drivers/target/target_core_transport.c

   1 /*******************************************************************************
   2  * Filename:  target_core_transport.c
   3  *
   4  * This file contains the Generic Target Engine Core.
   5  *
   6  * (c) Copyright 2002-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/net.h>
  27 #include <linux/delay.h>
  28 #include <linux/string.h>
  29 #include <linux/timer.h>
  30 #include <linux/slab.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/kthread.h>
  33 #include <linux/in.h>
  34 #include <linux/cdrom.h>
  35 #include <linux/module.h>
  36 #include <linux/ratelimit.h>
  37 #include <linux/vmalloc.h>
  38 #include <asm/unaligned.h>
  39 #include <net/sock.h>
  40 #include <net/tcp.h>
  41 #include <scsi/scsi_proto.h>
  42 #include <scsi/scsi_common.h>
  43
  44 #include <target/target_core_base.h>
  45 #include <target/target_core_backend.h>
  46 #include <target/target_core_fabric.h>
  47
  48 #include "target_core_internal.h"
  49 #include "target_core_alua.h"
  50 #include "target_core_pr.h"
  51 #include "target_core_ua.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/target.h>
  55
  56 static struct workqueue_struct *target_completion_wq;
  57 static struct kmem_cache *se_sess_cache;
  58 struct kmem_cache *se_ua_cache;
  59 struct kmem_cache *t10_pr_reg_cache;
  60 struct kmem_cache *t10_alua_lu_gp_cache;
  61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  63 struct kmem_cache *t10_alua_lba_map_cache;
  64 struct kmem_cache *t10_alua_lba_map_mem_cache;
  65
  66 static void transport_complete_task_attr(struct se_cmd *cmd);
  67 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
  68 static void transport_handle_queue_full(struct se_cmd *cmd,
  69                 struct se_device *dev, int err, bool write_pending);
  70 static void target_complete_ok_work(struct work_struct *work);
  71
  72 int init_se_kmem_caches(void)
  73 {
  74         se_sess_cache = kmem_cache_create("se_sess_cache",
  75                         sizeof(struct se_session), __alignof__(struct se_session),
  76                         0, NULL);
  77         if (!se_sess_cache) {
  78                 pr_err("kmem_cache_create() for struct se_session"
  79                                 " failed\n");
  80                 goto out;
  81         }
  82         se_ua_cache = kmem_cache_create("se_ua_cache",
  83                         sizeof(struct se_ua), __alignof__(struct se_ua),
  84                         0, NULL);
  85         if (!se_ua_cache) {
  86                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  87                 goto out_free_sess_cache;
  88         }
  89         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  90                         sizeof(struct t10_pr_registration),
  91                         __alignof__(struct t10_pr_registration), 0, NULL);
  92         if (!t10_pr_reg_cache) {
  93                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  94                                 " failed\n");
  95                 goto out_free_ua_cache;
  96         }
  97         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  98                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  99                         0, NULL);
 100         if (!t10_alua_lu_gp_cache) {
 101                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 102                                 " failed\n");
 103                 goto out_free_pr_reg_cache;
 104         }
 105         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 106                         sizeof(struct t10_alua_lu_gp_member),
 107                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 108         if (!t10_alua_lu_gp_mem_cache) {
 109                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 110                                 "cache failed\n");
 111                 goto out_free_lu_gp_cache;
 112         }
 113         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 114                         sizeof(struct t10_alua_tg_pt_gp),
 115                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 116         if (!t10_alua_tg_pt_gp_cache) {
 117                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 118                                 "cache failed\n");
 119                 goto out_free_lu_gp_mem_cache;
 120         }
 121         t10_alua_lba_map_cache = kmem_cache_create(
 122                         "t10_alua_lba_map_cache",
 123                         sizeof(struct t10_alua_lba_map),
 124                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 125         if (!t10_alua_lba_map_cache) {
 126                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 127                                 "cache failed\n");
 128                 goto out_free_tg_pt_gp_cache;
 129         }
 130         t10_alua_lba_map_mem_cache = kmem_cache_create(
 131                         "t10_alua_lba_map_mem_cache",
 132                         sizeof(struct t10_alua_lba_map_member),
 133                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 134         if (!t10_alua_lba_map_mem_cache) {
 135                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 136                                 "cache failed\n");
 137                 goto out_free_lba_map_cache;
 138         }
 139
 140         target_completion_wq = alloc_workqueue("target_completion",
 141                                                WQ_MEM_RECLAIM, 0);
 142         if (!target_completion_wq)
 143                 goto out_free_lba_map_mem_cache;
 144
 145         return 0;
 146
 147 out_free_lba_map_mem_cache:
 148         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 149 out_free_lba_map_cache:
 150         kmem_cache_destroy(t10_alua_lba_map_cache);
 151 out_free_tg_pt_gp_cache:
 152         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 153 out_free_lu_gp_mem_cache:
 154         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 155 out_free_lu_gp_cache:
 156         kmem_cache_destroy(t10_alua_lu_gp_cache);
 157 out_free_pr_reg_cache:
 158         kmem_cache_destroy(t10_pr_reg_cache);
 159 out_free_ua_cache:
 160         kmem_cache_destroy(se_ua_cache);
 161 out_free_sess_cache:
 162         kmem_cache_destroy(se_sess_cache);
 163 out:
 164         return -ENOMEM;
 165 }
 166
 167 void release_se_kmem_caches(void)
 168 {
 169         destroy_workqueue(target_completion_wq);
 170         kmem_cache_destroy(se_sess_cache);
 171         kmem_cache_destroy(se_ua_cache);
 172         kmem_cache_destroy(t10_pr_reg_cache);
 173         kmem_cache_destroy(t10_alua_lu_gp_cache);
 174         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 175         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 176         kmem_cache_destroy(t10_alua_lba_map_cache);
 177         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 178 }
 179
 180 /* This code ensures unique mib indexes are handed out. */
 181 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 182 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 183
 184 /*
 185  * Allocate a new row index for the entry type specified
 186  */
 187 u32 scsi_get_new_index(scsi_index_t type)
 188 {
 189         u32 new_index;
 190
 191         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 192
 193         spin_lock(&scsi_mib_index_lock);
 194         new_index = ++scsi_mib_index[type];
 195         spin_unlock(&scsi_mib_index_lock);
 196
 197         return new_index;
 198 }
 199
 200 void transport_subsystem_check_init(void)
 201 {
 202         int ret;
 203         static int sub_api_initialized;
 204
 205         if (sub_api_initialized)
 206                 return;
 207
 208         ret = IS_ENABLED(CONFIG_TCM_IBLOCK) && request_module("target_core_iblock");
 209         if (ret != 0)
 210                 pr_err("Unable to load target_core_iblock\n");
 211
 212         ret = IS_ENABLED(CONFIG_TCM_FILEIO) && request_module("target_core_file");
 213         if (ret != 0)
 214                 pr_err("Unable to load target_core_file\n");
 215
 216         ret = IS_ENABLED(CONFIG_TCM_PSCSI) && request_module("target_core_pscsi");
 217         if (ret != 0)
 218                 pr_err("Unable to load target_core_pscsi\n");
 219
 220         ret = IS_ENABLED(CONFIG_TCM_USER2) && request_module("target_core_user");
 221         if (ret != 0)
 222                 pr_err("Unable to load target_core_user\n");
 223
 224         sub_api_initialized = 1;
 225 }
 226
 227 static void target_release_sess_cmd_refcnt(struct percpu_ref *ref)
 228 {
 229         struct se_session *sess = container_of(ref, typeof(*sess), cmd_count);
 230
 231         wake_up(&sess->cmd_list_wq);
 232 }
 233
 234 /**
 235  * transport_init_session - initialize a session object
 236  * @se_sess: Session object pointer.
 237  *
 238  * The caller must have zero-initialized @se_sess before calling this function.
 239  */
 240 int transport_init_session(struct se_session *se_sess)
 241 {
 242         INIT_LIST_HEAD(&se_sess->sess_list);
 243         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 244         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 245         spin_lock_init(&se_sess->sess_cmd_lock);
 246         init_waitqueue_head(&se_sess->cmd_list_wq);
 247         return percpu_ref_init(&se_sess->cmd_count,
 248                                target_release_sess_cmd_refcnt, 0, GFP_KERNEL);
 249 }
 250 EXPORT_SYMBOL(transport_init_session);
 251
 252 /**
 253  * transport_alloc_session - allocate a session object and initialize it
 254  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
 255  */
 256 struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
 257 {
 258         struct se_session *se_sess;
 259         int ret;
 260
 261         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 262         if (!se_sess) {
 263                 pr_err("Unable to allocate struct se_session from"
 264                                 " se_sess_cache\n");
 265                 return ERR_PTR(-ENOMEM);
 266         }
 267         ret = transport_init_session(se_sess);
 268         if (ret < 0) {
 269                 kmem_cache_free(se_sess_cache, se_sess);
 270                 return ERR_PTR(ret);
 271         }
 272         se_sess->sup_prot_ops = sup_prot_ops;
 273
 274         return se_sess;
 275 }
 276 EXPORT_SYMBOL(transport_alloc_session);
 277
 278 /**
 279  * transport_alloc_session_tags - allocate target driver private data
 280  * @se_sess:  Session pointer.
 281  * @tag_num:  Maximum number of in-flight commands between initiator and target.
 282  * @tag_size: Size in bytes of the private data a target driver associates with
 283  *            each command.
 284  */
 285 int transport_alloc_session_tags(struct se_session *se_sess,
 286                                  unsigned int tag_num, unsigned int tag_size)
 287 {
 288         int rc;
 289
 290         se_sess->sess_cmd_map = kvcalloc(tag_size, tag_num,
 291                                          GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 292         if (!se_sess->sess_cmd_map) {
 293                 pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 294                 return -ENOMEM;
 295         }
 296
 297         rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
 298                         false, GFP_KERNEL, NUMA_NO_NODE);
 299         if (rc < 0) {
 300                 pr_err("Unable to init se_sess->sess_tag_pool,"
 301                         " tag_num: %u\n", tag_num);
 302                 kvfree(se_sess->sess_cmd_map);
 303                 se_sess->sess_cmd_map = NULL;
 304                 return -ENOMEM;
 305         }
 306
 307         return 0;
 308 }
 309 EXPORT_SYMBOL(transport_alloc_session_tags);
 310
 311 /**
 312  * transport_init_session_tags - allocate a session and target driver private data
 313  * @tag_num:  Maximum number of in-flight commands between initiator and target.
 314  * @tag_size: Size in bytes of the private data a target driver associates with
 315  *            each command.
 316  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
 317  */
 318 static struct se_session *
 319 transport_init_session_tags(unsigned int tag_num, unsigned int tag_size,
 320                             enum target_prot_op sup_prot_ops)
 321 {
 322         struct se_session *se_sess;
 323         int rc;
 324
 325         if (tag_num != 0 && !tag_size) {
 326                 pr_err("init_session_tags called with percpu-ida tag_num:"
 327                        " %u, but zero tag_size\n", tag_num);
 328                 return ERR_PTR(-EINVAL);
 329         }
 330         if (!tag_num && tag_size) {
 331                 pr_err("init_session_tags called with percpu-ida tag_size:"
 332                        " %u, but zero tag_num\n", tag_size);
 333                 return ERR_PTR(-EINVAL);
 334         }
 335
 336         se_sess = transport_alloc_session(sup_prot_ops);
 337         if (IS_ERR(se_sess))
 338                 return se_sess;
 339
 340         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 341         if (rc < 0) {
 342                 transport_free_session(se_sess);
 343                 return ERR_PTR(-ENOMEM);
 344         }
 345
 346         return se_sess;
 347 }
 348
 349 /*
 350  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 351  */
 352 void __transport_register_session(
 353         struct se_portal_group *se_tpg,
 354         struct se_node_acl *se_nacl,
 355         struct se_session *se_sess,
 356         void *fabric_sess_ptr)
 357 {
 358         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 359         unsigned char buf[PR_REG_ISID_LEN];
 360         unsigned long flags;
 361
 362         se_sess->se_tpg = se_tpg;
 363         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 364         /*
 365          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 366          *
 367          * Only set for struct se_session's that will actually be moving I/O.
 368          * eg: *NOT* discovery sessions.
 369          */
 370         if (se_nacl) {
 371                 /*
 372                  *
 373                  * Determine if fabric allows for T10-PI feature bits exposed to
 374                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 375                  *
 376                  * If so, then always save prot_type on a per se_node_acl node
 377                  * basis and re-instate the previous sess_prot_type to avoid
 378                  * disabling PI from below any previously initiator side
 379                  * registered LUNs.
 380                  */
 381                 if (se_nacl->saved_prot_type)
 382                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 383                 else if (tfo->tpg_check_prot_fabric_only)
 384                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 385                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 386                 /*
 387                  * If the fabric module supports an ISID based TransportID,
 388                  * save this value in binary from the fabric I_T Nexus now.
 389                  */
 390                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 391                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 392                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 393                                         &buf[0], PR_REG_ISID_LEN);
 394                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 395                 }
 396
 397                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 398                 /*
 399                  * The se_nacl->nacl_sess pointer will be set to the
 400                  * last active I_T Nexus for each struct se_node_acl.
