drivers/target/target_core_transport.c

   1 /*******************************************************************************
   2  * Filename:  target_core_transport.c
   3  *
   4  * This file contains the Generic Target Engine Core.
   5  *
   6  * (c) Copyright 2002-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/net.h>
  27 #include <linux/delay.h>
  28 #include <linux/string.h>
  29 #include <linux/timer.h>
  30 #include <linux/slab.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/kthread.h>
  33 #include <linux/in.h>
  34 #include <linux/cdrom.h>
  35 #include <linux/module.h>
  36 #include <linux/ratelimit.h>
  37 #include <linux/vmalloc.h>
  38 #include <asm/unaligned.h>
  39 #include <net/sock.h>
  40 #include <net/tcp.h>
  41 #include <scsi/scsi_proto.h>
  42 #include <scsi/scsi_common.h>
  43
  44 #include <target/target_core_base.h>
  45 #include <target/target_core_backend.h>
  46 #include <target/target_core_fabric.h>
  47
  48 #include "target_core_internal.h"
  49 #include "target_core_alua.h"
  50 #include "target_core_pr.h"
  51 #include "target_core_ua.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/target.h>
  55
  56 static struct workqueue_struct *target_completion_wq;
  57 static struct kmem_cache *se_sess_cache;
  58 struct kmem_cache *se_ua_cache;
  59 struct kmem_cache *t10_pr_reg_cache;
  60 struct kmem_cache *t10_alua_lu_gp_cache;
  61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  63 struct kmem_cache *t10_alua_lba_map_cache;
  64 struct kmem_cache *t10_alua_lba_map_mem_cache;
  65
  66 static void transport_complete_task_attr(struct se_cmd *cmd);
  67 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
  68 static void transport_handle_queue_full(struct se_cmd *cmd,
  69                 struct se_device *dev, int err, bool write_pending);
  70 static void target_complete_ok_work(struct work_struct *work);
  71
  72 int init_se_kmem_caches(void)
  73 {
  74         se_sess_cache = kmem_cache_create("se_sess_cache",
  75                         sizeof(struct se_session), __alignof__(struct se_session),
  76                         0, NULL);
  77         if (!se_sess_cache) {
  78                 pr_err("kmem_cache_create() for struct se_session"
  79                                 " failed\n");
  80                 goto out;
  81         }
  82         se_ua_cache = kmem_cache_create("se_ua_cache",
  83                         sizeof(struct se_ua), __alignof__(struct se_ua),
  84                         0, NULL);
  85         if (!se_ua_cache) {
  86                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  87                 goto out_free_sess_cache;
  88         }
  89         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  90                         sizeof(struct t10_pr_registration),
  91                         __alignof__(struct t10_pr_registration), 0, NULL);
  92         if (!t10_pr_reg_cache) {
  93                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  94                                 " failed\n");
  95                 goto out_free_ua_cache;
  96         }
  97         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  98                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  99                         0, NULL);
 100         if (!t10_alua_lu_gp_cache) {
 101                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 102                                 " failed\n");
 103                 goto out_free_pr_reg_cache;
 104         }
 105         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 106                         sizeof(struct t10_alua_lu_gp_member),
 107                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 108         if (!t10_alua_lu_gp_mem_cache) {
 109                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 110                                 "cache failed\n");
 111                 goto out_free_lu_gp_cache;
 112         }
 113         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 114                         sizeof(struct t10_alua_tg_pt_gp),
 115                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 116         if (!t10_alua_tg_pt_gp_cache) {
 117                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 118                                 "cache failed\n");
 119                 goto out_free_lu_gp_mem_cache;
 120         }
 121         t10_alua_lba_map_cache = kmem_cache_create(
 122                         "t10_alua_lba_map_cache",
 123                         sizeof(struct t10_alua_lba_map),
 124                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 125         if (!t10_alua_lba_map_cache) {
 126                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 127                                 "cache failed\n");
 128                 goto out_free_tg_pt_gp_cache;
 129         }
 130         t10_alua_lba_map_mem_cache = kmem_cache_create(
 131                         "t10_alua_lba_map_mem_cache",
 132                         sizeof(struct t10_alua_lba_map_member),
 133                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 134         if (!t10_alua_lba_map_mem_cache) {
 135                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 136                                 "cache failed\n");
 137                 goto out_free_lba_map_cache;
 138         }
 139
 140         target_completion_wq = alloc_workqueue("target_completion",
 141                                                WQ_MEM_RECLAIM, 0);
 142         if (!target_completion_wq)
 143                 goto out_free_lba_map_mem_cache;
 144
 145         return 0;
 146
 147 out_free_lba_map_mem_cache:
 148         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 149 out_free_lba_map_cache:
 150         kmem_cache_destroy(t10_alua_lba_map_cache);
 151 out_free_tg_pt_gp_cache:
 152         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 153 out_free_lu_gp_mem_cache:
 154         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 155 out_free_lu_gp_cache:
 156         kmem_cache_destroy(t10_alua_lu_gp_cache);
 157 out_free_pr_reg_cache:
 158         kmem_cache_destroy(t10_pr_reg_cache);
 159 out_free_ua_cache:
 160         kmem_cache_destroy(se_ua_cache);
 161 out_free_sess_cache:
 162         kmem_cache_destroy(se_sess_cache);
 163 out:
 164         return -ENOMEM;
 165 }
 166
 167 void release_se_kmem_caches(void)
 168 {
 169         destroy_workqueue(target_completion_wq);
 170         kmem_cache_destroy(se_sess_cache);
 171         kmem_cache_destroy(se_ua_cache);
 172         kmem_cache_destroy(t10_pr_reg_cache);
 173         kmem_cache_destroy(t10_alua_lu_gp_cache);
 174         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 175         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 176         kmem_cache_destroy(t10_alua_lba_map_cache);
 177         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 178 }
 179
 180 /* This code ensures unique mib indexes are handed out. */
 181 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 182 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 183
 184 /*
 185  * Allocate a new row index for the entry type specified
 186  */
 187 u32 scsi_get_new_index(scsi_index_t type)
 188 {
 189         u32 new_index;
 190
 191         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 192
 193         spin_lock(&scsi_mib_index_lock);
 194         new_index = ++scsi_mib_index[type];
 195         spin_unlock(&scsi_mib_index_lock);
 196
 197         return new_index;
 198 }
 199
 200 void transport_subsystem_check_init(void)
 201 {
 202         int ret;
 203         static int sub_api_initialized;
 204
 205         if (sub_api_initialized)
 206                 return;
 207
 208         ret = request_module("target_core_iblock");
 209         if (ret != 0)
 210                 pr_err("Unable to load target_core_iblock\n");
 211
 212         ret = request_module("target_core_file");
 213         if (ret != 0)
 214                 pr_err("Unable to load target_core_file\n");
 215
 216         ret = request_module("target_core_pscsi");
 217         if (ret != 0)
 218                 pr_err("Unable to load target_core_pscsi\n");
 219
 220         ret = request_module("target_core_user");
 221         if (ret != 0)
 222                 pr_err("Unable to load target_core_user\n");
 223
 224         sub_api_initialized = 1;
 225 }
 226
 227 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
 228 {
 229         struct se_session *se_sess;
 230
 231         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 232         if (!se_sess) {
 233                 pr_err("Unable to allocate struct se_session from"
 234                                 " se_sess_cache\n");
 235                 return ERR_PTR(-ENOMEM);
 236         }
 237         INIT_LIST_HEAD(&se_sess->sess_list);
 238         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 239         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 240         INIT_LIST_HEAD(&se_sess->sess_wait_list);
 241         spin_lock_init(&se_sess->sess_cmd_lock);
 242         se_sess->sup_prot_ops = sup_prot_ops;
 243
 244         return se_sess;
 245 }
 246 EXPORT_SYMBOL(transport_init_session);
 247
 248 int transport_alloc_session_tags(struct se_session *se_sess,
 249                                  unsigned int tag_num, unsigned int tag_size)
 250 {
 251         int rc;
 252
 253         se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
 254                                         GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);
 255         if (!se_sess->sess_cmd_map) {
 256                 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
 257                 if (!se_sess->sess_cmd_map) {
 258                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 259                         return -ENOMEM;
 260                 }
 261         }
 262
 263         rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
 264         if (rc < 0) {
 265                 pr_err("Unable to init se_sess->sess_tag_pool,"
 266                         " tag_num: %u\n", tag_num);
 267                 kvfree(se_sess->sess_cmd_map);
 268                 se_sess->sess_cmd_map = NULL;
 269                 return -ENOMEM;
 270         }
 271
 272         return 0;
 273 }
 274 EXPORT_SYMBOL(transport_alloc_session_tags);
 275
 276 struct se_session *transport_init_session_tags(unsigned int tag_num,
 277                                                unsigned int tag_size,
 278                                                enum target_prot_op sup_prot_ops)
 279 {
 280         struct se_session *se_sess;
 281         int rc;
 282
 283         if (tag_num != 0 && !tag_size) {
 284                 pr_err("init_session_tags called with percpu-ida tag_num:"
 285                        " %u, but zero tag_size\n", tag_num);
 286                 return ERR_PTR(-EINVAL);
 287         }
 288         if (!tag_num && tag_size) {
 289                 pr_err("init_session_tags called with percpu-ida tag_size:"
 290                        " %u, but zero tag_num\n", tag_size);
 291                 return ERR_PTR(-EINVAL);
 292         }
 293
 294         se_sess = transport_init_session(sup_prot_ops);
 295         if (IS_ERR(se_sess))
 296                 return se_sess;
 297
 298         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 299         if (rc < 0) {
 300                 transport_free_session(se_sess);
 301                 return ERR_PTR(-ENOMEM);
 302         }
 303
 304         return se_sess;
 305 }
 306 EXPORT_SYMBOL(transport_init_session_tags);
 307
 308 /*
 309  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 310  */
 311 void __transport_register_session(
 312         struct se_portal_group *se_tpg,
 313         struct se_node_acl *se_nacl,
 314         struct se_session *se_sess,
 315         void *fabric_sess_ptr)
 316 {
 317         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 318         unsigned char buf[PR_REG_ISID_LEN];
 319
 320         se_sess->se_tpg = se_tpg;
 321         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 322         /*
 323          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 324          *
 325          * Only set for struct se_session's that will actually be moving I/O.
 326          * eg: *NOT* discovery sessions.
 327          */
 328         if (se_nacl) {
 329                 /*
 330                  *
 331                  * Determine if fabric allows for T10-PI feature bits exposed to
 332                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 333                  *
 334                  * If so, then always save prot_type on a per se_node_acl node
 335                  * basis and re-instate the previous sess_prot_type to avoid
 336                  * disabling PI from below any previously initiator side
 337                  * registered LUNs.
 338                  */
 339                 if (se_nacl->saved_prot_type)
 340                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 341                 else if (tfo->tpg_check_prot_fabric_only)
 342                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 343                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 344                 /*
 345                  * If the fabric module supports an ISID based TransportID,
 346                  * save this value in binary from the fabric I_T Nexus now.
 347                  */
 348                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 349                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 350                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 351                                         &buf[0], PR_REG_ISID_LEN);
 352                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 353                 }
 354
 355                 spin_lock_irq(&se_nacl->nacl_sess_lock);
 356                 /*
 357                  * The se_nacl->nacl_sess pointer will be set to the
 358                  * last active I_T Nexus for each struct se_node_acl.
 359                  */
 360                 se_nacl->nacl_sess = se_sess;
 361
 362                 list_add_tail(&se_sess->sess_acl_list,
 363                               &se_nacl->acl_sess_list);
 364                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
 365         }
 366         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 367
 368         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 369                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 370 }
 371 EXPORT_SYMBOL(__transport_register_session);
 372
 373 void transport_register_session(
 374         struct se_portal_group *se_tpg,
 375         struct se_node_acl *se_nacl,
 376         struct se_session *se_sess,
 377         void *fabric_sess_ptr)
 378 {
 379         unsigned long flags;
 380
 381         spin_lock_irqsave(&se_tpg->session_lock, flags);
 382         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 383         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 384 }
 385 EXPORT_SYMBOL(transport_register_session);
 386
 387 struct se_session *
 388 target_alloc_session(struct se_portal_group *tpg,
 389                      unsigned int tag_num, unsigned int tag_size,
 390                      enum target_prot_op prot_op,
 391                      const char *initiatorname, void *private,
 392                      int (*callback)(struct se_portal_group *,
 393                                      struct se_session *, void *))
 394 {
 395         struct se_session *sess;
 396
 397         /*
 398          * If the fabric driver is using percpu-ida based pre allocation
 399          * of I/O descriptor tags, go ahead and perform that setup now..
 400          */
 401         if (tag_num != 0)
 402                 sess = transport_init_session_tags(tag_num, tag_size, prot_op);
 403         else
 404                 sess = transport_init_session(prot_op);
 405
 406         if (IS_ERR(sess))
 407                 return sess;
 408
 409         sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
 410                                         (unsigned char *)initiatorname);
 411         if (!sess->se_node_acl) {
 412                 transport_free_session(sess);
 413                 return ERR_PTR(-EACCES);
 414         }
 415         /*
 416          * Go ahead and perform any remaining fabric setup that is
 417          * required before transport_register_session().
