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 transport_handle_queue_full(struct se_cmd *cmd,
  68                 struct se_device *dev);
  69 static int transport_put_cmd(struct se_cmd *cmd);
  70 static void target_complete_ok_work(struct work_struct *work);
  71
  72 int init_se_kmem_caches(void)
  73 {
  74         se_sess_cache = kmem_cache_create("se_sess_cache",
  75                         sizeof(struct se_session), __alignof__(struct se_session),
  76                         0, NULL);
  77         if (!se_sess_cache) {
  78                 pr_err("kmem_cache_create() for struct se_session"
  79                                 " failed\n");
  80                 goto out;
  81         }
  82         se_ua_cache = kmem_cache_create("se_ua_cache",
  83                         sizeof(struct se_ua), __alignof__(struct se_ua),
  84                         0, NULL);
  85         if (!se_ua_cache) {
  86                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  87                 goto out_free_sess_cache;
  88         }
  89         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  90                         sizeof(struct t10_pr_registration),
  91                         __alignof__(struct t10_pr_registration), 0, NULL);
  92         if (!t10_pr_reg_cache) {
  93                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  94                                 " failed\n");
  95                 goto out_free_ua_cache;
  96         }
  97         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  98                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  99                         0, NULL);
 100         if (!t10_alua_lu_gp_cache) {
 101                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 102                                 " failed\n");
 103                 goto out_free_pr_reg_cache;
 104         }
 105         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 106                         sizeof(struct t10_alua_lu_gp_member),
 107                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 108         if (!t10_alua_lu_gp_mem_cache) {
 109                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 110                                 "cache failed\n");
 111                 goto out_free_lu_gp_cache;
 112         }
 113         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 114                         sizeof(struct t10_alua_tg_pt_gp),
 115                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 116         if (!t10_alua_tg_pt_gp_cache) {
 117                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 118                                 "cache failed\n");
 119                 goto out_free_lu_gp_mem_cache;
 120         }
 121         t10_alua_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 = request_module("target_core_iblock");
 209         if (ret != 0)
 210                 pr_err("Unable to load target_core_iblock\n");
 211
 212         ret = request_module("target_core_file");
 213         if (ret != 0)
 214                 pr_err("Unable to load target_core_file\n");
 215
 216         ret = request_module("target_core_pscsi");
 217         if (ret != 0)
 218                 pr_err("Unable to load target_core_pscsi\n");
 219
 220         ret = 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 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
 228 {
 229         struct se_session *se_sess;
 230
 231         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 232         if (!se_sess) {
 233                 pr_err("Unable to allocate struct se_session from"
 234                                 " se_sess_cache\n");
 235                 return ERR_PTR(-ENOMEM);
 236         }
 237         INIT_LIST_HEAD(&se_sess->sess_list);
 238         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 239         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 240         INIT_LIST_HEAD(&se_sess->sess_wait_list);
 241         spin_lock_init(&se_sess->sess_cmd_lock);
 242         se_sess->sup_prot_ops = sup_prot_ops;
 243
 244         return se_sess;
 245 }
 246 EXPORT_SYMBOL(transport_init_session);
 247
 248 int transport_alloc_session_tags(struct se_session *se_sess,
 249                                  unsigned int tag_num, unsigned int tag_size)
 250 {
 251         int rc;
 252
 253         se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
 254                                         GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
 255         if (!se_sess->sess_cmd_map) {
 256                 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
 257                 if (!se_sess->sess_cmd_map) {
 258                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 259                         return -ENOMEM;
 260                 }
 261         }
 262
 263         rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
 264         if (rc < 0) {
 265                 pr_err("Unable to init se_sess->sess_tag_pool,"
 266                         " tag_num: %u\n", tag_num);
 267                 kvfree(se_sess->sess_cmd_map);
 268                 se_sess->sess_cmd_map = NULL;
 269                 return -ENOMEM;
 270         }
 271
 272         return 0;
 273 }
 274 EXPORT_SYMBOL(transport_alloc_session_tags);
 275
 276 struct se_session *transport_init_session_tags(unsigned int tag_num,
 277                                                unsigned int tag_size,
 278                                                enum target_prot_op sup_prot_ops)
 279 {
 280         struct se_session *se_sess;
 281         int rc;
 282
 283         if (tag_num != 0 && !tag_size) {
 284                 pr_err("init_session_tags called with percpu-ida tag_num:"
 285                        " %u, but zero tag_size\n", tag_num);
 286                 return ERR_PTR(-EINVAL);
 287         }
 288         if (!tag_num && tag_size) {
 289                 pr_err("init_session_tags called with percpu-ida tag_size:"
 290                        " %u, but zero tag_num\n", tag_size);
 291                 return ERR_PTR(-EINVAL);
 292         }
 293
 294         se_sess = transport_init_session(sup_prot_ops);
 295         if (IS_ERR(se_sess))
 296                 return se_sess;
 297
 298         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 299         if (rc < 0) {
 300                 transport_free_session(se_sess);
 301                 return ERR_PTR(-ENOMEM);
 302         }
 303
 304         return se_sess;
 305 }
 306 EXPORT_SYMBOL(transport_init_session_tags);
 307
 308 /*
 309  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 310  */
 311 void __transport_register_session(
 312         struct se_portal_group *se_tpg,
 313         struct se_node_acl *se_nacl,
 314         struct se_session *se_sess,
 315         void *fabric_sess_ptr)
 316 {
 317         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 318         unsigned char buf[PR_REG_ISID_LEN];
 319
 320         se_sess->se_tpg = se_tpg;
 321         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 322         /*
 323          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 324          *
 325          * Only set for struct se_session's that will actually be moving I/O.
 326          * eg: *NOT* discovery sessions.
 327          */
 328         if (se_nacl) {
 329                 /*
 330                  *
 331                  * Determine if fabric allows for T10-PI feature bits exposed to
 332                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 333                  *
 334                  * If so, then always save prot_type on a per se_node_acl node
 335                  * basis and re-instate the previous sess_prot_type to avoid
 336                  * disabling PI from below any previously initiator side
 337                  * registered LUNs.
 338                  */
 339                 if (se_nacl->saved_prot_type)
 340                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 341                 else if (tfo->tpg_check_prot_fabric_only)
 342                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 343                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 344                 /*
 345                  * If the fabric module supports an ISID based TransportID,
 346                  * save this value in binary from the fabric I_T Nexus now.
 347                  */
 348                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 349                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 350                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 351                                         &buf[0], PR_REG_ISID_LEN);
 352                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 353                 }
 354
 355                 spin_lock_irq(&se_nacl->nacl_sess_lock);
 356                 /*
 357                  * The se_nacl->nacl_sess pointer will be set to the
 358                  * last active I_T Nexus for each struct se_node_acl.
 359                  */
 360                 se_nacl->nacl_sess = se_sess;
 361
 362                 list_add_tail(&se_sess->sess_acl_list,
 363                               &se_nacl->acl_sess_list);
 364                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
 365         }
 366         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 367
 368         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 369                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 370 }
 371 EXPORT_SYMBOL(__transport_register_session);
 372
 373 void transport_register_session(
 374         struct se_portal_group *se_tpg,
 375         struct se_node_acl *se_nacl,
 376         struct se_session *se_sess,
 377         void *fabric_sess_ptr)
 378 {
 379         unsigned long flags;
 380
 381         spin_lock_irqsave(&se_tpg->session_lock, flags);
 382         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 383         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 384 }
 385 EXPORT_SYMBOL(transport_register_session);
 386
 387 struct se_session *
 388 target_alloc_session(struct se_portal_group *tpg,
 389                      unsigned int tag_num, unsigned int tag_size,
 390                      enum target_prot_op prot_op,
 391                      const char *initiatorname, void *private,
 392                      int (*callback)(struct se_portal_group *,
 393                                      struct se_session *, void *))
 394 {
 395         struct se_session *sess;
 396
 397         /*
 398          * If the fabric driver is using percpu-ida based pre allocation
 399          * of I/O descriptor tags, go ahead and perform that setup now..
 400          */
 401         if (tag_num != 0)
 402                 sess = transport_init_session_tags(tag_num, tag_size, prot_op);
 403         else
 404                 sess = transport_init_session(prot_op);
 405
 406         if (IS_ERR(sess))
 407                 return sess;
 408
 409         sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
 410                                         (unsigned char *)initiatorname);
 411         if (!sess->se_node_acl) {
 412                 transport_free_session(sess);
 413                 return ERR_PTR(-EACCES);
 414         }
 415         /*
 416          * Go ahead and perform any remaining fabric setup that is
 417          * required before transport_register_session().
 418          */
 419         if (callback != NULL) {
 420                 int rc = callback(tpg, sess, private);
 421                 if (rc) {
 422                         transport_free_session(sess);
 423                         return ERR_PTR(rc);
 424                 }
 425         }
 426
 427         transport_register_session(tpg, sess->se_node_acl, sess, private);
 428         return sess;
 429 }
 430 EXPORT_SYMBOL(target_alloc_session);
 431
 432 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 433 {
 434         struct se_session *se_sess;
 435         ssize_t len = 0;
 436
 437         spin_lock_bh(&se_tpg->session_lock);
 438         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 439                 if (!se_sess->se_node_acl)
 440                         continue;
 441                 if (!se_sess->se_node_acl->dynamic_node_acl)
 442                         continue;
 443                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 444                         break;
 445
 446                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 447                                 se_sess->se_node_acl->initiatorname);
 448                 len += 1; /* Include NULL terminator */
 449         }
 450         spin_unlock_bh(&se_tpg->session_lock);
 451
 452         return len;
 453 }
 454 EXPORT_SYMBOL(target_show_dynamic_sessions);
 455
 456 static void target_complete_nacl(struct kref *kref)
 457 {
 458         struct se_node_acl *nacl = container_of(kref,
 459                                 struct se_node_acl, acl_kref);
 460         struct se_portal_group *se_tpg = nacl->se_tpg;
 461
 462         if (!nacl->dynamic_stop) {
 463                 complete(&nacl->acl_free_comp);
 464                 return;
 465         }
 466
 467         mutex_lock(&se_tpg->acl_node_mutex);
 468         list_del(&nacl->acl_list);
 469         mutex_unlock(&se_tpg->acl_node_mutex);
 470
 471         core_tpg_wait_for_nacl_pr_ref(nacl);
 472         core_free_device_list_for_node(nacl, se_tpg);
 473         kfree(nacl);
 474 }
 475
 476 void target_put_nacl(struct se_node_acl *nacl)
 477 {
 478         kref_put(&nacl->acl_kref, target_complete_nacl);
 479 }
 480 EXPORT_SYMBOL(target_put_nacl);
 481
 482 void transport_deregister_session_configfs(struct se_session *se_sess)
 483 {
 484         struct se_node_acl *se_nacl;
 485         unsigned long flags;
 486         /*
 487          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 488          */
 489         se_nacl = se_sess->se_node_acl;
 490         if (se_nacl) {
 491                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 492                 if (!list_empty(&se_sess->sess_acl_list))
 493                         list_del_init(&se_sess->sess_acl_list);
 494                 /*
 495                  * If the session list is empty, then clear the pointer.
 496                  * Otherwise, set the struct se_session pointer from the tail
 497                  * element of the per struct se_node_acl active session list.
