linux/drivers/target/target_core_transport.c
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   1/*******************************************************************************
   2 * Filename:  target_core_transport.c
   3 *
   4 * This file contains the Generic Target Engine Core.
   5 *
   6 * (c) Copyright 2002-2012 RisingTide Systems LLC.
   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/blkdev.h>
  32#include <linux/spinlock.h>
  33#include <linux/kthread.h>
  34#include <linux/in.h>
  35#include <linux/cdrom.h>
  36#include <linux/module.h>
  37#include <linux/ratelimit.h>
  38#include <asm/unaligned.h>
  39#include <net/sock.h>
  40#include <net/tcp.h>
  41#include <scsi/scsi.h>
  42#include <scsi/scsi_cmnd.h>
  43#include <scsi/scsi_tcq.h>
  44
  45#include <target/target_core_base.h>
  46#include <target/target_core_backend.h>
  47#include <target/target_core_fabric.h>
  48#include <target/target_core_configfs.h>
  49
  50#include "target_core_internal.h"
  51#include "target_core_alua.h"
  52#include "target_core_pr.h"
  53#include "target_core_ua.h"
  54
  55static struct workqueue_struct *target_completion_wq;
  56static struct kmem_cache *se_sess_cache;
  57struct kmem_cache *se_ua_cache;
  58struct kmem_cache *t10_pr_reg_cache;
  59struct kmem_cache *t10_alua_lu_gp_cache;
  60struct kmem_cache *t10_alua_lu_gp_mem_cache;
  61struct kmem_cache *t10_alua_tg_pt_gp_cache;
  62struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
  63
  64static void transport_complete_task_attr(struct se_cmd *cmd);
  65static void transport_handle_queue_full(struct se_cmd *cmd,
  66                struct se_device *dev);
  67static int transport_generic_get_mem(struct se_cmd *cmd);
  68static int target_get_sess_cmd(struct se_session *, struct se_cmd *, bool);
  69static void transport_put_cmd(struct se_cmd *cmd);
  70static void target_complete_ok_work(struct work_struct *work);
  71
  72int 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_tg_pt_gp_mem_cache = kmem_cache_create(
 122                        "t10_alua_tg_pt_gp_mem_cache",
 123                        sizeof(struct t10_alua_tg_pt_gp_member),
 124                        __alignof__(struct t10_alua_tg_pt_gp_member),
 125                        0, NULL);
 126        if (!t10_alua_tg_pt_gp_mem_cache) {
 127                pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 128                                "mem_t failed\n");
 129                goto out_free_tg_pt_gp_cache;
 130        }
 131
 132        target_completion_wq = alloc_workqueue("target_completion",
 133                                               WQ_MEM_RECLAIM, 0);
 134        if (!target_completion_wq)
 135                goto out_free_tg_pt_gp_mem_cache;
 136
 137        return 0;
 138
 139out_free_tg_pt_gp_mem_cache:
 140        kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 141out_free_tg_pt_gp_cache:
 142        kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 143out_free_lu_gp_mem_cache:
 144        kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 145out_free_lu_gp_cache:
 146        kmem_cache_destroy(t10_alua_lu_gp_cache);
 147out_free_pr_reg_cache:
 148        kmem_cache_destroy(t10_pr_reg_cache);
 149out_free_ua_cache:
 150        kmem_cache_destroy(se_ua_cache);
 151out_free_sess_cache:
 152        kmem_cache_destroy(se_sess_cache);
 153out:
 154        return -ENOMEM;
 155}
 156
 157void release_se_kmem_caches(void)
 158{
 159        destroy_workqueue(target_completion_wq);
 160        kmem_cache_destroy(se_sess_cache);
 161        kmem_cache_destroy(se_ua_cache);
 162        kmem_cache_destroy(t10_pr_reg_cache);
 163        kmem_cache_destroy(t10_alua_lu_gp_cache);
 164        kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 165        kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 166        kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 167}
 168
 169/* This code ensures unique mib indexes are handed out. */
 170static DEFINE_SPINLOCK(scsi_mib_index_lock);
 171static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 172
 173/*
 174 * Allocate a new row index for the entry type specified
 175 */
 176u32 scsi_get_new_index(scsi_index_t type)
 177{
 178        u32 new_index;
 179
 180        BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 181
 182        spin_lock(&scsi_mib_index_lock);
 183        new_index = ++scsi_mib_index[type];
 184        spin_unlock(&scsi_mib_index_lock);
 185
 186        return new_index;
 187}
 188
 189void transport_subsystem_check_init(void)
 190{
 191        int ret;
 192        static int sub_api_initialized;
 193
 194        if (sub_api_initialized)
 195                return;
 196
 197        ret = request_module("target_core_iblock");
 198        if (ret != 0)
 199                pr_err("Unable to load target_core_iblock\n");
 200
 201        ret = request_module("target_core_file");
 202        if (ret != 0)
 203                pr_err("Unable to load target_core_file\n");
 204
 205        ret = request_module("target_core_pscsi");
 206        if (ret != 0)
 207                pr_err("Unable to load target_core_pscsi\n");
 208
 209        sub_api_initialized = 1;
 210}
 211
 212struct se_session *transport_init_session(void)
 213{
 214        struct se_session *se_sess;
 215
 216        se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 217        if (!se_sess) {
 218                pr_err("Unable to allocate struct se_session from"
 219                                " se_sess_cache\n");
 220                return ERR_PTR(-ENOMEM);
 221        }
 222        INIT_LIST_HEAD(&se_sess->sess_list);
 223        INIT_LIST_HEAD(&se_sess->sess_acl_list);
 224        INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 225        spin_lock_init(&se_sess->sess_cmd_lock);
 226        kref_init(&se_sess->sess_kref);
 227
 228        return se_sess;
 229}
 230EXPORT_SYMBOL(transport_init_session);
 231
 232/*
 233 * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 234 */
 235void __transport_register_session(
 236        struct se_portal_group *se_tpg,
 237        struct se_node_acl *se_nacl,
 238        struct se_session *se_sess,
 239        void *fabric_sess_ptr)
 240{
 241        unsigned char buf[PR_REG_ISID_LEN];
 242
 243        se_sess->se_tpg = se_tpg;
 244        se_sess->fabric_sess_ptr = fabric_sess_ptr;
 245        /*
 246         * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 247         *
 248         * Only set for struct se_session's that will actually be moving I/O.
 249         * eg: *NOT* discovery sessions.
 250         */
 251        if (se_nacl) {
 252                /*
 253                 * If the fabric module supports an ISID based TransportID,
 254                 * save this value in binary from the fabric I_T Nexus now.
 255                 */
 256                if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 257                        memset(&buf[0], 0, PR_REG_ISID_LEN);
 258                        se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 259                                        &buf[0], PR_REG_ISID_LEN);
 260                        se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 261                }
 262                kref_get(&se_nacl->acl_kref);
 263
 264                spin_lock_irq(&se_nacl->nacl_sess_lock);
 265                /*
 266                 * The se_nacl->nacl_sess pointer will be set to the
 267                 * last active I_T Nexus for each struct se_node_acl.
 268                 */
 269                se_nacl->nacl_sess = se_sess;
 270
 271                list_add_tail(&se_sess->sess_acl_list,
 272                              &se_nacl->acl_sess_list);
 273                spin_unlock_irq(&se_nacl->nacl_sess_lock);
 274        }
 275        list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 276
 277        pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 278                se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 279}
 280EXPORT_SYMBOL(__transport_register_session);
 281
 282void transport_register_session(
 283        struct se_portal_group *se_tpg,
 284        struct se_node_acl *se_nacl,
 285        struct se_session *se_sess,
 286        void *fabric_sess_ptr)
 287{
 288        unsigned long flags;
 289
 290        spin_lock_irqsave(&se_tpg->session_lock, flags);
 291        __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 292        spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 293}
 294EXPORT_SYMBOL(transport_register_session);
 295
 296static void target_release_session(struct kref *kref)
 297{
 298        struct se_session *se_sess = container_of(kref,
 299                        struct se_session, sess_kref);
 300        struct se_portal_group *se_tpg = se_sess->se_tpg;
 301
 302        se_tpg->se_tpg_tfo->close_session(se_sess);
 303}
 304
 305void target_get_session(struct se_session *se_sess)
 306{
 307        kref_get(&se_sess->sess_kref);
 308}
 309EXPORT_SYMBOL(target_get_session);
 310
 311void target_put_session(struct se_session *se_sess)
 312{
 313        struct se_portal_group *tpg = se_sess->se_tpg;
 314
 315        if (tpg->se_tpg_tfo->put_session != NULL) {
 316                tpg->se_tpg_tfo->put_session(se_sess);
 317                return;
 318        }
 319        kref_put(&se_sess->sess_kref, target_release_session);
 320}
 321EXPORT_SYMBOL(target_put_session);
 322
 323static void target_complete_nacl(struct kref *kref)
 324{
 325        struct se_node_acl *nacl = container_of(kref,
 326                                struct se_node_acl, acl_kref);
 327
 328        complete(&nacl->acl_free_comp);
 329}
 330
 331void target_put_nacl(struct se_node_acl *nacl)
 332{
 333        kref_put(&nacl->acl_kref, target_complete_nacl);
 334}
 335
 336void transport_deregister_session_configfs(struct se_session *se_sess)
 337{
 338        struct se_node_acl *se_nacl;
 339        unsigned long flags;
 340        /*
 341         * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 342         */
 343        se_nacl = se_sess->se_node_acl;
 344        if (se_nacl) {
 345                spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 346                if (se_nacl->acl_stop == 0)
 347                        list_del(&se_sess->sess_acl_list);
 348                /*
 349                 * If the session list is empty, then clear the pointer.
 350                 * Otherwise, set the struct se_session pointer from the tail
 351                 * element of the per struct se_node_acl active session list.
 352                 */
 353                if (list_empty(&se_nacl->acl_sess_list))
 354                        se_nacl->nacl_sess = NULL;
 355                else {
 356                        se_nacl->nacl_sess = container_of(
 357                                        se_nacl->acl_sess_list.prev,
 358                                        struct se_session, sess_acl_list);
 359                }
 360                spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 361        }
 362}
 363EXPORT_SYMBOL(transport_deregister_session_configfs);
 364
 365void transport_free_session(struct se_session *se_sess)
 366{
 367        kmem_cache_free(se_sess_cache, se_sess);
 368}
 369EXPORT_SYMBOL(transport_free_session);
 370
 371void transport_deregister_session(struct se_session *se_sess)
 372{
 373        struct se_portal_group *se_tpg = se_sess->se_tpg;
 374        struct target_core_fabric_ops *se_tfo;
 375        struct se_node_acl *se_nacl;
 376        unsigned long flags;
 377        bool comp_nacl = true;
 378
 379        if (!se_tpg) {
 380                transport_free_session(se_sess);
 381                return;
 382        }
 383        se_tfo = se_tpg->se_tpg_tfo;
 384
 385        spin_lock_irqsave(&se_tpg->session_lock, flags);
 386        list_del(&se_sess->sess_list);
 387        se_sess->se_tpg = NULL;
 388        se_sess->fabric_sess_ptr = NULL;
 389        spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 390
 391        /*
 392         * Determine if we need to do extra work for this initiator node's
 393         * struct se_node_acl if it had been previously dynamically generated.
