drivers/target/target_core_transport.c

   1 /*******************************************************************************
   2  * Filename:  target_core_transport.c
   3  *
   4  * This file contains the Generic Target Engine Core.
   5  *
   6  * (c) Copyright 2002-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <[email protected]>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/net.h>
  27 #include <linux/delay.h>
  28 #include <linux/string.h>
  29 #include <linux/timer.h>
  30 #include <linux/slab.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/kthread.h>
  33 #include <linux/in.h>
  34 #include <linux/cdrom.h>
  35 #include <linux/module.h>
  36 #include <linux/ratelimit.h>
  37 #include <asm/unaligned.h>
  38 #include <net/sock.h>
  39 #include <net/tcp.h>
  40 #include <scsi/scsi.h>
  41 #include <scsi/scsi_cmnd.h>
  42 #include <scsi/scsi_tcq.h>
  43
  44 #include <target/target_core_base.h>
  45 #include <target/target_core_backend.h>
  46 #include <target/target_core_fabric.h>
  47 #include <target/target_core_configfs.h>
  48
  49 #include "target_core_internal.h"
  50 #include "target_core_alua.h"
  51 #include "target_core_pr.h"
  52 #include "target_core_ua.h"
  53
  54 #define CREATE_TRACE_POINTS
  55 #include <trace/events/target.h>
  56
  57 static struct workqueue_struct *target_completion_wq;
  58 static struct kmem_cache *se_sess_cache;
  59 struct kmem_cache *se_ua_cache;
  60 struct kmem_cache *t10_pr_reg_cache;
  61 struct kmem_cache *t10_alua_lu_gp_cache;
  62 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  63 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  64 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
  65
  66 static void transport_complete_task_attr(struct se_cmd *cmd);
  67 static void transport_handle_queue_full(struct se_cmd *cmd,
  68                 struct se_device *dev);
  69 static int transport_put_cmd(struct se_cmd *cmd);
  70 static void target_complete_ok_work(struct work_struct *work);
  71
  72 int init_se_kmem_caches(void)
  73 {
  74         se_sess_cache = kmem_cache_create("se_sess_cache",
  75                         sizeof(struct se_session), __alignof__(struct se_session),
  76                         0, NULL);
  77         if (!se_sess_cache) {
  78                 pr_err("kmem_cache_create() for struct se_session"
  79                                 " failed\n");
  80                 goto out;
  81         }
  82         se_ua_cache = kmem_cache_create("se_ua_cache",
  83                         sizeof(struct se_ua), __alignof__(struct se_ua),
  84                         0, NULL);
  85         if (!se_ua_cache) {
  86                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  87                 goto out_free_sess_cache;
  88         }
  89         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  90                         sizeof(struct t10_pr_registration),
  91                         __alignof__(struct t10_pr_registration), 0, NULL);
  92         if (!t10_pr_reg_cache) {
  93                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  94                                 " failed\n");
  95                 goto out_free_ua_cache;
  96         }
  97         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  98                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  99                         0, NULL);
 100         if (!t10_alua_lu_gp_cache) {
 101                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 102                                 " failed\n");
 103                 goto out_free_pr_reg_cache;
 104         }
 105         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 106                         sizeof(struct t10_alua_lu_gp_member),
 107                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 108         if (!t10_alua_lu_gp_mem_cache) {
 109                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 110                                 "cache failed\n");
 111                 goto out_free_lu_gp_cache;
 112         }
 113         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 114                         sizeof(struct t10_alua_tg_pt_gp),
 115                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 116         if (!t10_alua_tg_pt_gp_cache) {
 117                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 118                                 "cache failed\n");
 119                 goto out_free_lu_gp_mem_cache;
 120         }
 121         t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
 122                         "t10_alua_tg_pt_gp_mem_cache",
 123                         sizeof(struct t10_alua_tg_pt_gp_member),
 124                         __alignof__(struct t10_alua_tg_pt_gp_member),
 125                         0, NULL);
 126         if (!t10_alua_tg_pt_gp_mem_cache) {
 127                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 128                                 "mem_t failed\n");
 129                 goto out_free_tg_pt_gp_cache;
 130         }
 131
 132         target_completion_wq = alloc_workqueue("target_completion",
 133                                                WQ_MEM_RECLAIM, 0);
 134         if (!target_completion_wq)
 135                 goto out_free_tg_pt_gp_mem_cache;
 136
 137         return 0;
 138
 139 out_free_tg_pt_gp_mem_cache:
 140         kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 141 out_free_tg_pt_gp_cache:
 142         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 143 out_free_lu_gp_mem_cache:
 144         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 145 out_free_lu_gp_cache:
 146         kmem_cache_destroy(t10_alua_lu_gp_cache);
 147 out_free_pr_reg_cache:
 148         kmem_cache_destroy(t10_pr_reg_cache);
 149 out_free_ua_cache:
 150         kmem_cache_destroy(se_ua_cache);
 151 out_free_sess_cache:
 152         kmem_cache_destroy(se_sess_cache);
 153 out:
 154         return -ENOMEM;
 155 }
 156
 157 void release_se_kmem_caches(void)
 158 {
 159         destroy_workqueue(target_completion_wq);
 160         kmem_cache_destroy(se_sess_cache);
 161         kmem_cache_destroy(se_ua_cache);
 162         kmem_cache_destroy(t10_pr_reg_cache);
 163         kmem_cache_destroy(t10_alua_lu_gp_cache);
 164         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 165         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 166         kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 167 }
 168
 169 /* This code ensures unique mib indexes are handed out. */
 170 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 171 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 172
 173 /*
 174  * Allocate a new row index for the entry type specified
 175  */
 176 u32 scsi_get_new_index(scsi_index_t type)
 177 {
 178         u32 new_index;
 179
 180         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 181
 182         spin_lock(&scsi_mib_index_lock);
 183         new_index = ++scsi_mib_index[type];
 184         spin_unlock(&scsi_mib_index_lock);
 185
 186         return new_index;
 187 }
 188
 189 void transport_subsystem_check_init(void)
 190 {
 191         int ret;
 192         static int sub_api_initialized;
 193
 194         if (sub_api_initialized)
 195                 return;
 196
 197         ret = request_module("target_core_iblock");
 198         if (ret != 0)
 199                 pr_err("Unable to load target_core_iblock\n");
 200
 201         ret = request_module("target_core_file");
 202         if (ret != 0)
 203                 pr_err("Unable to load target_core_file\n");
 204
 205         ret = request_module("target_core_pscsi");
 206         if (ret != 0)
 207                 pr_err("Unable to load target_core_pscsi\n");
 208
 209         sub_api_initialized = 1;
 210 }
 211
 212 struct se_session *transport_init_session(void)
 213 {
 214         struct se_session *se_sess;
 215
 216         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 217         if (!se_sess) {
 218                 pr_err("Unable to allocate struct se_session from"
 219                                 " se_sess_cache\n");
 220                 return ERR_PTR(-ENOMEM);
 221         }
 222         INIT_LIST_HEAD(&se_sess->sess_list);
 223         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 224         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 225         INIT_LIST_HEAD(&se_sess->sess_wait_list);
 226         spin_lock_init(&se_sess->sess_cmd_lock);
 227         kref_init(&se_sess->sess_kref);
 228
 229         return se_sess;
 230 }
 231 EXPORT_SYMBOL(transport_init_session);
 232
 233 int transport_alloc_session_tags(struct se_session *se_sess,
 234                                  unsigned int tag_num, unsigned int tag_size)
 235 {
 236         int rc;
 237
 238         se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
 239                                         GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
 240         if (!se_sess->sess_cmd_map) {
 241                 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
 242                 if (!se_sess->sess_cmd_map) {
 243                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 244                         return -ENOMEM;
 245                 }
 246         }
 247
 248         rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
 249         if (rc < 0) {
 250                 pr_err("Unable to init se_sess->sess_tag_pool,"
 251                         " tag_num: %u\n", tag_num);
 252                 if (is_vmalloc_addr(se_sess->sess_cmd_map))
 253                         vfree(se_sess->sess_cmd_map);
 254                 else
 255                         kfree(se_sess->sess_cmd_map);
 256                 se_sess->sess_cmd_map = NULL;
 257                 return -ENOMEM;
 258         }
 259
 260         return 0;
 261 }
 262 EXPORT_SYMBOL(transport_alloc_session_tags);
 263
 264 struct se_session *transport_init_session_tags(unsigned int tag_num,
 265                                                unsigned int tag_size)
 266 {
 267         struct se_session *se_sess;
 268         int rc;
 269
 270         se_sess = transport_init_session();
 271         if (IS_ERR(se_sess))
 272                 return se_sess;
 273
 274         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 275         if (rc < 0) {
 276                 transport_free_session(se_sess);
 277                 return ERR_PTR(-ENOMEM);
 278         }
 279
 280         return se_sess;
 281 }
 282 EXPORT_SYMBOL(transport_init_session_tags);
 283
 284 /*
 285  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 286  */
 287 void __transport_register_session(
 288         struct se_portal_group *se_tpg,
 289         struct se_node_acl *se_nacl,
 290         struct se_session *se_sess,
 291         void *fabric_sess_ptr)
 292 {
 293         unsigned char buf[PR_REG_ISID_LEN];
 294
 295         se_sess->se_tpg = se_tpg;
 296         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 297         /*
 298          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 299          *
 300          * Only set for struct se_session's that will actually be moving I/O.
 301          * eg: *NOT* discovery sessions.
 302          */
 303         if (se_nacl) {
 304                 /*
 305                  * If the fabric module supports an ISID based TransportID,
 306                  * save this value in binary from the fabric I_T Nexus now.
 307                  */
 308                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 309                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 310                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 311                                         &buf[0], PR_REG_ISID_LEN);
 312                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 313                 }
 314                 kref_get(&se_nacl->acl_kref);
 315
 316                 spin_lock_irq(&se_nacl->nacl_sess_lock);
 317                 /*
 318                  * The se_nacl->nacl_sess pointer will be set to the
 319                  * last active I_T Nexus for each struct se_node_acl.