 498                  */
 499                 if (list_empty(&se_nacl->acl_sess_list))
 500                         se_nacl->nacl_sess = NULL;
 501                 else {
 502                         se_nacl->nacl_sess = container_of(
 503                                         se_nacl->acl_sess_list.prev,
 504                                         struct se_session, sess_acl_list);
 505                 }
 506                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 507         }
 508 }
 509 EXPORT_SYMBOL(transport_deregister_session_configfs);
 510
 511 void transport_free_session(struct se_session *se_sess)
 512 {
 513         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 514
 515         /*
 516          * Drop the se_node_acl->nacl_kref obtained from within
 517          * core_tpg_get_initiator_node_acl().
 518          */
 519         if (se_nacl) {
 520                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 521                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 522                 unsigned long flags;
 523
 524                 se_sess->se_node_acl = NULL;
 525
 526                 /*
 527                  * Also determine if we need to drop the extra ->cmd_kref if
 528                  * it had been previously dynamically generated, and
 529                  * the endpoint is not caching dynamic ACLs.
 530                  */
 531                 mutex_lock(&se_tpg->acl_node_mutex);
 532                 if (se_nacl->dynamic_node_acl &&
 533                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 534                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 535                         if (list_empty(&se_nacl->acl_sess_list))
 536                                 se_nacl->dynamic_stop = true;
 537                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 538
 539                         if (se_nacl->dynamic_stop)
 540                                 list_del(&se_nacl->acl_list);
 541                 }
 542                 mutex_unlock(&se_tpg->acl_node_mutex);
 543
 544                 if (se_nacl->dynamic_stop)
 545                         target_put_nacl(se_nacl);
 546
 547                 target_put_nacl(se_nacl);
 548         }
 549         if (se_sess->sess_cmd_map) {
 550                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 551                 kvfree(se_sess->sess_cmd_map);
 552         }
 553         kmem_cache_free(se_sess_cache, se_sess);
 554 }
 555 EXPORT_SYMBOL(transport_free_session);
 556
 557 void transport_deregister_session(struct se_session *se_sess)
 558 {
 559         struct se_portal_group *se_tpg = se_sess->se_tpg;
 560         unsigned long flags;
 561
 562         if (!se_tpg) {
 563                 transport_free_session(se_sess);
 564                 return;
 565         }
 566
 567         spin_lock_irqsave(&se_tpg->session_lock, flags);
 568         list_del(&se_sess->sess_list);
 569         se_sess->se_tpg = NULL;
 570         se_sess->fabric_sess_ptr = NULL;
 571         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 572
 573         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 574                 se_tpg->se_tpg_tfo->get_fabric_name());
 575         /*
 576          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 577          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 578          * removal context from within transport_free_session() code.
 579          *
 580          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 581          * to release all remaining generate_node_acl=1 created ACL resources.
 582          */
 583
 584         transport_free_session(se_sess);
 585 }
 586 EXPORT_SYMBOL(transport_deregister_session);
 587
 588 static void target_remove_from_state_list(struct se_cmd *cmd)
 589 {
 590         struct se_device *dev = cmd->se_dev;
 591         unsigned long flags;
 592
 593         if (!dev)
 594                 return;
 595
 596         if (cmd->transport_state & CMD_T_BUSY)
 597                 return;
 598
 599         spin_lock_irqsave(&dev->execute_task_lock, flags);
 600         if (cmd->state_active) {
 601                 list_del(&cmd->state_list);
 602                 cmd->state_active = false;
 603         }
 604         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 605 }
 606
 607 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 608                                     bool write_pending)
 609 {
 610         unsigned long flags;
 611
 612         if (remove_from_lists) {
 613                 target_remove_from_state_list(cmd);
 614
 615                 /*
 616                  * Clear struct se_cmd->se_lun before the handoff to FE.
 617                  */
 618                 cmd->se_lun = NULL;
 619         }
 620
 621         spin_lock_irqsave(&cmd->t_state_lock, flags);
 622         if (write_pending)
 623                 cmd->t_state = TRANSPORT_WRITE_PENDING;
 624
 625         /*
 626          * Determine if frontend context caller is requesting the stopping of
 627          * this command for frontend exceptions.
 628          */
 629         if (cmd->transport_state & CMD_T_STOP) {
 630                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 631                         __func__, __LINE__, cmd->tag);
 632
 633                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 634
 635                 complete_all(&cmd->t_transport_stop_comp);
 636                 return 1;
 637         }
 638
 639         cmd->transport_state &= ~CMD_T_ACTIVE;
 640         if (remove_from_lists) {
 641                 /*
 642                  * Some fabric modules like tcm_loop can release
 643                  * their internally allocated I/O reference now and
 644                  * struct se_cmd now.
 645                  *
 646                  * Fabric modules are expected to return '1' here if the
 647                  * se_cmd being passed is released at this point,
 648                  * or zero if not being released.
 649                  */
 650                 if (cmd->se_tfo->check_stop_free != NULL) {
 651                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 652                         return cmd->se_tfo->check_stop_free(cmd);
 653                 }
 654         }
 655
 656         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 657         return 0;
 658 }
 659
 660 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 661 {
 662         return transport_cmd_check_stop(cmd, true, false);
 663 }
 664
 665 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 666 {
 667         struct se_lun *lun = cmd->se_lun;
 668
 669         if (!lun)
 670                 return;
 671
 672         if (cmpxchg(&cmd->lun_ref_active, true, false))
 673                 percpu_ref_put(&lun->lun_ref);
 674 }
 675
 676 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 677 {
 678         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 679
 680         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 681                 transport_lun_remove_cmd(cmd);
 682         /*
 683          * Allow the fabric driver to unmap any resources before
 684          * releasing the descriptor via TFO->release_cmd()
 685          */
 686         if (remove)
 687                 cmd->se_tfo->aborted_task(cmd);
 688
 689         if (transport_cmd_check_stop_to_fabric(cmd))
 690                 return;
 691         if (remove && ack_kref)
 692                 transport_put_cmd(cmd);
 693 }
 694
 695 static void target_complete_failure_work(struct work_struct *work)
 696 {
 697         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 698
 699         transport_generic_request_failure(cmd,
 700                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 701 }
 702
 703 /*
 704  * Used when asking transport to copy Sense Data from the underlying
 705  * Linux/SCSI struct scsi_cmnd
 706  */
 707 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 708 {
 709         struct se_device *dev = cmd->se_dev;
 710
 711         WARN_ON(!cmd->se_lun);
 712
 713         if (!dev)
 714                 return NULL;
 715
 716         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 717                 return NULL;
 718
 719         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 720
 721         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 722                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 723         return cmd->sense_buffer;
 724 }
 725
 726 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 727 {
 728         struct se_device *dev = cmd->se_dev;
 729         int success = scsi_status == GOOD;
 730         unsigned long flags;
 731
 732         cmd->scsi_status = scsi_status;
 733
 734
 735         spin_lock_irqsave(&cmd->t_state_lock, flags);
 736         cmd->transport_state &= ~CMD_T_BUSY;
 737
 738         if (dev && dev->transport->transport_complete) {
 739                 dev->transport->transport_complete(cmd,
 740                                 cmd->t_data_sg,
 741                                 transport_get_sense_buffer(cmd));
 742                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 743                         success = 1;
 744         }
 745
 746         /*
 747          * Check for case where an explicit ABORT_TASK has been received
 748          * and transport_wait_for_tasks() will be waiting for completion..
 749          */
 750         if (cmd->transport_state & CMD_T_ABORTED ||
 751             cmd->transport_state & CMD_T_STOP) {
 752                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 753                 complete_all(&cmd->t_transport_stop_comp);
 754                 return;
 755         } else if (!success) {
 756                 INIT_WORK(&cmd->work, target_complete_failure_work);
 757         } else {
 758                 INIT_WORK(&cmd->work, target_complete_ok_work);
 759         }
 760
 761         cmd->t_state = TRANSPORT_COMPLETE;
 762         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 763         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 764
 765         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 766                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 767         else
 768                 queue_work(target_completion_wq, &cmd->work);
 769 }
 770 EXPORT_SYMBOL(target_complete_cmd);
 771
 772 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 773 {
 774         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 775                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 776                         cmd->residual_count += cmd->data_length - length;
 777                 } else {
 778                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 779                         cmd->residual_count = cmd->data_length - length;
 780                 }
 781
 782                 cmd->data_length = length;
 783         }
 784
 785         target_complete_cmd(cmd, scsi_status);
 786 }
 787 EXPORT_SYMBOL(target_complete_cmd_with_length);
 788
 789 static void target_add_to_state_list(struct se_cmd *cmd)
 790 {
 791         struct se_device *dev = cmd->se_dev;
 792         unsigned long flags;
 793
 794         spin_lock_irqsave(&dev->execute_task_lock, flags);
 795         if (!cmd->state_active) {
 796                 list_add_tail(&cmd->state_list, &dev->state_list);
 797                 cmd->state_active = true;
 798         }
 799         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 800 }
 801
 802 /*
 803  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 804  */
 805 static void transport_write_pending_qf(struct se_cmd *cmd);
 806 static void transport_complete_qf(struct se_cmd *cmd);
 807
 808 void target_qf_do_work(struct work_struct *work)
 809 {
 810         struct se_device *dev = container_of(work, struct se_device,
 811                                         qf_work_queue);
 812         LIST_HEAD(qf_cmd_list);
 813         struct se_cmd *cmd, *cmd_tmp;
 814
 815         spin_lock_irq(&dev->qf_cmd_lock);
 816         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 817         spin_unlock_irq(&dev->qf_cmd_lock);
 818
 819         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 820                 list_del(&cmd->se_qf_node);
 821                 atomic_dec_mb(&dev->dev_qf_count);
 822
 823                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 824                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 825                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 826                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 827                         : "UNKNOWN");
 828
 829                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 830                         transport_write_pending_qf(cmd);
 831                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
 832                         transport_complete_qf(cmd);
 833         }
 834 }
 835
 836 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 837 {
 838         switch (cmd->data_direction) {
 839         case DMA_NONE:
 840                 return "NONE";
 841         case DMA_FROM_DEVICE:
 842                 return "READ";
 843         case DMA_TO_DEVICE:
 844                 return "WRITE";
 845         case DMA_BIDIRECTIONAL:
 846                 return "BIDI";
 847         default:
 848                 break;
 849         }
 850
 851         return "UNKNOWN";
 852 }
 853
 854 void transport_dump_dev_state(
 855         struct se_device *dev,
 856         char *b,
 857         int *bl)
 858 {
 859         *bl += sprintf(b + *bl, "Status: ");
 860         if (dev->export_count)
 861                 *bl += sprintf(b + *bl, "ACTIVATED");
 862         else
 863                 *bl += sprintf(b + *bl, "DEACTIVATED");
 864
 865         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 866         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 867                 dev->dev_attrib.block_size,
 868                 dev->dev_attrib.hw_max_sectors);
 869         *bl += sprintf(b + *bl, "        ");
 870 }
 871
 872 void transport_dump_vpd_proto_id(
 873         struct t10_vpd *vpd,
 874         unsigned char *p_buf,
 875         int p_buf_len)
 876 {
 877         unsigned char buf[VPD_TMP_BUF_SIZE];
 878         int len;
 879
 880         memset(buf, 0, VPD_TMP_BUF_SIZE);
 881         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 882
 883         switch (vpd->protocol_identifier) {
 884         case 0x00:
 885                 sprintf(buf+len, "Fibre Channel\n");
 886                 break;
 887         case 0x10:
 888                 sprintf(buf+len, "Parallel SCSI\n");
 889                 break;
 890         case 0x20:
 891                 sprintf(buf+len, "SSA\n");
 892                 break;
 893         case 0x30:
 894                 sprintf(buf+len, "IEEE 1394\n");
 895                 break;
 896         case 0x40:
 897                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 898                                 " Protocol\n");
 899                 break;
 900         case 0x50:
 901                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 902                 break;
 903         case 0x60:
 904                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 905                 break;
 906         case 0x70:
 907                 sprintf(buf+len, "Automation/Drive Interface Transport"
 908                                 " Protocol\n");
 909                 break;
 910         case 0x80:
 911                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 912                 break;
 913         default:
 914                 sprintf(buf+len, "Unknown 0x%02x\n",
 915                                 vpd->protocol_identifier);
 916                 break;
 917         }
 918
 919         if (p_buf)
 920                 strncpy(p_buf, buf, p_buf_len);
 921         else
 922                 pr_debug("%s", buf);
 923 }
 924
 925 void
 926 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 927 {
 928         /*
 929          * Check if the Protocol Identifier Valid (PIV) bit is set..
