drivers/target/target_core_transport.c

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