drivers/target/target_core_transport.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * Filename:  target_core_transport.c
   4  *
   5  * This file contains the Generic Target Engine Core.
   6  *
   7  * (c) Copyright 2002-2013 Datera, Inc.
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  ******************************************************************************/
  12
  13 #include <linux/net.h>
  14 #include <linux/delay.h>
  15 #include <linux/string.h>
  16 #include <linux/timer.h>
  17 #include <linux/slab.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/kthread.h>
  20 #include <linux/in.h>
  21 #include <linux/cdrom.h>
  22 #include <linux/module.h>
  23 #include <linux/ratelimit.h>
  24 #include <linux/vmalloc.h>
  25 #include <asm/unaligned.h>
  26 #include <net/sock.h>
  27 #include <net/tcp.h>
  28 #include <scsi/scsi_proto.h>
  29 #include <scsi/scsi_common.h>
  30
  31 #include <target/target_core_base.h>
  32 #include <target/target_core_backend.h>
  33 #include <target/target_core_fabric.h>
  34
  35 #include "target_core_internal.h"
  36 #include "target_core_alua.h"
  37 #include "target_core_pr.h"
  38 #include "target_core_ua.h"
  39
  40 #define CREATE_TRACE_POINTS
  41 #include <trace/events/target.h>
  42
  43 static struct workqueue_struct *target_completion_wq;
  44 static struct kmem_cache *se_sess_cache;
  45 struct kmem_cache *se_ua_cache;
  46 struct kmem_cache *t10_pr_reg_cache;
  47 struct kmem_cache *t10_alua_lu_gp_cache;
  48 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  49 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  50 struct kmem_cache *t10_alua_lba_map_cache;
  51 struct kmem_cache *t10_alua_lba_map_mem_cache;
  52
  53 static void transport_complete_task_attr(struct se_cmd *cmd);
  54 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
  55 static void transport_handle_queue_full(struct se_cmd *cmd,
  56                 struct se_device *dev, int err, bool write_pending);
  57 static void target_complete_ok_work(struct work_struct *work);
  58
  59 int init_se_kmem_caches(void)
  60 {
  61         se_sess_cache = kmem_cache_create("se_sess_cache",
  62                         sizeof(struct se_session), __alignof__(struct se_session),
  63                         0, NULL);
  64         if (!se_sess_cache) {
  65                 pr_err("kmem_cache_create() for struct se_session"
  66                                 " failed\n");
  67                 goto out;
  68         }
  69         se_ua_cache = kmem_cache_create("se_ua_cache",
  70                         sizeof(struct se_ua), __alignof__(struct se_ua),
  71                         0, NULL);
  72         if (!se_ua_cache) {
  73                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  74                 goto out_free_sess_cache;
  75         }
  76         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  77                         sizeof(struct t10_pr_registration),
  78                         __alignof__(struct t10_pr_registration), 0, NULL);
  79         if (!t10_pr_reg_cache) {
  80                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  81                                 " failed\n");
  82                 goto out_free_ua_cache;
  83         }
  84         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  85                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  86                         0, NULL);
  87         if (!t10_alua_lu_gp_cache) {
  88                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
  89                                 " failed\n");
  90                 goto out_free_pr_reg_cache;
  91         }
  92         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
  93                         sizeof(struct t10_alua_lu_gp_member),
  94                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
  95         if (!t10_alua_lu_gp_mem_cache) {
  96                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
  97                                 "cache failed\n");
  98                 goto out_free_lu_gp_cache;
  99         }
 100         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 101                         sizeof(struct t10_alua_tg_pt_gp),
 102                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 103         if (!t10_alua_tg_pt_gp_cache) {
 104                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 105                                 "cache failed\n");
 106                 goto out_free_lu_gp_mem_cache;
 107         }
 108         t10_alua_lba_map_cache = kmem_cache_create(
 109                         "t10_alua_lba_map_cache",
 110                         sizeof(struct t10_alua_lba_map),
 111                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 112         if (!t10_alua_lba_map_cache) {
 113                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 114                                 "cache failed\n");
 115                 goto out_free_tg_pt_gp_cache;
 116         }
 117         t10_alua_lba_map_mem_cache = kmem_cache_create(
 118                         "t10_alua_lba_map_mem_cache",
 119                         sizeof(struct t10_alua_lba_map_member),
 120                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 121         if (!t10_alua_lba_map_mem_cache) {
 122                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 123                                 "cache failed\n");
 124                 goto out_free_lba_map_cache;
 125         }
 126
 127         target_completion_wq = alloc_workqueue("target_completion",
 128                                                WQ_MEM_RECLAIM, 0);
 129         if (!target_completion_wq)
 130                 goto out_free_lba_map_mem_cache;
 131
 132         return 0;
 133
 134 out_free_lba_map_mem_cache:
 135         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 136 out_free_lba_map_cache:
 137         kmem_cache_destroy(t10_alua_lba_map_cache);
 138 out_free_tg_pt_gp_cache:
 139         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 140 out_free_lu_gp_mem_cache:
 141         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 142 out_free_lu_gp_cache:
 143         kmem_cache_destroy(t10_alua_lu_gp_cache);
 144 out_free_pr_reg_cache:
 145         kmem_cache_destroy(t10_pr_reg_cache);
 146 out_free_ua_cache:
 147         kmem_cache_destroy(se_ua_cache);
 148 out_free_sess_cache:
 149         kmem_cache_destroy(se_sess_cache);
 150 out:
 151         return -ENOMEM;
 152 }
 153
 154 void release_se_kmem_caches(void)
 155 {
 156         destroy_workqueue(target_completion_wq);
 157         kmem_cache_destroy(se_sess_cache);
 158         kmem_cache_destroy(se_ua_cache);
 159         kmem_cache_destroy(t10_pr_reg_cache);
 160         kmem_cache_destroy(t10_alua_lu_gp_cache);
 161         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 162         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 163         kmem_cache_destroy(t10_alua_lba_map_cache);
 164         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 165 }
 166
 167 /* This code ensures unique mib indexes are handed out. */
 168 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 169 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 170
 171 /*
 172  * Allocate a new row index for the entry type specified
 173  */
 174 u32 scsi_get_new_index(scsi_index_t type)
 175 {
 176         u32 new_index;
 177
 178         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 179
 180         spin_lock(&scsi_mib_index_lock);
 181         new_index = ++scsi_mib_index[type];
 182         spin_unlock(&scsi_mib_index_lock);
 183
 184         return new_index;
 185 }
 186
 187 void transport_subsystem_check_init(void)
 188 {
 189         int ret;
 190         static int sub_api_initialized;
 191
 192         if (sub_api_initialized)
 193                 return;
 194
 195         ret = IS_ENABLED(CONFIG_TCM_IBLOCK) && request_module("target_core_iblock");
 196         if (ret != 0)
 197                 pr_err("Unable to load target_core_iblock\n");
 198
 199         ret = IS_ENABLED(CONFIG_TCM_FILEIO) && request_module("target_core_file");
 200         if (ret != 0)
 201                 pr_err("Unable to load target_core_file\n");
 202
 203         ret = IS_ENABLED(CONFIG_TCM_PSCSI) && request_module("target_core_pscsi");
 204         if (ret != 0)
 205                 pr_err("Unable to load target_core_pscsi\n");
 206
 207         ret = IS_ENABLED(CONFIG_TCM_USER2) && request_module("target_core_user");
 208         if (ret != 0)
 209                 pr_err("Unable to load target_core_user\n");
 210
 211         sub_api_initialized = 1;
 212 }
 213
 214 static void target_release_sess_cmd_refcnt(struct percpu_ref *ref)
 215 {
 216         struct se_session *sess = container_of(ref, typeof(*sess), cmd_count);
 217
 218         wake_up(&sess->cmd_count_wq);
 219 }
 220
 221 /**
 222  * transport_init_session - initialize a session object
 223  * @se_sess: Session object pointer.
 224  *
 225  * The caller must have zero-initialized @se_sess before calling this function.
 226  */
 227 int transport_init_session(struct se_session *se_sess)
 228 {
 229         INIT_LIST_HEAD(&se_sess->sess_list);
 230         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 231         spin_lock_init(&se_sess->sess_cmd_lock);
 232         init_waitqueue_head(&se_sess->cmd_count_wq);
 233         init_completion(&se_sess->stop_done);
 234         atomic_set(&se_sess->stopped, 0);
 235         return percpu_ref_init(&se_sess->cmd_count,
 236                                target_release_sess_cmd_refcnt, 0, GFP_KERNEL);
 237 }
 238 EXPORT_SYMBOL(transport_init_session);
 239
 240 void transport_uninit_session(struct se_session *se_sess)
 241 {
 242         /*
 243          * Drivers like iscsi and loop do not call target_stop_session
 244          * during session shutdown so we have to drop the ref taken at init
 245          * time here.
 246          */
 247         if (!atomic_read(&se_sess->stopped))
 248                 percpu_ref_put(&se_sess->cmd_count);
 249
 250         percpu_ref_exit(&se_sess->cmd_count);
 251 }
 252
 253 /**
 254  * transport_alloc_session - allocate a session object and initialize it
 255  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
 256  */
 257 struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
 258 {
 259         struct se_session *se_sess;
 260         int ret;
 261
 262         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 263         if (!se_sess) {
 264                 pr_err("Unable to allocate struct se_session from"
 265                                 " se_sess_cache\n");
 266                 return ERR_PTR(-ENOMEM);
 267         }
 268         ret = transport_init_session(se_sess);
 269         if (ret < 0) {
 270                 kmem_cache_free(se_sess_cache, se_sess);
 271                 return ERR_PTR(ret);
 272         }
 273         se_sess->sup_prot_ops = sup_prot_ops;
 274
 275         return se_sess;
 276 }
 277 EXPORT_SYMBOL(transport_alloc_session);
 278
 279 /**
 280  * transport_alloc_session_tags - allocate target driver private data
 281  * @se_sess:  Session pointer.
 282  * @tag_num:  Maximum number of in-flight commands between initiator and target.
 283  * @tag_size: Size in bytes of the private data a target driver associates with
 284  *            each command.
 285  */
 286 int transport_alloc_session_tags(struct se_session *se_sess,
 287                                  unsigned int tag_num, unsigned int tag_size)
 288 {
 289         int rc;
 290
 291         se_sess->sess_cmd_map = kvcalloc(tag_size, tag_num,
 292                                          GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 293         if (!se_sess->sess_cmd_map) {
 294                 pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 295                 return -ENOMEM;
 296         }
 297
 298         rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
 299                         false, GFP_KERNEL, NUMA_NO_NODE);
 300         if (rc < 0) {
 301                 pr_err("Unable to init se_sess->sess_tag_pool,"
 302                         " tag_num: %u\n", tag_num);
 303                 kvfree(se_sess->sess_cmd_map);
 304                 se_sess->sess_cmd_map = NULL;
 305                 return -ENOMEM;
 306         }
 307
 308         return 0;
 309 }
 310 EXPORT_SYMBOL(transport_alloc_session_tags);
 311
 312 /**
 313  * transport_init_session_tags - allocate a session and target driver private data
 314  * @tag_num:  Maximum number of in-flight commands between initiator and target.
 315  * @tag_size: Size in bytes of the private data a target driver associates with
 316  *            each command.
 317  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
 318  */
 319 static struct se_session *
 320 transport_init_session_tags(unsigned int tag_num, unsigned int tag_size,
 321                             enum target_prot_op sup_prot_ops)
 322 {
 323         struct se_session *se_sess;
 324         int rc;
 325
 326         if (tag_num != 0 && !tag_size) {
 327                 pr_err("init_session_tags called with percpu-ida tag_num:"
 328                        " %u, but zero tag_size\n", tag_num);
 329                 return ERR_PTR(-EINVAL);
 330         }
 331         if (!tag_num && tag_size) {
 332                 pr_err("init_session_tags called with percpu-ida tag_size:"
 333                        " %u, but zero tag_num\n", tag_size);
 334                 return ERR_PTR(-EINVAL);
 335         }
 336
 337         se_sess = transport_alloc_session(sup_prot_ops);
 338         if (IS_ERR(se_sess))
 339                 return se_sess;
 340
 341         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 342         if (rc < 0) {
 343                 transport_free_session(se_sess);
 344                 return ERR_PTR(-ENOMEM);
 345         }
 346
 347         return se_sess;
 348 }
 349
 350 /*
 351  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 352  */
 353 void __transport_register_session(
 354         struct se_portal_group *se_tpg,
 355         struct se_node_acl *se_nacl,
 356         struct se_session *se_sess,
 357         void *fabric_sess_ptr)
 358 {
 359         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 360         unsigned char buf[PR_REG_ISID_LEN];
 361         unsigned long flags;
 362
 363         se_sess->se_tpg = se_tpg;
 364         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 365         /*
 366          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 367          *
 368          * Only set for struct se_session's that will actually be moving I/O.
 369          * eg: *NOT* discovery sessions.
 370          */
 371         if (se_nacl) {
 372                 /*
 373                  *
 374                  * Determine if fabric allows for T10-PI feature bits exposed to
 375                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 376                  *
 377                  * If so, then always save prot_type on a per se_node_acl node
 378                  * basis and re-instate the previous sess_prot_type to avoid
 379                  * disabling PI from below any previously initiator side
 380                  * registered LUNs.
 381                  */
 382                 if (se_nacl->saved_prot_type)
 383                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 384                 else if (tfo->tpg_check_prot_fabric_only)
 385                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 386                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 387                 /*
 388                  * If the fabric module supports an ISID based TransportID,
 389                  * save this value in binary from the fabric I_T Nexus now.
 390                  */
 391                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 392                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 393                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 394                                         &buf[0], PR_REG_ISID_LEN);
 395                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 396                 }
 397
 398                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 399                 /*
 400                  * The se_nacl->nacl_sess pointer will be set to the
 401                  * last active I_T Nexus for each struct se_node_acl.