 320                  */
 321                 se_nacl->nacl_sess = se_sess;
 322
 323                 list_add_tail(&se_sess->sess_acl_list,
 324                               &se_nacl->acl_sess_list);
 325                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
 326         }
 327         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 328
 329         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 330                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 331 }
 332 EXPORT_SYMBOL(__transport_register_session);
 333
 334 void transport_register_session(
 335         struct se_portal_group *se_tpg,
 336         struct se_node_acl *se_nacl,
 337         struct se_session *se_sess,
 338         void *fabric_sess_ptr)
 339 {
 340         unsigned long flags;
 341
 342         spin_lock_irqsave(&se_tpg->session_lock, flags);
 343         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 344         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 345 }
 346 EXPORT_SYMBOL(transport_register_session);
 347
 348 static void target_release_session(struct kref *kref)
 349 {
 350         struct se_session *se_sess = container_of(kref,
 351                         struct se_session, sess_kref);
 352         struct se_portal_group *se_tpg = se_sess->se_tpg;
 353
 354         se_tpg->se_tpg_tfo->close_session(se_sess);
 355 }
 356
 357 void target_get_session(struct se_session *se_sess)
 358 {
 359         kref_get(&se_sess->sess_kref);
 360 }
 361 EXPORT_SYMBOL(target_get_session);
 362
 363 void target_put_session(struct se_session *se_sess)
 364 {
 365         struct se_portal_group *tpg = se_sess->se_tpg;
 366
 367         if (tpg->se_tpg_tfo->put_session != NULL) {
 368                 tpg->se_tpg_tfo->put_session(se_sess);
 369                 return;
 370         }
 371         kref_put(&se_sess->sess_kref, target_release_session);
 372 }
 373 EXPORT_SYMBOL(target_put_session);
 374
 375 static void target_complete_nacl(struct kref *kref)
 376 {
 377         struct se_node_acl *nacl = container_of(kref,
 378                                 struct se_node_acl, acl_kref);
 379
 380         complete(&nacl->acl_free_comp);
 381 }
 382
 383 void target_put_nacl(struct se_node_acl *nacl)
 384 {
 385         kref_put(&nacl->acl_kref, target_complete_nacl);
 386 }
 387
 388 void transport_deregister_session_configfs(struct se_session *se_sess)
 389 {
 390         struct se_node_acl *se_nacl;
 391         unsigned long flags;
 392         /*
 393          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 394          */
 395         se_nacl = se_sess->se_node_acl;
 396         if (se_nacl) {
 397                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 398                 if (se_nacl->acl_stop == 0)
 399                         list_del(&se_sess->sess_acl_list);
 400                 /*
 401                  * If the session list is empty, then clear the pointer.
 402                  * Otherwise, set the struct se_session pointer from the tail
 403                  * element of the per struct se_node_acl active session list.
 404                  */
 405                 if (list_empty(&se_nacl->acl_sess_list))
 406                         se_nacl->nacl_sess = NULL;
 407                 else {
 408                         se_nacl->nacl_sess = container_of(
 409                                         se_nacl->acl_sess_list.prev,
 410                                         struct se_session, sess_acl_list);
 411                 }
 412                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 413         }
 414 }
 415 EXPORT_SYMBOL(transport_deregister_session_configfs);
 416
 417 void transport_free_session(struct se_session *se_sess)
 418 {
 419         if (se_sess->sess_cmd_map) {
 420                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 421                 if (is_vmalloc_addr(se_sess->sess_cmd_map))
 422                         vfree(se_sess->sess_cmd_map);
 423                 else
 424                         kfree(se_sess->sess_cmd_map);
 425         }
 426         kmem_cache_free(se_sess_cache, se_sess);
 427 }
 428 EXPORT_SYMBOL(transport_free_session);
 429
 430 void transport_deregister_session(struct se_session *se_sess)
 431 {
 432         struct se_portal_group *se_tpg = se_sess->se_tpg;
 433         struct target_core_fabric_ops *se_tfo;
 434         struct se_node_acl *se_nacl;
 435         unsigned long flags;
 436         bool comp_nacl = true;
 437
 438         if (!se_tpg) {
 439                 transport_free_session(se_sess);
 440                 return;
 441         }
 442         se_tfo = se_tpg->se_tpg_tfo;
 443
 444         spin_lock_irqsave(&se_tpg->session_lock, flags);
 445         list_del(&se_sess->sess_list);
 446         se_sess->se_tpg = NULL;
 447         se_sess->fabric_sess_ptr = NULL;
 448         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 449
 450         /*
 451          * Determine if we need to do extra work for this initiator node's
 452          * struct se_node_acl if it had been previously dynamically generated.
 453          */
 454         se_nacl = se_sess->se_node_acl;
 455
 456         spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
 457         if (se_nacl && se_nacl->dynamic_node_acl) {
 458                 if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 459                         list_del(&se_nacl->acl_list);
 460                         se_tpg->num_node_acls--;
 461                         spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
 462                         core_tpg_wait_for_nacl_pr_ref(se_nacl);
 463                         core_free_device_list_for_node(se_nacl, se_tpg);
 464                         se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
 465
 466                         comp_nacl = false;
 467                         spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
 468                 }
 469         }
 470         spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
 471
 472         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 473                 se_tpg->se_tpg_tfo->get_fabric_name());
 474         /*
 475          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 476          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 477          * removal context.
 478          */
 479         if (se_nacl && comp_nacl == true)
 480                 target_put_nacl(se_nacl);
 481
 482         transport_free_session(se_sess);
 483 }
 484 EXPORT_SYMBOL(transport_deregister_session);
 485
 486 /*
 487  * Called with cmd->t_state_lock held.
 488  */
 489 static void target_remove_from_state_list(struct se_cmd *cmd)
 490 {
 491         struct se_device *dev = cmd->se_dev;
 492         unsigned long flags;
 493
 494         if (!dev)
 495                 return;
 496
 497         if (cmd->transport_state & CMD_T_BUSY)
 498                 return;
 499
 500         spin_lock_irqsave(&dev->execute_task_lock, flags);
 501         if (cmd->state_active) {
 502                 list_del(&cmd->state_list);
 503                 cmd->state_active = false;
 504         }
 505         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 506 }
 507
 508 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 509                                     bool write_pending)
 510 {
 511         unsigned long flags;
 512
 513         spin_lock_irqsave(&cmd->t_state_lock, flags);
 514         if (write_pending)
 515                 cmd->t_state = TRANSPORT_WRITE_PENDING;
 516
 517         if (remove_from_lists) {
 518                 target_remove_from_state_list(cmd);
 519
 520                 /*
 521                  * Clear struct se_cmd->se_lun before the handoff to FE.
 522                  */
 523                 cmd->se_lun = NULL;
 524         }
 525
 526         /*
 527          * Determine if frontend context caller is requesting the stopping of
 528          * this command for frontend exceptions.
 529          */
 530         if (cmd->transport_state & CMD_T_STOP) {
 531                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
 532                         __func__, __LINE__,
 533                         cmd->se_tfo->get_task_tag(cmd));
 534
 535                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 536
 537                 complete(&cmd->t_transport_stop_comp);
 538                 return 1;
 539         }
 540
 541         cmd->transport_state &= ~CMD_T_ACTIVE;
 542         if (remove_from_lists) {
 543                 /*
 544                  * Some fabric modules like tcm_loop can release
 545                  * their internally allocated I/O reference now and
 546                  * struct se_cmd now.
 547                  *
 548                  * Fabric modules are expected to return '1' here if the
 549                  * se_cmd being passed is released at this point,
 550                  * or zero if not being released.
 551                  */
 552                 if (cmd->se_tfo->check_stop_free != NULL) {
 553                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 554                         return cmd->se_tfo->check_stop_free(cmd);
 555                 }
 556         }
 557
 558         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 559         return 0;
 560 }
 561
 562 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 563 {
 564         return transport_cmd_check_stop(cmd, true, false);
 565 }
 566
 567 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 568 {
 569         struct se_lun *lun = cmd->se_lun;
 570
 571         if (!lun || !cmd->lun_ref_active)
 572                 return;
 573
 574         percpu_ref_put(&lun->lun_ref);
 575 }
 576
 577 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 578 {
 579         if (transport_cmd_check_stop_to_fabric(cmd))
 580                 return;
 581         if (remove)
 582                 transport_put_cmd(cmd);
 583 }
 584
 585 static void target_complete_failure_work(struct work_struct *work)
 586 {
 587         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 588
 589         transport_generic_request_failure(cmd,
 590                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 591 }
 592
 593 /*
 594  * Used when asking transport to copy Sense Data from the underlying
 595  * Linux/SCSI struct scsi_cmnd
 596  */
 597 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 598 {
 599         struct se_device *dev = cmd->se_dev;
 600
 601         WARN_ON(!cmd->se_lun);
 602
 603         if (!dev)
 604                 return NULL;
 605
 606         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 607                 return NULL;
 608
 609         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 610
 611         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 612                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 613         return cmd->sense_buffer;
 614 }
 615
 616 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 617 {
 618         struct se_device *dev = cmd->se_dev;
 619         int success = scsi_status == GOOD;
 620         unsigned long flags;
 621
 622         cmd->scsi_status = scsi_status;
 623
 624
 625         spin_lock_irqsave(&cmd->t_state_lock, flags);
 626         cmd->transport_state &= ~CMD_T_BUSY;
 627
 628         if (dev && dev->transport->transport_complete) {
 629                 dev->transport->transport_complete(cmd,
 630                                 cmd->t_data_sg,
 631                                 transport_get_sense_buffer(cmd));
 632                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 633                         success = 1;
 634         }
 635
 636         /*
 637          * See if we are waiting to complete for an exception condition.
 638          */
 639         if (cmd->transport_state & CMD_T_REQUEST_STOP) {
 640                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 641                 complete(&cmd->task_stop_comp);
 642                 return;
 643         }
 644
 645         if (!success)
 646                 cmd->transport_state |= CMD_T_FAILED;
 647
 648         /*
 649          * Check for case where an explicit ABORT_TASK has been received
 650          * and transport_wait_for_tasks() will be waiting for completion..
