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