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_REPEAT);
 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(&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(&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 target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 708 {
 709         struct se_device *dev = cmd->se_dev;
 710         int success = scsi_status == GOOD;
 711         unsigned long flags;
 712
 713         cmd->scsi_status = scsi_status;
 714
 715
 716         spin_lock_irqsave(&cmd->t_state_lock, flags);
 717
 718         if (dev && dev->transport->transport_complete) {
 719                 dev->transport->transport_complete(cmd,
 720                                 cmd->t_data_sg,
 721                                 transport_get_sense_buffer(cmd));
 722                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 723                         success = 1;
 724         }
 725
 726         /*
 727          * Check for case where an explicit ABORT_TASK has been received
 728          * and transport_wait_for_tasks() will be waiting for completion..
 729          */
 730         if (cmd->transport_state & CMD_T_ABORTED ||
 731             cmd->transport_state & CMD_T_STOP) {
 732                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 733                 complete_all(&cmd->t_transport_stop_comp);
 734                 return;
 735         } else if (!success) {
 736                 INIT_WORK(&cmd->work, target_complete_failure_work);
 737         } else {
 738                 INIT_WORK(&cmd->work, target_complete_ok_work);
 739         }
 740
 741         cmd->t_state = TRANSPORT_COMPLETE;
 742         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 743         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 744
 745         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 746                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 747         else
 748                 queue_work(target_completion_wq, &cmd->work);
 749 }
 750 EXPORT_SYMBOL(target_complete_cmd);
 751
 752 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 753 {
 754         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 755                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 756                         cmd->residual_count += cmd->data_length - length;
 757                 } else {
 758                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 759                         cmd->residual_count = cmd->data_length - length;
 760                 }
 761
 762                 cmd->data_length = length;
 763         }
 764
 765         target_complete_cmd(cmd, scsi_status);
 766 }
 767 EXPORT_SYMBOL(target_complete_cmd_with_length);
 768
 769 static void target_add_to_state_list(struct se_cmd *cmd)
 770 {
 771         struct se_device *dev = cmd->se_dev;
 772         unsigned long flags;
 773
 774         spin_lock_irqsave(&dev->execute_task_lock, flags);
 775         if (!cmd->state_active) {
 776                 list_add_tail(&cmd->state_list, &dev->state_list);
 777                 cmd->state_active = true;
 778         }
 779         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 780 }
 781
 782 /*
 783  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 784  */
 785 static void transport_write_pending_qf(struct se_cmd *cmd);
 786 static void transport_complete_qf(struct se_cmd *cmd);
 787
 788 void target_qf_do_work(struct work_struct *work)
 789 {
 790         struct se_device *dev = container_of(work, struct se_device,
 791                                         qf_work_queue);
 792         LIST_HEAD(qf_cmd_list);
 793         struct se_cmd *cmd, *cmd_tmp;
 794
 795         spin_lock_irq(&dev->qf_cmd_lock);
 796         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 797         spin_unlock_irq(&dev->qf_cmd_lock);
 798
 799         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 800                 list_del(&cmd->se_qf_node);
 801                 atomic_dec_mb(&dev->dev_qf_count);
 802
 803                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 804                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 805                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 806                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 807                         : "UNKNOWN");
 808
 809                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 810                         transport_write_pending_qf(cmd);
 811                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 812                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 813                         transport_complete_qf(cmd);
 814         }
 815 }
 816
 817 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 818 {
 819         switch (cmd->data_direction) {
 820         case DMA_NONE:
 821                 return "NONE";
 822         case DMA_FROM_DEVICE:
 823                 return "READ";
 824         case DMA_TO_DEVICE:
 825                 return "WRITE";
 826         case DMA_BIDIRECTIONAL:
 827                 return "BIDI";
 828         default:
 829                 break;
 830         }
 831
 832         return "UNKNOWN";
 833 }
 834
 835 void transport_dump_dev_state(
 836         struct se_device *dev,
 837         char *b,
 838         int *bl)
 839 {
 840         *bl += sprintf(b + *bl, "Status: ");
 841         if (dev->export_count)
 842                 *bl += sprintf(b + *bl, "ACTIVATED");
 843         else
 844                 *bl += sprintf(b + *bl, "DEACTIVATED");
 845
 846         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 847         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 848                 dev->dev_attrib.block_size,
 849                 dev->dev_attrib.hw_max_sectors);
 850         *bl += sprintf(b + *bl, "        ");
 851 }
 852
 853 void transport_dump_vpd_proto_id(
 854         struct t10_vpd *vpd,
 855         unsigned char *p_buf,
 856         int p_buf_len)
 857 {
 858         unsigned char buf[VPD_TMP_BUF_SIZE];
 859         int len;
 860
 861         memset(buf, 0, VPD_TMP_BUF_SIZE);
 862         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 863
 864         switch (vpd->protocol_identifier) {
 865         case 0x00:
 866                 sprintf(buf+len, "Fibre Channel\n");
 867                 break;
 868         case 0x10:
 869                 sprintf(buf+len, "Parallel SCSI\n");
 870                 break;
 871         case 0x20:
 872                 sprintf(buf+len, "SSA\n");
 873                 break;
 874         case 0x30:
 875                 sprintf(buf+len, "IEEE 1394\n");
 876                 break;
 877         case 0x40:
 878                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 879                                 " Protocol\n");
 880                 break;
 881         case 0x50:
 882                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 883                 break;
 884         case 0x60:
 885                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 886                 break;
 887         case 0x70:
 888                 sprintf(buf+len, "Automation/Drive Interface Transport"
 889                                 " Protocol\n");
 890                 break;
 891         case 0x80:
 892                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 893                 break;
 894         default:
 895                 sprintf(buf+len, "Unknown 0x%02x\n",
 896                                 vpd->protocol_identifier);
 897                 break;
 898         }
 899
 900         if (p_buf)
 901                 strncpy(p_buf, buf, p_buf_len);
 902         else
 903                 pr_debug("%s", buf);
 904 }
 905
 906 void
 907 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 908 {
 909         /*
 910          * Check if the Protocol Identifier Valid (PIV) bit is set..
 911          *
 912          * from spc3r23.pdf section 7.5.1
 913          */
 914          if (page_83[1] & 0x80) {
 915                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 916                 vpd->protocol_identifier_set = 1;
 917                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 918         }
 919 }
 920 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 921
 922 int transport_dump_vpd_assoc(
 923         struct t10_vpd *vpd,
 924         unsigned char *p_buf,
 925         int p_buf_len)
 926 {
 927         unsigned char buf[VPD_TMP_BUF_SIZE];
 928         int ret = 0;
 929         int len;
 930
 931         memset(buf, 0, VPD_TMP_BUF_SIZE);
 932         len = sprintf(buf, "T10 VPD Identifier Association: ");
 933
 934         switch (vpd->association) {
 935         case 0x00:
 936                 sprintf(buf+len, "addressed logical unit\n");
 937                 break;
 938         case 0x10:
 939                 sprintf(buf+len, "target port\n");
 940                 break;
 941         case 0x20:
 942                 sprintf(buf+len, "SCSI target device\n");
 943                 break;
 944         default:
 945                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 946                 ret = -EINVAL;
 947                 break;
 948         }
 949
 950         if (p_buf)
 951                 strncpy(p_buf, buf, p_buf_len);
 952         else
 953                 pr_debug("%s", buf);
 954
 955         return ret;
 956 }
 957
 958 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 959 {
 960         /*
 961          * The VPD identification association..
 962          *
 963          * from spc3r23.pdf Section 7.6.3.1 Table 297
 964          */
 965         vpd->association = (page_83[1] & 0x30);
 966         return transport_dump_vpd_assoc(vpd, NULL, 0);
 967 }
 968 EXPORT_SYMBOL(transport_set_vpd_assoc);
 969
 970 int transport_dump_vpd_ident_type(
 971         struct t10_vpd *vpd,
 972         unsigned char *p_buf,
 973         int p_buf_len)
 974 {
 975         unsigned char buf[VPD_TMP_BUF_SIZE];
 976         int ret = 0;
 977         int len;
 978
 979         memset(buf, 0, VPD_TMP_BUF_SIZE);
 980         len = sprintf(buf, "T10 VPD Identifier Type: ");
 981
 982         switch (vpd->device_identifier_type) {
 983         case 0x00:
 984                 sprintf(buf+len, "Vendor specific\n");
 985                 break;
 986         case 0x01:
 987                 sprintf(buf+len, "T10 Vendor ID based\n");
 988                 break;
 989         case 0x02:
 990                 sprintf(buf+len, "EUI-64 based\n");
 991                 break;
 992         case 0x03:
 993                 sprintf(buf+len, "NAA\n");
 994                 break;
 995         case 0x04:
 996                 sprintf(buf+len, "Relative target port identifier\n");
 997                 break;
 998         case 0x08:
 999                 sprintf(buf+len, "SCSI name string\n");
1000                 break;
1001         default:
1002                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1003                                 vpd->device_identifier_type);
1004                 ret = -EINVAL;
1005                 break;
1006         }
1007
1008         if (p_buf) {
1009                 if (p_buf_len < strlen(buf)+1)
1010                         return -EINVAL;
1011                 strncpy(p_buf, buf, p_buf_len);
1012         } else {
1013                 pr_debug("%s", buf);
1014         }
1015
1016         return ret;
1017 }
1018
1019 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1020 {
1021         /*
1022          * The VPD identifier type..
