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 transport_put_cmd(struct se_cmd *cmd);
  69static void target_complete_ok_work(struct work_struct *work);
  70
  71int init_se_kmem_caches(void)
  72{
  73        se_sess_cache = kmem_cache_create("se_sess_cache",
  74                        sizeof(struct se_session), __alignof__(struct se_session),
  75                        0, NULL);
  76        if (!se_sess_cache) {
  77                pr_err("kmem_cache_create() for struct se_session"
  78                                " failed\n");
  79                goto out;
  80        }
  81        se_ua_cache = kmem_cache_create("se_ua_cache",
  82                        sizeof(struct se_ua), __alignof__(struct se_ua),
  83                        0, NULL);
  84        if (!se_ua_cache) {
  85                pr_err("kmem_cache_create() for struct se_ua failed\n");
  86                goto out_free_sess_cache;
  87        }
  88        t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  89                        sizeof(struct t10_pr_registration),
  90                        __alignof__(struct t10_pr_registration), 0, NULL);
  91        if (!t10_pr_reg_cache) {
  92                pr_err("kmem_cache_create() for struct t10_pr_registration"
  93                                " failed\n");
  94                goto out_free_ua_cache;
  95        }
  96        t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  97                        sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  98                        0, NULL);
  99        if (!t10_alua_lu_gp_cache) {
 100                pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 101                                " failed\n");
 102                goto out_free_pr_reg_cache;
 103        }
 104        t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 105                        sizeof(struct t10_alua_lu_gp_member),
 106                        __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 107        if (!t10_alua_lu_gp_mem_cache) {
 108                pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 109                                "cache failed\n");
 110                goto out_free_lu_gp_cache;
 111        }
 112        t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 113                        sizeof(struct t10_alua_tg_pt_gp),
 114                        __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 115        if (!t10_alua_tg_pt_gp_cache) {
 116                pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 117                                "cache failed\n");
 118                goto out_free_lu_gp_mem_cache;
 119        }
 120        t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
 121                        "t10_alua_tg_pt_gp_mem_cache",
 122                        sizeof(struct t10_alua_tg_pt_gp_member),
 123                        __alignof__(struct t10_alua_tg_pt_gp_member),
 124                        0, NULL);
 125        if (!t10_alua_tg_pt_gp_mem_cache) {
 126                pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 127                                "mem_t failed\n");
 128                goto out_free_tg_pt_gp_cache;
 129        }
 130
 131        target_completion_wq = alloc_workqueue("target_completion",
 132                                               WQ_MEM_RECLAIM, 0);
 133        if (!target_completion_wq)
 134                goto out_free_tg_pt_gp_mem_cache;
 135
 136        return 0;
 137
 138out_free_tg_pt_gp_mem_cache:
 139        kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 140out_free_tg_pt_gp_cache:
 141        kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 142out_free_lu_gp_mem_cache:
 143        kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 144out_free_lu_gp_cache:
 145        kmem_cache_destroy(t10_alua_lu_gp_cache);
 146out_free_pr_reg_cache:
 147        kmem_cache_destroy(t10_pr_reg_cache);
 148out_free_ua_cache:
 149        kmem_cache_destroy(se_ua_cache);
 150out_free_sess_cache:
 151        kmem_cache_destroy(se_sess_cache);
 152out:
 153        return -ENOMEM;
 154}
 155
 156void release_se_kmem_caches(void)
 157{
 158        destroy_workqueue(target_completion_wq);
 159        kmem_cache_destroy(se_sess_cache);
 160        kmem_cache_destroy(se_ua_cache);
 161        kmem_cache_destroy(t10_pr_reg_cache);
 162        kmem_cache_destroy(t10_alua_lu_gp_cache);
 163        kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 164        kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 165        kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 166}
 167
 168/* This code ensures unique mib indexes are handed out. */
 169static DEFINE_SPINLOCK(scsi_mib_index_lock);
 170static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 171
 172/*
 173 * Allocate a new row index for the entry type specified
 174 */
 175u32 scsi_get_new_index(scsi_index_t type)
 176{
 177        u32 new_index;
 178
 179        BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 180
 181        spin_lock(&scsi_mib_index_lock);
 182        new_index = ++scsi_mib_index[type];
 183        spin_unlock(&scsi_mib_index_lock);
 184
 185        return new_index;
 186}
 187
 188void transport_subsystem_check_init(void)
 189{
 190        int ret;
 191        static int sub_api_initialized;
 192
 193        if (sub_api_initialized)
 194                return;
 195
 196        ret = request_module("target_core_iblock");
 197        if (ret != 0)
 198                pr_err("Unable to load target_core_iblock\n");
 199
 200        ret = request_module("target_core_file");
 201        if (ret != 0)
 202                pr_err("Unable to load target_core_file\n");
 203
 204        ret = request_module("target_core_pscsi");
 205        if (ret != 0)
 206                pr_err("Unable to load target_core_pscsi\n");
 207
 208        sub_api_initialized = 1;
 209}
 210
 211struct se_session *transport_init_session(void)
 212{
 213        struct se_session *se_sess;
 214
 215        se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 216        if (!se_sess) {
 217                pr_err("Unable to allocate struct se_session from"
 218                                " se_sess_cache\n");
 219                return ERR_PTR(-ENOMEM);
 220        }
 221        INIT_LIST_HEAD(&se_sess->sess_list);
 222        INIT_LIST_HEAD(&se_sess->sess_acl_list);
 223        INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 224        INIT_LIST_HEAD(&se_sess->sess_wait_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                snprintf(buf, sizeof(buf),
 911                        "T10 VPD Binary Device Identifier: %s\n",
 912                        &vpd->device_identifier[0]);
 913                break;
 914        case 0x02: /* ASCII */
 915                snprintf(buf, sizeof(buf),
 916                        "T10 VPD ASCII Device Identifier: %s\n",
 917                        &vpd->device_identifier[0]);
 918                break;
 919        case 0x03: /* UTF-8 */
 920                snprintf(buf, sizeof(buf),
 921                        "T10 VPD UTF-8 Device Identifier: %s\n",
 922                        &vpd->device_identifier[0]);
 923                break;
 924        default:
 925                sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
 926                        " 0x%02x", vpd->device_identifier_code_set);
 927                ret = -EINVAL;
 928                break;
 929        }
 930
 931        if (p_buf)
 932                strncpy(p_buf, buf, p_buf_len);
 933        else
 934                pr_debug("%s", buf);
 935
 936        return ret;
 937}
 938
 939int
 940transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
 941{
 942        static const char hex_str[] = "0123456789abcdef";
 943        int j = 0, i = 4; /* offset to start of the identifier */
 944
 945        /*
 946         * The VPD Code Set (encoding)
 947         *
 948         * from spc3r23.pdf Section 7.6.3.1 Table 296
 949         */
 950        vpd->device_identifier_code_set = (page_83[0] & 0x0f);
 951        switch (vpd->device_identifier_code_set) {
 952        case 0x01: /* Binary */
 953                vpd->device_identifier[j++] =
 954                                hex_str[vpd->device_identifier_type];
 955                while (i < (4 + page_83[3])) {
 956                        vpd->device_identifier[j++] =
 957                                hex_str[(page_83[i] & 0xf0) >> 4];
 958                        vpd->device_identifier[j++] =
 959                                hex_str[page_83[i] & 0x0f];
 960                        i++;
 961                }
 962                break;
 963        case 0x02: /* ASCII */
 964        case 0x03: /* UTF-8 */
 965                while (i < (4 + page_83[3]))
 966                        vpd->device_identifier[j++] = page_83[i++];
 967                break;
 968        default:
 969                break;
 970        }
 971
 972        return transport_dump_vpd_ident(vpd, NULL, 0);
 973}
 974EXPORT_SYMBOL(transport_set_vpd_ident);
 975
 976sense_reason_t
 977target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
 978{
 979        struct se_device *dev = cmd->se_dev;
 980
 981        if (cmd->unknown_data_length) {
 982                cmd->data_length = size;
 983        } else if (size != cmd->data_length) {
 984                pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
 985                        " %u does not match SCSI CDB Length: %u for SAM Opcode:"
 986                        " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
 987                                cmd->data_length, size, cmd->t_task_cdb[0]);
 988
 989                if (cmd->data_direction == DMA_TO_DEVICE) {
 990                        pr_err("Rejecting underflow/overflow"
 991                                        " WRITE data\n");
 992                        return TCM_INVALID_CDB_FIELD;
 993                }
 994                /*
 995                 * Reject READ_* or WRITE_* with overflow/underflow for
 996                 * type SCF_SCSI_DATA_CDB.