 651          */
 652         if (cmd->transport_state & CMD_T_ABORTED &&
 653             cmd->transport_state & CMD_T_STOP) {
 654                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 655                 complete(&cmd->t_transport_stop_comp);
 656                 return;
 657         } else if (cmd->transport_state & CMD_T_FAILED) {
 658                 INIT_WORK(&cmd->work, target_complete_failure_work);
 659         } else {
 660                 INIT_WORK(&cmd->work, target_complete_ok_work);
 661         }
 662
 663         cmd->t_state = TRANSPORT_COMPLETE;
 664         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 665         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 666
 667         queue_work(target_completion_wq, &cmd->work);
 668 }
 669 EXPORT_SYMBOL(target_complete_cmd);
 670
 671 static void target_add_to_state_list(struct se_cmd *cmd)
 672 {
 673         struct se_device *dev = cmd->se_dev;
 674         unsigned long flags;
 675
 676         spin_lock_irqsave(&dev->execute_task_lock, flags);
 677         if (!cmd->state_active) {
 678                 list_add_tail(&cmd->state_list, &dev->state_list);
 679                 cmd->state_active = true;
 680         }
 681         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 682 }
 683
 684 /*
 685  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 686  */
 687 static void transport_write_pending_qf(struct se_cmd *cmd);
 688 static void transport_complete_qf(struct se_cmd *cmd);
 689
 690 void target_qf_do_work(struct work_struct *work)
 691 {
 692         struct se_device *dev = container_of(work, struct se_device,
 693                                         qf_work_queue);
 694         LIST_HEAD(qf_cmd_list);
 695         struct se_cmd *cmd, *cmd_tmp;
 696
 697         spin_lock_irq(&dev->qf_cmd_lock);
 698         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 699         spin_unlock_irq(&dev->qf_cmd_lock);
 700
 701         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 702                 list_del(&cmd->se_qf_node);
 703                 atomic_dec(&dev->dev_qf_count);
 704                 smp_mb__after_atomic_dec();
 705
 706                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 707                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 708                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 709                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 710                         : "UNKNOWN");
 711
 712                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 713                         transport_write_pending_qf(cmd);
 714                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 715                         transport_complete_qf(cmd);
 716         }
 717 }
 718
 719 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 720 {
 721         switch (cmd->data_direction) {
 722         case DMA_NONE:
 723                 return "NONE";
 724         case DMA_FROM_DEVICE:
 725                 return "READ";
 726         case DMA_TO_DEVICE:
 727                 return "WRITE";
 728         case DMA_BIDIRECTIONAL:
 729                 return "BIDI";
 730         default:
 731                 break;
 732         }
 733
 734         return "UNKNOWN";
 735 }
 736
 737 void transport_dump_dev_state(
 738         struct se_device *dev,
 739         char *b,
 740         int *bl)
 741 {
 742         *bl += sprintf(b + *bl, "Status: ");
 743         if (dev->export_count)
 744                 *bl += sprintf(b + *bl, "ACTIVATED");
 745         else
 746                 *bl += sprintf(b + *bl, "DEACTIVATED");
 747
 748         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 749         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 750                 dev->dev_attrib.block_size,
 751                 dev->dev_attrib.hw_max_sectors);
 752         *bl += sprintf(b + *bl, "        ");
 753 }
 754
 755 void transport_dump_vpd_proto_id(
 756         struct t10_vpd *vpd,
 757         unsigned char *p_buf,
 758         int p_buf_len)
 759 {
 760         unsigned char buf[VPD_TMP_BUF_SIZE];
 761         int len;
 762
 763         memset(buf, 0, VPD_TMP_BUF_SIZE);
 764         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 765
 766         switch (vpd->protocol_identifier) {
 767         case 0x00:
 768                 sprintf(buf+len, "Fibre Channel\n");
 769                 break;
 770         case 0x10:
 771                 sprintf(buf+len, "Parallel SCSI\n");
 772                 break;
 773         case 0x20:
 774                 sprintf(buf+len, "SSA\n");
 775                 break;
 776         case 0x30:
 777                 sprintf(buf+len, "IEEE 1394\n");
 778                 break;
 779         case 0x40:
 780                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 781                                 " Protocol\n");
 782                 break;
 783         case 0x50:
 784                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 785                 break;
 786         case 0x60:
 787                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 788                 break;
 789         case 0x70:
 790                 sprintf(buf+len, "Automation/Drive Interface Transport"
 791                                 " Protocol\n");
 792                 break;
 793         case 0x80:
 794                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 795                 break;
 796         default:
 797                 sprintf(buf+len, "Unknown 0x%02x\n",
 798                                 vpd->protocol_identifier);
 799                 break;
 800         }
 801
 802         if (p_buf)
 803                 strncpy(p_buf, buf, p_buf_len);
 804         else
 805                 pr_debug("%s", buf);
 806 }
 807
 808 void
 809 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 810 {
 811         /*
 812          * Check if the Protocol Identifier Valid (PIV) bit is set..
 813          *
 814          * from spc3r23.pdf section 7.5.1
 815          */
 816          if (page_83[1] & 0x80) {
 817                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 818                 vpd->protocol_identifier_set = 1;
 819                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 820         }
 821 }
 822 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 823
 824 int transport_dump_vpd_assoc(
 825         struct t10_vpd *vpd,
 826         unsigned char *p_buf,
 827         int p_buf_len)
 828 {
 829         unsigned char buf[VPD_TMP_BUF_SIZE];
 830         int ret = 0;
 831         int len;
 832
 833         memset(buf, 0, VPD_TMP_BUF_SIZE);
 834         len = sprintf(buf, "T10 VPD Identifier Association: ");
 835
 836         switch (vpd->association) {
 837         case 0x00:
 838                 sprintf(buf+len, "addressed logical unit\n");
 839                 break;
 840         case 0x10:
 841                 sprintf(buf+len, "target port\n");
 842                 break;
 843         case 0x20:
 844                 sprintf(buf+len, "SCSI target device\n");
 845                 break;
 846         default:
 847                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 848                 ret = -EINVAL;
 849                 break;
 850         }
 851
 852         if (p_buf)
 853                 strncpy(p_buf, buf, p_buf_len);
 854         else
 855                 pr_debug("%s", buf);
 856
 857         return ret;
 858 }
 859
 860 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 861 {
 862         /*
 863          * The VPD identification association..
 864          *
 865          * from spc3r23.pdf Section 7.6.3.1 Table 297
 866          */
 867         vpd->association = (page_83[1] & 0x30);
 868         return transport_dump_vpd_assoc(vpd, NULL, 0);
 869 }
 870 EXPORT_SYMBOL(transport_set_vpd_assoc);
 871
 872 int transport_dump_vpd_ident_type(
 873         struct t10_vpd *vpd,
 874         unsigned char *p_buf,
 875         int p_buf_len)
 876 {
 877         unsigned char buf[VPD_TMP_BUF_SIZE];
 878         int ret = 0;
 879         int len;
 880
 881         memset(buf, 0, VPD_TMP_BUF_SIZE);
 882         len = sprintf(buf, "T10 VPD Identifier Type: ");
 883
 884         switch (vpd->device_identifier_type) {
 885         case 0x00:
 886                 sprintf(buf+len, "Vendor specific\n");
 887                 break;
 888         case 0x01:
 889                 sprintf(buf+len, "T10 Vendor ID based\n");
 890                 break;
 891         case 0x02:
 892                 sprintf(buf+len, "EUI-64 based\n");
 893                 break;
 894         case 0x03:
 895                 sprintf(buf+len, "NAA\n");
 896                 break;
 897         case 0x04:
 898                 sprintf(buf+len, "Relative target port identifier\n");
 899                 break;
 900         case 0x08:
 901                 sprintf(buf+len, "SCSI name string\n");
 902                 break;
 903         default:
 904                 sprintf(buf+len, "Unsupported: 0x%02x\n",
 905                                 vpd->device_identifier_type);
 906                 ret = -EINVAL;
 907                 break;
 908         }
 909
 910         if (p_buf) {
 911                 if (p_buf_len < strlen(buf)+1)
 912                         return -EINVAL;
 913                 strncpy(p_buf, buf, p_buf_len);
 914         } else {
 915                 pr_debug("%s", buf);
 916         }
 917
 918         return ret;
 919 }
 920
 921 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
 922 {
 923         /*
 924          * The VPD identifier type..
 925          *
 926          * from spc3r23.pdf Section 7.6.3.1 Table 298
 927          */
 928         vpd->device_identifier_type = (page_83[1] & 0x0f);
 929         return transport_dump_vpd_ident_type(vpd, NULL, 0);
 930 }
 931 EXPORT_SYMBOL(transport_set_vpd_ident_type);
 932
 933 int transport_dump_vpd_ident(
 934         struct t10_vpd *vpd,
 935         unsigned char *p_buf,
 936         int p_buf_len)
 937 {
 938         unsigned char buf[VPD_TMP_BUF_SIZE];
 939         int ret = 0;
 940
 941         memset(buf, 0, VPD_TMP_BUF_SIZE);
 942
 943         switch (vpd->device_identifier_code_set) {
 944         case 0x01: /* Binary */
 945                 snprintf(buf, sizeof(buf),
 946                         "T10 VPD Binary Device Identifier: %s\n",
 947                         &vpd->device_identifier[0]);
 948                 break;
 949         case 0x02: /* ASCII */
 950                 snprintf(buf, sizeof(buf),
 951                         "T10 VPD ASCII Device Identifier: %s\n",
 952                         &vpd->device_identifier[0]);
 953                 break;
 954         case 0x03: /* UTF-8 */
 955                 snprintf(buf, sizeof(buf),
 956                         "T10 VPD UTF-8 Device Identifier: %s\n",
 957                         &vpd->device_identifier[0]);
 958                 break;
 959         default:
 960                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
 961                         " 0x%02x", vpd->device_identifier_code_set);
 962                 ret = -EINVAL;
 963                 break;
 964         }
 965
 966         if (p_buf)
 967                 strncpy(p_buf, buf, p_buf_len);
 968         else
 969                 pr_debug("%s", buf);
 970
 971         return ret;
 972 }
 973
 974 int
 975 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
 976 {
 977         static const char hex_str[] = "0123456789abcdef";
 978         int j = 0, i = 4; /* offset to start of the identifier */
 979
 980         /*
 981          * The VPD Code Set (encoding)
 982          *
 983          * from spc3r23.pdf Section 7.6.3.1 Table 296
 984          */
 985         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
 986         switch (vpd->device_identifier_code_set) {
 987         case 0x01: /* Binary */
 988                 vpd->device_identifier[j++] =
 989                                 hex_str[vpd->device_identifier_type];
 990                 while (i < (4 + page_83[3])) {
 991                         vpd->device_identifier[j++] =
 992                                 hex_str[(page_83[i] & 0xf0) >> 4];
 993                         vpd->device_identifier[j++] =
 994                                 hex_str[page_83[i] & 0x0f];
 995                         i++;
 996                 }
 997                 break;
 998         case 0x02: /* ASCII */
 999         case 0x03: /* UTF-8 */
1000                 while (i < (4 + page_83[3]))
1001                         vpd->device_identifier[j++] = page_83[i++];
1002                 break;
1003         default:
1004                 break;
1005         }
1006
1007         return transport_dump_vpd_ident(vpd, NULL, 0);
1008 }
1009 EXPORT_SYMBOL(transport_set_vpd_ident);
1010
1011 sense_reason_t
1012 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1013 {
1014         struct se_device *dev = cmd->se_dev;
1015
1016         if (cmd->unknown_data_length) {
1017                 cmd->data_length = size;
1018         } else if (size != cmd->data_length) {
1019                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1020                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1021                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1022                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1023
1024                 if (cmd->data_direction == DMA_TO_DEVICE) {
1025                         pr_err("Rejecting underflow/overflow"
1026                                         " WRITE data\n");
1027                         return TCM_INVALID_CDB_FIELD;
1028                 }
1029                 /*
1030                  * Reject READ_* or WRITE_* with overflow/underflow for
1031                  * type SCF_SCSI_DATA_CDB.
1032                  */
1033                 if (dev->dev_attrib.block_size != 512)  {
1034                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1035                                 " CDB on non 512-byte sector setup subsystem"
1036                                 " plugin: %s\n", dev->transport->name);
1037                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1038                         return TCM_INVALID_CDB_FIELD;
1039                 }
1040                 /*
1041                  * For the overflow case keep the existing fabric provided
1042                  * ->data_length.  Otherwise for the underflow case, reset
1043                  * ->data_length to the smaller SCSI expected data transfer
1044                  * length.
