drivers/target/target_core_transport.c

   1 /*******************************************************************************
   2  * Filename:  target_core_transport.c
   3  *
   4  * This file contains the Generic Target Engine Core.
   5  *
   6  * (c) Copyright 2002-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/net.h>
  27 #include <linux/delay.h>
  28 #include <linux/string.h>
  29 #include <linux/timer.h>
  30 #include <linux/slab.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/kthread.h>
  33 #include <linux/in.h>
  34 #include <linux/cdrom.h>
  35 #include <linux/module.h>
  36 #include <linux/ratelimit.h>
  37 #include <linux/vmalloc.h>
  38 #include <asm/unaligned.h>
  39 #include <net/sock.h>
  40 #include <net/tcp.h>
  41 #include <scsi/scsi_proto.h>
  42
  43 #include <target/target_core_base.h>
  44 #include <target/target_core_backend.h>
  45 #include <target/target_core_fabric.h>
  46
  47 #include "target_core_internal.h"
  48 #include "target_core_alua.h"
  49 #include "target_core_pr.h"
  50 #include "target_core_ua.h"
  51
  52 #define CREATE_TRACE_POINTS
  53 #include <trace/events/target.h>
  54
  55 static struct workqueue_struct *target_completion_wq;
  56 static struct kmem_cache *se_sess_cache;
  57 struct kmem_cache *se_ua_cache;
  58 struct kmem_cache *t10_pr_reg_cache;
  59 struct kmem_cache *t10_alua_lu_gp_cache;
  60 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  61 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  62 struct kmem_cache *t10_alua_lba_map_cache;
  63 struct kmem_cache *t10_alua_lba_map_mem_cache;
  64
  65 static void transport_complete_task_attr(struct se_cmd *cmd);
  66 static void transport_handle_queue_full(struct se_cmd *cmd,
  67                 struct se_device *dev);
  68 static int transport_put_cmd(struct se_cmd *cmd);
  69 static void target_complete_ok_work(struct work_struct *work);
  70
  71 int init_se_kmem_caches(void)
  72 {
  73         se_sess_cache = kmem_cache_create("se_sess_cache",
  74                         sizeof(struct se_session), __alignof__(struct se_session),
  75                         0, NULL);
  76         if (!se_sess_cache) {
  77                 pr_err("kmem_cache_create() for struct se_session"
  78                                 " failed\n");
  79                 goto out;
  80         }
  81         se_ua_cache = kmem_cache_create("se_ua_cache",
  82                         sizeof(struct se_ua), __alignof__(struct se_ua),
  83                         0, NULL);
  84         if (!se_ua_cache) {
  85                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  86                 goto out_free_sess_cache;
  87         }
  88         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  89                         sizeof(struct t10_pr_registration),
  90                         __alignof__(struct t10_pr_registration), 0, NULL);
  91         if (!t10_pr_reg_cache) {
  92                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  93                                 " failed\n");
  94                 goto out_free_ua_cache;
  95         }
  96         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  97                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  98                         0, NULL);
  99         if (!t10_alua_lu_gp_cache) {
 100                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 101                                 " failed\n");
 102                 goto out_free_pr_reg_cache;
 103         }
 104         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 105                         sizeof(struct t10_alua_lu_gp_member),
 106                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 107         if (!t10_alua_lu_gp_mem_cache) {
 108                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 109                                 "cache failed\n");
 110                 goto out_free_lu_gp_cache;
 111         }
 112         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 113                         sizeof(struct t10_alua_tg_pt_gp),
 114                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 115         if (!t10_alua_tg_pt_gp_cache) {
 116                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 117                                 "cache failed\n");
 118                 goto out_free_lu_gp_mem_cache;
 119         }
 120         t10_alua_lba_map_cache = kmem_cache_create(
 121                         "t10_alua_lba_map_cache",
 122                         sizeof(struct t10_alua_lba_map),
 123                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 124         if (!t10_alua_lba_map_cache) {
 125                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 126                                 "cache failed\n");
 127                 goto out_free_tg_pt_gp_cache;
 128         }
 129         t10_alua_lba_map_mem_cache = kmem_cache_create(
 130                         "t10_alua_lba_map_mem_cache",
 131                         sizeof(struct t10_alua_lba_map_member),
 132                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 133         if (!t10_alua_lba_map_mem_cache) {
 134                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 135                                 "cache failed\n");
 136                 goto out_free_lba_map_cache;
 137         }
 138
 139         target_completion_wq = alloc_workqueue("target_completion",
 140                                                WQ_MEM_RECLAIM, 0);
 141         if (!target_completion_wq)
 142                 goto out_free_lba_map_mem_cache;
 143
 144         return 0;
 145
 146 out_free_lba_map_mem_cache:
 147         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 148 out_free_lba_map_cache:
 149         kmem_cache_destroy(t10_alua_lba_map_cache);
 150 out_free_tg_pt_gp_cache:
 151         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 152 out_free_lu_gp_mem_cache:
 153         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 154 out_free_lu_gp_cache:
 155         kmem_cache_destroy(t10_alua_lu_gp_cache);
 156 out_free_pr_reg_cache:
 157         kmem_cache_destroy(t10_pr_reg_cache);
 158 out_free_ua_cache:
 159         kmem_cache_destroy(se_ua_cache);
 160 out_free_sess_cache:
 161         kmem_cache_destroy(se_sess_cache);
 162 out:
 163         return -ENOMEM;
 164 }
 165
 166 void release_se_kmem_caches(void)
 167 {
 168         destroy_workqueue(target_completion_wq);
 169         kmem_cache_destroy(se_sess_cache);
 170         kmem_cache_destroy(se_ua_cache);
 171         kmem_cache_destroy(t10_pr_reg_cache);
 172         kmem_cache_destroy(t10_alua_lu_gp_cache);
 173         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 174         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 175         kmem_cache_destroy(t10_alua_lba_map_cache);
 176         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 177 }
 178
 179 /* This code ensures unique mib indexes are handed out. */
 180 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 181 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 182
 183 /*
 184  * Allocate a new row index for the entry type specified
 185  */
 186 u32 scsi_get_new_index(scsi_index_t type)
 187 {
 188         u32 new_index;
 189
 190         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 191
 192         spin_lock(&scsi_mib_index_lock);
 193         new_index = ++scsi_mib_index[type];
 194         spin_unlock(&scsi_mib_index_lock);
 195
 196         return new_index;
 197 }
 198
 199 void transport_subsystem_check_init(void)
 200 {
 201         int ret;
 202         static int sub_api_initialized;
 203
 204         if (sub_api_initialized)
 205                 return;
 206
 207         ret = request_module("target_core_iblock");
 208         if (ret != 0)
 209                 pr_err("Unable to load target_core_iblock\n");
 210
 211         ret = request_module("target_core_file");
 212         if (ret != 0)
 213                 pr_err("Unable to load target_core_file\n");
 214
 215         ret = request_module("target_core_pscsi");
 216         if (ret != 0)
 217                 pr_err("Unable to load target_core_pscsi\n");
 218
 219         ret = request_module("target_core_user");
 220         if (ret != 0)
 221                 pr_err("Unable to load target_core_user\n");
 222
 223         sub_api_initialized = 1;
 224 }
 225
 226 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
 227 {
 228         struct se_session *se_sess;
 229
 230         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 231         if (!se_sess) {
 232                 pr_err("Unable to allocate struct se_session from"
 233                                 " se_sess_cache\n");
 234                 return ERR_PTR(-ENOMEM);
 235         }
 236         INIT_LIST_HEAD(&se_sess->sess_list);
 237         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 238         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 239         INIT_LIST_HEAD(&se_sess->sess_wait_list);
 240         spin_lock_init(&se_sess->sess_cmd_lock);
 241         kref_init(&se_sess->sess_kref);
 242         se_sess->sup_prot_ops = sup_prot_ops;
 243
 244         return se_sess;
 245 }
 246 EXPORT_SYMBOL(transport_init_session);
 247
 248 int transport_alloc_session_tags(struct se_session *se_sess,
 249                                  unsigned int tag_num, unsigned int tag_size)
 250 {
 251         int rc;
 252
 253         se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
 254                                         GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
 255         if (!se_sess->sess_cmd_map) {
 256                 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
 257                 if (!se_sess->sess_cmd_map) {
 258                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 259                         return -ENOMEM;
 260                 }
 261         }
 262
 263         rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
 264         if (rc < 0) {
 265                 pr_err("Unable to init se_sess->sess_tag_pool,"
 266                         " tag_num: %u\n", tag_num);
 267                 kvfree(se_sess->sess_cmd_map);
 268                 se_sess->sess_cmd_map = NULL;
 269                 return -ENOMEM;
 270         }
 271
 272         return 0;
 273 }
 274 EXPORT_SYMBOL(transport_alloc_session_tags);
 275
 276 struct se_session *transport_init_session_tags(unsigned int tag_num,
 277                                                unsigned int tag_size,
 278                                                enum target_prot_op sup_prot_ops)
 279 {
 280         struct se_session *se_sess;
 281         int rc;
 282
 283         se_sess = transport_init_session(sup_prot_ops);
 284         if (IS_ERR(se_sess))
 285                 return se_sess;
 286
 287         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 288         if (rc < 0) {
 289                 transport_free_session(se_sess);
 290                 return ERR_PTR(-ENOMEM);
 291         }
 292
 293         return se_sess;
 294 }
 295 EXPORT_SYMBOL(transport_init_session_tags);
 296
 297 /*
 298  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 299  */
 300 void __transport_register_session(
 301         struct se_portal_group *se_tpg,
 302         struct se_node_acl *se_nacl,
 303         struct se_session *se_sess,
 304         void *fabric_sess_ptr)
 305 {
 306         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 307         unsigned char buf[PR_REG_ISID_LEN];
 308
 309         se_sess->se_tpg = se_tpg;
 310         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 311         /*
 312          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 313          *
 314          * Only set for struct se_session's that will actually be moving I/O.
 315          * eg: *NOT* discovery sessions.
 316          */
 317         if (se_nacl) {
 318                 /*
 319                  *
 320                  * Determine if fabric allows for T10-PI feature bits exposed to
 321                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 322                  *
 323                  * If so, then always save prot_type on a per se_node_acl node
 324                  * basis and re-instate the previous sess_prot_type to avoid
 325                  * disabling PI from below any previously initiator side
 326                  * registered LUNs.
 327                  */
 328                 if (se_nacl->saved_prot_type)
 329                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 330                 else if (tfo->tpg_check_prot_fabric_only)
 331                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 332                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 333                 /*
 334                  * If the fabric module supports an ISID based TransportID,
 335                  * save this value in binary from the fabric I_T Nexus now.
 336                  */
 337                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 338                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 339                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 340                                         &buf[0], PR_REG_ISID_LEN);
 341                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 342                 }
 343                 kref_get(&se_nacl->acl_kref);
 344
 345                 spin_lock_irq(&se_nacl->nacl_sess_lock);
 346                 /*
 347                  * The se_nacl->nacl_sess pointer will be set to the
 348                  * last active I_T Nexus for each struct se_node_acl.