1023          *
1024          * from spc3r23.pdf Section 7.6.3.1 Table 298
1025          */
1026         vpd->device_identifier_type = (page_83[1] & 0x0f);
1027         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1028 }
1029 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1030
1031 int transport_dump_vpd_ident(
1032         struct t10_vpd *vpd,
1033         unsigned char *p_buf,
1034         int p_buf_len)
1035 {
1036         unsigned char buf[VPD_TMP_BUF_SIZE];
1037         int ret = 0;
1038
1039         memset(buf, 0, VPD_TMP_BUF_SIZE);
1040
1041         switch (vpd->device_identifier_code_set) {
1042         case 0x01: /* Binary */
1043                 snprintf(buf, sizeof(buf),
1044                         "T10 VPD Binary Device Identifier: %s\n",
1045                         &vpd->device_identifier[0]);
1046                 break;
1047         case 0x02: /* ASCII */
1048                 snprintf(buf, sizeof(buf),
1049                         "T10 VPD ASCII Device Identifier: %s\n",
1050                         &vpd->device_identifier[0]);
1051                 break;
1052         case 0x03: /* UTF-8 */
1053                 snprintf(buf, sizeof(buf),
1054                         "T10 VPD UTF-8 Device Identifier: %s\n",
1055                         &vpd->device_identifier[0]);
1056                 break;
1057         default:
1058                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1059                         " 0x%02x", vpd->device_identifier_code_set);
1060                 ret = -EINVAL;
1061                 break;
1062         }
1063
1064         if (p_buf)
1065                 strncpy(p_buf, buf, p_buf_len);
1066         else
1067                 pr_debug("%s", buf);
1068
1069         return ret;
1070 }
1071
1072 int
1073 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1074 {
1075         static const char hex_str[] = "0123456789abcdef";
1076         int j = 0, i = 4; /* offset to start of the identifier */
1077
1078         /*
1079          * The VPD Code Set (encoding)
1080          *
1081          * from spc3r23.pdf Section 7.6.3.1 Table 296
1082          */
1083         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1084         switch (vpd->device_identifier_code_set) {
1085         case 0x01: /* Binary */
1086                 vpd->device_identifier[j++] =
1087                                 hex_str[vpd->device_identifier_type];
1088                 while (i < (4 + page_83[3])) {
1089                         vpd->device_identifier[j++] =
1090                                 hex_str[(page_83[i] & 0xf0) >> 4];
1091                         vpd->device_identifier[j++] =
1092                                 hex_str[page_83[i] & 0x0f];
1093                         i++;
1094                 }
1095                 break;
1096         case 0x02: /* ASCII */
1097         case 0x03: /* UTF-8 */
1098                 while (i < (4 + page_83[3]))
1099                         vpd->device_identifier[j++] = page_83[i++];
1100                 break;
1101         default:
1102                 break;
1103         }
1104
1105         return transport_dump_vpd_ident(vpd, NULL, 0);
1106 }
1107 EXPORT_SYMBOL(transport_set_vpd_ident);
1108
1109 static sense_reason_t
1110 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1111                                unsigned int size)
1112 {
1113         u32 mtl;
1114
1115         if (!cmd->se_tfo->max_data_sg_nents)
1116                 return TCM_NO_SENSE;
1117         /*
1118          * Check if fabric enforced maximum SGL entries per I/O descriptor
1119          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1120          * residual_count and reduce original cmd->data_length to maximum
1121          * length based on single PAGE_SIZE entry scatter-lists.
1122          */
1123         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1124         if (cmd->data_length > mtl) {
1125                 /*
1126                  * If an existing CDB overflow is present, calculate new residual
1127                  * based on CDB size minus fabric maximum transfer length.
1128                  *
1129                  * If an existing CDB underflow is present, calculate new residual
1130                  * based on original cmd->data_length minus fabric maximum transfer
1131                  * length.
1132                  *
1133                  * Otherwise, set the underflow residual based on cmd->data_length
1134                  * minus fabric maximum transfer length.
1135                  */
1136                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1137                         cmd->residual_count = (size - mtl);
1138                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1139                         u32 orig_dl = size + cmd->residual_count;
1140                         cmd->residual_count = (orig_dl - mtl);
1141                 } else {
1142                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1143                         cmd->residual_count = (cmd->data_length - mtl);
1144                 }
1145                 cmd->data_length = mtl;
1146                 /*
1147                  * Reset sbc_check_prot() calculated protection payload
1148                  * length based upon the new smaller MTL.
1149                  */
1150                 if (cmd->prot_length) {
1151                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1152                         cmd->prot_length = dev->prot_length * sectors;
1153                 }
1154         }
1155         return TCM_NO_SENSE;
1156 }
1157
1158 sense_reason_t
1159 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1160 {
1161         struct se_device *dev = cmd->se_dev;
1162
1163         if (cmd->unknown_data_length) {
1164                 cmd->data_length = size;
1165         } else if (size != cmd->data_length) {
1166                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1167                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1168                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1169                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1170
1171                 if (cmd->data_direction == DMA_TO_DEVICE) {
1172                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1173                                 pr_err_ratelimited("Rejecting underflow/overflow"
1174                                                    " for WRITE data CDB\n");
1175                                 return TCM_INVALID_CDB_FIELD;
1176                         }
1177                         /*
1178                          * Some fabric drivers like iscsi-target still expect to
1179                          * always reject overflow writes.  Reject this case until
1180                          * full fabric driver level support for overflow writes
1181                          * is introduced tree-wide.
1182                          */
1183                         if (size > cmd->data_length) {
1184                                 pr_err_ratelimited("Rejecting overflow for"
1185                                                    " WRITE control CDB\n");
1186                                 return TCM_INVALID_CDB_FIELD;
1187                         }
1188                 }
1189                 /*
1190                  * Reject READ_* or WRITE_* with overflow/underflow for
1191                  * type SCF_SCSI_DATA_CDB.
1192                  */
1193                 if (dev->dev_attrib.block_size != 512)  {
1194                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1195                                 " CDB on non 512-byte sector setup subsystem"
1196                                 " plugin: %s\n", dev->transport->name);
1197                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1198                         return TCM_INVALID_CDB_FIELD;
1199                 }
1200                 /*
1201                  * For the overflow case keep the existing fabric provided
1202                  * ->data_length.  Otherwise for the underflow case, reset
1203                  * ->data_length to the smaller SCSI expected data transfer
1204                  * length.
1205                  */
1206                 if (size > cmd->data_length) {
1207                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1208                         cmd->residual_count = (size - cmd->data_length);
1209                 } else {
1210                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1211                         cmd->residual_count = (cmd->data_length - size);
1212                         cmd->data_length = size;
1213                 }
1214         }
1215
1216         return target_check_max_data_sg_nents(cmd, dev, size);
1217
1218 }
1219
1220 /*
1221  * Used by fabric modules containing a local struct se_cmd within their
1222  * fabric dependent per I/O descriptor.
1223  *
1224  * Preserves the value of @cmd->tag.
1225  */
1226 void transport_init_se_cmd(
1227         struct se_cmd *cmd,
1228         const struct target_core_fabric_ops *tfo,
1229         struct se_session *se_sess,
1230         u32 data_length,
1231         int data_direction,
1232         int task_attr,
1233         unsigned char *sense_buffer)
1234 {
1235         INIT_LIST_HEAD(&cmd->se_delayed_node);
1236         INIT_LIST_HEAD(&cmd->se_qf_node);
1237         INIT_LIST_HEAD(&cmd->se_cmd_list);
1238         INIT_LIST_HEAD(&cmd->state_list);
1239         init_completion(&cmd->t_transport_stop_comp);
1240         init_completion(&cmd->cmd_wait_comp);
1241         spin_lock_init(&cmd->t_state_lock);
1242         kref_init(&cmd->cmd_kref);
1243
1244         cmd->se_tfo = tfo;
1245         cmd->se_sess = se_sess;
1246         cmd->data_length = data_length;
1247         cmd->data_direction = data_direction;
1248         cmd->sam_task_attr = task_attr;
1249         cmd->sense_buffer = sense_buffer;
1250
1251         cmd->state_active = false;
1252 }
1253 EXPORT_SYMBOL(transport_init_se_cmd);
1254
1255 static sense_reason_t
1256 transport_check_alloc_task_attr(struct se_cmd *cmd)
1257 {
1258         struct se_device *dev = cmd->se_dev;
1259
1260         /*
1261          * Check if SAM Task Attribute emulation is enabled for this
1262          * struct se_device storage object
1263          */
1264         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1265                 return 0;
1266
1267         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1268                 pr_debug("SAM Task Attribute ACA"
1269                         " emulation is not supported\n");
1270                 return TCM_INVALID_CDB_FIELD;
1271         }
1272
1273         return 0;
1274 }
1275
1276 sense_reason_t
1277 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1278 {
1279         struct se_device *dev = cmd->se_dev;
1280         sense_reason_t ret;
1281
1282         /*
1283          * Ensure that the received CDB is less than the max (252 + 8) bytes
1284          * for VARIABLE_LENGTH_CMD
1285          */
1286         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1287                 pr_err("Received SCSI CDB with command_size: %d that"
1288                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1289                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1290                 return TCM_INVALID_CDB_FIELD;
1291         }
1292         /*
1293          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1294          * allocate the additional extended CDB buffer now..  Otherwise
1295          * setup the pointer from __t_task_cdb to t_task_cdb.