 418          */
 419         if (callback != NULL) {
 420                 int rc = callback(tpg, sess, private);
 421                 if (rc) {
 422                         transport_free_session(sess);
 423                         return ERR_PTR(rc);
 424                 }
 425         }
 426
 427         transport_register_session(tpg, sess->se_node_acl, sess, private);
 428         return sess;
 429 }
 430 EXPORT_SYMBOL(target_alloc_session);
 431
 432 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 433 {
 434         struct se_session *se_sess;
 435         ssize_t len = 0;
 436
 437         spin_lock_bh(&se_tpg->session_lock);
 438         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 439                 if (!se_sess->se_node_acl)
 440                         continue;
 441                 if (!se_sess->se_node_acl->dynamic_node_acl)
 442                         continue;
 443                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 444                         break;
 445
 446                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 447                                 se_sess->se_node_acl->initiatorname);
 448                 len += 1; /* Include NULL terminator */
 449         }
 450         spin_unlock_bh(&se_tpg->session_lock);
 451
 452         return len;
 453 }
 454 EXPORT_SYMBOL(target_show_dynamic_sessions);
 455
 456 static void target_complete_nacl(struct kref *kref)
 457 {
 458         struct se_node_acl *nacl = container_of(kref,
 459                                 struct se_node_acl, acl_kref);
 460         struct se_portal_group *se_tpg = nacl->se_tpg;
 461
 462         if (!nacl->dynamic_stop) {
 463                 complete(&nacl->acl_free_comp);
 464                 return;
 465         }
 466
 467         mutex_lock(&se_tpg->acl_node_mutex);
 468         list_del_init(&nacl->acl_list);
 469         mutex_unlock(&se_tpg->acl_node_mutex);
 470
 471         core_tpg_wait_for_nacl_pr_ref(nacl);
 472         core_free_device_list_for_node(nacl, se_tpg);
 473         kfree(nacl);
 474 }
 475
 476 void target_put_nacl(struct se_node_acl *nacl)
 477 {
 478         kref_put(&nacl->acl_kref, target_complete_nacl);
 479 }
 480 EXPORT_SYMBOL(target_put_nacl);
 481
 482 void transport_deregister_session_configfs(struct se_session *se_sess)
 483 {
 484         struct se_node_acl *se_nacl;
 485         unsigned long flags;
 486         /*
 487          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 488          */
 489         se_nacl = se_sess->se_node_acl;
 490         if (se_nacl) {
 491                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 492                 if (!list_empty(&se_sess->sess_acl_list))
 493                         list_del_init(&se_sess->sess_acl_list);
 494                 /*
 495                  * If the session list is empty, then clear the pointer.
 496                  * Otherwise, set the struct se_session pointer from the tail
 497                  * element of the per struct se_node_acl active session list.
 498                  */
 499                 if (list_empty(&se_nacl->acl_sess_list))
 500                         se_nacl->nacl_sess = NULL;
 501                 else {
 502                         se_nacl->nacl_sess = container_of(
 503                                         se_nacl->acl_sess_list.prev,
 504                                         struct se_session, sess_acl_list);
 505                 }
 506                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 507         }
 508 }
 509 EXPORT_SYMBOL(transport_deregister_session_configfs);
 510
 511 void transport_free_session(struct se_session *se_sess)
 512 {
 513         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 514
 515         /*
 516          * Drop the se_node_acl->nacl_kref obtained from within
 517          * core_tpg_get_initiator_node_acl().
 518          */
 519         if (se_nacl) {
 520                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 521                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 522                 unsigned long flags;
 523
 524                 se_sess->se_node_acl = NULL;
 525
 526                 /*
 527                  * Also determine if we need to drop the extra ->cmd_kref if
 528                  * it had been previously dynamically generated, and
 529                  * the endpoint is not caching dynamic ACLs.
 530                  */
 531                 mutex_lock(&se_tpg->acl_node_mutex);
 532                 if (se_nacl->dynamic_node_acl &&
 533                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 534                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 535                         if (list_empty(&se_nacl->acl_sess_list))
 536                                 se_nacl->dynamic_stop = true;
 537                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 538
 539                         if (se_nacl->dynamic_stop)
 540                                 list_del_init(&se_nacl->acl_list);
 541                 }
 542                 mutex_unlock(&se_tpg->acl_node_mutex);
 543
 544                 if (se_nacl->dynamic_stop)
 545                         target_put_nacl(se_nacl);
 546
 547                 target_put_nacl(se_nacl);
 548         }
 549         if (se_sess->sess_cmd_map) {
 550                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 551                 kvfree(se_sess->sess_cmd_map);
 552         }
 553         kmem_cache_free(se_sess_cache, se_sess);
 554 }
 555 EXPORT_SYMBOL(transport_free_session);
 556
 557 void transport_deregister_session(struct se_session *se_sess)
 558 {
 559         struct se_portal_group *se_tpg = se_sess->se_tpg;
 560         unsigned long flags;
 561
 562         if (!se_tpg) {
 563                 transport_free_session(se_sess);
 564                 return;
 565         }
 566
 567         spin_lock_irqsave(&se_tpg->session_lock, flags);
 568         list_del(&se_sess->sess_list);
 569         se_sess->se_tpg = NULL;
 570         se_sess->fabric_sess_ptr = NULL;
 571         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 572
 573         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 574                 se_tpg->se_tpg_tfo->get_fabric_name());
 575         /*
 576          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 577          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 578          * removal context from within transport_free_session() code.
 579          *
 580          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 581          * to release all remaining generate_node_acl=1 created ACL resources.
 582          */
 583
 584         transport_free_session(se_sess);
 585 }
 586 EXPORT_SYMBOL(transport_deregister_session);
 587
 588 static void target_remove_from_state_list(struct se_cmd *cmd)
 589 {
 590         struct se_device *dev = cmd->se_dev;
 591         unsigned long flags;
 592
 593         if (!dev)
 594                 return;
 595
 596         spin_lock_irqsave(&dev->execute_task_lock, flags);
 597         if (cmd->state_active) {
 598                 list_del(&cmd->state_list);
 599                 cmd->state_active = false;
 600         }
 601         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 602 }
 603
 604 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 605 {
 606         unsigned long flags;
 607
 608         target_remove_from_state_list(cmd);
 609
 610         /*
 611          * Clear struct se_cmd->se_lun before the handoff to FE.
 612          */
 613         cmd->se_lun = NULL;
 614
 615         spin_lock_irqsave(&cmd->t_state_lock, flags);
 616         /*
 617          * Determine if frontend context caller is requesting the stopping of
 618          * this command for frontend exceptions.
 619          */
 620         if (cmd->transport_state & CMD_T_STOP) {
 621                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 622                         __func__, __LINE__, cmd->tag);
 623
 624                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 625
 626                 complete_all(&cmd->t_transport_stop_comp);
 627                 return 1;
 628         }
 629         cmd->transport_state &= ~CMD_T_ACTIVE;
 630         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 631
 632         /*
 633          * Some fabric modules like tcm_loop can release their internally
 634          * allocated I/O reference and struct se_cmd now.
 635          *
 636          * Fabric modules are expected to return '1' here if the se_cmd being
 637          * passed is released at this point, or zero if not being released.
 638          */
 639         return cmd->se_tfo->check_stop_free(cmd);
 640 }
 641
 642 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 643 {
 644         struct se_lun *lun = cmd->se_lun;
 645
 646         if (!lun)
 647                 return;
 648
 649         if (cmpxchg(&cmd->lun_ref_active, true, false))
 650                 percpu_ref_put(&lun->lun_ref);
 651 }
 652
 653 int transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 654 {
 655         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 656         int ret = 0;
 657
 658         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 659                 transport_lun_remove_cmd(cmd);
 660         /*
 661          * Allow the fabric driver to unmap any resources before
 662          * releasing the descriptor via TFO->release_cmd()
 663          */
 664         if (remove)
 665                 cmd->se_tfo->aborted_task(cmd);
 666
 667         if (transport_cmd_check_stop_to_fabric(cmd))
 668                 return 1;
 669         if (remove && ack_kref)
 670                 ret = target_put_sess_cmd(cmd);
 671
 672         return ret;
 673 }
 674
 675 static void target_complete_failure_work(struct work_struct *work)
 676 {
 677         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 678
 679         transport_generic_request_failure(cmd,
 680                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 681 }
 682
 683 /*
 684  * Used when asking transport to copy Sense Data from the underlying
 685  * Linux/SCSI struct scsi_cmnd
 686  */
 687 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 688 {
 689         struct se_device *dev = cmd->se_dev;
 690
 691         WARN_ON(!cmd->se_lun);
 692
 693         if (!dev)
 694                 return NULL;
 695
 696         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 697                 return NULL;
 698
 699         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 700
 701         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 702                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 703         return cmd->sense_buffer;
 704 }
 705
 706 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
 707 {
 708         unsigned char *cmd_sense_buf;
 709         unsigned long flags;
 710
 711         spin_lock_irqsave(&cmd->t_state_lock, flags);
 712         cmd_sense_buf = transport_get_sense_buffer(cmd);
 713         if (!cmd_sense_buf) {
 714                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 715                 return;
 716         }
 717
 718         cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
 719         memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
 720         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 721 }
 722 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
 723
 724 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 725 {
 726         struct se_device *dev = cmd->se_dev;
 727         int success;
 728         unsigned long flags;
 729
 730         cmd->scsi_status = scsi_status;
 731
 732         spin_lock_irqsave(&cmd->t_state_lock, flags);
 733         switch (cmd->scsi_status) {
 734         case SAM_STAT_CHECK_CONDITION:
 735                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 736                         success = 1;
 737                 else
 738                         success = 0;
 739                 break;
 740         default:
 741                 success = 1;
 742                 break;
 743         }
 744
 745         /*
 746          * Check for case where an explicit ABORT_TASK has been received
 747          * and transport_wait_for_tasks() will be waiting for completion..
 748          */
 749         if (cmd->transport_state & CMD_T_ABORTED ||
 750             cmd->transport_state & CMD_T_STOP) {
 751                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 752                 /*
 753                  * If COMPARE_AND_WRITE was stopped by __transport_wait_for_tasks(),
 754                  * release se_device->caw_sem obtained by sbc_compare_and_write()
 755                  * since target_complete_ok_work() or target_complete_failure_work()
 756                  * won't be called to invoke the normal CAW completion callbacks.
 757                  */
 758                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
 759                         up(&dev->caw_sem);
 760                 }
 761                 complete_all(&cmd->t_transport_stop_comp);
 762                 return;
 763         } else if (!success) {
 764                 INIT_WORK(&cmd->work, target_complete_failure_work);
 765         } else {
 766                 INIT_WORK(&cmd->work, target_complete_ok_work);
 767         }
 768
 769         cmd->t_state = TRANSPORT_COMPLETE;
 770         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 771         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 772
 773         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 774                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 775         else
 776                 queue_work(target_completion_wq, &cmd->work);
 777 }
 778 EXPORT_SYMBOL(target_complete_cmd);
 779
 780 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 781 {
 782         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 783                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 784                         cmd->residual_count += cmd->data_length - length;
 785                 } else {
 786                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 787                         cmd->residual_count = cmd->data_length - length;
 788                 }
 789
 790                 cmd->data_length = length;
 791         }
 792
 793         target_complete_cmd(cmd, scsi_status);
 794 }
 795 EXPORT_SYMBOL(target_complete_cmd_with_length);
 796
 797 static void target_add_to_state_list(struct se_cmd *cmd)
 798 {
 799         struct se_device *dev = cmd->se_dev;
 800         unsigned long flags;
 801
 802         spin_lock_irqsave(&dev->execute_task_lock, flags);
 803         if (!cmd->state_active) {
 804                 list_add_tail(&cmd->state_list, &dev->state_list);
 805                 cmd->state_active = true;
 806         }
 807         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 808 }
 809
 810 /*
 811  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 812  */
 813 static void transport_write_pending_qf(struct se_cmd *cmd);
 814 static void transport_complete_qf(struct se_cmd *cmd);
 815
 816 void target_qf_do_work(struct work_struct *work)
 817 {
 818         struct se_device *dev = container_of(work, struct se_device,
 819                                         qf_work_queue);
 820         LIST_HEAD(qf_cmd_list);
 821         struct se_cmd *cmd, *cmd_tmp;
 822
 823         spin_lock_irq(&dev->qf_cmd_lock);
 824         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 825         spin_unlock_irq(&dev->qf_cmd_lock);
 826
 827         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 828                 list_del(&cmd->se_qf_node);
 829                 atomic_dec_mb(&dev->dev_qf_count);
 830
 831                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 832                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 833                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 834                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 835                         : "UNKNOWN");
 836
 837                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 838                         transport_write_pending_qf(cmd);
 839                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 840                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 841                         transport_complete_qf(cmd);
 842         }
 843 }
 844
 845 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 846 {
 847         switch (cmd->data_direction) {
 848         case DMA_NONE:
 849                 return "NONE";
 850         case DMA_FROM_DEVICE:
 851                 return "READ";
 852         case DMA_TO_DEVICE:
 853                 return "WRITE";
 854         case DMA_BIDIRECTIONAL:
 855                 return "BIDI";
 856         default:
 857                 break;
 858         }
 859
 860         return "UNKNOWN";
 861 }
 862
 863 void transport_dump_dev_state(
 864         struct se_device *dev,
 865         char *b,
 866         int *bl)
 867 {
 868         *bl += sprintf(b + *bl, "Status: ");
 869         if (dev->export_count)
 870                 *bl += sprintf(b + *bl, "ACTIVATED");
 871         else
 872                 *bl += sprintf(b + *bl, "DEACTIVATED");
 873
 874         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 875         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 876                 dev->dev_attrib.block_size,
 877                 dev->dev_attrib.hw_max_sectors);
 878         *bl += sprintf(b + *bl, "        ");
 879 }
 880
 881 void transport_dump_vpd_proto_id(
 882         struct t10_vpd *vpd,
 883         unsigned char *p_buf,
 884         int p_buf_len)
 885 {
 886         unsigned char buf[VPD_TMP_BUF_SIZE];
 887         int len;
 888
 889         memset(buf, 0, VPD_TMP_BUF_SIZE);
 890         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 891
 892         switch (vpd->protocol_identifier) {
 893         case 0x00:
 894                 sprintf(buf+len, "Fibre Channel\n");
 895                 break;
 896         case 0x10:
 897                 sprintf(buf+len, "Parallel SCSI\n");
 898                 break;
 899         case 0x20:
 900                 sprintf(buf+len, "SSA\n");
 901                 break;
 902         case 0x30:
 903                 sprintf(buf+len, "IEEE 1394\n");
 904                 break;
 905         case 0x40:
 906                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 907                                 " Protocol\n");
 908                 break;
 909         case 0x50:
 910                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 911                 break;
 912         case 0x60:
 913                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 914                 break;
 915         case 0x70:
 916                 sprintf(buf+len, "Automation/Drive Interface Transport"
 917                                 " Protocol\n");
 918                 break;
 919         case 0x80:
 920                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 921                 break;
 922         default:
 923                 sprintf(buf+len, "Unknown 0x%02x\n",
 924                                 vpd->protocol_identifier);
 925                 break;
 926         }
 927
 928         if (p_buf)
 929                 strncpy(p_buf, buf, p_buf_len);
 930         else
 931                 pr_debug("%s", buf);
 932 }
 933
 934 void
 935 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 936 {
 937         /*
 938          * Check if the Protocol Identifier Valid (PIV) bit is set..