 349                  */
 350                 se_nacl->nacl_sess = se_sess;
 351
 352                 list_add_tail(&se_sess->sess_acl_list,
 353                               &se_nacl->acl_sess_list);
 354                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
 355         }
 356         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 357
 358         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 359                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 360 }
 361 EXPORT_SYMBOL(__transport_register_session);
 362
 363 void transport_register_session(
 364         struct se_portal_group *se_tpg,
 365         struct se_node_acl *se_nacl,
 366         struct se_session *se_sess,
 367         void *fabric_sess_ptr)
 368 {
 369         unsigned long flags;
 370
 371         spin_lock_irqsave(&se_tpg->session_lock, flags);
 372         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 373         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 374 }
 375 EXPORT_SYMBOL(transport_register_session);
 376
 377 static void target_release_session(struct kref *kref)
 378 {
 379         struct se_session *se_sess = container_of(kref,
 380                         struct se_session, sess_kref);
 381         struct se_portal_group *se_tpg = se_sess->se_tpg;
 382
 383         se_tpg->se_tpg_tfo->close_session(se_sess);
 384 }
 385
 386 void target_get_session(struct se_session *se_sess)
 387 {
 388         kref_get(&se_sess->sess_kref);
 389 }
 390 EXPORT_SYMBOL(target_get_session);
 391
 392 void target_put_session(struct se_session *se_sess)
 393 {
 394         kref_put(&se_sess->sess_kref, target_release_session);
 395 }
 396 EXPORT_SYMBOL(target_put_session);
 397
 398 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 399 {
 400         struct se_session *se_sess;
 401         ssize_t len = 0;
 402
 403         spin_lock_bh(&se_tpg->session_lock);
 404         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 405                 if (!se_sess->se_node_acl)
 406                         continue;
 407                 if (!se_sess->se_node_acl->dynamic_node_acl)
 408                         continue;
 409                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 410                         break;
 411
 412                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 413                                 se_sess->se_node_acl->initiatorname);
 414                 len += 1; /* Include NULL terminator */
 415         }
 416         spin_unlock_bh(&se_tpg->session_lock);
 417
 418         return len;
 419 }
 420 EXPORT_SYMBOL(target_show_dynamic_sessions);
 421
 422 static void target_complete_nacl(struct kref *kref)
 423 {
 424         struct se_node_acl *nacl = container_of(kref,
 425                                 struct se_node_acl, acl_kref);
 426
 427         complete(&nacl->acl_free_comp);
 428 }
 429
 430 void target_put_nacl(struct se_node_acl *nacl)
 431 {
 432         kref_put(&nacl->acl_kref, target_complete_nacl);
 433 }
 434
 435 void transport_deregister_session_configfs(struct se_session *se_sess)
 436 {
 437         struct se_node_acl *se_nacl;
 438         unsigned long flags;
 439         /*
 440          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 441          */
 442         se_nacl = se_sess->se_node_acl;
 443         if (se_nacl) {
 444                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 445                 if (se_nacl->acl_stop == 0)
 446                         list_del(&se_sess->sess_acl_list);
 447                 /*
 448                  * If the session list is empty, then clear the pointer.
 449                  * Otherwise, set the struct se_session pointer from the tail
 450                  * element of the per struct se_node_acl active session list.
 451                  */
 452                 if (list_empty(&se_nacl->acl_sess_list))
 453                         se_nacl->nacl_sess = NULL;
 454                 else {
 455                         se_nacl->nacl_sess = container_of(
 456                                         se_nacl->acl_sess_list.prev,
 457                                         struct se_session, sess_acl_list);
 458                 }
 459                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 460         }
 461 }
 462 EXPORT_SYMBOL(transport_deregister_session_configfs);
 463
 464 void transport_free_session(struct se_session *se_sess)
 465 {
 466         if (se_sess->sess_cmd_map) {
 467                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 468                 kvfree(se_sess->sess_cmd_map);
 469         }
 470         kmem_cache_free(se_sess_cache, se_sess);
 471 }
 472 EXPORT_SYMBOL(transport_free_session);
 473
 474 void transport_deregister_session(struct se_session *se_sess)
 475 {
 476         struct se_portal_group *se_tpg = se_sess->se_tpg;
 477         const struct target_core_fabric_ops *se_tfo;
 478         struct se_node_acl *se_nacl;
 479         unsigned long flags;
 480         bool comp_nacl = true, drop_nacl = false;
 481
 482         if (!se_tpg) {
 483                 transport_free_session(se_sess);
 484                 return;
 485         }
 486         se_tfo = se_tpg->se_tpg_tfo;
 487
 488         spin_lock_irqsave(&se_tpg->session_lock, flags);
 489         list_del(&se_sess->sess_list);
 490         se_sess->se_tpg = NULL;
 491         se_sess->fabric_sess_ptr = NULL;
 492         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 493
 494         /*
 495          * Determine if we need to do extra work for this initiator node's
 496          * struct se_node_acl if it had been previously dynamically generated.
 497          */
 498         se_nacl = se_sess->se_node_acl;
 499
 500         mutex_lock(&se_tpg->acl_node_mutex);
 501         if (se_nacl && se_nacl->dynamic_node_acl) {
 502                 if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 503                         list_del(&se_nacl->acl_list);
 504                         se_tpg->num_node_acls--;
 505                         drop_nacl = true;
 506                 }
 507         }
 508         mutex_unlock(&se_tpg->acl_node_mutex);
 509
 510         if (drop_nacl) {
 511                 core_tpg_wait_for_nacl_pr_ref(se_nacl);
 512                 core_free_device_list_for_node(se_nacl, se_tpg);
 513                 kfree(se_nacl);
 514                 comp_nacl = false;
 515         }
 516         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 517                 se_tpg->se_tpg_tfo->get_fabric_name());
 518         /*
 519          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 520          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 521          * removal context.
 522          */
 523         if (se_nacl && comp_nacl)
 524                 target_put_nacl(se_nacl);
 525
 526         transport_free_session(se_sess);
 527 }
 528 EXPORT_SYMBOL(transport_deregister_session);
 529
 530 /*
 531  * Called with cmd->t_state_lock held.
 532  */
 533 static void target_remove_from_state_list(struct se_cmd *cmd)
 534 {
 535         struct se_device *dev = cmd->se_dev;
 536         unsigned long flags;
 537
 538         if (!dev)
 539                 return;
 540
 541         if (cmd->transport_state & CMD_T_BUSY)
 542                 return;
 543
 544         spin_lock_irqsave(&dev->execute_task_lock, flags);
 545         if (cmd->state_active) {
 546                 list_del(&cmd->state_list);
 547                 cmd->state_active = false;
 548         }
 549         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 550 }
 551
 552 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 553                                     bool write_pending)
 554 {
 555         unsigned long flags;
 556
 557         spin_lock_irqsave(&cmd->t_state_lock, flags);
 558         if (write_pending)
 559                 cmd->t_state = TRANSPORT_WRITE_PENDING;
 560
 561         if (remove_from_lists) {
 562                 target_remove_from_state_list(cmd);
 563
 564                 /*
 565                  * Clear struct se_cmd->se_lun before the handoff to FE.
 566                  */
 567                 cmd->se_lun = NULL;
 568         }
 569
 570         /*
 571          * Determine if frontend context caller is requesting the stopping of
 572          * this command for frontend exceptions.
 573          */
 574         if (cmd->transport_state & CMD_T_STOP) {
 575                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 576                         __func__, __LINE__, cmd->tag);
 577
 578                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 579
 580                 complete_all(&cmd->t_transport_stop_comp);
 581                 return 1;
 582         }
 583
 584         cmd->transport_state &= ~CMD_T_ACTIVE;
 585         if (remove_from_lists) {
 586                 /*
 587                  * Some fabric modules like tcm_loop can release
 588                  * their internally allocated I/O reference now and
 589                  * struct se_cmd now.
 590                  *
 591                  * Fabric modules are expected to return '1' here if the
 592                  * se_cmd being passed is released at this point,
 593                  * or zero if not being released.
 594                  */
 595                 if (cmd->se_tfo->check_stop_free != NULL) {
 596                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 597                         return cmd->se_tfo->check_stop_free(cmd);
 598                 }
 599         }
 600
 601         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 602         return 0;
 603 }
 604
 605 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 606 {
 607         return transport_cmd_check_stop(cmd, true, false);
 608 }
 609
 610 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 611 {
 612         struct se_lun *lun = cmd->se_lun;
 613
 614         if (!lun)
 615                 return;
 616
 617         if (cmpxchg(&cmd->lun_ref_active, true, false))
 618                 percpu_ref_put(&lun->lun_ref);
 619 }
 620
 621 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 622 {
 623         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 624                 transport_lun_remove_cmd(cmd);
 625         /*
 626          * Allow the fabric driver to unmap any resources before
 627          * releasing the descriptor via TFO->release_cmd()
 628          */
 629         if (remove)
 630                 cmd->se_tfo->aborted_task(cmd);
 631
 632         if (transport_cmd_check_stop_to_fabric(cmd))
 633                 return;
 634         if (remove)
 635                 transport_put_cmd(cmd);
 636 }
 637
 638 static void target_complete_failure_work(struct work_struct *work)
 639 {
 640         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 641
 642         transport_generic_request_failure(cmd,
 643                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 644 }
 645
 646 /*
 647  * Used when asking transport to copy Sense Data from the underlying
 648  * Linux/SCSI struct scsi_cmnd
 649  */
 650 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 651 {
 652         struct se_device *dev = cmd->se_dev;
 653
 654         WARN_ON(!cmd->se_lun);
 655
 656         if (!dev)
 657                 return NULL;
 658
 659         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 660                 return NULL;
 661
 662         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 663
 664         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 665                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 666         return cmd->sense_buffer;
 667 }
 668
 669 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 670 {
 671         struct se_device *dev = cmd->se_dev;
 672         int success = scsi_status == GOOD;
 673         unsigned long flags;
 674
 675         cmd->scsi_status = scsi_status;
 676
 677
 678         spin_lock_irqsave(&cmd->t_state_lock, flags);
 679         cmd->transport_state &= ~CMD_T_BUSY;
 680
 681         if (dev && dev->transport->transport_complete) {
 682                 dev->transport->transport_complete(cmd,
 683                                 cmd->t_data_sg,
 684                                 transport_get_sense_buffer(cmd));
 685                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 686                         success = 1;
 687         }
 688
 689         /*
 690          * See if we are waiting to complete for an exception condition.
 691          */
 692         if (cmd->transport_state & CMD_T_REQUEST_STOP) {
 693                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 694                 complete(&cmd->task_stop_comp);
 695                 return;
 696         }
 697
 698         /*
 699          * Check for case where an explicit ABORT_TASK has been received
 700          * and transport_wait_for_tasks() will be waiting for completion..
