drivers/target/target_core_transport.c

   1 /*******************************************************************************
   2  * Filename:  target_core_transport.c
   3  *
   4  * This file contains the Generic Target Engine Core.
   5  *
   6  * (c) Copyright 2002-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/net.h>
  27 #include <linux/delay.h>
  28 #include <linux/string.h>
  29 #include <linux/timer.h>
  30 #include <linux/slab.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/kthread.h>
  33 #include <linux/in.h>
  34 #include <linux/cdrom.h>
  35 #include <linux/module.h>
  36 #include <linux/ratelimit.h>
  37 #include <linux/vmalloc.h>
  38 #include <asm/unaligned.h>
  39 #include <net/sock.h>
  40 #include <net/tcp.h>
  41 #include <scsi/scsi_proto.h>
  42 #include <scsi/scsi_common.h>
  43
  44 #include <target/target_core_base.h>
  45 #include <target/target_core_backend.h>
  46 #include <target/target_core_fabric.h>
  47
  48 #include "target_core_internal.h"
  49 #include "target_core_alua.h"
  50 #include "target_core_pr.h"
  51 #include "target_core_ua.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/target.h>
  55
  56 static struct workqueue_struct *target_completion_wq;
  57 static struct kmem_cache *se_sess_cache;
  58 struct kmem_cache *se_ua_cache;
  59 struct kmem_cache *t10_pr_reg_cache;
  60 struct kmem_cache *t10_alua_lu_gp_cache;
  61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  63 struct kmem_cache *t10_alua_lba_map_cache;
  64 struct kmem_cache *t10_alua_lba_map_mem_cache;
  65
  66 static void transport_complete_task_attr(struct se_cmd *cmd);
  67 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
  68 static void transport_handle_queue_full(struct se_cmd *cmd,
  69                 struct se_device *dev, int err, bool write_pending);
  70 static void target_complete_ok_work(struct work_struct *work);
  71
  72 int init_se_kmem_caches(void)
  73 {
  74         se_sess_cache = kmem_cache_create("se_sess_cache",
  75                         sizeof(struct se_session), __alignof__(struct se_session),
  76                         0, NULL);
  77         if (!se_sess_cache) {
  78                 pr_err("kmem_cache_create() for struct se_session"
  79                                 " failed\n");
  80                 goto out;
  81         }
  82         se_ua_cache = kmem_cache_create("se_ua_cache",
  83                         sizeof(struct se_ua), __alignof__(struct se_ua),
  84                         0, NULL);
  85         if (!se_ua_cache) {
  86                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  87                 goto out_free_sess_cache;
  88         }
  89         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  90                         sizeof(struct t10_pr_registration),
  91                         __alignof__(struct t10_pr_registration), 0, NULL);
  92         if (!t10_pr_reg_cache) {
  93                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  94                                 " failed\n");
  95                 goto out_free_ua_cache;
  96         }
  97         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  98                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  99                         0, NULL);
 100         if (!t10_alua_lu_gp_cache) {
 101                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 102                                 " failed\n");
 103                 goto out_free_pr_reg_cache;
 104         }
 105         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 106                         sizeof(struct t10_alua_lu_gp_member),
 107                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 108         if (!t10_alua_lu_gp_mem_cache) {
 109                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 110                                 "cache failed\n");
 111                 goto out_free_lu_gp_cache;
 112         }
 113         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 114                         sizeof(struct t10_alua_tg_pt_gp),
 115                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 116         if (!t10_alua_tg_pt_gp_cache) {
 117                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 118                                 "cache failed\n");
 119                 goto out_free_lu_gp_mem_cache;
 120         }
 121         t10_alua_lba_map_cache = kmem_cache_create(
 122                         "t10_alua_lba_map_cache",
 123                         sizeof(struct t10_alua_lba_map),
 124                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 125         if (!t10_alua_lba_map_cache) {
 126                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 127                                 "cache failed\n");
 128                 goto out_free_tg_pt_gp_cache;
 129         }
 130         t10_alua_lba_map_mem_cache = kmem_cache_create(
 131                         "t10_alua_lba_map_mem_cache",
 132                         sizeof(struct t10_alua_lba_map_member),
 133                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 134         if (!t10_alua_lba_map_mem_cache) {
 135                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 136                                 "cache failed\n");
 137                 goto out_free_lba_map_cache;
 138         }
 139
 140         target_completion_wq = alloc_workqueue("target_completion",
 141                                                WQ_MEM_RECLAIM, 0);
 142         if (!target_completion_wq)
 143                 goto out_free_lba_map_mem_cache;
 144
 145         return 0;
 146
 147 out_free_lba_map_mem_cache:
 148         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 149 out_free_lba_map_cache:
 150         kmem_cache_destroy(t10_alua_lba_map_cache);
 151 out_free_tg_pt_gp_cache:
 152         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 153 out_free_lu_gp_mem_cache:
 154         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 155 out_free_lu_gp_cache:
 156         kmem_cache_destroy(t10_alua_lu_gp_cache);
 157 out_free_pr_reg_cache:
 158         kmem_cache_destroy(t10_pr_reg_cache);
 159 out_free_ua_cache:
 160         kmem_cache_destroy(se_ua_cache);
 161 out_free_sess_cache:
 162         kmem_cache_destroy(se_sess_cache);
 163 out:
 164         return -ENOMEM;
 165 }
 166
 167 void release_se_kmem_caches(void)
 168 {
 169         destroy_workqueue(target_completion_wq);
 170         kmem_cache_destroy(se_sess_cache);
 171         kmem_cache_destroy(se_ua_cache);
 172         kmem_cache_destroy(t10_pr_reg_cache);
 173         kmem_cache_destroy(t10_alua_lu_gp_cache);
 174         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 175         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 176         kmem_cache_destroy(t10_alua_lba_map_cache);
 177         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 178 }
 179
 180 /* This code ensures unique mib indexes are handed out. */
 181 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 182 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 183
 184 /*
 185  * Allocate a new row index for the entry type specified
 186  */
 187 u32 scsi_get_new_index(scsi_index_t type)
 188 {
 189         u32 new_index;
 190
 191         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 192
 193         spin_lock(&scsi_mib_index_lock);
 194         new_index = ++scsi_mib_index[type];
 195         spin_unlock(&scsi_mib_index_lock);
 196
 197         return new_index;
 198 }
 199
 200 void transport_subsystem_check_init(void)
 201 {
 202         int ret;
 203         static int sub_api_initialized;
 204
 205         if (sub_api_initialized)
 206                 return;
 207
 208         ret = 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 static void target_release_sess_cmd_refcnt(struct percpu_ref *ref)
 228 {
 229         struct se_session *sess = container_of(ref, typeof(*sess), cmd_count);
 230
 231         wake_up(&sess->cmd_list_wq);
 232 }
 233
 234 /**
 235  * transport_init_session - initialize a session object
 236  * @se_sess: Session object pointer.
 237  *
 238  * The caller must have zero-initialized @se_sess before calling this function.
 239  */
 240 int transport_init_session(struct se_session *se_sess)
 241 {
 242         INIT_LIST_HEAD(&se_sess->sess_list);
 243         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 244         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 245         spin_lock_init(&se_sess->sess_cmd_lock);
 246         init_waitqueue_head(&se_sess->cmd_list_wq);
 247         return percpu_ref_init(&se_sess->cmd_count,
 248                                target_release_sess_cmd_refcnt, 0, GFP_KERNEL);
 249 }
 250 EXPORT_SYMBOL(transport_init_session);
 251
 252 /**
 253  * transport_alloc_session - allocate a session object and initialize it
 254  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
 255  */
 256 struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
 257 {
 258         struct se_session *se_sess;
 259         int ret;
 260
 261         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 262         if (!se_sess) {
 263                 pr_err("Unable to allocate struct se_session from"
 264                                 " se_sess_cache\n");
 265                 return ERR_PTR(-ENOMEM);
 266         }
 267         ret = transport_init_session(se_sess);
 268         if (ret < 0) {
 269                 kmem_cache_free(se_sess_cache, se_sess);
 270                 return ERR_PTR(ret);
 271         }
 272         se_sess->sup_prot_ops = sup_prot_ops;
 273
 274         return se_sess;
 275 }
 276 EXPORT_SYMBOL(transport_alloc_session);
 277
 278 /**
 279  * transport_alloc_session_tags - allocate target driver private data
 280  * @se_sess:  Session pointer.
 281  * @tag_num:  Maximum number of in-flight commands between initiator and target.
 282  * @tag_size: Size in bytes of the private data a target driver associates with
 283  *            each command.
 284  */
 285 int transport_alloc_session_tags(struct se_session *se_sess,
 286                                  unsigned int tag_num, unsigned int tag_size)
 287 {
 288         int rc;
 289
 290         se_sess->sess_cmd_map = kcalloc(tag_size, tag_num,
 291                                         GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);
 292         if (!se_sess->sess_cmd_map) {
 293                 se_sess->sess_cmd_map = vzalloc(array_size(tag_size, tag_num));
 294                 if (!se_sess->sess_cmd_map) {
 295                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 296                         return -ENOMEM;
 297                 }
 298         }
 299
 300         rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
 301                         false, GFP_KERNEL, NUMA_NO_NODE);
 302         if (rc < 0) {
 303                 pr_err("Unable to init se_sess->sess_tag_pool,"
 304                         " tag_num: %u\n", tag_num);
 305                 kvfree(se_sess->sess_cmd_map);
 306                 se_sess->sess_cmd_map = NULL;
 307                 return -ENOMEM;
 308         }
 309
 310         return 0;
 311 }
 312 EXPORT_SYMBOL(transport_alloc_session_tags);
 313
 314 /**
 315  * transport_init_session_tags - allocate a session and target driver private data
 316  * @tag_num:  Maximum number of in-flight commands between initiator and target.
 317  * @tag_size: Size in bytes of the private data a target driver associates with
 318  *            each command.
 319  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
 320  */
 321 static struct se_session *
 322 transport_init_session_tags(unsigned int tag_num, unsigned int tag_size,
 323                             enum target_prot_op sup_prot_ops)
 324 {
 325         struct se_session *se_sess;
 326         int rc;
 327
 328         if (tag_num != 0 && !tag_size) {
 329                 pr_err("init_session_tags called with percpu-ida tag_num:"
 330                        " %u, but zero tag_size\n", tag_num);
 331                 return ERR_PTR(-EINVAL);
 332         }
 333         if (!tag_num && tag_size) {
 334                 pr_err("init_session_tags called with percpu-ida tag_size:"
 335                        " %u, but zero tag_num\n", tag_size);
 336                 return ERR_PTR(-EINVAL);
 337         }
 338
 339         se_sess = transport_alloc_session(sup_prot_ops);
 340         if (IS_ERR(se_sess))
 341                 return se_sess;
 342
 343         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 344         if (rc < 0) {
 345                 transport_free_session(se_sess);
 346                 return ERR_PTR(-ENOMEM);
 347         }
 348
 349         return se_sess;
 350 }
 351
 352 /*
 353  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 354  */
 355 void __transport_register_session(
 356         struct se_portal_group *se_tpg,
 357         struct se_node_acl *se_nacl,
 358         struct se_session *se_sess,
 359         void *fabric_sess_ptr)
 360 {
 361         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 362         unsigned char buf[PR_REG_ISID_LEN];
 363         unsigned long flags;
 364
 365         se_sess->se_tpg = se_tpg;
 366         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 367         /*
 368          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 369          *
 370          * Only set for struct se_session's that will actually be moving I/O.
 371          * eg: *NOT* discovery sessions.
 372          */
 373         if (se_nacl) {
 374                 /*
 375                  *
 376                  * Determine if fabric allows for T10-PI feature bits exposed to
 377                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 378                  *
 379                  * If so, then always save prot_type on a per se_node_acl node
 380                  * basis and re-instate the previous sess_prot_type to avoid
 381                  * disabling PI from below any previously initiator side
 382                  * registered LUNs.
 383                  */
 384                 if (se_nacl->saved_prot_type)
 385                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 386                 else if (tfo->tpg_check_prot_fabric_only)
 387                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 388                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 389                 /*
 390                  * If the fabric module supports an ISID based TransportID,
 391                  * save this value in binary from the fabric I_T Nexus now.
 392                  */
 393                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 394                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 395                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 396                                         &buf[0], PR_REG_ISID_LEN);
 397                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 398                 }
 399
 400                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 401                 /*
 402                  * The se_nacl->nacl_sess pointer will be set to the
 403                  * last active I_T Nexus for each struct se_node_acl.
 404                  */
 405                 se_nacl->nacl_sess = se_sess;
 406
 407                 list_add_tail(&se_sess->sess_acl_list,
 408                               &se_nacl->acl_sess_list);
 409                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 410         }
 411         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 412
 413         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 414                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 415 }
 416 EXPORT_SYMBOL(__transport_register_session);
 417
 418 void transport_register_session(
 419         struct se_portal_group *se_tpg,
 420         struct se_node_acl *se_nacl,
 421         struct se_session *se_sess,
 422         void *fabric_sess_ptr)
 423 {
 424         unsigned long flags;
 425
 426         spin_lock_irqsave(&se_tpg->session_lock, flags);
 427         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 428         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 429 }
 430 EXPORT_SYMBOL(transport_register_session);
 431
 432 struct se_session *
 433 target_setup_session(struct se_portal_group *tpg,
 434                      unsigned int tag_num, unsigned int tag_size,
 435                      enum target_prot_op prot_op,
 436                      const char *initiatorname, void *private,
 437                      int (*callback)(struct se_portal_group *,
 438                                      struct se_session *, void *))
 439 {
 440         struct se_session *sess;
 441
 442         /*
 443          * If the fabric driver is using percpu-ida based pre allocation
 444          * of I/O descriptor tags, go ahead and perform that setup now..