 402                  */
 403                 se_nacl->nacl_sess = se_sess;
 404
 405                 list_add_tail(&se_sess->sess_acl_list,
 406                               &se_nacl->acl_sess_list);
 407                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 408         }
 409         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 410
 411         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 412                 se_tpg->se_tpg_tfo->fabric_name, se_sess->fabric_sess_ptr);
 413 }
 414 EXPORT_SYMBOL(__transport_register_session);
 415
 416 void transport_register_session(
 417         struct se_portal_group *se_tpg,
 418         struct se_node_acl *se_nacl,
 419         struct se_session *se_sess,
 420         void *fabric_sess_ptr)
 421 {
 422         unsigned long flags;
 423
 424         spin_lock_irqsave(&se_tpg->session_lock, flags);
 425         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 426         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 427 }
 428 EXPORT_SYMBOL(transport_register_session);
 429
 430 struct se_session *
 431 target_setup_session(struct se_portal_group *tpg,
 432                      unsigned int tag_num, unsigned int tag_size,
 433                      enum target_prot_op prot_op,
 434                      const char *initiatorname, void *private,
 435                      int (*callback)(struct se_portal_group *,
 436                                      struct se_session *, void *))
 437 {
 438         struct se_session *sess;
 439
 440         /*
 441          * If the fabric driver is using percpu-ida based pre allocation
 442          * of I/O descriptor tags, go ahead and perform that setup now..
 443          */
 444         if (tag_num != 0)
 445                 sess = transport_init_session_tags(tag_num, tag_size, prot_op);
 446         else
 447                 sess = transport_alloc_session(prot_op);
 448
 449         if (IS_ERR(sess))
 450                 return sess;
 451
 452         sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
 453                                         (unsigned char *)initiatorname);
 454         if (!sess->se_node_acl) {
 455                 transport_free_session(sess);
 456                 return ERR_PTR(-EACCES);
 457         }
 458         /*
 459          * Go ahead and perform any remaining fabric setup that is
 460          * required before transport_register_session().
 461          */
 462         if (callback != NULL) {
 463                 int rc = callback(tpg, sess, private);
 464                 if (rc) {
 465                         transport_free_session(sess);
 466                         return ERR_PTR(rc);
 467                 }
 468         }
 469
 470         transport_register_session(tpg, sess->se_node_acl, sess, private);
 471         return sess;
 472 }
 473 EXPORT_SYMBOL(target_setup_session);
 474
 475 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 476 {
 477         struct se_session *se_sess;
 478         ssize_t len = 0;
 479
 480         spin_lock_bh(&se_tpg->session_lock);
 481         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 482                 if (!se_sess->se_node_acl)
 483                         continue;
 484                 if (!se_sess->se_node_acl->dynamic_node_acl)
 485                         continue;
 486                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 487                         break;
 488
 489                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 490                                 se_sess->se_node_acl->initiatorname);
 491                 len += 1; /* Include NULL terminator */
 492         }
 493         spin_unlock_bh(&se_tpg->session_lock);
 494
 495         return len;
 496 }
 497 EXPORT_SYMBOL(target_show_dynamic_sessions);
 498
 499 static void target_complete_nacl(struct kref *kref)
 500 {
 501         struct se_node_acl *nacl = container_of(kref,
 502                                 struct se_node_acl, acl_kref);
 503         struct se_portal_group *se_tpg = nacl->se_tpg;
 504
 505         if (!nacl->dynamic_stop) {
 506                 complete(&nacl->acl_free_comp);
 507                 return;
 508         }
 509
 510         mutex_lock(&se_tpg->acl_node_mutex);
 511         list_del_init(&nacl->acl_list);
 512         mutex_unlock(&se_tpg->acl_node_mutex);
 513
 514         core_tpg_wait_for_nacl_pr_ref(nacl);
 515         core_free_device_list_for_node(nacl, se_tpg);
 516         kfree(nacl);
 517 }
 518
 519 void target_put_nacl(struct se_node_acl *nacl)
 520 {
 521         kref_put(&nacl->acl_kref, target_complete_nacl);
 522 }
 523 EXPORT_SYMBOL(target_put_nacl);
 524
 525 void transport_deregister_session_configfs(struct se_session *se_sess)
 526 {
 527         struct se_node_acl *se_nacl;
 528         unsigned long flags;
 529         /*
 530          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 531          */
 532         se_nacl = se_sess->se_node_acl;
 533         if (se_nacl) {
 534                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 535                 if (!list_empty(&se_sess->sess_acl_list))
 536                         list_del_init(&se_sess->sess_acl_list);
 537                 /*
 538                  * If the session list is empty, then clear the pointer.
 539                  * Otherwise, set the struct se_session pointer from the tail
 540                  * element of the per struct se_node_acl active session list.
 541                  */
 542                 if (list_empty(&se_nacl->acl_sess_list))
 543                         se_nacl->nacl_sess = NULL;
 544                 else {
 545                         se_nacl->nacl_sess = container_of(
 546                                         se_nacl->acl_sess_list.prev,
 547                                         struct se_session, sess_acl_list);
 548                 }
 549                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 550         }
 551 }
 552 EXPORT_SYMBOL(transport_deregister_session_configfs);
 553
 554 void transport_free_session(struct se_session *se_sess)
 555 {
 556         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 557
 558         /*
 559          * Drop the se_node_acl->nacl_kref obtained from within
 560          * core_tpg_get_initiator_node_acl().
 561          */
 562         if (se_nacl) {
 563                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 564                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 565                 unsigned long flags;
 566
 567                 se_sess->se_node_acl = NULL;
 568
 569                 /*
 570                  * Also determine if we need to drop the extra ->cmd_kref if
 571                  * it had been previously dynamically generated, and
 572                  * the endpoint is not caching dynamic ACLs.
 573                  */
 574                 mutex_lock(&se_tpg->acl_node_mutex);
 575                 if (se_nacl->dynamic_node_acl &&
 576                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 577                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 578                         if (list_empty(&se_nacl->acl_sess_list))
 579                                 se_nacl->dynamic_stop = true;
 580                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 581
 582                         if (se_nacl->dynamic_stop)
 583                                 list_del_init(&se_nacl->acl_list);
 584                 }
 585                 mutex_unlock(&se_tpg->acl_node_mutex);
 586
 587                 if (se_nacl->dynamic_stop)
 588                         target_put_nacl(se_nacl);
 589
 590                 target_put_nacl(se_nacl);
 591         }
 592         if (se_sess->sess_cmd_map) {
 593                 sbitmap_queue_free(&se_sess->sess_tag_pool);
 594                 kvfree(se_sess->sess_cmd_map);
 595         }
 596         transport_uninit_session(se_sess);
 597         kmem_cache_free(se_sess_cache, se_sess);
 598 }
 599 EXPORT_SYMBOL(transport_free_session);
 600
 601 static int target_release_res(struct se_device *dev, void *data)
 602 {
 603         struct se_session *sess = data;
 604
 605         if (dev->reservation_holder == sess)
 606                 target_release_reservation(dev);
 607         return 0;
 608 }
 609
 610 void transport_deregister_session(struct se_session *se_sess)
 611 {
 612         struct se_portal_group *se_tpg = se_sess->se_tpg;
 613         unsigned long flags;
 614
 615         if (!se_tpg) {
 616                 transport_free_session(se_sess);
 617                 return;
 618         }
 619
 620         spin_lock_irqsave(&se_tpg->session_lock, flags);
 621         list_del(&se_sess->sess_list);
 622         se_sess->se_tpg = NULL;
 623         se_sess->fabric_sess_ptr = NULL;
 624         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 625
 626         /*
 627          * Since the session is being removed, release SPC-2
 628          * reservations held by the session that is disappearing.
 629          */
 630         target_for_each_device(target_release_res, se_sess);
 631
 632         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 633                 se_tpg->se_tpg_tfo->fabric_name);
 634         /*
 635          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 636          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 637          * removal context from within transport_free_session() code.
 638          *
 639          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 640          * to release all remaining generate_node_acl=1 created ACL resources.
 641          */
 642
 643         transport_free_session(se_sess);
 644 }
 645 EXPORT_SYMBOL(transport_deregister_session);
 646
 647 void target_remove_session(struct se_session *se_sess)
 648 {
 649         transport_deregister_session_configfs(se_sess);
 650         transport_deregister_session(se_sess);
 651 }
 652 EXPORT_SYMBOL(target_remove_session);
 653
 654 static void target_remove_from_state_list(struct se_cmd *cmd)
 655 {
 656         struct se_device *dev = cmd->se_dev;
 657         unsigned long flags;
 658
 659         if (!dev)
 660                 return;
 661
 662         spin_lock_irqsave(&dev->queues[cmd->cpuid].lock, flags);
 663         if (cmd->state_active) {
 664                 list_del(&cmd->state_list);
 665                 cmd->state_active = false;
 666         }
 667         spin_unlock_irqrestore(&dev->queues[cmd->cpuid].lock, flags);
 668 }
 669
 670 /*
 671  * This function is called by the target core after the target core has
 672  * finished processing a SCSI command or SCSI TMF. Both the regular command
 673  * processing code and the code for aborting commands can call this
 674  * function. CMD_T_STOP is set if and only if another thread is waiting
 675  * inside transport_wait_for_tasks() for t_transport_stop_comp.
 676  */
 677 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 678 {
 679         unsigned long flags;
 680
 681         target_remove_from_state_list(cmd);
 682
 683         /*
 684          * Clear struct se_cmd->se_lun before the handoff to FE.
 685          */
 686         cmd->se_lun = NULL;
 687
 688         spin_lock_irqsave(&cmd->t_state_lock, flags);
 689         /*
 690          * Determine if frontend context caller is requesting the stopping of
 691          * this command for frontend exceptions.
 692          */
 693         if (cmd->transport_state & CMD_T_STOP) {
 694                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 695                         __func__, __LINE__, cmd->tag);
 696
 697                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 698
 699                 complete_all(&cmd->t_transport_stop_comp);
 700                 return 1;
 701         }
 702         cmd->transport_state &= ~CMD_T_ACTIVE;
 703         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 704
 705         /*
 706          * Some fabric modules like tcm_loop can release their internally
 707          * allocated I/O reference and struct se_cmd now.
 708          *
 709          * Fabric modules are expected to return '1' here if the se_cmd being
 710          * passed is released at this point, or zero if not being released.
 711          */
 712         return cmd->se_tfo->check_stop_free(cmd);
 713 }
 714
 715 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 716 {
 717         struct se_lun *lun = cmd->se_lun;
 718
 719         if (!lun)
 720                 return;
 721
 722         if (cmpxchg(&cmd->lun_ref_active, true, false))
 723                 percpu_ref_put(&lun->lun_ref);
 724 }
 725
 726 static void target_complete_failure_work(struct work_struct *work)
 727 {
 728         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 729
 730         transport_generic_request_failure(cmd,
 731                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 732 }
 733
 734 /*
 735  * Used when asking transport to copy Sense Data from the underlying
 736  * Linux/SCSI struct scsi_cmnd
 737  */
 738 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 739 {
 740         struct se_device *dev = cmd->se_dev;
 741
 742         WARN_ON(!cmd->se_lun);
 743
 744         if (!dev)
 745                 return NULL;
 746
 747         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 748                 return NULL;
 749
 750         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 751
 752         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 753                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 754         return cmd->sense_buffer;
 755 }
 756
 757 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
 758 {
 759         unsigned char *cmd_sense_buf;
 760         unsigned long flags;
 761
 762         spin_lock_irqsave(&cmd->t_state_lock, flags);
 763         cmd_sense_buf = transport_get_sense_buffer(cmd);
 764         if (!cmd_sense_buf) {
 765                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 766                 return;
 767         }
 768
 769         cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
 770         memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
 771         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 772 }
 773 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
 774
 775 static void target_handle_abort(struct se_cmd *cmd)
 776 {
 777         bool tas = cmd->transport_state & CMD_T_TAS;
 778         bool ack_kref = cmd->se_cmd_flags & SCF_ACK_KREF;
 779         int ret;
 780
 781         pr_debug("tag %#llx: send_abort_response = %d\n", cmd->tag, tas);
 782
 783         if (tas) {
 784                 if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
 785                         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
 786                         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
 787                                  cmd->t_task_cdb[0], cmd->tag);
 788                         trace_target_cmd_complete(cmd);
 789                         ret = cmd->se_tfo->queue_status(cmd);
 790                         if (ret) {
 791                                 transport_handle_queue_full(cmd, cmd->se_dev,
 792                                                             ret, false);
 793                                 return;
 794                         }
 795                 } else {
 796                         cmd->se_tmr_req->response = TMR_FUNCTION_REJECTED;
 797                         cmd->se_tfo->queue_tm_rsp(cmd);
 798                 }
 799         } else {
 800                 /*
 801                  * Allow the fabric driver to unmap any resources before
 802                  * releasing the descriptor via TFO->release_cmd().
 803                  */
 804                 cmd->se_tfo->aborted_task(cmd);
 805                 if (ack_kref)
 806                         WARN_ON_ONCE(target_put_sess_cmd(cmd) != 0);
 807                 /*
 808                  * To do: establish a unit attention condition on the I_T
 809                  * nexus associated with cmd. See also the paragraph "Aborting
 810                  * commands" in SAM.