 701          */
 702         if (cmd->transport_state & CMD_T_ABORTED &&
 703             cmd->transport_state & CMD_T_STOP) {
 704                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 705                 complete_all(&cmd->t_transport_stop_comp);
 706                 return;
 707         } else if (!success) {
 708                 INIT_WORK(&cmd->work, target_complete_failure_work);
 709         } else {
 710                 INIT_WORK(&cmd->work, target_complete_ok_work);
 711         }
 712
 713         cmd->t_state = TRANSPORT_COMPLETE;
 714         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 715         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 716
 717         queue_work(target_completion_wq, &cmd->work);
 718 }
 719 EXPORT_SYMBOL(target_complete_cmd);
 720
 721 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 722 {
 723         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 724                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 725                         cmd->residual_count += cmd->data_length - length;
 726                 } else {
 727                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 728                         cmd->residual_count = cmd->data_length - length;
 729                 }
 730
 731                 cmd->data_length = length;
 732         }
 733
 734         target_complete_cmd(cmd, scsi_status);
 735 }
 736 EXPORT_SYMBOL(target_complete_cmd_with_length);
 737
 738 static void target_add_to_state_list(struct se_cmd *cmd)
 739 {
 740         struct se_device *dev = cmd->se_dev;
 741         unsigned long flags;
 742
 743         spin_lock_irqsave(&dev->execute_task_lock, flags);
 744         if (!cmd->state_active) {
 745                 list_add_tail(&cmd->state_list, &dev->state_list);
 746                 cmd->state_active = true;
 747         }
 748         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 749 }
 750
 751 /*
 752  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 753  */
 754 static void transport_write_pending_qf(struct se_cmd *cmd);
 755 static void transport_complete_qf(struct se_cmd *cmd);
 756
 757 void target_qf_do_work(struct work_struct *work)
 758 {
 759         struct se_device *dev = container_of(work, struct se_device,
 760                                         qf_work_queue);
 761         LIST_HEAD(qf_cmd_list);
 762         struct se_cmd *cmd, *cmd_tmp;
 763
 764         spin_lock_irq(&dev->qf_cmd_lock);
 765         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 766         spin_unlock_irq(&dev->qf_cmd_lock);
 767
 768         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 769                 list_del(&cmd->se_qf_node);
 770                 atomic_dec_mb(&dev->dev_qf_count);
 771
 772                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 773                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 774                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 775                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 776                         : "UNKNOWN");
 777
 778                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 779                         transport_write_pending_qf(cmd);
 780                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 781                         transport_complete_qf(cmd);
 782         }
 783 }
 784
 785 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 786 {
 787         switch (cmd->data_direction) {
 788         case DMA_NONE:
 789                 return "NONE";
 790         case DMA_FROM_DEVICE:
 791                 return "READ";
 792         case DMA_TO_DEVICE:
 793                 return "WRITE";
 794         case DMA_BIDIRECTIONAL:
 795                 return "BIDI";
 796         default:
 797                 break;
 798         }
 799
 800         return "UNKNOWN";
 801 }
 802
 803 void transport_dump_dev_state(
 804         struct se_device *dev,
 805         char *b,
 806         int *bl)
 807 {
 808         *bl += sprintf(b + *bl, "Status: ");
 809         if (dev->export_count)
 810                 *bl += sprintf(b + *bl, "ACTIVATED");
 811         else
 812                 *bl += sprintf(b + *bl, "DEACTIVATED");
 813
 814         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 815         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 816                 dev->dev_attrib.block_size,
 817                 dev->dev_attrib.hw_max_sectors);
 818         *bl += sprintf(b + *bl, "        ");
 819 }
 820
 821 void transport_dump_vpd_proto_id(
 822         struct t10_vpd *vpd,
 823         unsigned char *p_buf,
 824         int p_buf_len)
 825 {
 826         unsigned char buf[VPD_TMP_BUF_SIZE];
 827         int len;
 828
 829         memset(buf, 0, VPD_TMP_BUF_SIZE);
 830         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 831
 832         switch (vpd->protocol_identifier) {
 833         case 0x00:
 834                 sprintf(buf+len, "Fibre Channel\n");
 835                 break;
 836         case 0x10:
 837                 sprintf(buf+len, "Parallel SCSI\n");
 838                 break;
 839         case 0x20:
 840                 sprintf(buf+len, "SSA\n");
 841                 break;
 842         case 0x30:
 843                 sprintf(buf+len, "IEEE 1394\n");
 844                 break;
 845         case 0x40:
 846                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 847                                 " Protocol\n");
 848                 break;
 849         case 0x50:
 850                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 851                 break;
 852         case 0x60:
 853                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 854                 break;
 855         case 0x70:
 856                 sprintf(buf+len, "Automation/Drive Interface Transport"
 857                                 " Protocol\n");
 858                 break;
 859         case 0x80:
 860                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 861                 break;
 862         default:
 863                 sprintf(buf+len, "Unknown 0x%02x\n",
 864                                 vpd->protocol_identifier);
 865                 break;
 866         }
 867
 868         if (p_buf)
 869                 strncpy(p_buf, buf, p_buf_len);
 870         else
 871                 pr_debug("%s", buf);
 872 }
 873
 874 void
 875 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 876 {
 877         /*
 878          * Check if the Protocol Identifier Valid (PIV) bit is set..
 879          *
 880          * from spc3r23.pdf section 7.5.1
 881          */
 882          if (page_83[1] & 0x80) {
 883                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 884                 vpd->protocol_identifier_set = 1;
 885                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 886         }
 887 }
 888 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 889
 890 int transport_dump_vpd_assoc(
 891         struct t10_vpd *vpd,
 892         unsigned char *p_buf,
 893         int p_buf_len)
 894 {
 895         unsigned char buf[VPD_TMP_BUF_SIZE];
 896         int ret = 0;
 897         int len;
 898
 899         memset(buf, 0, VPD_TMP_BUF_SIZE);
 900         len = sprintf(buf, "T10 VPD Identifier Association: ");
 901
 902         switch (vpd->association) {
 903         case 0x00:
 904                 sprintf(buf+len, "addressed logical unit\n");
 905                 break;
 906         case 0x10:
 907                 sprintf(buf+len, "target port\n");
 908                 break;
 909         case 0x20:
 910                 sprintf(buf+len, "SCSI target device\n");
 911                 break;
 912         default:
 913                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 914                 ret = -EINVAL;
 915                 break;
 916         }
 917
 918         if (p_buf)
 919                 strncpy(p_buf, buf, p_buf_len);
 920         else
 921                 pr_debug("%s", buf);
 922
 923         return ret;
 924 }
 925
 926 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 927 {
 928         /*
 929          * The VPD identification association..
 930          *
 931          * from spc3r23.pdf Section 7.6.3.1 Table 297
 932          */
 933         vpd->association = (page_83[1] & 0x30);
 934         return transport_dump_vpd_assoc(vpd, NULL, 0);
 935 }
 936 EXPORT_SYMBOL(transport_set_vpd_assoc);
 937
 938 int transport_dump_vpd_ident_type(
 939         struct t10_vpd *vpd,
 940         unsigned char *p_buf,
 941         int p_buf_len)
 942 {
 943         unsigned char buf[VPD_TMP_BUF_SIZE];
 944         int ret = 0;
 945         int len;
 946
 947         memset(buf, 0, VPD_TMP_BUF_SIZE);
 948         len = sprintf(buf, "T10 VPD Identifier Type: ");
 949
 950         switch (vpd->device_identifier_type) {
 951         case 0x00:
 952                 sprintf(buf+len, "Vendor specific\n");
 953                 break;
 954         case 0x01:
 955                 sprintf(buf+len, "T10 Vendor ID based\n");
 956                 break;
 957         case 0x02:
 958                 sprintf(buf+len, "EUI-64 based\n");
 959                 break;
 960         case 0x03:
 961                 sprintf(buf+len, "NAA\n");
 962                 break;
 963         case 0x04:
 964                 sprintf(buf+len, "Relative target port identifier\n");
 965                 break;
 966         case 0x08:
 967                 sprintf(buf+len, "SCSI name string\n");
 968                 break;
 969         default:
 970                 sprintf(buf+len, "Unsupported: 0x%02x\n",
 971                                 vpd->device_identifier_type);
 972                 ret = -EINVAL;
 973                 break;
 974         }
 975
 976         if (p_buf) {
 977                 if (p_buf_len < strlen(buf)+1)
 978                         return -EINVAL;
 979                 strncpy(p_buf, buf, p_buf_len);
 980         } else {
 981                 pr_debug("%s", buf);
 982         }
 983
 984         return ret;
 985 }
 986
 987 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
 988 {
 989         /*
 990          * The VPD identifier type..
 991          *
 992          * from spc3r23.pdf Section 7.6.3.1 Table 298
 993          */
 994         vpd->device_identifier_type = (page_83[1] & 0x0f);
 995         return transport_dump_vpd_ident_type(vpd, NULL, 0);
 996 }
 997 EXPORT_SYMBOL(transport_set_vpd_ident_type);
 998
 999 int transport_dump_vpd_ident(
1000         struct t10_vpd *vpd,
1001         unsigned char *p_buf,
1002         int p_buf_len)
1003 {
1004         unsigned char buf[VPD_TMP_BUF_SIZE];
1005         int ret = 0;
1006
1007         memset(buf, 0, VPD_TMP_BUF_SIZE);
1008
1009         switch (vpd->device_identifier_code_set) {
1010         case 0x01: /* Binary */
1011                 snprintf(buf, sizeof(buf),
1012                         "T10 VPD Binary Device Identifier: %s\n",
1013                         &vpd->device_identifier[0]);
1014                 break;
1015         case 0x02: /* ASCII */
1016                 snprintf(buf, sizeof(buf),
1017                         "T10 VPD ASCII Device Identifier: %s\n",
1018                         &vpd->device_identifier[0]);
1019                 break;
1020         case 0x03: /* UTF-8 */
1021                 snprintf(buf, sizeof(buf),
1022                         "T10 VPD UTF-8 Device Identifier: %s\n",
1023                         &vpd->device_identifier[0]);
1024                 break;
1025         default:
1026                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1027                         " 0x%02x", vpd->device_identifier_code_set);
1028                 ret = -EINVAL;
1029                 break;
1030         }
1031
1032         if (p_buf)
1033                 strncpy(p_buf, buf, p_buf_len);
1034         else
1035                 pr_debug("%s", buf);
1036
1037         return ret;
1038 }
1039
1040 int
1041 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1042 {
1043         static const char hex_str[] = "0123456789abcdef";
1044         int j = 0, i = 4; /* offset to start of the identifier */
1045
1046         /*
1047          * The VPD Code Set (encoding)
1048          *
1049          * from spc3r23.pdf Section 7.6.3.1 Table 296
1050          */
1051         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1052         switch (vpd->device_identifier_code_set) {
1053         case 0x01: /* Binary */
1054                 vpd->device_identifier[j++] =
1055                                 hex_str[vpd->device_identifier_type];
1056                 while (i < (4 + page_83[3])) {
1057                         vpd->device_identifier[j++] =
1058                                 hex_str[(page_83[i] & 0xf0) >> 4];
1059                         vpd->device_identifier[j++] =
1060                                 hex_str[page_83[i] & 0x0f];
1061                         i++;
1062                 }
1063                 break;
1064         case 0x02: /* ASCII */
1065         case 0x03: /* UTF-8 */
1066                 while (i < (4 + page_83[3]))
1067                         vpd->device_identifier[j++] = page_83[i++];
1068                 break;
1069         default:
1070                 break;
1071         }
1072
1073         return transport_dump_vpd_ident(vpd, NULL, 0);
1074 }
1075 EXPORT_SYMBOL(transport_set_vpd_ident);
1076
1077 sense_reason_t
1078 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1079 {
1080         struct se_device *dev = cmd->se_dev;
1081
1082         if (cmd->unknown_data_length) {
1083                 cmd->data_length = size;
1084         } else if (size != cmd->data_length) {
1085                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1086                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1087                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1088                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1089
1090                 if (cmd->data_direction == DMA_TO_DEVICE) {
1091                         pr_err("Rejecting underflow/overflow"
1092                                         " WRITE data\n");
1093                         return TCM_INVALID_CDB_FIELD;
1094                 }
1095                 /*
1096                  * Reject READ_* or WRITE_* with overflow/underflow for
1097                  * type SCF_SCSI_DATA_CDB.
1098                  */
1099                 if (dev->dev_attrib.block_size != 512)  {
1100                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1101                                 " CDB on non 512-byte sector setup subsystem"
1102                                 " plugin: %s\n", dev->transport->name);
1103                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1104                         return TCM_INVALID_CDB_FIELD;
1105                 }
1106                 /*
1107                  * For the overflow case keep the existing fabric provided
1108                  * ->data_length.  Otherwise for the underflow case, reset
1109                  * ->data_length to the smaller SCSI expected data transfer
1110                  * length.
1111                  */
1112                 if (size > cmd->data_length) {
1113                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1114                         cmd->residual_count = (size - cmd->data_length);
1115                 } else {
1116                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1117                         cmd->residual_count = (cmd->data_length - size);
1118                         cmd->data_length = size;
1119                 }
1120         }
1121
1122         return 0;
1123
1124 }
1125
1126 /*
1127  * Used by fabric modules containing a local struct se_cmd within their
1128  * fabric dependent per I/O descriptor.
