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