 401                  */
 402                 se_nacl->nacl_sess = se_sess;
 403
 404                 list_add_tail(&se_sess->sess_acl_list,
 405                               &se_nacl->acl_sess_list);
 406                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 407         }
 408         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 409
 410         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 411                 se_tpg->se_tpg_tfo->fabric_name, se_sess->fabric_sess_ptr);
 412 }
 413 EXPORT_SYMBOL(__transport_register_session);
 414
 415 void transport_register_session(
 416         struct se_portal_group *se_tpg,
 417         struct se_node_acl *se_nacl,
 418         struct se_session *se_sess,
 419         void *fabric_sess_ptr)
 420 {
 421         unsigned long flags;
 422
 423         spin_lock_irqsave(&se_tpg->session_lock, flags);
 424         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 425         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 426 }
 427 EXPORT_SYMBOL(transport_register_session);
 428
 429 struct se_session *
 430 target_setup_session(struct se_portal_group *tpg,
 431                      unsigned int tag_num, unsigned int tag_size,
 432                      enum target_prot_op prot_op,
 433                      const char *initiatorname, void *private,
 434                      int (*callback)(struct se_portal_group *,
 435                                      struct se_session *, void *))
 436 {
 437         struct se_session *sess;
 438
 439         /*
 440          * If the fabric driver is using percpu-ida based pre allocation
 441          * of I/O descriptor tags, go ahead and perform that setup now..
 442          */
 443         if (tag_num != 0)
 444                 sess = transport_init_session_tags(tag_num, tag_size, prot_op);
 445         else
 446                 sess = transport_alloc_session(prot_op);
 447
 448         if (IS_ERR(sess))
 449                 return sess;
 450
 451         sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
 452                                         (unsigned char *)initiatorname);
 453         if (!sess->se_node_acl) {
 454                 transport_free_session(sess);
 455                 return ERR_PTR(-EACCES);
 456         }
 457         /*
 458          * Go ahead and perform any remaining fabric setup that is
 459          * required before transport_register_session().
 460          */
 461         if (callback != NULL) {
 462                 int rc = callback(tpg, sess, private);
 463                 if (rc) {
 464                         transport_free_session(sess);
 465                         return ERR_PTR(rc);
 466                 }
 467         }
 468
 469         transport_register_session(tpg, sess->se_node_acl, sess, private);
 470         return sess;
 471 }
 472 EXPORT_SYMBOL(target_setup_session);
 473
 474 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 475 {
 476         struct se_session *se_sess;
 477         ssize_t len = 0;
 478
 479         spin_lock_bh(&se_tpg->session_lock);
 480         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 481                 if (!se_sess->se_node_acl)
 482                         continue;
 483                 if (!se_sess->se_node_acl->dynamic_node_acl)
 484                         continue;
 485                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 486                         break;
 487
 488                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 489                                 se_sess->se_node_acl->initiatorname);
 490                 len += 1; /* Include NULL terminator */
 491         }
 492         spin_unlock_bh(&se_tpg->session_lock);
 493
 494         return len;
 495 }
 496 EXPORT_SYMBOL(target_show_dynamic_sessions);
 497
 498 static void target_complete_nacl(struct kref *kref)
 499 {
 500         struct se_node_acl *nacl = container_of(kref,
 501                                 struct se_node_acl, acl_kref);
 502         struct se_portal_group *se_tpg = nacl->se_tpg;
 503
 504         if (!nacl->dynamic_stop) {
 505                 complete(&nacl->acl_free_comp);
 506                 return;
 507         }
 508
 509         mutex_lock(&se_tpg->acl_node_mutex);
 510         list_del_init(&nacl->acl_list);
 511         mutex_unlock(&se_tpg->acl_node_mutex);
 512
 513         core_tpg_wait_for_nacl_pr_ref(nacl);
 514         core_free_device_list_for_node(nacl, se_tpg);
 515         kfree(nacl);
 516 }
 517
 518 void target_put_nacl(struct se_node_acl *nacl)
 519 {
 520         kref_put(&nacl->acl_kref, target_complete_nacl);
 521 }
 522 EXPORT_SYMBOL(target_put_nacl);
 523
 524 void transport_deregister_session_configfs(struct se_session *se_sess)
 525 {
 526         struct se_node_acl *se_nacl;
 527         unsigned long flags;
 528         /*
 529          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 530          */
 531         se_nacl = se_sess->se_node_acl;
 532         if (se_nacl) {
 533                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 534                 if (!list_empty(&se_sess->sess_acl_list))
 535                         list_del_init(&se_sess->sess_acl_list);
 536                 /*
 537                  * If the session list is empty, then clear the pointer.
 538                  * Otherwise, set the struct se_session pointer from the tail
 539                  * element of the per struct se_node_acl active session list.
 540                  */
 541                 if (list_empty(&se_nacl->acl_sess_list))
 542                         se_nacl->nacl_sess = NULL;
 543                 else {
 544                         se_nacl->nacl_sess = container_of(
 545                                         se_nacl->acl_sess_list.prev,
 546                                         struct se_session, sess_acl_list);
 547                 }
 548                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 549         }
 550 }
 551 EXPORT_SYMBOL(transport_deregister_session_configfs);
 552
 553 void transport_free_session(struct se_session *se_sess)
 554 {
 555         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 556
 557         /*
 558          * Drop the se_node_acl->nacl_kref obtained from within
 559          * core_tpg_get_initiator_node_acl().
 560          */
 561         if (se_nacl) {
 562                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 563                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 564                 unsigned long flags;
 565
 566                 se_sess->se_node_acl = NULL;
 567
 568                 /*
 569                  * Also determine if we need to drop the extra ->cmd_kref if
 570                  * it had been previously dynamically generated, and
 571                  * the endpoint is not caching dynamic ACLs.
 572                  */
 573                 mutex_lock(&se_tpg->acl_node_mutex);
 574                 if (se_nacl->dynamic_node_acl &&
 575                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 576                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 577                         if (list_empty(&se_nacl->acl_sess_list))
 578                                 se_nacl->dynamic_stop = true;
 579                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 580
 581                         if (se_nacl->dynamic_stop)
 582                                 list_del_init(&se_nacl->acl_list);
 583                 }
 584                 mutex_unlock(&se_tpg->acl_node_mutex);
 585
 586                 if (se_nacl->dynamic_stop)
 587                         target_put_nacl(se_nacl);
 588
 589                 target_put_nacl(se_nacl);
 590         }
 591         if (se_sess->sess_cmd_map) {
 592                 sbitmap_queue_free(&se_sess->sess_tag_pool);
 593                 kvfree(se_sess->sess_cmd_map);
 594         }
 595         percpu_ref_exit(&se_sess->cmd_count);
 596         kmem_cache_free(se_sess_cache, se_sess);
 597 }
 598 EXPORT_SYMBOL(transport_free_session);
 599
 600 void transport_deregister_session(struct se_session *se_sess)
 601 {
 602         struct se_portal_group *se_tpg = se_sess->se_tpg;
 603         unsigned long flags;
 604
 605         if (!se_tpg) {
 606                 transport_free_session(se_sess);
 607                 return;
 608         }
 609
 610         spin_lock_irqsave(&se_tpg->session_lock, flags);
 611         list_del(&se_sess->sess_list);
 612         se_sess->se_tpg = NULL;
 613         se_sess->fabric_sess_ptr = NULL;
 614         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 615
 616         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 617                 se_tpg->se_tpg_tfo->fabric_name);
 618         /*
 619          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 620          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 621          * removal context from within transport_free_session() code.
 622          *
 623          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 624          * to release all remaining generate_node_acl=1 created ACL resources.
 625          */
 626
 627         transport_free_session(se_sess);
 628 }
 629 EXPORT_SYMBOL(transport_deregister_session);
 630
 631 void target_remove_session(struct se_session *se_sess)
 632 {
 633         transport_deregister_session_configfs(se_sess);
 634         transport_deregister_session(se_sess);
 635 }
 636 EXPORT_SYMBOL(target_remove_session);
 637
 638 static void target_remove_from_state_list(struct se_cmd *cmd)
 639 {
 640         struct se_device *dev = cmd->se_dev;
 641         unsigned long flags;
 642
 643         if (!dev)
 644                 return;
 645
 646         spin_lock_irqsave(&dev->execute_task_lock, flags);
 647         if (cmd->state_active) {
 648                 list_del(&cmd->state_list);
 649                 cmd->state_active = false;
 650         }
 651         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 652 }
 653
 654 /*
 655  * This function is called by the target core after the target core has
 656  * finished processing a SCSI command or SCSI TMF. Both the regular command
 657  * processing code and the code for aborting commands can call this
 658  * function. CMD_T_STOP is set if and only if another thread is waiting
 659  * inside transport_wait_for_tasks() for t_transport_stop_comp.
 660  */
 661 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 662 {
 663         unsigned long flags;
 664
 665         target_remove_from_state_list(cmd);
 666
 667         /*
 668          * Clear struct se_cmd->se_lun before the handoff to FE.
 669          */
 670         cmd->se_lun = NULL;
 671
 672         spin_lock_irqsave(&cmd->t_state_lock, flags);
 673         /*
 674          * Determine if frontend context caller is requesting the stopping of
 675          * this command for frontend exceptions.
 676          */
 677         if (cmd->transport_state & CMD_T_STOP) {
 678                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 679                         __func__, __LINE__, cmd->tag);
 680
 681                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 682
 683                 complete_all(&cmd->t_transport_stop_comp);
 684                 return 1;
 685         }
 686         cmd->transport_state &= ~CMD_T_ACTIVE;
 687         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 688
 689         /*
 690          * Some fabric modules like tcm_loop can release their internally
 691          * allocated I/O reference and struct se_cmd now.
 692          *
 693          * Fabric modules are expected to return '1' here if the se_cmd being
 694          * passed is released at this point, or zero if not being released.
 695          */
 696         return cmd->se_tfo->check_stop_free(cmd);
 697 }
 698
 699 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 700 {
 701         struct se_lun *lun = cmd->se_lun;
 702
 703         if (!lun)
 704                 return;
 705
 706         if (cmpxchg(&cmd->lun_ref_active, true, false))
 707                 percpu_ref_put(&lun->lun_ref);
 708 }
 709
 710 static void target_complete_failure_work(struct work_struct *work)
 711 {
 712         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 713
 714         transport_generic_request_failure(cmd,
 715                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 716 }
 717
 718 /*
 719  * Used when asking transport to copy Sense Data from the underlying
 720  * Linux/SCSI struct scsi_cmnd
 721  */
 722 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 723 {
 724         struct se_device *dev = cmd->se_dev;
 725
 726         WARN_ON(!cmd->se_lun);
 727
 728         if (!dev)
 729                 return NULL;
 730
 731         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 732                 return NULL;
 733
 734         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 735
 736         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 737                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 738         return cmd->sense_buffer;
 739 }
 740
 741 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
 742 {
 743         unsigned char *cmd_sense_buf;
 744         unsigned long flags;
 745
 746         spin_lock_irqsave(&cmd->t_state_lock, flags);
 747         cmd_sense_buf = transport_get_sense_buffer(cmd);
 748         if (!cmd_sense_buf) {
 749                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 750                 return;
 751         }
 752
 753         cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
 754         memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
 755         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 756 }
 757 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
 758
 759 static void target_handle_abort(struct se_cmd *cmd)
 760 {
 761         bool tas = cmd->transport_state & CMD_T_TAS;
 762         bool ack_kref = cmd->se_cmd_flags & SCF_ACK_KREF;
 763         int ret;
 764
 765         pr_debug("tag %#llx: send_abort_response = %d\n", cmd->tag, tas);
 766
 767         if (tas) {
 768                 if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
 769                         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
 770                         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
 771                                  cmd->t_task_cdb[0], cmd->tag);
 772                         trace_target_cmd_complete(cmd);
 773                         ret = cmd->se_tfo->queue_status(cmd);
 774                         if (ret) {
 775                                 transport_handle_queue_full(cmd, cmd->se_dev,
 776                                                             ret, false);
 777                                 return;
 778                         }
 779                 } else {
 780                         cmd->se_tmr_req->response = TMR_FUNCTION_REJECTED;
 781                         cmd->se_tfo->queue_tm_rsp(cmd);
 782                 }
 783         } else {
 784                 /*
 785                  * Allow the fabric driver to unmap any resources before
 786                  * releasing the descriptor via TFO->release_cmd().
 787                  */
 788                 cmd->se_tfo->aborted_task(cmd);
 789                 if (ack_kref)
 790                         WARN_ON_ONCE(target_put_sess_cmd(cmd) != 0);
 791                 /*
 792                  * To do: establish a unit attention condition on the I_T
 793                  * nexus associated with cmd. See also the paragraph "Aborting
 794                  * commands" in SAM.