1129  *
1130  * Preserves the value of @cmd->tag.
1131  */
1132 void transport_init_se_cmd(
1133         struct se_cmd *cmd,
1134         const struct target_core_fabric_ops *tfo,
1135         struct se_session *se_sess,
1136         u32 data_length,
1137         int data_direction,
1138         int task_attr,
1139         unsigned char *sense_buffer)
1140 {
1141         INIT_LIST_HEAD(&cmd->se_delayed_node);
1142         INIT_LIST_HEAD(&cmd->se_qf_node);
1143         INIT_LIST_HEAD(&cmd->se_cmd_list);
1144         INIT_LIST_HEAD(&cmd->state_list);
1145         init_completion(&cmd->t_transport_stop_comp);
1146         init_completion(&cmd->cmd_wait_comp);
1147         init_completion(&cmd->task_stop_comp);
1148         spin_lock_init(&cmd->t_state_lock);
1149         kref_init(&cmd->cmd_kref);
1150         cmd->transport_state = CMD_T_DEV_ACTIVE;
1151
1152         cmd->se_tfo = tfo;
1153         cmd->se_sess = se_sess;
1154         cmd->data_length = data_length;
1155         cmd->data_direction = data_direction;
1156         cmd->sam_task_attr = task_attr;
1157         cmd->sense_buffer = sense_buffer;
1158
1159         cmd->state_active = false;
1160 }
1161 EXPORT_SYMBOL(transport_init_se_cmd);
1162
1163 static sense_reason_t
1164 transport_check_alloc_task_attr(struct se_cmd *cmd)
1165 {
1166         struct se_device *dev = cmd->se_dev;
1167
1168         /*
1169          * Check if SAM Task Attribute emulation is enabled for this
1170          * struct se_device storage object
1171          */
1172         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1173                 return 0;
1174
1175         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1176                 pr_debug("SAM Task Attribute ACA"
1177                         " emulation is not supported\n");
1178                 return TCM_INVALID_CDB_FIELD;
1179         }
1180         /*
1181          * Used to determine when ORDERED commands should go from
1182          * Dormant to Active status.
1183          */
1184         cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1185         pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1186                         cmd->se_ordered_id, cmd->sam_task_attr,
1187                         dev->transport->name);
1188         return 0;
1189 }
1190
1191 sense_reason_t
1192 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1193 {
1194         struct se_device *dev = cmd->se_dev;
1195         sense_reason_t ret;
1196
1197         /*
1198          * Ensure that the received CDB is less than the max (252 + 8) bytes
1199          * for VARIABLE_LENGTH_CMD
1200          */
1201         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1202                 pr_err("Received SCSI CDB with command_size: %d that"
1203                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1204                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1205                 return TCM_INVALID_CDB_FIELD;
1206         }
1207         /*
1208          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1209          * allocate the additional extended CDB buffer now..  Otherwise
1210          * setup the pointer from __t_task_cdb to t_task_cdb.
1211          */
1212         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1213                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1214                                                 GFP_KERNEL);
1215                 if (!cmd->t_task_cdb) {
1216                         pr_err("Unable to allocate cmd->t_task_cdb"
1217                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1218                                 scsi_command_size(cdb),
1219                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1220                         return TCM_OUT_OF_RESOURCES;
1221                 }
1222         } else
1223                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1224         /*
1225          * Copy the original CDB into cmd->
1226          */
1227         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1228
1229         trace_target_sequencer_start(cmd);
1230
1231         /*
1232          * Check for an existing UNIT ATTENTION condition
1233          */
1234         ret = target_scsi3_ua_check(cmd);
1235         if (ret)
1236                 return ret;
1237
1238         ret = target_alua_state_check(cmd);
1239         if (ret)
1240                 return ret;
1241
1242         ret = target_check_reservation(cmd);
1243         if (ret) {
1244                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1245                 return ret;
1246         }
1247
1248         ret = dev->transport->parse_cdb(cmd);
1249         if (ret)
1250                 return ret;
1251
1252         ret = transport_check_alloc_task_attr(cmd);
1253         if (ret)
1254                 return ret;
1255
1256         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1257         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1258         return 0;
1259 }
1260 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1261
1262 /*
1263  * Used by fabric module frontends to queue tasks directly.
1264  * Many only be used from process context only
1265  */
1266 int transport_handle_cdb_direct(
1267         struct se_cmd *cmd)
1268 {
1269         sense_reason_t ret;
1270
1271         if (!cmd->se_lun) {
1272                 dump_stack();
1273                 pr_err("cmd->se_lun is NULL\n");
1274                 return -EINVAL;
1275         }
1276         if (in_interrupt()) {
1277                 dump_stack();
1278                 pr_err("transport_generic_handle_cdb cannot be called"
1279                                 " from interrupt context\n");
1280                 return -EINVAL;
1281         }
1282         /*
1283          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1284          * outstanding descriptors are handled correctly during shutdown via
1285          * transport_wait_for_tasks()
1286          *
1287          * Also, we don't take cmd->t_state_lock here as we only expect
1288          * this to be called for initial descriptor submission.
1289          */
1290         cmd->t_state = TRANSPORT_NEW_CMD;
1291         cmd->transport_state |= CMD_T_ACTIVE;
1292
1293         /*
1294          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1295          * so follow TRANSPORT_NEW_CMD processing thread context usage
1296          * and call transport_generic_request_failure() if necessary..
1297          */
1298         ret = transport_generic_new_cmd(cmd);
1299         if (ret)
1300                 transport_generic_request_failure(cmd, ret);
1301         return 0;
1302 }
1303 EXPORT_SYMBOL(transport_handle_cdb_direct);
1304
1305 sense_reason_t
1306 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1307                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1308 {
1309         if (!sgl || !sgl_count)
1310                 return 0;
1311
1312         /*
1313          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1314          * scatterlists already have been set to follow what the fabric
1315          * passes for the original expected data transfer length.
1316          */
1317         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1318                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1319                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1320                 return TCM_INVALID_CDB_FIELD;
1321         }
1322
1323         cmd->t_data_sg = sgl;
1324         cmd->t_data_nents = sgl_count;
1325         cmd->t_bidi_data_sg = sgl_bidi;
1326         cmd->t_bidi_data_nents = sgl_bidi_count;
1327
1328         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1329         return 0;
1330 }
1331
1332 /*
1333  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1334  *                       se_cmd + use pre-allocated SGL memory.
1335  *
1336  * @se_cmd: command descriptor to submit
1337  * @se_sess: associated se_sess for endpoint
1338  * @cdb: pointer to SCSI CDB
1339  * @sense: pointer to SCSI sense buffer
1340  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1341  * @data_length: fabric expected data transfer length
1342  * @task_addr: SAM task attribute
1343  * @data_dir: DMA data direction
1344  * @flags: flags for command submission from target_sc_flags_tables
1345  * @sgl: struct scatterlist memory for unidirectional mapping
1346  * @sgl_count: scatterlist count for unidirectional mapping
1347  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1348  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1349  * @sgl_prot: struct scatterlist memory protection information
1350  * @sgl_prot_count: scatterlist count for protection information
1351  *
1352  * Task tags are supported if the caller has set @se_cmd->tag.
1353  *
1354  * Returns non zero to signal active I/O shutdown failure.  All other
1355  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1356  * but still return zero here.
1357  *
1358  * This may only be called from process context, and also currently
1359  * assumes internal allocation of fabric payload buffer by target-core.
1360  */
1361 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1362                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1363                 u32 data_length, int task_attr, int data_dir, int flags,
1364                 struct scatterlist *sgl, u32 sgl_count,
1365                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1366                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1367 {
1368         struct se_portal_group *se_tpg;
1369         sense_reason_t rc;
1370         int ret;
1371
1372         se_tpg = se_sess->se_tpg;
1373         BUG_ON(!se_tpg);
1374         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1375         BUG_ON(in_interrupt());
1376         /*
1377          * Initialize se_cmd for target operation.  From this point
1378          * exceptions are handled by sending exception status via
1379          * target_core_fabric_ops->queue_status() callback
1380          */
1381         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1382                                 data_length, data_dir, task_attr, sense);
1383         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1384                 se_cmd->unknown_data_length = 1;
1385         /*
1386          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1387          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1388          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1389          * kref_put() to happen during fabric packet acknowledgement.
1390          */
1391         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1392         if (ret)
1393                 return ret;
1394         /*
1395          * Signal bidirectional data payloads to target-core
1396          */
1397         if (flags & TARGET_SCF_BIDI_OP)
1398                 se_cmd->se_cmd_flags |= SCF_BIDI;
1399         /*
1400          * Locate se_lun pointer and attach it to struct se_cmd
1401          */
1402         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1403         if (rc) {
1404                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1405                 target_put_sess_cmd(se_cmd);
1406                 return 0;
1407         }
1408
1409         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1410         if (rc != 0) {
1411                 transport_generic_request_failure(se_cmd, rc);
1412                 return 0;
1413         }
1414
1415         /*
1416          * Save pointers for SGLs containing protection information,
1417          * if present.
1418          */
1419         if (sgl_prot_count) {
1420                 se_cmd->t_prot_sg = sgl_prot;
1421                 se_cmd->t_prot_nents = sgl_prot_count;
1422                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1423         }
1424
1425         /*
1426          * When a non zero sgl_count has been passed perform SGL passthrough
1427          * mapping for pre-allocated fabric memory instead of having target
1428          * core perform an internal SGL allocation..
1429          */
1430         if (sgl_count != 0) {
1431                 BUG_ON(!sgl);
1432
1433                 /*
1434                  * A work-around for tcm_loop as some userspace code via
1435                  * scsi-generic do not memset their associated read buffers,
1436                  * so go ahead and do that here for type non-data CDBs.  Also
1437                  * note that this is currently guaranteed to be a single SGL
1438                  * for this case by target core in target_setup_cmd_from_cdb()
1439                  * -> transport_generic_cmd_sequencer().
1440                  */
1441                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1442                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1443                         unsigned char *buf = NULL;
1444
1445                         if (sgl)
1446                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1447
1448                         if (buf) {
1449                                 memset(buf, 0, sgl->length);
1450                                 kunmap(sg_page(sgl));
1451                         }
1452                 }
1453
1454                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1455                                 sgl_bidi, sgl_bidi_count);
1456                 if (rc != 0) {
1457                         transport_generic_request_failure(se_cmd, rc);
1458                         return 0;
1459                 }
1460         }
1461
1462         /*
1463          * Check if we need to delay processing because of ALUA
1464          * Active/NonOptimized primary access state..
1465          */
1466         core_alua_check_nonop_delay(se_cmd);
1467
1468         transport_handle_cdb_direct(se_cmd);
1469         return 0;
1470 }
1471 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1472
1473 /*
1474  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1475  *
1476  * @se_cmd: command descriptor to submit
1477  * @se_sess: associated se_sess for endpoint
1478  * @cdb: pointer to SCSI CDB
1479  * @sense: pointer to SCSI sense buffer
1480  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1481  * @data_length: fabric expected data transfer length
1482  * @task_addr: SAM task attribute
1483  * @data_dir: DMA data direction
1484  * @flags: flags for command submission from target_sc_flags_tables
1485  *
1486  * Task tags are supported if the caller has set @se_cmd->tag.
1487  *
1488  * Returns non zero to signal active I/O shutdown failure.  All other
1489  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1490  * but still return zero here.
1491  *
1492  * This may only be called from process context, and also currently
1493  * assumes internal allocation of fabric payload buffer by target-core.
1494  *
1495  * It also assumes interal target core SGL memory allocation.