 394         */
 395        se_nacl = se_sess->se_node_acl;
 396
 397        spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
 398        if (se_nacl && se_nacl->dynamic_node_acl) {
 399                if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 400                        list_del(&se_nacl->acl_list);
 401                        se_tpg->num_node_acls--;
 402                        spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
 403                        core_tpg_wait_for_nacl_pr_ref(se_nacl);
 404                        core_free_device_list_for_node(se_nacl, se_tpg);
 405                        se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
 406
 407                        comp_nacl = false;
 408                        spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
 409                }
 410        }
 411        spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
 412
 413        pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 414                se_tpg->se_tpg_tfo->get_fabric_name());
 415        /*
 416         * If last kref is dropping now for an explict NodeACL, awake sleeping
 417         * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 418         * removal context.
 419         */
 420        if (se_nacl && comp_nacl == true)
 421                target_put_nacl(se_nacl);
 422
 423        transport_free_session(se_sess);
 424}
 425EXPORT_SYMBOL(transport_deregister_session);
 426
 427/*
 428 * Called with cmd->t_state_lock held.
 429 */
 430static void target_remove_from_state_list(struct se_cmd *cmd)
 431{
 432        struct se_device *dev = cmd->se_dev;
 433        unsigned long flags;
 434
 435        if (!dev)
 436                return;
 437
 438        if (cmd->transport_state & CMD_T_BUSY)
 439                return;
 440
 441        spin_lock_irqsave(&dev->execute_task_lock, flags);
 442        if (cmd->state_active) {
 443                list_del(&cmd->state_list);
 444                cmd->state_active = false;
 445        }
 446        spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 447}
 448
 449static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists)
 450{
 451        unsigned long flags;
 452
 453        spin_lock_irqsave(&cmd->t_state_lock, flags);
 454        /*
 455         * Determine if IOCTL context caller in requesting the stopping of this
 456         * command for LUN shutdown purposes.
 457         */
 458        if (cmd->transport_state & CMD_T_LUN_STOP) {
 459                pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
 460                        __func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
 461
 462                cmd->transport_state &= ~CMD_T_ACTIVE;
 463                if (remove_from_lists)
 464                        target_remove_from_state_list(cmd);
 465                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 466
 467                complete(&cmd->transport_lun_stop_comp);
 468                return 1;
 469        }
 470
 471        if (remove_from_lists) {
 472                target_remove_from_state_list(cmd);
 473
 474                /*
 475                 * Clear struct se_cmd->se_lun before the handoff to FE.
 476                 */
 477                cmd->se_lun = NULL;
 478        }
 479
 480        /*
 481         * Determine if frontend context caller is requesting the stopping of
 482         * this command for frontend exceptions.
 483         */
 484        if (cmd->transport_state & CMD_T_STOP) {
 485                pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
 486                        __func__, __LINE__,
 487                        cmd->se_tfo->get_task_tag(cmd));
 488
 489                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 490
 491                complete(&cmd->t_transport_stop_comp);
 492                return 1;
 493        }
 494
 495        cmd->transport_state &= ~CMD_T_ACTIVE;
 496        if (remove_from_lists) {
 497                /*
 498                 * Some fabric modules like tcm_loop can release
 499                 * their internally allocated I/O reference now and
 500                 * struct se_cmd now.
 501                 *
 502                 * Fabric modules are expected to return '1' here if the
 503                 * se_cmd being passed is released at this point,
 504                 * or zero if not being released.
 505                 */
 506                if (cmd->se_tfo->check_stop_free != NULL) {
 507                        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 508                        return cmd->se_tfo->check_stop_free(cmd);
 509                }
 510        }
 511
 512        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 513        return 0;
 514}
 515
 516static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 517{
 518        return transport_cmd_check_stop(cmd, true);
 519}
 520
 521static void transport_lun_remove_cmd(struct se_cmd *cmd)
 522{
 523        struct se_lun *lun = cmd->se_lun;
 524        unsigned long flags;
 525
 526        if (!lun)
 527                return;
 528
 529        spin_lock_irqsave(&cmd->t_state_lock, flags);
 530        if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
 531                cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
 532                target_remove_from_state_list(cmd);
 533        }
 534        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 535
 536        spin_lock_irqsave(&lun->lun_cmd_lock, flags);
 537        if (!list_empty(&cmd->se_lun_node))
 538                list_del_init(&cmd->se_lun_node);
 539        spin_unlock_irqrestore(&lun->lun_cmd_lock, flags);
 540}
 541
 542void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 543{
 544        if (transport_cmd_check_stop_to_fabric(cmd))
 545                return;
 546        if (remove)
 547                transport_put_cmd(cmd);
 548}
 549
 550static void target_complete_failure_work(struct work_struct *work)
 551{
 552        struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 553
 554        transport_generic_request_failure(cmd,
 555                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 556}
 557
 558/*
 559 * Used when asking transport to copy Sense Data from the underlying
 560 * Linux/SCSI struct scsi_cmnd
 561 */
 562static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 563{
 564        struct se_device *dev = cmd->se_dev;
 565
 566        WARN_ON(!cmd->se_lun);
 567
 568        if (!dev)
 569                return NULL;
 570
 571        if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 572                return NULL;
 573
 574        cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 575
 576        pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 577                dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 578        return cmd->sense_buffer;
 579}
 580
 581void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 582{
 583        struct se_device *dev = cmd->se_dev;
 584        int success = scsi_status == GOOD;
 585        unsigned long flags;
 586
 587        cmd->scsi_status = scsi_status;
 588
 589
 590        spin_lock_irqsave(&cmd->t_state_lock, flags);
 591        cmd->transport_state &= ~CMD_T_BUSY;
 592
 593        if (dev && dev->transport->transport_complete) {
 594                dev->transport->transport_complete(cmd,
 595                                cmd->t_data_sg,
 596                                transport_get_sense_buffer(cmd));
 597                if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 598                        success = 1;
 599        }
 600
 601        /*
 602         * See if we are waiting to complete for an exception condition.
 603         */
 604        if (cmd->transport_state & CMD_T_REQUEST_STOP) {
 605                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 606                complete(&cmd->task_stop_comp);
 607                return;
 608        }
 609
 610        if (!success)
 611                cmd->transport_state |= CMD_T_FAILED;
 612
 613        /*
 614         * Check for case where an explict ABORT_TASK has been received
 615         * and transport_wait_for_tasks() will be waiting for completion..
 616         */
 617        if (cmd->transport_state & CMD_T_ABORTED &&
 618            cmd->transport_state & CMD_T_STOP) {
 619                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 620                complete(&cmd->t_transport_stop_comp);
 621                return;
 622        } else if (cmd->transport_state & CMD_T_FAILED) {
 623                INIT_WORK(&cmd->work, target_complete_failure_work);
 624        } else {
 625                INIT_WORK(&cmd->work, target_complete_ok_work);
 626        }
 627
 628        cmd->t_state = TRANSPORT_COMPLETE;
 629        cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 630        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 631
 632        queue_work(target_completion_wq, &cmd->work);
 633}
 634EXPORT_SYMBOL(target_complete_cmd);
 635
 636static void target_add_to_state_list(struct se_cmd *cmd)
 637{
 638        struct se_device *dev = cmd->se_dev;
 639        unsigned long flags;
 640
 641        spin_lock_irqsave(&dev->execute_task_lock, flags);
 642        if (!cmd->state_active) {
 643                list_add_tail(&cmd->state_list, &dev->state_list);
 644                cmd->state_active = true;
 645        }
 646        spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 647}
 648
 649/*
 650 * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 651 */
 652static void transport_write_pending_qf(struct se_cmd *cmd);
 653static void transport_complete_qf(struct se_cmd *cmd);
 654
 655void target_qf_do_work(struct work_struct *work)
 656{
 657        struct se_device *dev = container_of(work, struct se_device,
 658                                        qf_work_queue);
 659        LIST_HEAD(qf_cmd_list);
 660        struct se_cmd *cmd, *cmd_tmp;
 661
 662        spin_lock_irq(&dev->qf_cmd_lock);
 663        list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 664        spin_unlock_irq(&dev->qf_cmd_lock);
 665
 666        list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 667                list_del(&cmd->se_qf_node);
 668                atomic_dec(&dev->dev_qf_count);
 669                smp_mb__after_atomic_dec();
 670
 671                pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 672                        " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 673                        (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 674                        (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 675                        : "UNKNOWN");
 676
 677                if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 678                        transport_write_pending_qf(cmd);
 679                else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 680                        transport_complete_qf(cmd);
 681        }
 682}
 683
 684unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 685{
 686        switch (cmd->data_direction) {
 687        case DMA_NONE:
 688                return "NONE";
 689        case DMA_FROM_DEVICE:
 690                return "READ";
 691        case DMA_TO_DEVICE:
 692                return "WRITE";
 693        case DMA_BIDIRECTIONAL:
 694                return "BIDI";
 695        default:
 696                break;
 697        }
 698
 699        return "UNKNOWN";
 700}
 701
 702void transport_dump_dev_state(
 703        struct se_device *dev,
 704        char *b,
 705        int *bl)
 706{
 707        *bl += sprintf(b + *bl, "Status: ");
 708        if (dev->export_count)
 709                *bl += sprintf(b + *bl, "ACTIVATED");
 710        else
 711                *bl += sprintf(b + *bl, "DEACTIVATED");
 712
 713        *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 714        *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 715                dev->dev_attrib.block_size,
 716                dev->dev_attrib.hw_max_sectors);
 717        *bl += sprintf(b + *bl, "        ");
 718}
 719
 720void transport_dump_vpd_proto_id(
 721        struct t10_vpd *vpd,
 722        unsigned char *p_buf,
 723        int p_buf_len)
 724{
 725        unsigned char buf[VPD_TMP_BUF_SIZE];
 726        int len;
 727
 728        memset(buf, 0, VPD_TMP_BUF_SIZE);
 729        len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 730
 731        switch (vpd->protocol_identifier) {
 732        case 0x00:
 733                sprintf(buf+len, "Fibre Channel\n");
 734                break;
 735        case 0x10:
 736                sprintf(buf+len, "Parallel SCSI\n");
 737                break;
 738        case 0x20:
 739                sprintf(buf+len, "SSA\n");
 740                break;
 741        case 0x30:
 742                sprintf(buf+len, "IEEE 1394\n");
 743                break;
 744        case 0x40:
 745                sprintf(buf+len, "SCSI Remote Direct Memory Access"
 746                                " Protocol\n");
 747                break;
 748        case 0x50:
 749                sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 750                break;
 751        case 0x60:
 752                sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 753                break;
 754        case 0x70:
 755                sprintf(buf+len, "Automation/Drive Interface Transport"
 756                                " Protocol\n");
 757                break;
 758        case 0x80:
 759                sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 760                break;
 761        default:
 762                sprintf(buf+len, "Unknown 0x%02x\n",
 763                                vpd->protocol_identifier);
 764                break;
 765        }
 766
 767        if (p_buf)
 768                strncpy(p_buf, buf, p_buf_len);
 769        else
 770                pr_debug("%s", buf);
 771}
 772
 773void
 774transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 775{
 776        /*
 777         * Check if the Protocol Identifier Valid (PIV) bit is set..