1296          */
1297         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1298                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1299                                                 GFP_KERNEL);
1300                 if (!cmd->t_task_cdb) {
1301                         pr_err("Unable to allocate cmd->t_task_cdb"
1302                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1303                                 scsi_command_size(cdb),
1304                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1305                         return TCM_OUT_OF_RESOURCES;
1306                 }
1307         } else
1308                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1309         /*
1310          * Copy the original CDB into cmd->
1311          */
1312         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1313
1314         trace_target_sequencer_start(cmd);
1315
1316         ret = dev->transport->parse_cdb(cmd);
1317         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1318                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1319                                     cmd->se_tfo->get_fabric_name(),
1320                                     cmd->se_sess->se_node_acl->initiatorname,
1321                                     cmd->t_task_cdb[0]);
1322         if (ret)
1323                 return ret;
1324
1325         ret = transport_check_alloc_task_attr(cmd);
1326         if (ret)
1327                 return ret;
1328
1329         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1330         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1331         return 0;
1332 }
1333 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1334
1335 /*
1336  * Used by fabric module frontends to queue tasks directly.
1337  * May only be used from process context.
1338  */
1339 int transport_handle_cdb_direct(
1340         struct se_cmd *cmd)
1341 {
1342         sense_reason_t ret;
1343
1344         if (!cmd->se_lun) {
1345                 dump_stack();
1346                 pr_err("cmd->se_lun is NULL\n");
1347                 return -EINVAL;
1348         }
1349         if (in_interrupt()) {
1350                 dump_stack();
1351                 pr_err("transport_generic_handle_cdb cannot be called"
1352                                 " from interrupt context\n");
1353                 return -EINVAL;
1354         }
1355         /*
1356          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1357          * outstanding descriptors are handled correctly during shutdown via
1358          * transport_wait_for_tasks()
1359          *
1360          * Also, we don't take cmd->t_state_lock here as we only expect
1361          * this to be called for initial descriptor submission.
1362          */
1363         cmd->t_state = TRANSPORT_NEW_CMD;
1364         cmd->transport_state |= CMD_T_ACTIVE;
1365
1366         /*
1367          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1368          * so follow TRANSPORT_NEW_CMD processing thread context usage
1369          * and call transport_generic_request_failure() if necessary..
1370          */
1371         ret = transport_generic_new_cmd(cmd);
1372         if (ret)
1373                 transport_generic_request_failure(cmd, ret);
1374         return 0;
1375 }
1376 EXPORT_SYMBOL(transport_handle_cdb_direct);
1377
1378 sense_reason_t
1379 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1380                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1381 {
1382         if (!sgl || !sgl_count)
1383                 return 0;
1384
1385         /*
1386          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1387          * scatterlists already have been set to follow what the fabric
1388          * passes for the original expected data transfer length.
1389          */
1390         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1391                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1392                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1393                 return TCM_INVALID_CDB_FIELD;
1394         }
1395
1396         cmd->t_data_sg = sgl;
1397         cmd->t_data_nents = sgl_count;
1398         cmd->t_bidi_data_sg = sgl_bidi;
1399         cmd->t_bidi_data_nents = sgl_bidi_count;
1400
1401         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1402         return 0;
1403 }
1404
1405 /*
1406  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1407  *                       se_cmd + use pre-allocated SGL memory.
1408  *
1409  * @se_cmd: command descriptor to submit
1410  * @se_sess: associated se_sess for endpoint
1411  * @cdb: pointer to SCSI CDB
1412  * @sense: pointer to SCSI sense buffer
1413  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1414  * @data_length: fabric expected data transfer length
1415  * @task_addr: SAM task attribute
1416  * @data_dir: DMA data direction
1417  * @flags: flags for command submission from target_sc_flags_tables
1418  * @sgl: struct scatterlist memory for unidirectional mapping
1419  * @sgl_count: scatterlist count for unidirectional mapping
1420  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1421  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1422  * @sgl_prot: struct scatterlist memory protection information
1423  * @sgl_prot_count: scatterlist count for protection information
1424  *
1425  * Task tags are supported if the caller has set @se_cmd->tag.
1426  *
1427  * Returns non zero to signal active I/O shutdown failure.  All other
1428  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1429  * but still return zero here.
1430  *
1431  * This may only be called from process context, and also currently
1432  * assumes internal allocation of fabric payload buffer by target-core.
1433  */
1434 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1435                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1436                 u32 data_length, int task_attr, int data_dir, int flags,
1437                 struct scatterlist *sgl, u32 sgl_count,
1438                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1439                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1440 {
1441         struct se_portal_group *se_tpg;
1442         sense_reason_t rc;
1443         int ret;
1444
1445         se_tpg = se_sess->se_tpg;
1446         BUG_ON(!se_tpg);
1447         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1448         BUG_ON(in_interrupt());
1449         /*
1450          * Initialize se_cmd for target operation.  From this point
1451          * exceptions are handled by sending exception status via
1452          * target_core_fabric_ops->queue_status() callback
1453          */
1454         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1455                                 data_length, data_dir, task_attr, sense);
1456
1457         if (flags & TARGET_SCF_USE_CPUID)
1458                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1459         else
1460                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1461
1462         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1463                 se_cmd->unknown_data_length = 1;
1464         /*
1465          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1466          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1467          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1468          * kref_put() to happen during fabric packet acknowledgement.
1469          */
1470         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1471         if (ret)
1472                 return ret;
1473         /*
1474          * Signal bidirectional data payloads to target-core
1475          */
1476         if (flags & TARGET_SCF_BIDI_OP)
1477                 se_cmd->se_cmd_flags |= SCF_BIDI;
1478         /*
1479          * Locate se_lun pointer and attach it to struct se_cmd
1480          */
1481         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1482         if (rc) {
1483                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1484                 target_put_sess_cmd(se_cmd);
1485                 return 0;
1486         }
1487
1488         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1489         if (rc != 0) {
1490                 transport_generic_request_failure(se_cmd, rc);
1491                 return 0;
1492         }
1493
1494         /*
1495          * Save pointers for SGLs containing protection information,
1496          * if present.
1497          */
1498         if (sgl_prot_count) {
1499                 se_cmd->t_prot_sg = sgl_prot;
1500                 se_cmd->t_prot_nents = sgl_prot_count;
1501                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1502         }
1503
1504         /*
1505          * When a non zero sgl_count has been passed perform SGL passthrough
1506          * mapping for pre-allocated fabric memory instead of having target
1507          * core perform an internal SGL allocation..
1508          */
1509         if (sgl_count != 0) {
1510                 BUG_ON(!sgl);
1511
1512                 /*
1513                  * A work-around for tcm_loop as some userspace code via
1514                  * scsi-generic do not memset their associated read buffers,
1515                  * so go ahead and do that here for type non-data CDBs.  Also
1516                  * note that this is currently guaranteed to be a single SGL
1517                  * for this case by target core in target_setup_cmd_from_cdb()
1518                  * -> transport_generic_cmd_sequencer().
1519                  */
1520                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1521                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1522                         unsigned char *buf = NULL;
1523
1524                         if (sgl)
1525                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1526
1527                         if (buf) {
1528                                 memset(buf, 0, sgl->length);
1529                                 kunmap(sg_page(sgl));
1530                         }
1531                 }
1532
1533                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1534                                 sgl_bidi, sgl_bidi_count);
1535                 if (rc != 0) {
1536                         transport_generic_request_failure(se_cmd, rc);
1537                         return 0;
1538                 }
1539         }
1540
1541         /*
1542          * Check if we need to delay processing because of ALUA
1543          * Active/NonOptimized primary access state..
1544          */
1545         core_alua_check_nonop_delay(se_cmd);
1546
1547         transport_handle_cdb_direct(se_cmd);
1548         return 0;
1549 }
1550 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1551
1552 /*
1553  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1554  *
1555  * @se_cmd: command descriptor to submit
1556  * @se_sess: associated se_sess for endpoint
1557  * @cdb: pointer to SCSI CDB
1558  * @sense: pointer to SCSI sense buffer
1559  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1560  * @data_length: fabric expected data transfer length
1561  * @task_addr: SAM task attribute
1562  * @data_dir: DMA data direction
1563  * @flags: flags for command submission from target_sc_flags_tables
1564  *
1565  * Task tags are supported if the caller has set @se_cmd->tag.
1566  *
1567  * Returns non zero to signal active I/O shutdown failure.  All other
1568  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1569  * but still return zero here.
1570  *
1571  * This may only be called from process context, and also currently
1572  * assumes internal allocation of fabric payload buffer by target-core.
1573  *
1574  * It also assumes interal target core SGL memory allocation.
1575  */
1576 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1577                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1578                 u32 data_length, int task_attr, int data_dir, int flags)
1579 {
1580         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1581                         unpacked_lun, data_length, task_attr, data_dir,
1582                         flags, NULL, 0, NULL, 0, NULL, 0);
1583 }
1584 EXPORT_SYMBOL(target_submit_cmd);
1585
1586 static void target_complete_tmr_failure(struct work_struct *work)
1587 {
1588         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1589
1590         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1591         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1592
1593         transport_cmd_check_stop_to_fabric(se_cmd);
1594 }
1595
1596 /**
1597  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1598  *                     for TMR CDBs
1599  *
1600  * @se_cmd: command descriptor to submit
1601  * @se_sess: associated se_sess for endpoint
1602  * @sense: pointer to SCSI sense buffer
1603  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1604  * @fabric_context: fabric context for TMR req
1605  * @tm_type: Type of TM request
1606  * @gfp: gfp type for caller
1607  * @tag: referenced task tag for TMR_ABORT_TASK
1608  * @flags: submit cmd flags
1609  *
1610  * Callable from all contexts.