 445          */
 446         if (tag_num != 0)
 447                 sess = transport_init_session_tags(tag_num, tag_size, prot_op);
 448         else
 449                 sess = transport_alloc_session(prot_op);
 450
 451         if (IS_ERR(sess))
 452                 return sess;
 453
 454         sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
 455                                         (unsigned char *)initiatorname);
 456         if (!sess->se_node_acl) {
 457                 transport_free_session(sess);
 458                 return ERR_PTR(-EACCES);
 459         }
 460         /*
 461          * Go ahead and perform any remaining fabric setup that is
 462          * required before transport_register_session().
 463          */
 464         if (callback != NULL) {
 465                 int rc = callback(tpg, sess, private);
 466                 if (rc) {
 467                         transport_free_session(sess);
 468                         return ERR_PTR(rc);
 469                 }
 470         }
 471
 472         transport_register_session(tpg, sess->se_node_acl, sess, private);
 473         return sess;
 474 }
 475 EXPORT_SYMBOL(target_setup_session);
 476
 477 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 478 {
 479         struct se_session *se_sess;
 480         ssize_t len = 0;
 481
 482         spin_lock_bh(&se_tpg->session_lock);
 483         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 484                 if (!se_sess->se_node_acl)
 485                         continue;
 486                 if (!se_sess->se_node_acl->dynamic_node_acl)
 487                         continue;
 488                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 489                         break;
 490
 491                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 492                                 se_sess->se_node_acl->initiatorname);
 493                 len += 1; /* Include NULL terminator */
 494         }
 495         spin_unlock_bh(&se_tpg->session_lock);
 496
 497         return len;
 498 }
 499 EXPORT_SYMBOL(target_show_dynamic_sessions);
 500
 501 static void target_complete_nacl(struct kref *kref)
 502 {
 503         struct se_node_acl *nacl = container_of(kref,
 504                                 struct se_node_acl, acl_kref);
 505         struct se_portal_group *se_tpg = nacl->se_tpg;
 506
 507         if (!nacl->dynamic_stop) {
 508                 complete(&nacl->acl_free_comp);
 509                 return;
 510         }
 511
 512         mutex_lock(&se_tpg->acl_node_mutex);
 513         list_del_init(&nacl->acl_list);
 514         mutex_unlock(&se_tpg->acl_node_mutex);
 515
 516         core_tpg_wait_for_nacl_pr_ref(nacl);
 517         core_free_device_list_for_node(nacl, se_tpg);
 518         kfree(nacl);
 519 }
 520
 521 void target_put_nacl(struct se_node_acl *nacl)
 522 {
 523         kref_put(&nacl->acl_kref, target_complete_nacl);
 524 }
 525 EXPORT_SYMBOL(target_put_nacl);
 526
 527 void transport_deregister_session_configfs(struct se_session *se_sess)
 528 {
 529         struct se_node_acl *se_nacl;
 530         unsigned long flags;
 531         /*
 532          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 533          */
 534         se_nacl = se_sess->se_node_acl;
 535         if (se_nacl) {
 536                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 537                 if (!list_empty(&se_sess->sess_acl_list))
 538                         list_del_init(&se_sess->sess_acl_list);
 539                 /*
 540                  * If the session list is empty, then clear the pointer.
 541                  * Otherwise, set the struct se_session pointer from the tail
 542                  * element of the per struct se_node_acl active session list.
 543                  */
 544                 if (list_empty(&se_nacl->acl_sess_list))
 545                         se_nacl->nacl_sess = NULL;
 546                 else {
 547                         se_nacl->nacl_sess = container_of(
 548                                         se_nacl->acl_sess_list.prev,
 549                                         struct se_session, sess_acl_list);
 550                 }
 551                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 552         }
 553 }
 554 EXPORT_SYMBOL(transport_deregister_session_configfs);
 555
 556 void transport_free_session(struct se_session *se_sess)
 557 {
 558         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 559
 560         /*
 561          * Drop the se_node_acl->nacl_kref obtained from within
 562          * core_tpg_get_initiator_node_acl().
 563          */
 564         if (se_nacl) {
 565                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 566                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 567                 unsigned long flags;
 568
 569                 se_sess->se_node_acl = NULL;
 570
 571                 /*
 572                  * Also determine if we need to drop the extra ->cmd_kref if
 573                  * it had been previously dynamically generated, and
 574                  * the endpoint is not caching dynamic ACLs.
 575                  */
 576                 mutex_lock(&se_tpg->acl_node_mutex);
 577                 if (se_nacl->dynamic_node_acl &&
 578                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 579                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 580                         if (list_empty(&se_nacl->acl_sess_list))
 581                                 se_nacl->dynamic_stop = true;
 582                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 583
 584                         if (se_nacl->dynamic_stop)
 585                                 list_del_init(&se_nacl->acl_list);
 586                 }
 587                 mutex_unlock(&se_tpg->acl_node_mutex);
 588
 589                 if (se_nacl->dynamic_stop)
 590                         target_put_nacl(se_nacl);
 591
 592                 target_put_nacl(se_nacl);
 593         }
 594         if (se_sess->sess_cmd_map) {
 595                 sbitmap_queue_free(&se_sess->sess_tag_pool);
 596                 kvfree(se_sess->sess_cmd_map);
 597         }
 598         percpu_ref_exit(&se_sess->cmd_count);
 599         kmem_cache_free(se_sess_cache, se_sess);
 600 }
 601 EXPORT_SYMBOL(transport_free_session);
 602
 603 void transport_deregister_session(struct se_session *se_sess)
 604 {
 605         struct se_portal_group *se_tpg = se_sess->se_tpg;
 606         unsigned long flags;
 607
 608         if (!se_tpg) {
 609                 transport_free_session(se_sess);
 610                 return;
 611         }
 612
 613         spin_lock_irqsave(&se_tpg->session_lock, flags);
 614         list_del(&se_sess->sess_list);
 615         se_sess->se_tpg = NULL;
 616         se_sess->fabric_sess_ptr = NULL;
 617         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 618
 619         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 620                 se_tpg->se_tpg_tfo->get_fabric_name());
 621         /*
 622          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 623          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 624          * removal context from within transport_free_session() code.
 625          *
 626          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 627          * to release all remaining generate_node_acl=1 created ACL resources.
 628          */
 629
 630         transport_free_session(se_sess);
 631 }
 632 EXPORT_SYMBOL(transport_deregister_session);
 633
 634 void target_remove_session(struct se_session *se_sess)
 635 {
 636         transport_deregister_session_configfs(se_sess);
 637         transport_deregister_session(se_sess);
 638 }
 639 EXPORT_SYMBOL(target_remove_session);
 640
 641 static void target_remove_from_state_list(struct se_cmd *cmd)
 642 {
 643         struct se_device *dev = cmd->se_dev;
 644         unsigned long flags;
 645
 646         if (!dev)
 647                 return;
 648
 649         spin_lock_irqsave(&dev->execute_task_lock, flags);
 650         if (cmd->state_active) {
 651                 list_del(&cmd->state_list);
 652                 cmd->state_active = false;
 653         }
 654         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 655 }
 656
 657 /*
 658  * This function is called by the target core after the target core has
 659  * finished processing a SCSI command or SCSI TMF. Both the regular command
 660  * processing code and the code for aborting commands can call this
 661  * function. CMD_T_STOP is set if and only if another thread is waiting
 662  * inside transport_wait_for_tasks() for t_transport_stop_comp.
 663  */
 664 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 665 {
 666         unsigned long flags;
 667
 668         target_remove_from_state_list(cmd);
 669
 670         /*
 671          * Clear struct se_cmd->se_lun before the handoff to FE.
 672          */
 673         cmd->se_lun = NULL;
 674
 675         spin_lock_irqsave(&cmd->t_state_lock, flags);
 676         /*
 677          * Determine if frontend context caller is requesting the stopping of
 678          * this command for frontend exceptions.
 679          */
 680         if (cmd->transport_state & CMD_T_STOP) {
 681                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 682                         __func__, __LINE__, cmd->tag);
 683
 684                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 685
 686                 complete_all(&cmd->t_transport_stop_comp);
 687                 return 1;
 688         }
 689         cmd->transport_state &= ~CMD_T_ACTIVE;
 690         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 691
 692         /*
 693          * Some fabric modules like tcm_loop can release their internally
 694          * allocated I/O reference and struct se_cmd now.
 695          *
 696          * Fabric modules are expected to return '1' here if the se_cmd being
 697          * passed is released at this point, or zero if not being released.
 698          */
 699         return cmd->se_tfo->check_stop_free(cmd);
 700 }
 701
 702 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 703 {
 704         struct se_lun *lun = cmd->se_lun;
 705
 706         if (!lun)
 707                 return;
 708
 709         if (cmpxchg(&cmd->lun_ref_active, true, false))
 710                 percpu_ref_put(&lun->lun_ref);
 711 }
 712
 713 int transport_cmd_finish_abort(struct se_cmd *cmd)
 714 {
 715         bool send_tas = cmd->transport_state & CMD_T_TAS;
 716         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 717         int ret = 0;
 718
 719         if (send_tas)
 720                 transport_send_task_abort(cmd);
 721
 722         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 723                 transport_lun_remove_cmd(cmd);
 724         /*
 725          * Allow the fabric driver to unmap any resources before
 726          * releasing the descriptor via TFO->release_cmd()
 727          */
 728         if (!send_tas)
 729                 cmd->se_tfo->aborted_task(cmd);
 730
 731         if (transport_cmd_check_stop_to_fabric(cmd))
 732                 return 1;
 733         if (!send_tas && ack_kref)
 734                 ret = target_put_sess_cmd(cmd);
 735
 736         return ret;
 737 }
 738
 739 static void target_complete_failure_work(struct work_struct *work)
 740 {
 741         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 742
 743         transport_generic_request_failure(cmd,
 744                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 745 }
 746
 747 /*
 748  * Used when asking transport to copy Sense Data from the underlying
 749  * Linux/SCSI struct scsi_cmnd
 750  */
 751 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 752 {
 753         struct se_device *dev = cmd->se_dev;
 754
 755         WARN_ON(!cmd->se_lun);
 756
 757         if (!dev)
 758                 return NULL;
 759
 760         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 761                 return NULL;
 762
 763         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 764
 765         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 766                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 767         return cmd->sense_buffer;
 768 }
 769
 770 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
 771 {
 772         unsigned char *cmd_sense_buf;
 773         unsigned long flags;
 774
 775         spin_lock_irqsave(&cmd->t_state_lock, flags);
 776         cmd_sense_buf = transport_get_sense_buffer(cmd);
 777         if (!cmd_sense_buf) {
 778                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 779                 return;
 780         }
 781
 782         cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
 783         memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
 784         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 785 }
 786 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
 787
 788 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 789 {
 790         struct se_device *dev = cmd->se_dev;
 791         int success;
 792         unsigned long flags;
 793
 794         cmd->scsi_status = scsi_status;
 795
 796         spin_lock_irqsave(&cmd->t_state_lock, flags);
 797         switch (cmd->scsi_status) {
 798         case SAM_STAT_CHECK_CONDITION:
 799                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 800                         success = 1;
 801                 else
 802                         success = 0;
 803                 break;
 804         default:
 805                 success = 1;
 806                 break;
 807         }
 808
 809         /*
 810          * Check for case where an explicit ABORT_TASK has been received
 811          * and transport_wait_for_tasks() will be waiting for completion..
 812          */
 813         if (cmd->transport_state & CMD_T_ABORTED ||
 814             cmd->transport_state & CMD_T_STOP) {
 815                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 816                 /*
 817                  * If COMPARE_AND_WRITE was stopped by __transport_wait_for_tasks(),
 818                  * release se_device->caw_sem obtained by sbc_compare_and_write()
 819                  * since target_complete_ok_work() or target_complete_failure_work()
 820                  * won't be called to invoke the normal CAW completion callbacks.