 778         *
 779         * from spc3r23.pdf section 7.5.1
 780         */
 781         if (page_83[1] & 0x80) {
 782                vpd->protocol_identifier = (page_83[0] & 0xf0);
 783                vpd->protocol_identifier_set = 1;
 784                transport_dump_vpd_proto_id(vpd, NULL, 0);
 785        }
 786}
 787EXPORT_SYMBOL(transport_set_vpd_proto_id);
 788
 789int transport_dump_vpd_assoc(
 790        struct t10_vpd *vpd,
 791        unsigned char *p_buf,
 792        int p_buf_len)
 793{
 794        unsigned char buf[VPD_TMP_BUF_SIZE];
 795        int ret = 0;
 796        int len;
 797
 798        memset(buf, 0, VPD_TMP_BUF_SIZE);
 799        len = sprintf(buf, "T10 VPD Identifier Association: ");
 800
 801        switch (vpd->association) {
 802        case 0x00:
 803                sprintf(buf+len, "addressed logical unit\n");
 804                break;
 805        case 0x10:
 806                sprintf(buf+len, "target port\n");
 807                break;
 808        case 0x20:
 809                sprintf(buf+len, "SCSI target device\n");
 810                break;
 811        default:
 812                sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 813                ret = -EINVAL;
 814                break;
 815        }
 816
 817        if (p_buf)
 818                strncpy(p_buf, buf, p_buf_len);
 819        else
 820                pr_debug("%s", buf);
 821
 822        return ret;
 823}
 824
 825int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 826{
 827        /*
 828         * The VPD identification association..
 829         *
 830         * from spc3r23.pdf Section 7.6.3.1 Table 297
 831         */
 832        vpd->association = (page_83[1] & 0x30);
 833        return transport_dump_vpd_assoc(vpd, NULL, 0);
 834}
 835EXPORT_SYMBOL(transport_set_vpd_assoc);
 836
 837int transport_dump_vpd_ident_type(
 838        struct t10_vpd *vpd,
 839        unsigned char *p_buf,
 840        int p_buf_len)
 841{
 842        unsigned char buf[VPD_TMP_BUF_SIZE];
 843        int ret = 0;
 844        int len;
 845
 846        memset(buf, 0, VPD_TMP_BUF_SIZE);
 847        len = sprintf(buf, "T10 VPD Identifier Type: ");
 848
 849        switch (vpd->device_identifier_type) {
 850        case 0x00:
 851                sprintf(buf+len, "Vendor specific\n");
 852                break;
 853        case 0x01:
 854                sprintf(buf+len, "T10 Vendor ID based\n");
 855                break;
 856        case 0x02:
 857                sprintf(buf+len, "EUI-64 based\n");
 858                break;
 859        case 0x03:
 860                sprintf(buf+len, "NAA\n");
 861                break;
 862        case 0x04:
 863                sprintf(buf+len, "Relative target port identifier\n");
 864                break;
 865        case 0x08:
 866                sprintf(buf+len, "SCSI name string\n");
 867                break;
 868        default:
 869                sprintf(buf+len, "Unsupported: 0x%02x\n",
 870                                vpd->device_identifier_type);
 871                ret = -EINVAL;
 872                break;
 873        }
 874
 875        if (p_buf) {
 876                if (p_buf_len < strlen(buf)+1)
 877                        return -EINVAL;
 878                strncpy(p_buf, buf, p_buf_len);
 879        } else {
 880                pr_debug("%s", buf);
 881        }
 882
 883        return ret;
 884}
 885
 886int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
 887{
 888        /*
 889         * The VPD identifier type..
 890         *
 891         * from spc3r23.pdf Section 7.6.3.1 Table 298
 892         */
 893        vpd->device_identifier_type = (page_83[1] & 0x0f);
 894        return transport_dump_vpd_ident_type(vpd, NULL, 0);
 895}
 896EXPORT_SYMBOL(transport_set_vpd_ident_type);
 897
 898int transport_dump_vpd_ident(
 899        struct t10_vpd *vpd,
 900        unsigned char *p_buf,
 901        int p_buf_len)
 902{
 903        unsigned char buf[VPD_TMP_BUF_SIZE];
 904        int ret = 0;
 905
 906        memset(buf, 0, VPD_TMP_BUF_SIZE);
 907
 908        switch (vpd->device_identifier_code_set) {
 909        case 0x01: /* Binary */
 910                sprintf(buf, "T10 VPD Binary Device Identifier: %s\n",
 911                        &vpd->device_identifier[0]);
 912                break;
 913        case 0x02: /* ASCII */
 914                sprintf(buf, "T10 VPD ASCII Device Identifier: %s\n",
 915                        &vpd->device_identifier[0]);
 916                break;
 917        case 0x03: /* UTF-8 */
 918                sprintf(buf, "T10 VPD UTF-8 Device Identifier: %s\n",
 919                        &vpd->device_identifier[0]);
 920                break;
 921        default:
 922                sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
 923                        " 0x%02x", vpd->device_identifier_code_set);
 924                ret = -EINVAL;
 925                break;
 926        }
 927
 928        if (p_buf)
 929                strncpy(p_buf, buf, p_buf_len);
 930        else
 931                pr_debug("%s", buf);
 932
 933        return ret;
 934}
 935
 936int
 937transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
 938{
 939        static const char hex_str[] = "0123456789abcdef";
 940        int j = 0, i = 4; /* offset to start of the identifier */
 941
 942        /*
 943         * The VPD Code Set (encoding)
 944         *
 945         * from spc3r23.pdf Section 7.6.3.1 Table 296
 946         */
 947        vpd->device_identifier_code_set = (page_83[0] & 0x0f);
 948        switch (vpd->device_identifier_code_set) {
 949        case 0x01: /* Binary */
 950                vpd->device_identifier[j++] =
 951                                hex_str[vpd->device_identifier_type];
 952                while (i < (4 + page_83[3])) {
 953                        vpd->device_identifier[j++] =
 954                                hex_str[(page_83[i] & 0xf0) >> 4];
 955                        vpd->device_identifier[j++] =
 956                                hex_str[page_83[i] & 0x0f];
 957                        i++;
 958                }
 959                break;
 960        case 0x02: /* ASCII */
 961        case 0x03: /* UTF-8 */
 962                while (i < (4 + page_83[3]))
 963                        vpd->device_identifier[j++] = page_83[i++];
 964                break;
 965        default:
 966                break;
 967        }
 968
 969        return transport_dump_vpd_ident(vpd, NULL, 0);
 970}
 971EXPORT_SYMBOL(transport_set_vpd_ident);
 972
 973sense_reason_t
 974target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
 975{
 976        struct se_device *dev = cmd->se_dev;
 977
 978        if (cmd->unknown_data_length) {
 979                cmd->data_length = size;
 980        } else if (size != cmd->data_length) {
 981                pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
 982                        " %u does not match SCSI CDB Length: %u for SAM Opcode:"
 983                        " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
 984                                cmd->data_length, size, cmd->t_task_cdb[0]);
 985
 986                if (cmd->data_direction == DMA_TO_DEVICE) {
 987                        pr_err("Rejecting underflow/overflow"
 988                                        " WRITE data\n");
 989                        return TCM_INVALID_CDB_FIELD;
 990                }
 991                /*
 992                 * Reject READ_* or WRITE_* with overflow/underflow for
 993                 * type SCF_SCSI_DATA_CDB.
 994                 */
 995                if (dev->dev_attrib.block_size != 512)  {
 996                        pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
 997                                " CDB on non 512-byte sector setup subsystem"
 998                                " plugin: %s\n", dev->transport->name);
 999                        /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1000                        return TCM_INVALID_CDB_FIELD;
1001                }
1002                /*
1003                 * For the overflow case keep the existing fabric provided
1004                 * ->data_length.  Otherwise for the underflow case, reset
1005                 * ->data_length to the smaller SCSI expected data transfer
1006                 * length.
1007                 */
1008                if (size > cmd->data_length) {
1009                        cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1010                        cmd->residual_count = (size - cmd->data_length);
1011                } else {
1012                        cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1013                        cmd->residual_count = (cmd->data_length - size);
1014                        cmd->data_length = size;
1015                }
1016        }
1017
1018        return 0;
1019
1020}
1021
1022/*
1023 * Used by fabric modules containing a local struct se_cmd within their
1024 * fabric dependent per I/O descriptor.
1025 */
1026void transport_init_se_cmd(
1027        struct se_cmd *cmd,
1028        struct target_core_fabric_ops *tfo,
1029        struct se_session *se_sess,
1030        u32 data_length,
1031        int data_direction,
1032        int task_attr,
1033        unsigned char *sense_buffer)
1034{
1035        INIT_LIST_HEAD(&cmd->se_lun_node);
1036        INIT_LIST_HEAD(&cmd->se_delayed_node);
1037        INIT_LIST_HEAD(&cmd->se_qf_node);
1038        INIT_LIST_HEAD(&cmd->se_cmd_list);
1039        INIT_LIST_HEAD(&cmd->state_list);
1040        init_completion(&cmd->transport_lun_fe_stop_comp);
1041        init_completion(&cmd->transport_lun_stop_comp);
1042        init_completion(&cmd->t_transport_stop_comp);
1043        init_completion(&cmd->cmd_wait_comp);
1044        init_completion(&cmd->task_stop_comp);
1045        spin_lock_init(&cmd->t_state_lock);
1046        cmd->transport_state = CMD_T_DEV_ACTIVE;
1047
1048        cmd->se_tfo = tfo;
1049        cmd->se_sess = se_sess;
1050        cmd->data_length = data_length;
1051        cmd->data_direction = data_direction;
1052        cmd->sam_task_attr = task_attr;
1053        cmd->sense_buffer = sense_buffer;
1054
1055        cmd->state_active = false;
1056}
1057EXPORT_SYMBOL(transport_init_se_cmd);
1058
1059static sense_reason_t
1060transport_check_alloc_task_attr(struct se_cmd *cmd)
1061{
1062        struct se_device *dev = cmd->se_dev;
1063
1064        /*
1065         * Check if SAM Task Attribute emulation is enabled for this
1066         * struct se_device storage object
1067         */
1068        if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1069                return 0;
1070
1071        if (cmd->sam_task_attr == MSG_ACA_TAG) {
1072                pr_debug("SAM Task Attribute ACA"
1073                        " emulation is not supported\n");
1074                return TCM_INVALID_CDB_FIELD;
1075        }
1076        /*
1077         * Used to determine when ORDERED commands should go from
1078         * Dormant to Active status.
1079         */
1080        cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1081        smp_mb__after_atomic_inc();
1082        pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1083                        cmd->se_ordered_id, cmd->sam_task_attr,
1084                        dev->transport->name);
1085        return 0;
1086}
1087
1088sense_reason_t
1089target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1090{
1091        struct se_device *dev = cmd->se_dev;
1092        unsigned long flags;
1093        sense_reason_t ret;
1094
1095        /*
1096         * Ensure that the received CDB is less than the max (252 + 8) bytes
1097         * for VARIABLE_LENGTH_CMD
1098         */
1099        if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1100                pr_err("Received SCSI CDB with command_size: %d that"
1101                        " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1102                        scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1103                return TCM_INVALID_CDB_FIELD;
1104        }
1105        /*
1106         * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1107         * allocate the additional extended CDB buffer now..  Otherwise
1108         * setup the pointer from __t_task_cdb to t_task_cdb.