1045                  */
1046                 if (size > cmd->data_length) {
1047                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1048                         cmd->residual_count = (size - cmd->data_length);
1049                 } else {
1050                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1051                         cmd->residual_count = (cmd->data_length - size);
1052                         cmd->data_length = size;
1053                 }
1054         }
1055
1056         return 0;
1057
1058 }
1059
1060 /*
1061  * Used by fabric modules containing a local struct se_cmd within their
1062  * fabric dependent per I/O descriptor.
1063  */
1064 void transport_init_se_cmd(
1065         struct se_cmd *cmd,
1066         struct target_core_fabric_ops *tfo,
1067         struct se_session *se_sess,
1068         u32 data_length,
1069         int data_direction,
1070         int task_attr,
1071         unsigned char *sense_buffer)
1072 {
1073         INIT_LIST_HEAD(&cmd->se_delayed_node);
1074         INIT_LIST_HEAD(&cmd->se_qf_node);
1075         INIT_LIST_HEAD(&cmd->se_cmd_list);
1076         INIT_LIST_HEAD(&cmd->state_list);
1077         init_completion(&cmd->t_transport_stop_comp);
1078         init_completion(&cmd->cmd_wait_comp);
1079         init_completion(&cmd->task_stop_comp);
1080         spin_lock_init(&cmd->t_state_lock);
1081         cmd->transport_state = CMD_T_DEV_ACTIVE;
1082
1083         cmd->se_tfo = tfo;
1084         cmd->se_sess = se_sess;
1085         cmd->data_length = data_length;
1086         cmd->data_direction = data_direction;
1087         cmd->sam_task_attr = task_attr;
1088         cmd->sense_buffer = sense_buffer;
1089
1090         cmd->state_active = false;
1091 }
1092 EXPORT_SYMBOL(transport_init_se_cmd);
1093
1094 static sense_reason_t
1095 transport_check_alloc_task_attr(struct se_cmd *cmd)
1096 {
1097         struct se_device *dev = cmd->se_dev;
1098
1099         /*
1100          * Check if SAM Task Attribute emulation is enabled for this
1101          * struct se_device storage object
1102          */
1103         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1104                 return 0;
1105
1106         if (cmd->sam_task_attr == MSG_ACA_TAG) {
1107                 pr_debug("SAM Task Attribute ACA"
1108                         " emulation is not supported\n");
1109                 return TCM_INVALID_CDB_FIELD;
1110         }
1111         /*
1112          * Used to determine when ORDERED commands should go from
1113          * Dormant to Active status.
1114          */
1115         cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1116         smp_mb__after_atomic_inc();
1117         pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1118                         cmd->se_ordered_id, cmd->sam_task_attr,
1119                         dev->transport->name);
1120         return 0;
1121 }
1122
1123 sense_reason_t
1124 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1125 {
1126         struct se_device *dev = cmd->se_dev;
1127         sense_reason_t ret;
1128
1129         /*
1130          * Ensure that the received CDB is less than the max (252 + 8) bytes
1131          * for VARIABLE_LENGTH_CMD
1132          */
1133         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1134                 pr_err("Received SCSI CDB with command_size: %d that"
1135                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1136                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1137                 return TCM_INVALID_CDB_FIELD;
1138         }
1139         /*
1140          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1141          * allocate the additional extended CDB buffer now..  Otherwise
1142          * setup the pointer from __t_task_cdb to t_task_cdb.
1143          */
1144         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1145                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1146                                                 GFP_KERNEL);
1147                 if (!cmd->t_task_cdb) {
1148                         pr_err("Unable to allocate cmd->t_task_cdb"
1149                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1150                                 scsi_command_size(cdb),
1151                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1152                         return TCM_OUT_OF_RESOURCES;
1153                 }
1154         } else
1155                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1156         /*
1157          * Copy the original CDB into cmd->
1158          */
1159         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1160
1161         trace_target_sequencer_start(cmd);
1162
1163         /*
1164          * Check for an existing UNIT ATTENTION condition
1165          */
1166         ret = target_scsi3_ua_check(cmd);
1167         if (ret)
1168                 return ret;
1169
1170         ret = target_alua_state_check(cmd);
1171         if (ret)
1172                 return ret;
1173
1174         ret = target_check_reservation(cmd);
1175         if (ret) {
1176                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1177                 return ret;
1178         }
1179
1180         ret = dev->transport->parse_cdb(cmd);
1181         if (ret)
1182                 return ret;
1183
1184         ret = transport_check_alloc_task_attr(cmd);
1185         if (ret)
1186                 return ret;
1187
1188         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1189
1190         spin_lock(&cmd->se_lun->lun_sep_lock);
1191         if (cmd->se_lun->lun_sep)
1192                 cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1193         spin_unlock(&cmd->se_lun->lun_sep_lock);
1194         return 0;
1195 }
1196 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1197
1198 /*
1199  * Used by fabric module frontends to queue tasks directly.
1200  * Many only be used from process context only
1201  */
1202 int transport_handle_cdb_direct(
1203         struct se_cmd *cmd)
1204 {
1205         sense_reason_t ret;
1206
1207         if (!cmd->se_lun) {
1208                 dump_stack();
1209                 pr_err("cmd->se_lun is NULL\n");
1210                 return -EINVAL;
1211         }
1212         if (in_interrupt()) {
1213                 dump_stack();
1214                 pr_err("transport_generic_handle_cdb cannot be called"
1215                                 " from interrupt context\n");
1216                 return -EINVAL;
1217         }
1218         /*
1219          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1220          * outstanding descriptors are handled correctly during shutdown via
1221          * transport_wait_for_tasks()
1222          *
1223          * Also, we don't take cmd->t_state_lock here as we only expect
1224          * this to be called for initial descriptor submission.
1225          */
1226         cmd->t_state = TRANSPORT_NEW_CMD;
1227         cmd->transport_state |= CMD_T_ACTIVE;
1228
1229         /*
1230          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1231          * so follow TRANSPORT_NEW_CMD processing thread context usage
1232          * and call transport_generic_request_failure() if necessary..
1233          */
1234         ret = transport_generic_new_cmd(cmd);
1235         if (ret)
1236                 transport_generic_request_failure(cmd, ret);
1237         return 0;
1238 }
1239 EXPORT_SYMBOL(transport_handle_cdb_direct);
1240
1241 sense_reason_t
1242 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1243                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1244 {
1245         if (!sgl || !sgl_count)
1246                 return 0;
1247
1248         /*
1249          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1250          * scatterlists already have been set to follow what the fabric
1251          * passes for the original expected data transfer length.
1252          */
1253         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1254                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1255                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1256                 return TCM_INVALID_CDB_FIELD;
1257         }
1258
1259         cmd->t_data_sg = sgl;
1260         cmd->t_data_nents = sgl_count;
1261
1262         if (sgl_bidi && sgl_bidi_count) {
1263                 cmd->t_bidi_data_sg = sgl_bidi;
1264                 cmd->t_bidi_data_nents = sgl_bidi_count;
1265         }
1266         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1267         return 0;
1268 }
1269
1270 /*
1271  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1272  *                       se_cmd + use pre-allocated SGL memory.
1273  *
1274  * @se_cmd: command descriptor to submit
1275  * @se_sess: associated se_sess for endpoint
1276  * @cdb: pointer to SCSI CDB
1277  * @sense: pointer to SCSI sense buffer
1278  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1279  * @data_length: fabric expected data transfer length
1280  * @task_addr: SAM task attribute
1281  * @data_dir: DMA data direction
1282  * @flags: flags for command submission from target_sc_flags_tables
1283  * @sgl: struct scatterlist memory for unidirectional mapping
1284  * @sgl_count: scatterlist count for unidirectional mapping
1285  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1286  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1287  *
1288  * Returns non zero to signal active I/O shutdown failure.  All other
1289  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1290  * but still return zero here.
1291  *
1292  * This may only be called from process context, and also currently
1293  * assumes internal allocation of fabric payload buffer by target-core.
1294  */
1295 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1296                 unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1297                 u32 data_length, int task_attr, int data_dir, int flags,
1298                 struct scatterlist *sgl, u32 sgl_count,
1299                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1300 {
1301         struct se_portal_group *se_tpg;
1302         sense_reason_t rc;
1303         int ret;
1304
1305         se_tpg = se_sess->se_tpg;
1306         BUG_ON(!se_tpg);
1307         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1308         BUG_ON(in_interrupt());
1309         /*
1310          * Initialize se_cmd for target operation.  From this point
1311          * exceptions are handled by sending exception status via
1312          * target_core_fabric_ops->queue_status() callback
1313          */
1314         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1315                                 data_length, data_dir, task_attr, sense);
1316         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1317                 se_cmd->unknown_data_length = 1;
1318         /*
1319          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1320          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1321          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1322          * kref_put() to happen during fabric packet acknowledgement.
1323          */
1324         ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1325         if (ret)
1326                 return ret;
1327         /*
1328          * Signal bidirectional data payloads to target-core
1329          */
1330         if (flags & TARGET_SCF_BIDI_OP)
1331                 se_cmd->se_cmd_flags |= SCF_BIDI;
1332         /*
1333          * Locate se_lun pointer and attach it to struct se_cmd
1334          */
1335         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1336         if (rc) {
1337                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1338                 target_put_sess_cmd(se_sess, se_cmd);
1339                 return 0;
1340         }
1341
1342         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1343         if (rc != 0) {
1344                 transport_generic_request_failure(se_cmd, rc);
1345                 return 0;
1346         }
1347         /*
1348          * When a non zero sgl_count has been passed perform SGL passthrough
1349          * mapping for pre-allocated fabric memory instead of having target
1350          * core perform an internal SGL allocation..
1351          */
1352         if (sgl_count != 0) {
1353                 BUG_ON(!sgl);
1354
1355                 /*
1356                  * A work-around for tcm_loop as some userspace code via
1357                  * scsi-generic do not memset their associated read buffers,
1358                  * so go ahead and do that here for type non-data CDBs.  Also
1359                  * note that this is currently guaranteed to be a single SGL
1360                  * for this case by target core in target_setup_cmd_from_cdb()
1361                  * -> transport_generic_cmd_sequencer().
1362                  */
1363                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1364                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1365                         unsigned char *buf = NULL;
1366
1367                         if (sgl)
1368                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1369
1370                         if (buf) {
1371                                 memset(buf, 0, sgl->length);
1372                                 kunmap(sg_page(sgl));
1373                         }
1374                 }
1375
1376                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1377                                 sgl_bidi, sgl_bidi_count);
1378                 if (rc != 0) {
1379                         transport_generic_request_failure(se_cmd, rc);
1380                         return 0;
1381                 }
1382         }
1383         /*
1384          * Check if we need to delay processing because of ALUA
1385          * Active/NonOptimized primary access state..