 939          *
 940          * from spc3r23.pdf section 7.5.1
 941          */
 942          if (page_83[1] & 0x80) {
 943                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 944                 vpd->protocol_identifier_set = 1;
 945                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 946         }
 947 }
 948 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 949
 950 int transport_dump_vpd_assoc(
 951         struct t10_vpd *vpd,
 952         unsigned char *p_buf,
 953         int p_buf_len)
 954 {
 955         unsigned char buf[VPD_TMP_BUF_SIZE];
 956         int ret = 0;
 957         int len;
 958
 959         memset(buf, 0, VPD_TMP_BUF_SIZE);
 960         len = sprintf(buf, "T10 VPD Identifier Association: ");
 961
 962         switch (vpd->association) {
 963         case 0x00:
 964                 sprintf(buf+len, "addressed logical unit\n");
 965                 break;
 966         case 0x10:
 967                 sprintf(buf+len, "target port\n");
 968                 break;
 969         case 0x20:
 970                 sprintf(buf+len, "SCSI target device\n");
 971                 break;
 972         default:
 973                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 974                 ret = -EINVAL;
 975                 break;
 976         }
 977
 978         if (p_buf)
 979                 strncpy(p_buf, buf, p_buf_len);
 980         else
 981                 pr_debug("%s", buf);
 982
 983         return ret;
 984 }
 985
 986 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 987 {
 988         /*
 989          * The VPD identification association..
 990          *
 991          * from spc3r23.pdf Section 7.6.3.1 Table 297
 992          */
 993         vpd->association = (page_83[1] & 0x30);
 994         return transport_dump_vpd_assoc(vpd, NULL, 0);
 995 }
 996 EXPORT_SYMBOL(transport_set_vpd_assoc);
 997
 998 int transport_dump_vpd_ident_type(
 999         struct t10_vpd *vpd,
1000         unsigned char *p_buf,
1001         int p_buf_len)
1002 {
1003         unsigned char buf[VPD_TMP_BUF_SIZE];
1004         int ret = 0;
1005         int len;
1006
1007         memset(buf, 0, VPD_TMP_BUF_SIZE);
1008         len = sprintf(buf, "T10 VPD Identifier Type: ");
1009
1010         switch (vpd->device_identifier_type) {
1011         case 0x00:
1012                 sprintf(buf+len, "Vendor specific\n");
1013                 break;
1014         case 0x01:
1015                 sprintf(buf+len, "T10 Vendor ID based\n");
1016                 break;
1017         case 0x02:
1018                 sprintf(buf+len, "EUI-64 based\n");
1019                 break;
1020         case 0x03:
1021                 sprintf(buf+len, "NAA\n");
1022                 break;
1023         case 0x04:
1024                 sprintf(buf+len, "Relative target port identifier\n");
1025                 break;
1026         case 0x08:
1027                 sprintf(buf+len, "SCSI name string\n");
1028                 break;
1029         default:
1030                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1031                                 vpd->device_identifier_type);
1032                 ret = -EINVAL;
1033                 break;
1034         }
1035
1036         if (p_buf) {
1037                 if (p_buf_len < strlen(buf)+1)
1038                         return -EINVAL;
1039                 strncpy(p_buf, buf, p_buf_len);
1040         } else {
1041                 pr_debug("%s", buf);
1042         }
1043
1044         return ret;
1045 }
1046
1047 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1048 {
1049         /*
1050          * The VPD identifier type..
1051          *
1052          * from spc3r23.pdf Section 7.6.3.1 Table 298
1053          */
1054         vpd->device_identifier_type = (page_83[1] & 0x0f);
1055         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1056 }
1057 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1058
1059 int transport_dump_vpd_ident(
1060         struct t10_vpd *vpd,
1061         unsigned char *p_buf,
1062         int p_buf_len)
1063 {
1064         unsigned char buf[VPD_TMP_BUF_SIZE];
1065         int ret = 0;
1066
1067         memset(buf, 0, VPD_TMP_BUF_SIZE);
1068
1069         switch (vpd->device_identifier_code_set) {
1070         case 0x01: /* Binary */
1071                 snprintf(buf, sizeof(buf),
1072                         "T10 VPD Binary Device Identifier: %s\n",
1073                         &vpd->device_identifier[0]);
1074                 break;
1075         case 0x02: /* ASCII */
1076                 snprintf(buf, sizeof(buf),
1077                         "T10 VPD ASCII Device Identifier: %s\n",
1078                         &vpd->device_identifier[0]);
1079                 break;
1080         case 0x03: /* UTF-8 */
1081                 snprintf(buf, sizeof(buf),
1082                         "T10 VPD UTF-8 Device Identifier: %s\n",
1083                         &vpd->device_identifier[0]);
1084                 break;
1085         default:
1086                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1087                         " 0x%02x", vpd->device_identifier_code_set);
1088                 ret = -EINVAL;
1089                 break;
1090         }
1091
1092         if (p_buf)
1093                 strncpy(p_buf, buf, p_buf_len);
1094         else
1095                 pr_debug("%s", buf);
1096
1097         return ret;
1098 }
1099
1100 int
1101 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1102 {
1103         static const char hex_str[] = "0123456789abcdef";
1104         int j = 0, i = 4; /* offset to start of the identifier */
1105
1106         /*
1107          * The VPD Code Set (encoding)
1108          *
1109          * from spc3r23.pdf Section 7.6.3.1 Table 296
1110          */
1111         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1112         switch (vpd->device_identifier_code_set) {
1113         case 0x01: /* Binary */
1114                 vpd->device_identifier[j++] =
1115                                 hex_str[vpd->device_identifier_type];
1116                 while (i < (4 + page_83[3])) {
1117                         vpd->device_identifier[j++] =
1118                                 hex_str[(page_83[i] & 0xf0) >> 4];
1119                         vpd->device_identifier[j++] =
1120                                 hex_str[page_83[i] & 0x0f];
1121                         i++;
1122                 }
1123                 break;
1124         case 0x02: /* ASCII */
1125         case 0x03: /* UTF-8 */
1126                 while (i < (4 + page_83[3]))
1127                         vpd->device_identifier[j++] = page_83[i++];
1128                 break;
1129         default:
1130                 break;
1131         }
1132
1133         return transport_dump_vpd_ident(vpd, NULL, 0);
1134 }
1135 EXPORT_SYMBOL(transport_set_vpd_ident);
1136
1137 static sense_reason_t
1138 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1139                                unsigned int size)
1140 {
1141         u32 mtl;
1142
1143         if (!cmd->se_tfo->max_data_sg_nents)
1144                 return TCM_NO_SENSE;
1145         /*
1146          * Check if fabric enforced maximum SGL entries per I/O descriptor
1147          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1148          * residual_count and reduce original cmd->data_length to maximum
1149          * length based on single PAGE_SIZE entry scatter-lists.
1150          */
1151         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1152         if (cmd->data_length > mtl) {
1153                 /*
1154                  * If an existing CDB overflow is present, calculate new residual
1155                  * based on CDB size minus fabric maximum transfer length.
1156                  *
1157                  * If an existing CDB underflow is present, calculate new residual
1158                  * based on original cmd->data_length minus fabric maximum transfer
1159                  * length.
1160                  *
1161                  * Otherwise, set the underflow residual based on cmd->data_length
1162                  * minus fabric maximum transfer length.
1163                  */
1164                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1165                         cmd->residual_count = (size - mtl);
1166                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1167                         u32 orig_dl = size + cmd->residual_count;
1168                         cmd->residual_count = (orig_dl - mtl);
1169                 } else {
1170                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1171                         cmd->residual_count = (cmd->data_length - mtl);
1172                 }
1173                 cmd->data_length = mtl;
1174                 /*
1175                  * Reset sbc_check_prot() calculated protection payload
1176                  * length based upon the new smaller MTL.
1177                  */
1178                 if (cmd->prot_length) {
1179                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1180                         cmd->prot_length = dev->prot_length * sectors;
1181                 }
1182         }
1183         return TCM_NO_SENSE;
1184 }
1185
1186 sense_reason_t
1187 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1188 {
1189         struct se_device *dev = cmd->se_dev;
1190
1191         if (cmd->unknown_data_length) {
1192                 cmd->data_length = size;
1193         } else if (size != cmd->data_length) {
1194                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1195                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1196                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1197                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1198
1199                 if (cmd->data_direction == DMA_TO_DEVICE) {
1200                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1201                                 pr_err_ratelimited("Rejecting underflow/overflow"
1202                                                    " for WRITE data CDB\n");
1203                                 return TCM_INVALID_CDB_FIELD;
1204                         }
1205                         /*
1206                          * Some fabric drivers like iscsi-target still expect to
1207                          * always reject overflow writes.  Reject this case until
1208                          * full fabric driver level support for overflow writes
1209                          * is introduced tree-wide.
1210                          */
1211                         if (size > cmd->data_length) {
1212                                 pr_err_ratelimited("Rejecting overflow for"
1213                                                    " WRITE control CDB\n");
1214                                 return TCM_INVALID_CDB_FIELD;
1215                         }
1216                 }
1217                 /*
1218                  * Reject READ_* or WRITE_* with overflow/underflow for
1219                  * type SCF_SCSI_DATA_CDB.
1220                  */
1221                 if (dev->dev_attrib.block_size != 512)  {
1222                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1223                                 " CDB on non 512-byte sector setup subsystem"
1224                                 " plugin: %s\n", dev->transport->name);
1225                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1226                         return TCM_INVALID_CDB_FIELD;
1227                 }
1228                 /*
1229                  * For the overflow case keep the existing fabric provided
1230                  * ->data_length.  Otherwise for the underflow case, reset
1231                  * ->data_length to the smaller SCSI expected data transfer
1232                  * length.
1233                  */
1234                 if (size > cmd->data_length) {
1235                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1236                         cmd->residual_count = (size - cmd->data_length);
1237                 } else {
1238                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1239                         cmd->residual_count = (cmd->data_length - size);
1240                         cmd->data_length = size;
1241                 }
1242         }
1243
1244         return target_check_max_data_sg_nents(cmd, dev, size);
1245
1246 }
1247
1248 /*
1249  * Used by fabric modules containing a local struct se_cmd within their
1250  * fabric dependent per I/O descriptor.
1251  *
1252  * Preserves the value of @cmd->tag.