 795                  */
 796         }
 797
 798         WARN_ON_ONCE(kref_read(&cmd->cmd_kref) == 0);
 799
 800         transport_lun_remove_cmd(cmd);
 801
 802         transport_cmd_check_stop_to_fabric(cmd);
 803 }
 804
 805 static void target_abort_work(struct work_struct *work)
 806 {
 807         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 808
 809         target_handle_abort(cmd);
 810 }
 811
 812 static bool target_cmd_interrupted(struct se_cmd *cmd)
 813 {
 814         int post_ret;
 815
 816         if (cmd->transport_state & CMD_T_ABORTED) {
 817                 if (cmd->transport_complete_callback)
 818                         cmd->transport_complete_callback(cmd, false, &post_ret);
 819                 INIT_WORK(&cmd->work, target_abort_work);
 820                 queue_work(target_completion_wq, &cmd->work);
 821                 return true;
 822         } else if (cmd->transport_state & CMD_T_STOP) {
 823                 if (cmd->transport_complete_callback)
 824                         cmd->transport_complete_callback(cmd, false, &post_ret);
 825                 complete_all(&cmd->t_transport_stop_comp);
 826                 return true;
 827         }
 828
 829         return false;
 830 }
 831
 832 /* May be called from interrupt context so must not sleep. */
 833 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 834 {
 835         int success;
 836         unsigned long flags;
 837
 838         if (target_cmd_interrupted(cmd))
 839                 return;
 840
 841         cmd->scsi_status = scsi_status;
 842
 843         spin_lock_irqsave(&cmd->t_state_lock, flags);
 844         switch (cmd->scsi_status) {
 845         case SAM_STAT_CHECK_CONDITION:
 846                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 847                         success = 1;
 848                 else
 849                         success = 0;
 850                 break;
 851         default:
 852                 success = 1;
 853                 break;
 854         }
 855
 856         cmd->t_state = TRANSPORT_COMPLETE;
 857         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 858         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 859
 860         INIT_WORK(&cmd->work, success ? target_complete_ok_work :
 861                   target_complete_failure_work);
 862         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 863                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 864         else
 865                 queue_work(target_completion_wq, &cmd->work);
 866 }
 867 EXPORT_SYMBOL(target_complete_cmd);
 868
 869 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 870 {
 871         if ((scsi_status == SAM_STAT_GOOD ||
 872              cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
 873             length < cmd->data_length) {
 874                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 875                         cmd->residual_count += cmd->data_length - length;
 876                 } else {
 877                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 878                         cmd->residual_count = cmd->data_length - length;
 879                 }
 880
 881                 cmd->data_length = length;
 882         }
 883
 884         target_complete_cmd(cmd, scsi_status);
 885 }
 886 EXPORT_SYMBOL(target_complete_cmd_with_length);
 887
 888 static void target_add_to_state_list(struct se_cmd *cmd)
 889 {
 890         struct se_device *dev = cmd->se_dev;
 891         unsigned long flags;
 892
 893         spin_lock_irqsave(&dev->execute_task_lock, flags);
 894         if (!cmd->state_active) {
 895                 list_add_tail(&cmd->state_list, &dev->state_list);
 896                 cmd->state_active = true;
 897         }
 898         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 899 }
 900
 901 /*
 902  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 903  */
 904 static void transport_write_pending_qf(struct se_cmd *cmd);
 905 static void transport_complete_qf(struct se_cmd *cmd);
 906
 907 void target_qf_do_work(struct work_struct *work)
 908 {
 909         struct se_device *dev = container_of(work, struct se_device,
 910                                         qf_work_queue);
 911         LIST_HEAD(qf_cmd_list);
 912         struct se_cmd *cmd, *cmd_tmp;
 913
 914         spin_lock_irq(&dev->qf_cmd_lock);
 915         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 916         spin_unlock_irq(&dev->qf_cmd_lock);
 917
 918         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 919                 list_del(&cmd->se_qf_node);
 920                 atomic_dec_mb(&dev->dev_qf_count);
 921
 922                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 923                         " context: %s\n", cmd->se_tfo->fabric_name, cmd,
 924                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 925                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 926                         : "UNKNOWN");
 927
 928                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 929                         transport_write_pending_qf(cmd);
 930                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 931                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 932                         transport_complete_qf(cmd);
 933         }
 934 }
 935
 936 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 937 {
 938         switch (cmd->data_direction) {
 939         case DMA_NONE:
 940                 return "NONE";
 941         case DMA_FROM_DEVICE:
 942                 return "READ";
 943         case DMA_TO_DEVICE:
 944                 return "WRITE";
 945         case DMA_BIDIRECTIONAL:
 946                 return "BIDI";
 947         default:
 948                 break;
 949         }
 950
 951         return "UNKNOWN";
 952 }
 953
 954 void transport_dump_dev_state(
 955         struct se_device *dev,
 956         char *b,
 957         int *bl)
 958 {
 959         *bl += sprintf(b + *bl, "Status: ");
 960         if (dev->export_count)
 961                 *bl += sprintf(b + *bl, "ACTIVATED");
 962         else
 963                 *bl += sprintf(b + *bl, "DEACTIVATED");
 964
 965         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 966         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 967                 dev->dev_attrib.block_size,
 968                 dev->dev_attrib.hw_max_sectors);
 969         *bl += sprintf(b + *bl, "        ");
 970 }
 971
 972 void transport_dump_vpd_proto_id(
 973         struct t10_vpd *vpd,
 974         unsigned char *p_buf,
 975         int p_buf_len)
 976 {
 977         unsigned char buf[VPD_TMP_BUF_SIZE];
 978         int len;
 979
 980         memset(buf, 0, VPD_TMP_BUF_SIZE);
 981         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 982
 983         switch (vpd->protocol_identifier) {
 984         case 0x00:
 985                 sprintf(buf+len, "Fibre Channel\n");
 986                 break;
 987         case 0x10:
 988                 sprintf(buf+len, "Parallel SCSI\n");
 989                 break;
 990         case 0x20:
 991                 sprintf(buf+len, "SSA\n");
 992                 break;
 993         case 0x30:
 994                 sprintf(buf+len, "IEEE 1394\n");
 995                 break;
 996         case 0x40:
 997                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 998                                 " Protocol\n");
 999                 break;
1000         case 0x50:
1001                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
1002                 break;
1003         case 0x60:
1004                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
1005                 break;
1006         case 0x70:
1007                 sprintf(buf+len, "Automation/Drive Interface Transport"
1008                                 " Protocol\n");
1009                 break;
1010         case 0x80:
1011                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
1012                 break;
1013         default:
1014                 sprintf(buf+len, "Unknown 0x%02x\n",
1015                                 vpd->protocol_identifier);
1016                 break;
1017         }
1018
1019         if (p_buf)
1020                 strncpy(p_buf, buf, p_buf_len);
1021         else
1022                 pr_debug("%s", buf);
1023 }
1024
1025 void
1026 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
1027 {
1028         /*
1029          * Check if the Protocol Identifier Valid (PIV) bit is set..
1030          *
1031          * from spc3r23.pdf section 7.5.1
1032          */
1033          if (page_83[1] & 0x80) {
1034                 vpd->protocol_identifier = (page_83[0] & 0xf0);
1035                 vpd->protocol_identifier_set = 1;
1036                 transport_dump_vpd_proto_id(vpd, NULL, 0);
1037         }
1038 }
1039 EXPORT_SYMBOL(transport_set_vpd_proto_id);
1040
1041 int transport_dump_vpd_assoc(
1042         struct t10_vpd *vpd,
1043         unsigned char *p_buf,
1044         int p_buf_len)
1045 {
1046         unsigned char buf[VPD_TMP_BUF_SIZE];
1047         int ret = 0;
1048         int len;
1049
1050         memset(buf, 0, VPD_TMP_BUF_SIZE);
1051         len = sprintf(buf, "T10 VPD Identifier Association: ");
1052
1053         switch (vpd->association) {
1054         case 0x00:
1055                 sprintf(buf+len, "addressed logical unit\n");
1056                 break;
1057         case 0x10:
1058                 sprintf(buf+len, "target port\n");
1059                 break;
1060         case 0x20:
1061                 sprintf(buf+len, "SCSI target device\n");
1062                 break;
1063         default:
1064                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
1065                 ret = -EINVAL;
1066                 break;
1067         }
1068
1069         if (p_buf)
1070                 strncpy(p_buf, buf, p_buf_len);
1071         else
1072                 pr_debug("%s", buf);
1073
1074         return ret;
1075 }
1076
1077 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
1078 {
1079         /*
1080          * The VPD identification association..
1081          *
1082          * from spc3r23.pdf Section 7.6.3.1 Table 297
1083          */
1084         vpd->association = (page_83[1] & 0x30);
1085         return transport_dump_vpd_assoc(vpd, NULL, 0);
1086 }
1087 EXPORT_SYMBOL(transport_set_vpd_assoc);
1088
1089 int transport_dump_vpd_ident_type(
1090         struct t10_vpd *vpd,
1091         unsigned char *p_buf,
1092         int p_buf_len)
1093 {
1094         unsigned char buf[VPD_TMP_BUF_SIZE];
1095         int ret = 0;
1096         int len;
1097
1098         memset(buf, 0, VPD_TMP_BUF_SIZE);
1099         len = sprintf(buf, "T10 VPD Identifier Type: ");
1100
1101         switch (vpd->device_identifier_type) {
1102         case 0x00:
1103                 sprintf(buf+len, "Vendor specific\n");
1104                 break;
1105         case 0x01:
1106                 sprintf(buf+len, "T10 Vendor ID based\n");
1107                 break;
1108         case 0x02:
1109                 sprintf(buf+len, "EUI-64 based\n");
1110                 break;
1111         case 0x03:
1112                 sprintf(buf+len, "NAA\n");
1113                 break;
1114         case 0x04:
1115                 sprintf(buf+len, "Relative target port identifier\n");
1116                 break;
1117         case 0x08:
1118                 sprintf(buf+len, "SCSI name string\n");
1119                 break;
1120         default:
1121                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1122                                 vpd->device_identifier_type);
1123                 ret = -EINVAL;
1124                 break;
1125         }
1126
1127         if (p_buf) {
1128                 if (p_buf_len < strlen(buf)+1)
1129                         return -EINVAL;
1130                 strncpy(p_buf, buf, p_buf_len);
1131         } else {
1132                 pr_debug("%s", buf);
1133         }
1134
1135         return ret;
1136 }
1137
1138 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1139 {
1140         /*
1141          * The VPD identifier type..
1142          *
1143          * from spc3r23.pdf Section 7.6.3.1 Table 298
1144          */
1145         vpd->device_identifier_type = (page_83[1] & 0x0f);
1146         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1147 }
1148 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1149
1150 int transport_dump_vpd_ident(
1151         struct t10_vpd *vpd,
1152         unsigned char *p_buf,
1153         int p_buf_len)
1154 {
1155         unsigned char buf[VPD_TMP_BUF_SIZE];
1156         int ret = 0;
1157
1158         memset(buf, 0, VPD_TMP_BUF_SIZE);
1159
1160         switch (vpd->device_identifier_code_set) {
1161         case 0x01: /* Binary */
1162                 snprintf(buf, sizeof(buf),
1163                         "T10 VPD Binary Device Identifier: %s\n",
1164                         &vpd->device_identifier[0]);
1165                 break;
1166         case 0x02: /* ASCII */
1167                 snprintf(buf, sizeof(buf),
1168                         "T10 VPD ASCII Device Identifier: %s\n",
1169                         &vpd->device_identifier[0]);
1170                 break;
1171         case 0x03: /* UTF-8 */
1172                 snprintf(buf, sizeof(buf),
1173                         "T10 VPD UTF-8 Device Identifier: %s\n",
1174                         &vpd->device_identifier[0]);
1175                 break;
1176         default:
1177                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1178                         " 0x%02x", vpd->device_identifier_code_set);
1179                 ret = -EINVAL;
1180                 break;
1181         }
1182
1183         if (p_buf)
1184                 strncpy(p_buf, buf, p_buf_len);
1185         else
1186                 pr_debug("%s", buf);
1187
1188         return ret;
1189 }
1190
1191 int
1192 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1193 {
1194         static const char hex_str[] = "0123456789abcdef";
1195         int j = 0, i = 4; /* offset to start of the identifier */
1196
1197         /*
1198          * The VPD Code Set (encoding)
1199          *
1200          * from spc3r23.pdf Section 7.6.3.1 Table 296
1201          */
1202         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1203         switch (vpd->device_identifier_code_set) {
1204         case 0x01: /* Binary */
1205                 vpd->device_identifier[j++] =
1206                                 hex_str[vpd->device_identifier_type];
1207                 while (i < (4 + page_83[3])) {
1208                         vpd->device_identifier[j++] =
1209                                 hex_str[(page_83[i] & 0xf0) >> 4];
1210                         vpd->device_identifier[j++] =
1211                                 hex_str[page_83[i] & 0x0f];
1212                         i++;
1213                 }
1214                 break;
1215         case 0x02: /* ASCII */
1216         case 0x03: /* UTF-8 */
1217                 while (i < (4 + page_83[3]))
1218                         vpd->device_identifier[j++] = page_83[i++];
1219                 break;
1220         default:
1221                 break;
1222         }
1223
1224         return transport_dump_vpd_ident(vpd, NULL, 0);
1225 }
1226 EXPORT_SYMBOL(transport_set_vpd_ident);
1227
1228 static sense_reason_t
1229 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1230                                unsigned int size)
1231 {
1232         u32 mtl;
1233
1234         if (!cmd->se_tfo->max_data_sg_nents)
1235                 return TCM_NO_SENSE;
1236         /*
1237          * Check if fabric enforced maximum SGL entries per I/O descriptor
1238          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1239          * residual_count and reduce original cmd->data_length to maximum
1240          * length based on single PAGE_SIZE entry scatter-lists.
1241          */
1242         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1243         if (cmd->data_length > mtl) {
1244                 /*
1245                  * If an existing CDB overflow is present, calculate new residual
1246                  * based on CDB size minus fabric maximum transfer length.