1496  */
1497 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1498                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1499                 u32 data_length, int task_attr, int data_dir, int flags)
1500 {
1501         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1502                         unpacked_lun, data_length, task_attr, data_dir,
1503                         flags, NULL, 0, NULL, 0, NULL, 0);
1504 }
1505 EXPORT_SYMBOL(target_submit_cmd);
1506
1507 static void target_complete_tmr_failure(struct work_struct *work)
1508 {
1509         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1510
1511         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1512         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1513
1514         transport_cmd_check_stop_to_fabric(se_cmd);
1515 }
1516
1517 /**
1518  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1519  *                     for TMR CDBs
1520  *
1521  * @se_cmd: command descriptor to submit
1522  * @se_sess: associated se_sess for endpoint
1523  * @sense: pointer to SCSI sense buffer
1524  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1525  * @fabric_context: fabric context for TMR req
1526  * @tm_type: Type of TM request
1527  * @gfp: gfp type for caller
1528  * @tag: referenced task tag for TMR_ABORT_TASK
1529  * @flags: submit cmd flags
1530  *
1531  * Callable from all contexts.
1532  **/
1533
1534 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1535                 unsigned char *sense, u64 unpacked_lun,
1536                 void *fabric_tmr_ptr, unsigned char tm_type,
1537                 gfp_t gfp, unsigned int tag, int flags)
1538 {
1539         struct se_portal_group *se_tpg;
1540         int ret;
1541
1542         se_tpg = se_sess->se_tpg;
1543         BUG_ON(!se_tpg);
1544
1545         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1546                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1547         /*
1548          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1549          * allocation failure.
1550          */
1551         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1552         if (ret < 0)
1553                 return -ENOMEM;
1554
1555         if (tm_type == TMR_ABORT_TASK)
1556                 se_cmd->se_tmr_req->ref_task_tag = tag;
1557
1558         /* See target_submit_cmd for commentary */
1559         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1560         if (ret) {
1561                 core_tmr_release_req(se_cmd->se_tmr_req);
1562                 return ret;
1563         }
1564
1565         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1566         if (ret) {
1567                 /*
1568                  * For callback during failure handling, push this work off
1569                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1570                  */
1571                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1572                 schedule_work(&se_cmd->work);
1573                 return 0;
1574         }
1575         transport_generic_handle_tmr(se_cmd);
1576         return 0;
1577 }
1578 EXPORT_SYMBOL(target_submit_tmr);
1579
1580 /*
1581  * If the cmd is active, request it to be stopped and sleep until it
1582  * has completed.
1583  */
1584 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1585         __releases(&cmd->t_state_lock)
1586         __acquires(&cmd->t_state_lock)
1587 {
1588         bool was_active = false;
1589
1590         if (cmd->transport_state & CMD_T_BUSY) {
1591                 cmd->transport_state |= CMD_T_REQUEST_STOP;
1592                 spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1593
1594                 pr_debug("cmd %p waiting to complete\n", cmd);
1595                 wait_for_completion(&cmd->task_stop_comp);
1596                 pr_debug("cmd %p stopped successfully\n", cmd);
1597
1598                 spin_lock_irqsave(&cmd->t_state_lock, *flags);
1599                 cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1600                 cmd->transport_state &= ~CMD_T_BUSY;
1601                 was_active = true;
1602         }
1603
1604         return was_active;
1605 }
1606
1607 /*
1608  * Handle SAM-esque emulation for generic transport request failures.
1609  */
1610 void transport_generic_request_failure(struct se_cmd *cmd,
1611                 sense_reason_t sense_reason)
1612 {
1613         int ret = 0;
1614
1615         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1616                 " CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1617         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1618                 cmd->se_tfo->get_cmd_state(cmd),
1619                 cmd->t_state, sense_reason);
1620         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1621                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1622                 (cmd->transport_state & CMD_T_STOP) != 0,
1623                 (cmd->transport_state & CMD_T_SENT) != 0);
1624
1625         /*
1626          * For SAM Task Attribute emulation for failed struct se_cmd
1627          */
1628         transport_complete_task_attr(cmd);
1629         /*
1630          * Handle special case for COMPARE_AND_WRITE failure, where the
1631          * callback is expected to drop the per device ->caw_sem.
1632          */
1633         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1634              cmd->transport_complete_callback)
1635                 cmd->transport_complete_callback(cmd, false);
1636
1637         switch (sense_reason) {
1638         case TCM_NON_EXISTENT_LUN:
1639         case TCM_UNSUPPORTED_SCSI_OPCODE:
1640         case TCM_INVALID_CDB_FIELD:
1641         case TCM_INVALID_PARAMETER_LIST:
1642         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1643         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1644         case TCM_UNKNOWN_MODE_PAGE:
1645         case TCM_WRITE_PROTECTED:
1646         case TCM_ADDRESS_OUT_OF_RANGE:
1647         case TCM_CHECK_CONDITION_ABORT_CMD:
1648         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1649         case TCM_CHECK_CONDITION_NOT_READY:
1650         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1651         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1652         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1653                 break;
1654         case TCM_OUT_OF_RESOURCES:
1655                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1656                 break;
1657         case TCM_RESERVATION_CONFLICT:
1658                 /*
1659                  * No SENSE Data payload for this case, set SCSI Status
1660                  * and queue the response to $FABRIC_MOD.
1661                  *
1662                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1663                  */
1664                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1665                 /*
1666                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1667                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1668                  * CONFLICT STATUS.
1669                  *
1670                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1671                  */
1672                 if (cmd->se_sess &&
1673                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1674                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1675                                                cmd->orig_fe_lun, 0x2C,
1676                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1677                 }
1678                 trace_target_cmd_complete(cmd);
1679                 ret = cmd->se_tfo->queue_status(cmd);
1680                 if (ret == -EAGAIN || ret == -ENOMEM)
1681                         goto queue_full;
1682                 goto check_stop;
1683         default:
1684                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1685                         cmd->t_task_cdb[0], sense_reason);
1686                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1687                 break;
1688         }
1689
1690         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1691         if (ret == -EAGAIN || ret == -ENOMEM)
1692                 goto queue_full;
1693
1694 check_stop:
1695         transport_lun_remove_cmd(cmd);
1696         if (!transport_cmd_check_stop_to_fabric(cmd))
1697                 ;
1698         return;
1699
1700 queue_full:
1701         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1702         transport_handle_queue_full(cmd, cmd->se_dev);
1703 }
1704 EXPORT_SYMBOL(transport_generic_request_failure);
1705
1706 void __target_execute_cmd(struct se_cmd *cmd)
1707 {
1708         sense_reason_t ret;
1709
1710         if (cmd->execute_cmd) {
1711                 ret = cmd->execute_cmd(cmd);
1712                 if (ret) {
1713                         spin_lock_irq(&cmd->t_state_lock);
1714                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1715                         spin_unlock_irq(&cmd->t_state_lock);
1716
1717                         transport_generic_request_failure(cmd, ret);
1718                 }
1719         }
1720 }
1721
1722 static int target_write_prot_action(struct se_cmd *cmd)
1723 {
1724         u32 sectors;
1725         /*
1726          * Perform WRITE_INSERT of PI using software emulation when backend
1727          * device has PI enabled, if the transport has not already generated
1728          * PI using hardware WRITE_INSERT offload.
1729          */
1730         switch (cmd->prot_op) {
1731         case TARGET_PROT_DOUT_INSERT:
1732                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1733                         sbc_dif_generate(cmd);
1734                 break;
1735         case TARGET_PROT_DOUT_STRIP:
1736                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1737                         break;
1738
1739                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1740                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1741                                              sectors, 0, cmd->t_prot_sg, 0);
1742                 if (unlikely(cmd->pi_err)) {
1743                         spin_lock_irq(&cmd->t_state_lock);
1744                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1745                         spin_unlock_irq(&cmd->t_state_lock);
1746                         transport_generic_request_failure(cmd, cmd->pi_err);
1747                         return -1;
1748                 }
1749                 break;
1750         default:
1751                 break;
1752         }
1753
1754         return 0;
1755 }
1756
1757 static bool target_handle_task_attr(struct se_cmd *cmd)
1758 {
1759         struct se_device *dev = cmd->se_dev;
1760
1761         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1762                 return false;
1763
1764         /*
1765          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1766          * to allow the passed struct se_cmd list of tasks to the front of the list.
1767          */
1768         switch (cmd->sam_task_attr) {
1769         case TCM_HEAD_TAG:
1770                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1771                          "se_ordered_id: %u\n",
1772                          cmd->t_task_cdb[0], cmd->se_ordered_id);
1773                 return false;
1774         case TCM_ORDERED_TAG:
1775                 atomic_inc_mb(&dev->dev_ordered_sync);
1776
1777                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1778                          " se_ordered_id: %u\n",
1779                          cmd->t_task_cdb[0], cmd->se_ordered_id);
1780
1781                 /*
1782                  * Execute an ORDERED command if no other older commands
1783                  * exist that need to be completed first.
1784                  */
1785                 if (!atomic_read(&dev->simple_cmds))
1786                         return false;
1787                 break;
1788         default:
1789                 /*
1790                  * For SIMPLE and UNTAGGED Task Attribute commands
1791                  */
1792                 atomic_inc_mb(&dev->simple_cmds);
1793                 break;
1794         }
1795
1796         if (atomic_read(&dev->dev_ordered_sync) == 0)
1797                 return false;
1798
1799         spin_lock(&dev->delayed_cmd_lock);
1800         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1801         spin_unlock(&dev->delayed_cmd_lock);
1802
1803         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1804                 " delayed CMD list, se_ordered_id: %u\n",
1805                 cmd->t_task_cdb[0], cmd->sam_task_attr,
1806                 cmd->se_ordered_id);
1807         return true;
1808 }
1809
1810 void target_execute_cmd(struct se_cmd *cmd)
1811 {
1812         /*
1813          * If the received CDB has aleady been aborted stop processing it here.
1814          */
1815         if (transport_check_aborted_status(cmd, 1))
1816                 return;
1817
1818         /*
1819          * Determine if frontend context caller is requesting the stopping of
1820          * this command for frontend exceptions.
1821          */
1822         spin_lock_irq(&cmd->t_state_lock);
1823         if (cmd->transport_state & CMD_T_STOP) {
1824                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1825                         __func__, __LINE__, cmd->tag);
1826
1827                 spin_unlock_irq(&cmd->t_state_lock);
1828                 complete_all(&cmd->t_transport_stop_comp);
1829                 return;
1830         }
1831
1832         cmd->t_state = TRANSPORT_PROCESSING;
1833         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1834         spin_unlock_irq(&cmd->t_state_lock);
1835
1836         if (target_write_prot_action(cmd))
1837                 return;
1838
1839         if (target_handle_task_attr(cmd)) {
1840                 spin_lock_irq(&cmd->t_state_lock);
1841                 cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1842                 spin_unlock_irq(&cmd->t_state_lock);
1843                 return;
1844         }
1845
1846         __target_execute_cmd(cmd);
1847 }
1848 EXPORT_SYMBOL(target_execute_cmd);
1849
1850 /*
1851  * Process all commands up to the last received ORDERED task attribute which
1852  * requires another blocking boundary
1853  */
1854 static void target_restart_delayed_cmds(struct se_device *dev)
1855 {
1856         for (;;) {
1857                 struct se_cmd *cmd;
1858
1859                 spin_lock(&dev->delayed_cmd_lock);
1860                 if (list_empty(&dev->delayed_cmd_list)) {
1861                         spin_unlock(&dev->delayed_cmd_lock);
1862                         break;
1863                 }
1864
1865                 cmd = list_entry(dev->delayed_cmd_list.next,
1866                                  struct se_cmd, se_delayed_node);
1867                 list_del(&cmd->se_delayed_node);
1868                 spin_unlock(&dev->delayed_cmd_lock);
1869
1870                 __target_execute_cmd(cmd);
1871
1872                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1873                         break;
1874         }
1875 }
1876
1877 /*
1878  * Called from I/O completion to determine which dormant/delayed
1879  * and ordered cmds need to have their tasks added to the execution queue.