1109         */
1110        if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1111                cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1112                                                GFP_KERNEL);
1113                if (!cmd->t_task_cdb) {
1114                        pr_err("Unable to allocate cmd->t_task_cdb"
1115                                " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1116                                scsi_command_size(cdb),
1117                                (unsigned long)sizeof(cmd->__t_task_cdb));
1118                        return TCM_OUT_OF_RESOURCES;
1119                }
1120        } else
1121                cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1122        /*
1123         * Copy the original CDB into cmd->
1124         */
1125        memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1126
1127        /*
1128         * Check for an existing UNIT ATTENTION condition
1129         */
1130        ret = target_scsi3_ua_check(cmd);
1131        if (ret)
1132                return ret;
1133
1134        ret = target_alua_state_check(cmd);
1135        if (ret)
1136                return ret;
1137
1138        ret = target_check_reservation(cmd);
1139        if (ret)
1140                return ret;
1141
1142        ret = dev->transport->parse_cdb(cmd);
1143        if (ret)
1144                return ret;
1145
1146        ret = transport_check_alloc_task_attr(cmd);
1147        if (ret)
1148                return ret;
1149
1150        spin_lock_irqsave(&cmd->t_state_lock, flags);
1151        cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1152        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1153
1154        spin_lock(&cmd->se_lun->lun_sep_lock);
1155        if (cmd->se_lun->lun_sep)
1156                cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1157        spin_unlock(&cmd->se_lun->lun_sep_lock);
1158        return 0;
1159}
1160EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1161
1162/*
1163 * Used by fabric module frontends to queue tasks directly.
1164 * Many only be used from process context only
1165 */
1166int transport_handle_cdb_direct(
1167        struct se_cmd *cmd)
1168{
1169        sense_reason_t ret;
1170
1171        if (!cmd->se_lun) {
1172                dump_stack();
1173                pr_err("cmd->se_lun is NULL\n");
1174                return -EINVAL;
1175        }
1176        if (in_interrupt()) {
1177                dump_stack();
1178                pr_err("transport_generic_handle_cdb cannot be called"
1179                                " from interrupt context\n");
1180                return -EINVAL;
1181        }
1182        /*
1183         * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1184         * outstanding descriptors are handled correctly during shutdown via
1185         * transport_wait_for_tasks()
1186         *
1187         * Also, we don't take cmd->t_state_lock here as we only expect
1188         * this to be called for initial descriptor submission.
1189         */
1190        cmd->t_state = TRANSPORT_NEW_CMD;
1191        cmd->transport_state |= CMD_T_ACTIVE;
1192
1193        /*
1194         * transport_generic_new_cmd() is already handling QUEUE_FULL,
1195         * so follow TRANSPORT_NEW_CMD processing thread context usage
1196         * and call transport_generic_request_failure() if necessary..
1197         */
1198        ret = transport_generic_new_cmd(cmd);
1199        if (ret)
1200                transport_generic_request_failure(cmd, ret);
1201        return 0;
1202}
1203EXPORT_SYMBOL(transport_handle_cdb_direct);
1204
1205static sense_reason_t
1206transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1207                u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1208{
1209        if (!sgl || !sgl_count)
1210                return 0;
1211
1212        /*
1213         * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1214         * scatterlists already have been set to follow what the fabric
1215         * passes for the original expected data transfer length.
1216         */
1217        if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1218                pr_warn("Rejecting SCSI DATA overflow for fabric using"
1219                        " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1220                return TCM_INVALID_CDB_FIELD;
1221        }
1222
1223        cmd->t_data_sg = sgl;
1224        cmd->t_data_nents = sgl_count;
1225
1226        if (sgl_bidi && sgl_bidi_count) {
1227                cmd->t_bidi_data_sg = sgl_bidi;
1228                cmd->t_bidi_data_nents = sgl_bidi_count;
1229        }
1230        cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1231        return 0;
1232}
1233
1234/*
1235 * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1236 *                       se_cmd + use pre-allocated SGL memory.
1237 *
1238 * @se_cmd: command descriptor to submit
1239 * @se_sess: associated se_sess for endpoint
1240 * @cdb: pointer to SCSI CDB
1241 * @sense: pointer to SCSI sense buffer
1242 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1243 * @data_length: fabric expected data transfer length
1244 * @task_addr: SAM task attribute
1245 * @data_dir: DMA data direction
1246 * @flags: flags for command submission from target_sc_flags_tables
1247 * @sgl: struct scatterlist memory for unidirectional mapping
1248 * @sgl_count: scatterlist count for unidirectional mapping
1249 * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1250 * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1251 *
1252 * Returns non zero to signal active I/O shutdown failure.  All other
1253 * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1254 * but still return zero here.
1255 *
1256 * This may only be called from process context, and also currently
1257 * assumes internal allocation of fabric payload buffer by target-core.
1258 */
1259int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1260                unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1261                u32 data_length, int task_attr, int data_dir, int flags,
1262                struct scatterlist *sgl, u32 sgl_count,
1263                struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1264{
1265        struct se_portal_group *se_tpg;
1266        sense_reason_t rc;
1267        int ret;
1268
1269        se_tpg = se_sess->se_tpg;
1270        BUG_ON(!se_tpg);
1271        BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1272        BUG_ON(in_interrupt());
1273        /*
1274         * Initialize se_cmd for target operation.  From this point
1275         * exceptions are handled by sending exception status via
1276         * target_core_fabric_ops->queue_status() callback
1277         */
1278        transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1279                                data_length, data_dir, task_attr, sense);
1280        if (flags & TARGET_SCF_UNKNOWN_SIZE)
1281                se_cmd->unknown_data_length = 1;
1282        /*
1283         * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1284         * se_sess->sess_cmd_list.  A second kref_get here is necessary
1285         * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1286         * kref_put() to happen during fabric packet acknowledgement.
1287         */
1288        ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1289        if (ret)
1290                return ret;
1291        /*
1292         * Signal bidirectional data payloads to target-core
1293         */
1294        if (flags & TARGET_SCF_BIDI_OP)
1295                se_cmd->se_cmd_flags |= SCF_BIDI;
1296        /*
1297         * Locate se_lun pointer and attach it to struct se_cmd
1298         */
1299        rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1300        if (rc) {
1301                transport_send_check_condition_and_sense(se_cmd, rc, 0);
1302                target_put_sess_cmd(se_sess, se_cmd);
1303                return 0;
1304        }
1305
1306        rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1307        if (rc != 0) {
1308                transport_generic_request_failure(se_cmd, rc);
1309                return 0;
1310        }
1311        /*
1312         * When a non zero sgl_count has been passed perform SGL passthrough
1313         * mapping for pre-allocated fabric memory instead of having target
1314         * core perform an internal SGL allocation..
1315         */
1316        if (sgl_count != 0) {
1317                BUG_ON(!sgl);
1318
1319                /*
1320                 * A work-around for tcm_loop as some userspace code via
1321                 * scsi-generic do not memset their associated read buffers,
1322                 * so go ahead and do that here for type non-data CDBs.  Also
1323                 * note that this is currently guaranteed to be a single SGL
1324                 * for this case by target core in target_setup_cmd_from_cdb()
1325                 * -> transport_generic_cmd_sequencer().
1326                 */
1327                if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1328                     se_cmd->data_direction == DMA_FROM_DEVICE) {
1329                        unsigned char *buf = NULL;
1330
1331                        if (sgl)
1332                                buf = kmap(sg_page(sgl)) + sgl->offset;
1333
1334                        if (buf) {
1335                                memset(buf, 0, sgl->length);
1336                                kunmap(sg_page(sgl));
1337                        }
1338                }
1339
1340                rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1341                                sgl_bidi, sgl_bidi_count);
1342                if (rc != 0) {
1343                        transport_generic_request_failure(se_cmd, rc);
1344                        return 0;
1345                }
1346        }
1347        /*
1348         * Check if we need to delay processing because of ALUA
1349         * Active/NonOptimized primary access state..
1350         */
1351        core_alua_check_nonop_delay(se_cmd);
1352
1353        transport_handle_cdb_direct(se_cmd);
1354        return 0;
1355}
1356EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1357
1358/*
1359 * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1360 *
1361 * @se_cmd: command descriptor to submit
1362 * @se_sess: associated se_sess for endpoint
1363 * @cdb: pointer to SCSI CDB
1364 * @sense: pointer to SCSI sense buffer
1365 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1366 * @data_length: fabric expected data transfer length
1367 * @task_addr: SAM task attribute
1368 * @data_dir: DMA data direction
1369 * @flags: flags for command submission from target_sc_flags_tables
1370 *
1371 * Returns non zero to signal active I/O shutdown failure.  All other
1372 * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1373 * but still return zero here.
1374 *
1375 * This may only be called from process context, and also currently
1376 * assumes internal allocation of fabric payload buffer by target-core.
1377 *
1378 * It also assumes interal target core SGL memory allocation.
1379 */
1380int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1381                unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1382                u32 data_length, int task_attr, int data_dir, int flags)
1383{
1384        return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1385                        unpacked_lun, data_length, task_attr, data_dir,
1386                        flags, NULL, 0, NULL, 0);
1387}
1388EXPORT_SYMBOL(target_submit_cmd);
1389
1390static void target_complete_tmr_failure(struct work_struct *work)
1391{
1392        struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1393
1394        se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1395        se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1396
1397        transport_cmd_check_stop_to_fabric(se_cmd);
1398}
1399
1400/**
1401 * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1402 *                     for TMR CDBs
1403 *
1404 * @se_cmd: command descriptor to submit
1405 * @se_sess: associated se_sess for endpoint
1406 * @sense: pointer to SCSI sense buffer
1407 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1408 * @fabric_context: fabric context for TMR req
1409 * @tm_type: Type of TM request
1410 * @gfp: gfp type for caller
1411 * @tag: referenced task tag for TMR_ABORT_TASK
1412 * @flags: submit cmd flags
1413 *
1414 * Callable from all contexts.
1415 **/
1416
1417int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1418                unsigned char *sense, u32 unpacked_lun,
1419                void *fabric_tmr_ptr, unsigned char tm_type,
1420                gfp_t gfp, unsigned int tag, int flags)
1421{
1422        struct se_portal_group *se_tpg;
1423        int ret;
1424
1425        se_tpg = se_sess->se_tpg;
1426        BUG_ON(!se_tpg);
1427
1428        transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1429                              0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1430        /*
1431         * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1432         * allocation failure.
1433         */
1434        ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1435        if (ret < 0)
1436                return -ENOMEM;
1437
1438        if (tm_type == TMR_ABORT_TASK)
1439                se_cmd->se_tmr_req->ref_task_tag = tag;
1440
1441        /* See target_submit_cmd for commentary */
1442        ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1443        if (ret) {
1444                core_tmr_release_req(se_cmd->se_tmr_req);
1445                return ret;
1446        }
1447
1448        ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1449        if (ret) {
1450                /*
1451                 * For callback during failure handling, push this work off
1452                 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1453                 */
1454                INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1455                schedule_work(&se_cmd->work);
1456                return 0;
1457        }
1458        transport_generic_handle_tmr(se_cmd);
1459        return 0;
1460}
1461EXPORT_SYMBOL(target_submit_tmr);
1462
1463/*
1464 * If the cmd is active, request it to be stopped and sleep until it
1465 * has completed.
1466 */
1467bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1468{
1469        bool was_active = false;
1470
1471        if (cmd->transport_state & CMD_T_BUSY) {
1472                cmd->transport_state |= CMD_T_REQUEST_STOP;
1473                spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1474
1475                pr_debug("cmd %p waiting to complete\n", cmd);
1476                wait_for_completion(&cmd->task_stop_comp);
1477                pr_debug("cmd %p stopped successfully\n", cmd);
1478
1479                spin_lock_irqsave(&cmd->t_state_lock, *flags);
1480                cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1481                cmd->transport_state &= ~CMD_T_BUSY;
1482                was_active = true;
1483        }
1484
1485        return was_active;
1486}
1487
1488/*
1489 * Handle SAM-esque emulation for generic transport request failures.