1611  **/
1612
1613 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1614                 unsigned char *sense, u64 unpacked_lun,
1615                 void *fabric_tmr_ptr, unsigned char tm_type,
1616                 gfp_t gfp, u64 tag, int flags)
1617 {
1618         struct se_portal_group *se_tpg;
1619         int ret;
1620
1621         se_tpg = se_sess->se_tpg;
1622         BUG_ON(!se_tpg);
1623
1624         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1625                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1626         /*
1627          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1628          * allocation failure.
1629          */
1630         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1631         if (ret < 0)
1632                 return -ENOMEM;
1633
1634         if (tm_type == TMR_ABORT_TASK)
1635                 se_cmd->se_tmr_req->ref_task_tag = tag;
1636
1637         /* See target_submit_cmd for commentary */
1638         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1639         if (ret) {
1640                 core_tmr_release_req(se_cmd->se_tmr_req);
1641                 return ret;
1642         }
1643
1644         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1645         if (ret) {
1646                 /*
1647                  * For callback during failure handling, push this work off
1648                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1649                  */
1650                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1651                 schedule_work(&se_cmd->work);
1652                 return 0;
1653         }
1654         transport_generic_handle_tmr(se_cmd);
1655         return 0;
1656 }
1657 EXPORT_SYMBOL(target_submit_tmr);
1658
1659 /*
1660  * Handle SAM-esque emulation for generic transport request failures.
1661  */
1662 void transport_generic_request_failure(struct se_cmd *cmd,
1663                 sense_reason_t sense_reason)
1664 {
1665         int ret = 0, post_ret = 0;
1666
1667         if (transport_check_aborted_status(cmd, 1))
1668                 return;
1669
1670         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1671                 " CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1672         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1673                 cmd->se_tfo->get_cmd_state(cmd),
1674                 cmd->t_state, sense_reason);
1675         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1676                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1677                 (cmd->transport_state & CMD_T_STOP) != 0,
1678                 (cmd->transport_state & CMD_T_SENT) != 0);
1679
1680         /*
1681          * For SAM Task Attribute emulation for failed struct se_cmd
1682          */
1683         transport_complete_task_attr(cmd);
1684         /*
1685          * Handle special case for COMPARE_AND_WRITE failure, where the
1686          * callback is expected to drop the per device ->caw_sem.
1687          */
1688         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1689              cmd->transport_complete_callback)
1690                 cmd->transport_complete_callback(cmd, false, &post_ret);
1691
1692         switch (sense_reason) {
1693         case TCM_NON_EXISTENT_LUN:
1694         case TCM_UNSUPPORTED_SCSI_OPCODE:
1695         case TCM_INVALID_CDB_FIELD:
1696         case TCM_INVALID_PARAMETER_LIST:
1697         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1698         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1699         case TCM_UNKNOWN_MODE_PAGE:
1700         case TCM_WRITE_PROTECTED:
1701         case TCM_ADDRESS_OUT_OF_RANGE:
1702         case TCM_CHECK_CONDITION_ABORT_CMD:
1703         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1704         case TCM_CHECK_CONDITION_NOT_READY:
1705         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1706         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1707         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1708         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1709         case TCM_TOO_MANY_TARGET_DESCS:
1710         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1711         case TCM_TOO_MANY_SEGMENT_DESCS:
1712         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1713                 break;
1714         case TCM_OUT_OF_RESOURCES:
1715                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1716                 break;
1717         case TCM_RESERVATION_CONFLICT:
1718                 /*
1719                  * No SENSE Data payload for this case, set SCSI Status
1720                  * and queue the response to $FABRIC_MOD.
1721                  *
1722                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1723                  */
1724                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1725                 /*
1726                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1727                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1728                  * CONFLICT STATUS.
1729                  *
1730                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1731                  */
1732                 if (cmd->se_sess &&
1733                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1734                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1735                                                cmd->orig_fe_lun, 0x2C,
1736                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1737                 }
1738                 trace_target_cmd_complete(cmd);
1739                 ret = cmd->se_tfo->queue_status(cmd);
1740                 if (ret)
1741                         goto queue_full;
1742                 goto check_stop;
1743         default:
1744                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1745                         cmd->t_task_cdb[0], sense_reason);
1746                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1747                 break;
1748         }
1749
1750         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1751         if (ret)
1752                 goto queue_full;
1753
1754 check_stop:
1755         transport_lun_remove_cmd(cmd);
1756         transport_cmd_check_stop_to_fabric(cmd);
1757         return;
1758
1759 queue_full:
1760         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1761 }
1762 EXPORT_SYMBOL(transport_generic_request_failure);
1763
1764 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1765 {
1766         sense_reason_t ret;
1767
1768         if (!cmd->execute_cmd) {
1769                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1770                 goto err;
1771         }
1772         if (do_checks) {
1773                 /*
1774                  * Check for an existing UNIT ATTENTION condition after
1775                  * target_handle_task_attr() has done SAM task attr
1776                  * checking, and possibly have already defered execution
1777                  * out to target_restart_delayed_cmds() context.
1778                  */
1779                 ret = target_scsi3_ua_check(cmd);
1780                 if (ret)
1781                         goto err;
1782
1783                 ret = target_alua_state_check(cmd);
1784                 if (ret)
1785                         goto err;
1786
1787                 ret = target_check_reservation(cmd);
1788                 if (ret) {
1789                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1790                         goto err;
1791                 }
1792         }
1793
1794         ret = cmd->execute_cmd(cmd);
1795         if (!ret)
1796                 return;
1797 err:
1798         spin_lock_irq(&cmd->t_state_lock);
1799         cmd->transport_state &= ~CMD_T_SENT;
1800         spin_unlock_irq(&cmd->t_state_lock);
1801
1802         transport_generic_request_failure(cmd, ret);
1803 }
1804
1805 static int target_write_prot_action(struct se_cmd *cmd)
1806 {
1807         u32 sectors;
1808         /*
1809          * Perform WRITE_INSERT of PI using software emulation when backend
1810          * device has PI enabled, if the transport has not already generated
1811          * PI using hardware WRITE_INSERT offload.
1812          */
1813         switch (cmd->prot_op) {
1814         case TARGET_PROT_DOUT_INSERT:
1815                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1816                         sbc_dif_generate(cmd);
1817                 break;
1818         case TARGET_PROT_DOUT_STRIP:
1819                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1820                         break;
1821
1822                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1823                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1824                                              sectors, 0, cmd->t_prot_sg, 0);
1825                 if (unlikely(cmd->pi_err)) {
1826                         spin_lock_irq(&cmd->t_state_lock);
1827                         cmd->transport_state &= ~CMD_T_SENT;
1828                         spin_unlock_irq(&cmd->t_state_lock);
1829                         transport_generic_request_failure(cmd, cmd->pi_err);
1830                         return -1;
1831                 }
1832                 break;
1833         default:
1834                 break;
1835         }
1836
1837         return 0;
1838 }
1839
1840 static bool target_handle_task_attr(struct se_cmd *cmd)
1841 {
1842         struct se_device *dev = cmd->se_dev;
1843
1844         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1845                 return false;
1846
1847         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1848
1849         /*
1850          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1851          * to allow the passed struct se_cmd list of tasks to the front of the list.
1852          */
1853         switch (cmd->sam_task_attr) {
1854         case TCM_HEAD_TAG:
1855                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1856                          cmd->t_task_cdb[0]);
1857                 return false;
1858         case TCM_ORDERED_TAG:
1859                 atomic_inc_mb(&dev->dev_ordered_sync);
1860
1861                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1862                          cmd->t_task_cdb[0]);
1863
1864                 /*
1865                  * Execute an ORDERED command if no other older commands
1866                  * exist that need to be completed first.
1867                  */
1868                 if (!atomic_read(&dev->simple_cmds))
1869                         return false;
1870                 break;
1871         default:
1872                 /*
1873                  * For SIMPLE and UNTAGGED Task Attribute commands
1874                  */
1875                 atomic_inc_mb(&dev->simple_cmds);
1876                 break;
1877         }
1878
1879         if (atomic_read(&dev->dev_ordered_sync) == 0)
1880                 return false;
1881
1882         spin_lock(&dev->delayed_cmd_lock);
1883         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1884         spin_unlock(&dev->delayed_cmd_lock);
1885
1886         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1887                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1888         return true;
1889 }
1890
1891 static int __transport_check_aborted_status(struct se_cmd *, int);
1892
1893 void target_execute_cmd(struct se_cmd *cmd)
1894 {
1895         /*
1896          * Determine if frontend context caller is requesting the stopping of
1897          * this command for frontend exceptions.
1898          *
1899          * If the received CDB has aleady been aborted stop processing it here.