 930          *
 931          * from spc3r23.pdf section 7.5.1
 932          */
 933          if (page_83[1] & 0x80) {
 934                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 935                 vpd->protocol_identifier_set = 1;
 936                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 937         }
 938 }
 939 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 940
 941 int transport_dump_vpd_assoc(
 942         struct t10_vpd *vpd,
 943         unsigned char *p_buf,
 944         int p_buf_len)
 945 {
 946         unsigned char buf[VPD_TMP_BUF_SIZE];
 947         int ret = 0;
 948         int len;
 949
 950         memset(buf, 0, VPD_TMP_BUF_SIZE);
 951         len = sprintf(buf, "T10 VPD Identifier Association: ");
 952
 953         switch (vpd->association) {
 954         case 0x00:
 955                 sprintf(buf+len, "addressed logical unit\n");
 956                 break;
 957         case 0x10:
 958                 sprintf(buf+len, "target port\n");
 959                 break;
 960         case 0x20:
 961                 sprintf(buf+len, "SCSI target device\n");
 962                 break;
 963         default:
 964                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 965                 ret = -EINVAL;
 966                 break;
 967         }
 968
 969         if (p_buf)
 970                 strncpy(p_buf, buf, p_buf_len);
 971         else
 972                 pr_debug("%s", buf);
 973
 974         return ret;
 975 }
 976
 977 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 978 {
 979         /*
 980          * The VPD identification association..
 981          *
 982          * from spc3r23.pdf Section 7.6.3.1 Table 297
 983          */
 984         vpd->association = (page_83[1] & 0x30);
 985         return transport_dump_vpd_assoc(vpd, NULL, 0);
 986 }
 987 EXPORT_SYMBOL(transport_set_vpd_assoc);
 988
 989 int transport_dump_vpd_ident_type(
 990         struct t10_vpd *vpd,
 991         unsigned char *p_buf,
 992         int p_buf_len)
 993 {
 994         unsigned char buf[VPD_TMP_BUF_SIZE];
 995         int ret = 0;
 996         int len;
 997
 998         memset(buf, 0, VPD_TMP_BUF_SIZE);
 999         len = sprintf(buf, "T10 VPD Identifier Type: ");
1000
1001         switch (vpd->device_identifier_type) {
1002         case 0x00:
1003                 sprintf(buf+len, "Vendor specific\n");
1004                 break;
1005         case 0x01:
1006                 sprintf(buf+len, "T10 Vendor ID based\n");
1007                 break;
1008         case 0x02:
1009                 sprintf(buf+len, "EUI-64 based\n");
1010                 break;
1011         case 0x03:
1012                 sprintf(buf+len, "NAA\n");
1013                 break;
1014         case 0x04:
1015                 sprintf(buf+len, "Relative target port identifier\n");
1016                 break;
1017         case 0x08:
1018                 sprintf(buf+len, "SCSI name string\n");
1019                 break;
1020         default:
1021                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1022                                 vpd->device_identifier_type);
1023                 ret = -EINVAL;
1024                 break;
1025         }
1026
1027         if (p_buf) {
1028                 if (p_buf_len < strlen(buf)+1)
1029                         return -EINVAL;
1030                 strncpy(p_buf, buf, p_buf_len);
1031         } else {
1032                 pr_debug("%s", buf);
1033         }
1034
1035         return ret;
1036 }
1037
1038 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1039 {
1040         /*
1041          * The VPD identifier type..
1042          *
1043          * from spc3r23.pdf Section 7.6.3.1 Table 298
1044          */
1045         vpd->device_identifier_type = (page_83[1] & 0x0f);
1046         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1047 }
1048 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1049
1050 int transport_dump_vpd_ident(
1051         struct t10_vpd *vpd,
1052         unsigned char *p_buf,
1053         int p_buf_len)
1054 {
1055         unsigned char buf[VPD_TMP_BUF_SIZE];
1056         int ret = 0;
1057
1058         memset(buf, 0, VPD_TMP_BUF_SIZE);
1059
1060         switch (vpd->device_identifier_code_set) {
1061         case 0x01: /* Binary */
1062                 snprintf(buf, sizeof(buf),
1063                         "T10 VPD Binary Device Identifier: %s\n",
1064                         &vpd->device_identifier[0]);
1065                 break;
1066         case 0x02: /* ASCII */
1067                 snprintf(buf, sizeof(buf),
1068                         "T10 VPD ASCII Device Identifier: %s\n",
1069                         &vpd->device_identifier[0]);
1070                 break;
1071         case 0x03: /* UTF-8 */
1072                 snprintf(buf, sizeof(buf),
1073                         "T10 VPD UTF-8 Device Identifier: %s\n",
1074                         &vpd->device_identifier[0]);
1075                 break;
1076         default:
1077                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1078                         " 0x%02x", vpd->device_identifier_code_set);
1079                 ret = -EINVAL;
1080                 break;
1081         }
1082
1083         if (p_buf)
1084                 strncpy(p_buf, buf, p_buf_len);
1085         else
1086                 pr_debug("%s", buf);
1087
1088         return ret;
1089 }
1090
1091 int
1092 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1093 {
1094         static const char hex_str[] = "0123456789abcdef";
1095         int j = 0, i = 4; /* offset to start of the identifier */
1096
1097         /*
1098          * The VPD Code Set (encoding)
1099          *
1100          * from spc3r23.pdf Section 7.6.3.1 Table 296
1101          */
1102         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1103         switch (vpd->device_identifier_code_set) {
1104         case 0x01: /* Binary */
1105                 vpd->device_identifier[j++] =
1106                                 hex_str[vpd->device_identifier_type];
1107                 while (i < (4 + page_83[3])) {
1108                         vpd->device_identifier[j++] =
1109                                 hex_str[(page_83[i] & 0xf0) >> 4];
1110                         vpd->device_identifier[j++] =
1111                                 hex_str[page_83[i] & 0x0f];
1112                         i++;
1113                 }
1114                 break;
1115         case 0x02: /* ASCII */
1116         case 0x03: /* UTF-8 */
1117                 while (i < (4 + page_83[3]))
1118                         vpd->device_identifier[j++] = page_83[i++];
1119                 break;
1120         default:
1121                 break;
1122         }
1123
1124         return transport_dump_vpd_ident(vpd, NULL, 0);
1125 }
1126 EXPORT_SYMBOL(transport_set_vpd_ident);
1127
1128 static sense_reason_t
1129 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1130                                unsigned int size)
1131 {
1132         u32 mtl;
1133
1134         if (!cmd->se_tfo->max_data_sg_nents)
1135                 return TCM_NO_SENSE;
1136         /*
1137          * Check if fabric enforced maximum SGL entries per I/O descriptor
1138          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1139          * residual_count and reduce original cmd->data_length to maximum
1140          * length based on single PAGE_SIZE entry scatter-lists.
1141          */
1142         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1143         if (cmd->data_length > mtl) {
1144                 /*
1145                  * If an existing CDB overflow is present, calculate new residual
1146                  * based on CDB size minus fabric maximum transfer length.
1147                  *
1148                  * If an existing CDB underflow is present, calculate new residual
1149                  * based on original cmd->data_length minus fabric maximum transfer
1150                  * length.
1151                  *
1152                  * Otherwise, set the underflow residual based on cmd->data_length
1153                  * minus fabric maximum transfer length.
1154                  */
1155                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1156                         cmd->residual_count = (size - mtl);
1157                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1158                         u32 orig_dl = size + cmd->residual_count;
1159                         cmd->residual_count = (orig_dl - mtl);
1160                 } else {
1161                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1162                         cmd->residual_count = (cmd->data_length - mtl);
1163                 }
1164                 cmd->data_length = mtl;
1165                 /*
1166                  * Reset sbc_check_prot() calculated protection payload
1167                  * length based upon the new smaller MTL.
1168                  */
1169                 if (cmd->prot_length) {
1170                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1171                         cmd->prot_length = dev->prot_length * sectors;
1172                 }
1173         }
1174         return TCM_NO_SENSE;
1175 }
1176
1177 sense_reason_t
1178 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1179 {
1180         struct se_device *dev = cmd->se_dev;
1181
1182         if (cmd->unknown_data_length) {
1183                 cmd->data_length = size;
1184         } else if (size != cmd->data_length) {
1185                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1186                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1187                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1188                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1189
1190                 if (cmd->data_direction == DMA_TO_DEVICE &&
1191                     cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1192                         pr_err("Rejecting underflow/overflow WRITE data\n");
1193                         return TCM_INVALID_CDB_FIELD;
1194                 }
1195                 /*
1196                  * Reject READ_* or WRITE_* with overflow/underflow for
1197                  * type SCF_SCSI_DATA_CDB.
1198                  */
1199                 if (dev->dev_attrib.block_size != 512)  {
1200                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1201                                 " CDB on non 512-byte sector setup subsystem"
1202                                 " plugin: %s\n", dev->transport->name);
1203                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1204                         return TCM_INVALID_CDB_FIELD;
1205                 }
1206                 /*
1207                  * For the overflow case keep the existing fabric provided
1208                  * ->data_length.  Otherwise for the underflow case, reset
1209                  * ->data_length to the smaller SCSI expected data transfer
1210                  * length.
1211                  */
1212                 if (size > cmd->data_length) {
1213                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1214                         cmd->residual_count = (size - cmd->data_length);
1215                 } else {
1216                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1217                         cmd->residual_count = (cmd->data_length - size);
1218                         cmd->data_length = size;
1219                 }
1220         }
1221
1222         return target_check_max_data_sg_nents(cmd, dev, size);
1223
1224 }
1225
1226 /*
1227  * Used by fabric modules containing a local struct se_cmd within their
1228  * fabric dependent per I/O descriptor.
1229  *
1230  * Preserves the value of @cmd->tag.