1490 */
1491void transport_generic_request_failure(struct se_cmd *cmd,
1492                sense_reason_t sense_reason)
1493{
1494        int ret = 0;
1495
1496        pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1497                " CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1498                cmd->t_task_cdb[0]);
1499        pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1500                cmd->se_tfo->get_cmd_state(cmd),
1501                cmd->t_state, sense_reason);
1502        pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1503                (cmd->transport_state & CMD_T_ACTIVE) != 0,
1504                (cmd->transport_state & CMD_T_STOP) != 0,
1505                (cmd->transport_state & CMD_T_SENT) != 0);
1506
1507        /*
1508         * For SAM Task Attribute emulation for failed struct se_cmd
1509         */
1510        transport_complete_task_attr(cmd);
1511
1512        switch (sense_reason) {
1513        case TCM_NON_EXISTENT_LUN:
1514        case TCM_UNSUPPORTED_SCSI_OPCODE:
1515        case TCM_INVALID_CDB_FIELD:
1516        case TCM_INVALID_PARAMETER_LIST:
1517        case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1518        case TCM_UNKNOWN_MODE_PAGE:
1519        case TCM_WRITE_PROTECTED:
1520        case TCM_ADDRESS_OUT_OF_RANGE:
1521        case TCM_CHECK_CONDITION_ABORT_CMD:
1522        case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1523        case TCM_CHECK_CONDITION_NOT_READY:
1524                break;
1525        case TCM_OUT_OF_RESOURCES:
1526                sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1527                break;
1528        case TCM_RESERVATION_CONFLICT:
1529                /*
1530                 * No SENSE Data payload for this case, set SCSI Status
1531                 * and queue the response to $FABRIC_MOD.
1532                 *
1533                 * Uses linux/include/scsi/scsi.h SAM status codes defs
1534                 */
1535                cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1536                /*
1537                 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1538                 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1539                 * CONFLICT STATUS.
1540                 *
1541                 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1542                 */
1543                if (cmd->se_sess &&
1544                    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1545                        core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1546                                cmd->orig_fe_lun, 0x2C,
1547                                ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1548
1549                ret = cmd->se_tfo->queue_status(cmd);
1550                if (ret == -EAGAIN || ret == -ENOMEM)
1551                        goto queue_full;
1552                goto check_stop;
1553        default:
1554                pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1555                        cmd->t_task_cdb[0], sense_reason);
1556                sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1557                break;
1558        }
1559
1560        ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1561        if (ret == -EAGAIN || ret == -ENOMEM)
1562                goto queue_full;
1563
1564check_stop:
1565        transport_lun_remove_cmd(cmd);
1566        if (!transport_cmd_check_stop_to_fabric(cmd))
1567                ;
1568        return;
1569
1570queue_full:
1571        cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1572        transport_handle_queue_full(cmd, cmd->se_dev);
1573}
1574EXPORT_SYMBOL(transport_generic_request_failure);
1575
1576static void __target_execute_cmd(struct se_cmd *cmd)
1577{
1578        sense_reason_t ret;
1579
1580        spin_lock_irq(&cmd->t_state_lock);
1581        cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
1582        spin_unlock_irq(&cmd->t_state_lock);
1583
1584        if (cmd->execute_cmd) {
1585                ret = cmd->execute_cmd(cmd);
1586                if (ret) {
1587                        spin_lock_irq(&cmd->t_state_lock);
1588                        cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1589                        spin_unlock_irq(&cmd->t_state_lock);
1590
1591                        transport_generic_request_failure(cmd, ret);
1592                }
1593        }
1594}
1595
1596static bool target_handle_task_attr(struct se_cmd *cmd)
1597{
1598        struct se_device *dev = cmd->se_dev;
1599
1600        if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1601                return false;
1602
1603        /*
1604         * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1605         * to allow the passed struct se_cmd list of tasks to the front of the list.
1606         */
1607        switch (cmd->sam_task_attr) {
1608        case MSG_HEAD_TAG:
1609                pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1610                         "se_ordered_id: %u\n",
1611                         cmd->t_task_cdb[0], cmd->se_ordered_id);
1612                return false;
1613        case MSG_ORDERED_TAG:
1614                atomic_inc(&dev->dev_ordered_sync);
1615                smp_mb__after_atomic_inc();
1616
1617                pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1618                         " se_ordered_id: %u\n",
1619                         cmd->t_task_cdb[0], cmd->se_ordered_id);
1620
1621                /*
1622                 * Execute an ORDERED command if no other older commands
1623                 * exist that need to be completed first.
1624                 */
1625                if (!atomic_read(&dev->simple_cmds))
1626                        return false;
1627                break;
1628        default:
1629                /*
1630                 * For SIMPLE and UNTAGGED Task Attribute commands
1631                 */
1632                atomic_inc(&dev->simple_cmds);
1633                smp_mb__after_atomic_inc();
1634                break;
1635        }
1636
1637        if (atomic_read(&dev->dev_ordered_sync) == 0)
1638                return false;
1639
1640        spin_lock(&dev->delayed_cmd_lock);
1641        list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1642        spin_unlock(&dev->delayed_cmd_lock);
1643
1644        pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1645                " delayed CMD list, se_ordered_id: %u\n",
1646                cmd->t_task_cdb[0], cmd->sam_task_attr,
1647                cmd->se_ordered_id);
1648        return true;
1649}
1650
1651void target_execute_cmd(struct se_cmd *cmd)
1652{
1653        /*
1654         * If the received CDB has aleady been aborted stop processing it here.
1655         */
1656        if (transport_check_aborted_status(cmd, 1)) {
1657                complete(&cmd->transport_lun_stop_comp);
1658                return;
1659        }
1660
1661        /*
1662         * Determine if IOCTL context caller in requesting the stopping of this
1663         * command for LUN shutdown purposes.
1664         */
1665        spin_lock_irq(&cmd->t_state_lock);
1666        if (cmd->transport_state & CMD_T_LUN_STOP) {
1667                pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
1668                        __func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
1669
1670                cmd->transport_state &= ~CMD_T_ACTIVE;
1671                spin_unlock_irq(&cmd->t_state_lock);
1672                complete(&cmd->transport_lun_stop_comp);
1673                return;
1674        }
1675        /*
1676         * Determine if frontend context caller is requesting the stopping of
1677         * this command for frontend exceptions.
1678         */
1679        if (cmd->transport_state & CMD_T_STOP) {
1680                pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1681                        __func__, __LINE__,
1682                        cmd->se_tfo->get_task_tag(cmd));
1683
1684                spin_unlock_irq(&cmd->t_state_lock);
1685                complete(&cmd->t_transport_stop_comp);
1686                return;
1687        }
1688
1689        cmd->t_state = TRANSPORT_PROCESSING;
1690        cmd->transport_state |= CMD_T_ACTIVE;
1691        spin_unlock_irq(&cmd->t_state_lock);
1692
1693        if (!target_handle_task_attr(cmd))
1694                __target_execute_cmd(cmd);
1695}
1696EXPORT_SYMBOL(target_execute_cmd);
1697
1698/*
1699 * Process all commands up to the last received ORDERED task attribute which
1700 * requires another blocking boundary
1701 */
1702static void target_restart_delayed_cmds(struct se_device *dev)
1703{
1704        for (;;) {
1705                struct se_cmd *cmd;
1706
1707                spin_lock(&dev->delayed_cmd_lock);
1708                if (list_empty(&dev->delayed_cmd_list)) {
1709                        spin_unlock(&dev->delayed_cmd_lock);
1710                        break;
1711                }
1712
1713                cmd = list_entry(dev->delayed_cmd_list.next,
1714                                 struct se_cmd, se_delayed_node);
1715                list_del(&cmd->se_delayed_node);
1716                spin_unlock(&dev->delayed_cmd_lock);
1717
1718                __target_execute_cmd(cmd);
1719
1720                if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1721                        break;
1722        }
1723}
1724
1725/*
1726 * Called from I/O completion to determine which dormant/delayed
1727 * and ordered cmds need to have their tasks added to the execution queue.
1728 */
1729static void transport_complete_task_attr(struct se_cmd *cmd)
1730{
1731        struct se_device *dev = cmd->se_dev;
1732
1733        if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1734                return;
1735
1736        if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1737                atomic_dec(&dev->simple_cmds);
1738                smp_mb__after_atomic_dec();
1739                dev->dev_cur_ordered_id++;
1740                pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1741                        " SIMPLE: %u\n", dev->dev_cur_ordered_id,
1742                        cmd->se_ordered_id);
1743        } else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1744                dev->dev_cur_ordered_id++;
1745                pr_debug("Incremented dev_cur_ordered_id: %u for"
1746                        " HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1747                        cmd->se_ordered_id);
1748        } else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1749                atomic_dec(&dev->dev_ordered_sync);
1750                smp_mb__after_atomic_dec();
1751
1752                dev->dev_cur_ordered_id++;
1753                pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1754                        " %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1755        }
1756
1757        target_restart_delayed_cmds(dev);
1758}
1759
1760static void transport_complete_qf(struct se_cmd *cmd)
1761{
1762        int ret = 0;
1763
1764        transport_complete_task_attr(cmd);
1765
1766        if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1767                ret = cmd->se_tfo->queue_status(cmd);
1768                if (ret)
1769                        goto out;
1770        }
1771
1772        switch (cmd->data_direction) {
1773        case DMA_FROM_DEVICE:
1774                ret = cmd->se_tfo->queue_data_in(cmd);
1775                break;
1776        case DMA_TO_DEVICE:
1777                if (cmd->t_bidi_data_sg) {
1778                        ret = cmd->se_tfo->queue_data_in(cmd);
1779                        if (ret < 0)
1780                                break;
1781                }
1782                /* Fall through for DMA_TO_DEVICE */
1783        case DMA_NONE:
1784                ret = cmd->se_tfo->queue_status(cmd);
1785                break;
1786        default:
1787                break;
1788        }
1789
1790out:
1791        if (ret < 0) {
1792                transport_handle_queue_full(cmd, cmd->se_dev);
1793                return;
1794        }
1795        transport_lun_remove_cmd(cmd);
1796        transport_cmd_check_stop_to_fabric(cmd);
1797}
1798
1799static void transport_handle_queue_full(
1800        struct se_cmd *cmd,
1801        struct se_device *dev)
1802{
1803        spin_lock_irq(&dev->qf_cmd_lock);
1804        list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1805        atomic_inc(&dev->dev_qf_count);
1806        smp_mb__after_atomic_inc();
1807        spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1808
1809        schedule_work(&cmd->se_dev->qf_work_queue);
1810}
1811
1812static void target_complete_ok_work(struct work_struct *work)
1813{
1814        struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1815        int ret;
1816
1817        /*
1818         * Check if we need to move delayed/dormant tasks from cmds on the
1819         * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1820         * Attribute.
1821         */
1822        transport_complete_task_attr(cmd);
1823
1824        /*
1825         * Check to schedule QUEUE_FULL work, or execute an existing
1826         * cmd->transport_qf_callback()
1827         */
1828        if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1829                schedule_work(&cmd->se_dev->qf_work_queue);
1830
1831        /*
1832         * Check if we need to send a sense buffer from
1833         * the struct se_cmd in question.