 811                  */
 812         }
 813
 814         WARN_ON_ONCE(kref_read(&cmd->cmd_kref) == 0);
 815
 816         transport_lun_remove_cmd(cmd);
 817
 818         transport_cmd_check_stop_to_fabric(cmd);
 819 }
 820
 821 static void target_abort_work(struct work_struct *work)
 822 {
 823         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 824
 825         target_handle_abort(cmd);
 826 }
 827
 828 static bool target_cmd_interrupted(struct se_cmd *cmd)
 829 {
 830         int post_ret;
 831
 832         if (cmd->transport_state & CMD_T_ABORTED) {
 833                 if (cmd->transport_complete_callback)
 834                         cmd->transport_complete_callback(cmd, false, &post_ret);
 835                 INIT_WORK(&cmd->work, target_abort_work);
 836                 queue_work(target_completion_wq, &cmd->work);
 837                 return true;
 838         } else if (cmd->transport_state & CMD_T_STOP) {
 839                 if (cmd->transport_complete_callback)
 840                         cmd->transport_complete_callback(cmd, false, &post_ret);
 841                 complete_all(&cmd->t_transport_stop_comp);
 842                 return true;
 843         }
 844
 845         return false;
 846 }
 847
 848 /* May be called from interrupt context so must not sleep. */
 849 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 850 {
 851         int success;
 852         unsigned long flags;
 853
 854         if (target_cmd_interrupted(cmd))
 855                 return;
 856
 857         cmd->scsi_status = scsi_status;
 858
 859         spin_lock_irqsave(&cmd->t_state_lock, flags);
 860         switch (cmd->scsi_status) {
 861         case SAM_STAT_CHECK_CONDITION:
 862                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 863                         success = 1;
 864                 else
 865                         success = 0;
 866                 break;
 867         default:
 868                 success = 1;
 869                 break;
 870         }
 871
 872         cmd->t_state = TRANSPORT_COMPLETE;
 873         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 874         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 875
 876         INIT_WORK(&cmd->work, success ? target_complete_ok_work :
 877                   target_complete_failure_work);
 878         queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 879 }
 880 EXPORT_SYMBOL(target_complete_cmd);
 881
 882 void target_set_cmd_data_length(struct se_cmd *cmd, int length)
 883 {
 884         if (length < cmd->data_length) {
 885                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 886                         cmd->residual_count += cmd->data_length - length;
 887                 } else {
 888                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 889                         cmd->residual_count = cmd->data_length - length;
 890                 }
 891
 892                 cmd->data_length = length;
 893         }
 894 }
 895 EXPORT_SYMBOL(target_set_cmd_data_length);
 896
 897 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 898 {
 899         if (scsi_status == SAM_STAT_GOOD ||
 900             cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) {
 901                 target_set_cmd_data_length(cmd, length);
 902         }
 903
 904         target_complete_cmd(cmd, scsi_status);
 905 }
 906 EXPORT_SYMBOL(target_complete_cmd_with_length);
 907
 908 static void target_add_to_state_list(struct se_cmd *cmd)
 909 {
 910         struct se_device *dev = cmd->se_dev;
 911         unsigned long flags;
 912
 913         spin_lock_irqsave(&dev->queues[cmd->cpuid].lock, flags);
 914         if (!cmd->state_active) {
 915                 list_add_tail(&cmd->state_list,
 916                               &dev->queues[cmd->cpuid].state_list);
 917                 cmd->state_active = true;
 918         }
 919         spin_unlock_irqrestore(&dev->queues[cmd->cpuid].lock, flags);
 920 }
 921
 922 /*
 923  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 924  */
 925 static void transport_write_pending_qf(struct se_cmd *cmd);
 926 static void transport_complete_qf(struct se_cmd *cmd);
 927
 928 void target_qf_do_work(struct work_struct *work)
 929 {
 930         struct se_device *dev = container_of(work, struct se_device,
 931                                         qf_work_queue);
 932         LIST_HEAD(qf_cmd_list);
 933         struct se_cmd *cmd, *cmd_tmp;
 934
 935         spin_lock_irq(&dev->qf_cmd_lock);
 936         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 937         spin_unlock_irq(&dev->qf_cmd_lock);
 938
 939         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 940                 list_del(&cmd->se_qf_node);
 941                 atomic_dec_mb(&dev->dev_qf_count);
 942
 943                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 944                         " context: %s\n", cmd->se_tfo->fabric_name, cmd,
 945                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 946                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 947                         : "UNKNOWN");
 948
 949                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 950                         transport_write_pending_qf(cmd);
 951                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 952                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 953                         transport_complete_qf(cmd);
 954         }
 955 }
 956
 957 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 958 {
 959         switch (cmd->data_direction) {
 960         case DMA_NONE:
 961                 return "NONE";
 962         case DMA_FROM_DEVICE:
 963                 return "READ";
 964         case DMA_TO_DEVICE:
 965                 return "WRITE";
 966         case DMA_BIDIRECTIONAL:
 967                 return "BIDI";
 968         default:
 969                 break;
 970         }
 971
 972         return "UNKNOWN";
 973 }
 974
 975 void transport_dump_dev_state(
 976         struct se_device *dev,
 977         char *b,
 978         int *bl)
 979 {
 980         *bl += sprintf(b + *bl, "Status: ");
 981         if (dev->export_count)
 982                 *bl += sprintf(b + *bl, "ACTIVATED");
 983         else
 984                 *bl += sprintf(b + *bl, "DEACTIVATED");
 985
 986         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 987         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 988                 dev->dev_attrib.block_size,
 989                 dev->dev_attrib.hw_max_sectors);
 990         *bl += sprintf(b + *bl, "        ");
 991 }
 992
 993 void transport_dump_vpd_proto_id(
 994         struct t10_vpd *vpd,
 995         unsigned char *p_buf,
 996         int p_buf_len)
 997 {
 998         unsigned char buf[VPD_TMP_BUF_SIZE];
 999         int len;
1000
1001         memset(buf, 0, VPD_TMP_BUF_SIZE);
1002         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
1003
1004         switch (vpd->protocol_identifier) {
1005         case 0x00:
1006                 sprintf(buf+len, "Fibre Channel\n");
1007                 break;
1008         case 0x10:
1009                 sprintf(buf+len, "Parallel SCSI\n");
1010                 break;
1011         case 0x20:
1012                 sprintf(buf+len, "SSA\n");
1013                 break;
1014         case 0x30:
1015                 sprintf(buf+len, "IEEE 1394\n");
1016                 break;
1017         case 0x40:
1018                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
1019                                 " Protocol\n");
1020                 break;
1021         case 0x50:
1022                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
1023                 break;
1024         case 0x60:
1025                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
1026                 break;
1027         case 0x70:
1028                 sprintf(buf+len, "Automation/Drive Interface Transport"
1029                                 " Protocol\n");
1030                 break;
1031         case 0x80:
1032                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
1033                 break;
1034         default:
1035                 sprintf(buf+len, "Unknown 0x%02x\n",
1036                                 vpd->protocol_identifier);
1037                 break;
1038         }
1039
1040         if (p_buf)
1041                 strncpy(p_buf, buf, p_buf_len);
1042         else
1043                 pr_debug("%s", buf);
1044 }
1045
1046 void
1047 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
1048 {
1049         /*
1050          * Check if the Protocol Identifier Valid (PIV) bit is set..
1051          *
1052          * from spc3r23.pdf section 7.5.1
1053          */
1054          if (page_83[1] & 0x80) {
1055                 vpd->protocol_identifier = (page_83[0] & 0xf0);
1056                 vpd->protocol_identifier_set = 1;
1057                 transport_dump_vpd_proto_id(vpd, NULL, 0);
1058         }
1059 }
1060 EXPORT_SYMBOL(transport_set_vpd_proto_id);
1061
1062 int transport_dump_vpd_assoc(
1063         struct t10_vpd *vpd,
1064         unsigned char *p_buf,
1065         int p_buf_len)
1066 {
1067         unsigned char buf[VPD_TMP_BUF_SIZE];
1068         int ret = 0;
1069         int len;
1070
1071         memset(buf, 0, VPD_TMP_BUF_SIZE);
1072         len = sprintf(buf, "T10 VPD Identifier Association: ");
1073
1074         switch (vpd->association) {
1075         case 0x00:
1076                 sprintf(buf+len, "addressed logical unit\n");
1077                 break;
1078         case 0x10:
1079                 sprintf(buf+len, "target port\n");
1080                 break;
1081         case 0x20:
1082                 sprintf(buf+len, "SCSI target device\n");
1083                 break;
1084         default:
1085                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
1086                 ret = -EINVAL;
1087                 break;
1088         }
1089
1090         if (p_buf)
1091                 strncpy(p_buf, buf, p_buf_len);
1092         else
1093                 pr_debug("%s", buf);
1094
1095         return ret;
1096 }
1097
1098 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
1099 {
1100         /*
1101          * The VPD identification association..
1102          *
1103          * from spc3r23.pdf Section 7.6.3.1 Table 297
1104          */
1105         vpd->association = (page_83[1] & 0x30);
1106         return transport_dump_vpd_assoc(vpd, NULL, 0);
1107 }
1108 EXPORT_SYMBOL(transport_set_vpd_assoc);
1109
1110 int transport_dump_vpd_ident_type(
1111         struct t10_vpd *vpd,
1112         unsigned char *p_buf,
1113         int p_buf_len)
1114 {
1115         unsigned char buf[VPD_TMP_BUF_SIZE];
1116         int ret = 0;
1117         int len;
1118
1119         memset(buf, 0, VPD_TMP_BUF_SIZE);
1120         len = sprintf(buf, "T10 VPD Identifier Type: ");
1121
1122         switch (vpd->device_identifier_type) {
1123         case 0x00:
1124                 sprintf(buf+len, "Vendor specific\n");
1125                 break;
1126         case 0x01:
1127                 sprintf(buf+len, "T10 Vendor ID based\n");
1128                 break;
1129         case 0x02:
1130                 sprintf(buf+len, "EUI-64 based\n");
1131                 break;
1132         case 0x03:
1133                 sprintf(buf+len, "NAA\n");
1134                 break;
1135         case 0x04:
1136                 sprintf(buf+len, "Relative target port identifier\n");
1137                 break;
1138         case 0x08:
1139                 sprintf(buf+len, "SCSI name string\n");
1140                 break;
1141         default:
1142                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1143                                 vpd->device_identifier_type);
1144                 ret = -EINVAL;
1145                 break;
1146         }
1147
1148         if (p_buf) {
1149                 if (p_buf_len < strlen(buf)+1)
1150                         return -EINVAL;
1151                 strncpy(p_buf, buf, p_buf_len);
1152         } else {
1153                 pr_debug("%s", buf);
1154         }
1155
1156         return ret;
1157 }
1158
1159 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1160 {
1161         /*
1162          * The VPD identifier type..
1163          *
1164          * from spc3r23.pdf Section 7.6.3.1 Table 298
1165          */
1166         vpd->device_identifier_type = (page_83[1] & 0x0f);
1167         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1168 }
1169 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1170
1171 int transport_dump_vpd_ident(
1172         struct t10_vpd *vpd,
1173         unsigned char *p_buf,
1174         int p_buf_len)
1175 {
1176         unsigned char buf[VPD_TMP_BUF_SIZE];
1177         int ret = 0;
1178
1179         memset(buf, 0, VPD_TMP_BUF_SIZE);
1180
1181         switch (vpd->device_identifier_code_set) {
1182         case 0x01: /* Binary */
1183                 snprintf(buf, sizeof(buf),
1184                         "T10 VPD Binary Device Identifier: %s\n",
1185                         &vpd->device_identifier[0]);
1186                 break;
1187         case 0x02: /* ASCII */
1188                 snprintf(buf, sizeof(buf),
1189                         "T10 VPD ASCII Device Identifier: %s\n",
1190                         &vpd->device_identifier[0]);
1191                 break;
1192         case 0x03: /* UTF-8 */
1193                 snprintf(buf, sizeof(buf),
1194                         "T10 VPD UTF-8 Device Identifier: %s\n",
1195                         &vpd->device_identifier[0]);
1196                 break;
1197         default:
1198                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1199                         " 0x%02x", vpd->device_identifier_code_set);
1200                 ret = -EINVAL;
1201                 break;
1202         }
1203
1204         if (p_buf)
1205                 strncpy(p_buf, buf, p_buf_len);
1206         else
1207                 pr_debug("%s", buf);
1208
1209         return ret;
1210 }
1211
1212 int
1213 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1214 {
1215         static const char hex_str[] = "0123456789abcdef";
1216         int j = 0, i = 4; /* offset to start of the identifier */
1217
1218         /*
1219          * The VPD Code Set (encoding)
1220          *
1221          * from spc3r23.pdf Section 7.6.3.1 Table 296
1222          */
1223         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1224         switch (vpd->device_identifier_code_set) {
1225         case 0x01: /* Binary */
1226                 vpd->device_identifier[j++] =
1227                                 hex_str[vpd->device_identifier_type];
1228                 while (i < (4 + page_83[3])) {
1229                         vpd->device_identifier[j++] =
1230                                 hex_str[(page_83[i] & 0xf0) >> 4];
1231                         vpd->device_identifier[j++] =
1232                                 hex_str[page_83[i] & 0x0f];
1233                         i++;
1234                 }
1235                 break;
1236         case 0x02: /* ASCII */
1237         case 0x03: /* UTF-8 */
1238                 while (i < (4 + page_83[3]))
1239                         vpd->device_identifier[j++] = page_83[i++];
1240                 break;
1241         default:
1242                 break;
1243         }
1244
1245         return transport_dump_vpd_ident(vpd, NULL, 0);
1246 }
1247 EXPORT_SYMBOL(transport_set_vpd_ident);
1248
1249 static sense_reason_t
1250 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1251                                unsigned int size)
1252 {
1253         u32 mtl;
1254
1255         if (!cmd->se_tfo->max_data_sg_nents)
1256                 return TCM_NO_SENSE;
1257         /*
1258          * Check if fabric enforced maximum SGL entries per I/O descriptor
1259          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1260          * residual_count and reduce original cmd->data_length to maximum
1261          * length based on single PAGE_SIZE entry scatter-lists.
1262          */
1263         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1264         if (cmd->data_length > mtl) {
1265                 /*
1266                  * If an existing CDB overflow is present, calculate new residual
1267                  * based on CDB size minus fabric maximum transfer length.