1900          */
1901         spin_lock_irq(&cmd->t_state_lock);
1902         if (__transport_check_aborted_status(cmd, 1)) {
1903                 spin_unlock_irq(&cmd->t_state_lock);
1904                 return;
1905         }
1906         if (cmd->transport_state & CMD_T_STOP) {
1907                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1908                         __func__, __LINE__, cmd->tag);
1909
1910                 spin_unlock_irq(&cmd->t_state_lock);
1911                 complete_all(&cmd->t_transport_stop_comp);
1912                 return;
1913         }
1914
1915         cmd->t_state = TRANSPORT_PROCESSING;
1916         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
1917         spin_unlock_irq(&cmd->t_state_lock);
1918
1919         if (target_write_prot_action(cmd))
1920                 return;
1921
1922         if (target_handle_task_attr(cmd)) {
1923                 spin_lock_irq(&cmd->t_state_lock);
1924                 cmd->transport_state &= ~CMD_T_SENT;
1925                 spin_unlock_irq(&cmd->t_state_lock);
1926                 return;
1927         }
1928
1929         __target_execute_cmd(cmd, true);
1930 }
1931 EXPORT_SYMBOL(target_execute_cmd);
1932
1933 /*
1934  * Process all commands up to the last received ORDERED task attribute which
1935  * requires another blocking boundary
1936  */
1937 static void target_restart_delayed_cmds(struct se_device *dev)
1938 {
1939         for (;;) {
1940                 struct se_cmd *cmd;
1941
1942                 spin_lock(&dev->delayed_cmd_lock);
1943                 if (list_empty(&dev->delayed_cmd_list)) {
1944                         spin_unlock(&dev->delayed_cmd_lock);
1945                         break;
1946                 }
1947
1948                 cmd = list_entry(dev->delayed_cmd_list.next,
1949                                  struct se_cmd, se_delayed_node);
1950                 list_del(&cmd->se_delayed_node);
1951                 spin_unlock(&dev->delayed_cmd_lock);
1952
1953                 __target_execute_cmd(cmd, true);
1954
1955                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1956                         break;
1957         }
1958 }
1959
1960 /*
1961  * Called from I/O completion to determine which dormant/delayed
1962  * and ordered cmds need to have their tasks added to the execution queue.
1963  */
1964 static void transport_complete_task_attr(struct se_cmd *cmd)
1965 {
1966         struct se_device *dev = cmd->se_dev;
1967
1968         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1969                 return;
1970
1971         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
1972                 goto restart;
1973
1974         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1975                 atomic_dec_mb(&dev->simple_cmds);
1976                 dev->dev_cur_ordered_id++;
1977         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1978                 dev->dev_cur_ordered_id++;
1979                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1980                          dev->dev_cur_ordered_id);
1981         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1982                 atomic_dec_mb(&dev->dev_ordered_sync);
1983
1984                 dev->dev_cur_ordered_id++;
1985                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1986                          dev->dev_cur_ordered_id);
1987         }
1988 restart:
1989         target_restart_delayed_cmds(dev);
1990 }
1991
1992 static void transport_complete_qf(struct se_cmd *cmd)
1993 {
1994         int ret = 0;
1995
1996         transport_complete_task_attr(cmd);
1997         /*
1998          * If a fabric driver ->write_pending() or ->queue_data_in() callback
1999          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2000          * the same callbacks should not be retried.  Return CHECK_CONDITION
2001          * if a scsi_status is not already set.
2002          *
2003          * If a fabric driver ->queue_status() has returned non zero, always
2004          * keep retrying no matter what..
2005          */
2006         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2007                 if (cmd->scsi_status)
2008                         goto queue_status;
2009
2010                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2011                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2012                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2013                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2014                 goto queue_status;
2015         }
2016
2017         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2018                 goto queue_status;
2019
2020         switch (cmd->data_direction) {
2021         case DMA_FROM_DEVICE:
2022                 if (cmd->scsi_status)
2023                         goto queue_status;
2024
2025                 trace_target_cmd_complete(cmd);
2026                 ret = cmd->se_tfo->queue_data_in(cmd);
2027                 break;
2028         case DMA_TO_DEVICE:
2029                 if (cmd->se_cmd_flags & SCF_BIDI) {
2030                         ret = cmd->se_tfo->queue_data_in(cmd);
2031                         break;
2032                 }
2033                 /* Fall through for DMA_TO_DEVICE */
2034         case DMA_NONE:
2035 queue_status:
2036                 trace_target_cmd_complete(cmd);
2037                 ret = cmd->se_tfo->queue_status(cmd);
2038                 break;
2039         default:
2040                 break;
2041         }
2042
2043         if (ret < 0) {
2044                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2045                 return;
2046         }
2047         transport_lun_remove_cmd(cmd);
2048         transport_cmd_check_stop_to_fabric(cmd);
2049 }
2050
2051 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2052                                         int err, bool write_pending)
2053 {
2054         /*
2055          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2056          * ->queue_data_in() callbacks from new process context.
2057          *
2058          * Otherwise for other errors, transport_complete_qf() will send
2059          * CHECK_CONDITION via ->queue_status() instead of attempting to
2060          * retry associated fabric driver data-transfer callbacks.
2061          */
2062         if (err == -EAGAIN || err == -ENOMEM) {
2063                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2064                                                  TRANSPORT_COMPLETE_QF_OK;
2065         } else {
2066                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2067                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2068         }
2069
2070         spin_lock_irq(&dev->qf_cmd_lock);
2071         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2072         atomic_inc_mb(&dev->dev_qf_count);
2073         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2074
2075         schedule_work(&cmd->se_dev->qf_work_queue);
2076 }
2077
2078 static bool target_read_prot_action(struct se_cmd *cmd)
2079 {
2080         switch (cmd->prot_op) {
2081         case TARGET_PROT_DIN_STRIP:
2082                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2083                         u32 sectors = cmd->data_length >>
2084                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2085
2086                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2087                                                      sectors, 0, cmd->t_prot_sg,
2088                                                      0);
2089                         if (cmd->pi_err)
2090                                 return true;
2091                 }
2092                 break;
2093         case TARGET_PROT_DIN_INSERT:
2094                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2095                         break;
2096
2097                 sbc_dif_generate(cmd);
2098                 break;
2099         default:
2100                 break;
2101         }
2102
2103         return false;
2104 }
2105
2106 static void target_complete_ok_work(struct work_struct *work)
2107 {
2108         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2109         int ret;
2110
2111         /*
2112          * Check if we need to move delayed/dormant tasks from cmds on the
2113          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2114          * Attribute.
2115          */
2116         transport_complete_task_attr(cmd);
2117
2118         /*
2119          * Check to schedule QUEUE_FULL work, or execute an existing
2120          * cmd->transport_qf_callback()
2121          */
2122         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2123                 schedule_work(&cmd->se_dev->qf_work_queue);
2124
2125         /*
2126          * Check if we need to send a sense buffer from
2127          * the struct se_cmd in question.
2128          */
2129         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2130                 WARN_ON(!cmd->scsi_status);
2131                 ret = transport_send_check_condition_and_sense(
2132                                         cmd, 0, 1);
2133                 if (ret)
2134                         goto queue_full;
2135
2136                 transport_lun_remove_cmd(cmd);
2137                 transport_cmd_check_stop_to_fabric(cmd);
2138                 return;
2139         }
2140         /*
2141          * Check for a callback, used by amongst other things
2142          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2143          */
2144         if (cmd->transport_complete_callback) {
2145                 sense_reason_t rc;
2146                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2147                 bool zero_dl = !(cmd->data_length);
2148                 int post_ret = 0;
2149
2150                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2151                 if (!rc && !post_ret) {
2152                         if (caw && zero_dl)
2153                                 goto queue_rsp;
2154
2155                         return;
2156                 } else if (rc) {
2157                         ret = transport_send_check_condition_and_sense(cmd,
2158                                                 rc, 0);
2159                         if (ret)
2160                                 goto queue_full;
2161
2162                         transport_lun_remove_cmd(cmd);
2163                         transport_cmd_check_stop_to_fabric(cmd);
2164                         return;
2165                 }
2166         }
2167
2168 queue_rsp:
2169         switch (cmd->data_direction) {
2170         case DMA_FROM_DEVICE:
2171                 if (cmd->scsi_status)
2172                         goto queue_status;
2173
2174                 atomic_long_add(cmd->data_length,
2175                                 &cmd->se_lun->lun_stats.tx_data_octets);
2176                 /*
2177                  * Perform READ_STRIP of PI using software emulation when
2178                  * backend had PI enabled, if the transport will not be
2179                  * performing hardware READ_STRIP offload.