1247                  *
1248                  * If an existing CDB underflow is present, calculate new residual
1249                  * based on original cmd->data_length minus fabric maximum transfer
1250                  * length.
1251                  *
1252                  * Otherwise, set the underflow residual based on cmd->data_length
1253                  * minus fabric maximum transfer length.
1254                  */
1255                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1256                         cmd->residual_count = (size - mtl);
1257                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1258                         u32 orig_dl = size + cmd->residual_count;
1259                         cmd->residual_count = (orig_dl - mtl);
1260                 } else {
1261                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1262                         cmd->residual_count = (cmd->data_length - mtl);
1263                 }
1264                 cmd->data_length = mtl;
1265                 /*
1266                  * Reset sbc_check_prot() calculated protection payload
1267                  * length based upon the new smaller MTL.
1268                  */
1269                 if (cmd->prot_length) {
1270                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1271                         cmd->prot_length = dev->prot_length * sectors;
1272                 }
1273         }
1274         return TCM_NO_SENSE;
1275 }
1276
1277 sense_reason_t
1278 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1279 {
1280         struct se_device *dev = cmd->se_dev;
1281
1282         if (cmd->unknown_data_length) {
1283                 cmd->data_length = size;
1284         } else if (size != cmd->data_length) {
1285                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1286                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1287                         " 0x%02x\n", cmd->se_tfo->fabric_name,
1288                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1289
1290                 if (cmd->data_direction == DMA_TO_DEVICE) {
1291                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1292                                 pr_err_ratelimited("Rejecting underflow/overflow"
1293                                                    " for WRITE data CDB\n");
1294                                 return TCM_INVALID_CDB_FIELD;
1295                         }
1296                         /*
1297                          * Some fabric drivers like iscsi-target still expect to
1298                          * always reject overflow writes.  Reject this case until
1299                          * full fabric driver level support for overflow writes
1300                          * is introduced tree-wide.
1301                          */
1302                         if (size > cmd->data_length) {
1303                                 pr_err_ratelimited("Rejecting overflow for"
1304                                                    " WRITE control CDB\n");
1305                                 return TCM_INVALID_CDB_FIELD;
1306                         }
1307                 }
1308                 /*
1309                  * Reject READ_* or WRITE_* with overflow/underflow for
1310                  * type SCF_SCSI_DATA_CDB.
1311                  */
1312                 if (dev->dev_attrib.block_size != 512)  {
1313                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1314                                 " CDB on non 512-byte sector setup subsystem"
1315                                 " plugin: %s\n", dev->transport->name);
1316                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1317                         return TCM_INVALID_CDB_FIELD;
1318                 }
1319                 /*
1320                  * For the overflow case keep the existing fabric provided
1321                  * ->data_length.  Otherwise for the underflow case, reset
1322                  * ->data_length to the smaller SCSI expected data transfer
1323                  * length.
1324                  */
1325                 if (size > cmd->data_length) {
1326                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1327                         cmd->residual_count = (size - cmd->data_length);
1328                 } else {
1329                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1330                         cmd->residual_count = (cmd->data_length - size);
1331                         cmd->data_length = size;
1332                 }
1333         }
1334
1335         return target_check_max_data_sg_nents(cmd, dev, size);
1336
1337 }
1338
1339 /*
1340  * Used by fabric modules containing a local struct se_cmd within their
1341  * fabric dependent per I/O descriptor.
1342  *
1343  * Preserves the value of @cmd->tag.
1344  */
1345 void transport_init_se_cmd(
1346         struct se_cmd *cmd,
1347         const struct target_core_fabric_ops *tfo,
1348         struct se_session *se_sess,
1349         u32 data_length,
1350         int data_direction,
1351         int task_attr,
1352         unsigned char *sense_buffer)
1353 {
1354         INIT_LIST_HEAD(&cmd->se_delayed_node);
1355         INIT_LIST_HEAD(&cmd->se_qf_node);
1356         INIT_LIST_HEAD(&cmd->se_cmd_list);
1357         INIT_LIST_HEAD(&cmd->state_list);
1358         init_completion(&cmd->t_transport_stop_comp);
1359         cmd->free_compl = NULL;
1360         cmd->abrt_compl = NULL;
1361         spin_lock_init(&cmd->t_state_lock);
1362         INIT_WORK(&cmd->work, NULL);
1363         kref_init(&cmd->cmd_kref);
1364
1365         cmd->se_tfo = tfo;
1366         cmd->se_sess = se_sess;
1367         cmd->data_length = data_length;
1368         cmd->data_direction = data_direction;
1369         cmd->sam_task_attr = task_attr;
1370         cmd->sense_buffer = sense_buffer;
1371
1372         cmd->state_active = false;
1373 }
1374 EXPORT_SYMBOL(transport_init_se_cmd);
1375
1376 static sense_reason_t
1377 transport_check_alloc_task_attr(struct se_cmd *cmd)
1378 {
1379         struct se_device *dev = cmd->se_dev;
1380
1381         /*
1382          * Check if SAM Task Attribute emulation is enabled for this
1383          * struct se_device storage object
1384          */
1385         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1386                 return 0;
1387
1388         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1389                 pr_debug("SAM Task Attribute ACA"
1390                         " emulation is not supported\n");
1391                 return TCM_INVALID_CDB_FIELD;
1392         }
1393
1394         return 0;
1395 }
1396
1397 sense_reason_t
1398 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1399 {
1400         struct se_device *dev = cmd->se_dev;
1401         sense_reason_t ret;
1402
1403         /*
1404          * Ensure that the received CDB is less than the max (252 + 8) bytes
1405          * for VARIABLE_LENGTH_CMD
1406          */
1407         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1408                 pr_err("Received SCSI CDB with command_size: %d that"
1409                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1410                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1411                 return TCM_INVALID_CDB_FIELD;
1412         }
1413         /*
1414          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1415          * allocate the additional extended CDB buffer now..  Otherwise
1416          * setup the pointer from __t_task_cdb to t_task_cdb.
1417          */
1418         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1419                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1420                                                 GFP_KERNEL);
1421                 if (!cmd->t_task_cdb) {
1422                         pr_err("Unable to allocate cmd->t_task_cdb"
1423                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1424                                 scsi_command_size(cdb),
1425                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1426                         return TCM_OUT_OF_RESOURCES;
1427                 }
1428         } else
1429                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1430         /*
1431          * Copy the original CDB into cmd->
1432          */
1433         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1434
1435         trace_target_sequencer_start(cmd);
1436
1437         ret = dev->transport->parse_cdb(cmd);
1438         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1439                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1440                                     cmd->se_tfo->fabric_name,
1441                                     cmd->se_sess->se_node_acl->initiatorname,
1442                                     cmd->t_task_cdb[0]);
1443         if (ret)
1444                 return ret;
1445
1446         ret = transport_check_alloc_task_attr(cmd);
1447         if (ret)
1448                 return ret;
1449
1450         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1451         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1452         return 0;
1453 }
1454 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1455
1456 /*
1457  * Used by fabric module frontends to queue tasks directly.
1458  * May only be used from process context.
1459  */
1460 int transport_handle_cdb_direct(
1461         struct se_cmd *cmd)
1462 {
1463         sense_reason_t ret;
1464
1465         if (!cmd->se_lun) {
1466                 dump_stack();
1467                 pr_err("cmd->se_lun is NULL\n");
1468                 return -EINVAL;
1469         }
1470         if (in_interrupt()) {
1471                 dump_stack();
1472                 pr_err("transport_generic_handle_cdb cannot be called"
1473                                 " from interrupt context\n");
1474                 return -EINVAL;
1475         }
1476         /*
1477          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1478          * outstanding descriptors are handled correctly during shutdown via
1479          * transport_wait_for_tasks()
1480          *
1481          * Also, we don't take cmd->t_state_lock here as we only expect
1482          * this to be called for initial descriptor submission.
1483          */
1484         cmd->t_state = TRANSPORT_NEW_CMD;
1485         cmd->transport_state |= CMD_T_ACTIVE;
1486
1487         /*
1488          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1489          * so follow TRANSPORT_NEW_CMD processing thread context usage
1490          * and call transport_generic_request_failure() if necessary..
1491          */
1492         ret = transport_generic_new_cmd(cmd);
1493         if (ret)
1494                 transport_generic_request_failure(cmd, ret);
1495         return 0;
1496 }
1497 EXPORT_SYMBOL(transport_handle_cdb_direct);
1498
1499 sense_reason_t
1500 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1501                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1502 {
1503         if (!sgl || !sgl_count)
1504                 return 0;
1505
1506         /*
1507          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1508          * scatterlists already have been set to follow what the fabric
1509          * passes for the original expected data transfer length.
1510          */
1511         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1512                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1513                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1514                 return TCM_INVALID_CDB_FIELD;
1515         }
1516
1517         cmd->t_data_sg = sgl;
1518         cmd->t_data_nents = sgl_count;
1519         cmd->t_bidi_data_sg = sgl_bidi;
1520         cmd->t_bidi_data_nents = sgl_bidi_count;
1521
1522         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1523         return 0;
1524 }
1525
1526 /**
1527  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1528  *                       se_cmd + use pre-allocated SGL memory.
1529  *
1530  * @se_cmd: command descriptor to submit
1531  * @se_sess: associated se_sess for endpoint
1532  * @cdb: pointer to SCSI CDB
1533  * @sense: pointer to SCSI sense buffer
1534  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1535  * @data_length: fabric expected data transfer length
1536  * @task_attr: SAM task attribute
1537  * @data_dir: DMA data direction
1538  * @flags: flags for command submission from target_sc_flags_tables
1539  * @sgl: struct scatterlist memory for unidirectional mapping
1540  * @sgl_count: scatterlist count for unidirectional mapping
1541  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1542  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1543  * @sgl_prot: struct scatterlist memory protection information
1544  * @sgl_prot_count: scatterlist count for protection information
1545  *
1546  * Task tags are supported if the caller has set @se_cmd->tag.
1547  *
1548  * Returns non zero to signal active I/O shutdown failure.  All other
1549  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1550  * but still return zero here.
1551  *
1552  * This may only be called from process context, and also currently
1553  * assumes internal allocation of fabric payload buffer by target-core.
1554  */
1555 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1556                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1557                 u32 data_length, int task_attr, int data_dir, int flags,
1558                 struct scatterlist *sgl, u32 sgl_count,
1559                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1560                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1561 {
1562         struct se_portal_group *se_tpg;
1563         sense_reason_t rc;
1564         int ret;
1565
1566         se_tpg = se_sess->se_tpg;
1567         BUG_ON(!se_tpg);
1568         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1569         BUG_ON(in_interrupt());
1570         /*
1571          * Initialize se_cmd for target operation.  From this point
1572          * exceptions are handled by sending exception status via
1573          * target_core_fabric_ops->queue_status() callback
1574          */
1575         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1576                                 data_length, data_dir, task_attr, sense);
1577
1578         if (flags & TARGET_SCF_USE_CPUID)
1579                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1580         else
1581                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1582
1583         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1584                 se_cmd->unknown_data_length = 1;
1585         /*
1586          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1587          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1588          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1589          * kref_put() to happen during fabric packet acknowledgement.
1590          */
1591         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1592         if (ret)
1593                 return ret;
1594         /*
1595          * Signal bidirectional data payloads to target-core
1596          */
1597         if (flags & TARGET_SCF_BIDI_OP)
1598                 se_cmd->se_cmd_flags |= SCF_BIDI;
1599         /*
1600          * Locate se_lun pointer and attach it to struct se_cmd
1601          */
1602         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1603         if (rc) {
1604                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1605                 target_put_sess_cmd(se_cmd);
1606                 return 0;
1607         }
1608
1609         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1610         if (rc != 0) {
1611                 transport_generic_request_failure(se_cmd, rc);
1612                 return 0;
1613         }
1614
1615         /*
1616          * Save pointers for SGLs containing protection information,
1617          * if present.
1618          */
1619         if (sgl_prot_count) {
1620                 se_cmd->t_prot_sg = sgl_prot;
1621                 se_cmd->t_prot_nents = sgl_prot_count;
1622                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1623         }
1624
1625         /*
1626          * When a non zero sgl_count has been passed perform SGL passthrough
1627          * mapping for pre-allocated fabric memory instead of having target
1628          * core perform an internal SGL allocation..
1629          */
1630         if (sgl_count != 0) {
1631                 BUG_ON(!sgl);
1632
1633                 /*
1634                  * A work-around for tcm_loop as some userspace code via
1635                  * scsi-generic do not memset their associated read buffers,
1636                  * so go ahead and do that here for type non-data CDBs.  Also
1637                  * note that this is currently guaranteed to be a single SGL
1638                  * for this case by target core in target_setup_cmd_from_cdb()
1639                  * -> transport_generic_cmd_sequencer().
1640                  */
1641                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1642                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1643                         unsigned char *buf = NULL;
1644
1645                         if (sgl)
1646                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1647
1648                         if (buf) {
1649                                 memset(buf, 0, sgl->length);
1650                                 kunmap(sg_page(sgl));
1651                         }
1652                 }
1653
1654                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1655                                 sgl_bidi, sgl_bidi_count);
1656                 if (rc != 0) {
1657                         transport_generic_request_failure(se_cmd, rc);
1658                         return 0;
1659                 }
1660         }
1661
1662         /*
1663          * Check if we need to delay processing because of ALUA
1664          * Active/NonOptimized primary access state..