 821                  */
 822                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
 823                         up(&dev->caw_sem);
 824                 }
 825                 complete_all(&cmd->t_transport_stop_comp);
 826                 return;
 827         } else if (!success) {
 828                 INIT_WORK(&cmd->work, target_complete_failure_work);
 829         } else {
 830                 INIT_WORK(&cmd->work, target_complete_ok_work);
 831         }
 832
 833         cmd->t_state = TRANSPORT_COMPLETE;
 834         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 835         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 836
 837         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 838                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 839         else
 840                 queue_work(target_completion_wq, &cmd->work);
 841 }
 842 EXPORT_SYMBOL(target_complete_cmd);
 843
 844 void target_set_cmd_data_length(struct se_cmd *cmd, int length)
 845 {
 846         if (length < cmd->data_length) {
 847                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 848                         cmd->residual_count += cmd->data_length - length;
 849                 } else {
 850                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 851                         cmd->residual_count = cmd->data_length - length;
 852                 }
 853
 854                 cmd->data_length = length;
 855         }
 856 }
 857 EXPORT_SYMBOL(target_set_cmd_data_length);
 858
 859 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 860 {
 861         if (scsi_status == SAM_STAT_GOOD ||
 862             cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) {
 863                 target_set_cmd_data_length(cmd, length);
 864         }
 865
 866         target_complete_cmd(cmd, scsi_status);
 867 }
 868 EXPORT_SYMBOL(target_complete_cmd_with_length);
 869
 870 static void target_add_to_state_list(struct se_cmd *cmd)
 871 {
 872         struct se_device *dev = cmd->se_dev;
 873         unsigned long flags;
 874
 875         spin_lock_irqsave(&dev->execute_task_lock, flags);
 876         if (!cmd->state_active) {
 877                 list_add_tail(&cmd->state_list, &dev->state_list);
 878                 cmd->state_active = true;
 879         }
 880         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 881 }
 882
 883 /*
 884  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 885  */
 886 static void transport_write_pending_qf(struct se_cmd *cmd);
 887 static void transport_complete_qf(struct se_cmd *cmd);
 888
 889 void target_qf_do_work(struct work_struct *work)
 890 {
 891         struct se_device *dev = container_of(work, struct se_device,
 892                                         qf_work_queue);
 893         LIST_HEAD(qf_cmd_list);
 894         struct se_cmd *cmd, *cmd_tmp;
 895
 896         spin_lock_irq(&dev->qf_cmd_lock);
 897         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 898         spin_unlock_irq(&dev->qf_cmd_lock);
 899
 900         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 901                 list_del(&cmd->se_qf_node);
 902                 atomic_dec_mb(&dev->dev_qf_count);
 903
 904                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 905                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 906                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 907                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 908                         : "UNKNOWN");
 909
 910                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 911                         transport_write_pending_qf(cmd);
 912                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 913                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 914                         transport_complete_qf(cmd);
 915         }
 916 }
 917
 918 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 919 {
 920         switch (cmd->data_direction) {
 921         case DMA_NONE:
 922                 return "NONE";
 923         case DMA_FROM_DEVICE:
 924                 return "READ";
 925         case DMA_TO_DEVICE:
 926                 return "WRITE";
 927         case DMA_BIDIRECTIONAL:
 928                 return "BIDI";
 929         default:
 930                 break;
 931         }
 932
 933         return "UNKNOWN";
 934 }
 935
 936 void transport_dump_dev_state(
 937         struct se_device *dev,
 938         char *b,
 939         int *bl)
 940 {
 941         *bl += sprintf(b + *bl, "Status: ");
 942         if (dev->export_count)
 943                 *bl += sprintf(b + *bl, "ACTIVATED");
 944         else
 945                 *bl += sprintf(b + *bl, "DEACTIVATED");
 946
 947         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 948         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 949                 dev->dev_attrib.block_size,
 950                 dev->dev_attrib.hw_max_sectors);
 951         *bl += sprintf(b + *bl, "        ");
 952 }
 953
 954 void transport_dump_vpd_proto_id(
 955         struct t10_vpd *vpd,
 956         unsigned char *p_buf,
 957         int p_buf_len)
 958 {
 959         unsigned char buf[VPD_TMP_BUF_SIZE];
 960         int len;
 961
 962         memset(buf, 0, VPD_TMP_BUF_SIZE);
 963         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 964
 965         switch (vpd->protocol_identifier) {
 966         case 0x00:
 967                 sprintf(buf+len, "Fibre Channel\n");
 968                 break;
 969         case 0x10:
 970                 sprintf(buf+len, "Parallel SCSI\n");
 971                 break;
 972         case 0x20:
 973                 sprintf(buf+len, "SSA\n");
 974                 break;
 975         case 0x30:
 976                 sprintf(buf+len, "IEEE 1394\n");
 977                 break;
 978         case 0x40:
 979                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 980                                 " Protocol\n");
 981                 break;
 982         case 0x50:
 983                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 984                 break;
 985         case 0x60:
 986                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 987                 break;
 988         case 0x70:
 989                 sprintf(buf+len, "Automation/Drive Interface Transport"
 990                                 " Protocol\n");
 991                 break;
 992         case 0x80:
 993                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 994                 break;
 995         default:
 996                 sprintf(buf+len, "Unknown 0x%02x\n",
 997                                 vpd->protocol_identifier);
 998                 break;
 999         }
1000
1001         if (p_buf)
1002                 strncpy(p_buf, buf, p_buf_len);
1003         else
1004                 pr_debug("%s", buf);
1005 }
1006
1007 void
1008 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
1009 {
1010         /*
1011          * Check if the Protocol Identifier Valid (PIV) bit is set..
1012          *
1013          * from spc3r23.pdf section 7.5.1
1014          */
1015          if (page_83[1] & 0x80) {
1016                 vpd->protocol_identifier = (page_83[0] & 0xf0);
1017                 vpd->protocol_identifier_set = 1;
1018                 transport_dump_vpd_proto_id(vpd, NULL, 0);
1019         }
1020 }
1021 EXPORT_SYMBOL(transport_set_vpd_proto_id);
1022
1023 int transport_dump_vpd_assoc(
1024         struct t10_vpd *vpd,
1025         unsigned char *p_buf,
1026         int p_buf_len)
1027 {
1028         unsigned char buf[VPD_TMP_BUF_SIZE];
1029         int ret = 0;
1030         int len;
1031
1032         memset(buf, 0, VPD_TMP_BUF_SIZE);
1033         len = sprintf(buf, "T10 VPD Identifier Association: ");
1034
1035         switch (vpd->association) {
1036         case 0x00:
1037                 sprintf(buf+len, "addressed logical unit\n");
1038                 break;
1039         case 0x10:
1040                 sprintf(buf+len, "target port\n");
1041                 break;
1042         case 0x20:
1043                 sprintf(buf+len, "SCSI target device\n");
1044                 break;
1045         default:
1046                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
1047                 ret = -EINVAL;
1048                 break;
1049         }
1050
1051         if (p_buf)
1052                 strncpy(p_buf, buf, p_buf_len);
1053         else
1054                 pr_debug("%s", buf);
1055
1056         return ret;
1057 }
1058
1059 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
1060 {
1061         /*
1062          * The VPD identification association..
1063          *
1064          * from spc3r23.pdf Section 7.6.3.1 Table 297
1065          */
1066         vpd->association = (page_83[1] & 0x30);
1067         return transport_dump_vpd_assoc(vpd, NULL, 0);
1068 }
1069 EXPORT_SYMBOL(transport_set_vpd_assoc);
1070
1071 int transport_dump_vpd_ident_type(
1072         struct t10_vpd *vpd,
1073         unsigned char *p_buf,
1074         int p_buf_len)
1075 {
1076         unsigned char buf[VPD_TMP_BUF_SIZE];
1077         int ret = 0;
1078         int len;
1079
1080         memset(buf, 0, VPD_TMP_BUF_SIZE);
1081         len = sprintf(buf, "T10 VPD Identifier Type: ");
1082
1083         switch (vpd->device_identifier_type) {
1084         case 0x00:
1085                 sprintf(buf+len, "Vendor specific\n");
1086                 break;
1087         case 0x01:
1088                 sprintf(buf+len, "T10 Vendor ID based\n");
1089                 break;
1090         case 0x02:
1091                 sprintf(buf+len, "EUI-64 based\n");
1092                 break;
1093         case 0x03:
1094                 sprintf(buf+len, "NAA\n");
1095                 break;
1096         case 0x04:
1097                 sprintf(buf+len, "Relative target port identifier\n");
1098                 break;
1099         case 0x08:
1100                 sprintf(buf+len, "SCSI name string\n");
1101                 break;
1102         default:
1103                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1104                                 vpd->device_identifier_type);
1105                 ret = -EINVAL;
1106                 break;
1107         }
1108
1109         if (p_buf) {
1110                 if (p_buf_len < strlen(buf)+1)
1111                         return -EINVAL;
1112                 strncpy(p_buf, buf, p_buf_len);
1113         } else {
1114                 pr_debug("%s", buf);
1115         }
1116
1117         return ret;
1118 }
1119
1120 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1121 {
1122         /*
1123          * The VPD identifier type..
1124          *
1125          * from spc3r23.pdf Section 7.6.3.1 Table 298
1126          */
1127         vpd->device_identifier_type = (page_83[1] & 0x0f);
1128         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1129 }
1130 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1131
1132 int transport_dump_vpd_ident(
1133         struct t10_vpd *vpd,
1134         unsigned char *p_buf,
1135         int p_buf_len)
1136 {
1137         unsigned char buf[VPD_TMP_BUF_SIZE];
1138         int ret = 0;
1139
1140         memset(buf, 0, VPD_TMP_BUF_SIZE);
1141
1142         switch (vpd->device_identifier_code_set) {
1143         case 0x01: /* Binary */
1144                 snprintf(buf, sizeof(buf),
1145                         "T10 VPD Binary Device Identifier: %s\n",
1146                         &vpd->device_identifier[0]);
1147                 break;
1148         case 0x02: /* ASCII */
1149                 snprintf(buf, sizeof(buf),
1150                         "T10 VPD ASCII Device Identifier: %s\n",
1151                         &vpd->device_identifier[0]);
1152                 break;
1153         case 0x03: /* UTF-8 */
1154                 snprintf(buf, sizeof(buf),
1155                         "T10 VPD UTF-8 Device Identifier: %s\n",
1156                         &vpd->device_identifier[0]);
1157                 break;
1158         default:
1159                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1160                         " 0x%02x", vpd->device_identifier_code_set);
1161                 ret = -EINVAL;
1162                 break;
1163         }
1164
1165         if (p_buf)
1166                 strncpy(p_buf, buf, p_buf_len);
1167         else
1168                 pr_debug("%s", buf);
1169
1170         return ret;
1171 }
1172
1173 int
1174 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1175 {
1176         static const char hex_str[] = "0123456789abcdef";
1177         int j = 0, i = 4; /* offset to start of the identifier */
1178
1179         /*
1180          * The VPD Code Set (encoding)
1181          *
1182          * from spc3r23.pdf Section 7.6.3.1 Table 296
1183          */
1184         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1185         switch (vpd->device_identifier_code_set) {
1186         case 0x01: /* Binary */
1187                 vpd->device_identifier[j++] =
1188                                 hex_str[vpd->device_identifier_type];
1189                 while (i < (4 + page_83[3])) {
1190                         vpd->device_identifier[j++] =
1191                                 hex_str[(page_83[i] & 0xf0) >> 4];
1192                         vpd->device_identifier[j++] =
1193                                 hex_str[page_83[i] & 0x0f];
1194                         i++;
1195                 }
1196                 break;
1197         case 0x02: /* ASCII */
1198         case 0x03: /* UTF-8 */
1199                 while (i < (4 + page_83[3]))
1200                         vpd->device_identifier[j++] = page_83[i++];
1201                 break;
1202         default:
1203                 break;
1204         }
1205
1206         return transport_dump_vpd_ident(vpd, NULL, 0);
1207 }
1208 EXPORT_SYMBOL(transport_set_vpd_ident);
1209
1210 static sense_reason_t
1211 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1212                                unsigned int size)
1213 {
1214         u32 mtl;
1215
1216         if (!cmd->se_tfo->max_data_sg_nents)
1217                 return TCM_NO_SENSE;
1218         /*
1219          * Check if fabric enforced maximum SGL entries per I/O descriptor
1220          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1221          * residual_count and reduce original cmd->data_length to maximum
1222          * length based on single PAGE_SIZE entry scatter-lists.
1223          */
1224         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1225         if (cmd->data_length > mtl) {
1226                 /*
1227                  * If an existing CDB overflow is present, calculate new residual
1228                  * based on CDB size minus fabric maximum transfer length.
1229                  *
1230                  * If an existing CDB underflow is present, calculate new residual
1231                  * based on original cmd->data_length minus fabric maximum transfer
1232                  * length.
1233                  *
1234                  * Otherwise, set the underflow residual based on cmd->data_length
1235                  * minus fabric maximum transfer length.
1236                  */
1237                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1238                         cmd->residual_count = (size - mtl);
1239                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1240                         u32 orig_dl = size + cmd->residual_count;
1241                         cmd->residual_count = (orig_dl - mtl);
1242                 } else {
1243                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1244                         cmd->residual_count = (cmd->data_length - mtl);
1245                 }
1246                 cmd->data_length = mtl;
1247                 /*
1248                  * Reset sbc_check_prot() calculated protection payload
1249                  * length based upon the new smaller MTL.
1250                  */
1251                 if (cmd->prot_length) {
1252                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1253                         cmd->prot_length = dev->prot_length * sectors;
1254                 }
1255         }
1256         return TCM_NO_SENSE;
1257 }
1258
1259 sense_reason_t
1260 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1261 {
1262         struct se_device *dev = cmd->se_dev;
1263
1264         if (cmd->unknown_data_length) {
1265                 cmd->data_length = size;
1266         } else if (size != cmd->data_length) {
1267                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1268                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1269                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1270                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1271
1272                 if (cmd->data_direction == DMA_TO_DEVICE) {
1273                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1274                                 pr_err_ratelimited("Rejecting underflow/overflow"
1275                                                    " for WRITE data CDB\n");
1276                                 return TCM_INVALID_CDB_FIELD;
1277                         }
1278                         /*
1279                          * Some fabric drivers like iscsi-target still expect to
1280                          * always reject overflow writes.  Reject this case until
1281                          * full fabric driver level support for overflow writes
1282                          * is introduced tree-wide.
1283                          */
1284                         if (size > cmd->data_length) {
1285                                 pr_err_ratelimited("Rejecting overflow for"
1286                                                    " WRITE control CDB\n");
1287                                 return TCM_INVALID_CDB_FIELD;
1288                         }
1289                 }
1290                 /*
1291                  * Reject READ_* or WRITE_* with overflow/underflow for
1292                  * type SCF_SCSI_DATA_CDB.