2180                  */
2181                 if (target_read_prot_action(cmd)) {
2182                         ret = transport_send_check_condition_and_sense(cmd,
2183                                                 cmd->pi_err, 0);
2184                         if (ret)
2185                                 goto queue_full;
2186
2187                         transport_lun_remove_cmd(cmd);
2188                         transport_cmd_check_stop_to_fabric(cmd);
2189                         return;
2190                 }
2191
2192                 trace_target_cmd_complete(cmd);
2193                 ret = cmd->se_tfo->queue_data_in(cmd);
2194                 if (ret)
2195                         goto queue_full;
2196                 break;
2197         case DMA_TO_DEVICE:
2198                 atomic_long_add(cmd->data_length,
2199                                 &cmd->se_lun->lun_stats.rx_data_octets);
2200                 /*
2201                  * Check if we need to send READ payload for BIDI-COMMAND
2202                  */
2203                 if (cmd->se_cmd_flags & SCF_BIDI) {
2204                         atomic_long_add(cmd->data_length,
2205                                         &cmd->se_lun->lun_stats.tx_data_octets);
2206                         ret = cmd->se_tfo->queue_data_in(cmd);
2207                         if (ret)
2208                                 goto queue_full;
2209                         break;
2210                 }
2211                 /* Fall through for DMA_TO_DEVICE */
2212         case DMA_NONE:
2213 queue_status:
2214                 trace_target_cmd_complete(cmd);
2215                 ret = cmd->se_tfo->queue_status(cmd);
2216                 if (ret)
2217                         goto queue_full;
2218                 break;
2219         default:
2220                 break;
2221         }
2222
2223         transport_lun_remove_cmd(cmd);
2224         transport_cmd_check_stop_to_fabric(cmd);
2225         return;
2226
2227 queue_full:
2228         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2229                 " data_direction: %d\n", cmd, cmd->data_direction);
2230
2231         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2232 }
2233
2234 void target_free_sgl(struct scatterlist *sgl, int nents)
2235 {
2236         struct scatterlist *sg;
2237         int count;
2238
2239         for_each_sg(sgl, sg, nents, count)
2240                 __free_page(sg_page(sg));
2241
2242         kfree(sgl);
2243 }
2244 EXPORT_SYMBOL(target_free_sgl);
2245
2246 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2247 {
2248         /*
2249          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2250          * emulation, and free + reset pointers if necessary..
2251          */
2252         if (!cmd->t_data_sg_orig)
2253                 return;
2254
2255         kfree(cmd->t_data_sg);
2256         cmd->t_data_sg = cmd->t_data_sg_orig;
2257         cmd->t_data_sg_orig = NULL;
2258         cmd->t_data_nents = cmd->t_data_nents_orig;
2259         cmd->t_data_nents_orig = 0;
2260 }
2261
2262 static inline void transport_free_pages(struct se_cmd *cmd)
2263 {
2264         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2265                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2266                 cmd->t_prot_sg = NULL;
2267                 cmd->t_prot_nents = 0;
2268         }
2269
2270         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2271                 /*
2272                  * Release special case READ buffer payload required for
2273                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2274                  */
2275                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2276                         target_free_sgl(cmd->t_bidi_data_sg,
2277                                            cmd->t_bidi_data_nents);
2278                         cmd->t_bidi_data_sg = NULL;
2279                         cmd->t_bidi_data_nents = 0;
2280                 }
2281                 transport_reset_sgl_orig(cmd);
2282                 return;
2283         }
2284         transport_reset_sgl_orig(cmd);
2285
2286         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2287         cmd->t_data_sg = NULL;
2288         cmd->t_data_nents = 0;
2289
2290         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2291         cmd->t_bidi_data_sg = NULL;
2292         cmd->t_bidi_data_nents = 0;
2293 }
2294
2295 /**
2296  * transport_put_cmd - release a reference to a command
2297  * @cmd:       command to release
2298  *
2299  * This routine releases our reference to the command and frees it if possible.
2300  */
2301 static int transport_put_cmd(struct se_cmd *cmd)
2302 {
2303         BUG_ON(!cmd->se_tfo);
2304         /*
2305          * If this cmd has been setup with target_get_sess_cmd(), drop
2306          * the kref and call ->release_cmd() in kref callback.
2307          */
2308         return target_put_sess_cmd(cmd);
2309 }
2310
2311 void *transport_kmap_data_sg(struct se_cmd *cmd)
2312 {
2313         struct scatterlist *sg = cmd->t_data_sg;
2314         struct page **pages;
2315         int i;
2316
2317         /*
2318          * We need to take into account a possible offset here for fabrics like
2319          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2320          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2321          */
2322         if (!cmd->t_data_nents)
2323                 return NULL;
2324
2325         BUG_ON(!sg);
2326         if (cmd->t_data_nents == 1)
2327                 return kmap(sg_page(sg)) + sg->offset;
2328
2329         /* >1 page. use vmap */
2330         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2331         if (!pages)
2332                 return NULL;
2333
2334         /* convert sg[] to pages[] */
2335         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2336                 pages[i] = sg_page(sg);
2337         }
2338
2339         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2340         kfree(pages);
2341         if (!cmd->t_data_vmap)
2342                 return NULL;
2343
2344         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2345 }
2346 EXPORT_SYMBOL(transport_kmap_data_sg);
2347
2348 void transport_kunmap_data_sg(struct se_cmd *cmd)
2349 {
2350         if (!cmd->t_data_nents) {
2351                 return;
2352         } else if (cmd->t_data_nents == 1) {
2353                 kunmap(sg_page(cmd->t_data_sg));
2354                 return;
2355         }
2356
2357         vunmap(cmd->t_data_vmap);
2358         cmd->t_data_vmap = NULL;
2359 }
2360 EXPORT_SYMBOL(transport_kunmap_data_sg);
2361
2362 int
2363 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2364                  bool zero_page, bool chainable)
2365 {
2366         struct scatterlist *sg;
2367         struct page *page;
2368         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2369         unsigned int nalloc, nent;
2370         int i = 0;
2371
2372         nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2373         if (chainable)
2374                 nalloc++;
2375         sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2376         if (!sg)
2377                 return -ENOMEM;
2378
2379         sg_init_table(sg, nalloc);
2380
2381         while (length) {
2382                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2383                 page = alloc_page(GFP_KERNEL | zero_flag);
2384                 if (!page)
2385                         goto out;
2386
2387                 sg_set_page(&sg[i], page, page_len, 0);
2388                 length -= page_len;
2389                 i++;
2390         }
2391         *sgl = sg;
2392         *nents = nent;
2393         return 0;
2394
2395 out:
2396         while (i > 0) {
2397                 i--;
2398                 __free_page(sg_page(&sg[i]));
2399         }
2400         kfree(sg);
2401         return -ENOMEM;
2402 }
2403 EXPORT_SYMBOL(target_alloc_sgl);
2404
2405 /*
2406  * Allocate any required resources to execute the command.  For writes we
2407  * might not have the payload yet, so notify the fabric via a call to
2408  * ->write_pending instead. Otherwise place it on the execution queue.
2409  */
2410 sense_reason_t
2411 transport_generic_new_cmd(struct se_cmd *cmd)
2412 {
2413         unsigned long flags;
2414         int ret = 0;
2415         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2416
2417         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2418             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2419                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2420                                        cmd->prot_length, true, false);
2421                 if (ret < 0)
2422                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2423         }
2424
2425         /*
2426          * Determine is the TCM fabric module has already allocated physical
2427          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2428          * beforehand.
2429          */
2430         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2431             cmd->data_length) {
2432
2433                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2434                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2435                         u32 bidi_length;
2436
2437                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2438                                 bidi_length = cmd->t_task_nolb *
2439                                               cmd->se_dev->dev_attrib.block_size;
2440                         else
2441                                 bidi_length = cmd->data_length;
2442
2443                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2444                                                &cmd->t_bidi_data_nents,
2445                                                bidi_length, zero_flag, false);
2446                         if (ret < 0)
2447                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2448                 }
2449
2450                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2451                                        cmd->data_length, zero_flag, false);
2452                 if (ret < 0)
2453                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2454         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2455                     cmd->data_length) {
2456                 /*
2457                  * Special case for COMPARE_AND_WRITE with fabrics
2458                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2459                  */
2460                 u32 caw_length = cmd->t_task_nolb *
2461                                  cmd->se_dev->dev_attrib.block_size;
2462
2463                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2464                                        &cmd->t_bidi_data_nents,
2465                                        caw_length, zero_flag, false);
2466                 if (ret < 0)
2467                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2468         }
2469         /*
2470          * If this command is not a write we can execute it right here,
2471          * for write buffers we need to notify the fabric driver first
2472          * and let it call back once the write buffers are ready.
2473          */
2474         target_add_to_state_list(cmd);
2475         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2476                 target_execute_cmd(cmd);
2477                 return 0;
2478         }
2479
2480         spin_lock_irqsave(&cmd->t_state_lock, flags);
2481         cmd->t_state = TRANSPORT_WRITE_PENDING;
2482         /*
2483          * Determine if frontend context caller is requesting the stopping of
2484          * this command for frontend exceptions.
2485          */
2486         if (cmd->transport_state & CMD_T_STOP) {
2487                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2488                          __func__, __LINE__, cmd->tag);
2489
2490                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2491
2492                 complete_all(&cmd->t_transport_stop_comp);
2493                 return 0;
2494         }
2495         cmd->transport_state &= ~CMD_T_ACTIVE;
2496         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2497
2498         ret = cmd->se_tfo->write_pending(cmd);
2499         if (ret)
2500                 goto queue_full;
2501
2502         return 0;
2503
2504 queue_full:
2505         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2506         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2507         return 0;
2508 }
2509 EXPORT_SYMBOL(transport_generic_new_cmd);
2510
2511 static void transport_write_pending_qf(struct se_cmd *cmd)
2512 {
2513         int ret;
2514
2515         ret = cmd->se_tfo->write_pending(cmd);
2516         if (ret) {
2517                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2518                          cmd);
2519                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2520         }
2521 }
2522
2523 static bool
2524 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2525                            unsigned long *flags);
2526
2527 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2528 {
2529         unsigned long flags;
2530
2531         spin_lock_irqsave(&cmd->t_state_lock, flags);
2532         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2533         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2534 }
2535
2536 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2537 {
2538         int ret = 0;
2539         bool aborted = false, tas = false;
2540
2541         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2542                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2543                         target_wait_free_cmd(cmd, &aborted, &tas);
2544
2545                 if (!aborted || tas)
2546                         ret = transport_put_cmd(cmd);
2547         } else {
2548                 if (wait_for_tasks)
2549                         target_wait_free_cmd(cmd, &aborted, &tas);
2550                 /*
2551                  * Handle WRITE failure case where transport_generic_new_cmd()
2552                  * has already added se_cmd to state_list, but fabric has
2553                  * failed command before I/O submission.
