drivers/target/target_core_transport.c

   1 /*******************************************************************************
   2  * Filename:  target_core_transport.c
   3  *
   4  * This file contains the Generic Target Engine Core.
   5  *
   6  * (c) Copyright 2002-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/net.h>
  27 #include <linux/delay.h>
  28 #include <linux/string.h>
  29 #include <linux/timer.h>
  30 #include <linux/slab.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/kthread.h>
  33 #include <linux/in.h>
  34 #include <linux/cdrom.h>
  35 #include <linux/module.h>
  36 #include <linux/ratelimit.h>
  37 #include <linux/vmalloc.h>
  38 #include <asm/unaligned.h>
  39 #include <net/sock.h>
  40 #include <net/tcp.h>
  41 #include <scsi/scsi_proto.h>
  42 #include <scsi/scsi_common.h>
  43
  44 #include <target/target_core_base.h>
  45 #include <target/target_core_backend.h>
  46 #include <target/target_core_fabric.h>
  47
  48 #include "target_core_internal.h"
  49 #include "target_core_alua.h"
  50 #include "target_core_pr.h"
  51 #include "target_core_ua.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/target.h>
  55
  56 static struct workqueue_struct *target_completion_wq;
  57 static struct kmem_cache *se_sess_cache;
  58 struct kmem_cache *se_ua_cache;
  59 struct kmem_cache *t10_pr_reg_cache;
  60 struct kmem_cache *t10_alua_lu_gp_cache;
  61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  63 struct kmem_cache *t10_alua_lba_map_cache;
  64 struct kmem_cache *t10_alua_lba_map_mem_cache;
  65
  66 static void transport_complete_task_attr(struct se_cmd *cmd);
  67 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
  68 static void transport_handle_queue_full(struct se_cmd *cmd,
  69                 struct se_device *dev, int err, bool write_pending);
  70 static int transport_put_cmd(struct se_cmd *cmd);
  71 static void target_complete_ok_work(struct work_struct *work);
  72
  73 int init_se_kmem_caches(void)
  74 {
  75         se_sess_cache = kmem_cache_create("se_sess_cache",
  76                         sizeof(struct se_session), __alignof__(struct se_session),
  77                         0, NULL);
  78         if (!se_sess_cache) {
  79                 pr_err("kmem_cache_create() for struct se_session"
  80                                 " failed\n");
  81                 goto out;
  82         }
  83         se_ua_cache = kmem_cache_create("se_ua_cache",
  84                         sizeof(struct se_ua), __alignof__(struct se_ua),
  85                         0, NULL);
  86         if (!se_ua_cache) {
  87                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  88                 goto out_free_sess_cache;
  89         }
  90         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  91                         sizeof(struct t10_pr_registration),
  92                         __alignof__(struct t10_pr_registration), 0, NULL);
  93         if (!t10_pr_reg_cache) {
  94                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  95                                 " failed\n");
  96                 goto out_free_ua_cache;
  97         }
  98         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  99                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
 100                         0, NULL);
 101         if (!t10_alua_lu_gp_cache) {
 102                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 103                                 " failed\n");
 104                 goto out_free_pr_reg_cache;
 105         }
 106         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 107                         sizeof(struct t10_alua_lu_gp_member),
 108                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 109         if (!t10_alua_lu_gp_mem_cache) {
 110                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 111                                 "cache failed\n");
 112                 goto out_free_lu_gp_cache;
 113         }
 114         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 115                         sizeof(struct t10_alua_tg_pt_gp),
 116                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 117         if (!t10_alua_tg_pt_gp_cache) {
 118                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 119                                 "cache failed\n");
 120                 goto out_free_lu_gp_mem_cache;
 121         }
 122         t10_alua_lba_map_cache = kmem_cache_create(
 123                         "t10_alua_lba_map_cache",
 124                         sizeof(struct t10_alua_lba_map),
 125                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 126         if (!t10_alua_lba_map_cache) {
 127                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 128                                 "cache failed\n");
 129                 goto out_free_tg_pt_gp_cache;
 130         }
 131         t10_alua_lba_map_mem_cache = kmem_cache_create(
 132                         "t10_alua_lba_map_mem_cache",
 133                         sizeof(struct t10_alua_lba_map_member),
 134                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 135         if (!t10_alua_lba_map_mem_cache) {
 136                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 137                                 "cache failed\n");
 138                 goto out_free_lba_map_cache;
 139         }
 140
 141         target_completion_wq = alloc_workqueue("target_completion",
 142                                                WQ_MEM_RECLAIM, 0);
 143         if (!target_completion_wq)
 144                 goto out_free_lba_map_mem_cache;
 145
 146         return 0;
 147
 148 out_free_lba_map_mem_cache:
 149         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 150 out_free_lba_map_cache:
 151         kmem_cache_destroy(t10_alua_lba_map_cache);
 152 out_free_tg_pt_gp_cache:
 153         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 154 out_free_lu_gp_mem_cache:
 155         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 156 out_free_lu_gp_cache:
 157         kmem_cache_destroy(t10_alua_lu_gp_cache);
 158 out_free_pr_reg_cache:
 159         kmem_cache_destroy(t10_pr_reg_cache);
 160 out_free_ua_cache:
 161         kmem_cache_destroy(se_ua_cache);
 162 out_free_sess_cache:
 163         kmem_cache_destroy(se_sess_cache);
 164 out:
 165         return -ENOMEM;
 166 }
 167
 168 void release_se_kmem_caches(void)
 169 {
 170         destroy_workqueue(target_completion_wq);
 171         kmem_cache_destroy(se_sess_cache);
 172         kmem_cache_destroy(se_ua_cache);
 173         kmem_cache_destroy(t10_pr_reg_cache);
 174         kmem_cache_destroy(t10_alua_lu_gp_cache);
 175         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 176         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 177         kmem_cache_destroy(t10_alua_lba_map_cache);
 178         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 179 }
 180
 181 /* This code ensures unique mib indexes are handed out. */
 182 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 183 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 184
 185 /*
 186  * Allocate a new row index for the entry type specified
 187  */
 188 u32 scsi_get_new_index(scsi_index_t type)
 189 {
 190         u32 new_index;
 191
 192         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 193
 194         spin_lock(&scsi_mib_index_lock);
 195         new_index = ++scsi_mib_index[type];
 196         spin_unlock(&scsi_mib_index_lock);
 197
 198         return new_index;
 199 }
 200
 201 void transport_subsystem_check_init(void)
 202 {
 203         int ret;
 204         static int sub_api_initialized;
 205
 206         if (sub_api_initialized)
 207                 return;
 208
 209         ret = request_module("target_core_iblock");
 210         if (ret != 0)
 211                 pr_err("Unable to load target_core_iblock\n");
 212
 213         ret = request_module("target_core_file");
 214         if (ret != 0)
 215                 pr_err("Unable to load target_core_file\n");
 216
 217         ret = request_module("target_core_pscsi");
 218         if (ret != 0)
 219                 pr_err("Unable to load target_core_pscsi\n");
 220
 221         ret = request_module("target_core_user");
 222         if (ret != 0)
 223                 pr_err("Unable to load target_core_user\n");
 224
 225         sub_api_initialized = 1;
 226 }
 227
 228 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
 229 {
 230         struct se_session *se_sess;
 231
 232         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 233         if (!se_sess) {
 234                 pr_err("Unable to allocate struct se_session from"
 235                                 " se_sess_cache\n");
 236                 return ERR_PTR(-ENOMEM);
 237         }
 238         INIT_LIST_HEAD(&se_sess->sess_list);
 239         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 240         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 241         INIT_LIST_HEAD(&se_sess->sess_wait_list);
 242         spin_lock_init(&se_sess->sess_cmd_lock);
 243         se_sess->sup_prot_ops = sup_prot_ops;
 244
 245         return se_sess;
 246 }
 247 EXPORT_SYMBOL(transport_init_session);
 248
 249 int transport_alloc_session_tags(struct se_session *se_sess,
 250                                  unsigned int tag_num, unsigned int tag_size)
 251 {
 252         int rc;
 253
 254         se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
 255                                         GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);
 256         if (!se_sess->sess_cmd_map) {
 257                 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
 258                 if (!se_sess->sess_cmd_map) {
 259                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 260                         return -ENOMEM;
 261                 }
 262         }
 263
 264         rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
 265         if (rc < 0) {
 266                 pr_err("Unable to init se_sess->sess_tag_pool,"
 267                         " tag_num: %u\n", tag_num);
 268                 kvfree(se_sess->sess_cmd_map);
 269                 se_sess->sess_cmd_map = NULL;
 270                 return -ENOMEM;
 271         }
 272
 273         return 0;
 274 }
 275 EXPORT_SYMBOL(transport_alloc_session_tags);
 276
 277 struct se_session *transport_init_session_tags(unsigned int tag_num,
 278                                                unsigned int tag_size,
 279                                                enum target_prot_op sup_prot_ops)
 280 {
 281         struct se_session *se_sess;
 282         int rc;
 283
 284         if (tag_num != 0 && !tag_size) {
 285                 pr_err("init_session_tags called with percpu-ida tag_num:"
 286                        " %u, but zero tag_size\n", tag_num);
 287                 return ERR_PTR(-EINVAL);
 288         }
 289         if (!tag_num && tag_size) {
 290                 pr_err("init_session_tags called with percpu-ida tag_size:"
 291                        " %u, but zero tag_num\n", tag_size);
 292                 return ERR_PTR(-EINVAL);
 293         }
 294
 295         se_sess = transport_init_session(sup_prot_ops);
 296         if (IS_ERR(se_sess))
 297                 return se_sess;
 298
 299         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 300         if (rc < 0) {
 301                 transport_free_session(se_sess);
 302                 return ERR_PTR(-ENOMEM);
 303         }
 304
 305         return se_sess;
 306 }
 307 EXPORT_SYMBOL(transport_init_session_tags);
 308
 309 /*
 310  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 311  */
 312 void __transport_register_session(
 313         struct se_portal_group *se_tpg,
 314         struct se_node_acl *se_nacl,
 315         struct se_session *se_sess,
 316         void *fabric_sess_ptr)
 317 {
 318         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 319         unsigned char buf[PR_REG_ISID_LEN];
 320
 321         se_sess->se_tpg = se_tpg;
 322         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 323         /*
 324          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 325          *
 326          * Only set for struct se_session's that will actually be moving I/O.
 327          * eg: *NOT* discovery sessions.
 328          */
 329         if (se_nacl) {
 330                 /*
 331                  *
 332                  * Determine if fabric allows for T10-PI feature bits exposed to
 333                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 334                  *
 335                  * If so, then always save prot_type on a per se_node_acl node
 336                  * basis and re-instate the previous sess_prot_type to avoid
 337                  * disabling PI from below any previously initiator side
 338                  * registered LUNs.
 339                  */
 340                 if (se_nacl->saved_prot_type)
 341                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 342                 else if (tfo->tpg_check_prot_fabric_only)
 343                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 344                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 345                 /*
 346                  * If the fabric module supports an ISID based TransportID,
 347                  * save this value in binary from the fabric I_T Nexus now.
 348                  */
 349                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 350                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 351                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 352                                         &buf[0], PR_REG_ISID_LEN);
 353                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 354                 }
 355
 356                 spin_lock_irq(&se_nacl->nacl_sess_lock);
 357                 /*
 358                  * The se_nacl->nacl_sess pointer will be set to the
 359                  * last active I_T Nexus for each struct se_node_acl.
 360                  */
 361                 se_nacl->nacl_sess = se_sess;
 362
 363                 list_add_tail(&se_sess->sess_acl_list,
 364                               &se_nacl->acl_sess_list);
 365                 spin_unlock_irq(&se_nacl->nacl_sess_lock);
 366         }
 367         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 368
 369         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 370                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 371 }
 372 EXPORT_SYMBOL(__transport_register_session);
 373
 374 void transport_register_session(
 375         struct se_portal_group *se_tpg,
 376         struct se_node_acl *se_nacl,
 377         struct se_session *se_sess,
 378         void *fabric_sess_ptr)
 379 {
 380         unsigned long flags;
 381
 382         spin_lock_irqsave(&se_tpg->session_lock, flags);
 383         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 384         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 385 }
 386 EXPORT_SYMBOL(transport_register_session);
 387
 388 struct se_session *
 389 target_alloc_session(struct se_portal_group *tpg,
 390                      unsigned int tag_num, unsigned int tag_size,
 391                      enum target_prot_op prot_op,
 392                      const char *initiatorname, void *private,
 393                      int (*callback)(struct se_portal_group *,
 394                                      struct se_session *, void *))
 395 {
 396         struct se_session *sess;
 397
 398         /*
 399          * If the fabric driver is using percpu-ida based pre allocation
 400          * of I/O descriptor tags, go ahead and perform that setup now..