1293                  */
1294                 if (dev->dev_attrib.block_size != 512)  {
1295                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1296                                 " CDB on non 512-byte sector setup subsystem"
1297                                 " plugin: %s\n", dev->transport->name);
1298                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1299                         return TCM_INVALID_CDB_FIELD;
1300                 }
1301                 /*
1302                  * For the overflow case keep the existing fabric provided
1303                  * ->data_length.  Otherwise for the underflow case, reset
1304                  * ->data_length to the smaller SCSI expected data transfer
1305                  * length.
1306                  */
1307                 if (size > cmd->data_length) {
1308                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1309                         cmd->residual_count = (size - cmd->data_length);
1310                 } else {
1311                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1312                         cmd->residual_count = (cmd->data_length - size);
1313                         cmd->data_length = size;
1314                 }
1315         }
1316
1317         return target_check_max_data_sg_nents(cmd, dev, size);
1318
1319 }
1320
1321 /*
1322  * Used by fabric modules containing a local struct se_cmd within their
1323  * fabric dependent per I/O descriptor.
1324  *
1325  * Preserves the value of @cmd->tag.
1326  */
1327 void transport_init_se_cmd(
1328         struct se_cmd *cmd,
1329         const struct target_core_fabric_ops *tfo,
1330         struct se_session *se_sess,
1331         u32 data_length,
1332         int data_direction,
1333         int task_attr,
1334         unsigned char *sense_buffer)
1335 {
1336         INIT_LIST_HEAD(&cmd->se_delayed_node);
1337         INIT_LIST_HEAD(&cmd->se_qf_node);
1338         INIT_LIST_HEAD(&cmd->se_cmd_list);
1339         INIT_LIST_HEAD(&cmd->state_list);
1340         init_completion(&cmd->t_transport_stop_comp);
1341         cmd->compl = NULL;
1342         spin_lock_init(&cmd->t_state_lock);
1343         INIT_WORK(&cmd->work, NULL);
1344         kref_init(&cmd->cmd_kref);
1345
1346         cmd->se_tfo = tfo;
1347         cmd->se_sess = se_sess;
1348         cmd->data_length = data_length;
1349         cmd->data_direction = data_direction;
1350         cmd->sam_task_attr = task_attr;
1351         cmd->sense_buffer = sense_buffer;
1352
1353         cmd->state_active = false;
1354 }
1355 EXPORT_SYMBOL(transport_init_se_cmd);
1356
1357 static sense_reason_t
1358 transport_check_alloc_task_attr(struct se_cmd *cmd)
1359 {
1360         struct se_device *dev = cmd->se_dev;
1361
1362         /*
1363          * Check if SAM Task Attribute emulation is enabled for this
1364          * struct se_device storage object
1365          */
1366         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1367                 return 0;
1368
1369         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1370                 pr_debug("SAM Task Attribute ACA"
1371                         " emulation is not supported\n");
1372                 return TCM_INVALID_CDB_FIELD;
1373         }
1374
1375         return 0;
1376 }
1377
1378 sense_reason_t
1379 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1380 {
1381         struct se_device *dev = cmd->se_dev;
1382         sense_reason_t ret;
1383
1384         /*
1385          * Ensure that the received CDB is less than the max (252 + 8) bytes
1386          * for VARIABLE_LENGTH_CMD
1387          */
1388         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1389                 pr_err("Received SCSI CDB with command_size: %d that"
1390                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1391                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1392                 return TCM_INVALID_CDB_FIELD;
1393         }
1394         /*
1395          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1396          * allocate the additional extended CDB buffer now..  Otherwise
1397          * setup the pointer from __t_task_cdb to t_task_cdb.
1398          */
1399         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1400                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1401                                                 GFP_KERNEL);
1402                 if (!cmd->t_task_cdb) {
1403                         pr_err("Unable to allocate cmd->t_task_cdb"
1404                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1405                                 scsi_command_size(cdb),
1406                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1407                         return TCM_OUT_OF_RESOURCES;
1408                 }
1409         } else
1410                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1411         /*
1412          * Copy the original CDB into cmd->
1413          */
1414         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1415
1416         trace_target_sequencer_start(cmd);
1417
1418         ret = dev->transport->parse_cdb(cmd);
1419         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1420                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1421                                     cmd->se_tfo->get_fabric_name(),
1422                                     cmd->se_sess->se_node_acl->initiatorname,
1423                                     cmd->t_task_cdb[0]);
1424         if (ret)
1425                 return ret;
1426
1427         ret = transport_check_alloc_task_attr(cmd);
1428         if (ret)
1429                 return ret;
1430
1431         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1432         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1433         return 0;
1434 }
1435 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1436
1437 /*
1438  * Used by fabric module frontends to queue tasks directly.
1439  * May only be used from process context.
1440  */
1441 int transport_handle_cdb_direct(
1442         struct se_cmd *cmd)
1443 {
1444         sense_reason_t ret;
1445
1446         if (!cmd->se_lun) {
1447                 dump_stack();
1448                 pr_err("cmd->se_lun is NULL\n");
1449                 return -EINVAL;
1450         }
1451         if (in_interrupt()) {
1452                 dump_stack();
1453                 pr_err("transport_generic_handle_cdb cannot be called"
1454                                 " from interrupt context\n");
1455                 return -EINVAL;
1456         }
1457         /*
1458          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1459          * outstanding descriptors are handled correctly during shutdown via
1460          * transport_wait_for_tasks()
1461          *
1462          * Also, we don't take cmd->t_state_lock here as we only expect
1463          * this to be called for initial descriptor submission.
1464          */
1465         cmd->t_state = TRANSPORT_NEW_CMD;
1466         cmd->transport_state |= CMD_T_ACTIVE;
1467
1468         /*
1469          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1470          * so follow TRANSPORT_NEW_CMD processing thread context usage
1471          * and call transport_generic_request_failure() if necessary..
1472          */
1473         ret = transport_generic_new_cmd(cmd);
1474         if (ret)
1475                 transport_generic_request_failure(cmd, ret);
1476         return 0;
1477 }
1478 EXPORT_SYMBOL(transport_handle_cdb_direct);
1479
1480 sense_reason_t
1481 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1482                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1483 {
1484         if (!sgl || !sgl_count)
1485                 return 0;
1486
1487         /*
1488          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1489          * scatterlists already have been set to follow what the fabric
1490          * passes for the original expected data transfer length.
1491          */
1492         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1493                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1494                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1495                 return TCM_INVALID_CDB_FIELD;
1496         }
1497
1498         cmd->t_data_sg = sgl;
1499         cmd->t_data_nents = sgl_count;
1500         cmd->t_bidi_data_sg = sgl_bidi;
1501         cmd->t_bidi_data_nents = sgl_bidi_count;
1502
1503         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1504         return 0;
1505 }
1506
1507 /**
1508  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1509  *                       se_cmd + use pre-allocated SGL memory.
1510  *
1511  * @se_cmd: command descriptor to submit
1512  * @se_sess: associated se_sess for endpoint
1513  * @cdb: pointer to SCSI CDB
1514  * @sense: pointer to SCSI sense buffer
1515  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1516  * @data_length: fabric expected data transfer length
1517  * @task_attr: SAM task attribute
1518  * @data_dir: DMA data direction
1519  * @flags: flags for command submission from target_sc_flags_tables
1520  * @sgl: struct scatterlist memory for unidirectional mapping
1521  * @sgl_count: scatterlist count for unidirectional mapping
1522  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1523  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1524  * @sgl_prot: struct scatterlist memory protection information
1525  * @sgl_prot_count: scatterlist count for protection information
1526  *
1527  * Task tags are supported if the caller has set @se_cmd->tag.
1528  *
1529  * Returns non zero to signal active I/O shutdown failure.  All other
1530  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1531  * but still return zero here.
1532  *
1533  * This may only be called from process context, and also currently
1534  * assumes internal allocation of fabric payload buffer by target-core.
1535  */
1536 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1537                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1538                 u32 data_length, int task_attr, int data_dir, int flags,
1539                 struct scatterlist *sgl, u32 sgl_count,
1540                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1541                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1542 {
1543         struct se_portal_group *se_tpg;
1544         sense_reason_t rc;
1545         int ret;
1546
1547         se_tpg = se_sess->se_tpg;
1548         BUG_ON(!se_tpg);
1549         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1550         BUG_ON(in_interrupt());
1551         /*
1552          * Initialize se_cmd for target operation.  From this point
1553          * exceptions are handled by sending exception status via
1554          * target_core_fabric_ops->queue_status() callback
1555          */
1556         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1557                                 data_length, data_dir, task_attr, sense);
1558
1559         if (flags & TARGET_SCF_USE_CPUID)
1560                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1561         else
1562                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1563
1564         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1565                 se_cmd->unknown_data_length = 1;
1566         /*
1567          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1568          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1569          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1570          * kref_put() to happen during fabric packet acknowledgement.
1571          */
1572         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1573         if (ret)
1574                 return ret;
1575         /*
1576          * Signal bidirectional data payloads to target-core
1577          */
1578         if (flags & TARGET_SCF_BIDI_OP)
1579                 se_cmd->se_cmd_flags |= SCF_BIDI;
1580         /*
1581          * Locate se_lun pointer and attach it to struct se_cmd
1582          */
1583         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1584         if (rc) {
1585                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1586                 target_put_sess_cmd(se_cmd);
1587                 return 0;
1588         }
1589
1590         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1591         if (rc != 0) {
1592                 transport_generic_request_failure(se_cmd, rc);
1593                 return 0;
1594         }
1595
1596         /*
1597          * Save pointers for SGLs containing protection information,
1598          * if present.
1599          */
1600         if (sgl_prot_count) {
1601                 se_cmd->t_prot_sg = sgl_prot;
1602                 se_cmd->t_prot_nents = sgl_prot_count;
1603                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1604         }
1605
1606         /*
1607          * When a non zero sgl_count has been passed perform SGL passthrough
1608          * mapping for pre-allocated fabric memory instead of having target
1609          * core perform an internal SGL allocation..
1610          */
1611         if (sgl_count != 0) {
1612                 BUG_ON(!sgl);
1613
1614                 /*
1615                  * A work-around for tcm_loop as some userspace code via
1616                  * scsi-generic do not memset their associated read buffers,
1617                  * so go ahead and do that here for type non-data CDBs.  Also
1618                  * note that this is currently guaranteed to be a single SGL
1619                  * for this case by target core in target_setup_cmd_from_cdb()
1620                  * -> transport_generic_cmd_sequencer().
1621                  */
1622                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1623                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1624                         unsigned char *buf = NULL;
1625
1626                         if (sgl)
1627                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1628
1629                         if (buf) {
1630                                 memset(buf, 0, sgl->length);
1631                                 kunmap(sg_page(sgl));
1632                         }
1633                 }
1634
1635                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1636                                 sgl_bidi, sgl_bidi_count);
1637                 if (rc != 0) {
1638                         transport_generic_request_failure(se_cmd, rc);
1639                         return 0;
1640                 }
1641         }
1642
1643         /*
1644          * Check if we need to delay processing because of ALUA
1645          * Active/NonOptimized primary access state..
1646          */
1647         core_alua_check_nonop_delay(se_cmd);
1648
1649         transport_handle_cdb_direct(se_cmd);
1650         return 0;
1651 }
1652 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1653
1654 /**
1655  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1656  *
1657  * @se_cmd: command descriptor to submit
1658  * @se_sess: associated se_sess for endpoint
1659  * @cdb: pointer to SCSI CDB
1660  * @sense: pointer to SCSI sense buffer
1661  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1662  * @data_length: fabric expected data transfer length
1663  * @task_attr: SAM task attribute
1664  * @data_dir: DMA data direction
1665  * @flags: flags for command submission from target_sc_flags_tables
1666  *
1667  * Task tags are supported if the caller has set @se_cmd->tag.
1668  *
1669  * Returns non zero to signal active I/O shutdown failure.  All other
1670  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1671  * but still return zero here.
1672  *
1673  * This may only be called from process context, and also currently
1674  * assumes internal allocation of fabric payload buffer by target-core.
1675  *
1676  * It also assumes interal target core SGL memory allocation.
1677  */
1678 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1679                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1680                 u32 data_length, int task_attr, int data_dir, int flags)
1681 {
1682         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1683                         unpacked_lun, data_length, task_attr, data_dir,
1684                         flags, NULL, 0, NULL, 0, NULL, 0);
1685 }
1686 EXPORT_SYMBOL(target_submit_cmd);
1687
1688 static void target_complete_tmr_failure(struct work_struct *work)
1689 {
1690         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1691
1692         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1693         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1694
1695         transport_lun_remove_cmd(se_cmd);
1696         transport_cmd_check_stop_to_fabric(se_cmd);
1697 }
1698
1699 static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
1700                                        u64 *unpacked_lun)
1701 {
1702         struct se_cmd *se_cmd;
1703         unsigned long flags;
1704         bool ret = false;
1705
1706         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
1707         list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
1708                 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1709                         continue;
1710
1711                 if (se_cmd->tag == tag) {
1712                         *unpacked_lun = se_cmd->orig_fe_lun;
1713                         ret = true;
1714                         break;
1715                 }
1716         }
1717         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
1718
1719         return ret;
1720 }
1721
1722 /**
1723  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1724  *                     for TMR CDBs
1725  *
1726  * @se_cmd: command descriptor to submit
1727  * @se_sess: associated se_sess for endpoint
1728  * @sense: pointer to SCSI sense buffer
1729  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1730  * @fabric_tmr_ptr: fabric context for TMR req
1731  * @tm_type: Type of TM request
1732  * @gfp: gfp type for caller
1733  * @tag: referenced task tag for TMR_ABORT_TASK
1734  * @flags: submit cmd flags
1735  *
1736  * Callable from all contexts.