1386          */
1387         core_alua_check_nonop_delay(se_cmd);
1388
1389         transport_handle_cdb_direct(se_cmd);
1390         return 0;
1391 }
1392 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1393
1394 /*
1395  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1396  *
1397  * @se_cmd: command descriptor to submit
1398  * @se_sess: associated se_sess for endpoint
1399  * @cdb: pointer to SCSI CDB
1400  * @sense: pointer to SCSI sense buffer
1401  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1402  * @data_length: fabric expected data transfer length
1403  * @task_addr: SAM task attribute
1404  * @data_dir: DMA data direction
1405  * @flags: flags for command submission from target_sc_flags_tables
1406  *
1407  * Returns non zero to signal active I/O shutdown failure.  All other
1408  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1409  * but still return zero here.
1410  *
1411  * This may only be called from process context, and also currently
1412  * assumes internal allocation of fabric payload buffer by target-core.
1413  *
1414  * It also assumes interal target core SGL memory allocation.
1415  */
1416 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1417                 unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1418                 u32 data_length, int task_attr, int data_dir, int flags)
1419 {
1420         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1421                         unpacked_lun, data_length, task_attr, data_dir,
1422                         flags, NULL, 0, NULL, 0);
1423 }
1424 EXPORT_SYMBOL(target_submit_cmd);
1425
1426 static void target_complete_tmr_failure(struct work_struct *work)
1427 {
1428         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1429
1430         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1431         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1432
1433         transport_cmd_check_stop_to_fabric(se_cmd);
1434 }
1435
1436 /**
1437  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1438  *                     for TMR CDBs
1439  *
1440  * @se_cmd: command descriptor to submit
1441  * @se_sess: associated se_sess for endpoint
1442  * @sense: pointer to SCSI sense buffer
1443  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1444  * @fabric_context: fabric context for TMR req
1445  * @tm_type: Type of TM request
1446  * @gfp: gfp type for caller
1447  * @tag: referenced task tag for TMR_ABORT_TASK
1448  * @flags: submit cmd flags
1449  *
1450  * Callable from all contexts.
1451  **/
1452
1453 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1454                 unsigned char *sense, u32 unpacked_lun,
1455                 void *fabric_tmr_ptr, unsigned char tm_type,
1456                 gfp_t gfp, unsigned int tag, int flags)
1457 {
1458         struct se_portal_group *se_tpg;
1459         int ret;
1460
1461         se_tpg = se_sess->se_tpg;
1462         BUG_ON(!se_tpg);
1463
1464         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1465                               0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1466         /*
1467          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1468          * allocation failure.
1469          */
1470         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1471         if (ret < 0)
1472                 return -ENOMEM;
1473
1474         if (tm_type == TMR_ABORT_TASK)
1475                 se_cmd->se_tmr_req->ref_task_tag = tag;
1476
1477         /* See target_submit_cmd for commentary */
1478         ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1479         if (ret) {
1480                 core_tmr_release_req(se_cmd->se_tmr_req);
1481                 return ret;
1482         }
1483
1484         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1485         if (ret) {
1486                 /*
1487                  * For callback during failure handling, push this work off
1488                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1489                  */
1490                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1491                 schedule_work(&se_cmd->work);
1492                 return 0;
1493         }
1494         transport_generic_handle_tmr(se_cmd);
1495         return 0;
1496 }
1497 EXPORT_SYMBOL(target_submit_tmr);
1498
1499 /*
1500  * If the cmd is active, request it to be stopped and sleep until it
1501  * has completed.
1502  */
1503 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1504 {
1505         bool was_active = false;
1506
1507         if (cmd->transport_state & CMD_T_BUSY) {
1508                 cmd->transport_state |= CMD_T_REQUEST_STOP;
1509                 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1510
1511                 pr_debug("cmd %p waiting to complete\n", cmd);
1512                 wait_for_completion(&cmd->task_stop_comp);
1513                 pr_debug("cmd %p stopped successfully\n", cmd);
1514
1515                 spin_lock_irqsave(&cmd->t_state_lock, *flags);
1516                 cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1517                 cmd->transport_state &= ~CMD_T_BUSY;
1518                 was_active = true;
1519         }
1520
1521         return was_active;
1522 }
1523
1524 /*
1525  * Handle SAM-esque emulation for generic transport request failures.
1526  */
1527 void transport_generic_request_failure(struct se_cmd *cmd,
1528                 sense_reason_t sense_reason)
1529 {
1530         int ret = 0;
1531
1532         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1533                 " CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1534                 cmd->t_task_cdb[0]);
1535         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1536                 cmd->se_tfo->get_cmd_state(cmd),
1537                 cmd->t_state, sense_reason);
1538         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1539                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1540                 (cmd->transport_state & CMD_T_STOP) != 0,
1541                 (cmd->transport_state & CMD_T_SENT) != 0);
1542
1543         /*
1544          * For SAM Task Attribute emulation for failed struct se_cmd
1545          */
1546         transport_complete_task_attr(cmd);
1547         /*
1548          * Handle special case for COMPARE_AND_WRITE failure, where the
1549          * callback is expected to drop the per device ->caw_mutex.
1550          */
1551         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1552              cmd->transport_complete_callback)
1553                 cmd->transport_complete_callback(cmd);
1554
1555         switch (sense_reason) {
1556         case TCM_NON_EXISTENT_LUN:
1557         case TCM_UNSUPPORTED_SCSI_OPCODE:
1558         case TCM_INVALID_CDB_FIELD:
1559         case TCM_INVALID_PARAMETER_LIST:
1560         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1561         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1562         case TCM_UNKNOWN_MODE_PAGE:
1563         case TCM_WRITE_PROTECTED:
1564         case TCM_ADDRESS_OUT_OF_RANGE:
1565         case TCM_CHECK_CONDITION_ABORT_CMD:
1566         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1567         case TCM_CHECK_CONDITION_NOT_READY:
1568                 break;
1569         case TCM_OUT_OF_RESOURCES:
1570                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1571                 break;
1572         case TCM_RESERVATION_CONFLICT:
1573                 /*
1574                  * No SENSE Data payload for this case, set SCSI Status
1575                  * and queue the response to $FABRIC_MOD.
1576                  *
1577                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1578                  */
1579                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1580                 /*
1581                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1582                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1583                  * CONFLICT STATUS.
1584                  *
1585                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1586                  */
1587                 if (cmd->se_sess &&
1588                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1589                         core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1590                                 cmd->orig_fe_lun, 0x2C,
1591                                 ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1592
1593                 trace_target_cmd_complete(cmd);
1594                 ret = cmd->se_tfo-> queue_status(cmd);
1595                 if (ret == -EAGAIN || ret == -ENOMEM)
1596                         goto queue_full;
1597                 goto check_stop;
1598         default:
1599                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1600                         cmd->t_task_cdb[0], sense_reason);
1601                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1602                 break;
1603         }
1604
1605         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1606         if (ret == -EAGAIN || ret == -ENOMEM)
1607                 goto queue_full;
1608
1609 check_stop:
1610         transport_lun_remove_cmd(cmd);
1611         if (!transport_cmd_check_stop_to_fabric(cmd))
1612                 ;
1613         return;
1614
1615 queue_full:
1616         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1617         transport_handle_queue_full(cmd, cmd->se_dev);
1618 }
1619 EXPORT_SYMBOL(transport_generic_request_failure);
1620
1621 void __target_execute_cmd(struct se_cmd *cmd)
1622 {
1623         sense_reason_t ret;
1624
1625         if (cmd->execute_cmd) {
1626                 ret = cmd->execute_cmd(cmd);
1627                 if (ret) {
1628                         spin_lock_irq(&cmd->t_state_lock);
1629                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1630                         spin_unlock_irq(&cmd->t_state_lock);
1631
1632                         transport_generic_request_failure(cmd, ret);
1633                 }
1634         }
1635 }
1636
1637 static bool target_handle_task_attr(struct se_cmd *cmd)
1638 {
1639         struct se_device *dev = cmd->se_dev;
1640
1641         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1642                 return false;
1643
1644         /*
1645          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1646          * to allow the passed struct se_cmd list of tasks to the front of the list.
1647          */
1648         switch (cmd->sam_task_attr) {
1649         case MSG_HEAD_TAG:
1650                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1651                          "se_ordered_id: %u\n",
1652                          cmd->t_task_cdb[0], cmd->se_ordered_id);
1653                 return false;
1654         case MSG_ORDERED_TAG:
1655                 atomic_inc(&dev->dev_ordered_sync);
1656                 smp_mb__after_atomic_inc();
1657
1658                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1659                          " se_ordered_id: %u\n",
1660                          cmd->t_task_cdb[0], cmd->se_ordered_id);
1661
1662                 /*
1663                  * Execute an ORDERED command if no other older commands
1664                  * exist that need to be completed first.
1665                  */
1666                 if (!atomic_read(&dev->simple_cmds))
1667                         return false;
1668                 break;
1669         default:
1670                 /*
1671                  * For SIMPLE and UNTAGGED Task Attribute commands
1672                  */
1673                 atomic_inc(&dev->simple_cmds);
1674                 smp_mb__after_atomic_inc();
1675                 break;
1676         }
1677
1678         if (atomic_read(&dev->dev_ordered_sync) == 0)
1679                 return false;
1680
1681         spin_lock(&dev->delayed_cmd_lock);
1682         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1683         spin_unlock(&dev->delayed_cmd_lock);
1684
1685         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1686                 " delayed CMD list, se_ordered_id: %u\n",
1687                 cmd->t_task_cdb[0], cmd->sam_task_attr,
1688                 cmd->se_ordered_id);
1689         return true;
1690 }
1691
1692 void target_execute_cmd(struct se_cmd *cmd)
1693 {
1694         /*
1695          * If the received CDB has aleady been aborted stop processing it here.
1696          */
1697         if (transport_check_aborted_status(cmd, 1))
1698                 return;
1699
1700         /*
1701          * Determine if frontend context caller is requesting the stopping of
1702          * this command for frontend exceptions.