 997                 */
 998                if (dev->dev_attrib.block_size != 512)  {
 999                        pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1000                                " CDB on non 512-byte sector setup subsystem"
1001                                " plugin: %s\n", dev->transport->name);
1002                        /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1003                        return TCM_INVALID_CDB_FIELD;
1004                }
1005                /*
1006                 * For the overflow case keep the existing fabric provided
1007                 * ->data_length.  Otherwise for the underflow case, reset
1008                 * ->data_length to the smaller SCSI expected data transfer
1009                 * length.
1010                 */
1011                if (size > cmd->data_length) {
1012                        cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1013                        cmd->residual_count = (size - cmd->data_length);
1014                } else {
1015                        cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1016                        cmd->residual_count = (cmd->data_length - size);
1017                        cmd->data_length = size;
1018                }
1019        }
1020
1021        return 0;
1022
1023}
1024
1025/*
1026 * Used by fabric modules containing a local struct se_cmd within their
1027 * fabric dependent per I/O descriptor.
1028 */
1029void transport_init_se_cmd(
1030        struct se_cmd *cmd,
1031        struct target_core_fabric_ops *tfo,
1032        struct se_session *se_sess,
1033        u32 data_length,
1034        int data_direction,
1035        int task_attr,
1036        unsigned char *sense_buffer)
1037{
1038        INIT_LIST_HEAD(&cmd->se_lun_node);
1039        INIT_LIST_HEAD(&cmd->se_delayed_node);
1040        INIT_LIST_HEAD(&cmd->se_qf_node);
1041        INIT_LIST_HEAD(&cmd->se_cmd_list);
1042        INIT_LIST_HEAD(&cmd->state_list);
1043        init_completion(&cmd->transport_lun_fe_stop_comp);
1044        init_completion(&cmd->transport_lun_stop_comp);
1045        init_completion(&cmd->t_transport_stop_comp);
1046        init_completion(&cmd->cmd_wait_comp);
1047        init_completion(&cmd->task_stop_comp);
1048        spin_lock_init(&cmd->t_state_lock);
1049        cmd->transport_state = CMD_T_DEV_ACTIVE;
1050
1051        cmd->se_tfo = tfo;
1052        cmd->se_sess = se_sess;
1053        cmd->data_length = data_length;
1054        cmd->data_direction = data_direction;
1055        cmd->sam_task_attr = task_attr;
1056        cmd->sense_buffer = sense_buffer;
1057
1058        cmd->state_active = false;
1059}
1060EXPORT_SYMBOL(transport_init_se_cmd);
1061
1062static sense_reason_t
1063transport_check_alloc_task_attr(struct se_cmd *cmd)
1064{
1065        struct se_device *dev = cmd->se_dev;
1066
1067        /*
1068         * Check if SAM Task Attribute emulation is enabled for this
1069         * struct se_device storage object
1070         */
1071        if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1072                return 0;
1073
1074        if (cmd->sam_task_attr == MSG_ACA_TAG) {
1075                pr_debug("SAM Task Attribute ACA"
1076                        " emulation is not supported\n");
1077                return TCM_INVALID_CDB_FIELD;
1078        }
1079        /*
1080         * Used to determine when ORDERED commands should go from
1081         * Dormant to Active status.
1082         */
1083        cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1084        smp_mb__after_atomic_inc();
1085        pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1086                        cmd->se_ordered_id, cmd->sam_task_attr,
1087                        dev->transport->name);
1088        return 0;
1089}
1090
1091sense_reason_t
1092target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1093{
1094        struct se_device *dev = cmd->se_dev;
1095        unsigned long flags;
1096        sense_reason_t ret;
1097
1098        /*
1099         * Ensure that the received CDB is less than the max (252 + 8) bytes
1100         * for VARIABLE_LENGTH_CMD
1101         */
1102        if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1103                pr_err("Received SCSI CDB with command_size: %d that"
1104                        " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1105                        scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1106                return TCM_INVALID_CDB_FIELD;
1107        }
1108        /*
1109         * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1110         * allocate the additional extended CDB buffer now..  Otherwise
1111         * setup the pointer from __t_task_cdb to t_task_cdb.
1112         */
1113        if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1114                cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1115                                                GFP_KERNEL);
1116                if (!cmd->t_task_cdb) {
1117                        pr_err("Unable to allocate cmd->t_task_cdb"
1118                                " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1119                                scsi_command_size(cdb),
1120                                (unsigned long)sizeof(cmd->__t_task_cdb));
1121                        return TCM_OUT_OF_RESOURCES;
1122                }
1123        } else
1124                cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1125        /*
1126         * Copy the original CDB into cmd->
1127         */
1128        memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1129
1130        /*
1131         * Check for an existing UNIT ATTENTION condition
1132         */
1133        ret = target_scsi3_ua_check(cmd);
1134        if (ret)
1135                return ret;
1136
1137        ret = target_alua_state_check(cmd);
1138        if (ret)
1139                return ret;
1140
1141        ret = target_check_reservation(cmd);
1142        if (ret) {
1143                cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1144                return ret;
1145        }
1146
1147        ret = dev->transport->parse_cdb(cmd);
1148        if (ret)
1149                return ret;
1150
1151        ret = transport_check_alloc_task_attr(cmd);
1152        if (ret)
1153                return ret;
1154
1155        spin_lock_irqsave(&cmd->t_state_lock, flags);
1156        cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1157        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1158
1159        spin_lock(&cmd->se_lun->lun_sep_lock);
1160        if (cmd->se_lun->lun_sep)
1161                cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1162        spin_unlock(&cmd->se_lun->lun_sep_lock);
1163        return 0;
1164}
1165EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1166
1167/*
1168 * Used by fabric module frontends to queue tasks directly.
1169 * Many only be used from process context only
1170 */
1171int transport_handle_cdb_direct(
1172        struct se_cmd *cmd)
1173{
1174        sense_reason_t ret;
1175
1176        if (!cmd->se_lun) {
1177                dump_stack();
1178                pr_err("cmd->se_lun is NULL\n");
1179                return -EINVAL;
1180        }
1181        if (in_interrupt()) {
1182                dump_stack();
1183                pr_err("transport_generic_handle_cdb cannot be called"
1184                                " from interrupt context\n");
1185                return -EINVAL;
1186        }
1187        /*
1188         * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1189         * outstanding descriptors are handled correctly during shutdown via
1190         * transport_wait_for_tasks()
1191         *
1192         * Also, we don't take cmd->t_state_lock here as we only expect
1193         * this to be called for initial descriptor submission.
1194         */
1195        cmd->t_state = TRANSPORT_NEW_CMD;
1196        cmd->transport_state |= CMD_T_ACTIVE;
1197
1198        /*
1199         * transport_generic_new_cmd() is already handling QUEUE_FULL,
1200         * so follow TRANSPORT_NEW_CMD processing thread context usage
1201         * and call transport_generic_request_failure() if necessary..
1202         */
1203        ret = transport_generic_new_cmd(cmd);
1204        if (ret)
1205                transport_generic_request_failure(cmd, ret);
1206        return 0;
1207}
1208EXPORT_SYMBOL(transport_handle_cdb_direct);
1209
1210static sense_reason_t
1211transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1212                u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1213{
1214        if (!sgl || !sgl_count)
1215                return 0;
1216
1217        /*
1218         * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1219         * scatterlists already have been set to follow what the fabric
1220         * passes for the original expected data transfer length.
1221         */
1222        if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1223                pr_warn("Rejecting SCSI DATA overflow for fabric using"
1224                        " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1225                return TCM_INVALID_CDB_FIELD;
1226        }
1227
1228        cmd->t_data_sg = sgl;
1229        cmd->t_data_nents = sgl_count;
1230
1231        if (sgl_bidi && sgl_bidi_count) {
1232                cmd->t_bidi_data_sg = sgl_bidi;
1233                cmd->t_bidi_data_nents = sgl_bidi_count;
1234        }
1235        cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1236        return 0;
1237}
1238
1239/*
1240 * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1241 *                       se_cmd + use pre-allocated SGL memory.
1242 *
1243 * @se_cmd: command descriptor to submit
1244 * @se_sess: associated se_sess for endpoint
1245 * @cdb: pointer to SCSI CDB
1246 * @sense: pointer to SCSI sense buffer
1247 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1248 * @data_length: fabric expected data transfer length
1249 * @task_addr: SAM task attribute
1250 * @data_dir: DMA data direction
1251 * @flags: flags for command submission from target_sc_flags_tables
1252 * @sgl: struct scatterlist memory for unidirectional mapping
1253 * @sgl_count: scatterlist count for unidirectional mapping
1254 * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1255 * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1256 *
1257 * Returns non zero to signal active I/O shutdown failure.  All other
1258 * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1259 * but still return zero here.
1260 *
1261 * This may only be called from process context, and also currently
1262 * assumes internal allocation of fabric payload buffer by target-core.