1268                  *
1269                  * If an existing CDB underflow is present, calculate new residual
1270                  * based on original cmd->data_length minus fabric maximum transfer
1271                  * length.
1272                  *
1273                  * Otherwise, set the underflow residual based on cmd->data_length
1274                  * minus fabric maximum transfer length.
1275                  */
1276                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1277                         cmd->residual_count = (size - mtl);
1278                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1279                         u32 orig_dl = size + cmd->residual_count;
1280                         cmd->residual_count = (orig_dl - mtl);
1281                 } else {
1282                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1283                         cmd->residual_count = (cmd->data_length - mtl);
1284                 }
1285                 cmd->data_length = mtl;
1286                 /*
1287                  * Reset sbc_check_prot() calculated protection payload
1288                  * length based upon the new smaller MTL.
1289                  */
1290                 if (cmd->prot_length) {
1291                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1292                         cmd->prot_length = dev->prot_length * sectors;
1293                 }
1294         }
1295         return TCM_NO_SENSE;
1296 }
1297
1298 /**
1299  * target_cmd_size_check - Check whether there will be a residual.
1300  * @cmd: SCSI command.
1301  * @size: Data buffer size derived from CDB. The data buffer size provided by
1302  *   the SCSI transport driver is available in @cmd->data_length.
1303  *
1304  * Compare the data buffer size from the CDB with the data buffer limit from the transport
1305  * header. Set @cmd->residual_count and SCF_OVERFLOW_BIT or SCF_UNDERFLOW_BIT if necessary.
1306  *
1307  * Note: target drivers set @cmd->data_length by calling __target_init_cmd().
1308  *
1309  * Return: TCM_NO_SENSE
1310  */
1311 sense_reason_t
1312 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1313 {
1314         struct se_device *dev = cmd->se_dev;
1315
1316         if (cmd->unknown_data_length) {
1317                 cmd->data_length = size;
1318         } else if (size != cmd->data_length) {
1319                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1320                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1321                         " 0x%02x\n", cmd->se_tfo->fabric_name,
1322                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1323                 /*
1324                  * For READ command for the overflow case keep the existing
1325                  * fabric provided ->data_length. Otherwise for the underflow
1326                  * case, reset ->data_length to the smaller SCSI expected data
1327                  * transfer length.
1328                  */
1329                 if (size > cmd->data_length) {
1330                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1331                         cmd->residual_count = (size - cmd->data_length);
1332                 } else {
1333                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1334                         cmd->residual_count = (cmd->data_length - size);
1335                         /*
1336                          * Do not truncate ->data_length for WRITE command to
1337                          * dump all payload
1338                          */
1339                         if (cmd->data_direction == DMA_FROM_DEVICE) {
1340                                 cmd->data_length = size;
1341                         }
1342                 }
1343
1344                 if (cmd->data_direction == DMA_TO_DEVICE) {
1345                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1346                                 pr_err_ratelimited("Rejecting underflow/overflow"
1347                                                    " for WRITE data CDB\n");
1348                                 return TCM_INVALID_FIELD_IN_COMMAND_IU;
1349                         }
1350                         /*
1351                          * Some fabric drivers like iscsi-target still expect to
1352                          * always reject overflow writes.  Reject this case until
1353                          * full fabric driver level support for overflow writes
1354                          * is introduced tree-wide.
1355                          */
1356                         if (size > cmd->data_length) {
1357                                 pr_err_ratelimited("Rejecting overflow for"
1358                                                    " WRITE control CDB\n");
1359                                 return TCM_INVALID_CDB_FIELD;
1360                         }
1361                 }
1362         }
1363
1364         return target_check_max_data_sg_nents(cmd, dev, size);
1365
1366 }
1367
1368 /*
1369  * Used by fabric modules containing a local struct se_cmd within their
1370  * fabric dependent per I/O descriptor.
1371  *
1372  * Preserves the value of @cmd->tag.
1373  */
1374 void __target_init_cmd(
1375         struct se_cmd *cmd,
1376         const struct target_core_fabric_ops *tfo,
1377         struct se_session *se_sess,
1378         u32 data_length,
1379         int data_direction,
1380         int task_attr,
1381         unsigned char *sense_buffer, u64 unpacked_lun)
1382 {
1383         INIT_LIST_HEAD(&cmd->se_delayed_node);
1384         INIT_LIST_HEAD(&cmd->se_qf_node);
1385         INIT_LIST_HEAD(&cmd->se_cmd_list);
1386         INIT_LIST_HEAD(&cmd->state_list);
1387         init_completion(&cmd->t_transport_stop_comp);
1388         cmd->free_compl = NULL;
1389         cmd->abrt_compl = NULL;
1390         spin_lock_init(&cmd->t_state_lock);
1391         INIT_WORK(&cmd->work, NULL);
1392         kref_init(&cmd->cmd_kref);
1393
1394         cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1395         cmd->se_tfo = tfo;
1396         cmd->se_sess = se_sess;
1397         cmd->data_length = data_length;
1398         cmd->data_direction = data_direction;
1399         cmd->sam_task_attr = task_attr;
1400         cmd->sense_buffer = sense_buffer;
1401         cmd->orig_fe_lun = unpacked_lun;
1402
1403         if (!(cmd->se_cmd_flags & SCF_USE_CPUID))
1404                 cmd->cpuid = smp_processor_id();
1405
1406         cmd->state_active = false;
1407 }
1408 EXPORT_SYMBOL(__target_init_cmd);
1409
1410 static sense_reason_t
1411 transport_check_alloc_task_attr(struct se_cmd *cmd)
1412 {
1413         struct se_device *dev = cmd->se_dev;
1414
1415         /*
1416          * Check if SAM Task Attribute emulation is enabled for this
1417          * struct se_device storage object
1418          */
1419         if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1420                 return 0;
1421
1422         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1423                 pr_debug("SAM Task Attribute ACA"
1424                         " emulation is not supported\n");
1425                 return TCM_INVALID_CDB_FIELD;
1426         }
1427
1428         return 0;
1429 }
1430
1431 sense_reason_t
1432 target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb)
1433 {
1434         sense_reason_t ret;
1435
1436         /*
1437          * Ensure that the received CDB is less than the max (252 + 8) bytes
1438          * for VARIABLE_LENGTH_CMD
1439          */
1440         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1441                 pr_err("Received SCSI CDB with command_size: %d that"
1442                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1443                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1444                 ret = TCM_INVALID_CDB_FIELD;
1445                 goto err;
1446         }
1447         /*
1448          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1449          * allocate the additional extended CDB buffer now..  Otherwise
1450          * setup the pointer from __t_task_cdb to t_task_cdb.
1451          */
1452         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1453                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1454                                                 GFP_KERNEL);
1455                 if (!cmd->t_task_cdb) {
1456                         pr_err("Unable to allocate cmd->t_task_cdb"
1457                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1458                                 scsi_command_size(cdb),
1459                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1460                         ret = TCM_OUT_OF_RESOURCES;
1461                         goto err;
1462                 }
1463         }
1464         /*
1465          * Copy the original CDB into cmd->
1466          */
1467         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1468
1469         trace_target_sequencer_start(cmd);
1470         return 0;
1471
1472 err:
1473         /*
1474          * Copy the CDB here to allow trace_target_cmd_complete() to
1475          * print the cdb to the trace buffers.
1476          */
1477         memcpy(cmd->t_task_cdb, cdb, min(scsi_command_size(cdb),
1478                                          (unsigned int)TCM_MAX_COMMAND_SIZE));
1479         return ret;
1480 }
1481 EXPORT_SYMBOL(target_cmd_init_cdb);
1482
1483 sense_reason_t
1484 target_cmd_parse_cdb(struct se_cmd *cmd)
1485 {
1486         struct se_device *dev = cmd->se_dev;
1487         sense_reason_t ret;
1488
1489         ret = dev->transport->parse_cdb(cmd);
1490         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1491                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1492                                     cmd->se_tfo->fabric_name,
1493                                     cmd->se_sess->se_node_acl->initiatorname,
1494                                     cmd->t_task_cdb[0]);
1495         if (ret)
1496                 return ret;
1497
1498         ret = transport_check_alloc_task_attr(cmd);
1499         if (ret)
1500                 return ret;
1501
1502         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1503         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1504         return 0;
1505 }
1506 EXPORT_SYMBOL(target_cmd_parse_cdb);
1507
1508 /*
1509  * Used by fabric module frontends to queue tasks directly.
1510  * May only be used from process context.
1511  */
1512 int transport_handle_cdb_direct(
1513         struct se_cmd *cmd)
1514 {
1515         sense_reason_t ret;
1516
1517         might_sleep();
1518
1519         if (!cmd->se_lun) {
1520                 dump_stack();
1521                 pr_err("cmd->se_lun is NULL\n");
1522                 return -EINVAL;
1523         }
1524
1525         /*
1526          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1527          * outstanding descriptors are handled correctly during shutdown via
1528          * transport_wait_for_tasks()
1529          *
1530          * Also, we don't take cmd->t_state_lock here as we only expect
1531          * this to be called for initial descriptor submission.
1532          */
1533         cmd->t_state = TRANSPORT_NEW_CMD;
1534         cmd->transport_state |= CMD_T_ACTIVE;
1535
1536         /*
1537          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1538          * so follow TRANSPORT_NEW_CMD processing thread context usage
1539          * and call transport_generic_request_failure() if necessary..
1540          */
1541         ret = transport_generic_new_cmd(cmd);
1542         if (ret)
1543                 transport_generic_request_failure(cmd, ret);
1544         return 0;
1545 }
1546 EXPORT_SYMBOL(transport_handle_cdb_direct);
1547
1548 sense_reason_t
1549 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1550                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1551 {
1552         if (!sgl || !sgl_count)
1553                 return 0;
1554
1555         /*
1556          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1557          * scatterlists already have been set to follow what the fabric
1558          * passes for the original expected data transfer length.
1559          */
1560         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1561                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1562                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1563                 return TCM_INVALID_CDB_FIELD;
1564         }
1565
1566         cmd->t_data_sg = sgl;
1567         cmd->t_data_nents = sgl_count;
1568         cmd->t_bidi_data_sg = sgl_bidi;
1569         cmd->t_bidi_data_nents = sgl_bidi_count;
1570
1571         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1572         return 0;
1573 }
1574
1575 /**
1576  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1577  *                       se_cmd + use pre-allocated SGL memory.
1578  *
1579  * @se_cmd: command descriptor to submit
1580  * @se_sess: associated se_sess for endpoint
1581  * @cdb: pointer to SCSI CDB
1582  * @sense: pointer to SCSI sense buffer
1583  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1584  * @data_length: fabric expected data transfer length
1585  * @task_attr: SAM task attribute
1586  * @data_dir: DMA data direction
1587  * @flags: flags for command submission from target_sc_flags_tables
1588  * @sgl: struct scatterlist memory for unidirectional mapping
1589  * @sgl_count: scatterlist count for unidirectional mapping
1590  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1591  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1592  * @sgl_prot: struct scatterlist memory protection information
1593  * @sgl_prot_count: scatterlist count for protection information
1594  *
1595  * Task tags are supported if the caller has set @se_cmd->tag.
1596  *
1597  * Returns non zero to signal active I/O shutdown failure.  All other
1598  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1599  * but still return zero here.
1600  *
1601  * This may only be called from process context, and also currently
1602  * assumes internal allocation of fabric payload buffer by target-core.
1603  */
1604 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1605                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1606                 u32 data_length, int task_attr, int data_dir, int flags,
1607                 struct scatterlist *sgl, u32 sgl_count,
1608                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1609                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1610 {
1611         struct se_portal_group *se_tpg;
1612         sense_reason_t rc;
1613         int ret;
1614
1615         might_sleep();
1616
1617         se_tpg = se_sess->se_tpg;
1618         BUG_ON(!se_tpg);
1619         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1620
1621         if (flags & TARGET_SCF_USE_CPUID)
1622                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1623         /*
1624          * Initialize se_cmd for target operation.  From this point
1625          * exceptions are handled by sending exception status via
1626          * target_core_fabric_ops->queue_status() callback
1627          */
1628         __target_init_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1629                           data_length, data_dir, task_attr, sense,
1630                           unpacked_lun);
1631
1632         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1633                 se_cmd->unknown_data_length = 1;
1634         /*
1635          * Obtain struct se_cmd->cmd_kref reference. A second kref_get here is
1636          * necessary for fabrics using TARGET_SCF_ACK_KREF that expect a second
1637          * kref_put() to happen during fabric packet acknowledgement.
1638          */
1639         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1640         if (ret)
1641                 return ret;
1642         /*
1643          * Signal bidirectional data payloads to target-core
1644          */
1645         if (flags & TARGET_SCF_BIDI_OP)
1646                 se_cmd->se_cmd_flags |= SCF_BIDI;
1647
1648         rc = target_cmd_init_cdb(se_cmd, cdb);
1649         if (rc) {
1650                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1651                 target_put_sess_cmd(se_cmd);
1652                 return 0;
1653         }
1654
1655         /*
1656          * Locate se_lun pointer and attach it to struct se_cmd
1657          */
1658         rc = transport_lookup_cmd_lun(se_cmd);
1659         if (rc) {
1660                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1661                 target_put_sess_cmd(se_cmd);
1662                 return 0;
1663         }
1664
1665         rc = target_cmd_parse_cdb(se_cmd);
1666         if (rc != 0) {
1667                 transport_generic_request_failure(se_cmd, rc);
1668                 return 0;
1669         }
1670
1671         /*
1672          * Save pointers for SGLs containing protection information,
1673          * if present.
1674          */
1675         if (sgl_prot_count) {
1676                 se_cmd->t_prot_sg = sgl_prot;
1677                 se_cmd->t_prot_nents = sgl_prot_count;
1678                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1679         }
1680
1681         /*
1682          * When a non zero sgl_count has been passed perform SGL passthrough
1683          * mapping for pre-allocated fabric memory instead of having target
1684          * core perform an internal SGL allocation..
