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