1253  */
1254 void transport_init_se_cmd(
1255         struct se_cmd *cmd,
1256         const struct target_core_fabric_ops *tfo,
1257         struct se_session *se_sess,
1258         u32 data_length,
1259         int data_direction,
1260         int task_attr,
1261         unsigned char *sense_buffer)
1262 {
1263         INIT_LIST_HEAD(&cmd->se_delayed_node);
1264         INIT_LIST_HEAD(&cmd->se_qf_node);
1265         INIT_LIST_HEAD(&cmd->se_cmd_list);
1266         INIT_LIST_HEAD(&cmd->state_list);
1267         init_completion(&cmd->t_transport_stop_comp);
1268         init_completion(&cmd->cmd_wait_comp);
1269         spin_lock_init(&cmd->t_state_lock);
1270         INIT_WORK(&cmd->work, NULL);
1271         kref_init(&cmd->cmd_kref);
1272
1273         cmd->se_tfo = tfo;
1274         cmd->se_sess = se_sess;
1275         cmd->data_length = data_length;
1276         cmd->data_direction = data_direction;
1277         cmd->sam_task_attr = task_attr;
1278         cmd->sense_buffer = sense_buffer;
1279
1280         cmd->state_active = false;
1281 }
1282 EXPORT_SYMBOL(transport_init_se_cmd);
1283
1284 static sense_reason_t
1285 transport_check_alloc_task_attr(struct se_cmd *cmd)
1286 {
1287         struct se_device *dev = cmd->se_dev;
1288
1289         /*
1290          * Check if SAM Task Attribute emulation is enabled for this
1291          * struct se_device storage object
1292          */
1293         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1294                 return 0;
1295
1296         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1297                 pr_debug("SAM Task Attribute ACA"
1298                         " emulation is not supported\n");
1299                 return TCM_INVALID_CDB_FIELD;
1300         }
1301
1302         return 0;
1303 }
1304
1305 sense_reason_t
1306 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1307 {
1308         struct se_device *dev = cmd->se_dev;
1309         sense_reason_t ret;
1310
1311         /*
1312          * Ensure that the received CDB is less than the max (252 + 8) bytes
1313          * for VARIABLE_LENGTH_CMD
1314          */
1315         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1316                 pr_err("Received SCSI CDB with command_size: %d that"
1317                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1318                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1319                 return TCM_INVALID_CDB_FIELD;
1320         }
1321         /*
1322          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1323          * allocate the additional extended CDB buffer now..  Otherwise
1324          * setup the pointer from __t_task_cdb to t_task_cdb.
1325          */
1326         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1327                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1328                                                 GFP_KERNEL);
1329                 if (!cmd->t_task_cdb) {
1330                         pr_err("Unable to allocate cmd->t_task_cdb"
1331                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1332                                 scsi_command_size(cdb),
1333                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1334                         return TCM_OUT_OF_RESOURCES;
1335                 }
1336         } else
1337                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1338         /*
1339          * Copy the original CDB into cmd->
1340          */
1341         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1342
1343         trace_target_sequencer_start(cmd);
1344
1345         ret = dev->transport->parse_cdb(cmd);
1346         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1347                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1348                                     cmd->se_tfo->get_fabric_name(),
1349                                     cmd->se_sess->se_node_acl->initiatorname,
1350                                     cmd->t_task_cdb[0]);
1351         if (ret)
1352                 return ret;
1353
1354         ret = transport_check_alloc_task_attr(cmd);
1355         if (ret)
1356                 return ret;
1357
1358         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1359         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1360         return 0;
1361 }
1362 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1363
1364 /*
1365  * Used by fabric module frontends to queue tasks directly.
1366  * May only be used from process context.
1367  */
1368 int transport_handle_cdb_direct(
1369         struct se_cmd *cmd)
1370 {
1371         sense_reason_t ret;
1372
1373         if (!cmd->se_lun) {
1374                 dump_stack();
1375                 pr_err("cmd->se_lun is NULL\n");
1376                 return -EINVAL;
1377         }
1378         if (in_interrupt()) {
1379                 dump_stack();
1380                 pr_err("transport_generic_handle_cdb cannot be called"
1381                                 " from interrupt context\n");
1382                 return -EINVAL;
1383         }
1384         /*
1385          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1386          * outstanding descriptors are handled correctly during shutdown via
1387          * transport_wait_for_tasks()
1388          *
1389          * Also, we don't take cmd->t_state_lock here as we only expect
1390          * this to be called for initial descriptor submission.
1391          */
1392         cmd->t_state = TRANSPORT_NEW_CMD;
1393         cmd->transport_state |= CMD_T_ACTIVE;
1394
1395         /*
1396          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1397          * so follow TRANSPORT_NEW_CMD processing thread context usage
1398          * and call transport_generic_request_failure() if necessary..
1399          */
1400         ret = transport_generic_new_cmd(cmd);
1401         if (ret)
1402                 transport_generic_request_failure(cmd, ret);
1403         return 0;
1404 }
1405 EXPORT_SYMBOL(transport_handle_cdb_direct);
1406
1407 sense_reason_t
1408 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1409                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1410 {
1411         if (!sgl || !sgl_count)
1412                 return 0;
1413
1414         /*
1415          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1416          * scatterlists already have been set to follow what the fabric
1417          * passes for the original expected data transfer length.
1418          */
1419         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1420                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1421                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1422                 return TCM_INVALID_CDB_FIELD;
1423         }
1424
1425         cmd->t_data_sg = sgl;
1426         cmd->t_data_nents = sgl_count;
1427         cmd->t_bidi_data_sg = sgl_bidi;
1428         cmd->t_bidi_data_nents = sgl_bidi_count;
1429
1430         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1431         return 0;
1432 }
1433
1434 /*
1435  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1436  *                       se_cmd + use pre-allocated SGL memory.
1437  *
1438  * @se_cmd: command descriptor to submit
1439  * @se_sess: associated se_sess for endpoint
1440  * @cdb: pointer to SCSI CDB
1441  * @sense: pointer to SCSI sense buffer
1442  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1443  * @data_length: fabric expected data transfer length
1444  * @task_addr: SAM task attribute
1445  * @data_dir: DMA data direction
1446  * @flags: flags for command submission from target_sc_flags_tables
1447  * @sgl: struct scatterlist memory for unidirectional mapping
1448  * @sgl_count: scatterlist count for unidirectional mapping
1449  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1450  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1451  * @sgl_prot: struct scatterlist memory protection information
1452  * @sgl_prot_count: scatterlist count for protection information
1453  *
1454  * Task tags are supported if the caller has set @se_cmd->tag.
1455  *
1456  * Returns non zero to signal active I/O shutdown failure.  All other
1457  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1458  * but still return zero here.
1459  *
1460  * This may only be called from process context, and also currently
1461  * assumes internal allocation of fabric payload buffer by target-core.
1462  */
1463 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1464                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1465                 u32 data_length, int task_attr, int data_dir, int flags,
1466                 struct scatterlist *sgl, u32 sgl_count,
1467                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1468                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1469 {
1470         struct se_portal_group *se_tpg;
1471         sense_reason_t rc;
1472         int ret;
1473
1474         se_tpg = se_sess->se_tpg;
1475         BUG_ON(!se_tpg);
1476         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1477         BUG_ON(in_interrupt());
1478         /*
1479          * Initialize se_cmd for target operation.  From this point
1480          * exceptions are handled by sending exception status via
1481          * target_core_fabric_ops->queue_status() callback
1482          */
1483         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1484                                 data_length, data_dir, task_attr, sense);
1485
1486         if (flags & TARGET_SCF_USE_CPUID)
1487                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1488         else
1489                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1490
1491         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1492                 se_cmd->unknown_data_length = 1;
1493         /*
1494          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1495          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1496          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1497          * kref_put() to happen during fabric packet acknowledgement.
1498          */
1499         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1500         if (ret)
1501                 return ret;
1502         /*
1503          * Signal bidirectional data payloads to target-core
1504          */
1505         if (flags & TARGET_SCF_BIDI_OP)
1506                 se_cmd->se_cmd_flags |= SCF_BIDI;
1507         /*
1508          * Locate se_lun pointer and attach it to struct se_cmd
1509          */
1510         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1511         if (rc) {
1512                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1513                 target_put_sess_cmd(se_cmd);
1514                 return 0;
1515         }
1516
1517         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1518         if (rc != 0) {
1519                 transport_generic_request_failure(se_cmd, rc);
1520                 return 0;
1521         }
1522
1523         /*
1524          * Save pointers for SGLs containing protection information,
1525          * if present.
1526          */
1527         if (sgl_prot_count) {
1528                 se_cmd->t_prot_sg = sgl_prot;
1529                 se_cmd->t_prot_nents = sgl_prot_count;
1530                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1531         }
1532
1533         /*
1534          * When a non zero sgl_count has been passed perform SGL passthrough
1535          * mapping for pre-allocated fabric memory instead of having target
1536          * core perform an internal SGL allocation..
1537          */
1538         if (sgl_count != 0) {
1539                 BUG_ON(!sgl);
1540
1541                 /*
1542                  * A work-around for tcm_loop as some userspace code via
1543                  * scsi-generic do not memset their associated read buffers,
1544                  * so go ahead and do that here for type non-data CDBs.  Also
1545                  * note that this is currently guaranteed to be a single SGL
1546                  * for this case by target core in target_setup_cmd_from_cdb()
1547                  * -> transport_generic_cmd_sequencer().
1548                  */
1549                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1550                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1551                         unsigned char *buf = NULL;
1552
1553                         if (sgl)
1554                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1555
1556                         if (buf) {
1557                                 memset(buf, 0, sgl->length);
1558                                 kunmap(sg_page(sgl));
1559                         }
1560                 }
1561
1562                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1563                                 sgl_bidi, sgl_bidi_count);
1564                 if (rc != 0) {
1565                         transport_generic_request_failure(se_cmd, rc);
1566                         return 0;
1567                 }
1568         }
1569
1570         /*
1571          * Check if we need to delay processing because of ALUA
1572          * Active/NonOptimized primary access state..
1573          */
1574         core_alua_check_nonop_delay(se_cmd);
1575
1576         transport_handle_cdb_direct(se_cmd);
1577         return 0;
1578 }
1579 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1580
1581 /*
1582  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1583  *
1584  * @se_cmd: command descriptor to submit
1585  * @se_sess: associated se_sess for endpoint
1586  * @cdb: pointer to SCSI CDB
1587  * @sense: pointer to SCSI sense buffer
1588  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1589  * @data_length: fabric expected data transfer length
1590  * @task_addr: SAM task attribute
1591  * @data_dir: DMA data direction
1592  * @flags: flags for command submission from target_sc_flags_tables
1593  *
1594  * Task tags are supported if the caller has set @se_cmd->tag.
1595  *
1596  * Returns non zero to signal active I/O shutdown failure.  All other
1597  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1598  * but still return zero here.
1599  *
1600  * This may only be called from process context, and also currently
1601  * assumes internal allocation of fabric payload buffer by target-core.
1602  *
1603  * It also assumes interal target core SGL memory allocation.
1604  */
1605 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1606                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1607                 u32 data_length, int task_attr, int data_dir, int flags)
1608 {
1609         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1610                         unpacked_lun, data_length, task_attr, data_dir,
1611                         flags, NULL, 0, NULL, 0, NULL, 0);
1612 }
1613 EXPORT_SYMBOL(target_submit_cmd);
1614
1615 static void target_complete_tmr_failure(struct work_struct *work)
1616 {
1617         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1618
1619         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1620         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1621
1622         transport_lun_remove_cmd(se_cmd);
1623         transport_cmd_check_stop_to_fabric(se_cmd);
1624 }
1625
1626 static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
1627                                        u64 *unpacked_lun)
1628 {
1629         struct se_cmd *se_cmd;
1630         unsigned long flags;
1631         bool ret = false;
1632
1633         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
1634         list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
1635                 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1636                         continue;
1637
1638                 if (se_cmd->tag == tag) {
1639                         *unpacked_lun = se_cmd->orig_fe_lun;
1640                         ret = true;
1641                         break;
1642                 }
1643         }
1644         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
1645
1646         return ret;
1647 }
1648
1649 /**
1650  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1651  *                     for TMR CDBs
1652  *
1653  * @se_cmd: command descriptor to submit
1654  * @se_sess: associated se_sess for endpoint
1655  * @sense: pointer to SCSI sense buffer
1656  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1657  * @fabric_context: fabric context for TMR req
1658  * @tm_type: Type of TM request
1659  * @gfp: gfp type for caller
1660  * @tag: referenced task tag for TMR_ABORT_TASK
1661  * @flags: submit cmd flags
1662  *
1663  * Callable from all contexts.
1664  **/
1665
1666 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1667                 unsigned char *sense, u64 unpacked_lun,
1668                 void *fabric_tmr_ptr, unsigned char tm_type,
1669                 gfp_t gfp, u64 tag, int flags)
1670 {
1671         struct se_portal_group *se_tpg;
1672         int ret;
1673
1674         se_tpg = se_sess->se_tpg;
1675         BUG_ON(!se_tpg);
1676
1677         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1678                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1679         /*
1680          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1681          * allocation failure.
1682          */
1683         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1684         if (ret < 0)
1685                 return -ENOMEM;
1686
1687         if (tm_type == TMR_ABORT_TASK)
1688                 se_cmd->se_tmr_req->ref_task_tag = tag;
1689
1690         /* See target_submit_cmd for commentary */
1691         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1692         if (ret) {
1693                 core_tmr_release_req(se_cmd->se_tmr_req);
1694                 return ret;
1695         }
1696         /*
1697          * If this is ABORT_TASK with no explicit fabric provided LUN,
1698          * go ahead and search active session tags for a match to figure
1699          * out unpacked_lun for the original se_cmd.