1665          */
1666         core_alua_check_nonop_delay(se_cmd);
1667
1668         transport_handle_cdb_direct(se_cmd);
1669         return 0;
1670 }
1671 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1672
1673 /**
1674  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1675  *
1676  * @se_cmd: command descriptor to submit
1677  * @se_sess: associated se_sess for endpoint
1678  * @cdb: pointer to SCSI CDB
1679  * @sense: pointer to SCSI sense buffer
1680  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1681  * @data_length: fabric expected data transfer length
1682  * @task_attr: SAM task attribute
1683  * @data_dir: DMA data direction
1684  * @flags: flags for command submission from target_sc_flags_tables
1685  *
1686  * Task tags are supported if the caller has set @se_cmd->tag.
1687  *
1688  * Returns non zero to signal active I/O shutdown failure.  All other
1689  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1690  * but still return zero here.
1691  *
1692  * This may only be called from process context, and also currently
1693  * assumes internal allocation of fabric payload buffer by target-core.
1694  *
1695  * It also assumes interal target core SGL memory allocation.
1696  */
1697 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1698                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1699                 u32 data_length, int task_attr, int data_dir, int flags)
1700 {
1701         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1702                         unpacked_lun, data_length, task_attr, data_dir,
1703                         flags, NULL, 0, NULL, 0, NULL, 0);
1704 }
1705 EXPORT_SYMBOL(target_submit_cmd);
1706
1707 static void target_complete_tmr_failure(struct work_struct *work)
1708 {
1709         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1710
1711         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1712         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1713
1714         transport_lun_remove_cmd(se_cmd);
1715         transport_cmd_check_stop_to_fabric(se_cmd);
1716 }
1717
1718 static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
1719                                        u64 *unpacked_lun)
1720 {
1721         struct se_cmd *se_cmd;
1722         unsigned long flags;
1723         bool ret = false;
1724
1725         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
1726         list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
1727                 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1728                         continue;
1729
1730                 if (se_cmd->tag == tag) {
1731                         *unpacked_lun = se_cmd->orig_fe_lun;
1732                         ret = true;
1733                         break;
1734                 }
1735         }
1736         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
1737
1738         return ret;
1739 }
1740
1741 /**
1742  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1743  *                     for TMR CDBs
1744  *
1745  * @se_cmd: command descriptor to submit
1746  * @se_sess: associated se_sess for endpoint
1747  * @sense: pointer to SCSI sense buffer
1748  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1749  * @fabric_tmr_ptr: fabric context for TMR req
1750  * @tm_type: Type of TM request
1751  * @gfp: gfp type for caller
1752  * @tag: referenced task tag for TMR_ABORT_TASK
1753  * @flags: submit cmd flags
1754  *
1755  * Callable from all contexts.
1756  **/
1757
1758 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1759                 unsigned char *sense, u64 unpacked_lun,
1760                 void *fabric_tmr_ptr, unsigned char tm_type,
1761                 gfp_t gfp, u64 tag, int flags)
1762 {
1763         struct se_portal_group *se_tpg;
1764         int ret;
1765
1766         se_tpg = se_sess->se_tpg;
1767         BUG_ON(!se_tpg);
1768
1769         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1770                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1771         /*
1772          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1773          * allocation failure.
1774          */
1775         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1776         if (ret < 0)
1777                 return -ENOMEM;
1778
1779         if (tm_type == TMR_ABORT_TASK)
1780                 se_cmd->se_tmr_req->ref_task_tag = tag;
1781
1782         /* See target_submit_cmd for commentary */
1783         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1784         if (ret) {
1785                 core_tmr_release_req(se_cmd->se_tmr_req);
1786                 return ret;
1787         }
1788         /*
1789          * If this is ABORT_TASK with no explicit fabric provided LUN,
1790          * go ahead and search active session tags for a match to figure
1791          * out unpacked_lun for the original se_cmd.
1792          */
1793         if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
1794                 if (!target_lookup_lun_from_tag(se_sess, tag, &unpacked_lun))
1795                         goto failure;
1796         }
1797
1798         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1799         if (ret)
1800                 goto failure;
1801
1802         transport_generic_handle_tmr(se_cmd);
1803         return 0;
1804
1805         /*
1806          * For callback during failure handling, push this work off
1807          * to process context with TMR_LUN_DOES_NOT_EXIST status.
1808          */
1809 failure:
1810         INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1811         schedule_work(&se_cmd->work);
1812         return 0;
1813 }
1814 EXPORT_SYMBOL(target_submit_tmr);
1815
1816 /*
1817  * Handle SAM-esque emulation for generic transport request failures.
1818  */
1819 void transport_generic_request_failure(struct se_cmd *cmd,
1820                 sense_reason_t sense_reason)
1821 {
1822         int ret = 0, post_ret;
1823
1824         pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
1825                  sense_reason);
1826         target_show_cmd("-----[ ", cmd);
1827
1828         /*
1829          * For SAM Task Attribute emulation for failed struct se_cmd
1830          */
1831         transport_complete_task_attr(cmd);
1832
1833         if (cmd->transport_complete_callback)
1834                 cmd->transport_complete_callback(cmd, false, &post_ret);
1835
1836         if (cmd->transport_state & CMD_T_ABORTED) {
1837                 INIT_WORK(&cmd->work, target_abort_work);
1838                 queue_work(target_completion_wq, &cmd->work);
1839                 return;
1840         }
1841
1842         switch (sense_reason) {
1843         case TCM_NON_EXISTENT_LUN:
1844         case TCM_UNSUPPORTED_SCSI_OPCODE:
1845         case TCM_INVALID_CDB_FIELD:
1846         case TCM_INVALID_PARAMETER_LIST:
1847         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1848         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1849         case TCM_UNKNOWN_MODE_PAGE:
1850         case TCM_WRITE_PROTECTED:
1851         case TCM_ADDRESS_OUT_OF_RANGE:
1852         case TCM_CHECK_CONDITION_ABORT_CMD:
1853         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1854         case TCM_CHECK_CONDITION_NOT_READY:
1855         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1856         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1857         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1858         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1859         case TCM_TOO_MANY_TARGET_DESCS:
1860         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1861         case TCM_TOO_MANY_SEGMENT_DESCS:
1862         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1863                 break;
1864         case TCM_OUT_OF_RESOURCES:
1865                 cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
1866                 goto queue_status;
1867         case TCM_LUN_BUSY:
1868                 cmd->scsi_status = SAM_STAT_BUSY;
1869                 goto queue_status;
1870         case TCM_RESERVATION_CONFLICT:
1871                 /*
1872                  * No SENSE Data payload for this case, set SCSI Status
1873                  * and queue the response to $FABRIC_MOD.
1874                  *
1875                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1876                  */
1877                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1878                 /*
1879                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1880                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1881                  * CONFLICT STATUS.
1882                  *
1883                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1884                  */
1885                 if (cmd->se_sess &&
1886                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1887                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1888                                                cmd->orig_fe_lun, 0x2C,
1889                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1890                 }
1891
1892                 goto queue_status;
1893         default:
1894                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1895                         cmd->t_task_cdb[0], sense_reason);
1896                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1897                 break;
1898         }
1899
1900         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1901         if (ret)
1902                 goto queue_full;
1903
1904 check_stop:
1905         transport_lun_remove_cmd(cmd);
1906         transport_cmd_check_stop_to_fabric(cmd);
1907         return;
1908
1909 queue_status:
1910         trace_target_cmd_complete(cmd);
1911         ret = cmd->se_tfo->queue_status(cmd);
1912         if (!ret)
1913                 goto check_stop;
1914 queue_full:
1915         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1916 }
1917 EXPORT_SYMBOL(transport_generic_request_failure);
1918
1919 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1920 {
1921         sense_reason_t ret;
1922
1923         if (!cmd->execute_cmd) {
1924                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1925                 goto err;
1926         }
1927         if (do_checks) {
1928                 /*
1929                  * Check for an existing UNIT ATTENTION condition after
1930                  * target_handle_task_attr() has done SAM task attr
1931                  * checking, and possibly have already defered execution
1932                  * out to target_restart_delayed_cmds() context.
1933                  */
1934                 ret = target_scsi3_ua_check(cmd);
1935                 if (ret)
1936                         goto err;
1937
1938                 ret = target_alua_state_check(cmd);
1939                 if (ret)
1940                         goto err;
1941
1942                 ret = target_check_reservation(cmd);
1943                 if (ret) {
1944                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1945                         goto err;
1946                 }
1947         }
1948
1949         ret = cmd->execute_cmd(cmd);
1950         if (!ret)
1951                 return;
1952 err:
1953         spin_lock_irq(&cmd->t_state_lock);
1954         cmd->transport_state &= ~CMD_T_SENT;
1955         spin_unlock_irq(&cmd->t_state_lock);
1956
1957         transport_generic_request_failure(cmd, ret);
1958 }
1959
1960 static int target_write_prot_action(struct se_cmd *cmd)
1961 {
1962         u32 sectors;
1963         /*
1964          * Perform WRITE_INSERT of PI using software emulation when backend
1965          * device has PI enabled, if the transport has not already generated
1966          * PI using hardware WRITE_INSERT offload.
1967          */
1968         switch (cmd->prot_op) {
1969         case TARGET_PROT_DOUT_INSERT:
1970                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1971                         sbc_dif_generate(cmd);
1972                 break;
1973         case TARGET_PROT_DOUT_STRIP:
1974                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1975                         break;
1976
1977                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1978                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1979                                              sectors, 0, cmd->t_prot_sg, 0);
1980                 if (unlikely(cmd->pi_err)) {
1981                         spin_lock_irq(&cmd->t_state_lock);
1982                         cmd->transport_state &= ~CMD_T_SENT;
1983                         spin_unlock_irq(&cmd->t_state_lock);
1984                         transport_generic_request_failure(cmd, cmd->pi_err);
1985                         return -1;
1986                 }
1987                 break;
1988         default:
1989                 break;
1990         }
1991
1992         return 0;
1993 }
1994
1995 static bool target_handle_task_attr(struct se_cmd *cmd)
1996 {
1997         struct se_device *dev = cmd->se_dev;
1998
1999         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2000                 return false;
2001
2002         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
2003
2004         /*
2005          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
2006          * to allow the passed struct se_cmd list of tasks to the front of the list.
2007          */
2008         switch (cmd->sam_task_attr) {
2009         case TCM_HEAD_TAG:
2010                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
2011                          cmd->t_task_cdb[0]);
2012                 return false;
2013         case TCM_ORDERED_TAG:
2014                 atomic_inc_mb(&dev->dev_ordered_sync);
2015
2016                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
2017                          cmd->t_task_cdb[0]);
2018
2019                 /*
2020                  * Execute an ORDERED command if no other older commands
2021                  * exist that need to be completed first.
2022                  */
2023                 if (!atomic_read(&dev->simple_cmds))
2024                         return false;
2025                 break;
2026         default:
2027                 /*
2028                  * For SIMPLE and UNTAGGED Task Attribute commands
2029                  */
2030                 atomic_inc_mb(&dev->simple_cmds);
2031                 break;
2032         }
2033
2034         if (atomic_read(&dev->dev_ordered_sync) == 0)
2035                 return false;
2036
2037         spin_lock(&dev->delayed_cmd_lock);
2038         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
2039         spin_unlock(&dev->delayed_cmd_lock);
2040
2041         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
2042                 cmd->t_task_cdb[0], cmd->sam_task_attr);
2043         return true;
2044 }
2045
2046 void target_execute_cmd(struct se_cmd *cmd)
2047 {
2048         /*
2049          * Determine if frontend context caller is requesting the stopping of
2050          * this command for frontend exceptions.
2051          *
2052          * If the received CDB has already been aborted stop processing it here.
2053          */
2054         if (target_cmd_interrupted(cmd))
2055                 return;
2056
2057         spin_lock_irq(&cmd->t_state_lock);
2058         cmd->t_state = TRANSPORT_PROCESSING;
2059         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
2060         spin_unlock_irq(&cmd->t_state_lock);
2061
2062         if (target_write_prot_action(cmd))
2063                 return;
2064
2065         if (target_handle_task_attr(cmd)) {
2066                 spin_lock_irq(&cmd->t_state_lock);
2067                 cmd->transport_state &= ~CMD_T_SENT;
2068                 spin_unlock_irq(&cmd->t_state_lock);
2069                 return;
2070         }
2071
2072         __target_execute_cmd(cmd, true);
2073 }
2074 EXPORT_SYMBOL(target_execute_cmd);
2075
2076 /*
2077  * Process all commands up to the last received ORDERED task attribute which
2078  * requires another blocking boundary
2079  */
2080 static void target_restart_delayed_cmds(struct se_device *dev)
2081 {
2082         for (;;) {
2083                 struct se_cmd *cmd;
2084
2085                 spin_lock(&dev->delayed_cmd_lock);
2086                 if (list_empty(&dev->delayed_cmd_list)) {
2087                         spin_unlock(&dev->delayed_cmd_lock);
2088                         break;
2089                 }
2090
2091                 cmd = list_entry(dev->delayed_cmd_list.next,
2092                                  struct se_cmd, se_delayed_node);
2093                 list_del(&cmd->se_delayed_node);
2094                 spin_unlock(&dev->delayed_cmd_lock);
2095
2096                 cmd->transport_state |= CMD_T_SENT;
2097
2098                 __target_execute_cmd(cmd, true);
2099
2100                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
2101                         break;
2102         }
2103 }
2104
2105 /*
2106  * Called from I/O completion to determine which dormant/delayed
2107  * and ordered cmds need to have their tasks added to the execution queue.