1685          */
1686         if (sgl_count != 0) {
1687                 BUG_ON(!sgl);
1688
1689                 /*
1690                  * A work-around for tcm_loop as some userspace code via
1691                  * scsi-generic do not memset their associated read buffers,
1692                  * so go ahead and do that here for type non-data CDBs.  Also
1693                  * note that this is currently guaranteed to be a single SGL
1694                  * for this case by target core in target_setup_cmd_from_cdb()
1695                  * -> transport_generic_cmd_sequencer().
1696                  */
1697                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1698                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1699                         unsigned char *buf = NULL;
1700
1701                         if (sgl)
1702                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1703
1704                         if (buf) {
1705                                 memset(buf, 0, sgl->length);
1706                                 kunmap(sg_page(sgl));
1707                         }
1708                 }
1709
1710                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1711                                 sgl_bidi, sgl_bidi_count);
1712                 if (rc != 0) {
1713                         transport_generic_request_failure(se_cmd, rc);
1714                         return 0;
1715                 }
1716         }
1717
1718         /*
1719          * Check if we need to delay processing because of ALUA
1720          * Active/NonOptimized primary access state..
1721          */
1722         core_alua_check_nonop_delay(se_cmd);
1723
1724         transport_handle_cdb_direct(se_cmd);
1725         return 0;
1726 }
1727 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1728
1729 /**
1730  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1731  *
1732  * @se_cmd: command descriptor to submit
1733  * @se_sess: associated se_sess for endpoint
1734  * @cdb: pointer to SCSI CDB
1735  * @sense: pointer to SCSI sense buffer
1736  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1737  * @data_length: fabric expected data transfer length
1738  * @task_attr: SAM task attribute
1739  * @data_dir: DMA data direction
1740  * @flags: flags for command submission from target_sc_flags_tables
1741  *
1742  * Task tags are supported if the caller has set @se_cmd->tag.
1743  *
1744  * Returns non zero to signal active I/O shutdown failure.  All other
1745  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1746  * but still return zero here.
1747  *
1748  * This may only be called from process context, and also currently
1749  * assumes internal allocation of fabric payload buffer by target-core.
1750  *
1751  * It also assumes interal target core SGL memory allocation.
1752  */
1753 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1754                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1755                 u32 data_length, int task_attr, int data_dir, int flags)
1756 {
1757         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1758                         unpacked_lun, data_length, task_attr, data_dir,
1759                         flags, NULL, 0, NULL, 0, NULL, 0);
1760 }
1761 EXPORT_SYMBOL(target_submit_cmd);
1762
1763 static void target_complete_tmr_failure(struct work_struct *work)
1764 {
1765         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1766
1767         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1768         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1769
1770         transport_lun_remove_cmd(se_cmd);
1771         transport_cmd_check_stop_to_fabric(se_cmd);
1772 }
1773
1774 /**
1775  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1776  *                     for TMR CDBs
1777  *
1778  * @se_cmd: command descriptor to submit
1779  * @se_sess: associated se_sess for endpoint
1780  * @sense: pointer to SCSI sense buffer
1781  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1782  * @fabric_tmr_ptr: fabric context for TMR req
1783  * @tm_type: Type of TM request
1784  * @gfp: gfp type for caller
1785  * @tag: referenced task tag for TMR_ABORT_TASK
1786  * @flags: submit cmd flags
1787  *
1788  * Callable from all contexts.
1789  **/
1790
1791 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1792                 unsigned char *sense, u64 unpacked_lun,
1793                 void *fabric_tmr_ptr, unsigned char tm_type,
1794                 gfp_t gfp, u64 tag, int flags)
1795 {
1796         struct se_portal_group *se_tpg;
1797         int ret;
1798
1799         se_tpg = se_sess->se_tpg;
1800         BUG_ON(!se_tpg);
1801
1802         __target_init_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1803                           0, DMA_NONE, TCM_SIMPLE_TAG, sense, unpacked_lun);
1804         /*
1805          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1806          * allocation failure.
1807          */
1808         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1809         if (ret < 0)
1810                 return -ENOMEM;
1811
1812         if (tm_type == TMR_ABORT_TASK)
1813                 se_cmd->se_tmr_req->ref_task_tag = tag;
1814
1815         /* See target_submit_cmd for commentary */
1816         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1817         if (ret) {
1818                 core_tmr_release_req(se_cmd->se_tmr_req);
1819                 return ret;
1820         }
1821
1822         ret = transport_lookup_tmr_lun(se_cmd);
1823         if (ret)
1824                 goto failure;
1825
1826         transport_generic_handle_tmr(se_cmd);
1827         return 0;
1828
1829         /*
1830          * For callback during failure handling, push this work off
1831          * to process context with TMR_LUN_DOES_NOT_EXIST status.
1832          */
1833 failure:
1834         INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1835         schedule_work(&se_cmd->work);
1836         return 0;
1837 }
1838 EXPORT_SYMBOL(target_submit_tmr);
1839
1840 /*
1841  * Handle SAM-esque emulation for generic transport request failures.
1842  */
1843 void transport_generic_request_failure(struct se_cmd *cmd,
1844                 sense_reason_t sense_reason)
1845 {
1846         int ret = 0, post_ret;
1847
1848         pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
1849                  sense_reason);
1850         target_show_cmd("-----[ ", cmd);
1851
1852         /*
1853          * For SAM Task Attribute emulation for failed struct se_cmd
1854          */
1855         transport_complete_task_attr(cmd);
1856
1857         if (cmd->transport_complete_callback)
1858                 cmd->transport_complete_callback(cmd, false, &post_ret);
1859
1860         if (cmd->transport_state & CMD_T_ABORTED) {
1861                 INIT_WORK(&cmd->work, target_abort_work);
1862                 queue_work(target_completion_wq, &cmd->work);
1863                 return;
1864         }
1865
1866         switch (sense_reason) {
1867         case TCM_NON_EXISTENT_LUN:
1868         case TCM_UNSUPPORTED_SCSI_OPCODE:
1869         case TCM_INVALID_CDB_FIELD:
1870         case TCM_INVALID_PARAMETER_LIST:
1871         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1872         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1873         case TCM_UNKNOWN_MODE_PAGE:
1874         case TCM_WRITE_PROTECTED:
1875         case TCM_ADDRESS_OUT_OF_RANGE:
1876         case TCM_CHECK_CONDITION_ABORT_CMD:
1877         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1878         case TCM_CHECK_CONDITION_NOT_READY:
1879         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1880         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1881         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1882         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1883         case TCM_TOO_MANY_TARGET_DESCS:
1884         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1885         case TCM_TOO_MANY_SEGMENT_DESCS:
1886         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1887         case TCM_INVALID_FIELD_IN_COMMAND_IU:
1888                 break;
1889         case TCM_OUT_OF_RESOURCES:
1890                 cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
1891                 goto queue_status;
1892         case TCM_LUN_BUSY:
1893                 cmd->scsi_status = SAM_STAT_BUSY;
1894                 goto queue_status;
1895         case TCM_RESERVATION_CONFLICT:
1896                 /*
1897                  * No SENSE Data payload for this case, set SCSI Status
1898                  * and queue the response to $FABRIC_MOD.
1899                  *
1900                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1901                  */
1902                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1903                 /*
1904                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1905                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1906                  * CONFLICT STATUS.
1907                  *
1908                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1909                  */
1910                 if (cmd->se_sess &&
1911                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl
1912                                         == TARGET_UA_INTLCK_CTRL_ESTABLISH_UA) {
1913                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1914                                                cmd->orig_fe_lun, 0x2C,
1915                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1916                 }
1917
1918                 goto queue_status;
1919         default:
1920                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1921                         cmd->t_task_cdb[0], sense_reason);
1922                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1923                 break;
1924         }
1925
1926         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1927         if (ret)
1928                 goto queue_full;
1929
1930 check_stop:
1931         transport_lun_remove_cmd(cmd);
1932         transport_cmd_check_stop_to_fabric(cmd);
1933         return;
1934
1935 queue_status:
1936         trace_target_cmd_complete(cmd);
1937         ret = cmd->se_tfo->queue_status(cmd);
1938         if (!ret)
1939                 goto check_stop;
1940 queue_full:
1941         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1942 }
1943 EXPORT_SYMBOL(transport_generic_request_failure);
1944
1945 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1946 {
1947         sense_reason_t ret;
1948
1949         if (!cmd->execute_cmd) {
1950                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1951                 goto err;
1952         }
1953         if (do_checks) {
1954                 /*
1955                  * Check for an existing UNIT ATTENTION condition after
1956                  * target_handle_task_attr() has done SAM task attr
1957                  * checking, and possibly have already defered execution
1958                  * out to target_restart_delayed_cmds() context.
1959                  */
1960                 ret = target_scsi3_ua_check(cmd);
1961                 if (ret)
1962                         goto err;
1963
1964                 ret = target_alua_state_check(cmd);
1965                 if (ret)
1966                         goto err;
1967
1968                 ret = target_check_reservation(cmd);
1969                 if (ret) {
1970                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1971                         goto err;
1972                 }
1973         }
1974
1975         ret = cmd->execute_cmd(cmd);
1976         if (!ret)
1977                 return;
1978 err:
1979         spin_lock_irq(&cmd->t_state_lock);
1980         cmd->transport_state &= ~CMD_T_SENT;
1981         spin_unlock_irq(&cmd->t_state_lock);
1982
1983         transport_generic_request_failure(cmd, ret);
1984 }
1985
1986 static int target_write_prot_action(struct se_cmd *cmd)
1987 {
1988         u32 sectors;
1989         /*
1990          * Perform WRITE_INSERT of PI using software emulation when backend
1991          * device has PI enabled, if the transport has not already generated
1992          * PI using hardware WRITE_INSERT offload.
1993          */
1994         switch (cmd->prot_op) {
1995         case TARGET_PROT_DOUT_INSERT:
1996                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1997                         sbc_dif_generate(cmd);
1998                 break;
1999         case TARGET_PROT_DOUT_STRIP:
2000                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
2001                         break;
2002
2003                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
2004                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2005                                              sectors, 0, cmd->t_prot_sg, 0);
2006                 if (unlikely(cmd->pi_err)) {
2007                         spin_lock_irq(&cmd->t_state_lock);
2008                         cmd->transport_state &= ~CMD_T_SENT;
2009                         spin_unlock_irq(&cmd->t_state_lock);
2010                         transport_generic_request_failure(cmd, cmd->pi_err);
2011                         return -1;
2012                 }
2013                 break;
2014         default:
2015                 break;
2016         }
2017
2018         return 0;
2019 }
2020
2021 static bool target_handle_task_attr(struct se_cmd *cmd)
2022 {
2023         struct se_device *dev = cmd->se_dev;
2024
2025         if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2026                 return false;
2027
2028         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
2029
2030         /*
2031          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
2032          * to allow the passed struct se_cmd list of tasks to the front of the list.
2033          */
2034         switch (cmd->sam_task_attr) {
2035         case TCM_HEAD_TAG:
2036                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
2037                          cmd->t_task_cdb[0]);
2038                 return false;
2039         case TCM_ORDERED_TAG:
2040                 atomic_inc_mb(&dev->dev_ordered_sync);
2041
2042                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
2043                          cmd->t_task_cdb[0]);
2044
2045                 /*
2046                  * Execute an ORDERED command if no other older commands
2047                  * exist that need to be completed first.
2048                  */
2049                 if (!atomic_read(&dev->simple_cmds))
2050                         return false;
2051                 break;
2052         default:
2053                 /*
2054                  * For SIMPLE and UNTAGGED Task Attribute commands
2055                  */
2056                 atomic_inc_mb(&dev->simple_cmds);
2057                 break;
2058         }
2059
2060         if (atomic_read(&dev->dev_ordered_sync) == 0)
2061                 return false;
2062
2063         spin_lock(&dev->delayed_cmd_lock);
2064         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
2065         spin_unlock(&dev->delayed_cmd_lock);
2066
2067         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
2068                 cmd->t_task_cdb[0], cmd->sam_task_attr);
2069         return true;
2070 }
2071
2072 void target_execute_cmd(struct se_cmd *cmd)
2073 {
2074         /*
2075          * Determine if frontend context caller is requesting the stopping of
2076          * this command for frontend exceptions.
2077          *
2078          * If the received CDB has already been aborted stop processing it here.
2079          */
2080         if (target_cmd_interrupted(cmd))
2081                 return;
2082
2083         spin_lock_irq(&cmd->t_state_lock);
2084         cmd->t_state = TRANSPORT_PROCESSING;
2085         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
2086         spin_unlock_irq(&cmd->t_state_lock);
2087
2088         if (target_write_prot_action(cmd))
2089                 return;
2090
2091         if (target_handle_task_attr(cmd)) {
2092                 spin_lock_irq(&cmd->t_state_lock);
2093                 cmd->transport_state &= ~CMD_T_SENT;
2094                 spin_unlock_irq(&cmd->t_state_lock);
2095                 return;
2096         }
2097
2098         __target_execute_cmd(cmd, true);
2099 }
2100 EXPORT_SYMBOL(target_execute_cmd);
2101
2102 /*
2103  * Process all commands up to the last received ORDERED task attribute which
2104  * requires another blocking boundary
2105  */
2106 static void target_restart_delayed_cmds(struct se_device *dev)
2107 {
2108         for (;;) {
2109                 struct se_cmd *cmd;
2110
2111                 spin_lock(&dev->delayed_cmd_lock);
2112                 if (list_empty(&dev->delayed_cmd_list)) {
2113                         spin_unlock(&dev->delayed_cmd_lock);
2114                         break;
2115                 }
2116
2117                 cmd = list_entry(dev->delayed_cmd_list.next,
2118                                  struct se_cmd, se_delayed_node);
2119                 list_del(&cmd->se_delayed_node);
2120                 spin_unlock(&dev->delayed_cmd_lock);
2121
2122                 cmd->transport_state |= CMD_T_SENT;
2123
2124                 __target_execute_cmd(cmd, true);
2125
2126                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
2127                         break;
2128         }
2129 }
2130
2131 /*
2132  * Called from I/O completion to determine which dormant/delayed
2133  * and ordered cmds need to have their tasks added to the execution queue.