1737  **/
1738
1739 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1740                 unsigned char *sense, u64 unpacked_lun,
1741                 void *fabric_tmr_ptr, unsigned char tm_type,
1742                 gfp_t gfp, u64 tag, int flags)
1743 {
1744         struct se_portal_group *se_tpg;
1745         int ret;
1746
1747         se_tpg = se_sess->se_tpg;
1748         BUG_ON(!se_tpg);
1749
1750         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1751                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1752         /*
1753          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1754          * allocation failure.
1755          */
1756         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1757         if (ret < 0)
1758                 return -ENOMEM;
1759
1760         if (tm_type == TMR_ABORT_TASK)
1761                 se_cmd->se_tmr_req->ref_task_tag = tag;
1762
1763         /* See target_submit_cmd for commentary */
1764         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1765         if (ret) {
1766                 core_tmr_release_req(se_cmd->se_tmr_req);
1767                 return ret;
1768         }
1769         /*
1770          * If this is ABORT_TASK with no explicit fabric provided LUN,
1771          * go ahead and search active session tags for a match to figure
1772          * out unpacked_lun for the original se_cmd.
1773          */
1774         if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
1775                 if (!target_lookup_lun_from_tag(se_sess, tag, &unpacked_lun))
1776                         goto failure;
1777         }
1778
1779         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1780         if (ret)
1781                 goto failure;
1782
1783         transport_generic_handle_tmr(se_cmd);
1784         return 0;
1785
1786         /*
1787          * For callback during failure handling, push this work off
1788          * to process context with TMR_LUN_DOES_NOT_EXIST status.
1789          */
1790 failure:
1791         INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1792         schedule_work(&se_cmd->work);
1793         return 0;
1794 }
1795 EXPORT_SYMBOL(target_submit_tmr);
1796
1797 /*
1798  * Handle SAM-esque emulation for generic transport request failures.
1799  */
1800 void transport_generic_request_failure(struct se_cmd *cmd,
1801                 sense_reason_t sense_reason)
1802 {
1803         int ret = 0, post_ret = 0;
1804
1805         pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
1806                  sense_reason);
1807         target_show_cmd("-----[ ", cmd);
1808
1809         /*
1810          * For SAM Task Attribute emulation for failed struct se_cmd
1811          */
1812         transport_complete_task_attr(cmd);
1813
1814         /*
1815          * Handle special case for COMPARE_AND_WRITE failure, where the
1816          * callback is expected to drop the per device ->caw_sem.
1817          */
1818         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1819              cmd->transport_complete_callback)
1820                 cmd->transport_complete_callback(cmd, false, &post_ret);
1821
1822         if (transport_check_aborted_status(cmd, 1))
1823                 return;
1824
1825         switch (sense_reason) {
1826         case TCM_NON_EXISTENT_LUN:
1827         case TCM_UNSUPPORTED_SCSI_OPCODE:
1828         case TCM_INVALID_CDB_FIELD:
1829         case TCM_INVALID_PARAMETER_LIST:
1830         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1831         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1832         case TCM_UNKNOWN_MODE_PAGE:
1833         case TCM_WRITE_PROTECTED:
1834         case TCM_ADDRESS_OUT_OF_RANGE:
1835         case TCM_CHECK_CONDITION_ABORT_CMD:
1836         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1837         case TCM_CHECK_CONDITION_NOT_READY:
1838         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1839         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1840         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1841         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1842         case TCM_TOO_MANY_TARGET_DESCS:
1843         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1844         case TCM_TOO_MANY_SEGMENT_DESCS:
1845         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1846                 break;
1847         case TCM_OUT_OF_RESOURCES:
1848                 cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
1849                 goto queue_status;
1850         case TCM_LUN_BUSY:
1851                 cmd->scsi_status = SAM_STAT_BUSY;
1852                 goto queue_status;
1853         case TCM_RESERVATION_CONFLICT:
1854                 /*
1855                  * No SENSE Data payload for this case, set SCSI Status
1856                  * and queue the response to $FABRIC_MOD.
1857                  *
1858                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1859                  */
1860                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1861                 /*
1862                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1863                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1864                  * CONFLICT STATUS.
1865                  *
1866                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1867                  */
1868                 if (cmd->se_sess &&
1869                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1870                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1871                                                cmd->orig_fe_lun, 0x2C,
1872                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1873                 }
1874
1875                 goto queue_status;
1876         default:
1877                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1878                         cmd->t_task_cdb[0], sense_reason);
1879                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1880                 break;
1881         }
1882
1883         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1884         if (ret)
1885                 goto queue_full;
1886
1887 check_stop:
1888         transport_lun_remove_cmd(cmd);
1889         transport_cmd_check_stop_to_fabric(cmd);
1890         return;
1891
1892 queue_status:
1893         trace_target_cmd_complete(cmd);
1894         ret = cmd->se_tfo->queue_status(cmd);
1895         if (!ret)
1896                 goto check_stop;
1897 queue_full:
1898         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1899 }
1900 EXPORT_SYMBOL(transport_generic_request_failure);
1901
1902 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1903 {
1904         sense_reason_t ret;
1905
1906         if (!cmd->execute_cmd) {
1907                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1908                 goto err;
1909         }
1910         if (do_checks) {
1911                 /*
1912                  * Check for an existing UNIT ATTENTION condition after
1913                  * target_handle_task_attr() has done SAM task attr
1914                  * checking, and possibly have already defered execution
1915                  * out to target_restart_delayed_cmds() context.
1916                  */
1917                 ret = target_scsi3_ua_check(cmd);
1918                 if (ret)
1919                         goto err;
1920
1921                 ret = target_alua_state_check(cmd);
1922                 if (ret)
1923                         goto err;
1924
1925                 ret = target_check_reservation(cmd);
1926                 if (ret) {
1927                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1928                         goto err;
1929                 }
1930         }
1931
1932         ret = cmd->execute_cmd(cmd);
1933         if (!ret)
1934                 return;
1935 err:
1936         spin_lock_irq(&cmd->t_state_lock);
1937         cmd->transport_state &= ~CMD_T_SENT;
1938         spin_unlock_irq(&cmd->t_state_lock);
1939
1940         transport_generic_request_failure(cmd, ret);
1941 }
1942
1943 static int target_write_prot_action(struct se_cmd *cmd)
1944 {
1945         u32 sectors;
1946         /*
1947          * Perform WRITE_INSERT of PI using software emulation when backend
1948          * device has PI enabled, if the transport has not already generated
1949          * PI using hardware WRITE_INSERT offload.
1950          */
1951         switch (cmd->prot_op) {
1952         case TARGET_PROT_DOUT_INSERT:
1953                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1954                         sbc_dif_generate(cmd);
1955                 break;
1956         case TARGET_PROT_DOUT_STRIP:
1957                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1958                         break;
1959
1960                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1961                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1962                                              sectors, 0, cmd->t_prot_sg, 0);
1963                 if (unlikely(cmd->pi_err)) {
1964                         spin_lock_irq(&cmd->t_state_lock);
1965                         cmd->transport_state &= ~CMD_T_SENT;
1966                         spin_unlock_irq(&cmd->t_state_lock);
1967                         transport_generic_request_failure(cmd, cmd->pi_err);
1968                         return -1;
1969                 }
1970                 break;
1971         default:
1972                 break;
1973         }
1974
1975         return 0;
1976 }
1977
1978 static bool target_handle_task_attr(struct se_cmd *cmd)
1979 {
1980         struct se_device *dev = cmd->se_dev;
1981
1982         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1983                 return false;
1984
1985         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1986
1987         /*
1988          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1989          * to allow the passed struct se_cmd list of tasks to the front of the list.
1990          */
1991         switch (cmd->sam_task_attr) {
1992         case TCM_HEAD_TAG:
1993                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1994                          cmd->t_task_cdb[0]);
1995                 return false;
1996         case TCM_ORDERED_TAG:
1997                 atomic_inc_mb(&dev->dev_ordered_sync);
1998
1999                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
2000                          cmd->t_task_cdb[0]);
2001
2002                 /*
2003                  * Execute an ORDERED command if no other older commands
2004                  * exist that need to be completed first.
2005                  */
2006                 if (!atomic_read(&dev->simple_cmds))
2007                         return false;
2008                 break;
2009         default:
2010                 /*
2011                  * For SIMPLE and UNTAGGED Task Attribute commands
2012                  */
2013                 atomic_inc_mb(&dev->simple_cmds);
2014                 break;
2015         }
2016
2017         if (atomic_read(&dev->dev_ordered_sync) == 0)
2018                 return false;
2019
2020         spin_lock(&dev->delayed_cmd_lock);
2021         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
2022         spin_unlock(&dev->delayed_cmd_lock);
2023
2024         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
2025                 cmd->t_task_cdb[0], cmd->sam_task_attr);
2026         return true;
2027 }
2028
2029 static int __transport_check_aborted_status(struct se_cmd *, int);
2030
2031 void target_execute_cmd(struct se_cmd *cmd)
2032 {
2033         /*
2034          * Determine if frontend context caller is requesting the stopping of
2035          * this command for frontend exceptions.
2036          *
2037          * If the received CDB has aleady been aborted stop processing it here.
2038          */
2039         spin_lock_irq(&cmd->t_state_lock);
2040         if (__transport_check_aborted_status(cmd, 1)) {
2041                 spin_unlock_irq(&cmd->t_state_lock);
2042                 return;
2043         }
2044         if (cmd->transport_state & CMD_T_STOP) {
2045                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2046                         __func__, __LINE__, cmd->tag);
2047
2048                 spin_unlock_irq(&cmd->t_state_lock);
2049                 complete_all(&cmd->t_transport_stop_comp);
2050                 return;
2051         }
2052
2053         cmd->t_state = TRANSPORT_PROCESSING;
2054         cmd->transport_state &= ~CMD_T_PRE_EXECUTE;
2055         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
2056         spin_unlock_irq(&cmd->t_state_lock);
2057
2058         if (target_write_prot_action(cmd))
2059                 return;
2060
2061         if (target_handle_task_attr(cmd)) {
2062                 spin_lock_irq(&cmd->t_state_lock);
2063                 cmd->transport_state &= ~CMD_T_SENT;
2064                 spin_unlock_irq(&cmd->t_state_lock);
2065                 return;
2066         }
2067
2068         __target_execute_cmd(cmd, true);
2069 }
2070 EXPORT_SYMBOL(target_execute_cmd);
2071
2072 /*
2073  * Process all commands up to the last received ORDERED task attribute which
2074  * requires another blocking boundary
2075  */
2076 static void target_restart_delayed_cmds(struct se_device *dev)
2077 {
2078         for (;;) {
2079                 struct se_cmd *cmd;
2080
2081                 spin_lock(&dev->delayed_cmd_lock);
2082                 if (list_empty(&dev->delayed_cmd_list)) {
2083                         spin_unlock(&dev->delayed_cmd_lock);
2084                         break;
2085                 }
2086
2087                 cmd = list_entry(dev->delayed_cmd_list.next,
2088                                  struct se_cmd, se_delayed_node);
2089                 list_del(&cmd->se_delayed_node);
2090                 spin_unlock(&dev->delayed_cmd_lock);
2091
2092                 cmd->transport_state |= CMD_T_SENT;
2093
2094                 __target_execute_cmd(cmd, true);
2095
2096                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
2097                         break;
2098         }
2099 }
2100
2101 /*
2102  * Called from I/O completion to determine which dormant/delayed
2103  * and ordered cmds need to have their tasks added to the execution queue.
2104  */
2105 static void transport_complete_task_attr(struct se_cmd *cmd)
2106 {
2107         struct se_device *dev = cmd->se_dev;
2108
2109         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2110                 return;
2111
2112         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2113                 goto restart;
2114
2115         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2116                 atomic_dec_mb(&dev->simple_cmds);
2117                 dev->dev_cur_ordered_id++;
2118         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2119                 dev->dev_cur_ordered_id++;
2120                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2121                          dev->dev_cur_ordered_id);
2122         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2123                 atomic_dec_mb(&dev->dev_ordered_sync);
2124
2125                 dev->dev_cur_ordered_id++;
2126                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2127                          dev->dev_cur_ordered_id);
2128         }
2129         cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2130
2131 restart:
2132         target_restart_delayed_cmds(dev);
2133 }
2134
2135 static void transport_complete_qf(struct se_cmd *cmd)
2136 {
2137         int ret = 0;
2138
2139         transport_complete_task_attr(cmd);
2140         /*
2141          * If a fabric driver ->write_pending() or ->queue_data_in() callback
2142          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2143          * the same callbacks should not be retried.  Return CHECK_CONDITION
2144          * if a scsi_status is not already set.
2145          *
2146          * If a fabric driver ->queue_status() has returned non zero, always
2147          * keep retrying no matter what..
2148          */
2149         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2150                 if (cmd->scsi_status)
2151                         goto queue_status;
2152
2153                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2154                 goto queue_status;
2155         }
2156
2157         /*
2158          * Check if we need to send a sense buffer from
2159          * the struct se_cmd in question. We do NOT want
2160          * to take this path of the IO has been marked as
2161          * needing to be treated like a "normal read". This
2162          * is the case if it's a tape read, and either the
2163          * FM, EOM, or ILI bits are set, but there is no
2164          * sense data.