 401          */
 402         if (tag_num != 0)
 403                 sess = transport_init_session_tags(tag_num, tag_size, prot_op);
 404         else
 405                 sess = transport_init_session(prot_op);
 406
 407         if (IS_ERR(sess))
 408                 return sess;
 409
 410         sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
 411                                         (unsigned char *)initiatorname);
 412         if (!sess->se_node_acl) {
 413                 transport_free_session(sess);
 414                 return ERR_PTR(-EACCES);
 415         }
 416         /*
 417          * Go ahead and perform any remaining fabric setup that is
 418          * required before transport_register_session().
 419          */
 420         if (callback != NULL) {
 421                 int rc = callback(tpg, sess, private);
 422                 if (rc) {
 423                         transport_free_session(sess);
 424                         return ERR_PTR(rc);
 425                 }
 426         }
 427
 428         transport_register_session(tpg, sess->se_node_acl, sess, private);
 429         return sess;
 430 }
 431 EXPORT_SYMBOL(target_alloc_session);
 432
 433 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 434 {
 435         struct se_session *se_sess;
 436         ssize_t len = 0;
 437
 438         spin_lock_bh(&se_tpg->session_lock);
 439         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 440                 if (!se_sess->se_node_acl)
 441                         continue;
 442                 if (!se_sess->se_node_acl->dynamic_node_acl)
 443                         continue;
 444                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 445                         break;
 446
 447                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 448                                 se_sess->se_node_acl->initiatorname);
 449                 len += 1; /* Include NULL terminator */
 450         }
 451         spin_unlock_bh(&se_tpg->session_lock);
 452
 453         return len;
 454 }
 455 EXPORT_SYMBOL(target_show_dynamic_sessions);
 456
 457 static void target_complete_nacl(struct kref *kref)
 458 {
 459         struct se_node_acl *nacl = container_of(kref,
 460                                 struct se_node_acl, acl_kref);
 461         struct se_portal_group *se_tpg = nacl->se_tpg;
 462
 463         if (!nacl->dynamic_stop) {
 464                 complete(&nacl->acl_free_comp);
 465                 return;
 466         }
 467
 468         mutex_lock(&se_tpg->acl_node_mutex);
 469         list_del_init(&nacl->acl_list);
 470         mutex_unlock(&se_tpg->acl_node_mutex);
 471
 472         core_tpg_wait_for_nacl_pr_ref(nacl);
 473         core_free_device_list_for_node(nacl, se_tpg);
 474         kfree(nacl);
 475 }
 476
 477 void target_put_nacl(struct se_node_acl *nacl)
 478 {
 479         kref_put(&nacl->acl_kref, target_complete_nacl);
 480 }
 481 EXPORT_SYMBOL(target_put_nacl);
 482
 483 void transport_deregister_session_configfs(struct se_session *se_sess)
 484 {
 485         struct se_node_acl *se_nacl;
 486         unsigned long flags;
 487         /*
 488          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 489          */
 490         se_nacl = se_sess->se_node_acl;
 491         if (se_nacl) {
 492                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 493                 if (!list_empty(&se_sess->sess_acl_list))
 494                         list_del_init(&se_sess->sess_acl_list);
 495                 /*
 496                  * If the session list is empty, then clear the pointer.
 497                  * Otherwise, set the struct se_session pointer from the tail
 498                  * element of the per struct se_node_acl active session list.
 499                  */
 500                 if (list_empty(&se_nacl->acl_sess_list))
 501                         se_nacl->nacl_sess = NULL;
 502                 else {
 503                         se_nacl->nacl_sess = container_of(
 504                                         se_nacl->acl_sess_list.prev,
 505                                         struct se_session, sess_acl_list);
 506                 }
 507                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 508         }
 509 }
 510 EXPORT_SYMBOL(transport_deregister_session_configfs);
 511
 512 void transport_free_session(struct se_session *se_sess)
 513 {
 514         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 515
 516         /*
 517          * Drop the se_node_acl->nacl_kref obtained from within
 518          * core_tpg_get_initiator_node_acl().
 519          */
 520         if (se_nacl) {
 521                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 522                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 523                 unsigned long flags;
 524
 525                 se_sess->se_node_acl = NULL;
 526
 527                 /*
 528                  * Also determine if we need to drop the extra ->cmd_kref if
 529                  * it had been previously dynamically generated, and
 530                  * the endpoint is not caching dynamic ACLs.
 531                  */
 532                 mutex_lock(&se_tpg->acl_node_mutex);
 533                 if (se_nacl->dynamic_node_acl &&
 534                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 535                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 536                         if (list_empty(&se_nacl->acl_sess_list))
 537                                 se_nacl->dynamic_stop = true;
 538                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 539
 540                         if (se_nacl->dynamic_stop)
 541                                 list_del_init(&se_nacl->acl_list);
 542                 }
 543                 mutex_unlock(&se_tpg->acl_node_mutex);
 544
 545                 if (se_nacl->dynamic_stop)
 546                         target_put_nacl(se_nacl);
 547
 548                 target_put_nacl(se_nacl);
 549         }
 550         if (se_sess->sess_cmd_map) {
 551                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 552                 kvfree(se_sess->sess_cmd_map);
 553         }
 554         kmem_cache_free(se_sess_cache, se_sess);
 555 }
 556 EXPORT_SYMBOL(transport_free_session);
 557
 558 void transport_deregister_session(struct se_session *se_sess)
 559 {
 560         struct se_portal_group *se_tpg = se_sess->se_tpg;
 561         unsigned long flags;
 562
 563         if (!se_tpg) {
 564                 transport_free_session(se_sess);
 565                 return;
 566         }
 567
 568         spin_lock_irqsave(&se_tpg->session_lock, flags);
 569         list_del(&se_sess->sess_list);
 570         se_sess->se_tpg = NULL;
 571         se_sess->fabric_sess_ptr = NULL;
 572         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 573
 574         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 575                 se_tpg->se_tpg_tfo->get_fabric_name());
 576         /*
 577          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 578          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 579          * removal context from within transport_free_session() code.
 580          *
 581          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 582          * to release all remaining generate_node_acl=1 created ACL resources.
 583          */
 584
 585         transport_free_session(se_sess);
 586 }
 587 EXPORT_SYMBOL(transport_deregister_session);
 588
 589 static void target_remove_from_state_list(struct se_cmd *cmd)
 590 {
 591         struct se_device *dev = cmd->se_dev;
 592         unsigned long flags;
 593
 594         if (!dev)
 595                 return;
 596
 597         spin_lock_irqsave(&dev->execute_task_lock, flags);
 598         if (cmd->state_active) {
 599                 list_del(&cmd->state_list);
 600                 cmd->state_active = false;
 601         }
 602         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 603 }
 604
 605 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 606 {
 607         unsigned long flags;
 608
 609         target_remove_from_state_list(cmd);
 610
 611         /*
 612          * Clear struct se_cmd->se_lun before the handoff to FE.
 613          */
 614         cmd->se_lun = NULL;
 615
 616         spin_lock_irqsave(&cmd->t_state_lock, flags);
 617         /*
 618          * Determine if frontend context caller is requesting the stopping of
 619          * this command for frontend exceptions.
 620          */
 621         if (cmd->transport_state & CMD_T_STOP) {
 622                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 623                         __func__, __LINE__, cmd->tag);
 624
 625                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 626
 627                 complete_all(&cmd->t_transport_stop_comp);
 628                 return 1;
 629         }
 630         cmd->transport_state &= ~CMD_T_ACTIVE;
 631         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 632
 633         /*
 634          * Some fabric modules like tcm_loop can release their internally
 635          * allocated I/O reference and struct se_cmd now.
 636          *
 637          * Fabric modules are expected to return '1' here if the se_cmd being
 638          * passed is released at this point, or zero if not being released.
 639          */
 640         return cmd->se_tfo->check_stop_free(cmd);
 641 }
 642
 643 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 644 {
 645         struct se_lun *lun = cmd->se_lun;
 646
 647         if (!lun)
 648                 return;
 649
 650         if (cmpxchg(&cmd->lun_ref_active, true, false))
 651                 percpu_ref_put(&lun->lun_ref);
 652 }
 653
 654 int transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 655 {
 656         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 657         int ret = 0;
 658
 659         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 660                 transport_lun_remove_cmd(cmd);
 661         /*
 662          * Allow the fabric driver to unmap any resources before
 663          * releasing the descriptor via TFO->release_cmd()
 664          */
 665         if (remove)
 666                 cmd->se_tfo->aborted_task(cmd);
 667
 668         if (transport_cmd_check_stop_to_fabric(cmd))
 669                 return 1;
 670         if (remove && ack_kref)
 671                 ret = transport_put_cmd(cmd);
 672
 673         return ret;
 674 }
 675
 676 static void target_complete_failure_work(struct work_struct *work)
 677 {
 678         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 679
 680         transport_generic_request_failure(cmd,
 681                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 682 }
 683
 684 /*
 685  * Used when asking transport to copy Sense Data from the underlying
 686  * Linux/SCSI struct scsi_cmnd
 687  */
 688 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 689 {
 690         struct se_device *dev = cmd->se_dev;
 691
 692         WARN_ON(!cmd->se_lun);
 693
 694         if (!dev)
 695                 return NULL;
 696
 697         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 698                 return NULL;
 699
 700         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 701
 702         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 703                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 704         return cmd->sense_buffer;
 705 }
 706
 707 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
 708 {
 709         unsigned char *cmd_sense_buf;
 710         unsigned long flags;
 711
 712         spin_lock_irqsave(&cmd->t_state_lock, flags);
 713         cmd_sense_buf = transport_get_sense_buffer(cmd);
 714         if (!cmd_sense_buf) {
 715                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 716                 return;
 717         }
 718
 719         cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
 720         memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
 721         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 722 }
 723 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
 724
 725 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 726 {
 727         struct se_device *dev = cmd->se_dev;
 728         int success;
 729         unsigned long flags;
 730
 731         cmd->scsi_status = scsi_status;
 732
 733         spin_lock_irqsave(&cmd->t_state_lock, flags);
 734         switch (cmd->scsi_status) {
 735         case SAM_STAT_CHECK_CONDITION:
 736                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 737                         success = 1;
 738                 else
 739                         success = 0;
 740                 break;
 741         default:
 742                 success = 1;
 743                 break;
 744         }
 745
 746         /*
 747          * Check for case where an explicit ABORT_TASK has been received
 748          * and transport_wait_for_tasks() will be waiting for completion..
 749          */
 750         if (cmd->transport_state & CMD_T_ABORTED ||
 751             cmd->transport_state & CMD_T_STOP) {
 752                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 753                 /*
 754                  * If COMPARE_AND_WRITE was stopped by __transport_wait_for_tasks(),
 755                  * release se_device->caw_sem obtained by sbc_compare_and_write()
 756                  * since target_complete_ok_work() or target_complete_failure_work()
 757                  * won't be called to invoke the normal CAW completion callbacks.