2134  */
2135 static void transport_complete_task_attr(struct se_cmd *cmd)
2136 {
2137         struct se_device *dev = cmd->se_dev;
2138
2139         if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2140                 return;
2141
2142         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2143                 goto restart;
2144
2145         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2146                 atomic_dec_mb(&dev->simple_cmds);
2147                 dev->dev_cur_ordered_id++;
2148         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2149                 dev->dev_cur_ordered_id++;
2150                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2151                          dev->dev_cur_ordered_id);
2152         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2153                 atomic_dec_mb(&dev->dev_ordered_sync);
2154
2155                 dev->dev_cur_ordered_id++;
2156                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2157                          dev->dev_cur_ordered_id);
2158         }
2159         cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2160
2161 restart:
2162         target_restart_delayed_cmds(dev);
2163 }
2164
2165 static void transport_complete_qf(struct se_cmd *cmd)
2166 {
2167         int ret = 0;
2168
2169         transport_complete_task_attr(cmd);
2170         /*
2171          * If a fabric driver ->write_pending() or ->queue_data_in() callback
2172          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2173          * the same callbacks should not be retried.  Return CHECK_CONDITION
2174          * if a scsi_status is not already set.
2175          *
2176          * If a fabric driver ->queue_status() has returned non zero, always
2177          * keep retrying no matter what..
2178          */
2179         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2180                 if (cmd->scsi_status)
2181                         goto queue_status;
2182
2183                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2184                 goto queue_status;
2185         }
2186
2187         /*
2188          * Check if we need to send a sense buffer from
2189          * the struct se_cmd in question. We do NOT want
2190          * to take this path of the IO has been marked as
2191          * needing to be treated like a "normal read". This
2192          * is the case if it's a tape read, and either the
2193          * FM, EOM, or ILI bits are set, but there is no
2194          * sense data.
2195          */
2196         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2197             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2198                 goto queue_status;
2199
2200         switch (cmd->data_direction) {
2201         case DMA_FROM_DEVICE:
2202                 /* queue status if not treating this as a normal read */
2203                 if (cmd->scsi_status &&
2204                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2205                         goto queue_status;
2206
2207                 trace_target_cmd_complete(cmd);
2208                 ret = cmd->se_tfo->queue_data_in(cmd);
2209                 break;
2210         case DMA_TO_DEVICE:
2211                 if (cmd->se_cmd_flags & SCF_BIDI) {
2212                         ret = cmd->se_tfo->queue_data_in(cmd);
2213                         break;
2214                 }
2215                 fallthrough;
2216         case DMA_NONE:
2217 queue_status:
2218                 trace_target_cmd_complete(cmd);
2219                 ret = cmd->se_tfo->queue_status(cmd);
2220                 break;
2221         default:
2222                 break;
2223         }
2224
2225         if (ret < 0) {
2226                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2227                 return;
2228         }
2229         transport_lun_remove_cmd(cmd);
2230         transport_cmd_check_stop_to_fabric(cmd);
2231 }
2232
2233 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2234                                         int err, bool write_pending)
2235 {
2236         /*
2237          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2238          * ->queue_data_in() callbacks from new process context.
2239          *
2240          * Otherwise for other errors, transport_complete_qf() will send
2241          * CHECK_CONDITION via ->queue_status() instead of attempting to
2242          * retry associated fabric driver data-transfer callbacks.
2243          */
2244         if (err == -EAGAIN || err == -ENOMEM) {
2245                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2246                                                  TRANSPORT_COMPLETE_QF_OK;
2247         } else {
2248                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2249                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2250         }
2251
2252         spin_lock_irq(&dev->qf_cmd_lock);
2253         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2254         atomic_inc_mb(&dev->dev_qf_count);
2255         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2256
2257         schedule_work(&cmd->se_dev->qf_work_queue);
2258 }
2259
2260 static bool target_read_prot_action(struct se_cmd *cmd)
2261 {
2262         switch (cmd->prot_op) {
2263         case TARGET_PROT_DIN_STRIP:
2264                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2265                         u32 sectors = cmd->data_length >>
2266                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2267
2268                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2269                                                      sectors, 0, cmd->t_prot_sg,
2270                                                      0);
2271                         if (cmd->pi_err)
2272                                 return true;
2273                 }
2274                 break;
2275         case TARGET_PROT_DIN_INSERT:
2276                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2277                         break;
2278
2279                 sbc_dif_generate(cmd);
2280                 break;
2281         default:
2282                 break;
2283         }
2284
2285         return false;
2286 }
2287
2288 static void target_complete_ok_work(struct work_struct *work)
2289 {
2290         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2291         int ret;
2292
2293         /*
2294          * Check if we need to move delayed/dormant tasks from cmds on the
2295          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2296          * Attribute.
2297          */
2298         transport_complete_task_attr(cmd);
2299
2300         /*
2301          * Check to schedule QUEUE_FULL work, or execute an existing
2302          * cmd->transport_qf_callback()
2303          */
2304         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2305                 schedule_work(&cmd->se_dev->qf_work_queue);
2306
2307         /*
2308          * Check if we need to send a sense buffer from
2309          * the struct se_cmd in question. We do NOT want
2310          * to take this path of the IO has been marked as
2311          * needing to be treated like a "normal read". This
2312          * is the case if it's a tape read, and either the
2313          * FM, EOM, or ILI bits are set, but there is no
2314          * sense data.
2315          */
2316         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2317             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2318                 WARN_ON(!cmd->scsi_status);
2319                 ret = transport_send_check_condition_and_sense(
2320                                         cmd, 0, 1);
2321                 if (ret)
2322                         goto queue_full;
2323
2324                 transport_lun_remove_cmd(cmd);
2325                 transport_cmd_check_stop_to_fabric(cmd);
2326                 return;
2327         }
2328         /*
2329          * Check for a callback, used by amongst other things
2330          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2331          */
2332         if (cmd->transport_complete_callback) {
2333                 sense_reason_t rc;
2334                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2335                 bool zero_dl = !(cmd->data_length);
2336                 int post_ret = 0;
2337
2338                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2339                 if (!rc && !post_ret) {
2340                         if (caw && zero_dl)
2341                                 goto queue_rsp;
2342
2343                         return;
2344                 } else if (rc) {
2345                         ret = transport_send_check_condition_and_sense(cmd,
2346                                                 rc, 0);
2347                         if (ret)
2348                                 goto queue_full;
2349
2350                         transport_lun_remove_cmd(cmd);
2351                         transport_cmd_check_stop_to_fabric(cmd);
2352                         return;
2353                 }
2354         }
2355
2356 queue_rsp:
2357         switch (cmd->data_direction) {
2358         case DMA_FROM_DEVICE:
2359                 /*
2360                  * if this is a READ-type IO, but SCSI status
2361                  * is set, then skip returning data and just
2362                  * return the status -- unless this IO is marked
2363                  * as needing to be treated as a normal read,
2364                  * in which case we want to go ahead and return
2365                  * the data. This happens, for example, for tape
2366                  * reads with the FM, EOM, or ILI bits set, with
2367                  * no sense data.
2368                  */
2369                 if (cmd->scsi_status &&
2370                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2371                         goto queue_status;
2372
2373                 atomic_long_add(cmd->data_length,
2374                                 &cmd->se_lun->lun_stats.tx_data_octets);
2375                 /*
2376                  * Perform READ_STRIP of PI using software emulation when
2377                  * backend had PI enabled, if the transport will not be
2378                  * performing hardware READ_STRIP offload.
2379                  */
2380                 if (target_read_prot_action(cmd)) {
2381                         ret = transport_send_check_condition_and_sense(cmd,
2382                                                 cmd->pi_err, 0);
2383                         if (ret)
2384                                 goto queue_full;
2385
2386                         transport_lun_remove_cmd(cmd);
2387                         transport_cmd_check_stop_to_fabric(cmd);
2388                         return;
2389                 }
2390
2391                 trace_target_cmd_complete(cmd);
2392                 ret = cmd->se_tfo->queue_data_in(cmd);
2393                 if (ret)
2394                         goto queue_full;
2395                 break;
2396         case DMA_TO_DEVICE:
2397                 atomic_long_add(cmd->data_length,
2398                                 &cmd->se_lun->lun_stats.rx_data_octets);
2399                 /*
2400                  * Check if we need to send READ payload for BIDI-COMMAND
2401                  */
2402                 if (cmd->se_cmd_flags & SCF_BIDI) {
2403                         atomic_long_add(cmd->data_length,
2404                                         &cmd->se_lun->lun_stats.tx_data_octets);
2405                         ret = cmd->se_tfo->queue_data_in(cmd);
2406                         if (ret)
2407                                 goto queue_full;
2408                         break;
2409                 }
2410                 fallthrough;
2411         case DMA_NONE:
2412 queue_status:
2413                 trace_target_cmd_complete(cmd);
2414                 ret = cmd->se_tfo->queue_status(cmd);
2415                 if (ret)
2416                         goto queue_full;
2417                 break;
2418         default:
2419                 break;
2420         }
2421
2422         transport_lun_remove_cmd(cmd);
2423         transport_cmd_check_stop_to_fabric(cmd);
2424         return;
2425
2426 queue_full:
2427         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2428                 " data_direction: %d\n", cmd, cmd->data_direction);
2429
2430         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2431 }
2432
2433 void target_free_sgl(struct scatterlist *sgl, int nents)
2434 {
2435         sgl_free_n_order(sgl, nents, 0);
2436 }
2437 EXPORT_SYMBOL(target_free_sgl);
2438
2439 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2440 {
2441         /*
2442          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2443          * emulation, and free + reset pointers if necessary..
2444          */
2445         if (!cmd->t_data_sg_orig)
2446                 return;
2447
2448         kfree(cmd->t_data_sg);
2449         cmd->t_data_sg = cmd->t_data_sg_orig;
2450         cmd->t_data_sg_orig = NULL;
2451         cmd->t_data_nents = cmd->t_data_nents_orig;
2452         cmd->t_data_nents_orig = 0;
2453 }
2454
2455 static inline void transport_free_pages(struct se_cmd *cmd)
2456 {
2457         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2458                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2459                 cmd->t_prot_sg = NULL;
2460                 cmd->t_prot_nents = 0;
2461         }
2462
2463         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2464                 /*
2465                  * Release special case READ buffer payload required for
2466                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2467                  */
2468                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2469                         target_free_sgl(cmd->t_bidi_data_sg,
2470                                            cmd->t_bidi_data_nents);
2471                         cmd->t_bidi_data_sg = NULL;
2472                         cmd->t_bidi_data_nents = 0;
2473                 }
2474                 transport_reset_sgl_orig(cmd);
2475                 return;
2476         }
2477         transport_reset_sgl_orig(cmd);
2478
2479         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2480         cmd->t_data_sg = NULL;
2481         cmd->t_data_nents = 0;
2482
2483         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2484         cmd->t_bidi_data_sg = NULL;
2485         cmd->t_bidi_data_nents = 0;
2486 }
2487
2488 void *transport_kmap_data_sg(struct se_cmd *cmd)
2489 {
2490         struct scatterlist *sg = cmd->t_data_sg;
2491         struct page **pages;
2492         int i;
2493
2494         /*
2495          * We need to take into account a possible offset here for fabrics like
2496          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2497          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2498          */
2499         if (!cmd->t_data_nents)
2500                 return NULL;
2501
2502         BUG_ON(!sg);
2503         if (cmd->t_data_nents == 1)
2504                 return kmap(sg_page(sg)) + sg->offset;
2505
2506         /* >1 page. use vmap */
2507         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2508         if (!pages)
2509                 return NULL;
2510
2511         /* convert sg[] to pages[] */
2512         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2513                 pages[i] = sg_page(sg);
2514         }
2515
2516         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2517         kfree(pages);
2518         if (!cmd->t_data_vmap)
2519                 return NULL;
2520
2521         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2522 }
2523 EXPORT_SYMBOL(transport_kmap_data_sg);
2524
2525 void transport_kunmap_data_sg(struct se_cmd *cmd)
2526 {
2527         if (!cmd->t_data_nents) {
2528                 return;
2529         } else if (cmd->t_data_nents == 1) {
2530                 kunmap(sg_page(cmd->t_data_sg));
2531                 return;
2532         }
2533
2534         vunmap(cmd->t_data_vmap);
2535         cmd->t_data_vmap = NULL;
2536 }
2537 EXPORT_SYMBOL(transport_kunmap_data_sg);
2538
2539 int
2540 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2541                  bool zero_page, bool chainable)
2542 {
2543         gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
2544
2545         *sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
2546         return *sgl ? 0 : -ENOMEM;
2547 }
2548 EXPORT_SYMBOL(target_alloc_sgl);
2549
2550 /*
2551  * Allocate any required resources to execute the command.  For writes we
2552  * might not have the payload yet, so notify the fabric via a call to
2553  * ->write_pending instead. Otherwise place it on the execution queue.
2554  */
2555 sense_reason_t
2556 transport_generic_new_cmd(struct se_cmd *cmd)
2557 {
2558         unsigned long flags;
2559         int ret = 0;
2560         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2561
2562         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2563             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2564                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2565                                        cmd->prot_length, true, false);
2566                 if (ret < 0)
2567                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2568         }
2569
2570         /*
2571          * Determine if the TCM fabric module has already allocated physical
2572          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2573          * beforehand.