1700          */
1701         if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
1702                 if (!target_lookup_lun_from_tag(se_sess, tag, &unpacked_lun))
1703                         goto failure;
1704         }
1705
1706         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1707         if (ret)
1708                 goto failure;
1709
1710         transport_generic_handle_tmr(se_cmd);
1711         return 0;
1712
1713         /*
1714          * For callback during failure handling, push this work off
1715          * to process context with TMR_LUN_DOES_NOT_EXIST status.
1716          */
1717 failure:
1718         INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1719         schedule_work(&se_cmd->work);
1720         return 0;
1721 }
1722 EXPORT_SYMBOL(target_submit_tmr);
1723
1724 /*
1725  * Handle SAM-esque emulation for generic transport request failures.
1726  */
1727 void transport_generic_request_failure(struct se_cmd *cmd,
1728                 sense_reason_t sense_reason)
1729 {
1730         int ret = 0, post_ret = 0;
1731
1732         pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
1733                  sense_reason);
1734         target_show_cmd("-----[ ", cmd);
1735
1736         /*
1737          * For SAM Task Attribute emulation for failed struct se_cmd
1738          */
1739         transport_complete_task_attr(cmd);
1740
1741         /*
1742          * Handle special case for COMPARE_AND_WRITE failure, where the
1743          * callback is expected to drop the per device ->caw_sem.
1744          */
1745         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1746              cmd->transport_complete_callback)
1747                 cmd->transport_complete_callback(cmd, false, &post_ret);
1748
1749         if (transport_check_aborted_status(cmd, 1))
1750                 return;
1751
1752         switch (sense_reason) {
1753         case TCM_NON_EXISTENT_LUN:
1754         case TCM_UNSUPPORTED_SCSI_OPCODE:
1755         case TCM_INVALID_CDB_FIELD:
1756         case TCM_INVALID_PARAMETER_LIST:
1757         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1758         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1759         case TCM_UNKNOWN_MODE_PAGE:
1760         case TCM_WRITE_PROTECTED:
1761         case TCM_ADDRESS_OUT_OF_RANGE:
1762         case TCM_CHECK_CONDITION_ABORT_CMD:
1763         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1764         case TCM_CHECK_CONDITION_NOT_READY:
1765         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1766         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1767         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1768         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1769         case TCM_TOO_MANY_TARGET_DESCS:
1770         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1771         case TCM_TOO_MANY_SEGMENT_DESCS:
1772         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1773                 break;
1774         case TCM_OUT_OF_RESOURCES:
1775                 cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
1776                 goto queue_status;
1777         case TCM_LUN_BUSY:
1778                 cmd->scsi_status = SAM_STAT_BUSY;
1779                 goto queue_status;
1780         case TCM_RESERVATION_CONFLICT:
1781                 /*
1782                  * No SENSE Data payload for this case, set SCSI Status
1783                  * and queue the response to $FABRIC_MOD.
1784                  *
1785                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1786                  */
1787                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1788                 /*
1789                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1790                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1791                  * CONFLICT STATUS.
1792                  *
1793                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1794                  */
1795                 if (cmd->se_sess &&
1796                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1797                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1798                                                cmd->orig_fe_lun, 0x2C,
1799                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1800                 }
1801
1802                 goto queue_status;
1803         default:
1804                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1805                         cmd->t_task_cdb[0], sense_reason);
1806                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1807                 break;
1808         }
1809
1810         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1811         if (ret)
1812                 goto queue_full;
1813
1814 check_stop:
1815         transport_lun_remove_cmd(cmd);
1816         transport_cmd_check_stop_to_fabric(cmd);
1817         return;
1818
1819 queue_status:
1820         trace_target_cmd_complete(cmd);
1821         ret = cmd->se_tfo->queue_status(cmd);
1822         if (!ret)
1823                 goto check_stop;
1824 queue_full:
1825         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1826 }
1827 EXPORT_SYMBOL(transport_generic_request_failure);
1828
1829 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1830 {
1831         sense_reason_t ret;
1832
1833         if (!cmd->execute_cmd) {
1834                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1835                 goto err;
1836         }
1837         if (do_checks) {
1838                 /*
1839                  * Check for an existing UNIT ATTENTION condition after
1840                  * target_handle_task_attr() has done SAM task attr
1841                  * checking, and possibly have already defered execution
1842                  * out to target_restart_delayed_cmds() context.
1843                  */
1844                 ret = target_scsi3_ua_check(cmd);
1845                 if (ret)
1846                         goto err;
1847
1848                 ret = target_alua_state_check(cmd);
1849                 if (ret)
1850                         goto err;
1851
1852                 ret = target_check_reservation(cmd);
1853                 if (ret) {
1854                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1855                         goto err;
1856                 }
1857         }
1858
1859         ret = cmd->execute_cmd(cmd);
1860         if (!ret)
1861                 return;
1862 err:
1863         spin_lock_irq(&cmd->t_state_lock);
1864         cmd->transport_state &= ~CMD_T_SENT;
1865         spin_unlock_irq(&cmd->t_state_lock);
1866
1867         transport_generic_request_failure(cmd, ret);
1868 }
1869
1870 static int target_write_prot_action(struct se_cmd *cmd)
1871 {
1872         u32 sectors;
1873         /*
1874          * Perform WRITE_INSERT of PI using software emulation when backend
1875          * device has PI enabled, if the transport has not already generated
1876          * PI using hardware WRITE_INSERT offload.
1877          */
1878         switch (cmd->prot_op) {
1879         case TARGET_PROT_DOUT_INSERT:
1880                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1881                         sbc_dif_generate(cmd);
1882                 break;
1883         case TARGET_PROT_DOUT_STRIP:
1884                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1885                         break;
1886
1887                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1888                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1889                                              sectors, 0, cmd->t_prot_sg, 0);
1890                 if (unlikely(cmd->pi_err)) {
1891                         spin_lock_irq(&cmd->t_state_lock);
1892                         cmd->transport_state &= ~CMD_T_SENT;
1893                         spin_unlock_irq(&cmd->t_state_lock);
1894                         transport_generic_request_failure(cmd, cmd->pi_err);
1895                         return -1;
1896                 }
1897                 break;
1898         default:
1899                 break;
1900         }
1901
1902         return 0;
1903 }
1904
1905 static bool target_handle_task_attr(struct se_cmd *cmd)
1906 {
1907         struct se_device *dev = cmd->se_dev;
1908
1909         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1910                 return false;
1911
1912         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1913
1914         /*
1915          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1916          * to allow the passed struct se_cmd list of tasks to the front of the list.
1917          */
1918         switch (cmd->sam_task_attr) {
1919         case TCM_HEAD_TAG:
1920                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1921                          cmd->t_task_cdb[0]);
1922                 return false;
1923         case TCM_ORDERED_TAG:
1924                 atomic_inc_mb(&dev->dev_ordered_sync);
1925
1926                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1927                          cmd->t_task_cdb[0]);
1928
1929                 /*
1930                  * Execute an ORDERED command if no other older commands
1931                  * exist that need to be completed first.
1932                  */
1933                 if (!atomic_read(&dev->simple_cmds))
1934                         return false;
1935                 break;
1936         default:
1937                 /*
1938                  * For SIMPLE and UNTAGGED Task Attribute commands
1939                  */
1940                 atomic_inc_mb(&dev->simple_cmds);
1941                 break;
1942         }
1943
1944         if (atomic_read(&dev->dev_ordered_sync) == 0)
1945                 return false;
1946
1947         spin_lock(&dev->delayed_cmd_lock);
1948         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1949         spin_unlock(&dev->delayed_cmd_lock);
1950
1951         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1952                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1953         return true;
1954 }
1955
1956 static int __transport_check_aborted_status(struct se_cmd *, int);
1957
1958 void target_execute_cmd(struct se_cmd *cmd)
1959 {
1960         /*
1961          * Determine if frontend context caller is requesting the stopping of
1962          * this command for frontend exceptions.
1963          *
1964          * If the received CDB has aleady been aborted stop processing it here.
1965          */
1966         spin_lock_irq(&cmd->t_state_lock);
1967         if (__transport_check_aborted_status(cmd, 1)) {
1968                 spin_unlock_irq(&cmd->t_state_lock);
1969                 return;
1970         }
1971         if (cmd->transport_state & CMD_T_STOP) {
1972                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1973                         __func__, __LINE__, cmd->tag);
1974
1975                 spin_unlock_irq(&cmd->t_state_lock);
1976                 complete_all(&cmd->t_transport_stop_comp);
1977                 return;
1978         }
1979
1980         cmd->t_state = TRANSPORT_PROCESSING;
1981         cmd->transport_state &= ~CMD_T_PRE_EXECUTE;
1982         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
1983         spin_unlock_irq(&cmd->t_state_lock);
1984
1985         if (target_write_prot_action(cmd))
1986                 return;
1987
1988         if (target_handle_task_attr(cmd)) {
1989                 spin_lock_irq(&cmd->t_state_lock);
1990                 cmd->transport_state &= ~CMD_T_SENT;
1991                 spin_unlock_irq(&cmd->t_state_lock);
1992                 return;
1993         }
1994
1995         __target_execute_cmd(cmd, true);
1996 }
1997 EXPORT_SYMBOL(target_execute_cmd);
1998
1999 /*
2000  * Process all commands up to the last received ORDERED task attribute which
2001  * requires another blocking boundary
2002  */
2003 static void target_restart_delayed_cmds(struct se_device *dev)
2004 {
2005         for (;;) {
2006                 struct se_cmd *cmd;
2007
2008                 spin_lock(&dev->delayed_cmd_lock);
2009                 if (list_empty(&dev->delayed_cmd_list)) {
2010                         spin_unlock(&dev->delayed_cmd_lock);
2011                         break;
2012                 }
2013
2014                 cmd = list_entry(dev->delayed_cmd_list.next,
2015                                  struct se_cmd, se_delayed_node);
2016                 list_del(&cmd->se_delayed_node);
2017                 spin_unlock(&dev->delayed_cmd_lock);
2018
2019                 cmd->transport_state |= CMD_T_SENT;
2020
2021                 __target_execute_cmd(cmd, true);
2022
2023                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
2024                         break;
2025         }
2026 }
2027
2028 /*
2029  * Called from I/O completion to determine which dormant/delayed
2030  * and ordered cmds need to have their tasks added to the execution queue.
2031  */
2032 static void transport_complete_task_attr(struct se_cmd *cmd)
2033 {
2034         struct se_device *dev = cmd->se_dev;
2035
2036         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2037                 return;
2038
2039         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2040                 goto restart;
2041
2042         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2043                 atomic_dec_mb(&dev->simple_cmds);
2044                 dev->dev_cur_ordered_id++;
2045         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2046                 dev->dev_cur_ordered_id++;
2047                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2048                          dev->dev_cur_ordered_id);
2049         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2050                 atomic_dec_mb(&dev->dev_ordered_sync);
2051
2052                 dev->dev_cur_ordered_id++;
2053                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2054                          dev->dev_cur_ordered_id);
2055         }
2056         cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2057
2058 restart:
2059         target_restart_delayed_cmds(dev);
2060 }
2061
2062 static void transport_complete_qf(struct se_cmd *cmd)
2063 {
2064         int ret = 0;
2065
2066         transport_complete_task_attr(cmd);
2067         /*
2068          * If a fabric driver ->write_pending() or ->queue_data_in() callback
2069          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2070          * the same callbacks should not be retried.  Return CHECK_CONDITION
2071          * if a scsi_status is not already set.
2072          *
2073          * If a fabric driver ->queue_status() has returned non zero, always
2074          * keep retrying no matter what..
2075          */
2076         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2077                 if (cmd->scsi_status)
2078                         goto queue_status;
2079
2080                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2081                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2082                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2083                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2084                 goto queue_status;
2085         }
2086
2087         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2088                 goto queue_status;
2089
2090         switch (cmd->data_direction) {
2091         case DMA_FROM_DEVICE:
2092                 if (cmd->scsi_status)
2093                         goto queue_status;
2094
2095                 trace_target_cmd_complete(cmd);
2096                 ret = cmd->se_tfo->queue_data_in(cmd);
2097                 break;
2098         case DMA_TO_DEVICE:
2099                 if (cmd->se_cmd_flags & SCF_BIDI) {
2100                         ret = cmd->se_tfo->queue_data_in(cmd);
2101                         break;
2102                 }
2103                 /* fall through */
2104         case DMA_NONE:
2105 queue_status:
2106                 trace_target_cmd_complete(cmd);
2107                 ret = cmd->se_tfo->queue_status(cmd);
2108                 break;
2109         default:
2110                 break;
2111         }
2112
2113         if (ret < 0) {
2114                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2115                 return;
2116         }
2117         transport_lun_remove_cmd(cmd);
2118         transport_cmd_check_stop_to_fabric(cmd);
2119 }
2120
2121 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2122                                         int err, bool write_pending)
2123 {
2124         /*
2125          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2126          * ->queue_data_in() callbacks from new process context.