1231  */
1232 void transport_init_se_cmd(
1233         struct se_cmd *cmd,
1234         const struct target_core_fabric_ops *tfo,
1235         struct se_session *se_sess,
1236         u32 data_length,
1237         int data_direction,
1238         int task_attr,
1239         unsigned char *sense_buffer)
1240 {
1241         INIT_LIST_HEAD(&cmd->se_delayed_node);
1242         INIT_LIST_HEAD(&cmd->se_qf_node);
1243         INIT_LIST_HEAD(&cmd->se_cmd_list);
1244         INIT_LIST_HEAD(&cmd->state_list);
1245         init_completion(&cmd->t_transport_stop_comp);
1246         init_completion(&cmd->cmd_wait_comp);
1247         spin_lock_init(&cmd->t_state_lock);
1248         kref_init(&cmd->cmd_kref);
1249         cmd->transport_state = CMD_T_DEV_ACTIVE;
1250
1251         cmd->se_tfo = tfo;
1252         cmd->se_sess = se_sess;
1253         cmd->data_length = data_length;
1254         cmd->data_direction = data_direction;
1255         cmd->sam_task_attr = task_attr;
1256         cmd->sense_buffer = sense_buffer;
1257
1258         cmd->state_active = false;
1259 }
1260 EXPORT_SYMBOL(transport_init_se_cmd);
1261
1262 static sense_reason_t
1263 transport_check_alloc_task_attr(struct se_cmd *cmd)
1264 {
1265         struct se_device *dev = cmd->se_dev;
1266
1267         /*
1268          * Check if SAM Task Attribute emulation is enabled for this
1269          * struct se_device storage object
1270          */
1271         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1272                 return 0;
1273
1274         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1275                 pr_debug("SAM Task Attribute ACA"
1276                         " emulation is not supported\n");
1277                 return TCM_INVALID_CDB_FIELD;
1278         }
1279
1280         return 0;
1281 }
1282
1283 sense_reason_t
1284 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1285 {
1286         struct se_device *dev = cmd->se_dev;
1287         sense_reason_t ret;
1288
1289         /*
1290          * Ensure that the received CDB is less than the max (252 + 8) bytes
1291          * for VARIABLE_LENGTH_CMD
1292          */
1293         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1294                 pr_err("Received SCSI CDB with command_size: %d that"
1295                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1296                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1297                 return TCM_INVALID_CDB_FIELD;
1298         }
1299         /*
1300          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1301          * allocate the additional extended CDB buffer now..  Otherwise
1302          * setup the pointer from __t_task_cdb to t_task_cdb.
1303          */
1304         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1305                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1306                                                 GFP_KERNEL);
1307                 if (!cmd->t_task_cdb) {
1308                         pr_err("Unable to allocate cmd->t_task_cdb"
1309                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1310                                 scsi_command_size(cdb),
1311                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1312                         return TCM_OUT_OF_RESOURCES;
1313                 }
1314         } else
1315                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1316         /*
1317          * Copy the original CDB into cmd->
1318          */
1319         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1320
1321         trace_target_sequencer_start(cmd);
1322
1323         ret = dev->transport->parse_cdb(cmd);
1324         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1325                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1326                                     cmd->se_tfo->get_fabric_name(),
1327                                     cmd->se_sess->se_node_acl->initiatorname,
1328                                     cmd->t_task_cdb[0]);
1329         if (ret)
1330                 return ret;
1331
1332         ret = transport_check_alloc_task_attr(cmd);
1333         if (ret)
1334                 return ret;
1335
1336         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1337         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1338         return 0;
1339 }
1340 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1341
1342 /*
1343  * Used by fabric module frontends to queue tasks directly.
1344  * May only be used from process context.
1345  */
1346 int transport_handle_cdb_direct(
1347         struct se_cmd *cmd)
1348 {
1349         sense_reason_t ret;
1350
1351         if (!cmd->se_lun) {
1352                 dump_stack();
1353                 pr_err("cmd->se_lun is NULL\n");
1354                 return -EINVAL;
1355         }
1356         if (in_interrupt()) {
1357                 dump_stack();
1358                 pr_err("transport_generic_handle_cdb cannot be called"
1359                                 " from interrupt context\n");
1360                 return -EINVAL;
1361         }
1362         /*
1363          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1364          * outstanding descriptors are handled correctly during shutdown via
1365          * transport_wait_for_tasks()
1366          *
1367          * Also, we don't take cmd->t_state_lock here as we only expect
1368          * this to be called for initial descriptor submission.
1369          */
1370         cmd->t_state = TRANSPORT_NEW_CMD;
1371         cmd->transport_state |= CMD_T_ACTIVE;
1372
1373         /*
1374          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1375          * so follow TRANSPORT_NEW_CMD processing thread context usage
1376          * and call transport_generic_request_failure() if necessary..
1377          */
1378         ret = transport_generic_new_cmd(cmd);
1379         if (ret)
1380                 transport_generic_request_failure(cmd, ret);
1381         return 0;
1382 }
1383 EXPORT_SYMBOL(transport_handle_cdb_direct);
1384
1385 sense_reason_t
1386 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1387                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1388 {
1389         if (!sgl || !sgl_count)
1390                 return 0;
1391
1392         /*
1393          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1394          * scatterlists already have been set to follow what the fabric
1395          * passes for the original expected data transfer length.
1396          */
1397         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1398                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1399                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1400                 return TCM_INVALID_CDB_FIELD;
1401         }
1402
1403         cmd->t_data_sg = sgl;
1404         cmd->t_data_nents = sgl_count;
1405         cmd->t_bidi_data_sg = sgl_bidi;
1406         cmd->t_bidi_data_nents = sgl_bidi_count;
1407
1408         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1409         return 0;
1410 }
1411
1412 /*
1413  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1414  *                       se_cmd + use pre-allocated SGL memory.
1415  *
1416  * @se_cmd: command descriptor to submit
1417  * @se_sess: associated se_sess for endpoint
1418  * @cdb: pointer to SCSI CDB
1419  * @sense: pointer to SCSI sense buffer
1420  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1421  * @data_length: fabric expected data transfer length
1422  * @task_addr: SAM task attribute
1423  * @data_dir: DMA data direction
1424  * @flags: flags for command submission from target_sc_flags_tables
1425  * @sgl: struct scatterlist memory for unidirectional mapping
1426  * @sgl_count: scatterlist count for unidirectional mapping
1427  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1428  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1429  * @sgl_prot: struct scatterlist memory protection information
1430  * @sgl_prot_count: scatterlist count for protection information
1431  *
1432  * Task tags are supported if the caller has set @se_cmd->tag.
1433  *
1434  * Returns non zero to signal active I/O shutdown failure.  All other
1435  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1436  * but still return zero here.
1437  *
1438  * This may only be called from process context, and also currently
1439  * assumes internal allocation of fabric payload buffer by target-core.
1440  */
1441 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1442                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1443                 u32 data_length, int task_attr, int data_dir, int flags,
1444                 struct scatterlist *sgl, u32 sgl_count,
1445                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1446                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1447 {
1448         struct se_portal_group *se_tpg;
1449         sense_reason_t rc;
1450         int ret;
1451
1452         se_tpg = se_sess->se_tpg;
1453         BUG_ON(!se_tpg);
1454         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1455         BUG_ON(in_interrupt());
1456         /*
1457          * Initialize se_cmd for target operation.  From this point
1458          * exceptions are handled by sending exception status via
1459          * target_core_fabric_ops->queue_status() callback
1460          */
1461         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1462                                 data_length, data_dir, task_attr, sense);
1463
1464         if (flags & TARGET_SCF_USE_CPUID)
1465                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1466         else
1467                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1468
1469         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1470                 se_cmd->unknown_data_length = 1;
1471         /*
1472          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1473          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1474          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1475          * kref_put() to happen during fabric packet acknowledgement.
1476          */
1477         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1478         if (ret)
1479                 return ret;
1480         /*
1481          * Signal bidirectional data payloads to target-core
1482          */
1483         if (flags & TARGET_SCF_BIDI_OP)
1484                 se_cmd->se_cmd_flags |= SCF_BIDI;
1485         /*
1486          * Locate se_lun pointer and attach it to struct se_cmd
1487          */
1488         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1489         if (rc) {
1490                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1491                 target_put_sess_cmd(se_cmd);
1492                 return 0;
1493         }
1494
1495         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1496         if (rc != 0) {
1497                 transport_generic_request_failure(se_cmd, rc);
1498                 return 0;
1499         }
1500
1501         /*
1502          * Save pointers for SGLs containing protection information,
1503          * if present.
1504          */
1505         if (sgl_prot_count) {
1506                 se_cmd->t_prot_sg = sgl_prot;
1507                 se_cmd->t_prot_nents = sgl_prot_count;
1508                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1509         }
1510
1511         /*
1512          * When a non zero sgl_count has been passed perform SGL passthrough
1513          * mapping for pre-allocated fabric memory instead of having target
1514          * core perform an internal SGL allocation..
1515          */
1516         if (sgl_count != 0) {
1517                 BUG_ON(!sgl);
1518
1519                 /*
1520                  * A work-around for tcm_loop as some userspace code via
1521                  * scsi-generic do not memset their associated read buffers,
1522                  * so go ahead and do that here for type non-data CDBs.  Also
1523                  * note that this is currently guaranteed to be a single SGL
1524                  * for this case by target core in target_setup_cmd_from_cdb()
1525                  * -> transport_generic_cmd_sequencer().
1526                  */
1527                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1528                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1529                         unsigned char *buf = NULL;
1530
1531                         if (sgl)
1532                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1533
1534                         if (buf) {
1535                                 memset(buf, 0, sgl->length);
1536                                 kunmap(sg_page(sgl));
1537                         }
1538                 }
1539
1540                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1541                                 sgl_bidi, sgl_bidi_count);
1542                 if (rc != 0) {
1543                         transport_generic_request_failure(se_cmd, rc);
1544                         return 0;
1545                 }
1546         }
1547
1548         /*
1549          * Check if we need to delay processing because of ALUA
1550          * Active/NonOptimized primary access state..
1551          */
1552         core_alua_check_nonop_delay(se_cmd);
1553
1554         transport_handle_cdb_direct(se_cmd);
1555         return 0;
1556 }
1557 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1558
1559 /*
1560  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1561  *
1562  * @se_cmd: command descriptor to submit
1563  * @se_sess: associated se_sess for endpoint
1564  * @cdb: pointer to SCSI CDB
1565  * @sense: pointer to SCSI sense buffer
1566  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1567  * @data_length: fabric expected data transfer length
1568  * @task_addr: SAM task attribute
1569  * @data_dir: DMA data direction
1570  * @flags: flags for command submission from target_sc_flags_tables
1571  *
1572  * Task tags are supported if the caller has set @se_cmd->tag.
1573  *
1574  * Returns non zero to signal active I/O shutdown failure.  All other
1575  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1576  * but still return zero here.
1577  *
1578  * This may only be called from process context, and also currently
1579  * assumes internal allocation of fabric payload buffer by target-core.
1580  *
1581  * It also assumes interal target core SGL memory allocation.
1582  */
1583 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1584                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1585                 u32 data_length, int task_attr, int data_dir, int flags)
1586 {
1587         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1588                         unpacked_lun, data_length, task_attr, data_dir,
1589                         flags, NULL, 0, NULL, 0, NULL, 0);
1590 }
1591 EXPORT_SYMBOL(target_submit_cmd);
1592
1593 static void target_complete_tmr_failure(struct work_struct *work)
1594 {
1595         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1596
1597         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1598         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1599
1600         transport_cmd_check_stop_to_fabric(se_cmd);
1601 }
1602
1603 /**
1604  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1605  *                     for TMR CDBs
1606  *
1607  * @se_cmd: command descriptor to submit
1608  * @se_sess: associated se_sess for endpoint
1609  * @sense: pointer to SCSI sense buffer
1610  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1611  * @fabric_context: fabric context for TMR req
1612  * @tm_type: Type of TM request
1613  * @gfp: gfp type for caller
1614  * @tag: referenced task tag for TMR_ABORT_TASK
1615  * @flags: submit cmd flags
1616  *
1617  * Callable from all contexts.
1618  **/
1619
1620 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1621                 unsigned char *sense, u64 unpacked_lun,
1622                 void *fabric_tmr_ptr, unsigned char tm_type,
1623                 gfp_t gfp, u64 tag, int flags)
1624 {
1625         struct se_portal_group *se_tpg;
1626         int ret;
1627
1628         se_tpg = se_sess->se_tpg;
1629         BUG_ON(!se_tpg);
1630
1631         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1632                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1633         /*
1634          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1635          * allocation failure.