2574          */
2575         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2576             cmd->data_length) {
2577
2578                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2579                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2580                         u32 bidi_length;
2581
2582                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2583                                 bidi_length = cmd->t_task_nolb *
2584                                               cmd->se_dev->dev_attrib.block_size;
2585                         else
2586                                 bidi_length = cmd->data_length;
2587
2588                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2589                                                &cmd->t_bidi_data_nents,
2590                                                bidi_length, zero_flag, false);
2591                         if (ret < 0)
2592                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2593                 }
2594
2595                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2596                                        cmd->data_length, zero_flag, false);
2597                 if (ret < 0)
2598                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2599         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2600                     cmd->data_length) {
2601                 /*
2602                  * Special case for COMPARE_AND_WRITE with fabrics
2603                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2604                  */
2605                 u32 caw_length = cmd->t_task_nolb *
2606                                  cmd->se_dev->dev_attrib.block_size;
2607
2608                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2609                                        &cmd->t_bidi_data_nents,
2610                                        caw_length, zero_flag, false);
2611                 if (ret < 0)
2612                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2613         }
2614         /*
2615          * If this command is not a write we can execute it right here,
2616          * for write buffers we need to notify the fabric driver first
2617          * and let it call back once the write buffers are ready.
2618          */
2619         target_add_to_state_list(cmd);
2620         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2621                 target_execute_cmd(cmd);
2622                 return 0;
2623         }
2624
2625         spin_lock_irqsave(&cmd->t_state_lock, flags);
2626         cmd->t_state = TRANSPORT_WRITE_PENDING;
2627         /*
2628          * Determine if frontend context caller is requesting the stopping of
2629          * this command for frontend exceptions.
2630          */
2631         if (cmd->transport_state & CMD_T_STOP &&
2632             !cmd->se_tfo->write_pending_must_be_called) {
2633                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2634                          __func__, __LINE__, cmd->tag);
2635
2636                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2637
2638                 complete_all(&cmd->t_transport_stop_comp);
2639                 return 0;
2640         }
2641         cmd->transport_state &= ~CMD_T_ACTIVE;
2642         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2643
2644         ret = cmd->se_tfo->write_pending(cmd);
2645         if (ret)
2646                 goto queue_full;
2647
2648         return 0;
2649
2650 queue_full:
2651         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2652         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2653         return 0;
2654 }
2655 EXPORT_SYMBOL(transport_generic_new_cmd);
2656
2657 static void transport_write_pending_qf(struct se_cmd *cmd)
2658 {
2659         unsigned long flags;
2660         int ret;
2661         bool stop;
2662
2663         spin_lock_irqsave(&cmd->t_state_lock, flags);
2664         stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2665         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2666
2667         if (stop) {
2668                 pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2669                         __func__, __LINE__, cmd->tag);
2670                 complete_all(&cmd->t_transport_stop_comp);
2671                 return;
2672         }
2673
2674         ret = cmd->se_tfo->write_pending(cmd);
2675         if (ret) {
2676                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2677                          cmd);
2678                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2679         }
2680 }
2681
2682 static bool
2683 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2684                            unsigned long *flags);
2685
2686 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2687 {
2688         unsigned long flags;
2689
2690         spin_lock_irqsave(&cmd->t_state_lock, flags);
2691         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2692         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2693 }
2694
2695 /*
2696  * Call target_put_sess_cmd() and wait until target_release_cmd_kref(@cmd) has
2697  * finished.
2698  */
2699 void target_put_cmd_and_wait(struct se_cmd *cmd)
2700 {
2701         DECLARE_COMPLETION_ONSTACK(compl);
2702
2703         WARN_ON_ONCE(cmd->abrt_compl);
2704         cmd->abrt_compl = &compl;
2705         target_put_sess_cmd(cmd);
2706         wait_for_completion(&compl);
2707 }
2708
2709 /*
2710  * This function is called by frontend drivers after processing of a command
2711  * has finished.
2712  *
2713  * The protocol for ensuring that either the regular frontend command
2714  * processing flow or target_handle_abort() code drops one reference is as
2715  * follows:
2716  * - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
2717  *   the frontend driver to call this function synchronously or asynchronously.
2718  *   That will cause one reference to be dropped.
2719  * - During regular command processing the target core sets CMD_T_COMPLETE
2720  *   before invoking one of the .queue_*() functions.
2721  * - The code that aborts commands skips commands and TMFs for which
2722  *   CMD_T_COMPLETE has been set.
2723  * - CMD_T_ABORTED is set atomically after the CMD_T_COMPLETE check for
2724  *   commands that will be aborted.
2725  * - If the CMD_T_ABORTED flag is set but CMD_T_TAS has not been set
2726  *   transport_generic_free_cmd() skips its call to target_put_sess_cmd().
2727  * - For aborted commands for which CMD_T_TAS has been set .queue_status() will
2728  *   be called and will drop a reference.
2729  * - For aborted commands for which CMD_T_TAS has not been set .aborted_task()
2730  *   will be called. target_handle_abort() will drop the final reference.
2731  */
2732 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2733 {
2734         DECLARE_COMPLETION_ONSTACK(compl);
2735         int ret = 0;
2736         bool aborted = false, tas = false;
2737
2738         if (wait_for_tasks)
2739                 target_wait_free_cmd(cmd, &aborted, &tas);
2740
2741         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD) {
2742                 /*
2743                  * Handle WRITE failure case where transport_generic_new_cmd()
2744                  * has already added se_cmd to state_list, but fabric has
2745                  * failed command before I/O submission.
2746                  */
2747                 if (cmd->state_active)
2748                         target_remove_from_state_list(cmd);
2749
2750                 if (cmd->se_lun)
2751                         transport_lun_remove_cmd(cmd);
2752         }
2753         if (aborted)
2754                 cmd->free_compl = &compl;
2755         ret = target_put_sess_cmd(cmd);
2756         if (aborted) {
2757                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2758                 wait_for_completion(&compl);
2759                 ret = 1;
2760         }
2761         return ret;
2762 }
2763 EXPORT_SYMBOL(transport_generic_free_cmd);
2764
2765 /**
2766  * target_get_sess_cmd - Verify the session is accepting cmds and take ref
2767  * @se_cmd:     command descriptor to add
2768  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2769  */
2770 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2771 {
2772         struct se_session *se_sess = se_cmd->se_sess;
2773         int ret = 0;
2774
2775         /*
2776          * Add a second kref if the fabric caller is expecting to handle
2777          * fabric acknowledgement that requires two target_put_sess_cmd()
2778          * invocations before se_cmd descriptor release.
2779          */
2780         if (ack_kref) {
2781                 kref_get(&se_cmd->cmd_kref);
2782                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2783         }
2784
2785         if (!percpu_ref_tryget_live(&se_sess->cmd_count))
2786                 ret = -ESHUTDOWN;
2787
2788         if (ret && ack_kref)
2789                 target_put_sess_cmd(se_cmd);
2790
2791         return ret;
2792 }
2793 EXPORT_SYMBOL(target_get_sess_cmd);
2794
2795 static void target_free_cmd_mem(struct se_cmd *cmd)
2796 {
2797         transport_free_pages(cmd);
2798
2799         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2800                 core_tmr_release_req(cmd->se_tmr_req);
2801         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2802                 kfree(cmd->t_task_cdb);
2803 }
2804
2805 static void target_release_cmd_kref(struct kref *kref)
2806 {
2807         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2808         struct se_session *se_sess = se_cmd->se_sess;
2809         struct completion *free_compl = se_cmd->free_compl;
2810         struct completion *abrt_compl = se_cmd->abrt_compl;
2811
2812         target_free_cmd_mem(se_cmd);
2813         se_cmd->se_tfo->release_cmd(se_cmd);
2814         if (free_compl)
2815                 complete(free_compl);
2816         if (abrt_compl)
2817                 complete(abrt_compl);
2818
2819         percpu_ref_put(&se_sess->cmd_count);
2820 }
2821
2822 /**
2823  * target_put_sess_cmd - decrease the command reference count
2824  * @se_cmd:     command to drop a reference from
2825  *
2826  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2827  * refcount to drop to zero. Returns zero otherwise.
2828  */
2829 int target_put_sess_cmd(struct se_cmd *se_cmd)
2830 {
2831         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2832 }
2833 EXPORT_SYMBOL(target_put_sess_cmd);
2834
2835 static const char *data_dir_name(enum dma_data_direction d)
2836 {
2837         switch (d) {
2838         case DMA_BIDIRECTIONAL: return "BIDI";
2839         case DMA_TO_DEVICE:     return "WRITE";
2840         case DMA_FROM_DEVICE:   return "READ";
2841         case DMA_NONE:          return "NONE";
2842         }
2843
2844         return "(?)";
2845 }
2846
2847 static const char *cmd_state_name(enum transport_state_table t)
2848 {
2849         switch (t) {
2850         case TRANSPORT_NO_STATE:        return "NO_STATE";
2851         case TRANSPORT_NEW_CMD:         return "NEW_CMD";
2852         case TRANSPORT_WRITE_PENDING:   return "WRITE_PENDING";
2853         case TRANSPORT_PROCESSING:      return "PROCESSING";
2854         case TRANSPORT_COMPLETE:        return "COMPLETE";
2855         case TRANSPORT_ISTATE_PROCESSING:
2856                                         return "ISTATE_PROCESSING";
2857         case TRANSPORT_COMPLETE_QF_WP:  return "COMPLETE_QF_WP";
2858         case TRANSPORT_COMPLETE_QF_OK:  return "COMPLETE_QF_OK";
2859         case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
2860         }
2861
2862         return "(?)";
2863 }
2864
2865 static void target_append_str(char **str, const char *txt)
2866 {
2867         char *prev = *str;
2868
2869         *str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
2870                 kstrdup(txt, GFP_ATOMIC);
2871         kfree(prev);
2872 }
2873
2874 /*
2875  * Convert a transport state bitmask into a string. The caller is
2876  * responsible for freeing the returned pointer.
2877  */
2878 static char *target_ts_to_str(u32 ts)
2879 {
2880         char *str = NULL;
2881
2882         if (ts & CMD_T_ABORTED)
2883                 target_append_str(&str, "aborted");
2884         if (ts & CMD_T_ACTIVE)
2885                 target_append_str(&str, "active");
2886         if (ts & CMD_T_COMPLETE)
2887                 target_append_str(&str, "complete");
2888         if (ts & CMD_T_SENT)
2889                 target_append_str(&str, "sent");
2890         if (ts & CMD_T_STOP)
2891                 target_append_str(&str, "stop");
2892         if (ts & CMD_T_FABRIC_STOP)
2893                 target_append_str(&str, "fabric_stop");
2894
2895         return str;
2896 }
2897
2898 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
2899 {
2900         switch (tmf) {
2901         case TMR_ABORT_TASK:            return "ABORT_TASK";
2902         case TMR_ABORT_TASK_SET:        return "ABORT_TASK_SET";
2903         case TMR_CLEAR_ACA:             return "CLEAR_ACA";
2904         case TMR_CLEAR_TASK_SET:        return "CLEAR_TASK_SET";
2905         case TMR_LUN_RESET:             return "LUN_RESET";
2906         case TMR_TARGET_WARM_RESET:     return "TARGET_WARM_RESET";
2907         case TMR_TARGET_COLD_RESET:     return "TARGET_COLD_RESET";
2908         case TMR_LUN_RESET_PRO:         return "LUN_RESET_PRO";
2909         case TMR_UNKNOWN:               break;
2910         }
2911         return "(?)";
2912 }
2913
2914 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
2915 {
2916         char *ts_str = target_ts_to_str(cmd->transport_state);
2917         const u8 *cdb = cmd->t_task_cdb;
2918         struct se_tmr_req *tmf = cmd->se_tmr_req;
2919
2920         if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2921                 pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
2922                          pfx, cdb[0], cdb[1], cmd->tag,
2923                          data_dir_name(cmd->data_direction),
2924                          cmd->se_tfo->get_cmd_state(cmd),
2925                          cmd_state_name(cmd->t_state), cmd->data_length,
2926                          kref_read(&cmd->cmd_kref), ts_str);
2927         } else {
2928                 pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
2929                          pfx, target_tmf_name(tmf->function), cmd->tag,
2930                          tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
2931                          cmd_state_name(cmd->t_state),
2932                          kref_read(&cmd->cmd_kref), ts_str);
2933         }
2934         kfree(ts_str);
2935 }
2936 EXPORT_SYMBOL(target_show_cmd);
2937
2938 static void target_stop_session_confirm(struct percpu_ref *ref)
2939 {
2940         struct se_session *se_sess = container_of(ref, struct se_session,
2941                                                   cmd_count);
2942         complete_all(&se_sess->stop_done);
2943 }
2944
2945 /**
2946  * target_stop_session - Stop new IO from being queued on the session.
2947  * @se_sess:    session to stop
2948  */
2949 void target_stop_session(struct se_session *se_sess)
2950 {
2951         pr_debug("Stopping session queue.\n");
2952         if (atomic_cmpxchg(&se_sess->stopped, 0, 1) == 0)
2953                 percpu_ref_kill_and_confirm(&se_sess->cmd_count,
2954                                             target_stop_session_confirm);
2955 }
2956 EXPORT_SYMBOL(target_stop_session);
2957
2958 /**
2959  * target_wait_for_sess_cmds - Wait for outstanding commands
2960  * @se_sess:    session to wait for active I/O
2961  */
2962 void target_wait_for_sess_cmds(struct se_session *se_sess)
2963 {
2964         int ret;
2965
2966         WARN_ON_ONCE(!atomic_read(&se_sess->stopped));
2967
2968         do {
2969                 pr_debug("Waiting for running cmds to complete.\n");
2970                 ret = wait_event_timeout(se_sess->cmd_count_wq,
2971                                 percpu_ref_is_zero(&se_sess->cmd_count),
2972                                 180 * HZ);
2973         } while (ret <= 0);
2974
2975         wait_for_completion(&se_sess->stop_done);
2976         pr_debug("Waiting for cmds done.\n");
2977 }
2978 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2979
2980 /*
2981  * Prevent that new percpu_ref_tryget_live() calls succeed and wait until
2982  * all references to the LUN have been released. Called during LUN shutdown.