2127          *
2128          * Otherwise for other errors, transport_complete_qf() will send
2129          * CHECK_CONDITION via ->queue_status() instead of attempting to
2130          * retry associated fabric driver data-transfer callbacks.
2131          */
2132         if (err == -EAGAIN || err == -ENOMEM) {
2133                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2134                                                  TRANSPORT_COMPLETE_QF_OK;
2135         } else {
2136                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2137                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2138         }
2139
2140         spin_lock_irq(&dev->qf_cmd_lock);
2141         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2142         atomic_inc_mb(&dev->dev_qf_count);
2143         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2144
2145         schedule_work(&cmd->se_dev->qf_work_queue);
2146 }
2147
2148 static bool target_read_prot_action(struct se_cmd *cmd)
2149 {
2150         switch (cmd->prot_op) {
2151         case TARGET_PROT_DIN_STRIP:
2152                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2153                         u32 sectors = cmd->data_length >>
2154                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2155
2156                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2157                                                      sectors, 0, cmd->t_prot_sg,
2158                                                      0);
2159                         if (cmd->pi_err)
2160                                 return true;
2161                 }
2162                 break;
2163         case TARGET_PROT_DIN_INSERT:
2164                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2165                         break;
2166
2167                 sbc_dif_generate(cmd);
2168                 break;
2169         default:
2170                 break;
2171         }
2172
2173         return false;
2174 }
2175
2176 static void target_complete_ok_work(struct work_struct *work)
2177 {
2178         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2179         int ret;
2180
2181         /*
2182          * Check if we need to move delayed/dormant tasks from cmds on the
2183          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2184          * Attribute.
2185          */
2186         transport_complete_task_attr(cmd);
2187
2188         /*
2189          * Check to schedule QUEUE_FULL work, or execute an existing
2190          * cmd->transport_qf_callback()
2191          */
2192         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2193                 schedule_work(&cmd->se_dev->qf_work_queue);
2194
2195         /*
2196          * Check if we need to send a sense buffer from
2197          * the struct se_cmd in question.
2198          */
2199         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2200                 WARN_ON(!cmd->scsi_status);
2201                 ret = transport_send_check_condition_and_sense(
2202                                         cmd, 0, 1);
2203                 if (ret)
2204                         goto queue_full;
2205
2206                 transport_lun_remove_cmd(cmd);
2207                 transport_cmd_check_stop_to_fabric(cmd);
2208                 return;
2209         }
2210         /*
2211          * Check for a callback, used by amongst other things
2212          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2213          */
2214         if (cmd->transport_complete_callback) {
2215                 sense_reason_t rc;
2216                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2217                 bool zero_dl = !(cmd->data_length);
2218                 int post_ret = 0;
2219
2220                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2221                 if (!rc && !post_ret) {
2222                         if (caw && zero_dl)
2223                                 goto queue_rsp;
2224
2225                         return;
2226                 } else if (rc) {
2227                         ret = transport_send_check_condition_and_sense(cmd,
2228                                                 rc, 0);
2229                         if (ret)
2230                                 goto queue_full;
2231
2232                         transport_lun_remove_cmd(cmd);
2233                         transport_cmd_check_stop_to_fabric(cmd);
2234                         return;
2235                 }
2236         }
2237
2238 queue_rsp:
2239         switch (cmd->data_direction) {
2240         case DMA_FROM_DEVICE:
2241                 if (cmd->scsi_status)
2242                         goto queue_status;
2243
2244                 atomic_long_add(cmd->data_length,
2245                                 &cmd->se_lun->lun_stats.tx_data_octets);
2246                 /*
2247                  * Perform READ_STRIP of PI using software emulation when
2248                  * backend had PI enabled, if the transport will not be
2249                  * performing hardware READ_STRIP offload.
2250                  */
2251                 if (target_read_prot_action(cmd)) {
2252                         ret = transport_send_check_condition_and_sense(cmd,
2253                                                 cmd->pi_err, 0);
2254                         if (ret)
2255                                 goto queue_full;
2256
2257                         transport_lun_remove_cmd(cmd);
2258                         transport_cmd_check_stop_to_fabric(cmd);
2259                         return;
2260                 }
2261
2262                 trace_target_cmd_complete(cmd);
2263                 ret = cmd->se_tfo->queue_data_in(cmd);
2264                 if (ret)
2265                         goto queue_full;
2266                 break;
2267         case DMA_TO_DEVICE:
2268                 atomic_long_add(cmd->data_length,
2269                                 &cmd->se_lun->lun_stats.rx_data_octets);
2270                 /*
2271                  * Check if we need to send READ payload for BIDI-COMMAND
2272                  */
2273                 if (cmd->se_cmd_flags & SCF_BIDI) {
2274                         atomic_long_add(cmd->data_length,
2275                                         &cmd->se_lun->lun_stats.tx_data_octets);
2276                         ret = cmd->se_tfo->queue_data_in(cmd);
2277                         if (ret)
2278                                 goto queue_full;
2279                         break;
2280                 }
2281                 /* fall through */
2282         case DMA_NONE:
2283 queue_status:
2284                 trace_target_cmd_complete(cmd);
2285                 ret = cmd->se_tfo->queue_status(cmd);
2286                 if (ret)
2287                         goto queue_full;
2288                 break;
2289         default:
2290                 break;
2291         }
2292
2293         transport_lun_remove_cmd(cmd);
2294         transport_cmd_check_stop_to_fabric(cmd);
2295         return;
2296
2297 queue_full:
2298         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2299                 " data_direction: %d\n", cmd, cmd->data_direction);
2300
2301         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2302 }
2303
2304 void target_free_sgl(struct scatterlist *sgl, int nents)
2305 {
2306         struct scatterlist *sg;
2307         int count;
2308
2309         for_each_sg(sgl, sg, nents, count)
2310                 __free_page(sg_page(sg));
2311
2312         kfree(sgl);
2313 }
2314 EXPORT_SYMBOL(target_free_sgl);
2315
2316 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2317 {
2318         /*
2319          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2320          * emulation, and free + reset pointers if necessary..
2321          */
2322         if (!cmd->t_data_sg_orig)
2323                 return;
2324
2325         kfree(cmd->t_data_sg);
2326         cmd->t_data_sg = cmd->t_data_sg_orig;
2327         cmd->t_data_sg_orig = NULL;
2328         cmd->t_data_nents = cmd->t_data_nents_orig;
2329         cmd->t_data_nents_orig = 0;
2330 }
2331
2332 static inline void transport_free_pages(struct se_cmd *cmd)
2333 {
2334         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2335                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2336                 cmd->t_prot_sg = NULL;
2337                 cmd->t_prot_nents = 0;
2338         }
2339
2340         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2341                 /*
2342                  * Release special case READ buffer payload required for
2343                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2344                  */
2345                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2346                         target_free_sgl(cmd->t_bidi_data_sg,
2347                                            cmd->t_bidi_data_nents);
2348                         cmd->t_bidi_data_sg = NULL;
2349                         cmd->t_bidi_data_nents = 0;
2350                 }
2351                 transport_reset_sgl_orig(cmd);
2352                 return;
2353         }
2354         transport_reset_sgl_orig(cmd);
2355
2356         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2357         cmd->t_data_sg = NULL;
2358         cmd->t_data_nents = 0;
2359
2360         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2361         cmd->t_bidi_data_sg = NULL;
2362         cmd->t_bidi_data_nents = 0;
2363 }
2364
2365 void *transport_kmap_data_sg(struct se_cmd *cmd)
2366 {
2367         struct scatterlist *sg = cmd->t_data_sg;
2368         struct page **pages;
2369         int i;
2370
2371         /*
2372          * We need to take into account a possible offset here for fabrics like
2373          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2374          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2375          */
2376         if (!cmd->t_data_nents)
2377                 return NULL;
2378
2379         BUG_ON(!sg);
2380         if (cmd->t_data_nents == 1)
2381                 return kmap(sg_page(sg)) + sg->offset;
2382
2383         /* >1 page. use vmap */
2384         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2385         if (!pages)
2386                 return NULL;
2387
2388         /* convert sg[] to pages[] */
2389         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2390                 pages[i] = sg_page(sg);
2391         }
2392
2393         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2394         kfree(pages);
2395         if (!cmd->t_data_vmap)
2396                 return NULL;
2397
2398         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2399 }
2400 EXPORT_SYMBOL(transport_kmap_data_sg);
2401
2402 void transport_kunmap_data_sg(struct se_cmd *cmd)
2403 {
2404         if (!cmd->t_data_nents) {
2405                 return;
2406         } else if (cmd->t_data_nents == 1) {
2407                 kunmap(sg_page(cmd->t_data_sg));
2408                 return;
2409         }
2410
2411         vunmap(cmd->t_data_vmap);
2412         cmd->t_data_vmap = NULL;
2413 }
2414 EXPORT_SYMBOL(transport_kunmap_data_sg);
2415
2416 int
2417 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2418                  bool zero_page, bool chainable)
2419 {
2420         struct scatterlist *sg;
2421         struct page *page;
2422         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2423         unsigned int nalloc, nent;
2424         int i = 0;
2425
2426         nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2427         if (chainable)
2428                 nalloc++;
2429         sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2430         if (!sg)
2431                 return -ENOMEM;
2432
2433         sg_init_table(sg, nalloc);
2434
2435         while (length) {
2436                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2437                 page = alloc_page(GFP_KERNEL | zero_flag);
2438                 if (!page)
2439                         goto out;
2440
2441                 sg_set_page(&sg[i], page, page_len, 0);
2442                 length -= page_len;
2443                 i++;
2444         }
2445         *sgl = sg;
2446         *nents = nent;
2447         return 0;
2448
2449 out:
2450         while (i > 0) {
2451                 i--;
2452                 __free_page(sg_page(&sg[i]));
2453         }
2454         kfree(sg);
2455         return -ENOMEM;
2456 }
2457 EXPORT_SYMBOL(target_alloc_sgl);
2458
2459 /*
2460  * Allocate any required resources to execute the command.  For writes we
2461  * might not have the payload yet, so notify the fabric via a call to
2462  * ->write_pending instead. Otherwise place it on the execution queue.
2463  */
2464 sense_reason_t
2465 transport_generic_new_cmd(struct se_cmd *cmd)
2466 {
2467         unsigned long flags;
2468         int ret = 0;
2469         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2470
2471         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2472             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2473                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2474                                        cmd->prot_length, true, false);
2475                 if (ret < 0)
2476                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2477         }
2478
2479         /*
2480          * Determine is the TCM fabric module has already allocated physical
2481          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2482          * beforehand.
2483          */
2484         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2485             cmd->data_length) {
2486
2487                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2488                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2489                         u32 bidi_length;
2490
2491                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2492                                 bidi_length = cmd->t_task_nolb *
2493                                               cmd->se_dev->dev_attrib.block_size;
2494                         else
2495                                 bidi_length = cmd->data_length;
2496
2497                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2498                                                &cmd->t_bidi_data_nents,
2499                                                bidi_length, zero_flag, false);
2500                         if (ret < 0)
2501                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2502                 }
2503
2504                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2505                                        cmd->data_length, zero_flag, false);
2506                 if (ret < 0)
2507                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2508         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2509                     cmd->data_length) {
2510                 /*
2511                  * Special case for COMPARE_AND_WRITE with fabrics
2512                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2513                  */
2514                 u32 caw_length = cmd->t_task_nolb *
2515                                  cmd->se_dev->dev_attrib.block_size;
2516
2517                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2518                                        &cmd->t_bidi_data_nents,
2519                                        caw_length, zero_flag, false);
2520                 if (ret < 0)
2521                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2522         }
2523         /*
2524          * If this command is not a write we can execute it right here,
2525          * for write buffers we need to notify the fabric driver first
2526          * and let it call back once the write buffers are ready.
2527          */
2528         target_add_to_state_list(cmd);
2529         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2530                 target_execute_cmd(cmd);
2531                 return 0;
2532         }
2533
2534         spin_lock_irqsave(&cmd->t_state_lock, flags);
2535         cmd->t_state = TRANSPORT_WRITE_PENDING;
2536         /*
2537          * Determine if frontend context caller is requesting the stopping of
2538          * this command for frontend exceptions.