1880  */
1881 static void transport_complete_task_attr(struct se_cmd *cmd)
1882 {
1883         struct se_device *dev = cmd->se_dev;
1884
1885         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1886                 return;
1887
1888         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1889                 atomic_dec_mb(&dev->simple_cmds);
1890                 dev->dev_cur_ordered_id++;
1891                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1892                         " SIMPLE: %u\n", dev->dev_cur_ordered_id,
1893                         cmd->se_ordered_id);
1894         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1895                 dev->dev_cur_ordered_id++;
1896                 pr_debug("Incremented dev_cur_ordered_id: %u for"
1897                         " HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1898                         cmd->se_ordered_id);
1899         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1900                 atomic_dec_mb(&dev->dev_ordered_sync);
1901
1902                 dev->dev_cur_ordered_id++;
1903                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1904                         " %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1905         }
1906
1907         target_restart_delayed_cmds(dev);
1908 }
1909
1910 static void transport_complete_qf(struct se_cmd *cmd)
1911 {
1912         int ret = 0;
1913
1914         transport_complete_task_attr(cmd);
1915
1916         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1917                 trace_target_cmd_complete(cmd);
1918                 ret = cmd->se_tfo->queue_status(cmd);
1919                 goto out;
1920         }
1921
1922         switch (cmd->data_direction) {
1923         case DMA_FROM_DEVICE:
1924                 trace_target_cmd_complete(cmd);
1925                 ret = cmd->se_tfo->queue_data_in(cmd);
1926                 break;
1927         case DMA_TO_DEVICE:
1928                 if (cmd->se_cmd_flags & SCF_BIDI) {
1929                         ret = cmd->se_tfo->queue_data_in(cmd);
1930                         break;
1931                 }
1932                 /* Fall through for DMA_TO_DEVICE */
1933         case DMA_NONE:
1934                 trace_target_cmd_complete(cmd);
1935                 ret = cmd->se_tfo->queue_status(cmd);
1936                 break;
1937         default:
1938                 break;
1939         }
1940
1941 out:
1942         if (ret < 0) {
1943                 transport_handle_queue_full(cmd, cmd->se_dev);
1944                 return;
1945         }
1946         transport_lun_remove_cmd(cmd);
1947         transport_cmd_check_stop_to_fabric(cmd);
1948 }
1949
1950 static void transport_handle_queue_full(
1951         struct se_cmd *cmd,
1952         struct se_device *dev)
1953 {
1954         spin_lock_irq(&dev->qf_cmd_lock);
1955         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1956         atomic_inc_mb(&dev->dev_qf_count);
1957         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1958
1959         schedule_work(&cmd->se_dev->qf_work_queue);
1960 }
1961
1962 static bool target_read_prot_action(struct se_cmd *cmd)
1963 {
1964         switch (cmd->prot_op) {
1965         case TARGET_PROT_DIN_STRIP:
1966                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
1967                         u32 sectors = cmd->data_length >>
1968                                   ilog2(cmd->se_dev->dev_attrib.block_size);
1969
1970                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1971                                                      sectors, 0, cmd->t_prot_sg,
1972                                                      0);
1973                         if (cmd->pi_err)
1974                                 return true;
1975                 }
1976                 break;
1977         case TARGET_PROT_DIN_INSERT:
1978                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
1979                         break;
1980
1981                 sbc_dif_generate(cmd);
1982                 break;
1983         default:
1984                 break;
1985         }
1986
1987         return false;
1988 }
1989
1990 static void target_complete_ok_work(struct work_struct *work)
1991 {
1992         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1993         int ret;
1994
1995         /*
1996          * Check if we need to move delayed/dormant tasks from cmds on the
1997          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1998          * Attribute.
1999          */
2000         transport_complete_task_attr(cmd);
2001
2002         /*
2003          * Check to schedule QUEUE_FULL work, or execute an existing
2004          * cmd->transport_qf_callback()
2005          */
2006         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2007                 schedule_work(&cmd->se_dev->qf_work_queue);
2008
2009         /*
2010          * Check if we need to send a sense buffer from
2011          * the struct se_cmd in question.
2012          */
2013         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2014                 WARN_ON(!cmd->scsi_status);
2015                 ret = transport_send_check_condition_and_sense(
2016                                         cmd, 0, 1);
2017                 if (ret == -EAGAIN || ret == -ENOMEM)
2018                         goto queue_full;
2019
2020                 transport_lun_remove_cmd(cmd);
2021                 transport_cmd_check_stop_to_fabric(cmd);
2022                 return;
2023         }
2024         /*
2025          * Check for a callback, used by amongst other things
2026          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2027          */
2028         if (cmd->transport_complete_callback) {
2029                 sense_reason_t rc;
2030
2031                 rc = cmd->transport_complete_callback(cmd, true);
2032                 if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
2033                         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2034                             !cmd->data_length)
2035                                 goto queue_rsp;
2036
2037                         return;
2038                 } else if (rc) {
2039                         ret = transport_send_check_condition_and_sense(cmd,
2040                                                 rc, 0);
2041                         if (ret == -EAGAIN || ret == -ENOMEM)
2042                                 goto queue_full;
2043
2044                         transport_lun_remove_cmd(cmd);
2045                         transport_cmd_check_stop_to_fabric(cmd);
2046                         return;
2047                 }
2048         }
2049
2050 queue_rsp:
2051         switch (cmd->data_direction) {
2052         case DMA_FROM_DEVICE:
2053                 atomic_long_add(cmd->data_length,
2054                                 &cmd->se_lun->lun_stats.tx_data_octets);
2055                 /*
2056                  * Perform READ_STRIP of PI using software emulation when
2057                  * backend had PI enabled, if the transport will not be
2058                  * performing hardware READ_STRIP offload.
2059                  */
2060                 if (target_read_prot_action(cmd)) {
2061                         ret = transport_send_check_condition_and_sense(cmd,
2062                                                 cmd->pi_err, 0);
2063                         if (ret == -EAGAIN || ret == -ENOMEM)
2064                                 goto queue_full;
2065
2066                         transport_lun_remove_cmd(cmd);
2067                         transport_cmd_check_stop_to_fabric(cmd);
2068                         return;
2069                 }
2070
2071                 trace_target_cmd_complete(cmd);
2072                 ret = cmd->se_tfo->queue_data_in(cmd);
2073                 if (ret == -EAGAIN || ret == -ENOMEM)
2074                         goto queue_full;
2075                 break;
2076         case DMA_TO_DEVICE:
2077                 atomic_long_add(cmd->data_length,
2078                                 &cmd->se_lun->lun_stats.rx_data_octets);
2079                 /*
2080                  * Check if we need to send READ payload for BIDI-COMMAND
2081                  */
2082                 if (cmd->se_cmd_flags & SCF_BIDI) {
2083                         atomic_long_add(cmd->data_length,
2084                                         &cmd->se_lun->lun_stats.tx_data_octets);
2085                         ret = cmd->se_tfo->queue_data_in(cmd);
2086                         if (ret == -EAGAIN || ret == -ENOMEM)
2087                                 goto queue_full;
2088                         break;
2089                 }
2090                 /* Fall through for DMA_TO_DEVICE */
2091         case DMA_NONE:
2092                 trace_target_cmd_complete(cmd);
2093                 ret = cmd->se_tfo->queue_status(cmd);
2094                 if (ret == -EAGAIN || ret == -ENOMEM)
2095                         goto queue_full;
2096                 break;
2097         default:
2098                 break;
2099         }
2100
2101         transport_lun_remove_cmd(cmd);
2102         transport_cmd_check_stop_to_fabric(cmd);
2103         return;
2104
2105 queue_full:
2106         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2107                 " data_direction: %d\n", cmd, cmd->data_direction);
2108         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2109         transport_handle_queue_full(cmd, cmd->se_dev);
2110 }
2111
2112 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2113 {
2114         struct scatterlist *sg;
2115         int count;
2116
2117         for_each_sg(sgl, sg, nents, count)
2118                 __free_page(sg_page(sg));
2119
2120         kfree(sgl);
2121 }
2122
2123 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2124 {
2125         /*
2126          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2127          * emulation, and free + reset pointers if necessary..
2128          */
2129         if (!cmd->t_data_sg_orig)
2130                 return;
2131
2132         kfree(cmd->t_data_sg);
2133         cmd->t_data_sg = cmd->t_data_sg_orig;
2134         cmd->t_data_sg_orig = NULL;
2135         cmd->t_data_nents = cmd->t_data_nents_orig;
2136         cmd->t_data_nents_orig = 0;
2137 }
2138
2139 static inline void transport_free_pages(struct se_cmd *cmd)
2140 {
2141         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2142                 transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2143                 cmd->t_prot_sg = NULL;
2144                 cmd->t_prot_nents = 0;
2145         }
2146
2147         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2148                 /*
2149                  * Release special case READ buffer payload required for
2150                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2151                  */
2152                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2153                         transport_free_sgl(cmd->t_bidi_data_sg,
2154                                            cmd->t_bidi_data_nents);
2155                         cmd->t_bidi_data_sg = NULL;
2156                         cmd->t_bidi_data_nents = 0;
2157                 }
2158                 transport_reset_sgl_orig(cmd);
2159                 return;
2160         }
2161         transport_reset_sgl_orig(cmd);
2162
2163         transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2164         cmd->t_data_sg = NULL;
2165         cmd->t_data_nents = 0;
2166
2167         transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2168         cmd->t_bidi_data_sg = NULL;
2169         cmd->t_bidi_data_nents = 0;
2170 }
2171
2172 /**
2173  * transport_release_cmd - free a command
2174  * @cmd:       command to free
2175  *
2176  * This routine unconditionally frees a command, and reference counting
2177  * or list removal must be done in the caller.
2178  */
2179 static int transport_release_cmd(struct se_cmd *cmd)
2180 {
2181         BUG_ON(!cmd->se_tfo);
2182
2183         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2184                 core_tmr_release_req(cmd->se_tmr_req);
2185         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2186                 kfree(cmd->t_task_cdb);
2187         /*
2188          * If this cmd has been setup with target_get_sess_cmd(), drop
2189          * the kref and call ->release_cmd() in kref callback.
2190          */
2191         return target_put_sess_cmd(cmd);
2192 }
2193
2194 /**
2195  * transport_put_cmd - release a reference to a command
2196  * @cmd:       command to release
2197  *
2198  * This routine releases our reference to the command and frees it if possible.