2108  */
2109 static void transport_complete_task_attr(struct se_cmd *cmd)
2110 {
2111         struct se_device *dev = cmd->se_dev;
2112
2113         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2114                 return;
2115
2116         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2117                 goto restart;
2118
2119         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2120                 atomic_dec_mb(&dev->simple_cmds);
2121                 dev->dev_cur_ordered_id++;
2122         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2123                 dev->dev_cur_ordered_id++;
2124                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2125                          dev->dev_cur_ordered_id);
2126         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2127                 atomic_dec_mb(&dev->dev_ordered_sync);
2128
2129                 dev->dev_cur_ordered_id++;
2130                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2131                          dev->dev_cur_ordered_id);
2132         }
2133         cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2134
2135 restart:
2136         target_restart_delayed_cmds(dev);
2137 }
2138
2139 static void transport_complete_qf(struct se_cmd *cmd)
2140 {
2141         int ret = 0;
2142
2143         transport_complete_task_attr(cmd);
2144         /*
2145          * If a fabric driver ->write_pending() or ->queue_data_in() callback
2146          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2147          * the same callbacks should not be retried.  Return CHECK_CONDITION
2148          * if a scsi_status is not already set.
2149          *
2150          * If a fabric driver ->queue_status() has returned non zero, always
2151          * keep retrying no matter what..
2152          */
2153         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2154                 if (cmd->scsi_status)
2155                         goto queue_status;
2156
2157                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2158                 goto queue_status;
2159         }
2160
2161         /*
2162          * Check if we need to send a sense buffer from
2163          * the struct se_cmd in question. We do NOT want
2164          * to take this path of the IO has been marked as
2165          * needing to be treated like a "normal read". This
2166          * is the case if it's a tape read, and either the
2167          * FM, EOM, or ILI bits are set, but there is no
2168          * sense data.
2169          */
2170         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2171             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2172                 goto queue_status;
2173
2174         switch (cmd->data_direction) {
2175         case DMA_FROM_DEVICE:
2176                 /* queue status if not treating this as a normal read */
2177                 if (cmd->scsi_status &&
2178                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2179                         goto queue_status;
2180
2181                 trace_target_cmd_complete(cmd);
2182                 ret = cmd->se_tfo->queue_data_in(cmd);
2183                 break;
2184         case DMA_TO_DEVICE:
2185                 if (cmd->se_cmd_flags & SCF_BIDI) {
2186                         ret = cmd->se_tfo->queue_data_in(cmd);
2187                         break;
2188                 }
2189                 /* fall through */
2190         case DMA_NONE:
2191 queue_status:
2192                 trace_target_cmd_complete(cmd);
2193                 ret = cmd->se_tfo->queue_status(cmd);
2194                 break;
2195         default:
2196                 break;
2197         }
2198
2199         if (ret < 0) {
2200                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2201                 return;
2202         }
2203         transport_lun_remove_cmd(cmd);
2204         transport_cmd_check_stop_to_fabric(cmd);
2205 }
2206
2207 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2208                                         int err, bool write_pending)
2209 {
2210         /*
2211          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2212          * ->queue_data_in() callbacks from new process context.
2213          *
2214          * Otherwise for other errors, transport_complete_qf() will send
2215          * CHECK_CONDITION via ->queue_status() instead of attempting to
2216          * retry associated fabric driver data-transfer callbacks.
2217          */
2218         if (err == -EAGAIN || err == -ENOMEM) {
2219                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2220                                                  TRANSPORT_COMPLETE_QF_OK;
2221         } else {
2222                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2223                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2224         }
2225
2226         spin_lock_irq(&dev->qf_cmd_lock);
2227         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2228         atomic_inc_mb(&dev->dev_qf_count);
2229         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2230
2231         schedule_work(&cmd->se_dev->qf_work_queue);
2232 }
2233
2234 static bool target_read_prot_action(struct se_cmd *cmd)
2235 {
2236         switch (cmd->prot_op) {
2237         case TARGET_PROT_DIN_STRIP:
2238                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2239                         u32 sectors = cmd->data_length >>
2240                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2241
2242                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2243                                                      sectors, 0, cmd->t_prot_sg,
2244                                                      0);
2245                         if (cmd->pi_err)
2246                                 return true;
2247                 }
2248                 break;
2249         case TARGET_PROT_DIN_INSERT:
2250                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2251                         break;
2252
2253                 sbc_dif_generate(cmd);
2254                 break;
2255         default:
2256                 break;
2257         }
2258
2259         return false;
2260 }
2261
2262 static void target_complete_ok_work(struct work_struct *work)
2263 {
2264         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2265         int ret;
2266
2267         /*
2268          * Check if we need to move delayed/dormant tasks from cmds on the
2269          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2270          * Attribute.
2271          */
2272         transport_complete_task_attr(cmd);
2273
2274         /*
2275          * Check to schedule QUEUE_FULL work, or execute an existing
2276          * cmd->transport_qf_callback()
2277          */
2278         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2279                 schedule_work(&cmd->se_dev->qf_work_queue);
2280
2281         /*
2282          * Check if we need to send a sense buffer from
2283          * the struct se_cmd in question. We do NOT want
2284          * to take this path of the IO has been marked as
2285          * needing to be treated like a "normal read". This
2286          * is the case if it's a tape read, and either the
2287          * FM, EOM, or ILI bits are set, but there is no
2288          * sense data.
2289          */
2290         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2291             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2292                 WARN_ON(!cmd->scsi_status);
2293                 ret = transport_send_check_condition_and_sense(
2294                                         cmd, 0, 1);
2295                 if (ret)
2296                         goto queue_full;
2297
2298                 transport_lun_remove_cmd(cmd);
2299                 transport_cmd_check_stop_to_fabric(cmd);
2300                 return;
2301         }
2302         /*
2303          * Check for a callback, used by amongst other things
2304          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2305          */
2306         if (cmd->transport_complete_callback) {
2307                 sense_reason_t rc;
2308                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2309                 bool zero_dl = !(cmd->data_length);
2310                 int post_ret = 0;
2311
2312                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2313                 if (!rc && !post_ret) {
2314                         if (caw && zero_dl)
2315                                 goto queue_rsp;
2316
2317                         return;
2318                 } else if (rc) {
2319                         ret = transport_send_check_condition_and_sense(cmd,
2320                                                 rc, 0);
2321                         if (ret)
2322                                 goto queue_full;
2323
2324                         transport_lun_remove_cmd(cmd);
2325                         transport_cmd_check_stop_to_fabric(cmd);
2326                         return;
2327                 }
2328         }
2329
2330 queue_rsp:
2331         switch (cmd->data_direction) {
2332         case DMA_FROM_DEVICE:
2333                 /*
2334                  * if this is a READ-type IO, but SCSI status
2335                  * is set, then skip returning data and just
2336                  * return the status -- unless this IO is marked
2337                  * as needing to be treated as a normal read,
2338                  * in which case we want to go ahead and return
2339                  * the data. This happens, for example, for tape
2340                  * reads with the FM, EOM, or ILI bits set, with
2341                  * no sense data.
2342                  */
2343                 if (cmd->scsi_status &&
2344                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2345                         goto queue_status;
2346
2347                 atomic_long_add(cmd->data_length,
2348                                 &cmd->se_lun->lun_stats.tx_data_octets);
2349                 /*
2350                  * Perform READ_STRIP of PI using software emulation when
2351                  * backend had PI enabled, if the transport will not be
2352                  * performing hardware READ_STRIP offload.
2353                  */
2354                 if (target_read_prot_action(cmd)) {
2355                         ret = transport_send_check_condition_and_sense(cmd,
2356                                                 cmd->pi_err, 0);
2357                         if (ret)
2358                                 goto queue_full;
2359
2360                         transport_lun_remove_cmd(cmd);
2361                         transport_cmd_check_stop_to_fabric(cmd);
2362                         return;
2363                 }
2364
2365                 trace_target_cmd_complete(cmd);
2366                 ret = cmd->se_tfo->queue_data_in(cmd);
2367                 if (ret)
2368                         goto queue_full;
2369                 break;
2370         case DMA_TO_DEVICE:
2371                 atomic_long_add(cmd->data_length,
2372                                 &cmd->se_lun->lun_stats.rx_data_octets);
2373                 /*
2374                  * Check if we need to send READ payload for BIDI-COMMAND
2375                  */
2376                 if (cmd->se_cmd_flags & SCF_BIDI) {
2377                         atomic_long_add(cmd->data_length,
2378                                         &cmd->se_lun->lun_stats.tx_data_octets);
2379                         ret = cmd->se_tfo->queue_data_in(cmd);
2380                         if (ret)
2381                                 goto queue_full;
2382                         break;
2383                 }
2384                 /* fall through */
2385         case DMA_NONE:
2386 queue_status:
2387                 trace_target_cmd_complete(cmd);
2388                 ret = cmd->se_tfo->queue_status(cmd);
2389                 if (ret)
2390                         goto queue_full;
2391                 break;
2392         default:
2393                 break;
2394         }
2395
2396         transport_lun_remove_cmd(cmd);
2397         transport_cmd_check_stop_to_fabric(cmd);
2398         return;
2399
2400 queue_full:
2401         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2402                 " data_direction: %d\n", cmd, cmd->data_direction);
2403
2404         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2405 }
2406
2407 void target_free_sgl(struct scatterlist *sgl, int nents)
2408 {
2409         sgl_free_n_order(sgl, nents, 0);
2410 }
2411 EXPORT_SYMBOL(target_free_sgl);
2412
2413 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2414 {
2415         /*
2416          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2417          * emulation, and free + reset pointers if necessary..
2418          */
2419         if (!cmd->t_data_sg_orig)
2420                 return;
2421
2422         kfree(cmd->t_data_sg);
2423         cmd->t_data_sg = cmd->t_data_sg_orig;
2424         cmd->t_data_sg_orig = NULL;
2425         cmd->t_data_nents = cmd->t_data_nents_orig;
2426         cmd->t_data_nents_orig = 0;
2427 }
2428
2429 static inline void transport_free_pages(struct se_cmd *cmd)
2430 {
2431         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2432                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2433                 cmd->t_prot_sg = NULL;
2434                 cmd->t_prot_nents = 0;
2435         }
2436
2437         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2438                 /*
2439                  * Release special case READ buffer payload required for
2440                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2441                  */
2442                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2443                         target_free_sgl(cmd->t_bidi_data_sg,
2444                                            cmd->t_bidi_data_nents);
2445                         cmd->t_bidi_data_sg = NULL;
2446                         cmd->t_bidi_data_nents = 0;
2447                 }
2448                 transport_reset_sgl_orig(cmd);
2449                 return;
2450         }
2451         transport_reset_sgl_orig(cmd);
2452
2453         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2454         cmd->t_data_sg = NULL;
2455         cmd->t_data_nents = 0;
2456
2457         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2458         cmd->t_bidi_data_sg = NULL;
2459         cmd->t_bidi_data_nents = 0;
2460 }
2461
2462 void *transport_kmap_data_sg(struct se_cmd *cmd)
2463 {
2464         struct scatterlist *sg = cmd->t_data_sg;
2465         struct page **pages;
2466         int i;
2467
2468         /*
2469          * We need to take into account a possible offset here for fabrics like
2470          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2471          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2472          */
2473         if (!cmd->t_data_nents)
2474                 return NULL;
2475
2476         BUG_ON(!sg);
2477         if (cmd->t_data_nents == 1)
2478                 return kmap(sg_page(sg)) + sg->offset;
2479
2480         /* >1 page. use vmap */
2481         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2482         if (!pages)
2483                 return NULL;
2484
2485         /* convert sg[] to pages[] */
2486         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2487                 pages[i] = sg_page(sg);
2488         }
2489
2490         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2491         kfree(pages);
2492         if (!cmd->t_data_vmap)
2493                 return NULL;
2494
2495         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2496 }
2497 EXPORT_SYMBOL(transport_kmap_data_sg);
2498
2499 void transport_kunmap_data_sg(struct se_cmd *cmd)
2500 {
2501         if (!cmd->t_data_nents) {
2502                 return;
2503         } else if (cmd->t_data_nents == 1) {
2504                 kunmap(sg_page(cmd->t_data_sg));
2505                 return;
2506         }
2507
2508         vunmap(cmd->t_data_vmap);
2509         cmd->t_data_vmap = NULL;
2510 }
2511 EXPORT_SYMBOL(transport_kunmap_data_sg);
2512
2513 int
2514 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2515                  bool zero_page, bool chainable)
2516 {
2517         gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
2518
2519         *sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
2520         return *sgl ? 0 : -ENOMEM;
2521 }
2522 EXPORT_SYMBOL(target_alloc_sgl);
2523
2524 /*
2525  * Allocate any required resources to execute the command.  For writes we
2526  * might not have the payload yet, so notify the fabric via a call to
2527  * ->write_pending instead. Otherwise place it on the execution queue.