2554                  */
2555                 if (cmd->state_active)
2556                         target_remove_from_state_list(cmd);
2557
2558                 if (cmd->se_lun)
2559                         transport_lun_remove_cmd(cmd);
2560
2561                 if (!aborted || tas)
2562                         ret = transport_put_cmd(cmd);
2563         }
2564         /*
2565          * If the task has been internally aborted due to TMR ABORT_TASK
2566          * or LUN_RESET, target_core_tmr.c is responsible for performing
2567          * the remaining calls to target_put_sess_cmd(), and not the
2568          * callers of this function.
2569          */
2570         if (aborted) {
2571                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2572                 wait_for_completion(&cmd->cmd_wait_comp);
2573                 cmd->se_tfo->release_cmd(cmd);
2574                 ret = 1;
2575         }
2576         return ret;
2577 }
2578 EXPORT_SYMBOL(transport_generic_free_cmd);
2579
2580 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2581  * @se_cmd:     command descriptor to add
2582  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2583  */
2584 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2585 {
2586         struct se_session *se_sess = se_cmd->se_sess;
2587         unsigned long flags;
2588         int ret = 0;
2589
2590         /*
2591          * Add a second kref if the fabric caller is expecting to handle
2592          * fabric acknowledgement that requires two target_put_sess_cmd()
2593          * invocations before se_cmd descriptor release.
2594          */
2595         if (ack_kref) {
2596                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2597                         return -EINVAL;
2598
2599                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2600         }
2601
2602         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2603         if (se_sess->sess_tearing_down) {
2604                 ret = -ESHUTDOWN;
2605                 goto out;
2606         }
2607         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2608 out:
2609         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2610
2611         if (ret && ack_kref)
2612                 target_put_sess_cmd(se_cmd);
2613
2614         return ret;
2615 }
2616 EXPORT_SYMBOL(target_get_sess_cmd);
2617
2618 static void target_free_cmd_mem(struct se_cmd *cmd)
2619 {
2620         transport_free_pages(cmd);
2621
2622         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2623                 core_tmr_release_req(cmd->se_tmr_req);
2624         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2625                 kfree(cmd->t_task_cdb);
2626 }
2627
2628 static void target_release_cmd_kref(struct kref *kref)
2629 {
2630         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2631         struct se_session *se_sess = se_cmd->se_sess;
2632         unsigned long flags;
2633         bool fabric_stop;
2634
2635         if (se_sess) {
2636                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2637
2638                 spin_lock(&se_cmd->t_state_lock);
2639                 fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2640                               (se_cmd->transport_state & CMD_T_ABORTED);
2641                 spin_unlock(&se_cmd->t_state_lock);
2642
2643                 if (se_cmd->cmd_wait_set || fabric_stop) {
2644                         list_del_init(&se_cmd->se_cmd_list);
2645                         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2646                         target_free_cmd_mem(se_cmd);
2647                         complete(&se_cmd->cmd_wait_comp);
2648                         return;
2649                 }
2650                 list_del_init(&se_cmd->se_cmd_list);
2651                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2652         }
2653
2654         target_free_cmd_mem(se_cmd);
2655         se_cmd->se_tfo->release_cmd(se_cmd);
2656 }
2657
2658 /**
2659  * target_put_sess_cmd - decrease the command reference count
2660  * @se_cmd:     command to drop a reference from
2661  *
2662  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2663  * refcount to drop to zero. Returns zero otherwise.
2664  */
2665 int target_put_sess_cmd(struct se_cmd *se_cmd)
2666 {
2667         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2668 }
2669 EXPORT_SYMBOL(target_put_sess_cmd);
2670
2671 /* target_sess_cmd_list_set_waiting - Flag all commands in
2672  *         sess_cmd_list to complete cmd_wait_comp.  Set
2673  *         sess_tearing_down so no more commands are queued.
2674  * @se_sess:    session to flag
2675  */
2676 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2677 {
2678         struct se_cmd *se_cmd, *tmp_cmd;
2679         unsigned long flags;
2680         int rc;
2681
2682         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2683         if (se_sess->sess_tearing_down) {
2684                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2685                 return;
2686         }
2687         se_sess->sess_tearing_down = 1;
2688         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2689
2690         list_for_each_entry_safe(se_cmd, tmp_cmd,
2691                                  &se_sess->sess_wait_list, se_cmd_list) {
2692                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2693                 if (rc) {
2694                         se_cmd->cmd_wait_set = 1;
2695                         spin_lock(&se_cmd->t_state_lock);
2696                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2697                         spin_unlock(&se_cmd->t_state_lock);
2698                 } else
2699                         list_del_init(&se_cmd->se_cmd_list);
2700         }
2701
2702         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2703 }
2704 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2705
2706 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2707  * @se_sess:    session to wait for active I/O
2708  */
2709 void target_wait_for_sess_cmds(struct se_session *se_sess)
2710 {
2711         struct se_cmd *se_cmd, *tmp_cmd;
2712         unsigned long flags;
2713         bool tas;
2714
2715         list_for_each_entry_safe(se_cmd, tmp_cmd,
2716                                 &se_sess->sess_wait_list, se_cmd_list) {
2717                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2718                         " %d\n", se_cmd, se_cmd->t_state,
2719                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2720
2721                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2722                 tas = (se_cmd->transport_state & CMD_T_TAS);
2723                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2724
2725                 if (!target_put_sess_cmd(se_cmd)) {
2726                         if (tas)
2727                                 target_put_sess_cmd(se_cmd);
2728                 }
2729
2730                 wait_for_completion(&se_cmd->cmd_wait_comp);
2731                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2732                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2733                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2734
2735                 se_cmd->se_tfo->release_cmd(se_cmd);
2736         }
2737
2738         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2739         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2740         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2741
2742 }
2743 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2744
2745 static void target_lun_confirm(struct percpu_ref *ref)
2746 {
2747         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2748
2749         complete(&lun->lun_ref_comp);
2750 }
2751
2752 void transport_clear_lun_ref(struct se_lun *lun)
2753 {
2754         /*
2755          * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2756          * the initial reference and schedule confirm kill to be
2757          * executed after one full RCU grace period has completed.
2758          */
2759         percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2760         /*
2761          * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2762          * to call target_lun_confirm after lun->lun_ref has been marked
2763          * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2764          * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2765          * fails for all new incoming I/O.
2766          */
2767         wait_for_completion(&lun->lun_ref_comp);
2768         /*
2769          * The second completion waits for percpu_ref_put_many() to
2770          * invoke ->release() after lun->lun_ref has switched to
2771          * atomic_t mode, and lun->lun_ref.count has reached zero.
2772          *
2773          * At this point all target-core lun->lun_ref references have
2774          * been dropped via transport_lun_remove_cmd(), and it's safe
2775          * to proceed with the remaining LUN shutdown.