 758                  */
 759                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
 760                         up(&dev->caw_sem);
 761                 }
 762                 complete_all(&cmd->t_transport_stop_comp);
 763                 return;
 764         } else if (!success) {
 765                 INIT_WORK(&cmd->work, target_complete_failure_work);
 766         } else {
 767                 INIT_WORK(&cmd->work, target_complete_ok_work);
 768         }
 769
 770         cmd->t_state = TRANSPORT_COMPLETE;
 771         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 772         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 773
 774         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 775                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 776         else
 777                 queue_work(target_completion_wq, &cmd->work);
 778 }
 779 EXPORT_SYMBOL(target_complete_cmd);
 780
 781 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 782 {
 783         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 784                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 785                         cmd->residual_count += cmd->data_length - length;
 786                 } else {
 787                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 788                         cmd->residual_count = cmd->data_length - length;
 789                 }
 790
 791                 cmd->data_length = length;
 792         }
 793
 794         target_complete_cmd(cmd, scsi_status);
 795 }
 796 EXPORT_SYMBOL(target_complete_cmd_with_length);
 797
 798 static void target_add_to_state_list(struct se_cmd *cmd)
 799 {
 800         struct se_device *dev = cmd->se_dev;
 801         unsigned long flags;
 802
 803         spin_lock_irqsave(&dev->execute_task_lock, flags);
 804         if (!cmd->state_active) {
 805                 list_add_tail(&cmd->state_list, &dev->state_list);
 806                 cmd->state_active = true;
 807         }
 808         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 809 }
 810
 811 /*
 812  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 813  */
 814 static void transport_write_pending_qf(struct se_cmd *cmd);
 815 static void transport_complete_qf(struct se_cmd *cmd);
 816
 817 void target_qf_do_work(struct work_struct *work)
 818 {
 819         struct se_device *dev = container_of(work, struct se_device,
 820                                         qf_work_queue);
 821         LIST_HEAD(qf_cmd_list);
 822         struct se_cmd *cmd, *cmd_tmp;
 823
 824         spin_lock_irq(&dev->qf_cmd_lock);
 825         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 826         spin_unlock_irq(&dev->qf_cmd_lock);
 827
 828         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 829                 list_del(&cmd->se_qf_node);
 830                 atomic_dec_mb(&dev->dev_qf_count);
 831
 832                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 833                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 834                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 835                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 836                         : "UNKNOWN");
 837
 838                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 839                         transport_write_pending_qf(cmd);
 840                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 841                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 842                         transport_complete_qf(cmd);
 843         }
 844 }
 845
 846 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 847 {
 848         switch (cmd->data_direction) {
 849         case DMA_NONE:
 850                 return "NONE";
 851         case DMA_FROM_DEVICE:
 852                 return "READ";
 853         case DMA_TO_DEVICE:
 854                 return "WRITE";
 855         case DMA_BIDIRECTIONAL:
 856                 return "BIDI";
 857         default:
 858                 break;
 859         }
 860
 861         return "UNKNOWN";
 862 }
 863
 864 void transport_dump_dev_state(
 865         struct se_device *dev,
 866         char *b,
 867         int *bl)
 868 {
 869         *bl += sprintf(b + *bl, "Status: ");
 870         if (dev->export_count)
 871                 *bl += sprintf(b + *bl, "ACTIVATED");
 872         else
 873                 *bl += sprintf(b + *bl, "DEACTIVATED");
 874
 875         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 876         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 877                 dev->dev_attrib.block_size,
 878                 dev->dev_attrib.hw_max_sectors);
 879         *bl += sprintf(b + *bl, "        ");
 880 }
 881
 882 void transport_dump_vpd_proto_id(
 883         struct t10_vpd *vpd,
 884         unsigned char *p_buf,
 885         int p_buf_len)
 886 {
 887         unsigned char buf[VPD_TMP_BUF_SIZE];
 888         int len;
 889
 890         memset(buf, 0, VPD_TMP_BUF_SIZE);
 891         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 892
 893         switch (vpd->protocol_identifier) {
 894         case 0x00:
 895                 sprintf(buf+len, "Fibre Channel\n");
 896                 break;
 897         case 0x10:
 898                 sprintf(buf+len, "Parallel SCSI\n");
 899                 break;
 900         case 0x20:
 901                 sprintf(buf+len, "SSA\n");
 902                 break;
 903         case 0x30:
 904                 sprintf(buf+len, "IEEE 1394\n");
 905                 break;
 906         case 0x40:
 907                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 908                                 " Protocol\n");
 909                 break;
 910         case 0x50:
 911                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 912                 break;
 913         case 0x60:
 914                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 915                 break;
 916         case 0x70:
 917                 sprintf(buf+len, "Automation/Drive Interface Transport"
 918                                 " Protocol\n");
 919                 break;
 920         case 0x80:
 921                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 922                 break;
 923         default:
 924                 sprintf(buf+len, "Unknown 0x%02x\n",
 925                                 vpd->protocol_identifier);
 926                 break;
 927         }
 928
 929         if (p_buf)
 930                 strncpy(p_buf, buf, p_buf_len);
 931         else
 932                 pr_debug("%s", buf);
 933 }
 934
 935 void
 936 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 937 {
 938         /*
 939          * Check if the Protocol Identifier Valid (PIV) bit is set..
 940          *
 941          * from spc3r23.pdf section 7.5.1
 942          */
 943          if (page_83[1] & 0x80) {
 944                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 945                 vpd->protocol_identifier_set = 1;
 946                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 947         }
 948 }
 949 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 950
 951 int transport_dump_vpd_assoc(
 952         struct t10_vpd *vpd,
 953         unsigned char *p_buf,
 954         int p_buf_len)
 955 {
 956         unsigned char buf[VPD_TMP_BUF_SIZE];
 957         int ret = 0;
 958         int len;
 959
 960         memset(buf, 0, VPD_TMP_BUF_SIZE);
 961         len = sprintf(buf, "T10 VPD Identifier Association: ");
 962
 963         switch (vpd->association) {
 964         case 0x00:
 965                 sprintf(buf+len, "addressed logical unit\n");
 966                 break;
 967         case 0x10:
 968                 sprintf(buf+len, "target port\n");
 969                 break;
 970         case 0x20:
 971                 sprintf(buf+len, "SCSI target device\n");
 972                 break;
 973         default:
 974                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 975                 ret = -EINVAL;
 976                 break;
 977         }
 978
 979         if (p_buf)
 980                 strncpy(p_buf, buf, p_buf_len);
 981         else
 982                 pr_debug("%s", buf);
 983
 984         return ret;
 985 }
 986
 987 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 988 {
 989         /*
 990          * The VPD identification association..
 991          *
 992          * from spc3r23.pdf Section 7.6.3.1 Table 297
 993          */
 994         vpd->association = (page_83[1] & 0x30);
 995         return transport_dump_vpd_assoc(vpd, NULL, 0);
 996 }
 997 EXPORT_SYMBOL(transport_set_vpd_assoc);
 998
 999 int transport_dump_vpd_ident_type(
1000         struct t10_vpd *vpd,
1001         unsigned char *p_buf,
1002         int p_buf_len)
1003 {
1004         unsigned char buf[VPD_TMP_BUF_SIZE];
1005         int ret = 0;
1006         int len;
1007
1008         memset(buf, 0, VPD_TMP_BUF_SIZE);
1009         len = sprintf(buf, "T10 VPD Identifier Type: ");
1010
1011         switch (vpd->device_identifier_type) {
1012         case 0x00:
1013                 sprintf(buf+len, "Vendor specific\n");
1014                 break;
1015         case 0x01:
1016                 sprintf(buf+len, "T10 Vendor ID based\n");
1017                 break;
1018         case 0x02:
1019                 sprintf(buf+len, "EUI-64 based\n");
1020                 break;
1021         case 0x03:
1022                 sprintf(buf+len, "NAA\n");
1023                 break;
1024         case 0x04:
1025                 sprintf(buf+len, "Relative target port identifier\n");
1026                 break;
1027         case 0x08:
1028                 sprintf(buf+len, "SCSI name string\n");
1029                 break;
1030         default:
1031                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1032                                 vpd->device_identifier_type);
1033                 ret = -EINVAL;
1034                 break;
1035         }
1036
1037         if (p_buf) {
1038                 if (p_buf_len < strlen(buf)+1)
1039                         return -EINVAL;
1040                 strncpy(p_buf, buf, p_buf_len);
1041         } else {
1042                 pr_debug("%s", buf);
1043         }
1044
1045         return ret;
1046 }
1047
1048 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1049 {
1050         /*
1051          * The VPD identifier type..
1052          *
1053          * from spc3r23.pdf Section 7.6.3.1 Table 298
1054          */
1055         vpd->device_identifier_type = (page_83[1] & 0x0f);
1056         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1057 }
1058 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1059
1060 int transport_dump_vpd_ident(
1061         struct t10_vpd *vpd,
1062         unsigned char *p_buf,
1063         int p_buf_len)
1064 {
1065         unsigned char buf[VPD_TMP_BUF_SIZE];
1066         int ret = 0;
1067
1068         memset(buf, 0, VPD_TMP_BUF_SIZE);
1069
1070         switch (vpd->device_identifier_code_set) {
1071         case 0x01: /* Binary */
1072                 snprintf(buf, sizeof(buf),
1073                         "T10 VPD Binary Device Identifier: %s\n",
1074                         &vpd->device_identifier[0]);
1075                 break;
1076         case 0x02: /* ASCII */
1077                 snprintf(buf, sizeof(buf),
1078                         "T10 VPD ASCII Device Identifier: %s\n",
1079                         &vpd->device_identifier[0]);
1080                 break;
1081         case 0x03: /* UTF-8 */
1082                 snprintf(buf, sizeof(buf),
1083                         "T10 VPD UTF-8 Device Identifier: %s\n",
1084                         &vpd->device_identifier[0]);
1085                 break;
1086         default:
1087                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1088                         " 0x%02x", vpd->device_identifier_code_set);
1089                 ret = -EINVAL;
1090                 break;
1091         }
1092
1093         if (p_buf)
1094                 strncpy(p_buf, buf, p_buf_len);
1095         else
1096                 pr_debug("%s", buf);
1097
1098         return ret;
1099 }
1100
1101 int
1102 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1103 {
1104         static const char hex_str[] = "0123456789abcdef";
1105         int j = 0, i = 4; /* offset to start of the identifier */
1106
1107         /*
1108          * The VPD Code Set (encoding)
1109          *
1110          * from spc3r23.pdf Section 7.6.3.1 Table 296
1111          */
1112         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1113         switch (vpd->device_identifier_code_set) {
1114         case 0x01: /* Binary */
1115                 vpd->device_identifier[j++] =
1116                                 hex_str[vpd->device_identifier_type];
1117                 while (i < (4 + page_83[3])) {
1118                         vpd->device_identifier[j++] =
1119                                 hex_str[(page_83[i] & 0xf0) >> 4];
1120                         vpd->device_identifier[j++] =
1121                                 hex_str[page_83[i] & 0x0f];
1122                         i++;
1123                 }
1124                 break;
1125         case 0x02: /* ASCII */
1126         case 0x03: /* UTF-8 */
1127                 while (i < (4 + page_83[3]))
1128                         vpd->device_identifier[j++] = page_83[i++];
1129                 break;
1130         default:
1131                 break;
1132         }
1133
1134         return transport_dump_vpd_ident(vpd, NULL, 0);
1135 }
1136 EXPORT_SYMBOL(transport_set_vpd_ident);
1137
1138 static sense_reason_t
1139 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1140                                unsigned int size)
1141 {
1142         u32 mtl;
1143
1144         if (!cmd->se_tfo->max_data_sg_nents)
1145                 return TCM_NO_SENSE;
1146         /*
1147          * Check if fabric enforced maximum SGL entries per I/O descriptor
1148          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1149          * residual_count and reduce original cmd->data_length to maximum
1150          * length based on single PAGE_SIZE entry scatter-lists.
1151          */
1152         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1153         if (cmd->data_length > mtl) {
1154                 /*
1155                  * If an existing CDB overflow is present, calculate new residual
1156                  * based on CDB size minus fabric maximum transfer length.
1157                  *
1158                  * If an existing CDB underflow is present, calculate new residual
1159                  * based on original cmd->data_length minus fabric maximum transfer
1160                  * length.
1161                  *
1162                  * Otherwise, set the underflow residual based on cmd->data_length
1163                  * minus fabric maximum transfer length.
1164                  */
1165                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1166                         cmd->residual_count = (size - mtl);
1167                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1168                         u32 orig_dl = size + cmd->residual_count;
1169                         cmd->residual_count = (orig_dl - mtl);
1170                 } else {
1171                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1172                         cmd->residual_count = (cmd->data_length - mtl);
1173                 }
1174                 cmd->data_length = mtl;
1175                 /*
1176                  * Reset sbc_check_prot() calculated protection payload
1177                  * length based upon the new smaller MTL.
1178                  */
1179                 if (cmd->prot_length) {
1180                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1181                         cmd->prot_length = dev->prot_length * sectors;
1182                 }
1183         }
1184         return TCM_NO_SENSE;
1185 }
1186
1187 sense_reason_t
1188 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1189 {
1190         struct se_device *dev = cmd->se_dev;
1191
1192         if (cmd->unknown_data_length) {
1193                 cmd->data_length = size;
1194         } else if (size != cmd->data_length) {
1195                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1196                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1197                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1198                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1199
1200                 if (cmd->data_direction == DMA_TO_DEVICE) {
1201                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1202                                 pr_err_ratelimited("Rejecting underflow/overflow"
1203                                                    " for WRITE data CDB\n");
1204                                 return TCM_INVALID_CDB_FIELD;
1205                         }
1206                         /*
1207                          * Some fabric drivers like iscsi-target still expect to
1208                          * always reject overflow writes.  Reject this case until
1209                          * full fabric driver level support for overflow writes
1210                          * is introduced tree-wide.
1211                          */
1212                         if (size > cmd->data_length) {
1213                                 pr_err_ratelimited("Rejecting overflow for"
1214                                                    " WRITE control CDB\n");
1215                                 return TCM_INVALID_CDB_FIELD;
1216                         }
1217                 }
1218                 /*
1219                  * Reject READ_* or WRITE_* with overflow/underflow for
1220                  * type SCF_SCSI_DATA_CDB.
1221                  */
1222                 if (dev->dev_attrib.block_size != 512)  {
1223                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1224                                 " CDB on non 512-byte sector setup subsystem"
1225                                 " plugin: %s\n", dev->transport->name);
1226                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1227                         return TCM_INVALID_CDB_FIELD;
1228                 }
1229                 /*
1230                  * For the overflow case keep the existing fabric provided
1231                  * ->data_length.  Otherwise for the underflow case, reset
1232                  * ->data_length to the smaller SCSI expected data transfer
1233                  * length.
1234                  */
1235                 if (size > cmd->data_length) {
1236                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1237                         cmd->residual_count = (size - cmd->data_length);
1238                 } else {
1239                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1240                         cmd->residual_count = (cmd->data_length - size);
1241                         cmd->data_length = size;
1242                 }
1243         }
1244
1245         return target_check_max_data_sg_nents(cmd, dev, size);
1246
1247 }
1248
1249 /*
1250  * Used by fabric modules containing a local struct se_cmd within their
1251  * fabric dependent per I/O descriptor.
1252  *
1253  * Preserves the value of @cmd->tag.