1703          */
1704         spin_lock_irq(&cmd->t_state_lock);
1705         if (cmd->transport_state & CMD_T_STOP) {
1706                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1707                         __func__, __LINE__,
1708                         cmd->se_tfo->get_task_tag(cmd));
1709
1710                 spin_unlock_irq(&cmd->t_state_lock);
1711                 complete(&cmd->t_transport_stop_comp);
1712                 return;
1713         }
1714
1715         cmd->t_state = TRANSPORT_PROCESSING;
1716         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1717         spin_unlock_irq(&cmd->t_state_lock);
1718
1719         if (target_handle_task_attr(cmd)) {
1720                 spin_lock_irq(&cmd->t_state_lock);
1721                 cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT;
1722                 spin_unlock_irq(&cmd->t_state_lock);
1723                 return;
1724         }
1725
1726         __target_execute_cmd(cmd);
1727 }
1728 EXPORT_SYMBOL(target_execute_cmd);
1729
1730 /*
1731  * Process all commands up to the last received ORDERED task attribute which
1732  * requires another blocking boundary
1733  */
1734 static void target_restart_delayed_cmds(struct se_device *dev)
1735 {
1736         for (;;) {
1737                 struct se_cmd *cmd;
1738
1739                 spin_lock(&dev->delayed_cmd_lock);
1740                 if (list_empty(&dev->delayed_cmd_list)) {
1741                         spin_unlock(&dev->delayed_cmd_lock);
1742                         break;
1743                 }
1744
1745                 cmd = list_entry(dev->delayed_cmd_list.next,
1746                                  struct se_cmd, se_delayed_node);
1747                 list_del(&cmd->se_delayed_node);
1748                 spin_unlock(&dev->delayed_cmd_lock);
1749
1750                 __target_execute_cmd(cmd);
1751
1752                 if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1753                         break;
1754         }
1755 }
1756
1757 /*
1758  * Called from I/O completion to determine which dormant/delayed
1759  * and ordered cmds need to have their tasks added to the execution queue.
1760  */
1761 static void transport_complete_task_attr(struct se_cmd *cmd)
1762 {
1763         struct se_device *dev = cmd->se_dev;
1764
1765         if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1766                 return;
1767
1768         if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1769                 atomic_dec(&dev->simple_cmds);
1770                 smp_mb__after_atomic_dec();
1771                 dev->dev_cur_ordered_id++;
1772                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1773                         " SIMPLE: %u\n", dev->dev_cur_ordered_id,
1774                         cmd->se_ordered_id);
1775         } else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1776                 dev->dev_cur_ordered_id++;
1777                 pr_debug("Incremented dev_cur_ordered_id: %u for"
1778                         " HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1779                         cmd->se_ordered_id);
1780         } else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1781                 atomic_dec(&dev->dev_ordered_sync);
1782                 smp_mb__after_atomic_dec();
1783
1784                 dev->dev_cur_ordered_id++;
1785                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1786                         " %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1787         }
1788
1789         target_restart_delayed_cmds(dev);
1790 }
1791
1792 static void transport_complete_qf(struct se_cmd *cmd)
1793 {
1794         int ret = 0;
1795
1796         transport_complete_task_attr(cmd);
1797
1798         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1799                 trace_target_cmd_complete(cmd);
1800                 ret = cmd->se_tfo->queue_status(cmd);
1801                 if (ret)
1802                         goto out;
1803         }
1804
1805         switch (cmd->data_direction) {
1806         case DMA_FROM_DEVICE:
1807                 trace_target_cmd_complete(cmd);
1808                 ret = cmd->se_tfo->queue_data_in(cmd);
1809                 break;
1810         case DMA_TO_DEVICE:
1811                 if (cmd->se_cmd_flags & SCF_BIDI) {
1812                         ret = cmd->se_tfo->queue_data_in(cmd);
1813                         if (ret < 0)
1814                                 break;
1815                 }
1816                 /* Fall through for DMA_TO_DEVICE */
1817         case DMA_NONE:
1818                 trace_target_cmd_complete(cmd);
1819                 ret = cmd->se_tfo->queue_status(cmd);
1820                 break;
1821         default:
1822                 break;
1823         }
1824
1825 out:
1826         if (ret < 0) {
1827                 transport_handle_queue_full(cmd, cmd->se_dev);
1828                 return;
1829         }
1830         transport_lun_remove_cmd(cmd);
1831         transport_cmd_check_stop_to_fabric(cmd);
1832 }
1833
1834 static void transport_handle_queue_full(
1835         struct se_cmd *cmd,
1836         struct se_device *dev)
1837 {
1838         spin_lock_irq(&dev->qf_cmd_lock);
1839         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1840         atomic_inc(&dev->dev_qf_count);
1841         smp_mb__after_atomic_inc();
1842         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1843
1844         schedule_work(&cmd->se_dev->qf_work_queue);
1845 }
1846
1847 static void target_complete_ok_work(struct work_struct *work)
1848 {
1849         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1850         int ret;
1851
1852         /*
1853          * Check if we need to move delayed/dormant tasks from cmds on the
1854          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1855          * Attribute.
1856          */
1857         transport_complete_task_attr(cmd);
1858
1859         /*
1860          * Check to schedule QUEUE_FULL work, or execute an existing
1861          * cmd->transport_qf_callback()
1862          */
1863         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1864                 schedule_work(&cmd->se_dev->qf_work_queue);
1865
1866         /*
1867          * Check if we need to send a sense buffer from
1868          * the struct se_cmd in question.
1869          */
1870         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1871                 WARN_ON(!cmd->scsi_status);
1872                 ret = transport_send_check_condition_and_sense(
1873                                         cmd, 0, 1);
1874                 if (ret == -EAGAIN || ret == -ENOMEM)
1875                         goto queue_full;
1876
1877                 transport_lun_remove_cmd(cmd);
1878                 transport_cmd_check_stop_to_fabric(cmd);
1879                 return;
1880         }
1881         /*
1882          * Check for a callback, used by amongst other things
1883          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
1884          */
1885         if (cmd->transport_complete_callback) {
1886                 sense_reason_t rc;
1887
1888                 rc = cmd->transport_complete_callback(cmd);
1889                 if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
1890                         return;
1891                 } else if (rc) {
1892                         ret = transport_send_check_condition_and_sense(cmd,
1893                                                 rc, 0);
1894                         if (ret == -EAGAIN || ret == -ENOMEM)
1895                                 goto queue_full;
1896
1897                         transport_lun_remove_cmd(cmd);
1898                         transport_cmd_check_stop_to_fabric(cmd);
1899                         return;
1900                 }
1901         }
1902
1903         switch (cmd->data_direction) {
1904         case DMA_FROM_DEVICE:
1905                 spin_lock(&cmd->se_lun->lun_sep_lock);
1906                 if (cmd->se_lun->lun_sep) {
1907                         cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1908                                         cmd->data_length;
1909                 }
1910                 spin_unlock(&cmd->se_lun->lun_sep_lock);
1911
1912                 trace_target_cmd_complete(cmd);
1913                 ret = cmd->se_tfo->queue_data_in(cmd);
1914                 if (ret == -EAGAIN || ret == -ENOMEM)
1915                         goto queue_full;
1916                 break;
1917         case DMA_TO_DEVICE:
1918                 spin_lock(&cmd->se_lun->lun_sep_lock);
1919                 if (cmd->se_lun->lun_sep) {
1920                         cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
1921                                 cmd->data_length;
1922                 }
1923                 spin_unlock(&cmd->se_lun->lun_sep_lock);
1924                 /*
1925                  * Check if we need to send READ payload for BIDI-COMMAND
1926                  */
1927                 if (cmd->se_cmd_flags & SCF_BIDI) {
1928                         spin_lock(&cmd->se_lun->lun_sep_lock);
1929                         if (cmd->se_lun->lun_sep) {
1930                                 cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1931                                         cmd->data_length;
1932                         }
1933                         spin_unlock(&cmd->se_lun->lun_sep_lock);
1934                         ret = cmd->se_tfo->queue_data_in(cmd);
1935                         if (ret == -EAGAIN || ret == -ENOMEM)
1936                                 goto queue_full;
1937                         break;
1938                 }
1939                 /* Fall through for DMA_TO_DEVICE */
1940         case DMA_NONE:
1941                 trace_target_cmd_complete(cmd);
1942                 ret = cmd->se_tfo->queue_status(cmd);
1943                 if (ret == -EAGAIN || ret == -ENOMEM)
1944                         goto queue_full;
1945                 break;
1946         default:
1947                 break;
1948         }
1949
1950         transport_lun_remove_cmd(cmd);
1951         transport_cmd_check_stop_to_fabric(cmd);
1952         return;
1953
1954 queue_full:
1955         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
1956                 " data_direction: %d\n", cmd, cmd->data_direction);
1957         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1958         transport_handle_queue_full(cmd, cmd->se_dev);
1959 }
1960
1961 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
1962 {
1963         struct scatterlist *sg;
1964         int count;
1965
1966         for_each_sg(sgl, sg, nents, count)
1967                 __free_page(sg_page(sg));
1968
1969         kfree(sgl);
1970 }
1971
1972 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
1973 {
1974         /*
1975          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
1976          * emulation, and free + reset pointers if necessary..
1977          */
1978         if (!cmd->t_data_sg_orig)
1979                 return;
1980
1981         kfree(cmd->t_data_sg);
1982         cmd->t_data_sg = cmd->t_data_sg_orig;
1983         cmd->t_data_sg_orig = NULL;
1984         cmd->t_data_nents = cmd->t_data_nents_orig;
1985         cmd->t_data_nents_orig = 0;
1986 }
1987
1988 static inline void transport_free_pages(struct se_cmd *cmd)
1989 {
1990         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
1991                 transport_reset_sgl_orig(cmd);
1992                 return;
1993         }
1994         transport_reset_sgl_orig(cmd);
1995
1996         transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
1997         cmd->t_data_sg = NULL;
1998         cmd->t_data_nents = 0;
1999
2000         transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2001         cmd->t_bidi_data_sg = NULL;
2002         cmd->t_bidi_data_nents = 0;
2003 }
2004
2005 /**
2006  * transport_release_cmd - free a command
2007  * @cmd:       command to free
2008  *
2009  * This routine unconditionally frees a command, and reference counting
2010  * or list removal must be done in the caller.
2011  */
2012 static int transport_release_cmd(struct se_cmd *cmd)
2013 {
2014         BUG_ON(!cmd->se_tfo);
2015
2016         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2017                 core_tmr_release_req(cmd->se_tmr_req);
2018         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2019                 kfree(cmd->t_task_cdb);
2020         /*
2021          * If this cmd has been setup with target_get_sess_cmd(), drop
2022          * the kref and call ->release_cmd() in kref callback.
2023          */
2024         return target_put_sess_cmd(cmd->se_sess, cmd);
2025 }
2026
2027 /**
2028  * transport_put_cmd - release a reference to a command
2029  * @cmd:       command to release
2030  *
2031  * This routine releases our reference to the command and frees it if possible.