2983  */
2984 void transport_clear_lun_ref(struct se_lun *lun)
2985 {
2986         percpu_ref_kill(&lun->lun_ref);
2987         wait_for_completion(&lun->lun_shutdown_comp);
2988 }
2989
2990 static bool
2991 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2992                            bool *aborted, bool *tas, unsigned long *flags)
2993         __releases(&cmd->t_state_lock)
2994         __acquires(&cmd->t_state_lock)
2995 {
2996
2997         assert_spin_locked(&cmd->t_state_lock);
2998         WARN_ON_ONCE(!irqs_disabled());
2999
3000         if (fabric_stop)
3001                 cmd->transport_state |= CMD_T_FABRIC_STOP;
3002
3003         if (cmd->transport_state & CMD_T_ABORTED)
3004                 *aborted = true;
3005
3006         if (cmd->transport_state & CMD_T_TAS)
3007                 *tas = true;
3008
3009         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
3010             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3011                 return false;
3012
3013         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
3014             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3015                 return false;
3016
3017         if (!(cmd->transport_state & CMD_T_ACTIVE))
3018                 return false;
3019
3020         if (fabric_stop && *aborted)
3021                 return false;
3022
3023         cmd->transport_state |= CMD_T_STOP;
3024
3025         target_show_cmd("wait_for_tasks: Stopping ", cmd);
3026
3027         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
3028
3029         while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
3030                                             180 * HZ))
3031                 target_show_cmd("wait for tasks: ", cmd);
3032
3033         spin_lock_irqsave(&cmd->t_state_lock, *flags);
3034         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
3035
3036         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
3037                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
3038
3039         return true;
3040 }
3041
3042 /**
3043  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3044  * @cmd: command to wait on
3045  */
3046 bool transport_wait_for_tasks(struct se_cmd *cmd)
3047 {
3048         unsigned long flags;
3049         bool ret, aborted = false, tas = false;
3050
3051         spin_lock_irqsave(&cmd->t_state_lock, flags);
3052         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3053         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3054
3055         return ret;
3056 }
3057 EXPORT_SYMBOL(transport_wait_for_tasks);
3058
3059 struct sense_detail {
3060         u8 key;
3061         u8 asc;
3062         u8 ascq;
3063         bool add_sense_info;
3064 };
3065
3066 static const struct sense_detail sense_detail_table[] = {
3067         [TCM_NO_SENSE] = {
3068                 .key = NOT_READY
3069         },
3070         [TCM_NON_EXISTENT_LUN] = {
3071                 .key = ILLEGAL_REQUEST,
3072                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3073         },
3074         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
3075                 .key = ILLEGAL_REQUEST,
3076                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3077         },
3078         [TCM_SECTOR_COUNT_TOO_MANY] = {
3079                 .key = ILLEGAL_REQUEST,
3080                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3081         },
3082         [TCM_UNKNOWN_MODE_PAGE] = {
3083                 .key = ILLEGAL_REQUEST,
3084                 .asc = 0x24, /* INVALID FIELD IN CDB */
3085         },
3086         [TCM_CHECK_CONDITION_ABORT_CMD] = {
3087                 .key = ABORTED_COMMAND,
3088                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3089                 .ascq = 0x03,
3090         },
3091         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
3092                 .key = ABORTED_COMMAND,
3093                 .asc = 0x0c, /* WRITE ERROR */
3094                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3095         },
3096         [TCM_INVALID_CDB_FIELD] = {
3097                 .key = ILLEGAL_REQUEST,
3098                 .asc = 0x24, /* INVALID FIELD IN CDB */
3099         },
3100         [TCM_INVALID_PARAMETER_LIST] = {
3101                 .key = ILLEGAL_REQUEST,
3102                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3103         },
3104         [TCM_TOO_MANY_TARGET_DESCS] = {
3105                 .key = ILLEGAL_REQUEST,
3106                 .asc = 0x26,
3107                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3108         },
3109         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3110                 .key = ILLEGAL_REQUEST,
3111                 .asc = 0x26,
3112                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3113         },
3114         [TCM_TOO_MANY_SEGMENT_DESCS] = {
3115                 .key = ILLEGAL_REQUEST,
3116                 .asc = 0x26,
3117                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3118         },
3119         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3120                 .key = ILLEGAL_REQUEST,
3121                 .asc = 0x26,
3122                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3123         },
3124         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3125                 .key = ILLEGAL_REQUEST,
3126                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3127         },
3128         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3129                 .key = ILLEGAL_REQUEST,
3130                 .asc = 0x0c, /* WRITE ERROR */
3131                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3132         },
3133         [TCM_SERVICE_CRC_ERROR] = {
3134                 .key = ABORTED_COMMAND,
3135                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3136                 .ascq = 0x05, /* N/A */
3137         },
3138         [TCM_SNACK_REJECTED] = {
3139                 .key = ABORTED_COMMAND,
3140                 .asc = 0x11, /* READ ERROR */
3141                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3142         },
3143         [TCM_WRITE_PROTECTED] = {
3144                 .key = DATA_PROTECT,
3145                 .asc = 0x27, /* WRITE PROTECTED */
3146         },
3147         [TCM_ADDRESS_OUT_OF_RANGE] = {
3148                 .key = ILLEGAL_REQUEST,
3149                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3150         },
3151         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3152                 .key = UNIT_ATTENTION,
3153         },
3154         [TCM_CHECK_CONDITION_NOT_READY] = {
3155                 .key = NOT_READY,
3156         },
3157         [TCM_MISCOMPARE_VERIFY] = {
3158                 .key = MISCOMPARE,
3159                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3160                 .ascq = 0x00,
3161                 .add_sense_info = true,
3162         },
3163         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3164                 .key = ABORTED_COMMAND,
3165                 .asc = 0x10,
3166                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3167                 .add_sense_info = true,
3168         },
3169         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3170                 .key = ABORTED_COMMAND,
3171                 .asc = 0x10,
3172                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3173                 .add_sense_info = true,
3174         },
3175         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3176                 .key = ABORTED_COMMAND,
3177                 .asc = 0x10,
3178                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3179                 .add_sense_info = true,
3180         },
3181         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3182                 .key = COPY_ABORTED,
3183                 .asc = 0x0d,
3184                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3185
3186         },
3187         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3188                 /*
3189                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
3190                  * Solaris initiators.  Returning NOT READY instead means the
3191                  * operations will be retried a finite number of times and we
3192                  * can survive intermittent errors.
3193                  */
3194                 .key = NOT_READY,
3195                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3196         },
3197         [TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3198                 /*
3199                  * From spc4r22 section5.7.7,5.7.8
3200                  * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3201                  * or a REGISTER AND IGNORE EXISTING KEY service action or
3202                  * REGISTER AND MOVE service actionis attempted,
3203                  * but there are insufficient device server resources to complete the
3204                  * operation, then the command shall be terminated with CHECK CONDITION
3205                  * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3206                  * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3207                  */
3208                 .key = ILLEGAL_REQUEST,
3209                 .asc = 0x55,
3210                 .ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3211         },
3212         [TCM_INVALID_FIELD_IN_COMMAND_IU] = {
3213                 .key = ILLEGAL_REQUEST,
3214                 .asc = 0x0e,
3215                 .ascq = 0x03, /* INVALID FIELD IN COMMAND INFORMATION UNIT */
3216         },
3217 };
3218
3219 /**
3220  * translate_sense_reason - translate a sense reason into T10 key, asc and ascq
3221  * @cmd: SCSI command in which the resulting sense buffer or SCSI status will
3222  *   be stored.
3223  * @reason: LIO sense reason code. If this argument has the value
3224  *   TCM_CHECK_CONDITION_UNIT_ATTENTION, try to dequeue a unit attention. If
3225  *   dequeuing a unit attention fails due to multiple commands being processed
3226  *   concurrently, set the command status to BUSY.
3227  *
3228  * Return: 0 upon success or -EINVAL if the sense buffer is too small.
3229  */
3230 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3231 {
3232         const struct sense_detail *sd;
3233         u8 *buffer = cmd->sense_buffer;
3234         int r = (__force int)reason;
3235         u8 key, asc, ascq;
3236         bool desc_format = target_sense_desc_format(cmd->se_dev);
3237
3238         if (r < ARRAY_SIZE(sense_detail_table) && sense_detail_table[r].key)
3239                 sd = &sense_detail_table[r];
3240         else
3241                 sd = &sense_detail_table[(__force int)
3242                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3243
3244         key = sd->key;
3245         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3246                 if (!core_scsi3_ua_for_check_condition(cmd, &key, &asc,
3247                                                        &ascq)) {
3248                         cmd->scsi_status = SAM_STAT_BUSY;
3249                         return;
3250                 }
3251         } else if (sd->asc == 0) {
3252                 WARN_ON_ONCE(cmd->scsi_asc == 0);
3253                 asc = cmd->scsi_asc;
3254                 ascq = cmd->scsi_ascq;
3255         } else {
3256                 asc = sd->asc;
3257                 ascq = sd->ascq;
3258         }
3259
3260         cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3261         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3262         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3263         scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
3264         if (sd->add_sense_info)
3265                 WARN_ON_ONCE(scsi_set_sense_information(buffer,
3266                                                         cmd->scsi_sense_length,
3267                                                         cmd->sense_info) < 0);
3268 }
3269
3270 int
3271 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3272                 sense_reason_t reason, int from_transport)
3273 {
3274         unsigned long flags;
3275
3276         WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3277
3278         spin_lock_irqsave(&cmd->t_state_lock, flags);
3279         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3280                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3281                 return 0;
3282         }
3283         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3284         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3285
3286         if (!from_transport)
3287                 translate_sense_reason(cmd, reason);
3288
3289         trace_target_cmd_complete(cmd);
3290         return cmd->se_tfo->queue_status(cmd);
3291 }
3292 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3293
3294 /**
3295  * target_send_busy - Send SCSI BUSY status back to the initiator
3296  * @cmd: SCSI command for which to send a BUSY reply.
3297  *
3298  * Note: Only call this function if target_submit_cmd*() failed.
3299  */
3300 int target_send_busy(struct se_cmd *cmd)
3301 {
3302         WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3303
3304         cmd->scsi_status = SAM_STAT_BUSY;
3305         trace_target_cmd_complete(cmd);
3306         return cmd->se_tfo->queue_status(cmd);
3307 }
3308 EXPORT_SYMBOL(target_send_busy);
3309
3310 static void target_tmr_work(struct work_struct *work)
3311 {
3312         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3313         struct se_device *dev = cmd->se_dev;
3314         struct se_tmr_req *tmr = cmd->se_tmr_req;
3315         int ret;
3316
3317         if (cmd->transport_state & CMD_T_ABORTED)
3318                 goto aborted;
3319
3320         switch (tmr->function) {
3321         case TMR_ABORT_TASK:
3322                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3323                 break;
3324         case TMR_ABORT_TASK_SET:
3325         case TMR_CLEAR_ACA:
3326         case TMR_CLEAR_TASK_SET:
3327                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3328                 break;
3329         case TMR_LUN_RESET:
3330                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3331                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3332                                          TMR_FUNCTION_REJECTED;
3333                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3334                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3335                                                cmd->orig_fe_lun, 0x29,
3336                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3337                 }
3338                 break;
3339         case TMR_TARGET_WARM_RESET:
3340                 tmr->response = TMR_FUNCTION_REJECTED;
3341                 break;
3342         case TMR_TARGET_COLD_RESET:
3343                 tmr->response = TMR_FUNCTION_REJECTED;
3344                 break;
3345         default:
3346                 pr_err("Unknown TMR function: 0x%02x.\n",
3347                                 tmr->function);
3348                 tmr->response = TMR_FUNCTION_REJECTED;
3349                 break;
3350         }
3351
3352         if (cmd->transport_state & CMD_T_ABORTED)
3353                 goto aborted;
3354
3355         cmd->se_tfo->queue_tm_rsp(cmd);
3356
3357         transport_lun_remove_cmd(cmd);
3358         transport_cmd_check_stop_to_fabric(cmd);
3359         return;
3360
3361 aborted:
3362         target_handle_abort(cmd);
3363 }
3364
3365 int transport_generic_handle_tmr(
3366         struct se_cmd *cmd)
3367 {
3368         unsigned long flags;
3369         bool aborted = false;
3370
3371         spin_lock_irqsave(&cmd->t_state_lock, flags);
3372         if (cmd->transport_state & CMD_T_ABORTED) {
3373                 aborted = true;
3374         } else {
3375                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3376                 cmd->transport_state |= CMD_T_ACTIVE;
3377         }
3378         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3379
3380         if (aborted) {
3381                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d ref_tag: %llu tag: %llu\n",
3382                                     cmd->se_tmr_req->function,
3383                                     cmd->se_tmr_req->ref_task_tag, cmd->tag);
3384                 target_handle_abort(cmd);
3385                 return 0;
3386         }
3387
3388         INIT_WORK(&cmd->work, target_tmr_work);
3389         schedule_work(&cmd->work);
3390         return 0;
3391 }
3392 EXPORT_SYMBOL(transport_generic_handle_tmr);
3393
3394 bool
3395 target_check_wce(struct se_device *dev)
3396 {
3397         bool wce = false;
3398
3399         if (dev->transport->get_write_cache)
3400                 wce = dev->transport->get_write_cache(dev);
3401         else if (dev->dev_attrib.emulate_write_cache > 0)
3402                 wce = true;
3403
3404         return wce;
3405 }
3406
3407 bool
3408 target_check_fua(struct se_device *dev)
3409 {
3410         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3411 }