1254  */
1255 void transport_init_se_cmd(
1256         struct se_cmd *cmd,
1257         const struct target_core_fabric_ops *tfo,
1258         struct se_session *se_sess,
1259         u32 data_length,
1260         int data_direction,
1261         int task_attr,
1262         unsigned char *sense_buffer)
1263 {
1264         INIT_LIST_HEAD(&cmd->se_delayed_node);
1265         INIT_LIST_HEAD(&cmd->se_qf_node);
1266         INIT_LIST_HEAD(&cmd->se_cmd_list);
1267         INIT_LIST_HEAD(&cmd->state_list);
1268         init_completion(&cmd->t_transport_stop_comp);
1269         init_completion(&cmd->cmd_wait_comp);
1270         spin_lock_init(&cmd->t_state_lock);
1271         INIT_WORK(&cmd->work, NULL);
1272         kref_init(&cmd->cmd_kref);
1273
1274         cmd->se_tfo = tfo;
1275         cmd->se_sess = se_sess;
1276         cmd->data_length = data_length;
1277         cmd->data_direction = data_direction;
1278         cmd->sam_task_attr = task_attr;
1279         cmd->sense_buffer = sense_buffer;
1280
1281         cmd->state_active = false;
1282 }
1283 EXPORT_SYMBOL(transport_init_se_cmd);
1284
1285 static sense_reason_t
1286 transport_check_alloc_task_attr(struct se_cmd *cmd)
1287 {
1288         struct se_device *dev = cmd->se_dev;
1289
1290         /*
1291          * Check if SAM Task Attribute emulation is enabled for this
1292          * struct se_device storage object
1293          */
1294         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1295                 return 0;
1296
1297         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1298                 pr_debug("SAM Task Attribute ACA"
1299                         " emulation is not supported\n");
1300                 return TCM_INVALID_CDB_FIELD;
1301         }
1302
1303         return 0;
1304 }
1305
1306 sense_reason_t
1307 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1308 {
1309         struct se_device *dev = cmd->se_dev;
1310         sense_reason_t ret;
1311
1312         /*
1313          * Ensure that the received CDB is less than the max (252 + 8) bytes
1314          * for VARIABLE_LENGTH_CMD
1315          */
1316         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1317                 pr_err("Received SCSI CDB with command_size: %d that"
1318                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1319                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1320                 return TCM_INVALID_CDB_FIELD;
1321         }
1322         /*
1323          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1324          * allocate the additional extended CDB buffer now..  Otherwise
1325          * setup the pointer from __t_task_cdb to t_task_cdb.
1326          */
1327         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1328                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1329                                                 GFP_KERNEL);
1330                 if (!cmd->t_task_cdb) {
1331                         pr_err("Unable to allocate cmd->t_task_cdb"
1332                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1333                                 scsi_command_size(cdb),
1334                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1335                         return TCM_OUT_OF_RESOURCES;
1336                 }
1337         } else
1338                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1339         /*
1340          * Copy the original CDB into cmd->
1341          */
1342         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1343
1344         trace_target_sequencer_start(cmd);
1345
1346         ret = dev->transport->parse_cdb(cmd);
1347         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1348                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1349                                     cmd->se_tfo->get_fabric_name(),
1350                                     cmd->se_sess->se_node_acl->initiatorname,
1351                                     cmd->t_task_cdb[0]);
1352         if (ret)
1353                 return ret;
1354
1355         ret = transport_check_alloc_task_attr(cmd);
1356         if (ret)
1357                 return ret;
1358
1359         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1360         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1361         return 0;
1362 }
1363 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1364
1365 /*
1366  * Used by fabric module frontends to queue tasks directly.
1367  * May only be used from process context.
1368  */
1369 int transport_handle_cdb_direct(
1370         struct se_cmd *cmd)
1371 {
1372         sense_reason_t ret;
1373
1374         if (!cmd->se_lun) {
1375                 dump_stack();
1376                 pr_err("cmd->se_lun is NULL\n");
1377                 return -EINVAL;
1378         }
1379         if (in_interrupt()) {
1380                 dump_stack();
1381                 pr_err("transport_generic_handle_cdb cannot be called"
1382                                 " from interrupt context\n");
1383                 return -EINVAL;
1384         }
1385         /*
1386          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1387          * outstanding descriptors are handled correctly during shutdown via
1388          * transport_wait_for_tasks()
1389          *
1390          * Also, we don't take cmd->t_state_lock here as we only expect
1391          * this to be called for initial descriptor submission.
1392          */
1393         cmd->t_state = TRANSPORT_NEW_CMD;
1394         cmd->transport_state |= CMD_T_ACTIVE;
1395
1396         /*
1397          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1398          * so follow TRANSPORT_NEW_CMD processing thread context usage
1399          * and call transport_generic_request_failure() if necessary..
1400          */
1401         ret = transport_generic_new_cmd(cmd);
1402         if (ret)
1403                 transport_generic_request_failure(cmd, ret);
1404         return 0;
1405 }
1406 EXPORT_SYMBOL(transport_handle_cdb_direct);
1407
1408 sense_reason_t
1409 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1410                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1411 {
1412         if (!sgl || !sgl_count)
1413                 return 0;
1414
1415         /*
1416          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1417          * scatterlists already have been set to follow what the fabric
1418          * passes for the original expected data transfer length.
1419          */
1420         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1421                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1422                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1423                 return TCM_INVALID_CDB_FIELD;
1424         }
1425
1426         cmd->t_data_sg = sgl;
1427         cmd->t_data_nents = sgl_count;
1428         cmd->t_bidi_data_sg = sgl_bidi;
1429         cmd->t_bidi_data_nents = sgl_bidi_count;
1430
1431         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1432         return 0;
1433 }
1434
1435 /*
1436  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1437  *                       se_cmd + use pre-allocated SGL memory.
1438  *
1439  * @se_cmd: command descriptor to submit
1440  * @se_sess: associated se_sess for endpoint
1441  * @cdb: pointer to SCSI CDB
1442  * @sense: pointer to SCSI sense buffer
1443  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1444  * @data_length: fabric expected data transfer length
1445  * @task_addr: SAM task attribute
1446  * @data_dir: DMA data direction
1447  * @flags: flags for command submission from target_sc_flags_tables
1448  * @sgl: struct scatterlist memory for unidirectional mapping
1449  * @sgl_count: scatterlist count for unidirectional mapping
1450  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1451  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1452  * @sgl_prot: struct scatterlist memory protection information
1453  * @sgl_prot_count: scatterlist count for protection information
1454  *
1455  * Task tags are supported if the caller has set @se_cmd->tag.
1456  *
1457  * Returns non zero to signal active I/O shutdown failure.  All other
1458  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1459  * but still return zero here.
1460  *
1461  * This may only be called from process context, and also currently
1462  * assumes internal allocation of fabric payload buffer by target-core.
1463  */
1464 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1465                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1466                 u32 data_length, int task_attr, int data_dir, int flags,
1467                 struct scatterlist *sgl, u32 sgl_count,
1468                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1469                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1470 {
1471         struct se_portal_group *se_tpg;
1472         sense_reason_t rc;
1473         int ret;
1474
1475         se_tpg = se_sess->se_tpg;
1476         BUG_ON(!se_tpg);
1477         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1478         BUG_ON(in_interrupt());
1479         /*
1480          * Initialize se_cmd for target operation.  From this point
1481          * exceptions are handled by sending exception status via
1482          * target_core_fabric_ops->queue_status() callback
1483          */
1484         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1485                                 data_length, data_dir, task_attr, sense);
1486
1487         if (flags & TARGET_SCF_USE_CPUID)
1488                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1489         else
1490                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1491
1492         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1493                 se_cmd->unknown_data_length = 1;
1494         /*
1495          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1496          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1497          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1498          * kref_put() to happen during fabric packet acknowledgement.
1499          */
1500         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1501         if (ret)
1502                 return ret;
1503         /*
1504          * Signal bidirectional data payloads to target-core
1505          */
1506         if (flags & TARGET_SCF_BIDI_OP)
1507                 se_cmd->se_cmd_flags |= SCF_BIDI;
1508         /*
1509          * Locate se_lun pointer and attach it to struct se_cmd
1510          */
1511         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1512         if (rc) {
1513                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1514                 target_put_sess_cmd(se_cmd);
1515                 return 0;
1516         }
1517
1518         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1519         if (rc != 0) {
1520                 transport_generic_request_failure(se_cmd, rc);
1521                 return 0;
1522         }
1523
1524         /*
1525          * Save pointers for SGLs containing protection information,
1526          * if present.
1527          */
1528         if (sgl_prot_count) {
1529                 se_cmd->t_prot_sg = sgl_prot;
1530                 se_cmd->t_prot_nents = sgl_prot_count;
1531                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1532         }
1533
1534         /*
1535          * When a non zero sgl_count has been passed perform SGL passthrough
1536          * mapping for pre-allocated fabric memory instead of having target
1537          * core perform an internal SGL allocation..
1538          */
1539         if (sgl_count != 0) {
1540                 BUG_ON(!sgl);
1541
1542                 /*
1543                  * A work-around for tcm_loop as some userspace code via
1544                  * scsi-generic do not memset their associated read buffers,
1545                  * so go ahead and do that here for type non-data CDBs.  Also
1546                  * note that this is currently guaranteed to be a single SGL
1547                  * for this case by target core in target_setup_cmd_from_cdb()
1548                  * -> transport_generic_cmd_sequencer().
1549                  */
1550                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1551                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1552                         unsigned char *buf = NULL;
1553
1554                         if (sgl)
1555                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1556
1557                         if (buf) {
1558                                 memset(buf, 0, sgl->length);
1559                                 kunmap(sg_page(sgl));
1560                         }
1561                 }
1562
1563                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1564                                 sgl_bidi, sgl_bidi_count);
1565                 if (rc != 0) {
1566                         transport_generic_request_failure(se_cmd, rc);
1567                         return 0;
1568                 }
1569         }
1570
1571         /*
1572          * Check if we need to delay processing because of ALUA
1573          * Active/NonOptimized primary access state..
1574          */
1575         core_alua_check_nonop_delay(se_cmd);
1576
1577         transport_handle_cdb_direct(se_cmd);
1578         return 0;
1579 }
1580 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1581
1582 /*
1583  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1584  *
1585  * @se_cmd: command descriptor to submit
1586  * @se_sess: associated se_sess for endpoint
1587  * @cdb: pointer to SCSI CDB
1588  * @sense: pointer to SCSI sense buffer
1589  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1590  * @data_length: fabric expected data transfer length
1591  * @task_addr: SAM task attribute
1592  * @data_dir: DMA data direction
1593  * @flags: flags for command submission from target_sc_flags_tables
1594  *
1595  * Task tags are supported if the caller has set @se_cmd->tag.
1596  *
1597  * Returns non zero to signal active I/O shutdown failure.  All other
1598  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1599  * but still return zero here.
1600  *
1601  * This may only be called from process context, and also currently
1602  * assumes internal allocation of fabric payload buffer by target-core.
1603  *
1604  * It also assumes interal target core SGL memory allocation.
1605  */
1606 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1607                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1608                 u32 data_length, int task_attr, int data_dir, int flags)
1609 {
1610         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1611                         unpacked_lun, data_length, task_attr, data_dir,
1612                         flags, NULL, 0, NULL, 0, NULL, 0);
1613 }
1614 EXPORT_SYMBOL(target_submit_cmd);
1615
1616 static void target_complete_tmr_failure(struct work_struct *work)
1617 {
1618         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1619
1620         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1621         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1622
1623         transport_lun_remove_cmd(se_cmd);
1624         transport_cmd_check_stop_to_fabric(se_cmd);
1625 }
1626
1627 static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
1628                                        u64 *unpacked_lun)
1629 {
1630         struct se_cmd *se_cmd;
1631         unsigned long flags;
1632         bool ret = false;
1633
1634         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
1635         list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
1636                 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1637                         continue;
1638
1639                 if (se_cmd->tag == tag) {
1640                         *unpacked_lun = se_cmd->orig_fe_lun;
1641                         ret = true;
1642                         break;
1643                 }
1644         }
1645         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
1646
1647         return ret;
1648 }
1649
1650 /**
1651  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1652  *                     for TMR CDBs
1653  *
1654  * @se_cmd: command descriptor to submit
1655  * @se_sess: associated se_sess for endpoint
1656  * @sense: pointer to SCSI sense buffer
1657  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1658  * @fabric_context: fabric context for TMR req
1659  * @tm_type: Type of TM request
1660  * @gfp: gfp type for caller
1661  * @tag: referenced task tag for TMR_ABORT_TASK
1662  * @flags: submit cmd flags
1663  *
1664  * Callable from all contexts.
1665  **/
1666
1667 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1668                 unsigned char *sense, u64 unpacked_lun,
1669                 void *fabric_tmr_ptr, unsigned char tm_type,
1670                 gfp_t gfp, u64 tag, int flags)
1671 {
1672         struct se_portal_group *se_tpg;
1673         int ret;
1674
1675         se_tpg = se_sess->se_tpg;
1676         BUG_ON(!se_tpg);
1677
1678         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1679                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1680         /*
1681          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1682          * allocation failure.