1834         */
1835        if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1836                WARN_ON(!cmd->scsi_status);
1837                ret = transport_send_check_condition_and_sense(
1838                                        cmd, 0, 1);
1839                if (ret == -EAGAIN || ret == -ENOMEM)
1840                        goto queue_full;
1841
1842                transport_lun_remove_cmd(cmd);
1843                transport_cmd_check_stop_to_fabric(cmd);
1844                return;
1845        }
1846        /*
1847         * Check for a callback, used by amongst other things
1848         * XDWRITE_READ_10 emulation.
1849         */
1850        if (cmd->transport_complete_callback)
1851                cmd->transport_complete_callback(cmd);
1852
1853        switch (cmd->data_direction) {
1854        case DMA_FROM_DEVICE:
1855                spin_lock(&cmd->se_lun->lun_sep_lock);
1856                if (cmd->se_lun->lun_sep) {
1857                        cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1858                                        cmd->data_length;
1859                }
1860                spin_unlock(&cmd->se_lun->lun_sep_lock);
1861
1862                ret = cmd->se_tfo->queue_data_in(cmd);
1863                if (ret == -EAGAIN || ret == -ENOMEM)
1864                        goto queue_full;
1865                break;
1866        case DMA_TO_DEVICE:
1867                spin_lock(&cmd->se_lun->lun_sep_lock);
1868                if (cmd->se_lun->lun_sep) {
1869                        cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
1870                                cmd->data_length;
1871                }
1872                spin_unlock(&cmd->se_lun->lun_sep_lock);
1873                /*
1874                 * Check if we need to send READ payload for BIDI-COMMAND
1875                 */
1876                if (cmd->t_bidi_data_sg) {
1877                        spin_lock(&cmd->se_lun->lun_sep_lock);
1878                        if (cmd->se_lun->lun_sep) {
1879                                cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1880                                        cmd->data_length;
1881                        }
1882                        spin_unlock(&cmd->se_lun->lun_sep_lock);
1883                        ret = cmd->se_tfo->queue_data_in(cmd);
1884                        if (ret == -EAGAIN || ret == -ENOMEM)
1885                                goto queue_full;
1886                        break;
1887                }
1888                /* Fall through for DMA_TO_DEVICE */
1889        case DMA_NONE:
1890                ret = cmd->se_tfo->queue_status(cmd);
1891                if (ret == -EAGAIN || ret == -ENOMEM)
1892                        goto queue_full;
1893                break;
1894        default:
1895                break;
1896        }
1897
1898        transport_lun_remove_cmd(cmd);
1899        transport_cmd_check_stop_to_fabric(cmd);
1900        return;
1901
1902queue_full:
1903        pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
1904                " data_direction: %d\n", cmd, cmd->data_direction);
1905        cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1906        transport_handle_queue_full(cmd, cmd->se_dev);
1907}
1908
1909static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
1910{
1911        struct scatterlist *sg;
1912        int count;
1913
1914        for_each_sg(sgl, sg, nents, count)
1915                __free_page(sg_page(sg));
1916
1917        kfree(sgl);
1918}
1919
1920static inline void transport_free_pages(struct se_cmd *cmd)
1921{
1922        if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
1923                return;
1924
1925        transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
1926        cmd->t_data_sg = NULL;
1927        cmd->t_data_nents = 0;
1928
1929        transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
1930        cmd->t_bidi_data_sg = NULL;
1931        cmd->t_bidi_data_nents = 0;
1932}
1933
1934/**
1935 * transport_release_cmd - free a command
1936 * @cmd:       command to free
1937 *
1938 * This routine unconditionally frees a command, and reference counting
1939 * or list removal must be done in the caller.
1940 */
1941static void transport_release_cmd(struct se_cmd *cmd)
1942{
1943        BUG_ON(!cmd->se_tfo);
1944
1945        if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1946                core_tmr_release_req(cmd->se_tmr_req);
1947        if (cmd->t_task_cdb != cmd->__t_task_cdb)
1948                kfree(cmd->t_task_cdb);
1949        /*
1950         * If this cmd has been setup with target_get_sess_cmd(), drop
1951         * the kref and call ->release_cmd() in kref callback.
1952         */
1953         if (cmd->check_release != 0) {
1954                target_put_sess_cmd(cmd->se_sess, cmd);
1955                return;
1956        }
1957        cmd->se_tfo->release_cmd(cmd);
1958}
1959
1960/**
1961 * transport_put_cmd - release a reference to a command
1962 * @cmd:       command to release
1963 *
1964 * This routine releases our reference to the command and frees it if possible.
1965 */
1966static void transport_put_cmd(struct se_cmd *cmd)
1967{
1968        unsigned long flags;
1969
1970        spin_lock_irqsave(&cmd->t_state_lock, flags);
1971        if (atomic_read(&cmd->t_fe_count) &&
1972            !atomic_dec_and_test(&cmd->t_fe_count)) {
1973                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1974                return;
1975        }
1976
1977        if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
1978                cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
1979                target_remove_from_state_list(cmd);
1980        }
1981        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1982
1983        transport_free_pages(cmd);
1984        transport_release_cmd(cmd);
1985        return;
1986}
1987
1988void *transport_kmap_data_sg(struct se_cmd *cmd)
1989{
1990        struct scatterlist *sg = cmd->t_data_sg;
1991        struct page **pages;
1992        int i;
1993
1994        /*
1995         * We need to take into account a possible offset here for fabrics like
1996         * tcm_loop who may be using a contig buffer from the SCSI midlayer for
1997         * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
1998         */
1999        if (!cmd->t_data_nents)
2000                return NULL;
2001
2002        BUG_ON(!sg);
2003        if (cmd->t_data_nents == 1)
2004                return kmap(sg_page(sg)) + sg->offset;
2005
2006        /* >1 page. use vmap */
2007        pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2008        if (!pages)
2009                return NULL;
2010
2011        /* convert sg[] to pages[] */
2012        for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2013                pages[i] = sg_page(sg);
2014        }
2015
2016        cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2017        kfree(pages);
2018        if (!cmd->t_data_vmap)
2019                return NULL;
2020
2021        return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2022}
2023EXPORT_SYMBOL(transport_kmap_data_sg);
2024
2025void transport_kunmap_data_sg(struct se_cmd *cmd)
2026{
2027        if (!cmd->t_data_nents) {
2028                return;
2029        } else if (cmd->t_data_nents == 1) {
2030                kunmap(sg_page(cmd->t_data_sg));
2031                return;
2032        }
2033
2034        vunmap(cmd->t_data_vmap);
2035        cmd->t_data_vmap = NULL;
2036}
2037EXPORT_SYMBOL(transport_kunmap_data_sg);
2038
2039static int
2040transport_generic_get_mem(struct se_cmd *cmd)
2041{
2042        u32 length = cmd->data_length;
2043        unsigned int nents;
2044        struct page *page;
2045        gfp_t zero_flag;
2046        int i = 0;
2047
2048        nents = DIV_ROUND_UP(length, PAGE_SIZE);
2049        cmd->t_data_sg = kmalloc(sizeof(struct scatterlist) * nents, GFP_KERNEL);
2050        if (!cmd->t_data_sg)
2051                return -ENOMEM;
2052
2053        cmd->t_data_nents = nents;
2054        sg_init_table(cmd->t_data_sg, nents);
2055
2056        zero_flag = cmd->se_cmd_flags & SCF_SCSI_DATA_CDB ? 0 : __GFP_ZERO;
2057
2058        while (length) {
2059                u32 page_len = min_t(u32, length, PAGE_SIZE);
2060                page = alloc_page(GFP_KERNEL | zero_flag);
2061                if (!page)
2062                        goto out;
2063
2064                sg_set_page(&cmd->t_data_sg[i], page, page_len, 0);
2065                length -= page_len;
2066                i++;
2067        }
2068        return 0;
2069
2070out:
2071        while (i > 0) {
2072                i--;
2073                __free_page(sg_page(&cmd->t_data_sg[i]));
2074        }
2075        kfree(cmd->t_data_sg);
2076        cmd->t_data_sg = NULL;
2077        return -ENOMEM;
2078}
2079
2080/*
2081 * Allocate any required resources to execute the command.  For writes we
2082 * might not have the payload yet, so notify the fabric via a call to
2083 * ->write_pending instead. Otherwise place it on the execution queue.
2084 */
2085sense_reason_t
2086transport_generic_new_cmd(struct se_cmd *cmd)
2087{
2088        int ret = 0;
2089
2090        /*
2091         * Determine is the TCM fabric module has already allocated physical
2092         * memory, and is directly calling transport_generic_map_mem_to_cmd()
2093         * beforehand.
2094         */
2095        if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2096            cmd->data_length) {
2097                ret = transport_generic_get_mem(cmd);
2098                if (ret < 0)
2099                        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2100        }
2101
2102        atomic_inc(&cmd->t_fe_count);
2103
2104        /*
2105         * If this command is not a write we can execute it right here,
2106         * for write buffers we need to notify the fabric driver first
2107         * and let it call back once the write buffers are ready.
2108         */
2109        target_add_to_state_list(cmd);
2110        if (cmd->data_direction != DMA_TO_DEVICE) {
2111                target_execute_cmd(cmd);
2112                return 0;
2113        }
2114
2115        spin_lock_irq(&cmd->t_state_lock);
2116        cmd->t_state = TRANSPORT_WRITE_PENDING;
2117        spin_unlock_irq(&cmd->t_state_lock);
2118
2119        transport_cmd_check_stop(cmd, false);
2120
2121        ret = cmd->se_tfo->write_pending(cmd);
2122        if (ret == -EAGAIN || ret == -ENOMEM)
2123                goto queue_full;
2124
2125        /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2126        WARN_ON(ret);
2127
2128        return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2129
2130queue_full:
2131        pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2132        cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2133        transport_handle_queue_full(cmd, cmd->se_dev);
2134        return 0;
2135}
2136EXPORT_SYMBOL(transport_generic_new_cmd);
2137
2138static void transport_write_pending_qf(struct se_cmd *cmd)
2139{
2140        int ret;
2141
2142        ret = cmd->se_tfo->write_pending(cmd);
2143        if (ret == -EAGAIN || ret == -ENOMEM) {
2144                pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2145                         cmd);
2146                transport_handle_queue_full(cmd, cmd->se_dev);
2147        }
2148}
2149
2150void transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2151{
2152        if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2153                if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2154                         transport_wait_for_tasks(cmd);
2155
2156                transport_release_cmd(cmd);
2157        } else {
2158                if (wait_for_tasks)
2159                        transport_wait_for_tasks(cmd);
2160
2161                core_dec_lacl_count(cmd->se_sess->se_node_acl, cmd);
2162
2163                if (cmd->se_lun)
2164                        transport_lun_remove_cmd(cmd);
2165
2166                transport_put_cmd(cmd);
2167        }
2168}
2169EXPORT_SYMBOL(transport_generic_free_cmd);
2170
2171/* target_get_sess_cmd - Add command to active ->sess_cmd_list
2172 * @se_sess:    session to reference
2173 * @se_cmd:     command descriptor to add
2174 * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2175 */
2176static int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2177                               bool ack_kref)
2178{
2179        unsigned long flags;
2180        int ret = 0;
2181
2182        kref_init(&se_cmd->cmd_kref);
2183        /*
2184         * Add a second kref if the fabric caller is expecting to handle
2185         * fabric acknowledgement that requires two target_put_sess_cmd()
2186         * invocations before se_cmd descriptor release.