1263 */
1264int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1265                unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1266                u32 data_length, int task_attr, int data_dir, int flags,
1267                struct scatterlist *sgl, u32 sgl_count,
1268                struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1269{
1270        struct se_portal_group *se_tpg;
1271        sense_reason_t rc;
1272        int ret;
1273
1274        se_tpg = se_sess->se_tpg;
1275        BUG_ON(!se_tpg);
1276        BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1277        BUG_ON(in_interrupt());
1278        /*
1279         * Initialize se_cmd for target operation.  From this point
1280         * exceptions are handled by sending exception status via
1281         * target_core_fabric_ops->queue_status() callback
1282         */
1283        transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1284                                data_length, data_dir, task_attr, sense);
1285        if (flags & TARGET_SCF_UNKNOWN_SIZE)
1286                se_cmd->unknown_data_length = 1;
1287        /*
1288         * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1289         * se_sess->sess_cmd_list.  A second kref_get here is necessary
1290         * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1291         * kref_put() to happen during fabric packet acknowledgement.
1292         */
1293        ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1294        if (ret)
1295                return ret;
1296        /*
1297         * Signal bidirectional data payloads to target-core
1298         */
1299        if (flags & TARGET_SCF_BIDI_OP)
1300                se_cmd->se_cmd_flags |= SCF_BIDI;
1301        /*
1302         * Locate se_lun pointer and attach it to struct se_cmd
1303         */
1304        rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1305        if (rc) {
1306                transport_send_check_condition_and_sense(se_cmd, rc, 0);
1307                target_put_sess_cmd(se_sess, se_cmd);
1308                return 0;
1309        }
1310
1311        rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1312        if (rc != 0) {
1313                transport_generic_request_failure(se_cmd, rc);
1314                return 0;
1315        }
1316        /*
1317         * When a non zero sgl_count has been passed perform SGL passthrough
1318         * mapping for pre-allocated fabric memory instead of having target
1319         * core perform an internal SGL allocation..
1320         */
1321        if (sgl_count != 0) {
1322                BUG_ON(!sgl);
1323
1324                /*
1325                 * A work-around for tcm_loop as some userspace code via
1326                 * scsi-generic do not memset their associated read buffers,
1327                 * so go ahead and do that here for type non-data CDBs.  Also
1328                 * note that this is currently guaranteed to be a single SGL
1329                 * for this case by target core in target_setup_cmd_from_cdb()
1330                 * -> transport_generic_cmd_sequencer().
1331                 */
1332                if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1333                     se_cmd->data_direction == DMA_FROM_DEVICE) {
1334                        unsigned char *buf = NULL;
1335
1336                        if (sgl)
1337                                buf = kmap(sg_page(sgl)) + sgl->offset;
1338
1339                        if (buf) {
1340                                memset(buf, 0, sgl->length);
1341                                kunmap(sg_page(sgl));
1342                        }
1343                }
1344
1345                rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1346                                sgl_bidi, sgl_bidi_count);
1347                if (rc != 0) {
1348                        transport_generic_request_failure(se_cmd, rc);
1349                        return 0;
1350                }
1351        }
1352        /*
1353         * Check if we need to delay processing because of ALUA
1354         * Active/NonOptimized primary access state..
1355         */
1356        core_alua_check_nonop_delay(se_cmd);
1357
1358        transport_handle_cdb_direct(se_cmd);
1359        return 0;
1360}
1361EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1362
1363/*
1364 * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1365 *
1366 * @se_cmd: command descriptor to submit
1367 * @se_sess: associated se_sess for endpoint
1368 * @cdb: pointer to SCSI CDB
1369 * @sense: pointer to SCSI sense buffer
1370 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1371 * @data_length: fabric expected data transfer length
1372 * @task_addr: SAM task attribute
1373 * @data_dir: DMA data direction
1374 * @flags: flags for command submission from target_sc_flags_tables
1375 *
1376 * Returns non zero to signal active I/O shutdown failure.  All other
1377 * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1378 * but still return zero here.
1379 *
1380 * This may only be called from process context, and also currently
1381 * assumes internal allocation of fabric payload buffer by target-core.
1382 *
1383 * It also assumes interal target core SGL memory allocation.
1384 */
1385int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1386                unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1387                u32 data_length, int task_attr, int data_dir, int flags)
1388{
1389        return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1390                        unpacked_lun, data_length, task_attr, data_dir,
1391                        flags, NULL, 0, NULL, 0);
1392}
1393EXPORT_SYMBOL(target_submit_cmd);
1394
1395static void target_complete_tmr_failure(struct work_struct *work)
1396{
1397        struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1398
1399        se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1400        se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1401
1402        transport_cmd_check_stop_to_fabric(se_cmd);
1403}
1404
1405/**
1406 * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1407 *                     for TMR CDBs
1408 *
1409 * @se_cmd: command descriptor to submit
1410 * @se_sess: associated se_sess for endpoint
1411 * @sense: pointer to SCSI sense buffer
1412 * @unpacked_lun: unpacked LUN to reference for struct se_lun
1413 * @fabric_context: fabric context for TMR req
1414 * @tm_type: Type of TM request
1415 * @gfp: gfp type for caller
1416 * @tag: referenced task tag for TMR_ABORT_TASK
1417 * @flags: submit cmd flags
1418 *
1419 * Callable from all contexts.
1420 **/
1421
1422int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1423                unsigned char *sense, u32 unpacked_lun,
1424                void *fabric_tmr_ptr, unsigned char tm_type,
1425                gfp_t gfp, unsigned int tag, int flags)
1426{
1427        struct se_portal_group *se_tpg;
1428        int ret;
1429
1430        se_tpg = se_sess->se_tpg;
1431        BUG_ON(!se_tpg);
1432
1433        transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1434                              0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1435        /*
1436         * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1437         * allocation failure.
1438         */
1439        ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1440        if (ret < 0)
1441                return -ENOMEM;
1442
1443        if (tm_type == TMR_ABORT_TASK)
1444                se_cmd->se_tmr_req->ref_task_tag = tag;
1445
1446        /* See target_submit_cmd for commentary */
1447        ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1448        if (ret) {
1449                core_tmr_release_req(se_cmd->se_tmr_req);
1450                return ret;
1451        }
1452
1453        ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1454        if (ret) {
1455                /*
1456                 * For callback during failure handling, push this work off
1457                 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1458                 */
1459                INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1460                schedule_work(&se_cmd->work);
1461                return 0;
1462        }
1463        transport_generic_handle_tmr(se_cmd);
1464        return 0;
1465}
1466EXPORT_SYMBOL(target_submit_tmr);
1467
1468/*
1469 * If the cmd is active, request it to be stopped and sleep until it
1470 * has completed.
1471 */
1472bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1473{
1474        bool was_active = false;
1475
1476        if (cmd->transport_state & CMD_T_BUSY) {
1477                cmd->transport_state |= CMD_T_REQUEST_STOP;
1478                spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1479
1480                pr_debug("cmd %p waiting to complete\n", cmd);
1481                wait_for_completion(&cmd->task_stop_comp);
1482                pr_debug("cmd %p stopped successfully\n", cmd);
1483
1484                spin_lock_irqsave(&cmd->t_state_lock, *flags);
1485                cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1486                cmd->transport_state &= ~CMD_T_BUSY;
1487                was_active = true;
1488        }
1489
1490        return was_active;
1491}
1492
1493/*
1494 * Handle SAM-esque emulation for generic transport request failures.
1495 */
1496void transport_generic_request_failure(struct se_cmd *cmd,
1497                sense_reason_t sense_reason)
1498{
1499        int ret = 0;
1500
1501        pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1502                " CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1503                cmd->t_task_cdb[0]);
1504        pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1505                cmd->se_tfo->get_cmd_state(cmd),
1506                cmd->t_state, sense_reason);
1507        pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1508                (cmd->transport_state & CMD_T_ACTIVE) != 0,
1509                (cmd->transport_state & CMD_T_STOP) != 0,
1510                (cmd->transport_state & CMD_T_SENT) != 0);
1511
1512        /*
1513         * For SAM Task Attribute emulation for failed struct se_cmd
1514         */
1515        transport_complete_task_attr(cmd);
1516
1517        switch (sense_reason) {
1518        case TCM_NON_EXISTENT_LUN:
1519        case TCM_UNSUPPORTED_SCSI_OPCODE:
1520        case TCM_INVALID_CDB_FIELD:
1521        case TCM_INVALID_PARAMETER_LIST:
1522        case TCM_PARAMETER_LIST_LENGTH_ERROR:
1523        case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1524        case TCM_UNKNOWN_MODE_PAGE:
1525        case TCM_WRITE_PROTECTED:
1526        case TCM_ADDRESS_OUT_OF_RANGE:
1527        case TCM_CHECK_CONDITION_ABORT_CMD:
1528        case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1529        case TCM_CHECK_CONDITION_NOT_READY:
1530                break;
1531        case TCM_OUT_OF_RESOURCES:
1532                sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1533                break;
1534        case TCM_RESERVATION_CONFLICT:
1535                /*
1536                 * No SENSE Data payload for this case, set SCSI Status
1537                 * and queue the response to $FABRIC_MOD.