2539          */
2540         if (cmd->transport_state & CMD_T_STOP) {
2541                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2542                          __func__, __LINE__, cmd->tag);
2543
2544                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2545
2546                 complete_all(&cmd->t_transport_stop_comp);
2547                 return 0;
2548         }
2549         cmd->transport_state &= ~CMD_T_ACTIVE;
2550         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2551
2552         ret = cmd->se_tfo->write_pending(cmd);
2553         if (ret)
2554                 goto queue_full;
2555
2556         return 0;
2557
2558 queue_full:
2559         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2560         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2561         return 0;
2562 }
2563 EXPORT_SYMBOL(transport_generic_new_cmd);
2564
2565 static void transport_write_pending_qf(struct se_cmd *cmd)
2566 {
2567         unsigned long flags;
2568         int ret;
2569         bool stop;
2570
2571         spin_lock_irqsave(&cmd->t_state_lock, flags);
2572         stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2573         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2574
2575         if (stop) {
2576                 pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2577                         __func__, __LINE__, cmd->tag);
2578                 complete_all(&cmd->t_transport_stop_comp);
2579                 return;
2580         }
2581
2582         ret = cmd->se_tfo->write_pending(cmd);
2583         if (ret) {
2584                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2585                          cmd);
2586                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2587         }
2588 }
2589
2590 static bool
2591 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2592                            unsigned long *flags);
2593
2594 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2595 {
2596         unsigned long flags;
2597
2598         spin_lock_irqsave(&cmd->t_state_lock, flags);
2599         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2600         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2601 }
2602
2603 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2604 {
2605         int ret = 0;
2606         bool aborted = false, tas = false;
2607
2608         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2609                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2610                         target_wait_free_cmd(cmd, &aborted, &tas);
2611
2612                 if (!aborted || tas)
2613                         ret = target_put_sess_cmd(cmd);
2614         } else {
2615                 if (wait_for_tasks)
2616                         target_wait_free_cmd(cmd, &aborted, &tas);
2617                 /*
2618                  * Handle WRITE failure case where transport_generic_new_cmd()
2619                  * has already added se_cmd to state_list, but fabric has
2620                  * failed command before I/O submission.
2621                  */
2622                 if (cmd->state_active)
2623                         target_remove_from_state_list(cmd);
2624
2625                 if (cmd->se_lun)
2626                         transport_lun_remove_cmd(cmd);
2627
2628                 if (!aborted || tas)
2629                         ret = target_put_sess_cmd(cmd);
2630         }
2631         /*
2632          * If the task has been internally aborted due to TMR ABORT_TASK
2633          * or LUN_RESET, target_core_tmr.c is responsible for performing
2634          * the remaining calls to target_put_sess_cmd(), and not the
2635          * callers of this function.
2636          */
2637         if (aborted) {
2638                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2639                 wait_for_completion(&cmd->cmd_wait_comp);
2640                 cmd->se_tfo->release_cmd(cmd);
2641                 ret = 1;
2642         }
2643         return ret;
2644 }
2645 EXPORT_SYMBOL(transport_generic_free_cmd);
2646
2647 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2648  * @se_cmd:     command descriptor to add
2649  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2650  */
2651 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2652 {
2653         struct se_session *se_sess = se_cmd->se_sess;
2654         unsigned long flags;
2655         int ret = 0;
2656
2657         /*
2658          * Add a second kref if the fabric caller is expecting to handle
2659          * fabric acknowledgement that requires two target_put_sess_cmd()
2660          * invocations before se_cmd descriptor release.
2661          */
2662         if (ack_kref) {
2663                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2664                         return -EINVAL;
2665
2666                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2667         }
2668
2669         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2670         if (se_sess->sess_tearing_down) {
2671                 ret = -ESHUTDOWN;
2672                 goto out;
2673         }
2674         se_cmd->transport_state |= CMD_T_PRE_EXECUTE;
2675         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2676 out:
2677         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2678
2679         if (ret && ack_kref)
2680                 target_put_sess_cmd(se_cmd);
2681
2682         return ret;
2683 }
2684 EXPORT_SYMBOL(target_get_sess_cmd);
2685
2686 static void target_free_cmd_mem(struct se_cmd *cmd)
2687 {
2688         transport_free_pages(cmd);
2689
2690         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2691                 core_tmr_release_req(cmd->se_tmr_req);
2692         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2693                 kfree(cmd->t_task_cdb);
2694 }
2695
2696 static void target_release_cmd_kref(struct kref *kref)
2697 {
2698         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2699         struct se_session *se_sess = se_cmd->se_sess;
2700         unsigned long flags;
2701         bool fabric_stop;
2702
2703         if (se_sess) {
2704                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2705
2706                 spin_lock(&se_cmd->t_state_lock);
2707                 fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2708                               (se_cmd->transport_state & CMD_T_ABORTED);
2709                 spin_unlock(&se_cmd->t_state_lock);
2710
2711                 if (se_cmd->cmd_wait_set || fabric_stop) {
2712                         list_del_init(&se_cmd->se_cmd_list);
2713                         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2714                         target_free_cmd_mem(se_cmd);
2715                         complete(&se_cmd->cmd_wait_comp);
2716                         return;
2717                 }
2718                 list_del_init(&se_cmd->se_cmd_list);
2719                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2720         }
2721
2722         target_free_cmd_mem(se_cmd);
2723         se_cmd->se_tfo->release_cmd(se_cmd);
2724 }
2725
2726 /**
2727  * target_put_sess_cmd - decrease the command reference count
2728  * @se_cmd:     command to drop a reference from
2729  *
2730  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2731  * refcount to drop to zero. Returns zero otherwise.
2732  */
2733 int target_put_sess_cmd(struct se_cmd *se_cmd)
2734 {
2735         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2736 }
2737 EXPORT_SYMBOL(target_put_sess_cmd);
2738
2739 static const char *data_dir_name(enum dma_data_direction d)
2740 {
2741         switch (d) {
2742         case DMA_BIDIRECTIONAL: return "BIDI";
2743         case DMA_TO_DEVICE:     return "WRITE";
2744         case DMA_FROM_DEVICE:   return "READ";
2745         case DMA_NONE:          return "NONE";
2746         }
2747
2748         return "(?)";
2749 }
2750
2751 static const char *cmd_state_name(enum transport_state_table t)
2752 {
2753         switch (t) {
2754         case TRANSPORT_NO_STATE:        return "NO_STATE";
2755         case TRANSPORT_NEW_CMD:         return "NEW_CMD";
2756         case TRANSPORT_WRITE_PENDING:   return "WRITE_PENDING";
2757         case TRANSPORT_PROCESSING:      return "PROCESSING";
2758         case TRANSPORT_COMPLETE:        return "COMPLETE";
2759         case TRANSPORT_ISTATE_PROCESSING:
2760                                         return "ISTATE_PROCESSING";
2761         case TRANSPORT_COMPLETE_QF_WP:  return "COMPLETE_QF_WP";
2762         case TRANSPORT_COMPLETE_QF_OK:  return "COMPLETE_QF_OK";
2763         case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
2764         }
2765
2766         return "(?)";
2767 }
2768
2769 static void target_append_str(char **str, const char *txt)
2770 {
2771         char *prev = *str;
2772
2773         *str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
2774                 kstrdup(txt, GFP_ATOMIC);
2775         kfree(prev);
2776 }
2777
2778 /*
2779  * Convert a transport state bitmask into a string. The caller is
2780  * responsible for freeing the returned pointer.
2781  */
2782 static char *target_ts_to_str(u32 ts)
2783 {
2784         char *str = NULL;
2785
2786         if (ts & CMD_T_ABORTED)
2787                 target_append_str(&str, "aborted");
2788         if (ts & CMD_T_ACTIVE)
2789                 target_append_str(&str, "active");
2790         if (ts & CMD_T_COMPLETE)
2791                 target_append_str(&str, "complete");
2792         if (ts & CMD_T_SENT)
2793                 target_append_str(&str, "sent");
2794         if (ts & CMD_T_STOP)
2795                 target_append_str(&str, "stop");
2796         if (ts & CMD_T_FABRIC_STOP)
2797                 target_append_str(&str, "fabric_stop");
2798
2799         return str;
2800 }
2801
2802 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
2803 {
2804         switch (tmf) {
2805         case TMR_ABORT_TASK:            return "ABORT_TASK";
2806         case TMR_ABORT_TASK_SET:        return "ABORT_TASK_SET";
2807         case TMR_CLEAR_ACA:             return "CLEAR_ACA";
2808         case TMR_CLEAR_TASK_SET:        return "CLEAR_TASK_SET";
2809         case TMR_LUN_RESET:             return "LUN_RESET";
2810         case TMR_TARGET_WARM_RESET:     return "TARGET_WARM_RESET";
2811         case TMR_TARGET_COLD_RESET:     return "TARGET_COLD_RESET";
2812         case TMR_UNKNOWN:               break;
2813         }
2814         return "(?)";
2815 }
2816
2817 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
2818 {
2819         char *ts_str = target_ts_to_str(cmd->transport_state);
2820         const u8 *cdb = cmd->t_task_cdb;
2821         struct se_tmr_req *tmf = cmd->se_tmr_req;
2822
2823         if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2824                 pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
2825                          pfx, cdb[0], cdb[1], cmd->tag,
2826                          data_dir_name(cmd->data_direction),
2827                          cmd->se_tfo->get_cmd_state(cmd),
2828                          cmd_state_name(cmd->t_state), cmd->data_length,
2829                          kref_read(&cmd->cmd_kref), ts_str);
2830         } else {
2831                 pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
2832                          pfx, target_tmf_name(tmf->function), cmd->tag,
2833                          tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
2834                          cmd_state_name(cmd->t_state),
2835                          kref_read(&cmd->cmd_kref), ts_str);
2836         }
2837         kfree(ts_str);
2838 }
2839 EXPORT_SYMBOL(target_show_cmd);
2840
2841 /* target_sess_cmd_list_set_waiting - Flag all commands in
2842  *         sess_cmd_list to complete cmd_wait_comp.  Set
2843  *         sess_tearing_down so no more commands are queued.
2844  * @se_sess:    session to flag
2845  */
2846 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2847 {
2848         struct se_cmd *se_cmd, *tmp_cmd;
2849         unsigned long flags;
2850         int rc;
2851
2852         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2853         if (se_sess->sess_tearing_down) {
2854                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2855                 return;
2856         }
2857         se_sess->sess_tearing_down = 1;
2858         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2859
2860         list_for_each_entry_safe(se_cmd, tmp_cmd,
2861                                  &se_sess->sess_wait_list, se_cmd_list) {
2862                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2863                 if (rc) {
2864                         se_cmd->cmd_wait_set = 1;
2865                         spin_lock(&se_cmd->t_state_lock);
2866                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2867                         spin_unlock(&se_cmd->t_state_lock);
2868                 } else
2869                         list_del_init(&se_cmd->se_cmd_list);
2870         }
2871
2872         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2873 }
2874 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2875
2876 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2877  * @se_sess:    session to wait for active I/O
2878  */
2879 void target_wait_for_sess_cmds(struct se_session *se_sess)
2880 {
2881         struct se_cmd *se_cmd, *tmp_cmd;
2882         unsigned long flags;
2883         bool tas;
2884
2885         list_for_each_entry_safe(se_cmd, tmp_cmd,
2886                                 &se_sess->sess_wait_list, se_cmd_list) {
2887                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2888                         " %d\n", se_cmd, se_cmd->t_state,
2889                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2890
2891                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2892                 tas = (se_cmd->transport_state & CMD_T_TAS);
2893                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2894
2895                 if (!target_put_sess_cmd(se_cmd)) {
2896                         if (tas)
2897                                 target_put_sess_cmd(se_cmd);
2898                 }
2899
2900                 wait_for_completion(&se_cmd->cmd_wait_comp);
2901                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2902                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2903                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2904
2905                 se_cmd->se_tfo->release_cmd(se_cmd);
2906         }
2907
2908         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2909         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2910         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2911
2912 }
2913 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2914
2915 static void target_lun_confirm(struct percpu_ref *ref)
2916 {
2917         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2918
2919         complete(&lun->lun_ref_comp);
2920 }
2921
2922 void transport_clear_lun_ref(struct se_lun *lun)
2923 {
2924         /*
2925          * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2926          * the initial reference and schedule confirm kill to be
2927          * executed after one full RCU grace period has completed.
2928          */
2929         percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2930         /*
2931          * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2932          * to call target_lun_confirm after lun->lun_ref has been marked
2933          * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2934          * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2935          * fails for all new incoming I/O.
2936          */
2937         wait_for_completion(&lun->lun_ref_comp);
2938         /*
2939          * The second completion waits for percpu_ref_put_many() to
2940          * invoke ->release() after lun->lun_ref has switched to
2941          * atomic_t mode, and lun->lun_ref.count has reached zero.
2942          *
2943          * At this point all target-core lun->lun_ref references have
2944          * been dropped via transport_lun_remove_cmd(), and it's safe
2945          * to proceed with the remaining LUN shutdown.