1636          */
1637         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1638         if (ret < 0)
1639                 return -ENOMEM;
1640
1641         if (tm_type == TMR_ABORT_TASK)
1642                 se_cmd->se_tmr_req->ref_task_tag = tag;
1643
1644         /* See target_submit_cmd for commentary */
1645         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1646         if (ret) {
1647                 core_tmr_release_req(se_cmd->se_tmr_req);
1648                 return ret;
1649         }
1650
1651         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1652         if (ret) {
1653                 /*
1654                  * For callback during failure handling, push this work off
1655                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1656                  */
1657                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1658                 schedule_work(&se_cmd->work);
1659                 return 0;
1660         }
1661         transport_generic_handle_tmr(se_cmd);
1662         return 0;
1663 }
1664 EXPORT_SYMBOL(target_submit_tmr);
1665
1666 /*
1667  * Handle SAM-esque emulation for generic transport request failures.
1668  */
1669 void transport_generic_request_failure(struct se_cmd *cmd,
1670                 sense_reason_t sense_reason)
1671 {
1672         int ret = 0, post_ret = 0;
1673
1674         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1675                 " CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1676         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1677                 cmd->se_tfo->get_cmd_state(cmd),
1678                 cmd->t_state, sense_reason);
1679         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1680                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1681                 (cmd->transport_state & CMD_T_STOP) != 0,
1682                 (cmd->transport_state & CMD_T_SENT) != 0);
1683
1684         /*
1685          * For SAM Task Attribute emulation for failed struct se_cmd
1686          */
1687         transport_complete_task_attr(cmd);
1688         /*
1689          * Handle special case for COMPARE_AND_WRITE failure, where the
1690          * callback is expected to drop the per device ->caw_sem.
1691          */
1692         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1693              cmd->transport_complete_callback)
1694                 cmd->transport_complete_callback(cmd, false, &post_ret);
1695
1696         switch (sense_reason) {
1697         case TCM_NON_EXISTENT_LUN:
1698         case TCM_UNSUPPORTED_SCSI_OPCODE:
1699         case TCM_INVALID_CDB_FIELD:
1700         case TCM_INVALID_PARAMETER_LIST:
1701         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1702         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1703         case TCM_UNKNOWN_MODE_PAGE:
1704         case TCM_WRITE_PROTECTED:
1705         case TCM_ADDRESS_OUT_OF_RANGE:
1706         case TCM_CHECK_CONDITION_ABORT_CMD:
1707         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1708         case TCM_CHECK_CONDITION_NOT_READY:
1709         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1710         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1711         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1712         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1713         case TCM_TOO_MANY_TARGET_DESCS:
1714         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1715         case TCM_TOO_MANY_SEGMENT_DESCS:
1716         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1717                 break;
1718         case TCM_OUT_OF_RESOURCES:
1719                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1720                 break;
1721         case TCM_RESERVATION_CONFLICT:
1722                 /*
1723                  * No SENSE Data payload for this case, set SCSI Status
1724                  * and queue the response to $FABRIC_MOD.
1725                  *
1726                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1727                  */
1728                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1729                 /*
1730                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1731                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1732                  * CONFLICT STATUS.
1733                  *
1734                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1735                  */
1736                 if (cmd->se_sess &&
1737                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1738                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1739                                                cmd->orig_fe_lun, 0x2C,
1740                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1741                 }
1742                 trace_target_cmd_complete(cmd);
1743                 ret = cmd->se_tfo->queue_status(cmd);
1744                 if (ret == -EAGAIN || ret == -ENOMEM)
1745                         goto queue_full;
1746                 goto check_stop;
1747         default:
1748                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1749                         cmd->t_task_cdb[0], sense_reason);
1750                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1751                 break;
1752         }
1753
1754         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1755         if (ret == -EAGAIN || ret == -ENOMEM)
1756                 goto queue_full;
1757
1758 check_stop:
1759         transport_lun_remove_cmd(cmd);
1760         transport_cmd_check_stop_to_fabric(cmd);
1761         return;
1762
1763 queue_full:
1764         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1765         transport_handle_queue_full(cmd, cmd->se_dev);
1766 }
1767 EXPORT_SYMBOL(transport_generic_request_failure);
1768
1769 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1770 {
1771         sense_reason_t ret;
1772
1773         if (!cmd->execute_cmd) {
1774                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1775                 goto err;
1776         }
1777         if (do_checks) {
1778                 /*
1779                  * Check for an existing UNIT ATTENTION condition after
1780                  * target_handle_task_attr() has done SAM task attr
1781                  * checking, and possibly have already defered execution
1782                  * out to target_restart_delayed_cmds() context.
1783                  */
1784                 ret = target_scsi3_ua_check(cmd);
1785                 if (ret)
1786                         goto err;
1787
1788                 ret = target_alua_state_check(cmd);
1789                 if (ret)
1790                         goto err;
1791
1792                 ret = target_check_reservation(cmd);
1793                 if (ret) {
1794                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1795                         goto err;
1796                 }
1797         }
1798
1799         ret = cmd->execute_cmd(cmd);
1800         if (!ret)
1801                 return;
1802 err:
1803         spin_lock_irq(&cmd->t_state_lock);
1804         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1805         spin_unlock_irq(&cmd->t_state_lock);
1806
1807         transport_generic_request_failure(cmd, ret);
1808 }
1809
1810 static int target_write_prot_action(struct se_cmd *cmd)
1811 {
1812         u32 sectors;
1813         /*
1814          * Perform WRITE_INSERT of PI using software emulation when backend
1815          * device has PI enabled, if the transport has not already generated
1816          * PI using hardware WRITE_INSERT offload.
1817          */
1818         switch (cmd->prot_op) {
1819         case TARGET_PROT_DOUT_INSERT:
1820                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1821                         sbc_dif_generate(cmd);
1822                 break;
1823         case TARGET_PROT_DOUT_STRIP:
1824                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1825                         break;
1826
1827                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1828                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1829                                              sectors, 0, cmd->t_prot_sg, 0);
1830                 if (unlikely(cmd->pi_err)) {
1831                         spin_lock_irq(&cmd->t_state_lock);
1832                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1833                         spin_unlock_irq(&cmd->t_state_lock);
1834                         transport_generic_request_failure(cmd, cmd->pi_err);
1835                         return -1;
1836                 }
1837                 break;
1838         default:
1839                 break;
1840         }
1841
1842         return 0;
1843 }
1844
1845 static bool target_handle_task_attr(struct se_cmd *cmd)
1846 {
1847         struct se_device *dev = cmd->se_dev;
1848
1849         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1850                 return false;
1851
1852         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1853
1854         /*
1855          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1856          * to allow the passed struct se_cmd list of tasks to the front of the list.
1857          */
1858         switch (cmd->sam_task_attr) {
1859         case TCM_HEAD_TAG:
1860                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1861                          cmd->t_task_cdb[0]);
1862                 return false;
1863         case TCM_ORDERED_TAG:
1864                 atomic_inc_mb(&dev->dev_ordered_sync);
1865
1866                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1867                          cmd->t_task_cdb[0]);
1868
1869                 /*
1870                  * Execute an ORDERED command if no other older commands
1871                  * exist that need to be completed first.
1872                  */
1873                 if (!atomic_read(&dev->simple_cmds))
1874                         return false;
1875                 break;
1876         default:
1877                 /*
1878                  * For SIMPLE and UNTAGGED Task Attribute commands
1879                  */
1880                 atomic_inc_mb(&dev->simple_cmds);
1881                 break;
1882         }
1883
1884         if (atomic_read(&dev->dev_ordered_sync) == 0)
1885                 return false;
1886
1887         spin_lock(&dev->delayed_cmd_lock);
1888         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1889         spin_unlock(&dev->delayed_cmd_lock);
1890
1891         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1892                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1893         return true;
1894 }
1895
1896 static int __transport_check_aborted_status(struct se_cmd *, int);
1897
1898 void target_execute_cmd(struct se_cmd *cmd)
1899 {
1900         /*
1901          * Determine if frontend context caller is requesting the stopping of
1902          * this command for frontend exceptions.
1903          *
1904          * If the received CDB has aleady been aborted stop processing it here.
1905          */
1906         spin_lock_irq(&cmd->t_state_lock);
1907         if (__transport_check_aborted_status(cmd, 1)) {
1908                 spin_unlock_irq(&cmd->t_state_lock);
1909                 return;
1910         }
1911         if (cmd->transport_state & CMD_T_STOP) {
1912                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1913                         __func__, __LINE__, cmd->tag);
1914
1915                 spin_unlock_irq(&cmd->t_state_lock);
1916                 complete_all(&cmd->t_transport_stop_comp);
1917                 return;
1918         }
1919
1920         cmd->t_state = TRANSPORT_PROCESSING;
1921         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1922         spin_unlock_irq(&cmd->t_state_lock);
1923
1924         if (target_write_prot_action(cmd))
1925                 return;
1926
1927         if (target_handle_task_attr(cmd)) {
1928                 spin_lock_irq(&cmd->t_state_lock);
1929                 cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1930                 spin_unlock_irq(&cmd->t_state_lock);
1931                 return;
1932         }
1933
1934         __target_execute_cmd(cmd, true);
1935 }
1936 EXPORT_SYMBOL(target_execute_cmd);
1937
1938 /*
1939  * Process all commands up to the last received ORDERED task attribute which
1940  * requires another blocking boundary
1941  */
1942 static void target_restart_delayed_cmds(struct se_device *dev)
1943 {
1944         for (;;) {
1945                 struct se_cmd *cmd;
1946
1947                 spin_lock(&dev->delayed_cmd_lock);
1948                 if (list_empty(&dev->delayed_cmd_list)) {
1949                         spin_unlock(&dev->delayed_cmd_lock);
1950                         break;
1951                 }
1952
1953                 cmd = list_entry(dev->delayed_cmd_list.next,
1954                                  struct se_cmd, se_delayed_node);
1955                 list_del(&cmd->se_delayed_node);
1956                 spin_unlock(&dev->delayed_cmd_lock);
1957
1958                 __target_execute_cmd(cmd, true);
1959
1960                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1961                         break;
1962         }
1963 }
1964
1965 /*
1966  * Called from I/O completion to determine which dormant/delayed
1967  * and ordered cmds need to have their tasks added to the execution queue.