1538                 *
1539                 * Uses linux/include/scsi/scsi.h SAM status codes defs
1540                 */
1541                cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1542                /*
1543                 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1544                 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1545                 * CONFLICT STATUS.
1546                 *
1547                 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1548                 */
1549                if (cmd->se_sess &&
1550                    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1551                        core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1552                                cmd->orig_fe_lun, 0x2C,
1553                                ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1554
1555                ret = cmd->se_tfo->queue_status(cmd);
1556                if (ret == -EAGAIN || ret == -ENOMEM)
1557                        goto queue_full;
1558                goto check_stop;
1559        default:
1560                pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1561                        cmd->t_task_cdb[0], sense_reason);
1562                sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1563                break;
1564        }
1565
1566        ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1567        if (ret == -EAGAIN || ret == -ENOMEM)
1568                goto queue_full;
1569
1570check_stop:
1571        transport_lun_remove_cmd(cmd);
1572        if (!transport_cmd_check_stop_to_fabric(cmd))
1573                ;
1574        return;
1575
1576queue_full:
1577        cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1578        transport_handle_queue_full(cmd, cmd->se_dev);
1579}
1580EXPORT_SYMBOL(transport_generic_request_failure);
1581
1582static void __target_execute_cmd(struct se_cmd *cmd)
1583{
1584        sense_reason_t ret;
1585
1586        spin_lock_irq(&cmd->t_state_lock);
1587        cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
1588        spin_unlock_irq(&cmd->t_state_lock);
1589
1590        if (cmd->execute_cmd) {
1591                ret = cmd->execute_cmd(cmd);
1592                if (ret) {
1593                        spin_lock_irq(&cmd->t_state_lock);
1594                        cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1595                        spin_unlock_irq(&cmd->t_state_lock);
1596
1597                        transport_generic_request_failure(cmd, ret);
1598                }
1599        }
1600}
1601
1602static bool target_handle_task_attr(struct se_cmd *cmd)
1603{
1604        struct se_device *dev = cmd->se_dev;
1605
1606        if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1607                return false;
1608
1609        /*
1610         * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1611         * to allow the passed struct se_cmd list of tasks to the front of the list.
1612         */
1613        switch (cmd->sam_task_attr) {
1614        case MSG_HEAD_TAG:
1615                pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1616                         "se_ordered_id: %u\n",
1617                         cmd->t_task_cdb[0], cmd->se_ordered_id);
1618                return false;
1619        case MSG_ORDERED_TAG:
1620                atomic_inc(&dev->dev_ordered_sync);
1621                smp_mb__after_atomic_inc();
1622
1623                pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1624                         " se_ordered_id: %u\n",
1625                         cmd->t_task_cdb[0], cmd->se_ordered_id);
1626
1627                /*
1628                 * Execute an ORDERED command if no other older commands
1629                 * exist that need to be completed first.
1630                 */
1631                if (!atomic_read(&dev->simple_cmds))
1632                        return false;
1633                break;
1634        default:
1635                /*
1636                 * For SIMPLE and UNTAGGED Task Attribute commands
1637                 */
1638                atomic_inc(&dev->simple_cmds);
1639                smp_mb__after_atomic_inc();
1640                break;
1641        }
1642
1643        if (atomic_read(&dev->dev_ordered_sync) == 0)
1644                return false;
1645
1646        spin_lock(&dev->delayed_cmd_lock);
1647        list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1648        spin_unlock(&dev->delayed_cmd_lock);
1649
1650        pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1651                " delayed CMD list, se_ordered_id: %u\n",
1652                cmd->t_task_cdb[0], cmd->sam_task_attr,
1653                cmd->se_ordered_id);
1654        return true;
1655}
1656
1657void target_execute_cmd(struct se_cmd *cmd)
1658{
1659        /*
1660         * If the received CDB has aleady been aborted stop processing it here.
1661         */
1662        if (transport_check_aborted_status(cmd, 1)) {
1663                complete(&cmd->transport_lun_stop_comp);
1664                return;
1665        }
1666
1667        /*
1668         * Determine if IOCTL context caller in requesting the stopping of this
1669         * command for LUN shutdown purposes.
1670         */
1671        spin_lock_irq(&cmd->t_state_lock);
1672        if (cmd->transport_state & CMD_T_LUN_STOP) {
1673                pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
1674                        __func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
1675
1676                cmd->transport_state &= ~CMD_T_ACTIVE;
1677                spin_unlock_irq(&cmd->t_state_lock);
1678                complete(&cmd->transport_lun_stop_comp);
1679                return;
1680        }
1681        /*
1682         * Determine if frontend context caller is requesting the stopping of
1683         * this command for frontend exceptions.
1684         */
1685        if (cmd->transport_state & CMD_T_STOP) {
1686                pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1687                        __func__, __LINE__,
1688                        cmd->se_tfo->get_task_tag(cmd));
1689
1690                spin_unlock_irq(&cmd->t_state_lock);
1691                complete(&cmd->t_transport_stop_comp);
1692                return;
1693        }
1694
1695        cmd->t_state = TRANSPORT_PROCESSING;
1696        cmd->transport_state |= CMD_T_ACTIVE;
1697        spin_unlock_irq(&cmd->t_state_lock);
1698
1699        if (!target_handle_task_attr(cmd))
1700                __target_execute_cmd(cmd);
1701}
1702EXPORT_SYMBOL(target_execute_cmd);
1703
1704/*
1705 * Process all commands up to the last received ORDERED task attribute which
1706 * requires another blocking boundary
1707 */
1708static void target_restart_delayed_cmds(struct se_device *dev)
1709{
1710        for (;;) {
1711                struct se_cmd *cmd;
1712
1713                spin_lock(&dev->delayed_cmd_lock);
1714                if (list_empty(&dev->delayed_cmd_list)) {
1715                        spin_unlock(&dev->delayed_cmd_lock);
1716                        break;
1717                }
1718
1719                cmd = list_entry(dev->delayed_cmd_list.next,
1720                                 struct se_cmd, se_delayed_node);
1721                list_del(&cmd->se_delayed_node);
1722                spin_unlock(&dev->delayed_cmd_lock);
1723
1724                __target_execute_cmd(cmd);
1725
1726                if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1727                        break;
1728        }
1729}
1730
1731/*
1732 * Called from I/O completion to determine which dormant/delayed
1733 * and ordered cmds need to have their tasks added to the execution queue.
1734 */
1735static void transport_complete_task_attr(struct se_cmd *cmd)
1736{
1737        struct se_device *dev = cmd->se_dev;
1738
1739        if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1740                return;
1741
1742        if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1743                atomic_dec(&dev->simple_cmds);
1744                smp_mb__after_atomic_dec();
1745                dev->dev_cur_ordered_id++;
1746                pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1747                        " SIMPLE: %u\n", dev->dev_cur_ordered_id,
1748                        cmd->se_ordered_id);
1749        } else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1750                dev->dev_cur_ordered_id++;
1751                pr_debug("Incremented dev_cur_ordered_id: %u for"
1752                        " HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1753                        cmd->se_ordered_id);
1754        } else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1755                atomic_dec(&dev->dev_ordered_sync);
1756                smp_mb__after_atomic_dec();
1757
1758                dev->dev_cur_ordered_id++;
1759                pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1760                        " %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1761        }
1762
1763        target_restart_delayed_cmds(dev);
1764}
1765
1766static void transport_complete_qf(struct se_cmd *cmd)
1767{
1768        int ret = 0;
1769
1770        transport_complete_task_attr(cmd);
1771
1772        if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1773                ret = cmd->se_tfo->queue_status(cmd);
1774                if (ret)
1775                        goto out;
1776        }
1777
1778        switch (cmd->data_direction) {
1779        case DMA_FROM_DEVICE:
1780                ret = cmd->se_tfo->queue_data_in(cmd);
1781                break;
1782        case DMA_TO_DEVICE:
1783                if (cmd->t_bidi_data_sg) {
1784                        ret = cmd->se_tfo->queue_data_in(cmd);
1785                        if (ret < 0)
1786                                break;
1787                }
1788                /* Fall through for DMA_TO_DEVICE */
1789        case DMA_NONE:
1790                ret = cmd->se_tfo->queue_status(cmd);
1791                break;
1792        default:
1793                break;
1794        }
1795
1796out:
1797        if (ret < 0) {
1798                transport_handle_queue_full(cmd, cmd->se_dev);
1799                return;
1800        }
1801        transport_lun_remove_cmd(cmd);
1802        transport_cmd_check_stop_to_fabric(cmd);
1803}
1804
1805static void transport_handle_queue_full(
1806        struct se_cmd *cmd,
1807        struct se_device *dev)
1808{
1809        spin_lock_irq(&dev->qf_cmd_lock);
1810        list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1811        atomic_inc(&dev->dev_qf_count);
1812        smp_mb__after_atomic_inc();
1813        spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1814
1815        schedule_work(&cmd->se_dev->qf_work_queue);
1816}
1817
1818static void target_complete_ok_work(struct work_struct *work)
1819{
1820        struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1821        int ret;
1822
1823        /*
1824         * Check if we need to move delayed/dormant tasks from cmds on the
1825         * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1826         * Attribute.