2946          */
2947         wait_for_completion(&lun->lun_shutdown_comp);
2948 }
2949
2950 static bool
2951 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2952                            bool *aborted, bool *tas, unsigned long *flags)
2953         __releases(&cmd->t_state_lock)
2954         __acquires(&cmd->t_state_lock)
2955 {
2956
2957         assert_spin_locked(&cmd->t_state_lock);
2958         WARN_ON_ONCE(!irqs_disabled());
2959
2960         if (fabric_stop)
2961                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2962
2963         if (cmd->transport_state & CMD_T_ABORTED)
2964                 *aborted = true;
2965
2966         if (cmd->transport_state & CMD_T_TAS)
2967                 *tas = true;
2968
2969         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2970             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2971                 return false;
2972
2973         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2974             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2975                 return false;
2976
2977         if (!(cmd->transport_state & CMD_T_ACTIVE))
2978                 return false;
2979
2980         if (fabric_stop && *aborted)
2981                 return false;
2982
2983         cmd->transport_state |= CMD_T_STOP;
2984
2985         target_show_cmd("wait_for_tasks: Stopping ", cmd);
2986
2987         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2988
2989         while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
2990                                             180 * HZ))
2991                 target_show_cmd("wait for tasks: ", cmd);
2992
2993         spin_lock_irqsave(&cmd->t_state_lock, *flags);
2994         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2995
2996         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2997                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2998
2999         return true;
3000 }
3001
3002 /**
3003  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3004  * @cmd: command to wait on
3005  */
3006 bool transport_wait_for_tasks(struct se_cmd *cmd)
3007 {
3008         unsigned long flags;
3009         bool ret, aborted = false, tas = false;
3010
3011         spin_lock_irqsave(&cmd->t_state_lock, flags);
3012         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3013         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3014
3015         return ret;
3016 }
3017 EXPORT_SYMBOL(transport_wait_for_tasks);
3018
3019 struct sense_info {
3020         u8 key;
3021         u8 asc;
3022         u8 ascq;
3023         bool add_sector_info;
3024 };
3025
3026 static const struct sense_info sense_info_table[] = {
3027         [TCM_NO_SENSE] = {
3028                 .key = NOT_READY
3029         },
3030         [TCM_NON_EXISTENT_LUN] = {
3031                 .key = ILLEGAL_REQUEST,
3032                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3033         },
3034         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
3035                 .key = ILLEGAL_REQUEST,
3036                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3037         },
3038         [TCM_SECTOR_COUNT_TOO_MANY] = {
3039                 .key = ILLEGAL_REQUEST,
3040                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3041         },
3042         [TCM_UNKNOWN_MODE_PAGE] = {
3043                 .key = ILLEGAL_REQUEST,
3044                 .asc = 0x24, /* INVALID FIELD IN CDB */
3045         },
3046         [TCM_CHECK_CONDITION_ABORT_CMD] = {
3047                 .key = ABORTED_COMMAND,
3048                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3049                 .ascq = 0x03,
3050         },
3051         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
3052                 .key = ABORTED_COMMAND,
3053                 .asc = 0x0c, /* WRITE ERROR */
3054                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3055         },
3056         [TCM_INVALID_CDB_FIELD] = {
3057                 .key = ILLEGAL_REQUEST,
3058                 .asc = 0x24, /* INVALID FIELD IN CDB */
3059         },
3060         [TCM_INVALID_PARAMETER_LIST] = {
3061                 .key = ILLEGAL_REQUEST,
3062                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3063         },
3064         [TCM_TOO_MANY_TARGET_DESCS] = {
3065                 .key = ILLEGAL_REQUEST,
3066                 .asc = 0x26,
3067                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3068         },
3069         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3070                 .key = ILLEGAL_REQUEST,
3071                 .asc = 0x26,
3072                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3073         },
3074         [TCM_TOO_MANY_SEGMENT_DESCS] = {
3075                 .key = ILLEGAL_REQUEST,
3076                 .asc = 0x26,
3077                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3078         },
3079         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3080                 .key = ILLEGAL_REQUEST,
3081                 .asc = 0x26,
3082                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3083         },
3084         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3085                 .key = ILLEGAL_REQUEST,
3086                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3087         },
3088         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3089                 .key = ILLEGAL_REQUEST,
3090                 .asc = 0x0c, /* WRITE ERROR */
3091                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3092         },
3093         [TCM_SERVICE_CRC_ERROR] = {
3094                 .key = ABORTED_COMMAND,
3095                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3096                 .ascq = 0x05, /* N/A */
3097         },
3098         [TCM_SNACK_REJECTED] = {
3099                 .key = ABORTED_COMMAND,
3100                 .asc = 0x11, /* READ ERROR */
3101                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3102         },
3103         [TCM_WRITE_PROTECTED] = {
3104                 .key = DATA_PROTECT,
3105                 .asc = 0x27, /* WRITE PROTECTED */
3106         },
3107         [TCM_ADDRESS_OUT_OF_RANGE] = {
3108                 .key = ILLEGAL_REQUEST,
3109                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3110         },
3111         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3112                 .key = UNIT_ATTENTION,
3113         },
3114         [TCM_CHECK_CONDITION_NOT_READY] = {
3115                 .key = NOT_READY,
3116         },
3117         [TCM_MISCOMPARE_VERIFY] = {
3118                 .key = MISCOMPARE,
3119                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3120                 .ascq = 0x00,
3121         },
3122         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3123                 .key = ABORTED_COMMAND,
3124                 .asc = 0x10,
3125                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3126                 .add_sector_info = true,
3127         },
3128         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3129                 .key = ABORTED_COMMAND,
3130                 .asc = 0x10,
3131                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3132                 .add_sector_info = true,
3133         },
3134         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3135                 .key = ABORTED_COMMAND,
3136                 .asc = 0x10,
3137                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3138                 .add_sector_info = true,
3139         },
3140         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3141                 .key = COPY_ABORTED,
3142                 .asc = 0x0d,
3143                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3144
3145         },
3146         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3147                 /*
3148                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
3149                  * Solaris initiators.  Returning NOT READY instead means the
3150                  * operations will be retried a finite number of times and we
3151                  * can survive intermittent errors.
3152                  */
3153                 .key = NOT_READY,
3154                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3155         },
3156         [TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3157                 /*
3158                  * From spc4r22 section5.7.7,5.7.8
3159                  * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3160                  * or a REGISTER AND IGNORE EXISTING KEY service action or
3161                  * REGISTER AND MOVE service actionis attempted,
3162                  * but there are insufficient device server resources to complete the
3163                  * operation, then the command shall be terminated with CHECK CONDITION
3164                  * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3165                  * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3166                  */
3167                 .key = ILLEGAL_REQUEST,
3168                 .asc = 0x55,
3169                 .ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3170         },
3171 };
3172
3173 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3174 {
3175         const struct sense_info *si;
3176         u8 *buffer = cmd->sense_buffer;
3177         int r = (__force int)reason;
3178         u8 asc, ascq;
3179         bool desc_format = target_sense_desc_format(cmd->se_dev);
3180
3181         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
3182                 si = &sense_info_table[r];
3183         else
3184                 si = &sense_info_table[(__force int)
3185                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3186
3187         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3188                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
3189                 WARN_ON_ONCE(asc == 0);
3190         } else if (si->asc == 0) {
3191                 WARN_ON_ONCE(cmd->scsi_asc == 0);
3192                 asc = cmd->scsi_asc;
3193                 ascq = cmd->scsi_ascq;
3194         } else {
3195                 asc = si->asc;
3196                 ascq = si->ascq;
3197         }
3198
3199         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
3200         if (si->add_sector_info)
3201                 return scsi_set_sense_information(buffer,
3202                                                   cmd->scsi_sense_length,
3203                                                   cmd->bad_sector);
3204
3205         return 0;
3206 }
3207
3208 int
3209 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3210                 sense_reason_t reason, int from_transport)
3211 {
3212         unsigned long flags;
3213
3214         spin_lock_irqsave(&cmd->t_state_lock, flags);
3215         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3216                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3217                 return 0;
3218         }
3219         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3220         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3221
3222         if (!from_transport) {
3223                 int rc;
3224
3225                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3226                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3227                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3228                 rc = translate_sense_reason(cmd, reason);
3229                 if (rc)
3230                         return rc;
3231         }
3232
3233         trace_target_cmd_complete(cmd);
3234         return cmd->se_tfo->queue_status(cmd);
3235 }
3236 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3237
3238 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3239         __releases(&cmd->t_state_lock)
3240         __acquires(&cmd->t_state_lock)
3241 {
3242         int ret;
3243
3244         assert_spin_locked(&cmd->t_state_lock);
3245         WARN_ON_ONCE(!irqs_disabled());
3246
3247         if (!(cmd->transport_state & CMD_T_ABORTED))
3248                 return 0;
3249         /*
3250          * If cmd has been aborted but either no status is to be sent or it has
3251          * already been sent, just return
3252          */
3253         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3254                 if (send_status)
3255                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3256                 return 1;
3257         }
3258
3259         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3260                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3261
3262         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3263         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3264         trace_target_cmd_complete(cmd);
3265
3266         spin_unlock_irq(&cmd->t_state_lock);
3267         ret = cmd->se_tfo->queue_status(cmd);
3268         if (ret)
3269                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3270         spin_lock_irq(&cmd->t_state_lock);
3271
3272         return 1;
3273 }
3274
3275 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3276 {
3277         int ret;
3278
3279         spin_lock_irq(&cmd->t_state_lock);
3280         ret = __transport_check_aborted_status(cmd, send_status);
3281         spin_unlock_irq(&cmd->t_state_lock);
3282
3283         return ret;
3284 }
3285 EXPORT_SYMBOL(transport_check_aborted_status);
3286
3287 void transport_send_task_abort(struct se_cmd *cmd)
3288 {
3289         unsigned long flags;
3290         int ret;
3291
3292         spin_lock_irqsave(&cmd->t_state_lock, flags);
3293         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3294                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3295                 return;
3296         }
3297         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3298
3299         /*
3300          * If there are still expected incoming fabric WRITEs, we wait
3301          * until until they have completed before sending a TASK_ABORTED
3302          * response.  This response with TASK_ABORTED status will be
3303          * queued back to fabric module by transport_check_aborted_status().
3304          */
3305         if (cmd->data_direction == DMA_TO_DEVICE) {
3306                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3307                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3308                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3309                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3310                                 goto send_abort;
3311                         }
3312                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3313                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3314                         return;
3315                 }
3316         }
3317 send_abort:
3318         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3319
3320         transport_lun_remove_cmd(cmd);
3321
3322         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3323                  cmd->t_task_cdb[0], cmd->tag);
3324
3325         trace_target_cmd_complete(cmd);
3326         ret = cmd->se_tfo->queue_status(cmd);
3327         if (ret)
3328                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3329 }
3330
3331 static void target_tmr_work(struct work_struct *work)
3332 {
3333         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3334         struct se_device *dev = cmd->se_dev;
3335         struct se_tmr_req *tmr = cmd->se_tmr_req;
3336         unsigned long flags;
3337         int ret;
3338
3339         spin_lock_irqsave(&cmd->t_state_lock, flags);
3340         if (cmd->transport_state & CMD_T_ABORTED) {
3341                 tmr->response = TMR_FUNCTION_REJECTED;
3342                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3343                 goto check_stop;
3344         }
3345         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3346
3347         switch (tmr->function) {
3348         case TMR_ABORT_TASK:
3349                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3350                 break;
3351         case TMR_ABORT_TASK_SET:
3352         case TMR_CLEAR_ACA:
3353         case TMR_CLEAR_TASK_SET:
3354                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3355                 break;
3356         case TMR_LUN_RESET:
3357                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3358                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3359                                          TMR_FUNCTION_REJECTED;
3360                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3361                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3362                                                cmd->orig_fe_lun, 0x29,
3363                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3364                 }
3365                 break;
3366         case TMR_TARGET_WARM_RESET:
3367                 tmr->response = TMR_FUNCTION_REJECTED;
3368                 break;
3369         case TMR_TARGET_COLD_RESET:
3370                 tmr->response = TMR_FUNCTION_REJECTED;
3371                 break;
3372         default:
3373                 pr_err("Uknown TMR function: 0x%02x.\n",
3374                                 tmr->function);
3375                 tmr->response = TMR_FUNCTION_REJECTED;
3376                 break;
3377         }
3378
3379         spin_lock_irqsave(&cmd->t_state_lock, flags);
3380         if (cmd->transport_state & CMD_T_ABORTED) {
3381                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3382                 goto check_stop;
3383         }
3384         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3385
3386         cmd->se_tfo->queue_tm_rsp(cmd);
3387
3388 check_stop:
3389         transport_lun_remove_cmd(cmd);
3390         transport_cmd_check_stop_to_fabric(cmd);
3391 }
3392
3393 int transport_generic_handle_tmr(
3394         struct se_cmd *cmd)
3395 {
3396         unsigned long flags;
3397         bool aborted = false;
3398
3399         spin_lock_irqsave(&cmd->t_state_lock, flags);
3400         if (cmd->transport_state & CMD_T_ABORTED) {
3401                 aborted = true;
3402         } else {
3403                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3404                 cmd->transport_state |= CMD_T_ACTIVE;
3405         }
3406         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3407
3408         if (aborted) {
3409                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3410                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3411                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3412                 transport_lun_remove_cmd(cmd);
3413                 transport_cmd_check_stop_to_fabric(cmd);
3414                 return 0;
3415         }
3416
3417         INIT_WORK(&cmd->work, target_tmr_work);
3418         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3419         return 0;
3420 }
3421 EXPORT_SYMBOL(transport_generic_handle_tmr);
3422
3423 bool
3424 target_check_wce(struct se_device *dev)
3425 {
3426         bool wce = false;
3427
3428         if (dev->transport->get_write_cache)
3429                 wce = dev->transport->get_write_cache(dev);
3430         else if (dev->dev_attrib.emulate_write_cache > 0)
3431                 wce = true;
3432
3433         return wce;
3434 }
3435
3436 bool
3437 target_check_fua(struct se_device *dev)
3438 {
3439         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3440 }