2165          */
2166         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2167             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2168                 goto queue_status;
2169
2170         switch (cmd->data_direction) {
2171         case DMA_FROM_DEVICE:
2172                 /* queue status if not treating this as a normal read */
2173                 if (cmd->scsi_status &&
2174                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2175                         goto queue_status;
2176
2177                 trace_target_cmd_complete(cmd);
2178                 ret = cmd->se_tfo->queue_data_in(cmd);
2179                 break;
2180         case DMA_TO_DEVICE:
2181                 if (cmd->se_cmd_flags & SCF_BIDI) {
2182                         ret = cmd->se_tfo->queue_data_in(cmd);
2183                         break;
2184                 }
2185                 /* fall through */
2186         case DMA_NONE:
2187 queue_status:
2188                 trace_target_cmd_complete(cmd);
2189                 ret = cmd->se_tfo->queue_status(cmd);
2190                 break;
2191         default:
2192                 break;
2193         }
2194
2195         if (ret < 0) {
2196                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2197                 return;
2198         }
2199         transport_lun_remove_cmd(cmd);
2200         transport_cmd_check_stop_to_fabric(cmd);
2201 }
2202
2203 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2204                                         int err, bool write_pending)
2205 {
2206         /*
2207          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2208          * ->queue_data_in() callbacks from new process context.
2209          *
2210          * Otherwise for other errors, transport_complete_qf() will send
2211          * CHECK_CONDITION via ->queue_status() instead of attempting to
2212          * retry associated fabric driver data-transfer callbacks.
2213          */
2214         if (err == -EAGAIN || err == -ENOMEM) {
2215                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2216                                                  TRANSPORT_COMPLETE_QF_OK;
2217         } else {
2218                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2219                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2220         }
2221
2222         spin_lock_irq(&dev->qf_cmd_lock);
2223         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2224         atomic_inc_mb(&dev->dev_qf_count);
2225         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2226
2227         schedule_work(&cmd->se_dev->qf_work_queue);
2228 }
2229
2230 static bool target_read_prot_action(struct se_cmd *cmd)
2231 {
2232         switch (cmd->prot_op) {
2233         case TARGET_PROT_DIN_STRIP:
2234                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2235                         u32 sectors = cmd->data_length >>
2236                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2237
2238                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2239                                                      sectors, 0, cmd->t_prot_sg,
2240                                                      0);
2241                         if (cmd->pi_err)
2242                                 return true;
2243                 }
2244                 break;
2245         case TARGET_PROT_DIN_INSERT:
2246                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2247                         break;
2248
2249                 sbc_dif_generate(cmd);
2250                 break;
2251         default:
2252                 break;
2253         }
2254
2255         return false;
2256 }
2257
2258 static void target_complete_ok_work(struct work_struct *work)
2259 {
2260         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2261         int ret;
2262
2263         /*
2264          * Check if we need to move delayed/dormant tasks from cmds on the
2265          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2266          * Attribute.
2267          */
2268         transport_complete_task_attr(cmd);
2269
2270         /*
2271          * Check to schedule QUEUE_FULL work, or execute an existing
2272          * cmd->transport_qf_callback()
2273          */
2274         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2275                 schedule_work(&cmd->se_dev->qf_work_queue);
2276
2277         /*
2278          * Check if we need to send a sense buffer from
2279          * the struct se_cmd in question. We do NOT want
2280          * to take this path of the IO has been marked as
2281          * needing to be treated like a "normal read". This
2282          * is the case if it's a tape read, and either the
2283          * FM, EOM, or ILI bits are set, but there is no
2284          * sense data.
2285          */
2286         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2287             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2288                 WARN_ON(!cmd->scsi_status);
2289                 ret = transport_send_check_condition_and_sense(
2290                                         cmd, 0, 1);
2291                 if (ret)
2292                         goto queue_full;
2293
2294                 transport_lun_remove_cmd(cmd);
2295                 transport_cmd_check_stop_to_fabric(cmd);
2296                 return;
2297         }
2298         /*
2299          * Check for a callback, used by amongst other things
2300          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2301          */
2302         if (cmd->transport_complete_callback) {
2303                 sense_reason_t rc;
2304                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2305                 bool zero_dl = !(cmd->data_length);
2306                 int post_ret = 0;
2307
2308                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2309                 if (!rc && !post_ret) {
2310                         if (caw && zero_dl)
2311                                 goto queue_rsp;
2312
2313                         return;
2314                 } else if (rc) {
2315                         ret = transport_send_check_condition_and_sense(cmd,
2316                                                 rc, 0);
2317                         if (ret)
2318                                 goto queue_full;
2319
2320                         transport_lun_remove_cmd(cmd);
2321                         transport_cmd_check_stop_to_fabric(cmd);
2322                         return;
2323                 }
2324         }
2325
2326 queue_rsp:
2327         switch (cmd->data_direction) {
2328         case DMA_FROM_DEVICE:
2329                 /*
2330                  * if this is a READ-type IO, but SCSI status
2331                  * is set, then skip returning data and just
2332                  * return the status -- unless this IO is marked
2333                  * as needing to be treated as a normal read,
2334                  * in which case we want to go ahead and return
2335                  * the data. This happens, for example, for tape
2336                  * reads with the FM, EOM, or ILI bits set, with
2337                  * no sense data.
2338                  */
2339                 if (cmd->scsi_status &&
2340                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2341                         goto queue_status;
2342
2343                 atomic_long_add(cmd->data_length,
2344                                 &cmd->se_lun->lun_stats.tx_data_octets);
2345                 /*
2346                  * Perform READ_STRIP of PI using software emulation when
2347                  * backend had PI enabled, if the transport will not be
2348                  * performing hardware READ_STRIP offload.
2349                  */
2350                 if (target_read_prot_action(cmd)) {
2351                         ret = transport_send_check_condition_and_sense(cmd,
2352                                                 cmd->pi_err, 0);
2353                         if (ret)
2354                                 goto queue_full;
2355
2356                         transport_lun_remove_cmd(cmd);
2357                         transport_cmd_check_stop_to_fabric(cmd);
2358                         return;
2359                 }
2360
2361                 trace_target_cmd_complete(cmd);
2362                 ret = cmd->se_tfo->queue_data_in(cmd);
2363                 if (ret)
2364                         goto queue_full;
2365                 break;
2366         case DMA_TO_DEVICE:
2367                 atomic_long_add(cmd->data_length,
2368                                 &cmd->se_lun->lun_stats.rx_data_octets);
2369                 /*
2370                  * Check if we need to send READ payload for BIDI-COMMAND
2371                  */
2372                 if (cmd->se_cmd_flags & SCF_BIDI) {
2373                         atomic_long_add(cmd->data_length,
2374                                         &cmd->se_lun->lun_stats.tx_data_octets);
2375                         ret = cmd->se_tfo->queue_data_in(cmd);
2376                         if (ret)
2377                                 goto queue_full;
2378                         break;
2379                 }
2380                 /* fall through */
2381         case DMA_NONE:
2382 queue_status:
2383                 trace_target_cmd_complete(cmd);
2384                 ret = cmd->se_tfo->queue_status(cmd);
2385                 if (ret)
2386                         goto queue_full;
2387                 break;
2388         default:
2389                 break;
2390         }
2391
2392         transport_lun_remove_cmd(cmd);
2393         transport_cmd_check_stop_to_fabric(cmd);
2394         return;
2395
2396 queue_full:
2397         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2398                 " data_direction: %d\n", cmd, cmd->data_direction);
2399
2400         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2401 }
2402
2403 void target_free_sgl(struct scatterlist *sgl, int nents)
2404 {
2405         sgl_free_n_order(sgl, nents, 0);
2406 }
2407 EXPORT_SYMBOL(target_free_sgl);
2408
2409 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2410 {
2411         /*
2412          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2413          * emulation, and free + reset pointers if necessary..
2414          */
2415         if (!cmd->t_data_sg_orig)
2416                 return;
2417
2418         kfree(cmd->t_data_sg);
2419         cmd->t_data_sg = cmd->t_data_sg_orig;
2420         cmd->t_data_sg_orig = NULL;
2421         cmd->t_data_nents = cmd->t_data_nents_orig;
2422         cmd->t_data_nents_orig = 0;
2423 }
2424
2425 static inline void transport_free_pages(struct se_cmd *cmd)
2426 {
2427         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2428                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2429                 cmd->t_prot_sg = NULL;
2430                 cmd->t_prot_nents = 0;
2431         }
2432
2433         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2434                 /*
2435                  * Release special case READ buffer payload required for
2436                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2437                  */
2438                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2439                         target_free_sgl(cmd->t_bidi_data_sg,
2440                                            cmd->t_bidi_data_nents);
2441                         cmd->t_bidi_data_sg = NULL;
2442                         cmd->t_bidi_data_nents = 0;
2443                 }
2444                 transport_reset_sgl_orig(cmd);
2445                 return;
2446         }
2447         transport_reset_sgl_orig(cmd);
2448
2449         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2450         cmd->t_data_sg = NULL;
2451         cmd->t_data_nents = 0;
2452
2453         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2454         cmd->t_bidi_data_sg = NULL;
2455         cmd->t_bidi_data_nents = 0;
2456 }
2457
2458 void *transport_kmap_data_sg(struct se_cmd *cmd)
2459 {
2460         struct scatterlist *sg = cmd->t_data_sg;
2461         struct page **pages;
2462         int i;
2463
2464         /*
2465          * We need to take into account a possible offset here for fabrics like
2466          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2467          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2468          */
2469         if (!cmd->t_data_nents)
2470                 return NULL;
2471
2472         BUG_ON(!sg);
2473         if (cmd->t_data_nents == 1)
2474                 return kmap(sg_page(sg)) + sg->offset;
2475
2476         /* >1 page. use vmap */
2477         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2478         if (!pages)
2479                 return NULL;
2480
2481         /* convert sg[] to pages[] */
2482         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2483                 pages[i] = sg_page(sg);
2484         }
2485
2486         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2487         kfree(pages);
2488         if (!cmd->t_data_vmap)
2489                 return NULL;
2490
2491         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2492 }
2493 EXPORT_SYMBOL(transport_kmap_data_sg);
2494
2495 void transport_kunmap_data_sg(struct se_cmd *cmd)
2496 {
2497         if (!cmd->t_data_nents) {
2498                 return;
2499         } else if (cmd->t_data_nents == 1) {
2500                 kunmap(sg_page(cmd->t_data_sg));
2501                 return;
2502         }
2503
2504         vunmap(cmd->t_data_vmap);
2505         cmd->t_data_vmap = NULL;
2506 }
2507 EXPORT_SYMBOL(transport_kunmap_data_sg);
2508
2509 int
2510 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2511                  bool zero_page, bool chainable)
2512 {
2513         gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
2514
2515         *sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
2516         return *sgl ? 0 : -ENOMEM;
2517 }
2518 EXPORT_SYMBOL(target_alloc_sgl);
2519
2520 /*
2521  * Allocate any required resources to execute the command.  For writes we
2522  * might not have the payload yet, so notify the fabric via a call to
2523  * ->write_pending instead. Otherwise place it on the execution queue.
2524  */
2525 sense_reason_t
2526 transport_generic_new_cmd(struct se_cmd *cmd)
2527 {
2528         unsigned long flags;
2529         int ret = 0;
2530         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2531
2532         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2533             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2534                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2535                                        cmd->prot_length, true, false);
2536                 if (ret < 0)
2537                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2538         }
2539
2540         /*
2541          * Determine is the TCM fabric module has already allocated physical
2542          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2543          * beforehand.
2544          */
2545         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2546             cmd->data_length) {
2547
2548                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2549                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2550                         u32 bidi_length;
2551
2552                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2553                                 bidi_length = cmd->t_task_nolb *
2554                                               cmd->se_dev->dev_attrib.block_size;
2555                         else
2556                                 bidi_length = cmd->data_length;
2557
2558                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2559                                                &cmd->t_bidi_data_nents,
2560                                                bidi_length, zero_flag, false);
2561                         if (ret < 0)
2562                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2563                 }
2564
2565                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2566                                        cmd->data_length, zero_flag, false);
2567                 if (ret < 0)
2568                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2569         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2570                     cmd->data_length) {
2571                 /*
2572                  * Special case for COMPARE_AND_WRITE with fabrics
2573                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2574                  */
2575                 u32 caw_length = cmd->t_task_nolb *
2576                                  cmd->se_dev->dev_attrib.block_size;
2577
2578                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2579                                        &cmd->t_bidi_data_nents,
2580                                        caw_length, zero_flag, false);
2581                 if (ret < 0)
2582                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2583         }
2584         /*
2585          * If this command is not a write we can execute it right here,
2586          * for write buffers we need to notify the fabric driver first
2587          * and let it call back once the write buffers are ready.
2588          */
2589         target_add_to_state_list(cmd);
2590         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2591                 target_execute_cmd(cmd);
2592                 return 0;
2593         }
2594
2595         spin_lock_irqsave(&cmd->t_state_lock, flags);
2596         cmd->t_state = TRANSPORT_WRITE_PENDING;
2597         /*
2598          * Determine if frontend context caller is requesting the stopping of
2599          * this command for frontend exceptions.