1827         */
1828        transport_complete_task_attr(cmd);
1829
1830        /*
1831         * Check to schedule QUEUE_FULL work, or execute an existing
1832         * cmd->transport_qf_callback()
1833         */
1834        if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1835                schedule_work(&cmd->se_dev->qf_work_queue);
1836
1837        /*
1838         * Check if we need to send a sense buffer from
1839         * the struct se_cmd in question.
1840         */
1841        if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1842                WARN_ON(!cmd->scsi_status);
1843                ret = transport_send_check_condition_and_sense(
1844                                        cmd, 0, 1);
1845                if (ret == -EAGAIN || ret == -ENOMEM)
1846                        goto queue_full;
1847
1848                transport_lun_remove_cmd(cmd);
1849                transport_cmd_check_stop_to_fabric(cmd);
1850                return;
1851        }
1852        /*
1853         * Check for a callback, used by amongst other things
1854         * XDWRITE_READ_10 emulation.
1855         */
1856        if (cmd->transport_complete_callback)
1857                cmd->transport_complete_callback(cmd);
1858
1859        switch (cmd->data_direction) {
1860        case DMA_FROM_DEVICE:
1861                spin_lock(&cmd->se_lun->lun_sep_lock);
1862                if (cmd->se_lun->lun_sep) {
1863                        cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1864                                        cmd->data_length;
1865                }
1866                spin_unlock(&cmd->se_lun->lun_sep_lock);
1867
1868                ret = cmd->se_tfo->queue_data_in(cmd);
1869                if (ret == -EAGAIN || ret == -ENOMEM)
1870                        goto queue_full;
1871                break;
1872        case DMA_TO_DEVICE:
1873                spin_lock(&cmd->se_lun->lun_sep_lock);
1874                if (cmd->se_lun->lun_sep) {
1875                        cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
1876                                cmd->data_length;
1877                }
1878                spin_unlock(&cmd->se_lun->lun_sep_lock);
1879                /*
1880                 * Check if we need to send READ payload for BIDI-COMMAND
1881                 */
1882                if (cmd->t_bidi_data_sg) {
1883                        spin_lock(&cmd->se_lun->lun_sep_lock);
1884                        if (cmd->se_lun->lun_sep) {
1885                                cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1886                                        cmd->data_length;
1887                        }
1888                        spin_unlock(&cmd->se_lun->lun_sep_lock);
1889                        ret = cmd->se_tfo->queue_data_in(cmd);
1890                        if (ret == -EAGAIN || ret == -ENOMEM)
1891                                goto queue_full;
1892                        break;
1893                }
1894                /* Fall through for DMA_TO_DEVICE */
1895        case DMA_NONE:
1896                ret = cmd->se_tfo->queue_status(cmd);
1897                if (ret == -EAGAIN || ret == -ENOMEM)
1898                        goto queue_full;
1899                break;
1900        default:
1901                break;
1902        }
1903
1904        transport_lun_remove_cmd(cmd);
1905        transport_cmd_check_stop_to_fabric(cmd);
1906        return;
1907
1908queue_full:
1909        pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
1910                " data_direction: %d\n", cmd, cmd->data_direction);
1911        cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1912        transport_handle_queue_full(cmd, cmd->se_dev);
1913}
1914
1915static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
1916{
1917        struct scatterlist *sg;
1918        int count;
1919
1920        for_each_sg(sgl, sg, nents, count)
1921                __free_page(sg_page(sg));
1922
1923        kfree(sgl);
1924}
1925
1926static inline void transport_free_pages(struct se_cmd *cmd)
1927{
1928        if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
1929                return;
1930
1931        transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
1932        cmd->t_data_sg = NULL;
1933        cmd->t_data_nents = 0;
1934
1935        transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
1936        cmd->t_bidi_data_sg = NULL;
1937        cmd->t_bidi_data_nents = 0;
1938}
1939
1940/**
1941 * transport_release_cmd - free a command
1942 * @cmd:       command to free
1943 *
1944 * This routine unconditionally frees a command, and reference counting
1945 * or list removal must be done in the caller.
1946 */
1947static int transport_release_cmd(struct se_cmd *cmd)
1948{
1949        BUG_ON(!cmd->se_tfo);
1950
1951        if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1952                core_tmr_release_req(cmd->se_tmr_req);
1953        if (cmd->t_task_cdb != cmd->__t_task_cdb)
1954                kfree(cmd->t_task_cdb);
1955        /*
1956         * If this cmd has been setup with target_get_sess_cmd(), drop
1957         * the kref and call ->release_cmd() in kref callback.
1958         */
1959         if (cmd->check_release != 0)
1960                return target_put_sess_cmd(cmd->se_sess, cmd);
1961
1962        cmd->se_tfo->release_cmd(cmd);
1963        return 1;
1964}
1965
1966/**
1967 * transport_put_cmd - release a reference to a command
1968 * @cmd:       command to release
1969 *
1970 * This routine releases our reference to the command and frees it if possible.
1971 */
1972static int transport_put_cmd(struct se_cmd *cmd)
1973{
1974        unsigned long flags;
1975
1976        spin_lock_irqsave(&cmd->t_state_lock, flags);
1977        if (atomic_read(&cmd->t_fe_count) &&
1978            !atomic_dec_and_test(&cmd->t_fe_count)) {
1979                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1980                return 0;
1981        }
1982
1983        if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
1984                cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
1985                target_remove_from_state_list(cmd);
1986        }
1987        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1988
1989        transport_free_pages(cmd);
1990        return transport_release_cmd(cmd);
1991}
1992
1993void *transport_kmap_data_sg(struct se_cmd *cmd)
1994{
1995        struct scatterlist *sg = cmd->t_data_sg;
1996        struct page **pages;
1997        int i;
1998
1999        /*
2000         * We need to take into account a possible offset here for fabrics like
2001         * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2002         * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2003         */
2004        if (!cmd->t_data_nents)
2005                return NULL;
2006
2007        BUG_ON(!sg);
2008        if (cmd->t_data_nents == 1)
2009                return kmap(sg_page(sg)) + sg->offset;
2010
2011        /* >1 page. use vmap */
2012        pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2013        if (!pages)
2014                return NULL;
2015
2016        /* convert sg[] to pages[] */
2017        for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2018                pages[i] = sg_page(sg);
2019        }
2020
2021        cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2022        kfree(pages);
2023        if (!cmd->t_data_vmap)
2024                return NULL;
2025
2026        return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2027}
2028EXPORT_SYMBOL(transport_kmap_data_sg);
2029
2030void transport_kunmap_data_sg(struct se_cmd *cmd)
2031{
2032        if (!cmd->t_data_nents) {
2033                return;
2034        } else if (cmd->t_data_nents == 1) {
2035                kunmap(sg_page(cmd->t_data_sg));
2036                return;
2037        }
2038
2039        vunmap(cmd->t_data_vmap);
2040        cmd->t_data_vmap = NULL;
2041}
2042EXPORT_SYMBOL(transport_kunmap_data_sg);
2043
2044static int
2045transport_generic_get_mem(struct se_cmd *cmd)
2046{
2047        u32 length = cmd->data_length;
2048        unsigned int nents;
2049        struct page *page;
2050        gfp_t zero_flag;
2051        int i = 0;
2052
2053        nents = DIV_ROUND_UP(length, PAGE_SIZE);
2054        cmd->t_data_sg = kmalloc(sizeof(struct scatterlist) * nents, GFP_KERNEL);
2055        if (!cmd->t_data_sg)
2056                return -ENOMEM;
2057
2058        cmd->t_data_nents = nents;
2059        sg_init_table(cmd->t_data_sg, nents);
2060
2061        zero_flag = cmd->se_cmd_flags & SCF_SCSI_DATA_CDB ? 0 : __GFP_ZERO;
2062
2063        while (length) {
2064                u32 page_len = min_t(u32, length, PAGE_SIZE);
2065                page = alloc_page(GFP_KERNEL | zero_flag);
2066                if (!page)
2067                        goto out;
2068
2069                sg_set_page(&cmd->t_data_sg[i], page, page_len, 0);
2070                length -= page_len;
2071                i++;
2072        }
2073        return 0;
2074
2075out:
2076        while (i > 0) {
2077                i--;
2078                __free_page(sg_page(&cmd->t_data_sg[i]));
2079        }
2080        kfree(cmd->t_data_sg);
2081        cmd->t_data_sg = NULL;
2082        return -ENOMEM;
2083}
2084
2085/*
2086 * Allocate any required resources to execute the command.  For writes we
2087 * might not have the payload yet, so notify the fabric via a call to
2088 * ->write_pending instead. Otherwise place it on the execution queue.