1968  */
1969 static void transport_complete_task_attr(struct se_cmd *cmd)
1970 {
1971         struct se_device *dev = cmd->se_dev;
1972
1973         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1974                 return;
1975
1976         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
1977                 goto restart;
1978
1979         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1980                 atomic_dec_mb(&dev->simple_cmds);
1981                 dev->dev_cur_ordered_id++;
1982                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for SIMPLE\n",
1983                          dev->dev_cur_ordered_id);
1984         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1985                 dev->dev_cur_ordered_id++;
1986                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1987                          dev->dev_cur_ordered_id);
1988         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1989                 atomic_dec_mb(&dev->dev_ordered_sync);
1990
1991                 dev->dev_cur_ordered_id++;
1992                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1993                          dev->dev_cur_ordered_id);
1994         }
1995 restart:
1996         target_restart_delayed_cmds(dev);
1997 }
1998
1999 static void transport_complete_qf(struct se_cmd *cmd)
2000 {
2001         int ret = 0;
2002
2003         transport_complete_task_attr(cmd);
2004
2005         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2006                 trace_target_cmd_complete(cmd);
2007                 ret = cmd->se_tfo->queue_status(cmd);
2008                 goto out;
2009         }
2010
2011         switch (cmd->data_direction) {
2012         case DMA_FROM_DEVICE:
2013                 if (cmd->scsi_status)
2014                         goto queue_status;
2015
2016                 trace_target_cmd_complete(cmd);
2017                 ret = cmd->se_tfo->queue_data_in(cmd);
2018                 break;
2019         case DMA_TO_DEVICE:
2020                 if (cmd->se_cmd_flags & SCF_BIDI) {
2021                         ret = cmd->se_tfo->queue_data_in(cmd);
2022                         break;
2023                 }
2024                 /* Fall through for DMA_TO_DEVICE */
2025         case DMA_NONE:
2026 queue_status:
2027                 trace_target_cmd_complete(cmd);
2028                 ret = cmd->se_tfo->queue_status(cmd);
2029                 break;
2030         default:
2031                 break;
2032         }
2033
2034 out:
2035         if (ret < 0) {
2036                 transport_handle_queue_full(cmd, cmd->se_dev);
2037                 return;
2038         }
2039         transport_lun_remove_cmd(cmd);
2040         transport_cmd_check_stop_to_fabric(cmd);
2041 }
2042
2043 static void transport_handle_queue_full(
2044         struct se_cmd *cmd,
2045         struct se_device *dev)
2046 {
2047         spin_lock_irq(&dev->qf_cmd_lock);
2048         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2049         atomic_inc_mb(&dev->dev_qf_count);
2050         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2051
2052         schedule_work(&cmd->se_dev->qf_work_queue);
2053 }
2054
2055 static bool target_read_prot_action(struct se_cmd *cmd)
2056 {
2057         switch (cmd->prot_op) {
2058         case TARGET_PROT_DIN_STRIP:
2059                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2060                         u32 sectors = cmd->data_length >>
2061                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2062
2063                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2064                                                      sectors, 0, cmd->t_prot_sg,
2065                                                      0);
2066                         if (cmd->pi_err)
2067                                 return true;
2068                 }
2069                 break;
2070         case TARGET_PROT_DIN_INSERT:
2071                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2072                         break;
2073
2074                 sbc_dif_generate(cmd);
2075                 break;
2076         default:
2077                 break;
2078         }
2079
2080         return false;
2081 }
2082
2083 static void target_complete_ok_work(struct work_struct *work)
2084 {
2085         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2086         int ret;
2087
2088         /*
2089          * Check if we need to move delayed/dormant tasks from cmds on the
2090          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2091          * Attribute.
2092          */
2093         transport_complete_task_attr(cmd);
2094
2095         /*
2096          * Check to schedule QUEUE_FULL work, or execute an existing
2097          * cmd->transport_qf_callback()
2098          */
2099         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2100                 schedule_work(&cmd->se_dev->qf_work_queue);
2101
2102         /*
2103          * Check if we need to send a sense buffer from
2104          * the struct se_cmd in question.
2105          */
2106         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2107                 WARN_ON(!cmd->scsi_status);
2108                 ret = transport_send_check_condition_and_sense(
2109                                         cmd, 0, 1);
2110                 if (ret == -EAGAIN || ret == -ENOMEM)
2111                         goto queue_full;
2112
2113                 transport_lun_remove_cmd(cmd);
2114                 transport_cmd_check_stop_to_fabric(cmd);
2115                 return;
2116         }
2117         /*
2118          * Check for a callback, used by amongst other things
2119          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2120          */
2121         if (cmd->transport_complete_callback) {
2122                 sense_reason_t rc;
2123                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2124                 bool zero_dl = !(cmd->data_length);
2125                 int post_ret = 0;
2126
2127                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2128                 if (!rc && !post_ret) {
2129                         if (caw && zero_dl)
2130                                 goto queue_rsp;
2131
2132                         return;
2133                 } else if (rc) {
2134                         ret = transport_send_check_condition_and_sense(cmd,
2135                                                 rc, 0);
2136                         if (ret == -EAGAIN || ret == -ENOMEM)
2137                                 goto queue_full;
2138
2139                         transport_lun_remove_cmd(cmd);
2140                         transport_cmd_check_stop_to_fabric(cmd);
2141                         return;
2142                 }
2143         }
2144
2145 queue_rsp:
2146         switch (cmd->data_direction) {
2147         case DMA_FROM_DEVICE:
2148                 if (cmd->scsi_status)
2149                         goto queue_status;
2150
2151                 atomic_long_add(cmd->data_length,
2152                                 &cmd->se_lun->lun_stats.tx_data_octets);
2153                 /*
2154                  * Perform READ_STRIP of PI using software emulation when
2155                  * backend had PI enabled, if the transport will not be
2156                  * performing hardware READ_STRIP offload.
2157                  */
2158                 if (target_read_prot_action(cmd)) {
2159                         ret = transport_send_check_condition_and_sense(cmd,
2160                                                 cmd->pi_err, 0);
2161                         if (ret == -EAGAIN || ret == -ENOMEM)
2162                                 goto queue_full;
2163
2164                         transport_lun_remove_cmd(cmd);
2165                         transport_cmd_check_stop_to_fabric(cmd);
2166                         return;
2167                 }
2168
2169                 trace_target_cmd_complete(cmd);
2170                 ret = cmd->se_tfo->queue_data_in(cmd);
2171                 if (ret == -EAGAIN || ret == -ENOMEM)
2172                         goto queue_full;
2173                 break;
2174         case DMA_TO_DEVICE:
2175                 atomic_long_add(cmd->data_length,
2176                                 &cmd->se_lun->lun_stats.rx_data_octets);
2177                 /*
2178                  * Check if we need to send READ payload for BIDI-COMMAND
2179                  */
2180                 if (cmd->se_cmd_flags & SCF_BIDI) {
2181                         atomic_long_add(cmd->data_length,
2182                                         &cmd->se_lun->lun_stats.tx_data_octets);
2183                         ret = cmd->se_tfo->queue_data_in(cmd);
2184                         if (ret == -EAGAIN || ret == -ENOMEM)
2185                                 goto queue_full;
2186                         break;
2187                 }
2188                 /* Fall through for DMA_TO_DEVICE */
2189         case DMA_NONE:
2190 queue_status:
2191                 trace_target_cmd_complete(cmd);
2192                 ret = cmd->se_tfo->queue_status(cmd);
2193                 if (ret == -EAGAIN || ret == -ENOMEM)
2194                         goto queue_full;
2195                 break;
2196         default:
2197                 break;
2198         }
2199
2200         transport_lun_remove_cmd(cmd);
2201         transport_cmd_check_stop_to_fabric(cmd);
2202         return;
2203
2204 queue_full:
2205         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2206                 " data_direction: %d\n", cmd, cmd->data_direction);
2207         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2208         transport_handle_queue_full(cmd, cmd->se_dev);
2209 }
2210
2211 void target_free_sgl(struct scatterlist *sgl, int nents)
2212 {
2213         struct scatterlist *sg;
2214         int count;
2215
2216         for_each_sg(sgl, sg, nents, count)
2217                 __free_page(sg_page(sg));
2218
2219         kfree(sgl);
2220 }
2221 EXPORT_SYMBOL(target_free_sgl);
2222
2223 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2224 {
2225         /*
2226          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2227          * emulation, and free + reset pointers if necessary..
2228          */
2229         if (!cmd->t_data_sg_orig)
2230                 return;
2231
2232         kfree(cmd->t_data_sg);
2233         cmd->t_data_sg = cmd->t_data_sg_orig;
2234         cmd->t_data_sg_orig = NULL;
2235         cmd->t_data_nents = cmd->t_data_nents_orig;
2236         cmd->t_data_nents_orig = 0;
2237 }
2238
2239 static inline void transport_free_pages(struct se_cmd *cmd)
2240 {
2241         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2242                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2243                 cmd->t_prot_sg = NULL;
2244                 cmd->t_prot_nents = 0;
2245         }
2246
2247         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2248                 /*
2249                  * Release special case READ buffer payload required for
2250                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2251                  */
2252                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2253                         target_free_sgl(cmd->t_bidi_data_sg,
2254                                            cmd->t_bidi_data_nents);
2255                         cmd->t_bidi_data_sg = NULL;
2256                         cmd->t_bidi_data_nents = 0;
2257                 }
2258                 transport_reset_sgl_orig(cmd);
2259                 return;
2260         }
2261         transport_reset_sgl_orig(cmd);
2262
2263         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2264         cmd->t_data_sg = NULL;
2265         cmd->t_data_nents = 0;
2266
2267         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2268         cmd->t_bidi_data_sg = NULL;
2269         cmd->t_bidi_data_nents = 0;
2270 }
2271
2272 /**
2273  * transport_put_cmd - release a reference to a command
2274  * @cmd:       command to release
2275  *
2276  * This routine releases our reference to the command and frees it if possible.
2277  */
2278 static int transport_put_cmd(struct se_cmd *cmd)
2279 {
2280         BUG_ON(!cmd->se_tfo);
2281         /*
2282          * If this cmd has been setup with target_get_sess_cmd(), drop
2283          * the kref and call ->release_cmd() in kref callback.
2284          */
2285         return target_put_sess_cmd(cmd);
2286 }
2287
2288 void *transport_kmap_data_sg(struct se_cmd *cmd)
2289 {
2290         struct scatterlist *sg = cmd->t_data_sg;
2291         struct page **pages;
2292         int i;
2293
2294         /*
2295          * We need to take into account a possible offset here for fabrics like
2296          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2297          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2298          */
2299         if (!cmd->t_data_nents)
2300                 return NULL;
2301
2302         BUG_ON(!sg);
2303         if (cmd->t_data_nents == 1)
2304                 return kmap(sg_page(sg)) + sg->offset;
2305
2306         /* >1 page. use vmap */
2307         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2308         if (!pages)
2309                 return NULL;
2310
2311         /* convert sg[] to pages[] */
2312         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2313                 pages[i] = sg_page(sg);
2314         }
2315
2316         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2317         kfree(pages);
2318         if (!cmd->t_data_vmap)
2319                 return NULL;
2320
2321         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2322 }
2323 EXPORT_SYMBOL(transport_kmap_data_sg);
2324
2325 void transport_kunmap_data_sg(struct se_cmd *cmd)
2326 {
2327         if (!cmd->t_data_nents) {
2328                 return;
2329         } else if (cmd->t_data_nents == 1) {
2330                 kunmap(sg_page(cmd->t_data_sg));
2331                 return;
2332         }
2333
2334         vunmap(cmd->t_data_vmap);
2335         cmd->t_data_vmap = NULL;
2336 }
2337 EXPORT_SYMBOL(transport_kunmap_data_sg);
2338
2339 int
2340 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2341                  bool zero_page, bool chainable)
2342 {
2343         struct scatterlist *sg;
2344         struct page *page;
2345         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2346         unsigned int nalloc, nent;
2347         int i = 0;
2348
2349         nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2350         if (chainable)
2351                 nalloc++;
2352         sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2353         if (!sg)
2354                 return -ENOMEM;
2355
2356         sg_init_table(sg, nalloc);
2357
2358         while (length) {
2359                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2360                 page = alloc_page(GFP_KERNEL | zero_flag);
2361                 if (!page)
2362                         goto out;
2363
2364                 sg_set_page(&sg[i], page, page_len, 0);
2365                 length -= page_len;
2366                 i++;
2367         }
2368         *sgl = sg;
2369         *nents = nent;
2370         return 0;
2371
2372 out:
2373         while (i > 0) {
2374                 i--;
2375                 __free_page(sg_page(&sg[i]));
2376         }
2377         kfree(sg);
2378         return -ENOMEM;
2379 }
2380 EXPORT_SYMBOL(target_alloc_sgl);
2381
2382 /*
2383  * Allocate any required resources to execute the command.  For writes we
2384  * might not have the payload yet, so notify the fabric via a call to
2385  * ->write_pending instead. Otherwise place it on the execution queue.