2199  */
2200 static int transport_put_cmd(struct se_cmd *cmd)
2201 {
2202         transport_free_pages(cmd);
2203         return transport_release_cmd(cmd);
2204 }
2205
2206 void *transport_kmap_data_sg(struct se_cmd *cmd)
2207 {
2208         struct scatterlist *sg = cmd->t_data_sg;
2209         struct page **pages;
2210         int i;
2211
2212         /*
2213          * We need to take into account a possible offset here for fabrics like
2214          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2215          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2216          */
2217         if (!cmd->t_data_nents)
2218                 return NULL;
2219
2220         BUG_ON(!sg);
2221         if (cmd->t_data_nents == 1)
2222                 return kmap(sg_page(sg)) + sg->offset;
2223
2224         /* >1 page. use vmap */
2225         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2226         if (!pages)
2227                 return NULL;
2228
2229         /* convert sg[] to pages[] */
2230         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2231                 pages[i] = sg_page(sg);
2232         }
2233
2234         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2235         kfree(pages);
2236         if (!cmd->t_data_vmap)
2237                 return NULL;
2238
2239         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2240 }
2241 EXPORT_SYMBOL(transport_kmap_data_sg);
2242
2243 void transport_kunmap_data_sg(struct se_cmd *cmd)
2244 {
2245         if (!cmd->t_data_nents) {
2246                 return;
2247         } else if (cmd->t_data_nents == 1) {
2248                 kunmap(sg_page(cmd->t_data_sg));
2249                 return;
2250         }
2251
2252         vunmap(cmd->t_data_vmap);
2253         cmd->t_data_vmap = NULL;
2254 }
2255 EXPORT_SYMBOL(transport_kunmap_data_sg);
2256
2257 int
2258 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2259                  bool zero_page)
2260 {
2261         struct scatterlist *sg;
2262         struct page *page;
2263         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2264         unsigned int nent;
2265         int i = 0;
2266
2267         nent = DIV_ROUND_UP(length, PAGE_SIZE);
2268         sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2269         if (!sg)
2270                 return -ENOMEM;
2271
2272         sg_init_table(sg, nent);
2273
2274         while (length) {
2275                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2276                 page = alloc_page(GFP_KERNEL | zero_flag);
2277                 if (!page)
2278                         goto out;
2279
2280                 sg_set_page(&sg[i], page, page_len, 0);
2281                 length -= page_len;
2282                 i++;
2283         }
2284         *sgl = sg;
2285         *nents = nent;
2286         return 0;
2287
2288 out:
2289         while (i > 0) {
2290                 i--;
2291                 __free_page(sg_page(&sg[i]));
2292         }
2293         kfree(sg);
2294         return -ENOMEM;
2295 }
2296
2297 /*
2298  * Allocate any required resources to execute the command.  For writes we
2299  * might not have the payload yet, so notify the fabric via a call to
2300  * ->write_pending instead. Otherwise place it on the execution queue.
2301  */
2302 sense_reason_t
2303 transport_generic_new_cmd(struct se_cmd *cmd)
2304 {
2305         int ret = 0;
2306         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2307
2308         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2309             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2310                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2311                                        cmd->prot_length, true);
2312                 if (ret < 0)
2313                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2314         }
2315
2316         /*
2317          * Determine is the TCM fabric module has already allocated physical
2318          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2319          * beforehand.
2320          */
2321         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2322             cmd->data_length) {
2323
2324                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2325                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2326                         u32 bidi_length;
2327
2328                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2329                                 bidi_length = cmd->t_task_nolb *
2330                                               cmd->se_dev->dev_attrib.block_size;
2331                         else
2332                                 bidi_length = cmd->data_length;
2333
2334                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2335                                                &cmd->t_bidi_data_nents,
2336                                                bidi_length, zero_flag);
2337                         if (ret < 0)
2338                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2339                 }
2340
2341                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2342                                        cmd->data_length, zero_flag);
2343                 if (ret < 0)
2344                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2345         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2346                     cmd->data_length) {
2347                 /*
2348                  * Special case for COMPARE_AND_WRITE with fabrics
2349                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2350                  */
2351                 u32 caw_length = cmd->t_task_nolb *
2352                                  cmd->se_dev->dev_attrib.block_size;
2353
2354                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2355                                        &cmd->t_bidi_data_nents,
2356                                        caw_length, zero_flag);
2357                 if (ret < 0)
2358                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2359         }
2360         /*
2361          * If this command is not a write we can execute it right here,
2362          * for write buffers we need to notify the fabric driver first
2363          * and let it call back once the write buffers are ready.
2364          */
2365         target_add_to_state_list(cmd);
2366         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2367                 target_execute_cmd(cmd);
2368                 return 0;
2369         }
2370         transport_cmd_check_stop(cmd, false, true);
2371
2372         ret = cmd->se_tfo->write_pending(cmd);
2373         if (ret == -EAGAIN || ret == -ENOMEM)
2374                 goto queue_full;
2375
2376         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2377         WARN_ON(ret);
2378
2379         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2380
2381 queue_full:
2382         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2383         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2384         transport_handle_queue_full(cmd, cmd->se_dev);
2385         return 0;
2386 }
2387 EXPORT_SYMBOL(transport_generic_new_cmd);
2388
2389 static void transport_write_pending_qf(struct se_cmd *cmd)
2390 {
2391         int ret;
2392
2393         ret = cmd->se_tfo->write_pending(cmd);
2394         if (ret == -EAGAIN || ret == -ENOMEM) {
2395                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2396                          cmd);
2397                 transport_handle_queue_full(cmd, cmd->se_dev);
2398         }
2399 }
2400
2401 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2402 {
2403         unsigned long flags;
2404         int ret = 0;
2405
2406         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2407                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2408                          transport_wait_for_tasks(cmd);
2409
2410                 ret = transport_release_cmd(cmd);
2411         } else {
2412                 if (wait_for_tasks)
2413                         transport_wait_for_tasks(cmd);
2414                 /*
2415                  * Handle WRITE failure case where transport_generic_new_cmd()
2416                  * has already added se_cmd to state_list, but fabric has
2417                  * failed command before I/O submission.
2418                  */
2419                 if (cmd->state_active) {
2420                         spin_lock_irqsave(&cmd->t_state_lock, flags);
2421                         target_remove_from_state_list(cmd);
2422                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2423                 }
2424
2425                 if (cmd->se_lun)
2426                         transport_lun_remove_cmd(cmd);
2427
2428                 ret = transport_put_cmd(cmd);
2429         }
2430         return ret;
2431 }
2432 EXPORT_SYMBOL(transport_generic_free_cmd);
2433
2434 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2435  * @se_cmd:     command descriptor to add
2436  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2437  */
2438 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2439 {
2440         struct se_session *se_sess = se_cmd->se_sess;
2441         unsigned long flags;
2442         int ret = 0;
2443
2444         /*
2445          * Add a second kref if the fabric caller is expecting to handle
2446          * fabric acknowledgement that requires two target_put_sess_cmd()
2447          * invocations before se_cmd descriptor release.
2448          */
2449         if (ack_kref)
2450                 kref_get(&se_cmd->cmd_kref);
2451
2452         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2453         if (se_sess->sess_tearing_down) {
2454                 ret = -ESHUTDOWN;
2455                 goto out;
2456         }
2457         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2458 out:
2459         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2460
2461         if (ret && ack_kref)
2462                 target_put_sess_cmd(se_cmd);
2463
2464         return ret;
2465 }
2466 EXPORT_SYMBOL(target_get_sess_cmd);
2467
2468 static void target_release_cmd_kref(struct kref *kref)
2469                 __releases(&se_cmd->se_sess->sess_cmd_lock)
2470 {
2471         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2472         struct se_session *se_sess = se_cmd->se_sess;
2473
2474         if (list_empty(&se_cmd->se_cmd_list)) {
2475                 spin_unlock(&se_sess->sess_cmd_lock);
2476                 se_cmd->se_tfo->release_cmd(se_cmd);
2477                 return;
2478         }
2479         if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2480                 spin_unlock(&se_sess->sess_cmd_lock);
2481                 complete(&se_cmd->cmd_wait_comp);
2482                 return;
2483         }
2484         list_del(&se_cmd->se_cmd_list);
2485         spin_unlock(&se_sess->sess_cmd_lock);
2486
2487         se_cmd->se_tfo->release_cmd(se_cmd);
2488 }
2489
2490 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2491  * @se_cmd:     command descriptor to drop
2492  */
2493 int target_put_sess_cmd(struct se_cmd *se_cmd)
2494 {
2495         struct se_session *se_sess = se_cmd->se_sess;
2496
2497         if (!se_sess) {
2498                 se_cmd->se_tfo->release_cmd(se_cmd);
2499                 return 1;
2500         }
2501         return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2502                         &se_sess->sess_cmd_lock);
2503 }
2504 EXPORT_SYMBOL(target_put_sess_cmd);
2505
2506 /* target_sess_cmd_list_set_waiting - Flag all commands in
2507  *         sess_cmd_list to complete cmd_wait_comp.  Set
2508  *         sess_tearing_down so no more commands are queued.
2509  * @se_sess:    session to flag
2510  */
2511 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2512 {
2513         struct se_cmd *se_cmd;
2514         unsigned long flags;
2515
2516         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2517         if (se_sess->sess_tearing_down) {
2518                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2519                 return;
2520         }
2521         se_sess->sess_tearing_down = 1;
2522         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2523
2524         list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2525                 se_cmd->cmd_wait_set = 1;
2526
2527         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2528 }
2529 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2530
2531 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2532  * @se_sess:    session to wait for active I/O
2533  */
2534 void target_wait_for_sess_cmds(struct se_session *se_sess)
2535 {
2536         struct se_cmd *se_cmd, *tmp_cmd;
2537         unsigned long flags;
2538
2539         list_for_each_entry_safe(se_cmd, tmp_cmd,
2540                                 &se_sess->sess_wait_list, se_cmd_list) {
2541                 list_del(&se_cmd->se_cmd_list);
2542
2543                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2544                         " %d\n", se_cmd, se_cmd->t_state,
2545                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2546
2547                 wait_for_completion(&se_cmd->cmd_wait_comp);
2548                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2549                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2550                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2551
2552                 se_cmd->se_tfo->release_cmd(se_cmd);
2553         }
2554
2555         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2556         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2557         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2558
2559 }
2560 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2561
2562 void transport_clear_lun_ref(struct se_lun *lun)
2563 {
2564         percpu_ref_kill(&lun->lun_ref);
2565         wait_for_completion(&lun->lun_ref_comp);
2566 }
2567
2568 /**
2569  * transport_wait_for_tasks - wait for completion to occur
2570  * @cmd:        command to wait
2571  *
2572  * Called from frontend fabric context to wait for storage engine
2573  * to pause and/or release frontend generated struct se_cmd.