2600          */
2601         if (cmd->transport_state & CMD_T_STOP) {
2602                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2603                          __func__, __LINE__, cmd->tag);
2604
2605                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2606
2607                 complete_all(&cmd->t_transport_stop_comp);
2608                 return 0;
2609         }
2610         cmd->transport_state &= ~CMD_T_ACTIVE;
2611         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2612
2613         ret = cmd->se_tfo->write_pending(cmd);
2614         if (ret)
2615                 goto queue_full;
2616
2617         return 0;
2618
2619 queue_full:
2620         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2621         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2622         return 0;
2623 }
2624 EXPORT_SYMBOL(transport_generic_new_cmd);
2625
2626 static void transport_write_pending_qf(struct se_cmd *cmd)
2627 {
2628         unsigned long flags;
2629         int ret;
2630         bool stop;
2631
2632         spin_lock_irqsave(&cmd->t_state_lock, flags);
2633         stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2634         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2635
2636         if (stop) {
2637                 pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2638                         __func__, __LINE__, cmd->tag);
2639                 complete_all(&cmd->t_transport_stop_comp);
2640                 return;
2641         }
2642
2643         ret = cmd->se_tfo->write_pending(cmd);
2644         if (ret) {
2645                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2646                          cmd);
2647                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2648         }
2649 }
2650
2651 static bool
2652 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2653                            unsigned long *flags);
2654
2655 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2656 {
2657         unsigned long flags;
2658
2659         spin_lock_irqsave(&cmd->t_state_lock, flags);
2660         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2661         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2662 }
2663
2664 /*
2665  * This function is called by frontend drivers after processing of a command
2666  * has finished.
2667  *
2668  * The protocol for ensuring that either the regular flow or the TMF
2669  * code drops one reference is as follows:
2670  * - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
2671  *   the frontend driver to drop one reference, synchronously or asynchronously.
2672  * - During regular command processing the target core sets CMD_T_COMPLETE
2673  *   before invoking one of the .queue_*() functions.
2674  * - The code that aborts commands skips commands and TMFs for which
2675  *   CMD_T_COMPLETE has been set.
2676  * - CMD_T_ABORTED is set atomically after the CMD_T_COMPLETE check for
2677  *   commands that will be aborted.
2678  * - If the CMD_T_ABORTED flag is set but CMD_T_TAS has not been set
2679  *   transport_generic_free_cmd() skips its call to target_put_sess_cmd().
2680  * - For aborted commands for which CMD_T_TAS has been set .queue_status() will
2681  *   be called and will drop a reference.
2682  * - For aborted commands for which CMD_T_TAS has not been set .aborted_task()
2683  *   will be called. transport_cmd_finish_abort() will drop the final reference.
2684  */
2685 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2686 {
2687         DECLARE_COMPLETION_ONSTACK(compl);
2688         int ret = 0;
2689         bool aborted = false, tas = false;
2690
2691         if (wait_for_tasks)
2692                 target_wait_free_cmd(cmd, &aborted, &tas);
2693
2694         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD) {
2695                 /*
2696                  * Handle WRITE failure case where transport_generic_new_cmd()
2697                  * has already added se_cmd to state_list, but fabric has
2698                  * failed command before I/O submission.
2699                  */
2700                 if (cmd->state_active)
2701                         target_remove_from_state_list(cmd);
2702
2703                 if (cmd->se_lun)
2704                         transport_lun_remove_cmd(cmd);
2705         }
2706         if (aborted)
2707                 cmd->compl = &compl;
2708         if (!aborted || tas)
2709                 ret = target_put_sess_cmd(cmd);
2710         if (aborted) {
2711                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2712                 wait_for_completion(&compl);
2713                 ret = 1;
2714         }
2715         return ret;
2716 }
2717 EXPORT_SYMBOL(transport_generic_free_cmd);
2718
2719 /**
2720  * target_get_sess_cmd - Add command to active ->sess_cmd_list
2721  * @se_cmd:     command descriptor to add
2722  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2723  */
2724 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2725 {
2726         struct se_session *se_sess = se_cmd->se_sess;
2727         unsigned long flags;
2728         int ret = 0;
2729
2730         /*
2731          * Add a second kref if the fabric caller is expecting to handle
2732          * fabric acknowledgement that requires two target_put_sess_cmd()
2733          * invocations before se_cmd descriptor release.
2734          */
2735         if (ack_kref) {
2736                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2737                         return -EINVAL;
2738
2739                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2740         }
2741
2742         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2743         if (se_sess->sess_tearing_down) {
2744                 ret = -ESHUTDOWN;
2745                 goto out;
2746         }
2747         se_cmd->transport_state |= CMD_T_PRE_EXECUTE;
2748         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2749         percpu_ref_get(&se_sess->cmd_count);
2750 out:
2751         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2752
2753         if (ret && ack_kref)
2754                 target_put_sess_cmd(se_cmd);
2755
2756         return ret;
2757 }
2758 EXPORT_SYMBOL(target_get_sess_cmd);
2759
2760 static void target_free_cmd_mem(struct se_cmd *cmd)
2761 {
2762         transport_free_pages(cmd);
2763
2764         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2765                 core_tmr_release_req(cmd->se_tmr_req);
2766         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2767                 kfree(cmd->t_task_cdb);
2768 }
2769
2770 static void target_release_cmd_kref(struct kref *kref)
2771 {
2772         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2773         struct se_session *se_sess = se_cmd->se_sess;
2774         struct completion *compl = se_cmd->compl;
2775         unsigned long flags;
2776
2777         if (se_sess) {
2778                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2779                 list_del_init(&se_cmd->se_cmd_list);
2780                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2781         }
2782
2783         target_free_cmd_mem(se_cmd);
2784         se_cmd->se_tfo->release_cmd(se_cmd);
2785         if (compl)
2786                 complete(compl);
2787
2788         percpu_ref_put(&se_sess->cmd_count);
2789 }
2790
2791 /**
2792  * target_put_sess_cmd - decrease the command reference count
2793  * @se_cmd:     command to drop a reference from
2794  *
2795  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2796  * refcount to drop to zero. Returns zero otherwise.
2797  */
2798 int target_put_sess_cmd(struct se_cmd *se_cmd)
2799 {
2800         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2801 }
2802 EXPORT_SYMBOL(target_put_sess_cmd);
2803
2804 static const char *data_dir_name(enum dma_data_direction d)
2805 {
2806         switch (d) {
2807         case DMA_BIDIRECTIONAL: return "BIDI";
2808         case DMA_TO_DEVICE:     return "WRITE";
2809         case DMA_FROM_DEVICE:   return "READ";
2810         case DMA_NONE:          return "NONE";
2811         }
2812
2813         return "(?)";
2814 }
2815
2816 static const char *cmd_state_name(enum transport_state_table t)
2817 {
2818         switch (t) {
2819         case TRANSPORT_NO_STATE:        return "NO_STATE";
2820         case TRANSPORT_NEW_CMD:         return "NEW_CMD";
2821         case TRANSPORT_WRITE_PENDING:   return "WRITE_PENDING";
2822         case TRANSPORT_PROCESSING:      return "PROCESSING";
2823         case TRANSPORT_COMPLETE:        return "COMPLETE";
2824         case TRANSPORT_ISTATE_PROCESSING:
2825                                         return "ISTATE_PROCESSING";
2826         case TRANSPORT_COMPLETE_QF_WP:  return "COMPLETE_QF_WP";
2827         case TRANSPORT_COMPLETE_QF_OK:  return "COMPLETE_QF_OK";
2828         case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
2829         }
2830
2831         return "(?)";
2832 }
2833
2834 static void target_append_str(char **str, const char *txt)
2835 {
2836         char *prev = *str;
2837
2838         *str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
2839                 kstrdup(txt, GFP_ATOMIC);
2840         kfree(prev);
2841 }
2842
2843 /*
2844  * Convert a transport state bitmask into a string. The caller is
2845  * responsible for freeing the returned pointer.
2846  */
2847 static char *target_ts_to_str(u32 ts)
2848 {
2849         char *str = NULL;
2850
2851         if (ts & CMD_T_ABORTED)
2852                 target_append_str(&str, "aborted");
2853         if (ts & CMD_T_ACTIVE)
2854                 target_append_str(&str, "active");
2855         if (ts & CMD_T_COMPLETE)
2856                 target_append_str(&str, "complete");
2857         if (ts & CMD_T_SENT)
2858                 target_append_str(&str, "sent");
2859         if (ts & CMD_T_STOP)
2860                 target_append_str(&str, "stop");
2861         if (ts & CMD_T_FABRIC_STOP)
2862                 target_append_str(&str, "fabric_stop");
2863
2864         return str;
2865 }
2866
2867 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
2868 {
2869         switch (tmf) {
2870         case TMR_ABORT_TASK:            return "ABORT_TASK";
2871         case TMR_ABORT_TASK_SET:        return "ABORT_TASK_SET";
2872         case TMR_CLEAR_ACA:             return "CLEAR_ACA";
2873         case TMR_CLEAR_TASK_SET:        return "CLEAR_TASK_SET";
2874         case TMR_LUN_RESET:             return "LUN_RESET";
2875         case TMR_TARGET_WARM_RESET:     return "TARGET_WARM_RESET";
2876         case TMR_TARGET_COLD_RESET:     return "TARGET_COLD_RESET";
2877         case TMR_UNKNOWN:               break;
2878         }
2879         return "(?)";
2880 }
2881
2882 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
2883 {
2884         char *ts_str = target_ts_to_str(cmd->transport_state);
2885         const u8 *cdb = cmd->t_task_cdb;
2886         struct se_tmr_req *tmf = cmd->se_tmr_req;
2887
2888         if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2889                 pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
2890                          pfx, cdb[0], cdb[1], cmd->tag,
2891                          data_dir_name(cmd->data_direction),
2892                          cmd->se_tfo->get_cmd_state(cmd),
2893                          cmd_state_name(cmd->t_state), cmd->data_length,
2894                          kref_read(&cmd->cmd_kref), ts_str);
2895         } else {
2896                 pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
2897                          pfx, target_tmf_name(tmf->function), cmd->tag,
2898                          tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
2899                          cmd_state_name(cmd->t_state),
2900                          kref_read(&cmd->cmd_kref), ts_str);
2901         }
2902         kfree(ts_str);
2903 }
2904 EXPORT_SYMBOL(target_show_cmd);
2905
2906 /**
2907  * target_sess_cmd_list_set_waiting - Set sess_tearing_down so no new commands are queued.
2908  * @se_sess:    session to flag
2909  */
2910 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2911 {
2912         unsigned long flags;
2913
2914         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2915         se_sess->sess_tearing_down = 1;
2916         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2917
2918         percpu_ref_kill(&se_sess->cmd_count);
2919 }
2920 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2921
2922 /**
2923  * target_wait_for_sess_cmds - Wait for outstanding commands
2924  * @se_sess:    session to wait for active I/O
2925  */
2926 void target_wait_for_sess_cmds(struct se_session *se_sess)
2927 {
2928         struct se_cmd *cmd;
2929         int ret;
2930
2931         WARN_ON_ONCE(!se_sess->sess_tearing_down);
2932
2933         do {
2934                 ret = wait_event_timeout(se_sess->cmd_list_wq,
2935                                 percpu_ref_is_zero(&se_sess->cmd_count),
2936                                 180 * HZ);
2937                 list_for_each_entry(cmd, &se_sess->sess_cmd_list, se_cmd_list)
2938                         target_show_cmd("session shutdown: still waiting for ",
2939                                         cmd);
2940         } while (ret <= 0);
2941 }
2942 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2943
2944 static void target_lun_confirm(struct percpu_ref *ref)
2945 {
2946         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2947
2948         complete(&lun->lun_ref_comp);
2949 }
2950
2951 void transport_clear_lun_ref(struct se_lun *lun)
2952 {
2953         /*
2954          * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2955          * the initial reference and schedule confirm kill to be
2956          * executed after one full RCU grace period has completed.
2957          */
2958         percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2959         /*
2960          * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2961          * to call target_lun_confirm after lun->lun_ref has been marked
2962          * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2963          * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2964          * fails for all new incoming I/O.
2965          */
2966         wait_for_completion(&lun->lun_ref_comp);
2967         /*
2968          * The second completion waits for percpu_ref_put_many() to
2969          * invoke ->release() after lun->lun_ref has switched to
2970          * atomic_t mode, and lun->lun_ref.count has reached zero.
2971          *
2972          * At this point all target-core lun->lun_ref references have
2973          * been dropped via transport_lun_remove_cmd(), and it's safe
2974          * to proceed with the remaining LUN shutdown.