2187         */
2188        if (ack_kref == true) {
2189                kref_get(&se_cmd->cmd_kref);
2190                se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2191        }
2192
2193        spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2194        if (se_sess->sess_tearing_down) {
2195                ret = -ESHUTDOWN;
2196                goto out;
2197        }
2198        list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2199        se_cmd->check_release = 1;
2200
2201out:
2202        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2203        return ret;
2204}
2205
2206static void target_release_cmd_kref(struct kref *kref)
2207{
2208        struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2209        struct se_session *se_sess = se_cmd->se_sess;
2210        unsigned long flags;
2211
2212        spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2213        if (list_empty(&se_cmd->se_cmd_list)) {
2214                spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2215                se_cmd->se_tfo->release_cmd(se_cmd);
2216                return;
2217        }
2218        if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2219                spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2220                complete(&se_cmd->cmd_wait_comp);
2221                return;
2222        }
2223        list_del(&se_cmd->se_cmd_list);
2224        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2225
2226        se_cmd->se_tfo->release_cmd(se_cmd);
2227}
2228
2229/* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2230 * @se_sess:    session to reference
2231 * @se_cmd:     command descriptor to drop
2232 */
2233int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2234{
2235        return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2236}
2237EXPORT_SYMBOL(target_put_sess_cmd);
2238
2239/* target_sess_cmd_list_set_waiting - Flag all commands in
2240 *         sess_cmd_list to complete cmd_wait_comp.  Set
2241 *         sess_tearing_down so no more commands are queued.
2242 * @se_sess:    session to flag
2243 */
2244void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2245{
2246        struct se_cmd *se_cmd;
2247        unsigned long flags;
2248
2249        spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2250
2251        WARN_ON(se_sess->sess_tearing_down);
2252        se_sess->sess_tearing_down = 1;
2253
2254        list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list)
2255                se_cmd->cmd_wait_set = 1;
2256
2257        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2258}
2259EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2260
2261/* target_wait_for_sess_cmds - Wait for outstanding descriptors
2262 * @se_sess:    session to wait for active I/O
2263 * @wait_for_tasks:     Make extra transport_wait_for_tasks call
2264 */
2265void target_wait_for_sess_cmds(
2266        struct se_session *se_sess,
2267        int wait_for_tasks)
2268{
2269        struct se_cmd *se_cmd, *tmp_cmd;
2270        bool rc = false;
2271
2272        list_for_each_entry_safe(se_cmd, tmp_cmd,
2273                                &se_sess->sess_cmd_list, se_cmd_list) {
2274                list_del(&se_cmd->se_cmd_list);
2275
2276                pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2277                        " %d\n", se_cmd, se_cmd->t_state,
2278                        se_cmd->se_tfo->get_cmd_state(se_cmd));
2279
2280                if (wait_for_tasks) {
2281                        pr_debug("Calling transport_wait_for_tasks se_cmd: %p t_state: %d,"
2282                                " fabric state: %d\n", se_cmd, se_cmd->t_state,
2283                                se_cmd->se_tfo->get_cmd_state(se_cmd));
2284
2285                        rc = transport_wait_for_tasks(se_cmd);
2286
2287                        pr_debug("After transport_wait_for_tasks se_cmd: %p t_state: %d,"
2288                                " fabric state: %d\n", se_cmd, se_cmd->t_state,
2289                                se_cmd->se_tfo->get_cmd_state(se_cmd));
2290                }
2291
2292                if (!rc) {
2293                        wait_for_completion(&se_cmd->cmd_wait_comp);
2294                        pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2295                                " fabric state: %d\n", se_cmd, se_cmd->t_state,
2296                                se_cmd->se_tfo->get_cmd_state(se_cmd));
2297                }
2298
2299                se_cmd->se_tfo->release_cmd(se_cmd);
2300        }
2301}
2302EXPORT_SYMBOL(target_wait_for_sess_cmds);
2303
2304/*      transport_lun_wait_for_tasks():
2305 *
2306 *      Called from ConfigFS context to stop the passed struct se_cmd to allow
2307 *      an struct se_lun to be successfully shutdown.
2308 */
2309static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
2310{
2311        unsigned long flags;
2312        int ret = 0;
2313
2314        /*
2315         * If the frontend has already requested this struct se_cmd to
2316         * be stopped, we can safely ignore this struct se_cmd.
2317         */
2318        spin_lock_irqsave(&cmd->t_state_lock, flags);
2319        if (cmd->transport_state & CMD_T_STOP) {
2320                cmd->transport_state &= ~CMD_T_LUN_STOP;
2321
2322                pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
2323                         cmd->se_tfo->get_task_tag(cmd));
2324                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2325                transport_cmd_check_stop(cmd, false);
2326                return -EPERM;
2327        }
2328        cmd->transport_state |= CMD_T_LUN_FE_STOP;
2329        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2330
2331        // XXX: audit task_flags checks.
2332        spin_lock_irqsave(&cmd->t_state_lock, flags);
2333        if ((cmd->transport_state & CMD_T_BUSY) &&
2334            (cmd->transport_state & CMD_T_SENT)) {
2335                if (!target_stop_cmd(cmd, &flags))
2336                        ret++;
2337        }
2338        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2339
2340        pr_debug("ConfigFS: cmd: %p stop tasks ret:"
2341                        " %d\n", cmd, ret);
2342        if (!ret) {
2343                pr_debug("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
2344                                cmd->se_tfo->get_task_tag(cmd));
2345                wait_for_completion(&cmd->transport_lun_stop_comp);
2346                pr_debug("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
2347                                cmd->se_tfo->get_task_tag(cmd));
2348        }
2349
2350        return 0;
2351}
2352
2353static void __transport_clear_lun_from_sessions(struct se_lun *lun)
2354{
2355        struct se_cmd *cmd = NULL;
2356        unsigned long lun_flags, cmd_flags;
2357        /*
2358         * Do exception processing and return CHECK_CONDITION status to the
2359         * Initiator Port.
2360         */
2361        spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2362        while (!list_empty(&lun->lun_cmd_list)) {
2363                cmd = list_first_entry(&lun->lun_cmd_list,
2364                       struct se_cmd, se_lun_node);
2365                list_del_init(&cmd->se_lun_node);
2366
2367                spin_lock(&cmd->t_state_lock);
2368                pr_debug("SE_LUN[%d] - Setting cmd->transport"
2369                        "_lun_stop for  ITT: 0x%08x\n",
2370                        cmd->se_lun->unpacked_lun,
2371                        cmd->se_tfo->get_task_tag(cmd));
2372                cmd->transport_state |= CMD_T_LUN_STOP;
2373                spin_unlock(&cmd->t_state_lock);
2374
2375                spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2376
2377                if (!cmd->se_lun) {
2378                        pr_err("ITT: 0x%08x, [i,t]_state: %u/%u\n",
2379                                cmd->se_tfo->get_task_tag(cmd),
2380                                cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2381                        BUG();
2382                }
2383                /*
2384                 * If the Storage engine still owns the iscsi_cmd_t, determine
2385                 * and/or stop its context.
2386                 */
2387                pr_debug("SE_LUN[%d] - ITT: 0x%08x before transport"
2388                        "_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
2389                        cmd->se_tfo->get_task_tag(cmd));
2390
2391                if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
2392                        spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2393                        continue;
2394                }
2395
2396                pr_debug("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
2397                        "_wait_for_tasks(): SUCCESS\n",
2398                        cmd->se_lun->unpacked_lun,
2399                        cmd->se_tfo->get_task_tag(cmd));
2400
2401                spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2402                if (!(cmd->transport_state & CMD_T_DEV_ACTIVE)) {
2403                        spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2404                        goto check_cond;
2405                }
2406                cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2407                target_remove_from_state_list(cmd);
2408                spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2409
2410                /*
2411                 * The Storage engine stopped this struct se_cmd before it was
2412                 * send to the fabric frontend for delivery back to the
2413                 * Initiator Node.  Return this SCSI CDB back with an
2414                 * CHECK_CONDITION status.
2415                 */
2416check_cond:
2417                transport_send_check_condition_and_sense(cmd,
2418                                TCM_NON_EXISTENT_LUN, 0);
2419                /*
2420                 *  If the fabric frontend is waiting for this iscsi_cmd_t to
2421                 * be released, notify the waiting thread now that LU has
2422                 * finished accessing it.
2423                 */
2424                spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2425                if (cmd->transport_state & CMD_T_LUN_FE_STOP) {
2426                        pr_debug("SE_LUN[%d] - Detected FE stop for"
2427                                " struct se_cmd: %p ITT: 0x%08x\n",
2428                                lun->unpacked_lun,
2429                                cmd, cmd->se_tfo->get_task_tag(cmd));
2430
2431                        spin_unlock_irqrestore(&cmd->t_state_lock,
2432                                        cmd_flags);
2433                        transport_cmd_check_stop(cmd, false);
2434                        complete(&cmd->transport_lun_fe_stop_comp);
2435                        spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2436                        continue;
2437                }
2438                pr_debug("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
2439                        lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));
2440
2441                spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2442                spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2443        }
2444        spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2445}
2446
2447static int transport_clear_lun_thread(void *p)
2448{
2449        struct se_lun *lun = p;
2450
2451        __transport_clear_lun_from_sessions(lun);
2452        complete(&lun->lun_shutdown_comp);
2453
2454        return 0;
2455}
2456
2457int transport_clear_lun_from_sessions(struct se_lun *lun)
2458{
2459        struct task_struct *kt;
2460
2461        kt = kthread_run(transport_clear_lun_thread, lun,
2462                        "tcm_cl_%u", lun->unpacked_lun);
2463        if (IS_ERR(kt)) {
2464                pr_err("Unable to start clear_lun thread\n");
2465                return PTR_ERR(kt);
2466        }
2467        wait_for_completion(&lun->lun_shutdown_comp);
2468
2469        return 0;
2470}
2471
2472/**
2473 * transport_wait_for_tasks - wait for completion to occur
2474 * @cmd:        command to wait
2475 *
2476 * Called from frontend fabric context to wait for storage engine
2477 * to pause and/or release frontend generated struct se_cmd.
2478 */
2479bool transport_wait_for_tasks(struct se_cmd *cmd)
2480{
2481        unsigned long flags;
2482
2483        spin_lock_irqsave(&cmd->t_state_lock, flags);
2484        if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2485            !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2486                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2487                return false;
2488        }
2489
2490        if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2491            !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2492                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2493                return false;
2494        }
2495        /*
2496         * If we are already stopped due to an external event (ie: LUN shutdown)
2497         * sleep until the connection can have the passed struct se_cmd back.
2498         * The cmd->transport_lun_stopped_sem will be upped by
2499         * transport_clear_lun_from_sessions() once the ConfigFS context caller
2500         * has completed its operation on the struct se_cmd.
2501         */
2502        if (cmd->transport_state & CMD_T_LUN_STOP) {
2503                pr_debug("wait_for_tasks: Stopping"
2504                        " wait_for_completion(&cmd->t_tasktransport_lun_fe"
2505                        "_stop_comp); for ITT: 0x%08x\n",
2506                        cmd->se_tfo->get_task_tag(cmd));
2507                /*
2508                 * There is a special case for WRITES where a FE exception +
2509                 * LUN shutdown means ConfigFS context is still sleeping on
2510                 * transport_lun_stop_comp in transport_lun_wait_for_tasks().