1683          */
1684         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1685         if (ret < 0)
1686                 return -ENOMEM;
1687
1688         if (tm_type == TMR_ABORT_TASK)
1689                 se_cmd->se_tmr_req->ref_task_tag = tag;
1690
1691         /* See target_submit_cmd for commentary */
1692         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1693         if (ret) {
1694                 core_tmr_release_req(se_cmd->se_tmr_req);
1695                 return ret;
1696         }
1697         /*
1698          * If this is ABORT_TASK with no explicit fabric provided LUN,
1699          * go ahead and search active session tags for a match to figure
1700          * out unpacked_lun for the original se_cmd.
1701          */
1702         if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
1703                 if (!target_lookup_lun_from_tag(se_sess, tag, &unpacked_lun))
1704                         goto failure;
1705         }
1706
1707         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1708         if (ret)
1709                 goto failure;
1710
1711         transport_generic_handle_tmr(se_cmd);
1712         return 0;
1713
1714         /*
1715          * For callback during failure handling, push this work off
1716          * to process context with TMR_LUN_DOES_NOT_EXIST status.
1717          */
1718 failure:
1719         INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1720         schedule_work(&se_cmd->work);
1721         return 0;
1722 }
1723 EXPORT_SYMBOL(target_submit_tmr);
1724
1725 /*
1726  * Handle SAM-esque emulation for generic transport request failures.
1727  */
1728 void transport_generic_request_failure(struct se_cmd *cmd,
1729                 sense_reason_t sense_reason)
1730 {
1731         int ret = 0, post_ret = 0;
1732
1733         if (transport_check_aborted_status(cmd, 1))
1734                 return;
1735
1736         pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
1737                  sense_reason);
1738         target_show_cmd("-----[ ", cmd);
1739
1740         /*
1741          * For SAM Task Attribute emulation for failed struct se_cmd
1742          */
1743         transport_complete_task_attr(cmd);
1744         /*
1745          * Handle special case for COMPARE_AND_WRITE failure, where the
1746          * callback is expected to drop the per device ->caw_sem.
1747          */
1748         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1749              cmd->transport_complete_callback)
1750                 cmd->transport_complete_callback(cmd, false, &post_ret);
1751
1752         switch (sense_reason) {
1753         case TCM_NON_EXISTENT_LUN:
1754         case TCM_UNSUPPORTED_SCSI_OPCODE:
1755         case TCM_INVALID_CDB_FIELD:
1756         case TCM_INVALID_PARAMETER_LIST:
1757         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1758         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1759         case TCM_UNKNOWN_MODE_PAGE:
1760         case TCM_WRITE_PROTECTED:
1761         case TCM_ADDRESS_OUT_OF_RANGE:
1762         case TCM_CHECK_CONDITION_ABORT_CMD:
1763         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1764         case TCM_CHECK_CONDITION_NOT_READY:
1765         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1766         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1767         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1768         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1769         case TCM_TOO_MANY_TARGET_DESCS:
1770         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1771         case TCM_TOO_MANY_SEGMENT_DESCS:
1772         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1773                 break;
1774         case TCM_OUT_OF_RESOURCES:
1775                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1776                 break;
1777         case TCM_RESERVATION_CONFLICT:
1778                 /*
1779                  * No SENSE Data payload for this case, set SCSI Status
1780                  * and queue the response to $FABRIC_MOD.
1781                  *
1782                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1783                  */
1784                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1785                 /*
1786                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1787                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1788                  * CONFLICT STATUS.
1789                  *
1790                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1791                  */
1792                 if (cmd->se_sess &&
1793                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1794                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1795                                                cmd->orig_fe_lun, 0x2C,
1796                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1797                 }
1798                 trace_target_cmd_complete(cmd);
1799                 ret = cmd->se_tfo->queue_status(cmd);
1800                 if (ret)
1801                         goto queue_full;
1802                 goto check_stop;
1803         default:
1804                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1805                         cmd->t_task_cdb[0], sense_reason);
1806                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1807                 break;
1808         }
1809
1810         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1811         if (ret)
1812                 goto queue_full;
1813
1814 check_stop:
1815         transport_lun_remove_cmd(cmd);
1816         transport_cmd_check_stop_to_fabric(cmd);
1817         return;
1818
1819 queue_full:
1820         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1821 }
1822 EXPORT_SYMBOL(transport_generic_request_failure);
1823
1824 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1825 {
1826         sense_reason_t ret;
1827
1828         if (!cmd->execute_cmd) {
1829                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1830                 goto err;
1831         }
1832         if (do_checks) {
1833                 /*
1834                  * Check for an existing UNIT ATTENTION condition after
1835                  * target_handle_task_attr() has done SAM task attr
1836                  * checking, and possibly have already defered execution
1837                  * out to target_restart_delayed_cmds() context.
1838                  */
1839                 ret = target_scsi3_ua_check(cmd);
1840                 if (ret)
1841                         goto err;
1842
1843                 ret = target_alua_state_check(cmd);
1844                 if (ret)
1845                         goto err;
1846
1847                 ret = target_check_reservation(cmd);
1848                 if (ret) {
1849                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1850                         goto err;
1851                 }
1852         }
1853
1854         ret = cmd->execute_cmd(cmd);
1855         if (!ret)
1856                 return;
1857 err:
1858         spin_lock_irq(&cmd->t_state_lock);
1859         cmd->transport_state &= ~CMD_T_SENT;
1860         spin_unlock_irq(&cmd->t_state_lock);
1861
1862         transport_generic_request_failure(cmd, ret);
1863 }
1864
1865 static int target_write_prot_action(struct se_cmd *cmd)
1866 {
1867         u32 sectors;
1868         /*
1869          * Perform WRITE_INSERT of PI using software emulation when backend
1870          * device has PI enabled, if the transport has not already generated
1871          * PI using hardware WRITE_INSERT offload.
1872          */
1873         switch (cmd->prot_op) {
1874         case TARGET_PROT_DOUT_INSERT:
1875                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1876                         sbc_dif_generate(cmd);
1877                 break;
1878         case TARGET_PROT_DOUT_STRIP:
1879                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1880                         break;
1881
1882                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1883                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1884                                              sectors, 0, cmd->t_prot_sg, 0);
1885                 if (unlikely(cmd->pi_err)) {
1886                         spin_lock_irq(&cmd->t_state_lock);
1887                         cmd->transport_state &= ~CMD_T_SENT;
1888                         spin_unlock_irq(&cmd->t_state_lock);
1889                         transport_generic_request_failure(cmd, cmd->pi_err);
1890                         return -1;
1891                 }
1892                 break;
1893         default:
1894                 break;
1895         }
1896
1897         return 0;
1898 }
1899
1900 static bool target_handle_task_attr(struct se_cmd *cmd)
1901 {
1902         struct se_device *dev = cmd->se_dev;
1903
1904         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1905                 return false;
1906
1907         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1908
1909         /*
1910          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1911          * to allow the passed struct se_cmd list of tasks to the front of the list.
1912          */
1913         switch (cmd->sam_task_attr) {
1914         case TCM_HEAD_TAG:
1915                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1916                          cmd->t_task_cdb[0]);
1917                 return false;
1918         case TCM_ORDERED_TAG:
1919                 atomic_inc_mb(&dev->dev_ordered_sync);
1920
1921                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1922                          cmd->t_task_cdb[0]);
1923
1924                 /*
1925                  * Execute an ORDERED command if no other older commands
1926                  * exist that need to be completed first.
1927                  */
1928                 if (!atomic_read(&dev->simple_cmds))
1929                         return false;
1930                 break;
1931         default:
1932                 /*
1933                  * For SIMPLE and UNTAGGED Task Attribute commands
1934                  */
1935                 atomic_inc_mb(&dev->simple_cmds);
1936                 break;
1937         }
1938
1939         if (atomic_read(&dev->dev_ordered_sync) == 0)
1940                 return false;
1941
1942         spin_lock(&dev->delayed_cmd_lock);
1943         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1944         spin_unlock(&dev->delayed_cmd_lock);
1945
1946         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1947                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1948         return true;
1949 }
1950
1951 static int __transport_check_aborted_status(struct se_cmd *, int);
1952
1953 void target_execute_cmd(struct se_cmd *cmd)
1954 {
1955         /*
1956          * Determine if frontend context caller is requesting the stopping of
1957          * this command for frontend exceptions.
1958          *
1959          * If the received CDB has aleady been aborted stop processing it here.
1960          */
1961         spin_lock_irq(&cmd->t_state_lock);
1962         if (__transport_check_aborted_status(cmd, 1)) {
1963                 spin_unlock_irq(&cmd->t_state_lock);
1964                 return;
1965         }
1966         if (cmd->transport_state & CMD_T_STOP) {
1967                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1968                         __func__, __LINE__, cmd->tag);
1969
1970                 spin_unlock_irq(&cmd->t_state_lock);
1971                 complete_all(&cmd->t_transport_stop_comp);
1972                 return;
1973         }
1974
1975         cmd->t_state = TRANSPORT_PROCESSING;
1976         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
1977         spin_unlock_irq(&cmd->t_state_lock);
1978
1979         if (target_write_prot_action(cmd))
1980                 return;
1981
1982         if (target_handle_task_attr(cmd)) {
1983                 spin_lock_irq(&cmd->t_state_lock);
1984                 cmd->transport_state &= ~CMD_T_SENT;
1985                 spin_unlock_irq(&cmd->t_state_lock);
1986                 return;
1987         }
1988
1989         __target_execute_cmd(cmd, true);
1990 }
1991 EXPORT_SYMBOL(target_execute_cmd);
1992
1993 /*
1994  * Process all commands up to the last received ORDERED task attribute which
1995  * requires another blocking boundary
1996  */
1997 static void target_restart_delayed_cmds(struct se_device *dev)
1998 {
1999         for (;;) {
2000                 struct se_cmd *cmd;
2001
2002                 spin_lock(&dev->delayed_cmd_lock);
2003                 if (list_empty(&dev->delayed_cmd_list)) {
2004                         spin_unlock(&dev->delayed_cmd_lock);
2005                         break;
2006                 }
2007
2008                 cmd = list_entry(dev->delayed_cmd_list.next,
2009                                  struct se_cmd, se_delayed_node);
2010                 list_del(&cmd->se_delayed_node);
2011                 spin_unlock(&dev->delayed_cmd_lock);
2012
2013                 __target_execute_cmd(cmd, true);
2014
2015                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
2016                         break;
2017         }
2018 }
2019
2020 /*
2021  * Called from I/O completion to determine which dormant/delayed
2022  * and ordered cmds need to have their tasks added to the execution queue.
2023  */
2024 static void transport_complete_task_attr(struct se_cmd *cmd)
2025 {
2026         struct se_device *dev = cmd->se_dev;
2027
2028         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2029                 return;
2030
2031         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2032                 goto restart;
2033
2034         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2035                 atomic_dec_mb(&dev->simple_cmds);
2036                 dev->dev_cur_ordered_id++;
2037         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2038                 dev->dev_cur_ordered_id++;
2039                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2040                          dev->dev_cur_ordered_id);
2041         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2042                 atomic_dec_mb(&dev->dev_ordered_sync);
2043
2044                 dev->dev_cur_ordered_id++;
2045                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2046                          dev->dev_cur_ordered_id);
2047         }
2048 restart:
2049         target_restart_delayed_cmds(dev);
2050 }
2051
2052 static void transport_complete_qf(struct se_cmd *cmd)
2053 {
2054         int ret = 0;
2055
2056         transport_complete_task_attr(cmd);
2057         /*
2058          * If a fabric driver ->write_pending() or ->queue_data_in() callback
2059          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2060          * the same callbacks should not be retried.  Return CHECK_CONDITION
2061          * if a scsi_status is not already set.
2062          *
2063          * If a fabric driver ->queue_status() has returned non zero, always
2064          * keep retrying no matter what..
2065          */
2066         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2067                 if (cmd->scsi_status)
2068                         goto queue_status;
2069
2070                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2071                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2072                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2073                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2074                 goto queue_status;
2075         }
2076
2077         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2078                 goto queue_status;
2079
2080         switch (cmd->data_direction) {
2081         case DMA_FROM_DEVICE:
2082                 if (cmd->scsi_status)
2083                         goto queue_status;
2084
2085                 trace_target_cmd_complete(cmd);
2086                 ret = cmd->se_tfo->queue_data_in(cmd);
2087                 break;
2088         case DMA_TO_DEVICE:
2089                 if (cmd->se_cmd_flags & SCF_BIDI) {
2090                         ret = cmd->se_tfo->queue_data_in(cmd);
2091                         break;
2092                 }
2093                 /* Fall through for DMA_TO_DEVICE */
2094         case DMA_NONE:
2095 queue_status:
2096                 trace_target_cmd_complete(cmd);
2097                 ret = cmd->se_tfo->queue_status(cmd);
2098                 break;
2099         default:
2100                 break;
2101         }
2102
2103         if (ret < 0) {
2104                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2105                 return;
2106         }
2107         transport_lun_remove_cmd(cmd);
2108         transport_cmd_check_stop_to_fabric(cmd);
2109 }
2110
2111 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2112                                         int err, bool write_pending)
2113 {
2114         /*
2115          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2116          * ->queue_data_in() callbacks from new process context.