2089 */
2090sense_reason_t
2091transport_generic_new_cmd(struct se_cmd *cmd)
2092{
2093        int ret = 0;
2094
2095        /*
2096         * Determine is the TCM fabric module has already allocated physical
2097         * memory, and is directly calling transport_generic_map_mem_to_cmd()
2098         * beforehand.
2099         */
2100        if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2101            cmd->data_length) {
2102                ret = transport_generic_get_mem(cmd);
2103                if (ret < 0)
2104                        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2105        }
2106
2107        atomic_inc(&cmd->t_fe_count);
2108
2109        /*
2110         * If this command is not a write we can execute it right here,
2111         * for write buffers we need to notify the fabric driver first
2112         * and let it call back once the write buffers are ready.
2113         */
2114        target_add_to_state_list(cmd);
2115        if (cmd->data_direction != DMA_TO_DEVICE) {
2116                target_execute_cmd(cmd);
2117                return 0;
2118        }
2119
2120        spin_lock_irq(&cmd->t_state_lock);
2121        cmd->t_state = TRANSPORT_WRITE_PENDING;
2122        spin_unlock_irq(&cmd->t_state_lock);
2123
2124        transport_cmd_check_stop(cmd, false);
2125
2126        ret = cmd->se_tfo->write_pending(cmd);
2127        if (ret == -EAGAIN || ret == -ENOMEM)
2128                goto queue_full;
2129
2130        /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2131        WARN_ON(ret);
2132
2133        return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2134
2135queue_full:
2136        pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2137        cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2138        transport_handle_queue_full(cmd, cmd->se_dev);
2139        return 0;
2140}
2141EXPORT_SYMBOL(transport_generic_new_cmd);
2142
2143static void transport_write_pending_qf(struct se_cmd *cmd)
2144{
2145        int ret;
2146
2147        ret = cmd->se_tfo->write_pending(cmd);
2148        if (ret == -EAGAIN || ret == -ENOMEM) {
2149                pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2150                         cmd);
2151                transport_handle_queue_full(cmd, cmd->se_dev);
2152        }
2153}
2154
2155int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2156{
2157        int ret = 0;
2158
2159        if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2160                if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2161                         transport_wait_for_tasks(cmd);
2162
2163                ret = transport_release_cmd(cmd);
2164        } else {
2165                if (wait_for_tasks)
2166                        transport_wait_for_tasks(cmd);
2167
2168                if (cmd->se_lun)
2169                        transport_lun_remove_cmd(cmd);
2170
2171                ret = transport_put_cmd(cmd);
2172        }
2173        return ret;
2174}
2175EXPORT_SYMBOL(transport_generic_free_cmd);
2176
2177/* target_get_sess_cmd - Add command to active ->sess_cmd_list
2178 * @se_sess:    session to reference
2179 * @se_cmd:     command descriptor to add
2180 * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2181 */
2182int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2183                               bool ack_kref)
2184{
2185        unsigned long flags;
2186        int ret = 0;
2187
2188        kref_init(&se_cmd->cmd_kref);
2189        /*
2190         * Add a second kref if the fabric caller is expecting to handle
2191         * fabric acknowledgement that requires two target_put_sess_cmd()
2192         * invocations before se_cmd descriptor release.
2193         */
2194        if (ack_kref == true) {
2195                kref_get(&se_cmd->cmd_kref);
2196                se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2197        }
2198
2199        spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2200        if (se_sess->sess_tearing_down) {
2201                ret = -ESHUTDOWN;
2202                goto out;
2203        }
2204        list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2205        se_cmd->check_release = 1;
2206
2207out:
2208        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2209        return ret;
2210}
2211EXPORT_SYMBOL(target_get_sess_cmd);
2212
2213static void target_release_cmd_kref(struct kref *kref)
2214{
2215        struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2216        struct se_session *se_sess = se_cmd->se_sess;
2217
2218        if (list_empty(&se_cmd->se_cmd_list)) {
2219                spin_unlock(&se_sess->sess_cmd_lock);
2220                se_cmd->se_tfo->release_cmd(se_cmd);
2221                return;
2222        }
2223        if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2224                spin_unlock(&se_sess->sess_cmd_lock);
2225                complete(&se_cmd->cmd_wait_comp);
2226                return;
2227        }
2228        list_del(&se_cmd->se_cmd_list);
2229        spin_unlock(&se_sess->sess_cmd_lock);
2230
2231        se_cmd->se_tfo->release_cmd(se_cmd);
2232}
2233
2234/* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2235 * @se_sess:    session to reference
2236 * @se_cmd:     command descriptor to drop
2237 */
2238int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2239{
2240        return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2241                        &se_sess->sess_cmd_lock);
2242}
2243EXPORT_SYMBOL(target_put_sess_cmd);
2244
2245/* target_sess_cmd_list_set_waiting - Flag all commands in
2246 *         sess_cmd_list to complete cmd_wait_comp.  Set
2247 *         sess_tearing_down so no more commands are queued.
2248 * @se_sess:    session to flag
2249 */
2250void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2251{
2252        struct se_cmd *se_cmd;
2253        unsigned long flags;
2254
2255        spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2256        if (se_sess->sess_tearing_down) {
2257                spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2258                return;
2259        }
2260        se_sess->sess_tearing_down = 1;
2261        list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2262
2263        list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2264                se_cmd->cmd_wait_set = 1;
2265
2266        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2267}
2268EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2269
2270/* target_wait_for_sess_cmds - Wait for outstanding descriptors
2271 * @se_sess:    session to wait for active I/O
2272 */
2273void target_wait_for_sess_cmds(struct se_session *se_sess)
2274{
2275        struct se_cmd *se_cmd, *tmp_cmd;
2276        unsigned long flags;
2277
2278        list_for_each_entry_safe(se_cmd, tmp_cmd,
2279                                &se_sess->sess_wait_list, se_cmd_list) {
2280                list_del(&se_cmd->se_cmd_list);
2281
2282                pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2283                        " %d\n", se_cmd, se_cmd->t_state,
2284                        se_cmd->se_tfo->get_cmd_state(se_cmd));
2285
2286                wait_for_completion(&se_cmd->cmd_wait_comp);
2287                pr_debug("After cmd_wait_comp: 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                se_cmd->se_tfo->release_cmd(se_cmd);
2292        }
2293
2294        spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2295        WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2296        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2297
2298}
2299EXPORT_SYMBOL(target_wait_for_sess_cmds);
2300
2301/*      transport_lun_wait_for_tasks():
2302 *
2303 *      Called from ConfigFS context to stop the passed struct se_cmd to allow
2304 *      an struct se_lun to be successfully shutdown.
2305 */
2306static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
2307{
2308        unsigned long flags;
2309        int ret = 0;
2310
2311        /*
2312         * If the frontend has already requested this struct se_cmd to
2313         * be stopped, we can safely ignore this struct se_cmd.
2314         */
2315        spin_lock_irqsave(&cmd->t_state_lock, flags);
2316        if (cmd->transport_state & CMD_T_STOP) {
2317                cmd->transport_state &= ~CMD_T_LUN_STOP;
2318
2319                pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
2320                         cmd->se_tfo->get_task_tag(cmd));
2321                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2322                transport_cmd_check_stop(cmd, false);
2323                return -EPERM;
2324        }
2325        cmd->transport_state |= CMD_T_LUN_FE_STOP;
2326        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2327
2328        // XXX: audit task_flags checks.
2329        spin_lock_irqsave(&cmd->t_state_lock, flags);
2330        if ((cmd->transport_state & CMD_T_BUSY) &&
2331            (cmd->transport_state & CMD_T_SENT)) {
2332                if (!target_stop_cmd(cmd, &flags))
2333                        ret++;
2334        }
2335        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2336
2337        pr_debug("ConfigFS: cmd: %p stop tasks ret:"
2338                        " %d\n", cmd, ret);
2339        if (!ret) {
2340                pr_debug("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
2341                                cmd->se_tfo->get_task_tag(cmd));
2342                wait_for_completion(&cmd->transport_lun_stop_comp);
2343                pr_debug("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
2344                                cmd->se_tfo->get_task_tag(cmd));
2345        }
2346
2347        return 0;
2348}
2349
2350static void __transport_clear_lun_from_sessions(struct se_lun *lun)
2351{
2352        struct se_cmd *cmd = NULL;
2353        unsigned long lun_flags, cmd_flags;
2354        /*
2355         * Do exception processing and return CHECK_CONDITION status to the
2356         * Initiator Port.
