUN_RESET:
3122                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3123                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3124                                          TMR_FUNCTION_REJECTED;
3125                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3126                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3127                                                cmd->orig_fe_lun, 0x29,
3128                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3129                 }
3130                 break;
3131         case TMR_TARGET_WARM_RESET:
3132                 tmr->response = TMR_FUNCTION_REJECTED;
3133                 break;
3134         case TMR_TARGET_COLD_RESET:
3135                 tmr->response = TMR_FUNCTION_REJECTED;
3136                 break;
3137         default:
3138                 pr_err("Uknown TMR function: 0x%02x.\n",
3139                                 tmr->function);
3140                 tmr->response = TMR_FUNCTION_REJECTED;
3141                 break;
3142         }
3143
3144         spin_lock_irqsave(&cmd->t_state_lock, flags);
3145         if (cmd->transport_state & CMD_T_ABORTED) {
3146                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3147                 goto check_stop;
3148         }
3149         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3150
3151         cmd->se_tfo->queue_tm_rsp(cmd);
3152
3153 check_stop:
3154         transport_cmd_check_stop_to_fabric(cmd);
3155 }
3156
3157 int transport_generic_handle_tmr(
3158         struct se_cmd *cmd)
3159 {
3160         unsigned long flags;
3161         bool aborted = false;
3162
3163         spin_lock_irqsave(&cmd->t_state_lock, flags);
3164         if (cmd->transport_state & CMD_T_ABORTED) {
3165                 aborted = true;
3166         } else {
3167                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3168                 cmd->transport_state |= CMD_T_ACTIVE;
3169         }
3170         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3171
3172         if (aborted) {
3173                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3174                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3175                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3176                 transport_cmd_check_stop_to_fabric(cmd);
3177                 return 0;
3178         }
3179
3180         INIT_WORK(&cmd->work, target_tmr_work);
3181         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3182         return 0;
3183 }
3184 EXPORT_SYMBOL(transport_generic_handle_tmr);
3185
3186 bool
3187 target_check_wce(struct se_device *dev)
3188 {
3189         bool wce = false;
3190
3191         if (dev->transport->get_write_cache)
3192                 wce = dev->transport->get_write_cache(dev);
3193         else if (dev->dev_attrib.emulate_write_cache > 0)
3194                 wce = true;
3195
3196         return wce;
3197 }
3198
3199 bool
3200 target_check_fua(struct se_device *dev)
3201 {
3202         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3203 }