2117          *
2118          * Otherwise for other errors, transport_complete_qf() will send
2119          * CHECK_CONDITION via ->queue_status() instead of attempting to
2120          * retry associated fabric driver data-transfer callbacks.
2121          */
2122         if (err == -EAGAIN || err == -ENOMEM) {
2123                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2124                                                  TRANSPORT_COMPLETE_QF_OK;
2125         } else {
2126                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2127                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2128         }
2129
2130         spin_lock_irq(&dev->qf_cmd_lock);
2131         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2132         atomic_inc_mb(&dev->dev_qf_count);
2133         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2134
2135         schedule_work(&cmd->se_dev->qf_work_queue);
2136 }
2137
2138 static bool target_read_prot_action(struct se_cmd *cmd)
2139 {
2140         switch (cmd->prot_op) {
2141         case TARGET_PROT_DIN_STRIP:
2142                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2143                         u32 sectors = cmd->data_length >>
2144                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2145
2146                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2147                                                      sectors, 0, cmd->t_prot_sg,
2148                                                      0);
2149                         if (cmd->pi_err)
2150                                 return true;
2151                 }
2152                 break;
2153         case TARGET_PROT_DIN_INSERT:
2154                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2155                         break;
2156
2157                 sbc_dif_generate(cmd);
2158                 break;
2159         default:
2160                 break;
2161         }
2162
2163         return false;
2164 }
2165
2166 static void target_complete_ok_work(struct work_struct *work)
2167 {
2168         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2169         int ret;
2170
2171         /*
2172          * Check if we need to move delayed/dormant tasks from cmds on the
2173          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2174          * Attribute.
2175          */
2176         transport_complete_task_attr(cmd);
2177
2178         /*
2179          * Check to schedule QUEUE_FULL work, or execute an existing
2180          * cmd->transport_qf_callback()
2181          */
2182         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2183                 schedule_work(&cmd->se_dev->qf_work_queue);
2184
2185         /*
2186          * Check if we need to send a sense buffer from
2187          * the struct se_cmd in question.
2188          */
2189         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2190                 WARN_ON(!cmd->scsi_status);
2191                 ret = transport_send_check_condition_and_sense(
2192                                         cmd, 0, 1);
2193                 if (ret)
2194                         goto queue_full;
2195
2196                 transport_lun_remove_cmd(cmd);
2197                 transport_cmd_check_stop_to_fabric(cmd);
2198                 return;
2199         }
2200         /*
2201          * Check for a callback, used by amongst other things
2202          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2203          */
2204         if (cmd->transport_complete_callback) {
2205                 sense_reason_t rc;
2206                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2207                 bool zero_dl = !(cmd->data_length);
2208                 int post_ret = 0;
2209
2210                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2211                 if (!rc && !post_ret) {
2212                         if (caw && zero_dl)
2213                                 goto queue_rsp;
2214
2215                         return;
2216                 } else if (rc) {
2217                         ret = transport_send_check_condition_and_sense(cmd,
2218                                                 rc, 0);
2219                         if (ret)
2220                                 goto queue_full;
2221
2222                         transport_lun_remove_cmd(cmd);
2223                         transport_cmd_check_stop_to_fabric(cmd);
2224                         return;
2225                 }
2226         }
2227
2228 queue_rsp:
2229         switch (cmd->data_direction) {
2230         case DMA_FROM_DEVICE:
2231                 if (cmd->scsi_status)
2232                         goto queue_status;
2233
2234                 atomic_long_add(cmd->data_length,
2235                                 &cmd->se_lun->lun_stats.tx_data_octets);
2236                 /*
2237                  * Perform READ_STRIP of PI using software emulation when
2238                  * backend had PI enabled, if the transport will not be
2239                  * performing hardware READ_STRIP offload.
2240                  */
2241                 if (target_read_prot_action(cmd)) {
2242                         ret = transport_send_check_condition_and_sense(cmd,
2243                                                 cmd->pi_err, 0);
2244                         if (ret)
2245                                 goto queue_full;
2246
2247                         transport_lun_remove_cmd(cmd);
2248                         transport_cmd_check_stop_to_fabric(cmd);
2249                         return;
2250                 }
2251
2252                 trace_target_cmd_complete(cmd);
2253                 ret = cmd->se_tfo->queue_data_in(cmd);
2254                 if (ret)
2255                         goto queue_full;
2256                 break;
2257         case DMA_TO_DEVICE:
2258                 atomic_long_add(cmd->data_length,
2259                                 &cmd->se_lun->lun_stats.rx_data_octets);
2260                 /*
2261                  * Check if we need to send READ payload for BIDI-COMMAND
2262                  */
2263                 if (cmd->se_cmd_flags & SCF_BIDI) {
2264                         atomic_long_add(cmd->data_length,
2265                                         &cmd->se_lun->lun_stats.tx_data_octets);
2266                         ret = cmd->se_tfo->queue_data_in(cmd);
2267                         if (ret)
2268                                 goto queue_full;
2269                         break;
2270                 }
2271                 /* Fall through for DMA_TO_DEVICE */
2272         case DMA_NONE:
2273 queue_status:
2274                 trace_target_cmd_complete(cmd);
2275                 ret = cmd->se_tfo->queue_status(cmd);
2276                 if (ret)
2277                         goto queue_full;
2278                 break;
2279         default:
2280                 break;
2281         }
2282
2283         transport_lun_remove_cmd(cmd);
2284         transport_cmd_check_stop_to_fabric(cmd);
2285         return;
2286
2287 queue_full:
2288         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2289                 " data_direction: %d\n", cmd, cmd->data_direction);
2290
2291         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2292 }
2293
2294 void target_free_sgl(struct scatterlist *sgl, int nents)
2295 {
2296         struct scatterlist *sg;
2297         int count;
2298
2299         for_each_sg(sgl, sg, nents, count)
2300                 __free_page(sg_page(sg));
2301
2302         kfree(sgl);
2303 }
2304 EXPORT_SYMBOL(target_free_sgl);
2305
2306 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2307 {
2308         /*
2309          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2310          * emulation, and free + reset pointers if necessary..
2311          */
2312         if (!cmd->t_data_sg_orig)
2313                 return;
2314
2315         kfree(cmd->t_data_sg);
2316         cmd->t_data_sg = cmd->t_data_sg_orig;
2317         cmd->t_data_sg_orig = NULL;
2318         cmd->t_data_nents = cmd->t_data_nents_orig;
2319         cmd->t_data_nents_orig = 0;
2320 }
2321
2322 static inline void transport_free_pages(struct se_cmd *cmd)
2323 {
2324         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2325                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2326                 cmd->t_prot_sg = NULL;
2327                 cmd->t_prot_nents = 0;
2328         }
2329
2330         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2331                 /*
2332                  * Release special case READ buffer payload required for
2333                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2334                  */
2335                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2336                         target_free_sgl(cmd->t_bidi_data_sg,
2337                                            cmd->t_bidi_data_nents);
2338                         cmd->t_bidi_data_sg = NULL;
2339                         cmd->t_bidi_data_nents = 0;
2340                 }
2341                 transport_reset_sgl_orig(cmd);
2342                 return;
2343         }
2344         transport_reset_sgl_orig(cmd);
2345
2346         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2347         cmd->t_data_sg = NULL;
2348         cmd->t_data_nents = 0;
2349
2350         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2351         cmd->t_bidi_data_sg = NULL;
2352         cmd->t_bidi_data_nents = 0;
2353 }
2354
2355 /**
2356  * transport_put_cmd - release a reference to a command
2357  * @cmd:       command to release
2358  *
2359  * This routine releases our reference to the command and frees it if possible.
2360  */
2361 static int transport_put_cmd(struct se_cmd *cmd)
2362 {
2363         BUG_ON(!cmd->se_tfo);
2364         /*
2365          * If this cmd has been setup with target_get_sess_cmd(), drop
2366          * the kref and call ->release_cmd() in kref callback.
2367          */
2368         return target_put_sess_cmd(cmd);
2369 }
2370
2371 void *transport_kmap_data_sg(struct se_cmd *cmd)
2372 {
2373         struct scatterlist *sg = cmd->t_data_sg;
2374         struct page **pages;
2375         int i;
2376
2377         /*
2378          * We need to take into account a possible offset here for fabrics like
2379          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2380          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2381          */
2382         if (!cmd->t_data_nents)
2383                 return NULL;
2384
2385         BUG_ON(!sg);
2386         if (cmd->t_data_nents == 1)
2387                 return kmap(sg_page(sg)) + sg->offset;
2388
2389         /* >1 page. use vmap */
2390         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2391         if (!pages)
2392                 return NULL;
2393
2394         /* convert sg[] to pages[] */
2395         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2396                 pages[i] = sg_page(sg);
2397         }
2398
2399         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2400         kfree(pages);
2401         if (!cmd->t_data_vmap)
2402                 return NULL;
2403
2404         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2405 }
2406 EXPORT_SYMBOL(transport_kmap_data_sg);
2407
2408 void transport_kunmap_data_sg(struct se_cmd *cmd)
2409 {
2410         if (!cmd->t_data_nents) {
2411                 return;
2412         } else if (cmd->t_data_nents == 1) {
2413                 kunmap(sg_page(cmd->t_data_sg));
2414                 return;
2415         }
2416
2417         vunmap(cmd->t_data_vmap);
2418         cmd->t_data_vmap = NULL;
2419 }
2420 EXPORT_SYMBOL(transport_kunmap_data_sg);
2421
2422 int
2423 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2424                  bool zero_page, bool chainable)
2425 {
2426         struct scatterlist *sg;
2427         struct page *page;
2428         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2429         unsigned int nalloc, nent;
2430         int i = 0;
2431
2432         nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2433         if (chainable)
2434                 nalloc++;
2435         sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2436         if (!sg)
2437                 return -ENOMEM;
2438
2439         sg_init_table(sg, nalloc);
2440
2441         while (length) {
2442                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2443                 page = alloc_page(GFP_KERNEL | zero_flag);
2444                 if (!page)
2445                         goto out;
2446
2447                 sg_set_page(&sg[i], page, page_len, 0);
2448                 length -= page_len;
2449                 i++;
2450         }
2451         *sgl = sg;
2452         *nents = nent;
2453         return 0;
2454
2455 out:
2456         while (i > 0) {
2457                 i--;
2458                 __free_page(sg_page(&sg[i]));
2459         }
2460         kfree(sg);
2461         return -ENOMEM;
2462 }
2463 EXPORT_SYMBOL(target_alloc_sgl);
2464
2465 /*
2466  * Allocate any required resources to execute the command.  For writes we
2467  * might not have the payload yet, so notify the fabric via a call to
2468  * ->write_pending instead. Otherwise place it on the execution queue.
2469  */
2470 sense_reason_t
2471 transport_generic_new_cmd(struct se_cmd *cmd)
2472 {
2473         unsigned long flags;
2474         int ret = 0;
2475         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2476
2477         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2478             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2479                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2480                                        cmd->prot_length, true, false);
2481                 if (ret < 0)
2482                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2483         }
2484
2485         /*
2486          * Determine is the TCM fabric module has already allocated physical
2487          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2488          * beforehand.
2489          */
2490         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2491             cmd->data_length) {
2492
2493                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2494                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2495                         u32 bidi_length;
2496
2497                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2498                                 bidi_length = cmd->t_task_nolb *
2499                                               cmd->se_dev->dev_attrib.block_size;
2500                         else
2501                                 bidi_length = cmd->data_length;
2502
2503                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2504                                                &cmd->t_bidi_data_nents,
2505                                                bidi_length, zero_flag, false);
2506                         if (ret < 0)
2507                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2508                 }
2509
2510                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2511                                        cmd->data_length, zero_flag, false);
2512                 if (ret < 0)
2513                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2514         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2515                     cmd->data_length) {
2516                 /*
2517                  * Special case for COMPARE_AND_WRITE with fabrics
2518                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2519                  */
2520                 u32 caw_length = cmd->t_task_nolb *
2521                                  cmd->se_dev->dev_attrib.block_size;
2522
2523                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2524                                        &cmd->t_bidi_data_nents,
2525                                        caw_length, zero_flag, false);
2526                 if (ret < 0)
2527                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2528         }
2529         /*
2530          * If this command is not a write we can execute it right here,
2531          * for write buffers we need to notify the fabric driver first
2532          * and let it call back once the write buffers are ready.
2533          */
2534         target_add_to_state_list(cmd);
2535         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2536                 target_execute_cmd(cmd);
2537                 return 0;
2538         }
2539
2540         spin_lock_irqsave(&cmd->t_state_lock, flags);
2541         cmd->t_state = TRANSPORT_WRITE_PENDING;
2542         /*
2543          * Determine if frontend context caller is requesting the stopping of
2544          * this command for frontend exceptions.