2975          */
2976         wait_for_completion(&lun->lun_shutdown_comp);
2977 }
2978
2979 static bool
2980 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2981                            bool *aborted, bool *tas, unsigned long *flags)
2982         __releases(&cmd->t_state_lock)
2983         __acquires(&cmd->t_state_lock)
2984 {
2985         lockdep_assert_held(&cmd->t_state_lock);
2986
2987         if (fabric_stop)
2988                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2989
2990         if (cmd->transport_state & CMD_T_ABORTED)
2991                 *aborted = true;
2992
2993         if (cmd->transport_state & CMD_T_TAS)
2994                 *tas = true;
2995
2996         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2997             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2998                 return false;
2999
3000         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
3001             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3002                 return false;
3003
3004         if (!(cmd->transport_state & CMD_T_ACTIVE))
3005                 return false;
3006
3007         if (fabric_stop && *aborted)
3008                 return false;
3009
3010         cmd->transport_state |= CMD_T_STOP;
3011
3012         target_show_cmd("wait_for_tasks: Stopping ", cmd);
3013
3014         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
3015
3016         while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
3017                                             180 * HZ))
3018                 target_show_cmd("wait for tasks: ", cmd);
3019
3020         spin_lock_irqsave(&cmd->t_state_lock, *flags);
3021         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
3022
3023         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
3024                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
3025
3026         return true;
3027 }
3028
3029 /**
3030  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3031  * @cmd: command to wait on
3032  */
3033 bool transport_wait_for_tasks(struct se_cmd *cmd)
3034 {
3035         unsigned long flags;
3036         bool ret, aborted = false, tas = false;
3037
3038         spin_lock_irqsave(&cmd->t_state_lock, flags);
3039         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3040         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3041
3042         return ret;
3043 }
3044 EXPORT_SYMBOL(transport_wait_for_tasks);
3045
3046 struct sense_info {
3047         u8 key;
3048         u8 asc;
3049         u8 ascq;
3050         bool add_sector_info;
3051 };
3052
3053 static const struct sense_info sense_info_table[] = {
3054         [TCM_NO_SENSE] = {
3055                 .key = NOT_READY
3056         },
3057         [TCM_NON_EXISTENT_LUN] = {
3058                 .key = ILLEGAL_REQUEST,
3059                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3060         },
3061         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
3062                 .key = ILLEGAL_REQUEST,
3063                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3064         },
3065         [TCM_SECTOR_COUNT_TOO_MANY] = {
3066                 .key = ILLEGAL_REQUEST,
3067                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3068         },
3069         [TCM_UNKNOWN_MODE_PAGE] = {
3070                 .key = ILLEGAL_REQUEST,
3071                 .asc = 0x24, /* INVALID FIELD IN CDB */
3072         },
3073         [TCM_CHECK_CONDITION_ABORT_CMD] = {
3074                 .key = ABORTED_COMMAND,
3075                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3076                 .ascq = 0x03,
3077         },
3078         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
3079                 .key = ABORTED_COMMAND,
3080                 .asc = 0x0c, /* WRITE ERROR */
3081                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3082         },
3083         [TCM_INVALID_CDB_FIELD] = {
3084                 .key = ILLEGAL_REQUEST,
3085                 .asc = 0x24, /* INVALID FIELD IN CDB */
3086         },
3087         [TCM_INVALID_PARAMETER_LIST] = {
3088                 .key = ILLEGAL_REQUEST,
3089                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3090         },
3091         [TCM_TOO_MANY_TARGET_DESCS] = {
3092                 .key = ILLEGAL_REQUEST,
3093                 .asc = 0x26,
3094                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3095         },
3096         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3097                 .key = ILLEGAL_REQUEST,
3098                 .asc = 0x26,
3099                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3100         },
3101         [TCM_TOO_MANY_SEGMENT_DESCS] = {
3102                 .key = ILLEGAL_REQUEST,
3103                 .asc = 0x26,
3104                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3105         },
3106         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3107                 .key = ILLEGAL_REQUEST,
3108                 .asc = 0x26,
3109                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3110         },
3111         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3112                 .key = ILLEGAL_REQUEST,
3113                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3114         },
3115         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3116                 .key = ILLEGAL_REQUEST,
3117                 .asc = 0x0c, /* WRITE ERROR */
3118                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3119         },
3120         [TCM_SERVICE_CRC_ERROR] = {
3121                 .key = ABORTED_COMMAND,
3122                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3123                 .ascq = 0x05, /* N/A */
3124         },
3125         [TCM_SNACK_REJECTED] = {
3126                 .key = ABORTED_COMMAND,
3127                 .asc = 0x11, /* READ ERROR */
3128                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3129         },
3130         [TCM_WRITE_PROTECTED] = {
3131                 .key = DATA_PROTECT,
3132                 .asc = 0x27, /* WRITE PROTECTED */
3133         },
3134         [TCM_ADDRESS_OUT_OF_RANGE] = {
3135                 .key = ILLEGAL_REQUEST,
3136                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3137         },
3138         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3139                 .key = UNIT_ATTENTION,
3140         },
3141         [TCM_CHECK_CONDITION_NOT_READY] = {
3142                 .key = NOT_READY,
3143         },
3144         [TCM_MISCOMPARE_VERIFY] = {
3145                 .key = MISCOMPARE,
3146                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3147                 .ascq = 0x00,
3148         },
3149         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3150                 .key = ABORTED_COMMAND,
3151                 .asc = 0x10,
3152                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3153                 .add_sector_info = true,
3154         },
3155         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3156                 .key = ABORTED_COMMAND,
3157                 .asc = 0x10,
3158                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3159                 .add_sector_info = true,
3160         },
3161         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3162                 .key = ABORTED_COMMAND,
3163                 .asc = 0x10,
3164                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3165                 .add_sector_info = true,
3166         },
3167         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3168                 .key = COPY_ABORTED,
3169                 .asc = 0x0d,
3170                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3171
3172         },
3173         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3174                 /*
3175                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
3176                  * Solaris initiators.  Returning NOT READY instead means the
3177                  * operations will be retried a finite number of times and we
3178                  * can survive intermittent errors.
3179                  */
3180                 .key = NOT_READY,
3181                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3182         },
3183         [TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3184                 /*
3185                  * From spc4r22 section5.7.7,5.7.8
3186                  * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3187                  * or a REGISTER AND IGNORE EXISTING KEY service action or
3188                  * REGISTER AND MOVE service actionis attempted,
3189                  * but there are insufficient device server resources to complete the
3190                  * operation, then the command shall be terminated with CHECK CONDITION
3191                  * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3192                  * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3193                  */
3194                 .key = ILLEGAL_REQUEST,
3195                 .asc = 0x55,
3196                 .ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3197         },
3198 };
3199
3200 /**
3201  * translate_sense_reason - translate a sense reason into T10 key, asc and ascq
3202  * @cmd: SCSI command in which the resulting sense buffer or SCSI status will
3203  *   be stored.
3204  * @reason: LIO sense reason code. If this argument has the value
3205  *   TCM_CHECK_CONDITION_UNIT_ATTENTION, try to dequeue a unit attention. If
3206  *   dequeuing a unit attention fails due to multiple commands being processed
3207  *   concurrently, set the command status to BUSY.
3208  *
3209  * Return: 0 upon success or -EINVAL if the sense buffer is too small.
3210  */
3211 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3212 {
3213         const struct sense_info *si;
3214         u8 *buffer = cmd->sense_buffer;
3215         int r = (__force int)reason;
3216         u8 key, asc, ascq;
3217         bool desc_format = target_sense_desc_format(cmd->se_dev);
3218
3219         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
3220                 si = &sense_info_table[r];
3221         else
3222                 si = &sense_info_table[(__force int)
3223                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3224
3225         key = si->key;
3226         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3227                 if (!core_scsi3_ua_for_check_condition(cmd, &key, &asc,
3228                                                        &ascq)) {
3229                         cmd->scsi_status = SAM_STAT_BUSY;
3230                         return;
3231                 }
3232         } else if (si->asc == 0) {
3233                 WARN_ON_ONCE(cmd->scsi_asc == 0);
3234                 asc = cmd->scsi_asc;
3235                 ascq = cmd->scsi_ascq;
3236         } else {
3237                 asc = si->asc;
3238                 ascq = si->ascq;
3239         }
3240
3241         cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3242         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3243         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3244         scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
3245         if (si->add_sector_info)
3246                 WARN_ON_ONCE(scsi_set_sense_information(buffer,
3247                                                         cmd->scsi_sense_length,
3248                                                         cmd->bad_sector) < 0);
3249 }
3250
3251 int
3252 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3253                 sense_reason_t reason, int from_transport)
3254 {
3255         unsigned long flags;
3256
3257         spin_lock_irqsave(&cmd->t_state_lock, flags);
3258         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3259                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3260                 return 0;
3261         }
3262         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3263         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3264
3265         if (!from_transport)
3266                 translate_sense_reason(cmd, reason);
3267
3268         trace_target_cmd_complete(cmd);
3269         return cmd->se_tfo->queue_status(cmd);
3270 }
3271 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3272
3273 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3274         __releases(&cmd->t_state_lock)
3275         __acquires(&cmd->t_state_lock)
3276 {
3277         int ret;
3278
3279         assert_spin_locked(&cmd->t_state_lock);
3280         WARN_ON_ONCE(!irqs_disabled());
3281
3282         if (!(cmd->transport_state & CMD_T_ABORTED))
3283                 return 0;
3284         /*
3285          * If cmd has been aborted but either no status is to be sent or it has
3286          * already been sent, just return
3287          */
3288         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3289                 if (send_status)
3290                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3291                 return 1;
3292         }
3293
3294         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3295                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3296
3297         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3298         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3299         trace_target_cmd_complete(cmd);
3300
3301         spin_unlock_irq(&cmd->t_state_lock);
3302         ret = cmd->se_tfo->queue_status(cmd);
3303         if (ret)
3304                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3305         spin_lock_irq(&cmd->t_state_lock);
3306
3307         return 1;
3308 }
3309
3310 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3311 {
3312         int ret;
3313
3314         spin_lock_irq(&cmd->t_state_lock);
3315         ret = __transport_check_aborted_status(cmd, send_status);
3316         spin_unlock_irq(&cmd->t_state_lock);
3317
3318         return ret;
3319 }
3320 EXPORT_SYMBOL(transport_check_aborted_status);
3321
3322 void transport_send_task_abort(struct se_cmd *cmd)
3323 {
3324         unsigned long flags;
3325         int ret;
3326
3327         spin_lock_irqsave(&cmd->t_state_lock, flags);
3328         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3329                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3330                 return;
3331         }
3332         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3333
3334         /*
3335          * If there are still expected incoming fabric WRITEs, we wait
3336          * until until they have completed before sending a TASK_ABORTED
3337          * response.  This response with TASK_ABORTED status will be
3338          * queued back to fabric module by transport_check_aborted_status().
3339          */
3340         if (cmd->data_direction == DMA_TO_DEVICE) {
3341                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3342                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3343                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3344                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3345                                 goto send_abort;
3346                         }
3347                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3348                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3349                         return;
3350                 }
3351         }
3352 send_abort:
3353         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3354
3355         transport_lun_remove_cmd(cmd);
3356
3357         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3358                  cmd->t_task_cdb[0], cmd->tag);
3359
3360         trace_target_cmd_complete(cmd);
3361         ret = cmd->se_tfo->queue_status(cmd);
3362         if (ret)
3363                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3364 }
3365
3366 static void target_tmr_work(struct work_struct *work)
3367 {
3368         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3369         struct se_device *dev = cmd->se_dev;
3370         struct se_tmr_req *tmr = cmd->se_tmr_req;
3371         unsigned long flags;
3372         int ret;
3373
3374         spin_lock_irqsave(&cmd->t_state_lock, flags);
3375         if (cmd->transport_state & CMD_T_ABORTED) {
3376                 tmr->response = TMR_FUNCTION_REJECTED;
3377                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3378                 goto check_stop;
3379         }
3380         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3381
3382         switch (tmr->function) {
3383         case TMR_ABORT_TASK:
3384                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3385                 break;
3386         case TMR_ABORT_TASK_SET:
3387         case TMR_CLEAR_ACA:
3388         case TMR_CLEAR_TASK_SET:
3389                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3390                 break;
3391         case TMR_LUN_RESET:
3392                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3393                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3394                                          TMR_FUNCTION_REJECTED;
3395                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3396                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3397                                                cmd->orig_fe_lun, 0x29,
3398                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3399                 }
3400                 break;
3401         case TMR_TARGET_WARM_RESET:
3402                 tmr->response = TMR_FUNCTION_REJECTED;
3403                 break;
3404         case TMR_TARGET_COLD_RESET:
3405                 tmr->response = TMR_FUNCTION_REJECTED;
3406                 break;
3407         default:
3408                 pr_err("Unknown TMR function: 0x%02x.\n",
3409                                 tmr->function);
3410                 tmr->response = TMR_FUNCTION_REJECTED;
3411                 break;
3412         }
3413
3414         spin_lock_irqsave(&cmd->t_state_lock, flags);
3415         if (cmd->transport_state & CMD_T_ABORTED) {
3416                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3417                 goto check_stop;
3418         }
3419         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3420
3421         cmd->se_tfo->queue_tm_rsp(cmd);
3422
3423 check_stop:
3424         transport_lun_remove_cmd(cmd);
3425         transport_cmd_check_stop_to_fabric(cmd);
3426 }
3427
3428 int transport_generic_handle_tmr(
3429         struct se_cmd *cmd)
3430 {
3431         unsigned long flags;
3432         bool aborted = false;
3433
3434         spin_lock_irqsave(&cmd->t_state_lock, flags);
3435         if (cmd->transport_state & CMD_T_ABORTED) {
3436                 aborted = true;
3437         } else {
3438                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3439                 cmd->transport_state |= CMD_T_ACTIVE;
3440         }
3441         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3442
3443         if (aborted) {
3444                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3445                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3446                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3447                 transport_lun_remove_cmd(cmd);
3448                 transport_cmd_check_stop_to_fabric(cmd);
3449                 return 0;
3450         }
3451
3452         INIT_WORK(&cmd->work, target_tmr_work);
3453         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3454         return 0;
3455 }
3456 EXPORT_SYMBOL(transport_generic_handle_tmr);
3457
3458 bool
3459 target_check_wce(struct se_device *dev)
3460 {
3461         bool wce = false;
3462
3463         if (dev->transport->get_write_cache)
3464                 wce = dev->transport->get_write_cache(dev);
3465         else if (dev->dev_attrib.emulate_write_cache > 0)
3466                 wce = true;
3467
3468         return wce;
3469 }
3470
3471 bool
3472 target_check_fua(struct se_device *dev)
3473 {
3474         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3475 }