2386  */
2387 sense_reason_t
2388 transport_generic_new_cmd(struct se_cmd *cmd)
2389 {
2390         int ret = 0;
2391         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2392
2393         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2394             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2395                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2396                                        cmd->prot_length, true, false);
2397                 if (ret < 0)
2398                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2399         }
2400
2401         /*
2402          * Determine is the TCM fabric module has already allocated physical
2403          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2404          * beforehand.
2405          */
2406         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2407             cmd->data_length) {
2408
2409                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2410                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2411                         u32 bidi_length;
2412
2413                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2414                                 bidi_length = cmd->t_task_nolb *
2415                                               cmd->se_dev->dev_attrib.block_size;
2416                         else
2417                                 bidi_length = cmd->data_length;
2418
2419                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2420                                                &cmd->t_bidi_data_nents,
2421                                                bidi_length, zero_flag, false);
2422                         if (ret < 0)
2423                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2424                 }
2425
2426                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2427                                        cmd->data_length, zero_flag, false);
2428                 if (ret < 0)
2429                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2430         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2431                     cmd->data_length) {
2432                 /*
2433                  * Special case for COMPARE_AND_WRITE with fabrics
2434                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2435                  */
2436                 u32 caw_length = cmd->t_task_nolb *
2437                                  cmd->se_dev->dev_attrib.block_size;
2438
2439                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2440                                        &cmd->t_bidi_data_nents,
2441                                        caw_length, zero_flag, false);
2442                 if (ret < 0)
2443                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2444         }
2445         /*
2446          * If this command is not a write we can execute it right here,
2447          * for write buffers we need to notify the fabric driver first
2448          * and let it call back once the write buffers are ready.
2449          */
2450         target_add_to_state_list(cmd);
2451         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2452                 target_execute_cmd(cmd);
2453                 return 0;
2454         }
2455         transport_cmd_check_stop(cmd, false, true);
2456
2457         ret = cmd->se_tfo->write_pending(cmd);
2458         if (ret == -EAGAIN || ret == -ENOMEM)
2459                 goto queue_full;
2460
2461         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2462         WARN_ON(ret);
2463
2464         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2465
2466 queue_full:
2467         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2468         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2469         transport_handle_queue_full(cmd, cmd->se_dev);
2470         return 0;
2471 }
2472 EXPORT_SYMBOL(transport_generic_new_cmd);
2473
2474 static void transport_write_pending_qf(struct se_cmd *cmd)
2475 {
2476         int ret;
2477
2478         ret = cmd->se_tfo->write_pending(cmd);
2479         if (ret == -EAGAIN || ret == -ENOMEM) {
2480                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2481                          cmd);
2482                 transport_handle_queue_full(cmd, cmd->se_dev);
2483         }
2484 }
2485
2486 static bool
2487 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2488                            unsigned long *flags);
2489
2490 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2491 {
2492         unsigned long flags;
2493
2494         spin_lock_irqsave(&cmd->t_state_lock, flags);
2495         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2496         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2497 }
2498
2499 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2500 {
2501         int ret = 0;
2502         bool aborted = false, tas = false;
2503
2504         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2505                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2506                         target_wait_free_cmd(cmd, &aborted, &tas);
2507
2508                 if (!aborted || tas)
2509                         ret = transport_put_cmd(cmd);
2510         } else {
2511                 if (wait_for_tasks)
2512                         target_wait_free_cmd(cmd, &aborted, &tas);
2513                 /*
2514                  * Handle WRITE failure case where transport_generic_new_cmd()
2515                  * has already added se_cmd to state_list, but fabric has
2516                  * failed command before I/O submission.
2517                  */
2518                 if (cmd->state_active)
2519                         target_remove_from_state_list(cmd);
2520
2521                 if (cmd->se_lun)
2522                         transport_lun_remove_cmd(cmd);
2523
2524                 if (!aborted || tas)
2525                         ret = transport_put_cmd(cmd);
2526         }
2527         /*
2528          * If the task has been internally aborted due to TMR ABORT_TASK
2529          * or LUN_RESET, target_core_tmr.c is responsible for performing
2530          * the remaining calls to target_put_sess_cmd(), and not the
2531          * callers of this function.
2532          */
2533         if (aborted) {
2534                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2535                 wait_for_completion(&cmd->cmd_wait_comp);
2536                 cmd->se_tfo->release_cmd(cmd);
2537                 ret = 1;
2538         }
2539         return ret;
2540 }
2541 EXPORT_SYMBOL(transport_generic_free_cmd);
2542
2543 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2544  * @se_cmd:     command descriptor to add
2545  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2546  */
2547 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2548 {
2549         struct se_session *se_sess = se_cmd->se_sess;
2550         unsigned long flags;
2551         int ret = 0;
2552
2553         /*
2554          * Add a second kref if the fabric caller is expecting to handle
2555          * fabric acknowledgement that requires two target_put_sess_cmd()
2556          * invocations before se_cmd descriptor release.
2557          */
2558         if (ack_kref) {
2559                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2560                         return -EINVAL;
2561
2562                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2563         }
2564
2565         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2566         if (se_sess->sess_tearing_down) {
2567                 ret = -ESHUTDOWN;
2568                 goto out;
2569         }
2570         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2571 out:
2572         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2573
2574         if (ret && ack_kref)
2575                 target_put_sess_cmd(se_cmd);
2576
2577         return ret;
2578 }
2579 EXPORT_SYMBOL(target_get_sess_cmd);
2580
2581 static void target_free_cmd_mem(struct se_cmd *cmd)
2582 {
2583         transport_free_pages(cmd);
2584
2585         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2586                 core_tmr_release_req(cmd->se_tmr_req);
2587         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2588                 kfree(cmd->t_task_cdb);
2589 }
2590
2591 static void target_release_cmd_kref(struct kref *kref)
2592 {
2593         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2594         struct se_session *se_sess = se_cmd->se_sess;
2595         unsigned long flags;
2596         bool fabric_stop;
2597
2598         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2599
2600         spin_lock(&se_cmd->t_state_lock);
2601         fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2602                       (se_cmd->transport_state & CMD_T_ABORTED);
2603         spin_unlock(&se_cmd->t_state_lock);
2604
2605         if (se_cmd->cmd_wait_set || fabric_stop) {
2606                 list_del_init(&se_cmd->se_cmd_list);
2607                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2608                 target_free_cmd_mem(se_cmd);
2609                 complete(&se_cmd->cmd_wait_comp);
2610                 return;
2611         }
2612         list_del_init(&se_cmd->se_cmd_list);
2613         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2614
2615         target_free_cmd_mem(se_cmd);
2616         se_cmd->se_tfo->release_cmd(se_cmd);
2617 }
2618
2619 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2620  * @se_cmd:     command descriptor to drop
2621  */
2622 int target_put_sess_cmd(struct se_cmd *se_cmd)
2623 {
2624         struct se_session *se_sess = se_cmd->se_sess;
2625
2626         if (!se_sess) {
2627                 target_free_cmd_mem(se_cmd);
2628                 se_cmd->se_tfo->release_cmd(se_cmd);
2629                 return 1;
2630         }
2631         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2632 }
2633 EXPORT_SYMBOL(target_put_sess_cmd);
2634
2635 /* target_sess_cmd_list_set_waiting - Flag all commands in
2636  *         sess_cmd_list to complete cmd_wait_comp.  Set
2637  *         sess_tearing_down so no more commands are queued.
2638  * @se_sess:    session to flag
2639  */
2640 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2641 {
2642         struct se_cmd *se_cmd, *tmp_cmd;
2643         unsigned long flags;
2644         int rc;
2645
2646         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2647         if (se_sess->sess_tearing_down) {
2648                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2649                 return;
2650         }
2651         se_sess->sess_tearing_down = 1;
2652         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2653
2654         list_for_each_entry_safe(se_cmd, tmp_cmd,
2655                                  &se_sess->sess_wait_list, se_cmd_list) {
2656                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2657                 if (rc) {
2658                         se_cmd->cmd_wait_set = 1;
2659                         spin_lock(&se_cmd->t_state_lock);
2660                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2661                         spin_unlock(&se_cmd->t_state_lock);
2662                 } else
2663                         list_del_init(&se_cmd->se_cmd_list);
2664         }
2665
2666         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2667 }
2668 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2669
2670 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2671  * @se_sess:    session to wait for active I/O
2672  */
2673 void target_wait_for_sess_cmds(struct se_session *se_sess)
2674 {
2675         struct se_cmd *se_cmd, *tmp_cmd;
2676         unsigned long flags;
2677         bool tas;
2678
2679         list_for_each_entry_safe(se_cmd, tmp_cmd,
2680                                 &se_sess->sess_wait_list, se_cmd_list) {
2681                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2682                         " %d\n", se_cmd, se_cmd->t_state,
2683                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2684
2685                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2686                 tas = (se_cmd->transport_state & CMD_T_TAS);
2687                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2688
2689                 if (!target_put_sess_cmd(se_cmd)) {
2690                         if (tas)
2691                                 target_put_sess_cmd(se_cmd);
2692                 }
2693
2694                 wait_for_completion(&se_cmd->cmd_wait_comp);
2695                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2696                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2697                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2698
2699                 se_cmd->se_tfo->release_cmd(se_cmd);
2700         }
2701
2702         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2703         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2704         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2705
2706 }
2707 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2708
2709 void transport_clear_lun_ref(struct se_lun *lun)
2710 {
2711         percpu_ref_kill(&lun->lun_ref);
2712         wait_for_completion(&lun->lun_ref_comp);
2713 }
2714
2715 static bool
2716 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2717                            bool *aborted, bool *tas, unsigned long *flags)
2718         __releases(&cmd->t_state_lock)
2719         __acquires(&cmd->t_state_lock)
2720 {
2721
2722         assert_spin_locked(&cmd->t_state_lock);
2723         WARN_ON_ONCE(!irqs_disabled());
2724
2725         if (fabric_stop)
2726                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2727
2728         if (cmd->transport_state & CMD_T_ABORTED)
2729                 *aborted = true;
2730
2731         if (cmd->transport_state & CMD_T_TAS)
2732                 *tas = true;
2733
2734         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2735             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2736                 return false;
2737
2738         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2739             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2740                 return false;
2741
2742         if (!(cmd->transport_state & CMD_T_ACTIVE))
2743                 return false;
2744
2745         if (fabric_stop && *aborted)
2746                 return false;
2747
2748         cmd->transport_state |= CMD_T_STOP;
2749
2750         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2751                  " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2752                  cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2753
2754         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2755
2756         wait_for_completion(&cmd->t_transport_stop_comp);
2757
2758         spin_lock_irqsave(&cmd->t_state_lock, *flags);
2759         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2760
2761         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2762                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2763
2764         return true;
2765 }
2766
2767 /**
2768  * transport_wait_for_tasks - wait for completion to occur
2769  * @cmd:        command to wait
2770  *
2771  * Called from frontend fabric context to wait for storage engine
2772  * to pause and/or release frontend generated struct se_cmd.