2545          */
2546         if (cmd->transport_state & CMD_T_STOP) {
2547                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2548                          __func__, __LINE__, cmd->tag);
2549
2550                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2551
2552                 complete_all(&cmd->t_transport_stop_comp);
2553                 return 0;
2554         }
2555         cmd->transport_state &= ~CMD_T_ACTIVE;
2556         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2557
2558         ret = cmd->se_tfo->write_pending(cmd);
2559         if (ret)
2560                 goto queue_full;
2561
2562         return 0;
2563
2564 queue_full:
2565         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2566         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2567         return 0;
2568 }
2569 EXPORT_SYMBOL(transport_generic_new_cmd);
2570
2571 static void transport_write_pending_qf(struct se_cmd *cmd)
2572 {
2573         int ret;
2574
2575         ret = cmd->se_tfo->write_pending(cmd);
2576         if (ret) {
2577                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2578                          cmd);
2579                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2580         }
2581 }
2582
2583 static bool
2584 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2585                            unsigned long *flags);
2586
2587 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2588 {
2589         unsigned long flags;
2590
2591         spin_lock_irqsave(&cmd->t_state_lock, flags);
2592         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2593         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2594 }
2595
2596 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2597 {
2598         int ret = 0;
2599         bool aborted = false, tas = false;
2600
2601         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2602                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2603                         target_wait_free_cmd(cmd, &aborted, &tas);
2604
2605                 if (!aborted || tas)
2606                         ret = transport_put_cmd(cmd);
2607         } else {
2608                 if (wait_for_tasks)
2609                         target_wait_free_cmd(cmd, &aborted, &tas);
2610                 /*
2611                  * Handle WRITE failure case where transport_generic_new_cmd()
2612                  * has already added se_cmd to state_list, but fabric has
2613                  * failed command before I/O submission.
2614                  */
2615                 if (cmd->state_active)
2616                         target_remove_from_state_list(cmd);
2617
2618                 if (cmd->se_lun)
2619                         transport_lun_remove_cmd(cmd);
2620
2621                 if (!aborted || tas)
2622                         ret = transport_put_cmd(cmd);
2623         }
2624         /*
2625          * If the task has been internally aborted due to TMR ABORT_TASK
2626          * or LUN_RESET, target_core_tmr.c is responsible for performing
2627          * the remaining calls to target_put_sess_cmd(), and not the
2628          * callers of this function.
2629          */
2630         if (aborted) {
2631                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2632                 wait_for_completion(&cmd->cmd_wait_comp);
2633                 cmd->se_tfo->release_cmd(cmd);
2634                 ret = 1;
2635         }
2636         return ret;
2637 }
2638 EXPORT_SYMBOL(transport_generic_free_cmd);
2639
2640 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2641  * @se_cmd:     command descriptor to add
2642  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2643  */
2644 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2645 {
2646         struct se_session *se_sess = se_cmd->se_sess;
2647         unsigned long flags;
2648         int ret = 0;
2649
2650         /*
2651          * Add a second kref if the fabric caller is expecting to handle
2652          * fabric acknowledgement that requires two target_put_sess_cmd()
2653          * invocations before se_cmd descriptor release.
2654          */
2655         if (ack_kref) {
2656                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2657                         return -EINVAL;
2658
2659                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2660         }
2661
2662         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2663         if (se_sess->sess_tearing_down) {
2664                 ret = -ESHUTDOWN;
2665                 goto out;
2666         }
2667         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2668 out:
2669         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2670
2671         if (ret && ack_kref)
2672                 target_put_sess_cmd(se_cmd);
2673
2674         return ret;
2675 }
2676 EXPORT_SYMBOL(target_get_sess_cmd);
2677
2678 static void target_free_cmd_mem(struct se_cmd *cmd)
2679 {
2680         transport_free_pages(cmd);
2681
2682         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2683                 core_tmr_release_req(cmd->se_tmr_req);
2684         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2685                 kfree(cmd->t_task_cdb);
2686 }
2687
2688 static void target_release_cmd_kref(struct kref *kref)
2689 {
2690         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2691         struct se_session *se_sess = se_cmd->se_sess;
2692         unsigned long flags;
2693         bool fabric_stop;
2694
2695         if (se_sess) {
2696                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2697
2698                 spin_lock(&se_cmd->t_state_lock);
2699                 fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2700                               (se_cmd->transport_state & CMD_T_ABORTED);
2701                 spin_unlock(&se_cmd->t_state_lock);
2702
2703                 if (se_cmd->cmd_wait_set || fabric_stop) {
2704                         list_del_init(&se_cmd->se_cmd_list);
2705                         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2706                         target_free_cmd_mem(se_cmd);
2707                         complete(&se_cmd->cmd_wait_comp);
2708                         return;
2709                 }
2710                 list_del_init(&se_cmd->se_cmd_list);
2711                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2712         }
2713
2714         target_free_cmd_mem(se_cmd);
2715         se_cmd->se_tfo->release_cmd(se_cmd);
2716 }
2717
2718 /**
2719  * target_put_sess_cmd - decrease the command reference count
2720  * @se_cmd:     command to drop a reference from
2721  *
2722  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2723  * refcount to drop to zero. Returns zero otherwise.
2724  */
2725 int target_put_sess_cmd(struct se_cmd *se_cmd)
2726 {
2727         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2728 }
2729 EXPORT_SYMBOL(target_put_sess_cmd);
2730
2731 static const char *data_dir_name(enum dma_data_direction d)
2732 {
2733         switch (d) {
2734         case DMA_BIDIRECTIONAL: return "BIDI";
2735         case DMA_TO_DEVICE:     return "WRITE";
2736         case DMA_FROM_DEVICE:   return "READ";
2737         case DMA_NONE:          return "NONE";
2738         }
2739
2740         return "(?)";
2741 }
2742
2743 static const char *cmd_state_name(enum transport_state_table t)
2744 {
2745         switch (t) {
2746         case TRANSPORT_NO_STATE:        return "NO_STATE";
2747         case TRANSPORT_NEW_CMD:         return "NEW_CMD";
2748         case TRANSPORT_WRITE_PENDING:   return "WRITE_PENDING";
2749         case TRANSPORT_PROCESSING:      return "PROCESSING";
2750         case TRANSPORT_COMPLETE:        return "COMPLETE";
2751         case TRANSPORT_ISTATE_PROCESSING:
2752                                         return "ISTATE_PROCESSING";
2753         case TRANSPORT_COMPLETE_QF_WP:  return "COMPLETE_QF_WP";
2754         case TRANSPORT_COMPLETE_QF_OK:  return "COMPLETE_QF_OK";
2755         case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
2756         }
2757
2758         return "(?)";
2759 }
2760
2761 static void target_append_str(char **str, const char *txt)
2762 {
2763         char *prev = *str;
2764
2765         *str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
2766                 kstrdup(txt, GFP_ATOMIC);
2767         kfree(prev);
2768 }
2769
2770 /*
2771  * Convert a transport state bitmask into a string. The caller is
2772  * responsible for freeing the returned pointer.
2773  */
2774 static char *target_ts_to_str(u32 ts)
2775 {
2776         char *str = NULL;
2777
2778         if (ts & CMD_T_ABORTED)
2779                 target_append_str(&str, "aborted");
2780         if (ts & CMD_T_ACTIVE)
2781                 target_append_str(&str, "active");
2782         if (ts & CMD_T_COMPLETE)
2783                 target_append_str(&str, "complete");
2784         if (ts & CMD_T_SENT)
2785                 target_append_str(&str, "sent");
2786         if (ts & CMD_T_STOP)
2787                 target_append_str(&str, "stop");
2788         if (ts & CMD_T_FABRIC_STOP)
2789                 target_append_str(&str, "fabric_stop");
2790
2791         return str;
2792 }
2793
2794 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
2795 {
2796         switch (tmf) {
2797         case TMR_ABORT_TASK:            return "ABORT_TASK";
2798         case TMR_ABORT_TASK_SET:        return "ABORT_TASK_SET";
2799         case TMR_CLEAR_ACA:             return "CLEAR_ACA";
2800         case TMR_CLEAR_TASK_SET:        return "CLEAR_TASK_SET";
2801         case TMR_LUN_RESET:             return "LUN_RESET";
2802         case TMR_TARGET_WARM_RESET:     return "TARGET_WARM_RESET";
2803         case TMR_TARGET_COLD_RESET:     return "TARGET_COLD_RESET";
2804         case TMR_UNKNOWN:               break;
2805         }
2806         return "(?)";
2807 }
2808
2809 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
2810 {
2811         char *ts_str = target_ts_to_str(cmd->transport_state);
2812         const u8 *cdb = cmd->t_task_cdb;
2813         struct se_tmr_req *tmf = cmd->se_tmr_req;
2814
2815         if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2816                 pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
2817                          pfx, cdb[0], cdb[1], cmd->tag,
2818                          data_dir_name(cmd->data_direction),
2819                          cmd->se_tfo->get_cmd_state(cmd),
2820                          cmd_state_name(cmd->t_state), cmd->data_length,
2821                          kref_read(&cmd->cmd_kref), ts_str);
2822         } else {
2823                 pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
2824                          pfx, target_tmf_name(tmf->function), cmd->tag,
2825                          tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
2826                          cmd_state_name(cmd->t_state),
2827                          kref_read(&cmd->cmd_kref), ts_str);
2828         }
2829         kfree(ts_str);
2830 }
2831 EXPORT_SYMBOL(target_show_cmd);
2832
2833 /* target_sess_cmd_list_set_waiting - Flag all commands in
2834  *         sess_cmd_list to complete cmd_wait_comp.  Set
2835  *         sess_tearing_down so no more commands are queued.
2836  * @se_sess:    session to flag
2837  */
2838 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2839 {
2840         struct se_cmd *se_cmd, *tmp_cmd;
2841         unsigned long flags;
2842         int rc;
2843
2844         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2845         if (se_sess->sess_tearing_down) {
2846                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2847                 return;
2848         }
2849         se_sess->sess_tearing_down = 1;
2850         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2851
2852         list_for_each_entry_safe(se_cmd, tmp_cmd,
2853                                  &se_sess->sess_wait_list, se_cmd_list) {
2854                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2855                 if (rc) {
2856                         se_cmd->cmd_wait_set = 1;
2857                         spin_lock(&se_cmd->t_state_lock);
2858                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2859                         spin_unlock(&se_cmd->t_state_lock);
2860                 } else
2861                         list_del_init(&se_cmd->se_cmd_list);
2862         }
2863
2864         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2865 }
2866 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2867
2868 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2869  * @se_sess:    session to wait for active I/O
2870  */
2871 void target_wait_for_sess_cmds(struct se_session *se_sess)
2872 {
2873         struct se_cmd *se_cmd, *tmp_cmd;
2874         unsigned long flags;
2875         bool tas;
2876
2877         list_for_each_entry_safe(se_cmd, tmp_cmd,
2878                                 &se_sess->sess_wait_list, se_cmd_list) {
2879                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2880                         " %d\n", se_cmd, se_cmd->t_state,
2881                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2882
2883                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2884                 tas = (se_cmd->transport_state & CMD_T_TAS);
2885                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2886
2887                 if (!target_put_sess_cmd(se_cmd)) {
2888                         if (tas)
2889                                 target_put_sess_cmd(se_cmd);
2890                 }
2891
2892                 wait_for_completion(&se_cmd->cmd_wait_comp);
2893                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2894                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2895                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2896
2897                 se_cmd->se_tfo->release_cmd(se_cmd);
2898         }
2899
2900         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2901         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2902         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2903
2904 }
2905 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2906
2907 static void target_lun_confirm(struct percpu_ref *ref)
2908 {
2909         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2910
2911         complete(&lun->lun_ref_comp);
2912 }
2913
2914 void transport_clear_lun_ref(struct se_lun *lun)
2915 {
2916         /*
2917          * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2918          * the initial reference and schedule confirm kill to be
2919          * executed after one full RCU grace period has completed.
2920          */
2921         percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2922         /*
2923          * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2924          * to call target_lun_confirm after lun->lun_ref has been marked
2925          * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2926          * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2927          * fails for all new incoming I/O.
2928          */
2929         wait_for_completion(&lun->lun_ref_comp);
2930         /*
2931          * The second completion waits for percpu_ref_put_many() to
2932          * invoke ->release() after lun->lun_ref has switched to
2933          * atomic_t mode, and lun->lun_ref.count has reached zero.
2934          *
2935          * At this point all target-core lun->lun_ref references have
2936          * been dropped via transport_lun_remove_cmd(), and it's safe
2937          * to proceed with the remaining LUN shutdown.