2528  */
2529 sense_reason_t
2530 transport_generic_new_cmd(struct se_cmd *cmd)
2531 {
2532         unsigned long flags;
2533         int ret = 0;
2534         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2535
2536         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2537             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2538                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2539                                        cmd->prot_length, true, false);
2540                 if (ret < 0)
2541                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2542         }
2543
2544         /*
2545          * Determine if the TCM fabric module has already allocated physical
2546          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2547          * beforehand.
2548          */
2549         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2550             cmd->data_length) {
2551
2552                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2553                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2554                         u32 bidi_length;
2555
2556                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2557                                 bidi_length = cmd->t_task_nolb *
2558                                               cmd->se_dev->dev_attrib.block_size;
2559                         else
2560                                 bidi_length = cmd->data_length;
2561
2562                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2563                                                &cmd->t_bidi_data_nents,
2564                                                bidi_length, zero_flag, false);
2565                         if (ret < 0)
2566                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2567                 }
2568
2569                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2570                                        cmd->data_length, zero_flag, false);
2571                 if (ret < 0)
2572                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2573         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2574                     cmd->data_length) {
2575                 /*
2576                  * Special case for COMPARE_AND_WRITE with fabrics
2577                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2578                  */
2579                 u32 caw_length = cmd->t_task_nolb *
2580                                  cmd->se_dev->dev_attrib.block_size;
2581
2582                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2583                                        &cmd->t_bidi_data_nents,
2584                                        caw_length, zero_flag, false);
2585                 if (ret < 0)
2586                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2587         }
2588         /*
2589          * If this command is not a write we can execute it right here,
2590          * for write buffers we need to notify the fabric driver first
2591          * and let it call back once the write buffers are ready.
2592          */
2593         target_add_to_state_list(cmd);
2594         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2595                 target_execute_cmd(cmd);
2596                 return 0;
2597         }
2598
2599         spin_lock_irqsave(&cmd->t_state_lock, flags);
2600         cmd->t_state = TRANSPORT_WRITE_PENDING;
2601         /*
2602          * Determine if frontend context caller is requesting the stopping of
2603          * this command for frontend exceptions.
2604          */
2605         if (cmd->transport_state & CMD_T_STOP &&
2606             !cmd->se_tfo->write_pending_must_be_called) {
2607                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2608                          __func__, __LINE__, cmd->tag);
2609
2610                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2611
2612                 complete_all(&cmd->t_transport_stop_comp);
2613                 return 0;
2614         }
2615         cmd->transport_state &= ~CMD_T_ACTIVE;
2616         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2617
2618         ret = cmd->se_tfo->write_pending(cmd);
2619         if (ret)
2620                 goto queue_full;
2621
2622         return 0;
2623
2624 queue_full:
2625         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2626         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2627         return 0;
2628 }
2629 EXPORT_SYMBOL(transport_generic_new_cmd);
2630
2631 static void transport_write_pending_qf(struct se_cmd *cmd)
2632 {
2633         unsigned long flags;
2634         int ret;
2635         bool stop;
2636
2637         spin_lock_irqsave(&cmd->t_state_lock, flags);
2638         stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2639         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2640
2641         if (stop) {
2642                 pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2643                         __func__, __LINE__, cmd->tag);
2644                 complete_all(&cmd->t_transport_stop_comp);
2645                 return;
2646         }
2647
2648         ret = cmd->se_tfo->write_pending(cmd);
2649         if (ret) {
2650                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2651                          cmd);
2652                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2653         }
2654 }
2655
2656 static bool
2657 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2658                            unsigned long *flags);
2659
2660 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2661 {
2662         unsigned long flags;
2663
2664         spin_lock_irqsave(&cmd->t_state_lock, flags);
2665         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2666         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2667 }
2668
2669 /*
2670  * Call target_put_sess_cmd() and wait until target_release_cmd_kref(@cmd) has
2671  * finished.
2672  */
2673 void target_put_cmd_and_wait(struct se_cmd *cmd)
2674 {
2675         DECLARE_COMPLETION_ONSTACK(compl);
2676
2677         WARN_ON_ONCE(cmd->abrt_compl);
2678         cmd->abrt_compl = &compl;
2679         target_put_sess_cmd(cmd);
2680         wait_for_completion(&compl);
2681 }
2682
2683 /*
2684  * This function is called by frontend drivers after processing of a command
2685  * has finished.
2686  *
2687  * The protocol for ensuring that either the regular frontend command
2688  * processing flow or target_handle_abort() code drops one reference is as
2689  * follows:
2690  * - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
2691  *   the frontend driver to call this function synchronously or asynchronously.
2692  *   That will cause one reference to be dropped.
2693  * - During regular command processing the target core sets CMD_T_COMPLETE
2694  *   before invoking one of the .queue_*() functions.
2695  * - The code that aborts commands skips commands and TMFs for which
2696  *   CMD_T_COMPLETE has been set.
2697  * - CMD_T_ABORTED is set atomically after the CMD_T_COMPLETE check for
2698  *   commands that will be aborted.
2699  * - If the CMD_T_ABORTED flag is set but CMD_T_TAS has not been set
2700  *   transport_generic_free_cmd() skips its call to target_put_sess_cmd().
2701  * - For aborted commands for which CMD_T_TAS has been set .queue_status() will
2702  *   be called and will drop a reference.
2703  * - For aborted commands for which CMD_T_TAS has not been set .aborted_task()
2704  *   will be called. target_handle_abort() will drop the final reference.
2705  */
2706 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2707 {
2708         DECLARE_COMPLETION_ONSTACK(compl);
2709         int ret = 0;
2710         bool aborted = false, tas = false;
2711
2712         if (wait_for_tasks)
2713                 target_wait_free_cmd(cmd, &aborted, &tas);
2714
2715         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD) {
2716                 /*
2717                  * Handle WRITE failure case where transport_generic_new_cmd()
2718                  * has already added se_cmd to state_list, but fabric has
2719                  * failed command before I/O submission.
2720                  */
2721                 if (cmd->state_active)
2722                         target_remove_from_state_list(cmd);
2723
2724                 if (cmd->se_lun)
2725                         transport_lun_remove_cmd(cmd);
2726         }
2727         if (aborted)
2728                 cmd->free_compl = &compl;
2729         ret = target_put_sess_cmd(cmd);
2730         if (aborted) {
2731                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2732                 wait_for_completion(&compl);
2733                 ret = 1;
2734         }
2735         return ret;
2736 }
2737 EXPORT_SYMBOL(transport_generic_free_cmd);
2738
2739 /**
2740  * target_get_sess_cmd - Add command to active ->sess_cmd_list
2741  * @se_cmd:     command descriptor to add
2742  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2743  */
2744 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2745 {
2746         struct se_session *se_sess = se_cmd->se_sess;
2747         unsigned long flags;
2748         int ret = 0;
2749
2750         /*
2751          * Add a second kref if the fabric caller is expecting to handle
2752          * fabric acknowledgement that requires two target_put_sess_cmd()
2753          * invocations before se_cmd descriptor release.
2754          */
2755         if (ack_kref) {
2756                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2757                         return -EINVAL;
2758
2759                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2760         }
2761
2762         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2763         if (se_sess->sess_tearing_down) {
2764                 ret = -ESHUTDOWN;
2765                 goto out;
2766         }
2767         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2768         percpu_ref_get(&se_sess->cmd_count);
2769 out:
2770         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2771
2772         if (ret && ack_kref)
2773                 target_put_sess_cmd(se_cmd);
2774
2775         return ret;
2776 }
2777 EXPORT_SYMBOL(target_get_sess_cmd);
2778
2779 static void target_free_cmd_mem(struct se_cmd *cmd)
2780 {
2781         transport_free_pages(cmd);
2782
2783         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2784                 core_tmr_release_req(cmd->se_tmr_req);
2785         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2786                 kfree(cmd->t_task_cdb);
2787 }
2788
2789 static void target_release_cmd_kref(struct kref *kref)
2790 {
2791         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2792         struct se_session *se_sess = se_cmd->se_sess;
2793         struct completion *free_compl = se_cmd->free_compl;
2794         struct completion *abrt_compl = se_cmd->abrt_compl;
2795         unsigned long flags;
2796
2797         if (se_sess) {
2798                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2799                 list_del_init(&se_cmd->se_cmd_list);
2800                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2801         }
2802
2803         target_free_cmd_mem(se_cmd);
2804         se_cmd->se_tfo->release_cmd(se_cmd);
2805         if (free_compl)
2806                 complete(free_compl);
2807         if (abrt_compl)
2808                 complete(abrt_compl);
2809
2810         percpu_ref_put(&se_sess->cmd_count);
2811 }
2812
2813 /**
2814  * target_put_sess_cmd - decrease the command reference count
2815  * @se_cmd:     command to drop a reference from
2816  *
2817  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2818  * refcount to drop to zero. Returns zero otherwise.
2819  */
2820 int target_put_sess_cmd(struct se_cmd *se_cmd)
2821 {
2822         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2823 }
2824 EXPORT_SYMBOL(target_put_sess_cmd);
2825
2826 static const char *data_dir_name(enum dma_data_direction d)
2827 {
2828         switch (d) {
2829         case DMA_BIDIRECTIONAL: return "BIDI";
2830         case DMA_TO_DEVICE:     return "WRITE";
2831         case DMA_FROM_DEVICE:   return "READ";
2832         case DMA_NONE:          return "NONE";
2833         }
2834
2835         return "(?)";
2836 }
2837
2838 static const char *cmd_state_name(enum transport_state_table t)
2839 {
2840         switch (t) {
2841         case TRANSPORT_NO_STATE:        return "NO_STATE";
2842         case TRANSPORT_NEW_CMD:         return "NEW_CMD";
2843         case TRANSPORT_WRITE_PENDING:   return "WRITE_PENDING";
2844         case TRANSPORT_PROCESSING:      return "PROCESSING";
2845         case TRANSPORT_COMPLETE:        return "COMPLETE";
2846         case TRANSPORT_ISTATE_PROCESSING:
2847                                         return "ISTATE_PROCESSING";
2848         case TRANSPORT_COMPLETE_QF_WP:  return "COMPLETE_QF_WP";
2849         case TRANSPORT_COMPLETE_QF_OK:  return "COMPLETE_QF_OK";
2850         case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
2851         }
2852
2853         return "(?)";
2854 }
2855
2856 static void target_append_str(char **str, const char *txt)
2857 {
2858         char *prev = *str;
2859
2860         *str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
2861                 kstrdup(txt, GFP_ATOMIC);
2862         kfree(prev);
2863 }
2864
2865 /*
2866  * Convert a transport state bitmask into a string. The caller is
2867  * responsible for freeing the returned pointer.
2868  */
2869 static char *target_ts_to_str(u32 ts)
2870 {
2871         char *str = NULL;
2872
2873         if (ts & CMD_T_ABORTED)
2874                 target_append_str(&str, "aborted");
2875         if (ts & CMD_T_ACTIVE)
2876                 target_append_str(&str, "active");
2877         if (ts & CMD_T_COMPLETE)
2878                 target_append_str(&str, "complete");
2879         if (ts & CMD_T_SENT)
2880                 target_append_str(&str, "sent");
2881         if (ts & CMD_T_STOP)
2882                 target_append_str(&str, "stop");
2883         if (ts & CMD_T_FABRIC_STOP)
2884                 target_append_str(&str, "fabric_stop");
2885
2886         return str;
2887 }
2888
2889 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
2890 {
2891         switch (tmf) {
2892         case TMR_ABORT_TASK:            return "ABORT_TASK";
2893         case TMR_ABORT_TASK_SET:        return "ABORT_TASK_SET";
2894         case TMR_CLEAR_ACA:             return "CLEAR_ACA";
2895         case TMR_CLEAR_TASK_SET:        return "CLEAR_TASK_SET";
2896         case TMR_LUN_RESET:             return "LUN_RESET";
2897         case TMR_TARGET_WARM_RESET:     return "TARGET_WARM_RESET";
2898         case TMR_TARGET_COLD_RESET:     return "TARGET_COLD_RESET";
2899         case TMR_UNKNOWN:               break;
2900         }
2901         return "(?)";
2902 }
2903
2904 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
2905 {
2906         char *ts_str = target_ts_to_str(cmd->transport_state);
2907         const u8 *cdb = cmd->t_task_cdb;
2908         struct se_tmr_req *tmf = cmd->se_tmr_req;
2909
2910         if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2911                 pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
2912                          pfx, cdb[0], cdb[1], cmd->tag,
2913                          data_dir_name(cmd->data_direction),
2914                          cmd->se_tfo->get_cmd_state(cmd),
2915                          cmd_state_name(cmd->t_state), cmd->data_length,
2916                          kref_read(&cmd->cmd_kref), ts_str);
2917         } else {
2918                 pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
2919                          pfx, target_tmf_name(tmf->function), cmd->tag,
2920                          tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
2921                          cmd_state_name(cmd->t_state),
2922                          kref_read(&cmd->cmd_kref), ts_str);
2923         }
2924         kfree(ts_str);
2925 }
2926 EXPORT_SYMBOL(target_show_cmd);
2927
2928 /**
2929  * target_sess_cmd_list_set_waiting - Set sess_tearing_down so no new commands are queued.