2032  */
2033 static int transport_put_cmd(struct se_cmd *cmd)
2034 {
2035         transport_free_pages(cmd);
2036         return transport_release_cmd(cmd);
2037 }
2038
2039 void *transport_kmap_data_sg(struct se_cmd *cmd)
2040 {
2041         struct scatterlist *sg = cmd->t_data_sg;
2042         struct page **pages;
2043         int i;
2044
2045         /*
2046          * We need to take into account a possible offset here for fabrics like
2047          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2048          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2049          */
2050         if (!cmd->t_data_nents)
2051                 return NULL;
2052
2053         BUG_ON(!sg);
2054         if (cmd->t_data_nents == 1)
2055                 return kmap(sg_page(sg)) + sg->offset;
2056
2057         /* >1 page. use vmap */
2058         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2059         if (!pages)
2060                 return NULL;
2061
2062         /* convert sg[] to pages[] */
2063         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2064                 pages[i] = sg_page(sg);
2065         }
2066
2067         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2068         kfree(pages);
2069         if (!cmd->t_data_vmap)
2070                 return NULL;
2071
2072         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2073 }
2074 EXPORT_SYMBOL(transport_kmap_data_sg);
2075
2076 void transport_kunmap_data_sg(struct se_cmd *cmd)
2077 {
2078         if (!cmd->t_data_nents) {
2079                 return;
2080         } else if (cmd->t_data_nents == 1) {
2081                 kunmap(sg_page(cmd->t_data_sg));
2082                 return;
2083         }
2084
2085         vunmap(cmd->t_data_vmap);
2086         cmd->t_data_vmap = NULL;
2087 }
2088 EXPORT_SYMBOL(transport_kunmap_data_sg);
2089
2090 int
2091 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2092                  bool zero_page)
2093 {
2094         struct scatterlist *sg;
2095         struct page *page;
2096         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2097         unsigned int nent;
2098         int i = 0;
2099
2100         nent = DIV_ROUND_UP(length, PAGE_SIZE);
2101         sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2102         if (!sg)
2103                 return -ENOMEM;
2104
2105         sg_init_table(sg, nent);
2106
2107         while (length) {
2108                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2109                 page = alloc_page(GFP_KERNEL | zero_flag);
2110                 if (!page)
2111                         goto out;
2112
2113                 sg_set_page(&sg[i], page, page_len, 0);
2114                 length -= page_len;
2115                 i++;
2116         }
2117         *sgl = sg;
2118         *nents = nent;
2119         return 0;
2120
2121 out:
2122         while (i > 0) {
2123                 i--;
2124                 __free_page(sg_page(&sg[i]));
2125         }
2126         kfree(sg);
2127         return -ENOMEM;
2128 }
2129
2130 /*
2131  * Allocate any required resources to execute the command.  For writes we
2132  * might not have the payload yet, so notify the fabric via a call to
2133  * ->write_pending instead. Otherwise place it on the execution queue.
2134  */
2135 sense_reason_t
2136 transport_generic_new_cmd(struct se_cmd *cmd)
2137 {
2138         int ret = 0;
2139
2140         /*
2141          * Determine is the TCM fabric module has already allocated physical
2142          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2143          * beforehand.
2144          */
2145         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2146             cmd->data_length) {
2147                 bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2148
2149                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2150                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2151                         u32 bidi_length;
2152
2153                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2154                                 bidi_length = cmd->t_task_nolb *
2155                                               cmd->se_dev->dev_attrib.block_size;
2156                         else
2157                                 bidi_length = cmd->data_length;
2158
2159                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2160                                                &cmd->t_bidi_data_nents,
2161                                                bidi_length, zero_flag);
2162                         if (ret < 0)
2163                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2164                 }
2165
2166                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2167                                        cmd->data_length, zero_flag);
2168                 if (ret < 0)
2169                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2170         }
2171         /*
2172          * If this command is not a write we can execute it right here,
2173          * for write buffers we need to notify the fabric driver first
2174          * and let it call back once the write buffers are ready.
2175          */
2176         target_add_to_state_list(cmd);
2177         if (cmd->data_direction != DMA_TO_DEVICE) {
2178                 target_execute_cmd(cmd);
2179                 return 0;
2180         }
2181         transport_cmd_check_stop(cmd, false, true);
2182
2183         ret = cmd->se_tfo->write_pending(cmd);
2184         if (ret == -EAGAIN || ret == -ENOMEM)
2185                 goto queue_full;
2186
2187         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2188         WARN_ON(ret);
2189
2190         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2191
2192 queue_full:
2193         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2194         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2195         transport_handle_queue_full(cmd, cmd->se_dev);
2196         return 0;
2197 }
2198 EXPORT_SYMBOL(transport_generic_new_cmd);
2199
2200 static void transport_write_pending_qf(struct se_cmd *cmd)
2201 {
2202         int ret;
2203
2204         ret = cmd->se_tfo->write_pending(cmd);
2205         if (ret == -EAGAIN || ret == -ENOMEM) {
2206                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2207                          cmd);
2208                 transport_handle_queue_full(cmd, cmd->se_dev);
2209         }
2210 }
2211
2212 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2213 {
2214         unsigned long flags;
2215         int ret = 0;
2216
2217         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2218                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2219                          transport_wait_for_tasks(cmd);
2220
2221                 ret = transport_release_cmd(cmd);
2222         } else {
2223                 if (wait_for_tasks)
2224                         transport_wait_for_tasks(cmd);
2225                 /*
2226                  * Handle WRITE failure case where transport_generic_new_cmd()
2227                  * has already added se_cmd to state_list, but fabric has
2228                  * failed command before I/O submission.
2229                  */
2230                 if (cmd->state_active) {
2231                         spin_lock_irqsave(&cmd->t_state_lock, flags);
2232                         target_remove_from_state_list(cmd);
2233                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2234                 }
2235
2236                 if (cmd->se_lun)
2237                         transport_lun_remove_cmd(cmd);
2238
2239                 ret = transport_put_cmd(cmd);
2240         }
2241         return ret;
2242 }
2243 EXPORT_SYMBOL(transport_generic_free_cmd);
2244
2245 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2246  * @se_sess:    session to reference
2247  * @se_cmd:     command descriptor to add
2248  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2249  */
2250 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2251                                bool ack_kref)
2252 {
2253         unsigned long flags;
2254         int ret = 0;
2255
2256         kref_init(&se_cmd->cmd_kref);
2257         /*
2258          * Add a second kref if the fabric caller is expecting to handle
2259          * fabric acknowledgement that requires two target_put_sess_cmd()
2260          * invocations before se_cmd descriptor release.
2261          */
2262         if (ack_kref == true) {
2263                 kref_get(&se_cmd->cmd_kref);
2264                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2265         }
2266
2267         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2268         if (se_sess->sess_tearing_down) {
2269                 ret = -ESHUTDOWN;
2270                 goto out;
2271         }
2272         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2273 out:
2274         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2275         return ret;
2276 }
2277 EXPORT_SYMBOL(target_get_sess_cmd);
2278
2279 static void target_release_cmd_kref(struct kref *kref)
2280 {
2281         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2282         struct se_session *se_sess = se_cmd->se_sess;
2283
2284         if (list_empty(&se_cmd->se_cmd_list)) {
2285                 spin_unlock(&se_sess->sess_cmd_lock);
2286                 se_cmd->se_tfo->release_cmd(se_cmd);
2287                 return;
2288         }
2289         if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2290                 spin_unlock(&se_sess->sess_cmd_lock);
2291                 complete(&se_cmd->cmd_wait_comp);
2292                 return;
2293         }
2294         list_del(&se_cmd->se_cmd_list);
2295         spin_unlock(&se_sess->sess_cmd_lock);
2296
2297         se_cmd->se_tfo->release_cmd(se_cmd);
2298 }
2299
2300 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2301  * @se_sess:    session to reference
2302  * @se_cmd:     command descriptor to drop
2303  */
2304 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2305 {
2306         return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2307                         &se_sess->sess_cmd_lock);
2308 }
2309 EXPORT_SYMBOL(target_put_sess_cmd);
2310
2311 /* target_sess_cmd_list_set_waiting - Flag all commands in
2312  *         sess_cmd_list to complete cmd_wait_comp.  Set
2313  *         sess_tearing_down so no more commands are queued.
2314  * @se_sess:    session to flag
2315  */
2316 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2317 {
2318         struct se_cmd *se_cmd;
2319         unsigned long flags;
2320
2321         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2322         if (se_sess->sess_tearing_down) {
2323                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2324                 return;
2325         }
2326         se_sess->sess_tearing_down = 1;
2327         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2328
2329         list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2330                 se_cmd->cmd_wait_set = 1;
2331
2332         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2333 }
2334 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2335
2336 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2337  * @se_sess:    session to wait for active I/O
2338  */
2339 void target_wait_for_sess_cmds(struct se_session *se_sess)
2340 {
2341         struct se_cmd *se_cmd, *tmp_cmd;
2342         unsigned long flags;
2343
2344         list_for_each_entry_safe(se_cmd, tmp_cmd,
2345                                 &se_sess->sess_wait_list, se_cmd_list) {
2346                 list_del(&se_cmd->se_cmd_list);
2347
2348                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2349                         " %d\n", se_cmd, se_cmd->t_state,
2350                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2351
2352                 wait_for_completion(&se_cmd->cmd_wait_comp);
2353                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2354                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2355                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2356
2357                 se_cmd->se_tfo->release_cmd(se_cmd);
2358         }
2359
2360         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2361         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2362         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2363
2364 }
2365 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2366
2367 static int transport_clear_lun_ref_thread(void *p)
2368 {
2369         struct se_lun *lun = p;
2370
2371         percpu_ref_kill(&lun->lun_ref);
2372
2373         wait_for_completion(&lun->lun_ref_comp);
2374         complete(&lun->lun_shutdown_comp);
2375
2376         return 0;
2377 }
2378
2379 int transport_clear_lun_ref(struct se_lun *lun)
2380 {
2381         struct task_struct *kt;
2382
2383         kt = kthread_run(transport_clear_lun_ref_thread, lun,
2384                         "tcm_cl_%u", lun->unpacked_lun);
2385         if (IS_ERR(kt)) {
2386                 pr_err("Unable to start clear_lun thread\n");
2387                 return PTR_ERR(kt);
2388         }
2389         wait_for_completion(&lun->lun_shutdown_comp);
2390
2391         return 0;
2392 }
2393
2394 /**
2395  * transport_wait_for_tasks - wait for completion to occur
2396  * @cmd:        command to wait
2397  *
2398  * Called from frontend fabric context to wait for storage engine
2399  * to pause and/or release frontend generated struct se_cmd.