2574  */
2575 bool transport_wait_for_tasks(struct se_cmd *cmd)
2576 {
2577         unsigned long flags;
2578
2579         spin_lock_irqsave(&cmd->t_state_lock, flags);
2580         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2581             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2582                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2583                 return false;
2584         }
2585
2586         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2587             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2588                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2589                 return false;
2590         }
2591
2592         if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2593                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2594                 return false;
2595         }
2596
2597         cmd->transport_state |= CMD_T_STOP;
2598
2599         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d, t_state: %d, CMD_T_STOP\n",
2600                 cmd, cmd->tag, cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2601
2602         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2603
2604         wait_for_completion(&cmd->t_transport_stop_comp);
2605
2606         spin_lock_irqsave(&cmd->t_state_lock, flags);
2607         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2608
2609         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->t_transport_stop_comp) for ITT: 0x%08llx\n",
2610                 cmd->tag);
2611
2612         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2613
2614         return true;
2615 }
2616 EXPORT_SYMBOL(transport_wait_for_tasks);
2617
2618 static int transport_get_sense_codes(
2619         struct se_cmd *cmd,
2620         u8 *asc,
2621         u8 *ascq)
2622 {
2623         *asc = cmd->scsi_asc;
2624         *ascq = cmd->scsi_ascq;
2625
2626         return 0;
2627 }
2628
2629 static
2630 void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
2631 {
2632         /* Place failed LBA in sense data information descriptor 0. */
2633         buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
2634         buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
2635         buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
2636         buffer[SPC_VALIDITY_OFFSET] = 0x80;
2637
2638         /* Descriptor Information: failing sector */
2639         put_unaligned_be64(bad_sector, &buffer[12]);
2640 }
2641
2642 int
2643 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2644                 sense_reason_t reason, int from_transport)
2645 {
2646         unsigned char *buffer = cmd->sense_buffer;
2647         unsigned long flags;
2648         u8 asc = 0, ascq = 0;
2649
2650         spin_lock_irqsave(&cmd->t_state_lock, flags);
2651         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2652                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2653                 return 0;
2654         }
2655         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2656         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2657
2658         if (!reason && from_transport)
2659                 goto after_reason;
2660
2661         if (!from_transport)
2662                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2663
2664         /*
2665          * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2666          * SENSE KEY values from include/scsi/scsi.h
2667          */
2668         switch (reason) {
2669         case TCM_NO_SENSE:
2670                 /* CURRENT ERROR */
2671                 buffer[0] = 0x70;
2672                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2673                 /* Not Ready */
2674                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2675                 /* NO ADDITIONAL SENSE INFORMATION */
2676                 buffer[SPC_ASC_KEY_OFFSET] = 0;
2677                 buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2678                 break;
2679         case TCM_NON_EXISTENT_LUN:
2680                 /* CURRENT ERROR */
2681                 buffer[0] = 0x70;
2682                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2683                 /* ILLEGAL REQUEST */
2684                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2685                 /* LOGICAL UNIT NOT SUPPORTED */
2686                 buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2687                 break;
2688         case TCM_UNSUPPORTED_SCSI_OPCODE:
2689         case TCM_SECTOR_COUNT_TOO_MANY:
2690                 /* CURRENT ERROR */
2691                 buffer[0] = 0x70;
2692                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2693                 /* ILLEGAL REQUEST */
2694                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2695                 /* INVALID COMMAND OPERATION CODE */
2696                 buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2697                 break;
2698         case TCM_UNKNOWN_MODE_PAGE:
2699                 /* CURRENT ERROR */
2700                 buffer[0] = 0x70;
2701                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2702                 /* ILLEGAL REQUEST */
2703                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2704                 /* INVALID FIELD IN CDB */
2705                 buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2706                 break;
2707         case TCM_CHECK_CONDITION_ABORT_CMD:
2708                 /* CURRENT ERROR */
2709                 buffer[0] = 0x70;
2710                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2711                 /* ABORTED COMMAND */
2712                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2713                 /* BUS DEVICE RESET FUNCTION OCCURRED */
2714                 buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2715                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2716                 break;
2717         case TCM_INCORRECT_AMOUNT_OF_DATA:
2718                 /* CURRENT ERROR */
2719                 buffer[0] = 0x70;
2720                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2721                 /* ABORTED COMMAND */
2722                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2723                 /* WRITE ERROR */
2724                 buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2725                 /* NOT ENOUGH UNSOLICITED DATA */
2726                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2727                 break;
2728         case TCM_INVALID_CDB_FIELD:
2729                 /* CURRENT ERROR */
2730                 buffer[0] = 0x70;
2731                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2732                 /* ILLEGAL REQUEST */
2733                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2734                 /* INVALID FIELD IN CDB */
2735                 buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2736                 break;
2737         case TCM_INVALID_PARAMETER_LIST:
2738                 /* CURRENT ERROR */
2739                 buffer[0] = 0x70;
2740                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2741                 /* ILLEGAL REQUEST */
2742                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2743                 /* INVALID FIELD IN PARAMETER LIST */
2744                 buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2745                 break;
2746         case TCM_PARAMETER_LIST_LENGTH_ERROR:
2747                 /* CURRENT ERROR */
2748                 buffer[0] = 0x70;
2749                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2750                 /* ILLEGAL REQUEST */
2751                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2752                 /* PARAMETER LIST LENGTH ERROR */
2753                 buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2754                 break;
2755         case TCM_UNEXPECTED_UNSOLICITED_DATA:
2756                 /* CURRENT ERROR */
2757                 buffer[0] = 0x70;
2758                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2759                 /* ABORTED COMMAND */
2760                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2761                 /* WRITE ERROR */
2762                 buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2763                 /* UNEXPECTED_UNSOLICITED_DATA */
2764                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2765                 break;
2766         case TCM_SERVICE_CRC_ERROR:
2767                 /* CURRENT ERROR */
2768                 buffer[0] = 0x70;
2769                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2770                 /* ABORTED COMMAND */
2771                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2772                 /* PROTOCOL SERVICE CRC ERROR */
2773                 buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2774                 /* N/A */
2775                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2776                 break;
2777         case TCM_SNACK_REJECTED:
2778                 /* CURRENT ERROR */
2779                 buffer[0] = 0x70;
2780                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2781                 /* ABORTED COMMAND */
2782                 buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2783                 /* READ ERROR */
2784                 buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2785                 /* FAILED RETRANSMISSION REQUEST */
2786                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2787                 break;
2788         case TCM_WRITE_PROTECTED:
2789                 /* CURRENT ERROR */
2790                 buffer[0] = 0x70;
2791                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2792                 /* DATA PROTECT */
2793                 buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2794                 /* WRITE PROTECTED */
2795                 buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2796                 break;
2797         case TCM_ADDRESS_OUT_OF_RANGE:
2798                 /* CURRENT ERROR */
2799                 buffer[0] = 0x70;
2800                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2801                 /* ILLEGAL REQUEST */
2802                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2803                 /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2804                 buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2805                 break;
2806         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2807                 /* CURRENT ERROR */
2808                 buffer[0] = 0x70;
2809                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2810                 /* UNIT ATTENTION */
2811                 buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2812                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2813                 buffer[SPC_ASC_KEY_OFFSET] = asc;
2814                 buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2815                 break;
2816         case TCM_CHECK_CONDITION_NOT_READY:
2817                 /* CURRENT ERROR */
2818                 buffer[0] = 0x70;
2819                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2820                 /* Not Ready */
2821                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2822                 transport_get_sense_codes(cmd, &asc, &ascq);
2823                 buffer[SPC_ASC_KEY_OFFSET] = asc;
2824                 buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2825                 break;
2826         case TCM_MISCOMPARE_VERIFY:
2827                 /* CURRENT ERROR */
2828                 buffer[0] = 0x70;
2829                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2830                 buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2831                 /* MISCOMPARE DURING VERIFY OPERATION */
2832                 buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2833                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2834                 break;
2835         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2836                 /* CURRENT ERROR */
2837                 buffer[0] = 0x70;
2838                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2839                 /* ILLEGAL REQUEST */
2840                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2841                 /* LOGICAL BLOCK GUARD CHECK FAILED */
2842                 buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2843                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
2844                 transport_err_sector_info(buffer, cmd->bad_sector);
2845                 break;
2846         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2847                 /* CURRENT ERROR */
2848                 buffer[0] = 0x70;
2849                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2850                 /* ILLEGAL REQUEST */
2851                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2852                 /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2853                 buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2854                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
2855                 transport_err_sector_info(buffer, cmd->bad_sector);
2856                 break;
2857         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2858                 /* CURRENT ERROR */
2859                 buffer[0] = 0x70;
2860                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2861                 /* ILLEGAL REQUEST */
2862                 buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2863                 /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2864                 buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2865                 buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2866                 transport_err_sector_info(buffer, cmd->bad_sector);
2867                 break;
2868         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2869         default:
2870                 /* CURRENT ERROR */
2871                 buffer[0] = 0x70;
2872                 buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2873                 /*
2874                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2875                  * Solaris initiators.  Returning NOT READY instead means the
2876                  * operations will be retried a finite number of times and we
2877                  * can survive intermittent errors.
2878                  */
2879                 buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2880                 /* LOGICAL UNIT COMMUNICATION FAILURE */
2881                 buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2882                 break;
2883         }
2884         /*
2885          * This code uses linux/include/scsi/scsi.h SAM status codes!
2886          */
2887         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2888         /*
2889          * Automatically padded, this value is encoded in the fabric's
2890          * data_length response PDU containing the SCSI defined sense data.
2891          */
2892         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2893
2894 after_reason:
2895         trace_target_cmd_complete(cmd);
2896         return cmd->se_tfo->queue_status(cmd);
2897 }
2898 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2899
2900 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2901 {
2902         if (!(cmd->transport_state & CMD_T_ABORTED))
2903                 return 0;
2904
2905         /*
2906          * If cmd has been aborted but either no status is to be sent or it has
2907          * already been sent, just return
2908          */
2909         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
2910                 return 1;
2911
2912         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08llx\n",
2913                  cmd->t_task_cdb[0], cmd->tag);
2914
2915         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2916         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2917         trace_target_cmd_complete(cmd);
2918         cmd->se_tfo->queue_status(cmd);
2919
2920         return 1;
2921 }
2922 EXPORT_SYMBOL(transport_check_aborted_status);
2923
2924 void transport_send_task_abort(struct se_cmd *cmd)
2925 {
2926         unsigned long flags;
2927
2928         spin_lock_irqsave(&cmd->t_state_lock, flags);
2929         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
2930                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2931                 return;
2932         }
2933         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2934
2935         /*
2936          * If there are still expected incoming fabric WRITEs, we wait
2937          * until until they have completed before sending a TASK_ABORTED
2938          * response.  This response with TASK_ABORTED status will be
2939          * queued back to fabric module by transport_check_aborted_status().
2940          */
2941         if (cmd->data_direction == DMA_TO_DEVICE) {
2942                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2943                         cmd->transport_state |= CMD_T_ABORTED;
2944                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
2945                         return;
2946                 }
2947         }
2948         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2949
2950         transport_lun_remove_cmd(cmd);
2951
2952         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
2953                  cmd->t_task_cdb[0], cmd->tag);
2954
2955         trace_target_cmd_complete(cmd);
2956         cmd->se_tfo->queue_status(cmd);
2957 }
2958
2959 static void target_tmr_work(struct work_struct *work)
2960 {
2961         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2962         struct se_device *dev = cmd->se_dev;
2963         struct se_tmr_req *tmr = cmd->se_tmr_req;
2964         int ret;
2965
2966         switch (tmr->function) {
2967         case TMR_ABORT_TASK:
2968                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
2969                 break;
2970         case TMR_ABORT_TASK_SET:
2971         case TMR_CLEAR_ACA:
2972         case TMR_CLEAR_TASK_SET:
2973                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2974                 break;
2975         case TMR_LUN_RESET:
2976                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2977                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2978                                          TMR_FUNCTION_REJECTED;
2979                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
2980                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
2981                                                cmd->orig_fe_lun, 0x29,
2982                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
2983                 }
2984                 break;
2985         case TMR_TARGET_WARM_RESET:
2986                 tmr->response = TMR_FUNCTION_REJECTED;
2987                 break;
2988         case TMR_TARGET_COLD_RESET:
2989                 tmr->response = TMR_FUNCTION_REJECTED;
2990                 break;
2991         default:
2992                 pr_err("Uknown TMR function: 0x%02x.\n",
2993                                 tmr->function);
2994                 tmr->response = TMR_FUNCTION_REJECTED;
2995                 break;
2996         }
2997
2998         cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2999         cmd->se_tfo->queue_tm_rsp(cmd);
3000
3001         transport_cmd_check_stop_to_fabric(cmd);
3002 }
3003
3004 int transport_generic_handle_tmr(
3005         struct se_cmd *cmd)
3006 {
3007         unsigned long flags;
3008
3009         spin_lock_irqsave(&cmd->t_state_lock, flags);
3010         cmd->transport_state |= CMD_T_ACTIVE;
3011         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3012
3013         INIT_WORK(&cmd->work, target_tmr_work);
3014         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3015         return 0;
3016 }
3017 EXPORT_SYMBOL(transport_generic_handle_tmr);
3018
3019 bool
3020 target_check_wce(struct se_device *dev)
3021 {
3022         bool wce = false;
3023
3024         if (dev->transport->get_write_cache)
3025                 wce = dev->transport->get_write_cache(dev);
3026         else if (dev->dev_attrib.emulate_write_cache > 0)
3027                 wce = true;
3028
3029         return wce;
3030 }
3031
3032 bool
3033 target_check_fua(struct se_device *dev)
3034 {
3035         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3036 }