2773  */
2774 bool transport_wait_for_tasks(struct se_cmd *cmd)
2775 {
2776         unsigned long flags;
2777         bool ret, aborted = false, tas = false;
2778
2779         spin_lock_irqsave(&cmd->t_state_lock, flags);
2780         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2781         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2782
2783         return ret;
2784 }
2785 EXPORT_SYMBOL(transport_wait_for_tasks);
2786
2787 struct sense_info {
2788         u8 key;
2789         u8 asc;
2790         u8 ascq;
2791         bool add_sector_info;
2792 };
2793
2794 static const struct sense_info sense_info_table[] = {
2795         [TCM_NO_SENSE] = {
2796                 .key = NOT_READY
2797         },
2798         [TCM_NON_EXISTENT_LUN] = {
2799                 .key = ILLEGAL_REQUEST,
2800                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2801         },
2802         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
2803                 .key = ILLEGAL_REQUEST,
2804                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2805         },
2806         [TCM_SECTOR_COUNT_TOO_MANY] = {
2807                 .key = ILLEGAL_REQUEST,
2808                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2809         },
2810         [TCM_UNKNOWN_MODE_PAGE] = {
2811                 .key = ILLEGAL_REQUEST,
2812                 .asc = 0x24, /* INVALID FIELD IN CDB */
2813         },
2814         [TCM_CHECK_CONDITION_ABORT_CMD] = {
2815                 .key = ABORTED_COMMAND,
2816                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2817                 .ascq = 0x03,
2818         },
2819         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
2820                 .key = ABORTED_COMMAND,
2821                 .asc = 0x0c, /* WRITE ERROR */
2822                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2823         },
2824         [TCM_INVALID_CDB_FIELD] = {
2825                 .key = ILLEGAL_REQUEST,
2826                 .asc = 0x24, /* INVALID FIELD IN CDB */
2827         },
2828         [TCM_INVALID_PARAMETER_LIST] = {
2829                 .key = ILLEGAL_REQUEST,
2830                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2831         },
2832         [TCM_TOO_MANY_TARGET_DESCS] = {
2833                 .key = ILLEGAL_REQUEST,
2834                 .asc = 0x26,
2835                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
2836         },
2837         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
2838                 .key = ILLEGAL_REQUEST,
2839                 .asc = 0x26,
2840                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
2841         },
2842         [TCM_TOO_MANY_SEGMENT_DESCS] = {
2843                 .key = ILLEGAL_REQUEST,
2844                 .asc = 0x26,
2845                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
2846         },
2847         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
2848                 .key = ILLEGAL_REQUEST,
2849                 .asc = 0x26,
2850                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
2851         },
2852         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2853                 .key = ILLEGAL_REQUEST,
2854                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2855         },
2856         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2857                 .key = ILLEGAL_REQUEST,
2858                 .asc = 0x0c, /* WRITE ERROR */
2859                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2860         },
2861         [TCM_SERVICE_CRC_ERROR] = {
2862                 .key = ABORTED_COMMAND,
2863                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2864                 .ascq = 0x05, /* N/A */
2865         },
2866         [TCM_SNACK_REJECTED] = {
2867                 .key = ABORTED_COMMAND,
2868                 .asc = 0x11, /* READ ERROR */
2869                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2870         },
2871         [TCM_WRITE_PROTECTED] = {
2872                 .key = DATA_PROTECT,
2873                 .asc = 0x27, /* WRITE PROTECTED */
2874         },
2875         [TCM_ADDRESS_OUT_OF_RANGE] = {
2876                 .key = ILLEGAL_REQUEST,
2877                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2878         },
2879         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2880                 .key = UNIT_ATTENTION,
2881         },
2882         [TCM_CHECK_CONDITION_NOT_READY] = {
2883                 .key = NOT_READY,
2884         },
2885         [TCM_MISCOMPARE_VERIFY] = {
2886                 .key = MISCOMPARE,
2887                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2888                 .ascq = 0x00,
2889         },
2890         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2891                 .key = ABORTED_COMMAND,
2892                 .asc = 0x10,
2893                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2894                 .add_sector_info = true,
2895         },
2896         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2897                 .key = ABORTED_COMMAND,
2898                 .asc = 0x10,
2899                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2900                 .add_sector_info = true,
2901         },
2902         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2903                 .key = ABORTED_COMMAND,
2904                 .asc = 0x10,
2905                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2906                 .add_sector_info = true,
2907         },
2908         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
2909                 .key = COPY_ABORTED,
2910                 .asc = 0x0d,
2911                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
2912
2913         },
2914         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2915                 /*
2916                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2917                  * Solaris initiators.  Returning NOT READY instead means the
2918                  * operations will be retried a finite number of times and we
2919                  * can survive intermittent errors.
2920                  */
2921                 .key = NOT_READY,
2922                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2923         },
2924 };
2925
2926 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2927 {
2928         const struct sense_info *si;
2929         u8 *buffer = cmd->sense_buffer;
2930         int r = (__force int)reason;
2931         u8 asc, ascq;
2932         bool desc_format = target_sense_desc_format(cmd->se_dev);
2933
2934         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2935                 si = &sense_info_table[r];
2936         else
2937                 si = &sense_info_table[(__force int)
2938                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2939
2940         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2941                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2942                 WARN_ON_ONCE(asc == 0);
2943         } else if (si->asc == 0) {
2944                 WARN_ON_ONCE(cmd->scsi_asc == 0);
2945                 asc = cmd->scsi_asc;
2946                 ascq = cmd->scsi_ascq;
2947         } else {
2948                 asc = si->asc;
2949                 ascq = si->ascq;
2950         }
2951
2952         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2953         if (si->add_sector_info)
2954                 return scsi_set_sense_information(buffer,
2955                                                   cmd->scsi_sense_length,
2956                                                   cmd->bad_sector);
2957
2958         return 0;
2959 }
2960
2961 int
2962 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2963                 sense_reason_t reason, int from_transport)
2964 {
2965         unsigned long flags;
2966
2967         spin_lock_irqsave(&cmd->t_state_lock, flags);
2968         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2969                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2970                 return 0;
2971         }
2972         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2973         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2974
2975         if (!from_transport) {
2976                 int rc;
2977
2978                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2979                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2980                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2981                 rc = translate_sense_reason(cmd, reason);
2982                 if (rc)
2983                         return rc;
2984         }
2985
2986         trace_target_cmd_complete(cmd);
2987         return cmd->se_tfo->queue_status(cmd);
2988 }
2989 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2990
2991 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2992         __releases(&cmd->t_state_lock)
2993         __acquires(&cmd->t_state_lock)
2994 {
2995         assert_spin_locked(&cmd->t_state_lock);
2996         WARN_ON_ONCE(!irqs_disabled());
2997
2998         if (!(cmd->transport_state & CMD_T_ABORTED))
2999                 return 0;
3000         /*
3001          * If cmd has been aborted but either no status is to be sent or it has
3002          * already been sent, just return
3003          */
3004         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3005                 if (send_status)
3006                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3007                 return 1;
3008         }
3009
3010         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3011                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3012
3013         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3014         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3015         trace_target_cmd_complete(cmd);
3016
3017         spin_unlock_irq(&cmd->t_state_lock);
3018         cmd->se_tfo->queue_status(cmd);
3019         spin_lock_irq(&cmd->t_state_lock);
3020
3021         return 1;
3022 }
3023
3024 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3025 {
3026         int ret;
3027
3028         spin_lock_irq(&cmd->t_state_lock);
3029         ret = __transport_check_aborted_status(cmd, send_status);
3030         spin_unlock_irq(&cmd->t_state_lock);
3031
3032         return ret;
3033 }
3034 EXPORT_SYMBOL(transport_check_aborted_status);
3035
3036 void transport_send_task_abort(struct se_cmd *cmd)
3037 {
3038         unsigned long flags;
3039
3040         spin_lock_irqsave(&cmd->t_state_lock, flags);
3041         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3042                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3043                 return;
3044         }
3045         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3046
3047         /*
3048          * If there are still expected incoming fabric WRITEs, we wait
3049          * until until they have completed before sending a TASK_ABORTED
3050          * response.  This response with TASK_ABORTED status will be
3051          * queued back to fabric module by transport_check_aborted_status().
3052          */
3053         if (cmd->data_direction == DMA_TO_DEVICE) {
3054                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3055                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3056                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3057                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3058                                 goto send_abort;
3059                         }
3060                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3061                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3062                         return;
3063                 }
3064         }
3065 send_abort:
3066         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3067
3068         transport_lun_remove_cmd(cmd);
3069
3070         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3071                  cmd->t_task_cdb[0], cmd->tag);
3072
3073         trace_target_cmd_complete(cmd);
3074         cmd->se_tfo->queue_status(cmd);
3075 }
3076
3077 static void target_tmr_work(struct work_struct *work)
3078 {
3079         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3080         struct se_device *dev = cmd->se_dev;
3081         struct se_tmr_req *tmr = cmd->se_tmr_req;
3082         unsigned long flags;
3083         int ret;
3084
3085         spin_lock_irqsave(&cmd->t_state_lock, flags);
3086         if (cmd->transport_state & CMD_T_ABORTED) {
3087                 tmr->response = TMR_FUNCTION_REJECTED;
3088                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3089                 goto check_stop;
3090         }
3091         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3092
3093         switch (tmr->function) {
3094         case TMR_ABORT_TASK:
3095                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3096                 break;
3097         case TMR_ABORT_TASK_SET:
3098         case TMR_CLEAR_ACA:
3099         case TMR_CLEAR_TASK_SET:
3100                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3101                 break;
3102         case TMR_LUN_RESET:
3103                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3104                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3105                                          TMR_FUNCTION_REJECTED;
3106                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3107                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3108                                                cmd->orig_fe_lun, 0x29,
3109                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3110                 }
3111                 break;
3112         case TMR_TARGET_WARM_RESET:
3113                 tmr->response = TMR_FUNCTION_REJECTED;
3114                 break;
3115         case TMR_TARGET_COLD_RESET:
3116                 tmr->response = TMR_FUNCTION_REJECTED;
3117                 break;
3118         default:
3119                 pr_err("Uknown TMR function: 0x%02x.\n",
3120                                 tmr->function);
3121                 tmr->response = TMR_FUNCTION_REJECTED;
3122                 break;
3123         }
3124
3125         spin_lock_irqsave(&cmd->t_state_lock, flags);
3126         if (cmd->transport_state & CMD_T_ABORTED) {
3127                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3128                 goto check_stop;
3129         }
3130         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3131
3132         cmd->se_tfo->queue_tm_rsp(cmd);
3133
3134 check_stop:
3135         transport_cmd_check_stop_to_fabric(cmd);
3136 }
3137
3138 int transport_generic_handle_tmr(
3139         struct se_cmd *cmd)
3140 {
3141         unsigned long flags;
3142         bool aborted = false;
3143
3144         spin_lock_irqsave(&cmd->t_state_lock, flags);
3145         if (cmd->transport_state & CMD_T_ABORTED) {
3146                 aborted = true;
3147         } else {
3148                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3149                 cmd->transport_state |= CMD_T_ACTIVE;
3150         }
3151         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3152
3153         if (aborted) {
3154                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3155                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3156                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3157                 transport_cmd_check_stop_to_fabric(cmd);
3158                 return 0;
3159         }
3160
3161         INIT_WORK(&cmd->work, target_tmr_work);
3162         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3163         return 0;
3164 }
3165 EXPORT_SYMBOL(transport_generic_handle_tmr);
3166
3167 bool
3168 target_check_wce(struct se_device *dev)
3169 {
3170         bool wce = false;
3171
3172         if (dev->transport->get_write_cache)
3173                 wce = dev->transport->get_write_cache(dev);
3174         else if (dev->dev_attrib.emulate_write_cache > 0)
3175                 wce = true;
3176
3177         return wce;
3178 }
3179
3180 bool
3181 target_check_fua(struct se_device *dev)
3182 {
3183         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3184 }