2357         */
2358        spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2359        while (!list_empty(&lun->lun_cmd_list)) {
2360                cmd = list_first_entry(&lun->lun_cmd_list,
2361                       struct se_cmd, se_lun_node);
2362                list_del_init(&cmd->se_lun_node);
2363
2364                spin_lock(&cmd->t_state_lock);
2365                pr_debug("SE_LUN[%d] - Setting cmd->transport"
2366                        "_lun_stop for  ITT: 0x%08x\n",
2367                        cmd->se_lun->unpacked_lun,
2368                        cmd->se_tfo->get_task_tag(cmd));
2369                cmd->transport_state |= CMD_T_LUN_STOP;
2370                spin_unlock(&cmd->t_state_lock);
2371
2372                spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2373
2374                if (!cmd->se_lun) {
2375                        pr_err("ITT: 0x%08x, [i,t]_state: %u/%u\n",
2376                                cmd->se_tfo->get_task_tag(cmd),
2377                                cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2378                        BUG();
2379                }
2380                /*
2381                 * If the Storage engine still owns the iscsi_cmd_t, determine
2382                 * and/or stop its context.
2383                 */
2384                pr_debug("SE_LUN[%d] - ITT: 0x%08x before transport"
2385                        "_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
2386                        cmd->se_tfo->get_task_tag(cmd));
2387
2388                if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
2389                        spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2390                        continue;
2391                }
2392
2393                pr_debug("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
2394                        "_wait_for_tasks(): SUCCESS\n",
2395                        cmd->se_lun->unpacked_lun,
2396                        cmd->se_tfo->get_task_tag(cmd));
2397
2398                spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2399                if (!(cmd->transport_state & CMD_T_DEV_ACTIVE)) {
2400                        spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2401                        goto check_cond;
2402                }
2403                cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2404                target_remove_from_state_list(cmd);
2405                spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2406
2407                /*
2408                 * The Storage engine stopped this struct se_cmd before it was
2409                 * send to the fabric frontend for delivery back to the
2410                 * Initiator Node.  Return this SCSI CDB back with an
2411                 * CHECK_CONDITION status.
2412                 */
2413check_cond:
2414                transport_send_check_condition_and_sense(cmd,
2415                                TCM_NON_EXISTENT_LUN, 0);
2416                /*
2417                 *  If the fabric frontend is waiting for this iscsi_cmd_t to
2418                 * be released, notify the waiting thread now that LU has
2419                 * finished accessing it.
2420                 */
2421                spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2422                if (cmd->transport_state & CMD_T_LUN_FE_STOP) {
2423                        pr_debug("SE_LUN[%d] - Detected FE stop for"
2424                                " struct se_cmd: %p ITT: 0x%08x\n",
2425                                lun->unpacked_lun,
2426                                cmd, cmd->se_tfo->get_task_tag(cmd));
2427
2428                        spin_unlock_irqrestore(&cmd->t_state_lock,
2429                                        cmd_flags);
2430                        transport_cmd_check_stop(cmd, false);
2431                        complete(&cmd->transport_lun_fe_stop_comp);
2432                        spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2433                        continue;
2434                }
2435                pr_debug("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
2436                        lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));
2437
2438                spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2439                spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2440        }
2441        spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2442}
2443
2444static int transport_clear_lun_thread(void *p)
2445{
2446        struct se_lun *lun = p;
2447
2448        __transport_clear_lun_from_sessions(lun);
2449        complete(&lun->lun_shutdown_comp);
2450
2451        return 0;
2452}
2453
2454int transport_clear_lun_from_sessions(struct se_lun *lun)
2455{
2456        struct task_struct *kt;
2457
2458        kt = kthread_run(transport_clear_lun_thread, lun,
2459                        "tcm_cl_%u", lun->unpacked_lun);
2460        if (IS_ERR(kt)) {
2461                pr_err("Unable to start clear_lun thread\n");
2462                return PTR_ERR(kt);
2463        }
2464        wait_for_completion(&lun->lun_shutdown_comp);
2465
2466        return 0;
2467}
2468
2469/**
2470 * transport_wait_for_tasks - wait for completion to occur
2471 * @cmd:        command to wait
2472 *
2473 * Called from frontend fabric context to wait for storage engine
2474 * to pause and/or release frontend generated struct se_cmd.
2475 */
2476bool transport_wait_for_tasks(struct se_cmd *cmd)
2477{
2478        unsigned long flags;
2479
2480        spin_lock_irqsave(&cmd->t_state_lock, flags);
2481        if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2482            !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2483                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2484                return false;
2485        }
2486
2487        if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2488            !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2489                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2490                return false;
2491        }
2492        /*
2493         * If we are already stopped due to an external event (ie: LUN shutdown)
2494         * sleep until the connection can have the passed struct se_cmd back.
2495         * The cmd->transport_lun_stopped_sem will be upped by
2496         * transport_clear_lun_from_sessions() once the ConfigFS context caller
2497         * has completed its operation on the struct se_cmd.
2498         */
2499        if (cmd->transport_state & CMD_T_LUN_STOP) {
2500                pr_debug("wait_for_tasks: Stopping"
2501                        " wait_for_completion(&cmd->t_tasktransport_lun_fe"
2502                        "_stop_comp); for ITT: 0x%08x\n",
2503                        cmd->se_tfo->get_task_tag(cmd));
2504                /*
2505                 * There is a special case for WRITES where a FE exception +
2506                 * LUN shutdown means ConfigFS context is still sleeping on
2507                 * transport_lun_stop_comp in transport_lun_wait_for_tasks().
2508                 * We go ahead and up transport_lun_stop_comp just to be sure
2509                 * here.
2510                 */
2511                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2512                complete(&cmd->transport_lun_stop_comp);
2513                wait_for_completion(&cmd->transport_lun_fe_stop_comp);
2514                spin_lock_irqsave(&cmd->t_state_lock, flags);
2515
2516                target_remove_from_state_list(cmd);
2517                /*
2518                 * At this point, the frontend who was the originator of this
2519                 * struct se_cmd, now owns the structure and can be released through
2520                 * normal means below.