2938          */
2939         wait_for_completion(&lun->lun_shutdown_comp);
2940 }
2941
2942 static bool
2943 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2944                            bool *aborted, bool *tas, unsigned long *flags)
2945         __releases(&cmd->t_state_lock)
2946         __acquires(&cmd->t_state_lock)
2947 {
2948
2949         assert_spin_locked(&cmd->t_state_lock);
2950         WARN_ON_ONCE(!irqs_disabled());
2951
2952         if (fabric_stop)
2953                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2954
2955         if (cmd->transport_state & CMD_T_ABORTED)
2956                 *aborted = true;
2957
2958         if (cmd->transport_state & CMD_T_TAS)
2959                 *tas = true;
2960
2961         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2962             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2963                 return false;
2964
2965         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2966             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2967                 return false;
2968
2969         if (!(cmd->transport_state & CMD_T_ACTIVE))
2970                 return false;
2971
2972         if (fabric_stop && *aborted)
2973                 return false;
2974
2975         cmd->transport_state |= CMD_T_STOP;
2976
2977         target_show_cmd("wait_for_tasks: Stopping ", cmd);
2978
2979         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2980
2981         while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
2982                                             180 * HZ))
2983                 target_show_cmd("wait for tasks: ", cmd);
2984
2985         spin_lock_irqsave(&cmd->t_state_lock, *flags);
2986         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2987
2988         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2989                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2990
2991         return true;
2992 }
2993
2994 /**
2995  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
2996  * @cmd: command to wait on
2997  */
2998 bool transport_wait_for_tasks(struct se_cmd *cmd)
2999 {
3000         unsigned long flags;
3001         bool ret, aborted = false, tas = false;
3002
3003         spin_lock_irqsave(&cmd->t_state_lock, flags);
3004         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3005         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3006
3007         return ret;
3008 }
3009 EXPORT_SYMBOL(transport_wait_for_tasks);
3010
3011 struct sense_info {
3012         u8 key;
3013         u8 asc;
3014         u8 ascq;
3015         bool add_sector_info;
3016 };
3017
3018 static const struct sense_info sense_info_table[] = {
3019         [TCM_NO_SENSE] = {
3020                 .key = NOT_READY
3021         },
3022         [TCM_NON_EXISTENT_LUN] = {
3023                 .key = ILLEGAL_REQUEST,
3024                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3025         },
3026         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
3027                 .key = ILLEGAL_REQUEST,
3028                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3029         },
3030         [TCM_SECTOR_COUNT_TOO_MANY] = {
3031                 .key = ILLEGAL_REQUEST,
3032                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3033         },
3034         [TCM_UNKNOWN_MODE_PAGE] = {
3035                 .key = ILLEGAL_REQUEST,
3036                 .asc = 0x24, /* INVALID FIELD IN CDB */
3037         },
3038         [TCM_CHECK_CONDITION_ABORT_CMD] = {
3039                 .key = ABORTED_COMMAND,
3040                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3041                 .ascq = 0x03,
3042         },
3043         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
3044                 .key = ABORTED_COMMAND,
3045                 .asc = 0x0c, /* WRITE ERROR */
3046                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3047         },
3048         [TCM_INVALID_CDB_FIELD] = {
3049                 .key = ILLEGAL_REQUEST,
3050                 .asc = 0x24, /* INVALID FIELD IN CDB */
3051         },
3052         [TCM_INVALID_PARAMETER_LIST] = {
3053                 .key = ILLEGAL_REQUEST,
3054                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3055         },
3056         [TCM_TOO_MANY_TARGET_DESCS] = {
3057                 .key = ILLEGAL_REQUEST,
3058                 .asc = 0x26,
3059                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3060         },
3061         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3062                 .key = ILLEGAL_REQUEST,
3063                 .asc = 0x26,
3064                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3065         },
3066         [TCM_TOO_MANY_SEGMENT_DESCS] = {
3067                 .key = ILLEGAL_REQUEST,
3068                 .asc = 0x26,
3069                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3070         },
3071         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3072                 .key = ILLEGAL_REQUEST,
3073                 .asc = 0x26,
3074                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3075         },
3076         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3077                 .key = ILLEGAL_REQUEST,
3078                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3079         },
3080         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3081                 .key = ILLEGAL_REQUEST,
3082                 .asc = 0x0c, /* WRITE ERROR */
3083                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3084         },
3085         [TCM_SERVICE_CRC_ERROR] = {
3086                 .key = ABORTED_COMMAND,
3087                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3088                 .ascq = 0x05, /* N/A */
3089         },
3090         [TCM_SNACK_REJECTED] = {
3091                 .key = ABORTED_COMMAND,
3092                 .asc = 0x11, /* READ ERROR */
3093                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3094         },
3095         [TCM_WRITE_PROTECTED] = {
3096                 .key = DATA_PROTECT,
3097                 .asc = 0x27, /* WRITE PROTECTED */
3098         },
3099         [TCM_ADDRESS_OUT_OF_RANGE] = {
3100                 .key = ILLEGAL_REQUEST,
3101                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3102         },
3103         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3104                 .key = UNIT_ATTENTION,
3105         },
3106         [TCM_CHECK_CONDITION_NOT_READY] = {
3107                 .key = NOT_READY,
3108         },
3109         [TCM_MISCOMPARE_VERIFY] = {
3110                 .key = MISCOMPARE,
3111                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3112                 .ascq = 0x00,
3113         },
3114         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3115                 .key = ABORTED_COMMAND,
3116                 .asc = 0x10,
3117                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3118                 .add_sector_info = true,
3119         },
3120         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3121                 .key = ABORTED_COMMAND,
3122                 .asc = 0x10,
3123                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3124                 .add_sector_info = true,
3125         },
3126         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3127                 .key = ABORTED_COMMAND,
3128                 .asc = 0x10,
3129                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3130                 .add_sector_info = true,
3131         },
3132         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3133                 .key = COPY_ABORTED,
3134                 .asc = 0x0d,
3135                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3136
3137         },
3138         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3139                 /*
3140                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
3141                  * Solaris initiators.  Returning NOT READY instead means the
3142                  * operations will be retried a finite number of times and we
3143                  * can survive intermittent errors.
3144                  */
3145                 .key = NOT_READY,
3146                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3147         },
3148 };
3149
3150 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3151 {
3152         const struct sense_info *si;
3153         u8 *buffer = cmd->sense_buffer;
3154         int r = (__force int)reason;
3155         u8 asc, ascq;
3156         bool desc_format = target_sense_desc_format(cmd->se_dev);
3157
3158         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
3159                 si = &sense_info_table[r];
3160         else
3161                 si = &sense_info_table[(__force int)
3162                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3163
3164         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3165                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
3166                 WARN_ON_ONCE(asc == 0);
3167         } else if (si->asc == 0) {
3168                 WARN_ON_ONCE(cmd->scsi_asc == 0);
3169                 asc = cmd->scsi_asc;
3170                 ascq = cmd->scsi_ascq;
3171         } else {
3172                 asc = si->asc;
3173                 ascq = si->ascq;
3174         }
3175
3176         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
3177         if (si->add_sector_info)
3178                 return scsi_set_sense_information(buffer,
3179                                                   cmd->scsi_sense_length,
3180                                                   cmd->bad_sector);
3181
3182         return 0;
3183 }
3184
3185 int
3186 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3187                 sense_reason_t reason, int from_transport)
3188 {
3189         unsigned long flags;
3190
3191         spin_lock_irqsave(&cmd->t_state_lock, flags);
3192         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3193                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3194                 return 0;
3195         }
3196         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3197         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3198
3199         if (!from_transport) {
3200                 int rc;
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                 rc = translate_sense_reason(cmd, reason);
3206                 if (rc)
3207                         return rc;
3208         }
3209
3210         trace_target_cmd_complete(cmd);
3211         return cmd->se_tfo->queue_status(cmd);
3212 }
3213 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3214
3215 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3216         __releases(&cmd->t_state_lock)
3217         __acquires(&cmd->t_state_lock)
3218 {
3219         int ret;
3220
3221         assert_spin_locked(&cmd->t_state_lock);
3222         WARN_ON_ONCE(!irqs_disabled());
3223
3224         if (!(cmd->transport_state & CMD_T_ABORTED))
3225                 return 0;
3226         /*
3227          * If cmd has been aborted but either no status is to be sent or it has
3228          * already been sent, just return
3229          */
3230         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3231                 if (send_status)
3232                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3233                 return 1;
3234         }
3235
3236         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3237                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3238
3239         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3240         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3241         trace_target_cmd_complete(cmd);
3242
3243         spin_unlock_irq(&cmd->t_state_lock);
3244         ret = cmd->se_tfo->queue_status(cmd);
3245         if (ret)
3246                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3247         spin_lock_irq(&cmd->t_state_lock);
3248
3249         return 1;
3250 }
3251
3252 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3253 {
3254         int ret;
3255
3256         spin_lock_irq(&cmd->t_state_lock);
3257         ret = __transport_check_aborted_status(cmd, send_status);
3258         spin_unlock_irq(&cmd->t_state_lock);
3259
3260         return ret;
3261 }
3262 EXPORT_SYMBOL(transport_check_aborted_status);
3263
3264 void transport_send_task_abort(struct se_cmd *cmd)
3265 {
3266         unsigned long flags;
3267         int ret;
3268
3269         spin_lock_irqsave(&cmd->t_state_lock, flags);
3270         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3271                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3272                 return;
3273         }
3274         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3275
3276         /*
3277          * If there are still expected incoming fabric WRITEs, we wait
3278          * until until they have completed before sending a TASK_ABORTED
3279          * response.  This response with TASK_ABORTED status will be
3280          * queued back to fabric module by transport_check_aborted_status().
3281          */
3282         if (cmd->data_direction == DMA_TO_DEVICE) {
3283                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3284                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3285                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3286                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3287                                 goto send_abort;
3288                         }
3289                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3290                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3291                         return;
3292                 }
3293         }
3294 send_abort:
3295         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3296
3297         transport_lun_remove_cmd(cmd);
3298
3299         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3300                  cmd->t_task_cdb[0], cmd->tag);
3301
3302         trace_target_cmd_complete(cmd);
3303         ret = cmd->se_tfo->queue_status(cmd);
3304         if (ret)
3305                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3306 }
3307
3308 static void target_tmr_work(struct work_struct *work)
3309 {
3310         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3311         struct se_device *dev = cmd->se_dev;
3312         struct se_tmr_req *tmr = cmd->se_tmr_req;
3313         unsigned long flags;
3314         int ret;
3315
3316         spin_lock_irqsave(&cmd->t_state_lock, flags);
3317         if (cmd->transport_state & CMD_T_ABORTED) {
3318                 tmr->response = TMR_FUNCTION_REJECTED;
3319                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3320                 goto check_stop;
3321         }
3322         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3323
3324         switch (tmr->function) {
3325         case TMR_ABORT_TASK:
3326                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3327                 break;
3328         case TMR_ABORT_TASK_SET:
3329         case TMR_CLEAR_ACA:
3330         case TMR_CLEAR_TASK_SET:
3331                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3332                 break;
3333         case TMR_LUN_RESET:
3334                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3335                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3336                                          TMR_FUNCTION_REJECTED;
3337                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3338                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3339                                                cmd->orig_fe_lun, 0x29,
3340                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3341                 }
3342                 break;
3343         case TMR_TARGET_WARM_RESET:
3344                 tmr->response = TMR_FUNCTION_REJECTED;
3345                 break;
3346         case TMR_TARGET_COLD_RESET:
3347                 tmr->response = TMR_FUNCTION_REJECTED;
3348                 break;
3349         default:
3350                 pr_err("Uknown TMR function: 0x%02x.\n",
3351                                 tmr->function);
3352                 tmr->response = TMR_FUNCTION_REJECTED;
3353                 break;
3354         }
3355
3356         spin_lock_irqsave(&cmd->t_state_lock, flags);
3357         if (cmd->transport_state & CMD_T_ABORTED) {
3358                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3359                 goto check_stop;
3360         }
3361         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3362
3363         cmd->se_tfo->queue_tm_rsp(cmd);
3364
3365 check_stop:
3366         transport_lun_remove_cmd(cmd);
3367         transport_cmd_check_stop_to_fabric(cmd);
3368 }
3369
3370 int transport_generic_handle_tmr(
3371         struct se_cmd *cmd)
3372 {
3373         unsigned long flags;
3374         bool aborted = false;
3375
3376         spin_lock_irqsave(&cmd->t_state_lock, flags);
3377         if (cmd->transport_state & CMD_T_ABORTED) {
3378                 aborted = true;
3379         } else {
3380                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3381                 cmd->transport_state |= CMD_T_ACTIVE;
3382         }
3383         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3384
3385         if (aborted) {
3386                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3387                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3388                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3389                 transport_lun_remove_cmd(cmd);
3390                 transport_cmd_check_stop_to_fabric(cmd);
3391                 return 0;
3392         }
3393
3394         INIT_WORK(&cmd->work, target_tmr_work);
3395         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3396         return 0;
3397 }
3398 EXPORT_SYMBOL(transport_generic_handle_tmr);
3399
3400 bool
3401 target_check_wce(struct se_device *dev)
3402 {
3403         bool wce = false;
3404
3405         if (dev->transport->get_write_cache)
3406                 wce = dev->transport->get_write_cache(dev);
3407         else if (dev->dev_attrib.emulate_write_cache > 0)
3408                 wce = true;
3409
3410         return wce;
3411 }
3412
3413 bool
3414 target_check_fua(struct se_device *dev)
3415 {
3416         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3417 }