2511                 * We go ahead and up transport_lun_stop_comp just to be sure
2512                 * here.
2513                 */
2514                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2515                complete(&cmd->transport_lun_stop_comp);
2516                wait_for_completion(&cmd->transport_lun_fe_stop_comp);
2517                spin_lock_irqsave(&cmd->t_state_lock, flags);
2518
2519                target_remove_from_state_list(cmd);
2520                /*
2521                 * At this point, the frontend who was the originator of this
2522                 * struct se_cmd, now owns the structure and can be released through
2523                 * normal means below.
2524                 */
2525                pr_debug("wait_for_tasks: Stopped"
2526                        " wait_for_completion(&cmd->t_tasktransport_lun_fe_"
2527                        "stop_comp); for ITT: 0x%08x\n",
2528                        cmd->se_tfo->get_task_tag(cmd));
2529
2530                cmd->transport_state &= ~CMD_T_LUN_STOP;
2531        }
2532
2533        if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2534                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2535                return false;
2536        }
2537
2538        cmd->transport_state |= CMD_T_STOP;
2539
2540        pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2541                " i_state: %d, t_state: %d, CMD_T_STOP\n",
2542                cmd, cmd->se_tfo->get_task_tag(cmd),
2543                cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2544
2545        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2546
2547        wait_for_completion(&cmd->t_transport_stop_comp);
2548
2549        spin_lock_irqsave(&cmd->t_state_lock, flags);
2550        cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2551
2552        pr_debug("wait_for_tasks: Stopped wait_for_completion("
2553                "&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2554                cmd->se_tfo->get_task_tag(cmd));
2555
2556        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2557
2558        return true;
2559}
2560EXPORT_SYMBOL(transport_wait_for_tasks);
2561
2562static int transport_get_sense_codes(
2563        struct se_cmd *cmd,
2564        u8 *asc,
2565        u8 *ascq)
2566{
2567        *asc = cmd->scsi_asc;
2568        *ascq = cmd->scsi_ascq;
2569
2570        return 0;
2571}
2572
2573int
2574transport_send_check_condition_and_sense(struct se_cmd *cmd,
2575                sense_reason_t reason, int from_transport)
2576{
2577        unsigned char *buffer = cmd->sense_buffer;
2578        unsigned long flags;
2579        u8 asc = 0, ascq = 0;
2580
2581        spin_lock_irqsave(&cmd->t_state_lock, flags);
2582        if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2583                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2584                return 0;
2585        }
2586        cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2587        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2588
2589        if (!reason && from_transport)
2590                goto after_reason;
2591
2592        if (!from_transport)
2593                cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2594
2595        /*
2596         * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2597         * SENSE KEY values from include/scsi/scsi.h
2598         */
2599        switch (reason) {
2600        case TCM_NO_SENSE:
2601                /* CURRENT ERROR */
2602                buffer[0] = 0x70;
2603                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2604                /* Not Ready */
2605                buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2606                /* NO ADDITIONAL SENSE INFORMATION */
2607                buffer[SPC_ASC_KEY_OFFSET] = 0;
2608                buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2609                break;
2610        case TCM_NON_EXISTENT_LUN:
2611                /* CURRENT ERROR */
2612                buffer[0] = 0x70;
2613                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2614                /* ILLEGAL REQUEST */
2615                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2616                /* LOGICAL UNIT NOT SUPPORTED */
2617                buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2618                break;
2619        case TCM_UNSUPPORTED_SCSI_OPCODE:
2620        case TCM_SECTOR_COUNT_TOO_MANY:
2621                /* CURRENT ERROR */
2622                buffer[0] = 0x70;
2623                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2624                /* ILLEGAL REQUEST */
2625                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2626                /* INVALID COMMAND OPERATION CODE */
2627                buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2628                break;
2629        case TCM_UNKNOWN_MODE_PAGE:
2630                /* CURRENT ERROR */
2631                buffer[0] = 0x70;
2632                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2633                /* ILLEGAL REQUEST */
2634                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2635                /* INVALID FIELD IN CDB */
2636                buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2637                break;
2638        case TCM_CHECK_CONDITION_ABORT_CMD:
2639                /* CURRENT ERROR */
2640                buffer[0] = 0x70;
2641                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2642                /* ABORTED COMMAND */
2643                buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2644                /* BUS DEVICE RESET FUNCTION OCCURRED */
2645                buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2646                buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2647                break;
2648        case TCM_INCORRECT_AMOUNT_OF_DATA:
2649                /* CURRENT ERROR */
2650                buffer[0] = 0x70;
2651                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2652                /* ABORTED COMMAND */
2653                buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2654                /* WRITE ERROR */
2655                buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2656                /* NOT ENOUGH UNSOLICITED DATA */
2657                buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2658                break;
2659        case TCM_INVALID_CDB_FIELD:
2660                /* CURRENT ERROR */
2661                buffer[0] = 0x70;
2662                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2663                /* ILLEGAL REQUEST */
2664                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2665                /* INVALID FIELD IN CDB */
2666                buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2667                break;
2668        case TCM_INVALID_PARAMETER_LIST:
2669                /* CURRENT ERROR */
2670                buffer[0] = 0x70;
2671                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2672                /* ILLEGAL REQUEST */
2673                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2674                /* INVALID FIELD IN PARAMETER LIST */
2675                buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2676                break;
2677        case TCM_UNEXPECTED_UNSOLICITED_DATA:
2678                /* CURRENT ERROR */
2679                buffer[0] = 0x70;
2680                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2681                /* ABORTED COMMAND */
2682                buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2683                /* WRITE ERROR */
2684                buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2685                /* UNEXPECTED_UNSOLICITED_DATA */
2686                buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2687                break;
2688        case TCM_SERVICE_CRC_ERROR:
2689                /* CURRENT ERROR */
2690                buffer[0] = 0x70;
2691                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2692                /* ABORTED COMMAND */
2693                buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2694                /* PROTOCOL SERVICE CRC ERROR */
2695                buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2696                /* N/A */
2697                buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2698                break;
2699        case TCM_SNACK_REJECTED:
2700                /* CURRENT ERROR */
2701                buffer[0] = 0x70;
2702                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2703                /* ABORTED COMMAND */
2704                buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2705                /* READ ERROR */
2706                buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2707                /* FAILED RETRANSMISSION REQUEST */
2708                buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2709                break;
2710        case TCM_WRITE_PROTECTED:
2711                /* CURRENT ERROR */
2712                buffer[0] = 0x70;
2713                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2714                /* DATA PROTECT */
2715                buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2716                /* WRITE PROTECTED */
2717                buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2718                break;
2719        case TCM_ADDRESS_OUT_OF_RANGE:
2720                /* CURRENT ERROR */
2721                buffer[0] = 0x70;
2722                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2723                /* ILLEGAL REQUEST */
2724                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2725                /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2726                buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2727                break;
2728        case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2729                /* CURRENT ERROR */
2730                buffer[0] = 0x70;
2731                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2732                /* UNIT ATTENTION */
2733                buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2734                core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2735                buffer[SPC_ASC_KEY_OFFSET] = asc;
2736                buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2737                break;
2738        case TCM_CHECK_CONDITION_NOT_READY:
2739                /* CURRENT ERROR */
2740                buffer[0] = 0x70;
2741                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2742                /* Not Ready */
2743                buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2744                transport_get_sense_codes(cmd, &asc, &ascq);
2745                buffer[SPC_ASC_KEY_OFFSET] = asc;
2746                buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2747                break;
2748        case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2749        default:
2750                /* CURRENT ERROR */
2751                buffer[0] = 0x70;
2752                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2753                /* ILLEGAL REQUEST */
2754                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2755                /* LOGICAL UNIT COMMUNICATION FAILURE */
2756                buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2757                break;
2758        }
2759        /*
2760         * This code uses linux/include/scsi/scsi.h SAM status codes!
2761         */
2762        cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2763        /*
2764         * Automatically padded, this value is encoded in the fabric's
2765         * data_length response PDU containing the SCSI defined sense data.
2766         */
2767        cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2768
2769after_reason:
2770        return cmd->se_tfo->queue_status(cmd);
2771}
2772EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2773
2774int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2775{
2776        if (!(cmd->transport_state & CMD_T_ABORTED))
2777                return 0;
2778
2779        if (!send_status || (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
2780                return 1;
2781
2782        pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2783                 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2784
2785        cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
2786        cmd->se_tfo->queue_status(cmd);
2787
2788        return 1;
2789}
2790EXPORT_SYMBOL(transport_check_aborted_status);
2791
2792void transport_send_task_abort(struct se_cmd *cmd)
2793{
2794        unsigned long flags;
2795
2796        spin_lock_irqsave(&cmd->t_state_lock, flags);
2797        if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION | SCF_SENT_DELAYED_TAS)) {
2798                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2799                return;
2800        }
2801        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2802
2803        /*
2804         * If there are still expected incoming fabric WRITEs, we wait
2805         * until until they have completed before sending a TASK_ABORTED
2806         * response.  This response with TASK_ABORTED status will be
2807         * queued back to fabric module by transport_check_aborted_status().
2808         */
2809        if (cmd->data_direction == DMA_TO_DEVICE) {
2810                if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2811                        cmd->transport_state |= CMD_T_ABORTED;
2812                        smp_mb__after_atomic_inc();
2813                }
2814        }
2815        cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2816
2817        transport_lun_remove_cmd(cmd);
2818
2819        pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2820                " ITT: 0x%08x\n", cmd->t_task_cdb[0],
2821                cmd->se_tfo->get_task_tag(cmd));
2822
2823        cmd->se_tfo->queue_status(cmd);
2824}
2825
2826static void target_tmr_work(struct work_struct *work)
2827{
2828        struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2829        struct se_device *dev = cmd->se_dev;
2830        struct se_tmr_req *tmr = cmd->se_tmr_req;
2831        int ret;
2832
2833        switch (tmr->function) {
2834        case TMR_ABORT_TASK:
2835                core_tmr_abort_task(dev, tmr, cmd->se_sess);
2836                break;
2837        case TMR_ABORT_TASK_SET:
2838        case TMR_CLEAR_ACA:
2839        case TMR_CLEAR_TASK_SET:
2840                tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2841                break;
2842        case TMR_LUN_RESET:
2843                ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2844                tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2845                                         TMR_FUNCTION_REJECTED;
2846                break;
2847        case TMR_TARGET_WARM_RESET:
2848                tmr->response = TMR_FUNCTION_REJECTED;
2849                break;
2850        case TMR_TARGET_COLD_RESET:
2851                tmr->response = TMR_FUNCTION_REJECTED;
2852                break;
2853        default:
2854                pr_err("Uknown TMR function: 0x%02x.\n",
2855                                tmr->function);
2856                tmr->response = TMR_FUNCTION_REJECTED;
2857                break;
2858        }
2859
2860        cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2861        cmd->se_tfo->queue_tm_rsp(cmd);
2862
2863        transport_cmd_check_stop_to_fabric(cmd);
2864}
2865
2866int transport_generic_handle_tmr(
2867        struct se_cmd *cmd)
2868{
2869        INIT_WORK(&cmd->work, target_tmr_work);
2870        queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2871        return 0;
2872}
2873EXPORT_SYMBOL(transport_generic_handle_tmr);
2874
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