2521                 */
2522                pr_debug("wait_for_tasks: Stopped"
2523                        " wait_for_completion(&cmd->t_tasktransport_lun_fe_"
2524                        "stop_comp); for ITT: 0x%08x\n",
2525                        cmd->se_tfo->get_task_tag(cmd));
2526
2527                cmd->transport_state &= ~CMD_T_LUN_STOP;
2528        }
2529
2530        if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2531                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2532                return false;
2533        }
2534
2535        cmd->transport_state |= CMD_T_STOP;
2536
2537        pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2538                " i_state: %d, t_state: %d, CMD_T_STOP\n",
2539                cmd, cmd->se_tfo->get_task_tag(cmd),
2540                cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2541
2542        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2543
2544        wait_for_completion(&cmd->t_transport_stop_comp);
2545
2546        spin_lock_irqsave(&cmd->t_state_lock, flags);
2547        cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2548
2549        pr_debug("wait_for_tasks: Stopped wait_for_completion("
2550                "&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2551                cmd->se_tfo->get_task_tag(cmd));
2552
2553        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2554
2555        return true;
2556}
2557EXPORT_SYMBOL(transport_wait_for_tasks);
2558
2559static int transport_get_sense_codes(
2560        struct se_cmd *cmd,
2561        u8 *asc,
2562        u8 *ascq)
2563{
2564        *asc = cmd->scsi_asc;
2565        *ascq = cmd->scsi_ascq;
2566
2567        return 0;
2568}
2569
2570int
2571transport_send_check_condition_and_sense(struct se_cmd *cmd,
2572                sense_reason_t reason, int from_transport)
2573{
2574        unsigned char *buffer = cmd->sense_buffer;
2575        unsigned long flags;
2576        u8 asc = 0, ascq = 0;
2577
2578        spin_lock_irqsave(&cmd->t_state_lock, flags);
2579        if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2580                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2581                return 0;
2582        }
2583        cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2584        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2585
2586        if (!reason && from_transport)
2587                goto after_reason;
2588
2589        if (!from_transport)
2590                cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2591
2592        /*
2593         * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2594         * SENSE KEY values from include/scsi/scsi.h
2595         */
2596        switch (reason) {
2597        case TCM_NO_SENSE:
2598                /* CURRENT ERROR */
2599                buffer[0] = 0x70;
2600                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2601                /* Not Ready */
2602                buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2603                /* NO ADDITIONAL SENSE INFORMATION */
2604                buffer[SPC_ASC_KEY_OFFSET] = 0;
2605                buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2606                break;
2607        case TCM_NON_EXISTENT_LUN:
2608                /* CURRENT ERROR */
2609                buffer[0] = 0x70;
2610                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2611                /* ILLEGAL REQUEST */
2612                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2613                /* LOGICAL UNIT NOT SUPPORTED */
2614                buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2615                break;
2616        case TCM_UNSUPPORTED_SCSI_OPCODE:
2617        case TCM_SECTOR_COUNT_TOO_MANY:
2618                /* CURRENT ERROR */
2619                buffer[0] = 0x70;
2620                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2621                /* ILLEGAL REQUEST */
2622                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2623                /* INVALID COMMAND OPERATION CODE */
2624                buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2625                break;
2626        case TCM_UNKNOWN_MODE_PAGE:
2627                /* CURRENT ERROR */
2628                buffer[0] = 0x70;
2629                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2630                /* ILLEGAL REQUEST */
2631                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2632                /* INVALID FIELD IN CDB */
2633                buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2634                break;
2635        case TCM_CHECK_CONDITION_ABORT_CMD:
2636                /* CURRENT ERROR */
2637                buffer[0] = 0x70;
2638                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2639                /* ABORTED COMMAND */
2640                buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2641                /* BUS DEVICE RESET FUNCTION OCCURRED */
2642                buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2643                buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2644                break;
2645        case TCM_INCORRECT_AMOUNT_OF_DATA:
2646                /* CURRENT ERROR */
2647                buffer[0] = 0x70;
2648                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2649                /* ABORTED COMMAND */
2650                buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2651                /* WRITE ERROR */
2652                buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2653                /* NOT ENOUGH UNSOLICITED DATA */
2654                buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2655                break;
2656        case TCM_INVALID_CDB_FIELD:
2657                /* CURRENT ERROR */
2658                buffer[0] = 0x70;
2659                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2660                /* ILLEGAL REQUEST */
2661                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2662                /* INVALID FIELD IN CDB */
2663                buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2664                break;
2665        case TCM_INVALID_PARAMETER_LIST:
2666                /* CURRENT ERROR */
2667                buffer[0] = 0x70;
2668                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2669                /* ILLEGAL REQUEST */
2670                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2671                /* INVALID FIELD IN PARAMETER LIST */
2672                buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2673                break;
2674        case TCM_PARAMETER_LIST_LENGTH_ERROR:
2675                /* CURRENT ERROR */
2676                buffer[0] = 0x70;
2677                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2678                /* ILLEGAL REQUEST */
2679                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2680                /* PARAMETER LIST LENGTH ERROR */
2681                buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2682                break;
2683        case TCM_UNEXPECTED_UNSOLICITED_DATA:
2684                /* CURRENT ERROR */
2685                buffer[0] = 0x70;
2686                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2687                /* ABORTED COMMAND */
2688                buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2689                /* WRITE ERROR */
2690                buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2691                /* UNEXPECTED_UNSOLICITED_DATA */
2692                buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2693                break;
2694        case TCM_SERVICE_CRC_ERROR:
2695                /* CURRENT ERROR */
2696                buffer[0] = 0x70;
2697                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2698                /* ABORTED COMMAND */
2699                buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2700                /* PROTOCOL SERVICE CRC ERROR */
2701                buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2702                /* N/A */
2703                buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2704                break;
2705        case TCM_SNACK_REJECTED:
2706                /* CURRENT ERROR */
2707                buffer[0] = 0x70;
2708                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2709                /* ABORTED COMMAND */
2710                buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2711                /* READ ERROR */
2712                buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2713                /* FAILED RETRANSMISSION REQUEST */
2714                buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2715                break;
2716        case TCM_WRITE_PROTECTED:
2717                /* CURRENT ERROR */
2718                buffer[0] = 0x70;
2719                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2720                /* DATA PROTECT */
2721                buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2722                /* WRITE PROTECTED */
2723                buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2724                break;
2725        case TCM_ADDRESS_OUT_OF_RANGE:
2726                /* CURRENT ERROR */
2727                buffer[0] = 0x70;
2728                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2729                /* ILLEGAL REQUEST */
2730                buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2731                /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2732                buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2733                break;
2734        case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2735                /* CURRENT ERROR */
2736                buffer[0] = 0x70;
2737                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2738                /* UNIT ATTENTION */
2739                buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2740                core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2741                buffer[SPC_ASC_KEY_OFFSET] = asc;
2742                buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2743                break;
2744        case TCM_CHECK_CONDITION_NOT_READY:
2745                /* CURRENT ERROR */
2746                buffer[0] = 0x70;
2747                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2748                /* Not Ready */
2749                buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2750                transport_get_sense_codes(cmd, &asc, &ascq);
2751                buffer[SPC_ASC_KEY_OFFSET] = asc;
2752                buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2753                break;
2754        case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2755        default:
2756                /* CURRENT ERROR */
2757                buffer[0] = 0x70;
2758                buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2759                /*
2760                 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2761                 * Solaris initiators.  Returning NOT READY instead means the
2762                 * operations will be retried a finite number of times and we
2763                 * can survive intermittent errors.
2764                 */
2765                buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2766                /* LOGICAL UNIT COMMUNICATION FAILURE */
2767                buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2768                break;
2769        }
2770        /*
2771         * This code uses linux/include/scsi/scsi.h SAM status codes!
2772         */
2773        cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2774        /*
2775         * Automatically padded, this value is encoded in the fabric's
2776         * data_length response PDU containing the SCSI defined sense data.
2777         */
2778        cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2779
2780after_reason:
2781        return cmd->se_tfo->queue_status(cmd);
2782}
2783EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2784
2785int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2786{
2787        if (!(cmd->transport_state & CMD_T_ABORTED))
2788                return 0;
2789
2790        if (!send_status || (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
2791                return 1;
2792
2793        pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2794                 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2795
2796        cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
2797        cmd->se_tfo->queue_status(cmd);
2798
2799        return 1;
2800}
2801EXPORT_SYMBOL(transport_check_aborted_status);
2802
2803void transport_send_task_abort(struct se_cmd *cmd)
2804{
2805        unsigned long flags;
2806
2807        spin_lock_irqsave(&cmd->t_state_lock, flags);
2808        if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION | SCF_SENT_DELAYED_TAS)) {
2809                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2810                return;
2811        }
2812        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2813
2814        /*
2815         * If there are still expected incoming fabric WRITEs, we wait
2816         * until until they have completed before sending a TASK_ABORTED
2817         * response.  This response with TASK_ABORTED status will be
2818         * queued back to fabric module by transport_check_aborted_status().
2819         */
2820        if (cmd->data_direction == DMA_TO_DEVICE) {
2821                if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2822                        cmd->transport_state |= CMD_T_ABORTED;
2823                        smp_mb__after_atomic_inc();
2824                }
2825        }
2826        cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2827
2828        transport_lun_remove_cmd(cmd);
2829
2830        pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2831                " ITT: 0x%08x\n", cmd->t_task_cdb[0],
2832                cmd->se_tfo->get_task_tag(cmd));
2833
2834        cmd->se_tfo->queue_status(cmd);
2835}
2836
2837static void target_tmr_work(struct work_struct *work)
2838{
2839        struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2840        struct se_device *dev = cmd->se_dev;
2841        struct se_tmr_req *tmr = cmd->se_tmr_req;
2842        int ret;
2843
2844        switch (tmr->function) {
2845        case TMR_ABORT_TASK:
2846                core_tmr_abort_task(dev, tmr, cmd->se_sess);
2847                break;
2848        case TMR_ABORT_TASK_SET:
2849        case TMR_CLEAR_ACA:
2850        case TMR_CLEAR_TASK_SET:
2851                tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2852                break;
2853        case TMR_LUN_RESET:
2854                ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2855                tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2856                                         TMR_FUNCTION_REJECTED;
2857                break;
2858        case TMR_TARGET_WARM_RESET:
2859                tmr->response = TMR_FUNCTION_REJECTED;
2860                break;
2861        case TMR_TARGET_COLD_RESET:
2862                tmr->response = TMR_FUNCTION_REJECTED;
2863                break;
2864        default:
2865                pr_err("Uknown TMR function: 0x%02x.\n",
2866                                tmr->function);
2867                tmr->response = TMR_FUNCTION_REJECTED;
2868                break;
2869        }
2870
2871        cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2872        cmd->se_tfo->queue_tm_rsp(cmd);
2873
2874        transport_cmd_check_stop_to_fabric(cmd);
2875}
2876
2877int transport_generic_handle_tmr(
2878        struct se_cmd *cmd)
2879{
2880        INIT_WORK(&cmd->work, target_tmr_work);
2881        queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2882        return 0;
2883}
2884EXPORT_SYMBOL(transport_generic_handle_tmr);
2885
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