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