2400  */
2401 bool transport_wait_for_tasks(struct se_cmd *cmd)
2402 {
2403         unsigned long flags;
2404
2405         spin_lock_irqsave(&cmd->t_state_lock, flags);
2406         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2407             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2408                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2409                 return false;
2410         }
2411
2412         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2413             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2414                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2415                 return false;
2416         }
2417
2418         if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2419                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2420                 return false;
2421         }
2422
2423         cmd->transport_state |= CMD_T_STOP;
2424
2425         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2426                 " i_state: %d, t_state: %d, CMD_T_STOP\n",
2427                 cmd, cmd->se_tfo->get_task_tag(cmd),
2428                 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2429
2430         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2431
2432         wait_for_completion(&cmd->t_transport_stop_comp);
2433
2434         spin_lock_irqsave(&cmd->t_state_lock, flags);
2435         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2436
2437         pr_debug("wait_for_tasks: Stopped wait_for_completion("
2438                 "&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2439                 cmd->se_tfo->get_task_tag(cmd));
2440
2441         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2442
2443         return true;
2444 }
2445 EXPORT_SYMBOL(transport_wait_for_tasks);
2446
2447 static int transport_get_sense_codes(
2448         struct se_cmd *cmd,
2449         u8 *asc,
2450         u8 *ascq)
2451 {
2452         *asc = cmd->scsi_asc;
2453         *ascq = cmd->scsi_ascq;
2454
2455         return 0;
2456 }
2457
2458 int
2459 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2460                 sense_reason_t reason, int from_transport)
2461 {
2462         unsigned char *buffer = cmd->sense_buffer;
2463         unsigned long flags;
2464         u8 asc = 0, ascq = 0;
2465
2466         spin_lock_irqsave(&cmd->t_state_lock, flags);
2467         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2468                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2469                 return 0;
2470         }
2471         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2472         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2473
2474         if (!reason && from_transport)
2475                 goto after_reason;
2476
2477         if (!from_transport)
2478                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2479
2480         /*
2481          * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2482          * SENSE KEY values from include/scsi/scsi.h
2483          */
2484         switch (reason) {
2485         case TCM_NO_SENSE:
2486                 /* CURRENT ERROR */
2487                 buffer[0] = 0x70;
2488                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2489                 /* Not Ready */
2490                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2491                 /* NO ADDITIONAL SENSE INFORMATION */
2492                 buffer[SPC_ASC_KEY_OFFSET] = 0;
2493                 buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2494                 break;
2495         case TCM_NON_EXISTENT_LUN:
2496                 /* CURRENT ERROR */
2497                 buffer[0] = 0x70;
2498                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2499                 /* ILLEGAL REQUEST */
2500                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2501                 /* LOGICAL UNIT NOT SUPPORTED */
2502                 buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2503                 break;
2504         case TCM_UNSUPPORTED_SCSI_OPCODE:
2505         case TCM_SECTOR_COUNT_TOO_MANY:
2506                 /* CURRENT ERROR */
2507                 buffer[0] = 0x70;
2508                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2509                 /* ILLEGAL REQUEST */
2510                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2511                 /* INVALID COMMAND OPERATION CODE */
2512                 buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2513                 break;
2514         case TCM_UNKNOWN_MODE_PAGE:
2515                 /* CURRENT ERROR */
2516                 buffer[0] = 0x70;
2517                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2518                 /* ILLEGAL REQUEST */
2519                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2520                 /* INVALID FIELD IN CDB */
2521                 buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2522                 break;
2523         case TCM_CHECK_CONDITION_ABORT_CMD:
2524                 /* CURRENT ERROR */
2525                 buffer[0] = 0x70;
2526                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2527                 /* ABORTED COMMAND */
2528                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2529                 /* BUS DEVICE RESET FUNCTION OCCURRED */
2530                 buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2531                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2532                 break;
2533         case TCM_INCORRECT_AMOUNT_OF_DATA:
2534                 /* CURRENT ERROR */
2535                 buffer[0] = 0x70;
2536                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2537                 /* ABORTED COMMAND */
2538                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2539                 /* WRITE ERROR */
2540                 buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2541                 /* NOT ENOUGH UNSOLICITED DATA */
2542                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2543                 break;
2544         case TCM_INVALID_CDB_FIELD:
2545                 /* CURRENT ERROR */
2546                 buffer[0] = 0x70;
2547                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2548                 /* ILLEGAL REQUEST */
2549                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2550                 /* INVALID FIELD IN CDB */
2551                 buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2552                 break;
2553         case TCM_INVALID_PARAMETER_LIST:
2554                 /* CURRENT ERROR */
2555                 buffer[0] = 0x70;
2556                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2557                 /* ILLEGAL REQUEST */
2558                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2559                 /* INVALID FIELD IN PARAMETER LIST */
2560                 buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2561                 break;
2562         case TCM_PARAMETER_LIST_LENGTH_ERROR:
2563                 /* CURRENT ERROR */
2564                 buffer[0] = 0x70;
2565                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2566                 /* ILLEGAL REQUEST */
2567                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2568                 /* PARAMETER LIST LENGTH ERROR */
2569                 buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2570                 break;
2571         case TCM_UNEXPECTED_UNSOLICITED_DATA:
2572                 /* CURRENT ERROR */
2573                 buffer[0] = 0x70;
2574                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2575                 /* ABORTED COMMAND */
2576                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2577                 /* WRITE ERROR */
2578                 buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2579                 /* UNEXPECTED_UNSOLICITED_DATA */
2580                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2581                 break;
2582         case TCM_SERVICE_CRC_ERROR:
2583                 /* CURRENT ERROR */
2584                 buffer[0] = 0x70;
2585                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2586                 /* ABORTED COMMAND */
2587                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2588                 /* PROTOCOL SERVICE CRC ERROR */
2589                 buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2590                 /* N/A */
2591                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2592                 break;
2593         case TCM_SNACK_REJECTED:
2594                 /* CURRENT ERROR */
2595                 buffer[0] = 0x70;
2596                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2597                 /* ABORTED COMMAND */
2598                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2599                 /* READ ERROR */
2600                 buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2601                 /* FAILED RETRANSMISSION REQUEST */
2602                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2603                 break;
2604         case TCM_WRITE_PROTECTED:
2605                 /* CURRENT ERROR */
2606                 buffer[0] = 0x70;
2607                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2608                 /* DATA PROTECT */
2609                 buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2610                 /* WRITE PROTECTED */
2611                 buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2612                 break;
2613         case TCM_ADDRESS_OUT_OF_RANGE:
2614                 /* CURRENT ERROR */
2615                 buffer[0] = 0x70;
2616                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2617                 /* ILLEGAL REQUEST */
2618                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2619                 /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2620                 buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2621                 break;
2622         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2623                 /* CURRENT ERROR */
2624                 buffer[0] = 0x70;
2625                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2626                 /* UNIT ATTENTION */
2627                 buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2628                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2629                 buffer[SPC_ASC_KEY_OFFSET] = asc;
2630                 buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2631                 break;
2632         case TCM_CHECK_CONDITION_NOT_READY:
2633                 /* CURRENT ERROR */
2634                 buffer[0] = 0x70;
2635                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2636                 /* Not Ready */
2637                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2638                 transport_get_sense_codes(cmd, &asc, &ascq);
2639                 buffer[SPC_ASC_KEY_OFFSET] = asc;
2640                 buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2641                 break;
2642         case TCM_MISCOMPARE_VERIFY:
2643                 /* CURRENT ERROR */
2644                 buffer[0] = 0x70;
2645                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2646                 buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2647                 /* MISCOMPARE DURING VERIFY OPERATION */
2648                 buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2649                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2650                 break;
2651         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2652         default:
2653                 /* CURRENT ERROR */
2654                 buffer[0] = 0x70;
2655                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2656                 /*
2657                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2658                  * Solaris initiators.  Returning NOT READY instead means the
2659                  * operations will be retried a finite number of times and we
2660                  * can survive intermittent errors.
2661                  */
2662                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2663                 /* LOGICAL UNIT COMMUNICATION FAILURE */
2664                 buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2665                 break;
2666         }
2667         /*
2668          * This code uses linux/include/scsi/scsi.h SAM status codes!
2669          */
2670         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2671         /*
2672          * Automatically padded, this value is encoded in the fabric's
2673          * data_length response PDU containing the SCSI defined sense data.
2674          */
2675         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2676
2677 after_reason:
2678         trace_target_cmd_complete(cmd);
2679         return cmd->se_tfo->queue_status(cmd);
2680 }
2681 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2682
2683 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2684 {
2685         if (!(cmd->transport_state & CMD_T_ABORTED))
2686                 return 0;
2687
2688         if (!send_status || (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
2689                 return 1;
2690
2691         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2692                  cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2693
2694         cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
2695         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2696         trace_target_cmd_complete(cmd);
2697         cmd->se_tfo->queue_status(cmd);
2698
2699         return 1;
2700 }
2701 EXPORT_SYMBOL(transport_check_aborted_status);
2702
2703 void transport_send_task_abort(struct se_cmd *cmd)
2704 {
2705         unsigned long flags;
2706
2707         spin_lock_irqsave(&cmd->t_state_lock, flags);
2708         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION | SCF_SENT_DELAYED_TAS)) {
2709                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2710                 return;
2711         }
2712         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2713
2714         /*
2715          * If there are still expected incoming fabric WRITEs, we wait
2716          * until until they have completed before sending a TASK_ABORTED
2717          * response.  This response with TASK_ABORTED status will be
2718          * queued back to fabric module by transport_check_aborted_status().
2719          */
2720         if (cmd->data_direction == DMA_TO_DEVICE) {
2721                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2722                         cmd->transport_state |= CMD_T_ABORTED;
2723                         smp_mb__after_atomic_inc();
2724                         return;
2725                 }
2726         }
2727         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2728
2729         transport_lun_remove_cmd(cmd);
2730
2731         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2732                 " ITT: 0x%08x\n", cmd->t_task_cdb[0],
2733                 cmd->se_tfo->get_task_tag(cmd));
2734
2735         trace_target_cmd_complete(cmd);
2736         cmd->se_tfo->queue_status(cmd);
2737 }
2738
2739 static void target_tmr_work(struct work_struct *work)
2740 {
2741         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2742         struct se_device *dev = cmd->se_dev;
2743         struct se_tmr_req *tmr = cmd->se_tmr_req;
2744         int ret;
2745
2746         switch (tmr->function) {
2747         case TMR_ABORT_TASK:
2748                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
2749                 break;
2750         case TMR_ABORT_TASK_SET:
2751         case TMR_CLEAR_ACA:
2752         case TMR_CLEAR_TASK_SET:
2753                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2754                 break;
2755         case TMR_LUN_RESET:
2756                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2757                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2758                                          TMR_FUNCTION_REJECTED;
2759                 break;
2760         case TMR_TARGET_WARM_RESET:
2761                 tmr->response = TMR_FUNCTION_REJECTED;
2762                 break;
2763         case TMR_TARGET_COLD_RESET:
2764                 tmr->response = TMR_FUNCTION_REJECTED;
2765                 break;
2766         default:
2767                 pr_err("Uknown TMR function: 0x%02x.\n",
2768                                 tmr->function);
2769                 tmr->response = TMR_FUNCTION_REJECTED;
2770                 break;
2771         }
2772
2773         cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2774         cmd->se_tfo->queue_tm_rsp(cmd);
2775
2776         transport_cmd_check_stop_to_fabric(cmd);
2777 }
2778
2779 int transport_generic_handle_tmr(
2780         struct se_cmd *cmd)
2781 {
2782         INIT_WORK(&cmd->work, target_tmr_work);
2783         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2784         return 0;
2785 }
2786 EXPORT_SYMBOL(transport_generic_handle_tmr);