2930  * @se_sess:    session to flag
2931  */
2932 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2933 {
2934         unsigned long flags;
2935
2936         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2937         se_sess->sess_tearing_down = 1;
2938         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2939
2940         percpu_ref_kill(&se_sess->cmd_count);
2941 }
2942 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2943
2944 /**
2945  * target_wait_for_sess_cmds - Wait for outstanding commands
2946  * @se_sess:    session to wait for active I/O
2947  */
2948 void target_wait_for_sess_cmds(struct se_session *se_sess)
2949 {
2950         struct se_cmd *cmd;
2951         int ret;
2952
2953         WARN_ON_ONCE(!se_sess->sess_tearing_down);
2954
2955         do {
2956                 ret = wait_event_timeout(se_sess->cmd_list_wq,
2957                                 percpu_ref_is_zero(&se_sess->cmd_count),
2958                                 180 * HZ);
2959                 list_for_each_entry(cmd, &se_sess->sess_cmd_list, se_cmd_list)
2960                         target_show_cmd("session shutdown: still waiting for ",
2961                                         cmd);
2962         } while (ret <= 0);
2963 }
2964 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2965
2966 /*
2967  * Prevent that new percpu_ref_tryget_live() calls succeed and wait until
2968  * all references to the LUN have been released. Called during LUN shutdown.
2969  */
2970 void transport_clear_lun_ref(struct se_lun *lun)
2971 {
2972         percpu_ref_kill(&lun->lun_ref);
2973         wait_for_completion(&lun->lun_shutdown_comp);
2974 }
2975
2976 static bool
2977 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2978                            bool *aborted, bool *tas, unsigned long *flags)
2979         __releases(&cmd->t_state_lock)
2980         __acquires(&cmd->t_state_lock)
2981 {
2982
2983         assert_spin_locked(&cmd->t_state_lock);
2984         WARN_ON_ONCE(!irqs_disabled());
2985
2986         if (fabric_stop)
2987                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2988
2989         if (cmd->transport_state & CMD_T_ABORTED)
2990                 *aborted = true;
2991
2992         if (cmd->transport_state & CMD_T_TAS)
2993                 *tas = true;
2994
2995         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2996             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2997                 return false;
2998
2999         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
3000             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3001                 return false;
3002
3003         if (!(cmd->transport_state & CMD_T_ACTIVE))
3004                 return false;
3005
3006         if (fabric_stop && *aborted)
3007                 return false;
3008
3009         cmd->transport_state |= CMD_T_STOP;
3010
3011         target_show_cmd("wait_for_tasks: Stopping ", cmd);
3012
3013         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
3014
3015         while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
3016                                             180 * HZ))
3017                 target_show_cmd("wait for tasks: ", cmd);
3018
3019         spin_lock_irqsave(&cmd->t_state_lock, *flags);
3020         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
3021
3022         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
3023                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
3024
3025         return true;
3026 }
3027
3028 /**
3029  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3030  * @cmd: command to wait on
3031  */
3032 bool transport_wait_for_tasks(struct se_cmd *cmd)
3033 {
3034         unsigned long flags;
3035         bool ret, aborted = false, tas = false;
3036
3037         spin_lock_irqsave(&cmd->t_state_lock, flags);
3038         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3039         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3040
3041         return ret;
3042 }
3043 EXPORT_SYMBOL(transport_wait_for_tasks);
3044
3045 struct sense_info {
3046         u8 key;
3047         u8 asc;
3048         u8 ascq;
3049         bool add_sector_info;
3050 };
3051
3052 static const struct sense_info sense_info_table[] = {
3053         [TCM_NO_SENSE] = {
3054                 .key = NOT_READY
3055         },
3056         [TCM_NON_EXISTENT_LUN] = {
3057                 .key = ILLEGAL_REQUEST,
3058                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3059         },
3060         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
3061                 .key = ILLEGAL_REQUEST,
3062                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3063         },
3064         [TCM_SECTOR_COUNT_TOO_MANY] = {
3065                 .key = ILLEGAL_REQUEST,
3066                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3067         },
3068         [TCM_UNKNOWN_MODE_PAGE] = {
3069                 .key = ILLEGAL_REQUEST,
3070                 .asc = 0x24, /* INVALID FIELD IN CDB */
3071         },
3072         [TCM_CHECK_CONDITION_ABORT_CMD] = {
3073                 .key = ABORTED_COMMAND,
3074                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3075                 .ascq = 0x03,
3076         },
3077         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
3078                 .key = ABORTED_COMMAND,
3079                 .asc = 0x0c, /* WRITE ERROR */
3080                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3081         },
3082         [TCM_INVALID_CDB_FIELD] = {
3083                 .key = ILLEGAL_REQUEST,
3084                 .asc = 0x24, /* INVALID FIELD IN CDB */
3085         },
3086         [TCM_INVALID_PARAMETER_LIST] = {
3087                 .key = ILLEGAL_REQUEST,
3088                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3089         },
3090         [TCM_TOO_MANY_TARGET_DESCS] = {
3091                 .key = ILLEGAL_REQUEST,
3092                 .asc = 0x26,
3093                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3094         },
3095         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3096                 .key = ILLEGAL_REQUEST,
3097                 .asc = 0x26,
3098                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3099         },
3100         [TCM_TOO_MANY_SEGMENT_DESCS] = {
3101                 .key = ILLEGAL_REQUEST,
3102                 .asc = 0x26,
3103                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3104         },
3105         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3106                 .key = ILLEGAL_REQUEST,
3107                 .asc = 0x26,
3108                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3109         },
3110         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3111                 .key = ILLEGAL_REQUEST,
3112                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3113         },
3114         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3115                 .key = ILLEGAL_REQUEST,
3116                 .asc = 0x0c, /* WRITE ERROR */
3117                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3118         },
3119         [TCM_SERVICE_CRC_ERROR] = {
3120                 .key = ABORTED_COMMAND,
3121                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3122                 .ascq = 0x05, /* N/A */
3123         },
3124         [TCM_SNACK_REJECTED] = {
3125                 .key = ABORTED_COMMAND,
3126                 .asc = 0x11, /* READ ERROR */
3127                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3128         },
3129         [TCM_WRITE_PROTECTED] = {
3130                 .key = DATA_PROTECT,
3131                 .asc = 0x27, /* WRITE PROTECTED */
3132         },
3133         [TCM_ADDRESS_OUT_OF_RANGE] = {
3134                 .key = ILLEGAL_REQUEST,
3135                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3136         },
3137         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3138                 .key = UNIT_ATTENTION,
3139         },
3140         [TCM_CHECK_CONDITION_NOT_READY] = {
3141                 .key = NOT_READY,
3142         },
3143         [TCM_MISCOMPARE_VERIFY] = {
3144                 .key = MISCOMPARE,
3145                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3146                 .ascq = 0x00,
3147         },
3148         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3149                 .key = ABORTED_COMMAND,
3150                 .asc = 0x10,
3151                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3152                 .add_sector_info = true,
3153         },
3154         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3155                 .key = ABORTED_COMMAND,
3156                 .asc = 0x10,
3157                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3158                 .add_sector_info = true,
3159         },
3160         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3161                 .key = ABORTED_COMMAND,
3162                 .asc = 0x10,
3163                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3164                 .add_sector_info = true,
3165         },
3166         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3167                 .key = COPY_ABORTED,
3168                 .asc = 0x0d,
3169                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3170
3171         },
3172         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3173                 /*
3174                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
3175                  * Solaris initiators.  Returning NOT READY instead means the
3176                  * operations will be retried a finite number of times and we
3177                  * can survive intermittent errors.
3178                  */
3179                 .key = NOT_READY,
3180                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3181         },
3182         [TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3183                 /*
3184                  * From spc4r22 section5.7.7,5.7.8
3185                  * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3186                  * or a REGISTER AND IGNORE EXISTING KEY service action or
3187                  * REGISTER AND MOVE service actionis attempted,
3188                  * but there are insufficient device server resources to complete the
3189                  * operation, then the command shall be terminated with CHECK CONDITION
3190                  * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3191                  * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3192                  */
3193                 .key = ILLEGAL_REQUEST,
3194                 .asc = 0x55,
3195                 .ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3196         },
3197 };
3198
3199 /**
3200  * translate_sense_reason - translate a sense reason into T10 key, asc and ascq
3201  * @cmd: SCSI command in which the resulting sense buffer or SCSI status will
3202  *   be stored.
3203  * @reason: LIO sense reason code. If this argument has the value
3204  *   TCM_CHECK_CONDITION_UNIT_ATTENTION, try to dequeue a unit attention. If
3205  *   dequeuing a unit attention fails due to multiple commands being processed
3206  *   concurrently, set the command status to BUSY.
3207  *
3208  * Return: 0 upon success or -EINVAL if the sense buffer is too small.
3209  */
3210 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3211 {
3212         const struct sense_info *si;
3213         u8 *buffer = cmd->sense_buffer;
3214         int r = (__force int)reason;
3215         u8 key, asc, ascq;
3216         bool desc_format = target_sense_desc_format(cmd->se_dev);
3217
3218         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
3219                 si = &sense_info_table[r];
3220         else
3221                 si = &sense_info_table[(__force int)
3222                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3223
3224         key = si->key;
3225         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3226                 if (!core_scsi3_ua_for_check_condition(cmd, &key, &asc,
3227                                                        &ascq)) {
3228                         cmd->scsi_status = SAM_STAT_BUSY;
3229                         return;
3230                 }
3231         } else if (si->asc == 0) {
3232                 WARN_ON_ONCE(cmd->scsi_asc == 0);
3233                 asc = cmd->scsi_asc;
3234                 ascq = cmd->scsi_ascq;
3235         } else {
3236                 asc = si->asc;
3237                 ascq = si->ascq;
3238         }
3239
3240         cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3241         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3242         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3243         scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
3244         if (si->add_sector_info)
3245                 WARN_ON_ONCE(scsi_set_sense_information(buffer,
3246                                                         cmd->scsi_sense_length,
3247                                                         cmd->bad_sector) < 0);
3248 }
3249
3250 int
3251 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3252                 sense_reason_t reason, int from_transport)
3253 {
3254         unsigned long flags;
3255
3256         WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3257
3258         spin_lock_irqsave(&cmd->t_state_lock, flags);
3259         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3260                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3261                 return 0;
3262         }
3263         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3264         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3265
3266         if (!from_transport)
3267                 translate_sense_reason(cmd, reason);
3268
3269         trace_target_cmd_complete(cmd);
3270         return cmd->se_tfo->queue_status(cmd);
3271 }
3272 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3273
3274 static void target_tmr_work(struct work_struct *work)
3275 {
3276         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3277         struct se_device *dev = cmd->se_dev;
3278         struct se_tmr_req *tmr = cmd->se_tmr_req;
3279         int ret;
3280
3281         if (cmd->transport_state & CMD_T_ABORTED)
3282                 goto aborted;
3283
3284         switch (tmr->function) {
3285         case TMR_ABORT_TASK:
3286                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3287                 break;
3288         case TMR_ABORT_TASK_SET:
3289         case TMR_CLEAR_ACA:
3290         case TMR_CLEAR_TASK_SET:
3291                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3292                 break;
3293         case TMR_LUN_RESET:
3294                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3295                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3296                                          TMR_FUNCTION_REJECTED;
3297                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3298                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3299                                                cmd->orig_fe_lun, 0x29,
3300                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3301                 }
3302                 break;
3303         case TMR_TARGET_WARM_RESET:
3304                 tmr->response = TMR_FUNCTION_REJECTED;
3305                 break;
3306         case TMR_TARGET_COLD_RESET:
3307                 tmr->response = TMR_FUNCTION_REJECTED;
3308                 break;
3309         default:
3310                 pr_err("Unknown TMR function: 0x%02x.\n",
3311                                 tmr->function);
3312                 tmr->response = TMR_FUNCTION_REJECTED;
3313                 break;
3314         }
3315
3316         if (cmd->transport_state & CMD_T_ABORTED)
3317                 goto aborted;
3318
3319         cmd->se_tfo->queue_tm_rsp(cmd);
3320
3321         transport_cmd_check_stop_to_fabric(cmd);
3322         return;
3323
3324 aborted:
3325         target_handle_abort(cmd);
3326 }
3327
3328 int transport_generic_handle_tmr(
3329         struct se_cmd *cmd)
3330 {
3331         unsigned long flags;
3332         bool aborted = false;
3333
3334         spin_lock_irqsave(&cmd->t_state_lock, flags);
3335         if (cmd->transport_state & CMD_T_ABORTED) {
3336                 aborted = true;
3337         } else {
3338                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3339                 cmd->transport_state |= CMD_T_ACTIVE;
3340         }
3341         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3342
3343         if (aborted) {
3344                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d ref_tag: %llu tag: %llu\n",
3345                                     cmd->se_tmr_req->function,
3346                                     cmd->se_tmr_req->ref_task_tag, cmd->tag);
3347                 target_handle_abort(cmd);
3348                 return 0;
3349         }
3350
3351         INIT_WORK(&cmd->work, target_tmr_work);
3352         schedule_work(&cmd->work);
3353         return 0;
3354 }
3355 EXPORT_SYMBOL(transport_generic_handle_tmr);
3356
3357 bool
3358 target_check_wce(struct se_device *dev)
3359 {
3360         bool wce = false;
3361
3362         if (dev->transport->get_write_cache)
3363                 wce = dev->transport->get_write_cache(dev);
3364         else if (dev->dev_attrib.emulate_write_cache > 0)
3365                 wce = true;
3366
3367         return wce;
3368 }
3369
3370 bool
3371 target_check_fua(struct se_device *dev)
3372 {
3373         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3374 }