2776          */
2777         wait_for_completion(&lun->lun_shutdown_comp);
2778 }
2779
2780 static bool
2781 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2782                            bool *aborted, bool *tas, unsigned long *flags)
2783         __releases(&cmd->t_state_lock)
2784         __acquires(&cmd->t_state_lock)
2785 {
2786
2787         assert_spin_locked(&cmd->t_state_lock);
2788         WARN_ON_ONCE(!irqs_disabled());
2789
2790         if (fabric_stop)
2791                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2792
2793         if (cmd->transport_state & CMD_T_ABORTED)
2794                 *aborted = true;
2795
2796         if (cmd->transport_state & CMD_T_TAS)
2797                 *tas = true;
2798
2799         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2800             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2801                 return false;
2802
2803         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2804             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2805                 return false;
2806
2807         if (!(cmd->transport_state & CMD_T_ACTIVE))
2808                 return false;
2809
2810         if (fabric_stop && *aborted)
2811                 return false;
2812
2813         cmd->transport_state |= CMD_T_STOP;
2814
2815         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2816                  " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2817                  cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2818
2819         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2820
2821         wait_for_completion(&cmd->t_transport_stop_comp);
2822
2823         spin_lock_irqsave(&cmd->t_state_lock, *flags);
2824         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2825
2826         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2827                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2828
2829         return true;
2830 }
2831
2832 /**
2833  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
2834  * @cmd: command to wait on
2835  */
2836 bool transport_wait_for_tasks(struct se_cmd *cmd)
2837 {
2838         unsigned long flags;
2839         bool ret, aborted = false, tas = false;
2840
2841         spin_lock_irqsave(&cmd->t_state_lock, flags);
2842         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2843         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2844
2845         return ret;
2846 }
2847 EXPORT_SYMBOL(transport_wait_for_tasks);
2848
2849 struct sense_info {
2850         u8 key;
2851         u8 asc;
2852         u8 ascq;
2853         bool add_sector_info;
2854 };
2855
2856 static const struct sense_info sense_info_table[] = {
2857         [TCM_NO_SENSE] = {
2858                 .key = NOT_READY
2859         },
2860         [TCM_NON_EXISTENT_LUN] = {
2861                 .key = ILLEGAL_REQUEST,
2862                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2863         },
2864         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
2865                 .key = ILLEGAL_REQUEST,
2866                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2867         },
2868         [TCM_SECTOR_COUNT_TOO_MANY] = {
2869                 .key = ILLEGAL_REQUEST,
2870                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2871         },
2872         [TCM_UNKNOWN_MODE_PAGE] = {
2873                 .key = ILLEGAL_REQUEST,
2874                 .asc = 0x24, /* INVALID FIELD IN CDB */
2875         },
2876         [TCM_CHECK_CONDITION_ABORT_CMD] = {
2877                 .key = ABORTED_COMMAND,
2878                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2879                 .ascq = 0x03,
2880         },
2881         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
2882                 .key = ABORTED_COMMAND,
2883                 .asc = 0x0c, /* WRITE ERROR */
2884                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2885         },
2886         [TCM_INVALID_CDB_FIELD] = {
2887                 .key = ILLEGAL_REQUEST,
2888                 .asc = 0x24, /* INVALID FIELD IN CDB */
2889         },
2890         [TCM_INVALID_PARAMETER_LIST] = {
2891                 .key = ILLEGAL_REQUEST,
2892                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2893         },
2894         [TCM_TOO_MANY_TARGET_DESCS] = {
2895                 .key = ILLEGAL_REQUEST,
2896                 .asc = 0x26,
2897                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
2898         },
2899         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
2900                 .key = ILLEGAL_REQUEST,
2901                 .asc = 0x26,
2902                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
2903         },
2904         [TCM_TOO_MANY_SEGMENT_DESCS] = {
2905                 .key = ILLEGAL_REQUEST,
2906                 .asc = 0x26,
2907                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
2908         },
2909         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
2910                 .key = ILLEGAL_REQUEST,
2911                 .asc = 0x26,
2912                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
2913         },
2914         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2915                 .key = ILLEGAL_REQUEST,
2916                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2917         },
2918         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2919                 .key = ILLEGAL_REQUEST,
2920                 .asc = 0x0c, /* WRITE ERROR */
2921                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2922         },
2923         [TCM_SERVICE_CRC_ERROR] = {
2924                 .key = ABORTED_COMMAND,
2925                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2926                 .ascq = 0x05, /* N/A */
2927         },
2928         [TCM_SNACK_REJECTED] = {
2929                 .key = ABORTED_COMMAND,
2930                 .asc = 0x11, /* READ ERROR */
2931                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2932         },
2933         [TCM_WRITE_PROTECTED] = {
2934                 .key = DATA_PROTECT,
2935                 .asc = 0x27, /* WRITE PROTECTED */
2936         },
2937         [TCM_ADDRESS_OUT_OF_RANGE] = {
2938                 .key = ILLEGAL_REQUEST,
2939                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2940         },
2941         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2942                 .key = UNIT_ATTENTION,
2943         },
2944         [TCM_CHECK_CONDITION_NOT_READY] = {
2945                 .key = NOT_READY,
2946         },
2947         [TCM_MISCOMPARE_VERIFY] = {
2948                 .key = MISCOMPARE,
2949                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2950                 .ascq = 0x00,
2951         },
2952         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2953                 .key = ABORTED_COMMAND,
2954                 .asc = 0x10,
2955                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2956                 .add_sector_info = true,
2957         },
2958         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2959                 .key = ABORTED_COMMAND,
2960                 .asc = 0x10,
2961                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2962                 .add_sector_info = true,
2963         },
2964         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2965                 .key = ABORTED_COMMAND,
2966                 .asc = 0x10,
2967                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2968                 .add_sector_info = true,
2969         },
2970         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
2971                 .key = COPY_ABORTED,
2972                 .asc = 0x0d,
2973                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
2974
2975         },
2976         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2977                 /*
2978                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2979                  * Solaris initiators.  Returning NOT READY instead means the
2980                  * operations will be retried a finite number of times and we
2981                  * can survive intermittent errors.
2982                  */
2983                 .key = NOT_READY,
2984                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2985         },
2986 };
2987
2988 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2989 {
2990         const struct sense_info *si;
2991         u8 *buffer = cmd->sense_buffer;
2992         int r = (__force int)reason;
2993         u8 asc, ascq;
2994         bool desc_format = target_sense_desc_format(cmd->se_dev);
2995
2996         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2997                 si = &sense_info_table[r];
2998         else
2999                 si = &sense_info_table[(__force int)
3000                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3001
3002         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3003                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
3004                 WARN_ON_ONCE(asc == 0);
3005         } else if (si->asc == 0) {
3006                 WARN_ON_ONCE(cmd->scsi_asc == 0);
3007                 asc = cmd->scsi_asc;
3008                 ascq = cmd->scsi_ascq;
3009         } else {
3010                 asc = si->asc;
3011                 ascq = si->ascq;
3012         }
3013
3014         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
3015         if (si->add_sector_info)
3016                 return scsi_set_sense_information(buffer,
3017                                                   cmd->scsi_sense_length,
3018                                                   cmd->bad_sector);
3019
3020         return 0;
3021 }
3022
3023 int
3024 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3025                 sense_reason_t reason, int from_transport)
3026 {
3027         unsigned long flags;
3028
3029         spin_lock_irqsave(&cmd->t_state_lock, flags);
3030         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3031                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3032                 return 0;
3033         }
3034         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3035         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3036
3037         if (!from_transport) {
3038                 int rc;
3039
3040                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3041                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3042                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3043                 rc = translate_sense_reason(cmd, reason);
3044                 if (rc)
3045                         return rc;
3046         }
3047
3048         trace_target_cmd_complete(cmd);
3049         return cmd->se_tfo->queue_status(cmd);
3050 }
3051 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3052
3053 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3054         __releases(&cmd->t_state_lock)
3055         __acquires(&cmd->t_state_lock)
3056 {
3057         int ret;
3058
3059         assert_spin_locked(&cmd->t_state_lock);
3060         WARN_ON_ONCE(!irqs_disabled());
3061
3062         if (!(cmd->transport_state & CMD_T_ABORTED))
3063                 return 0;
3064         /*
3065          * If cmd has been aborted but either no status is to be sent or it has
3066          * already been sent, just return
3067          */
3068         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3069                 if (send_status)
3070                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3071                 return 1;
3072         }
3073
3074         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3075                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3076
3077         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3078         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3079         trace_target_cmd_complete(cmd);
3080
3081         spin_unlock_irq(&cmd->t_state_lock);
3082         ret = cmd->se_tfo->queue_status(cmd);
3083         if (ret)
3084                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3085         spin_lock_irq(&cmd->t_state_lock);
3086
3087         return 1;
3088 }
3089
3090 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3091 {
3092         int ret;
3093
3094         spin_lock_irq(&cmd->t_state_lock);
3095         ret = __transport_check_aborted_status(cmd, send_status);
3096         spin_unlock_irq(&cmd->t_state_lock);
3097
3098         return ret;
3099 }
3100 EXPORT_SYMBOL(transport_check_aborted_status);
3101
3102 void transport_send_task_abort(struct se_cmd *cmd)
3103 {
3104         unsigned long flags;
3105         int ret;
3106
3107         spin_lock_irqsave(&cmd->t_state_lock, flags);
3108         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3109                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3110                 return;
3111         }
3112         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3113
3114         /*
3115          * If there are still expected incoming fabric WRITEs, we wait
3116          * until until they have completed before sending a TASK_ABORTED
3117          * response.  This response with TASK_ABORTED status will be
3118          * queued back to fabric module by transport_check_aborted_status().
3119          */
3120         if (cmd->data_direction == DMA_TO_DEVICE) {
3121                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3122                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3123                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3124                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3125                                 goto send_abort;
3126                         }
3127                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3128                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3129                         return;
3130                 }
3131         }
3132 send_abort:
3133         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3134
3135         transport_lun_remove_cmd(cmd);
3136
3137         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3138                  cmd->t_task_cdb[0], cmd->tag);
3139
3140         trace_target_cmd_complete(cmd);
3141         ret = cmd->se_tfo->queue_status(cmd);
3142         if (ret)
3143                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3144 }
3145
3146 static void target_tmr_work(struct work_struct *work)
3147 {
3148         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3149         struct se_device *dev = cmd->se_dev;
3150         struct se_tmr_req *tmr = cmd->se_tmr_req;
3151         unsigned long flags;
3152         int ret;
3153
3154         spin_lock_irqsave(&cmd->t_state_lock, flags);
3155         if (cmd->transport_state & CMD_T_ABORTED) {
3156                 tmr->response = TMR_FUNCTION_REJECTED;
3157                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3158                 goto check_stop;
3159         }
3160         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3161
3162         switch (tmr->function) {
3163         case TMR_ABORT_TASK:
3164                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3165                 break;
3166         case TMR_ABORT_TASK_SET:
3167         case TMR_CLEAR_ACA:
3168         case TMR_CLEAR_TASK_SET:
3169                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3170                 break;
3171         case TMR_LUN_RESET:
3172                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3173                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3174                                          TMR_FUNCTION_REJECTED;
3175                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3176                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3177                                                cmd->orig_fe_lun, 0x29,
3178                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3179                 }
3180                 break;
3181         case TMR_TARGET_WARM_RESET:
3182                 tmr->response = TMR_FUNCTION_REJECTED;
3183                 break;
3184         case TMR_TARGET_COLD_RESET:
3185                 tmr->response = TMR_FUNCTION_REJECTED;
3186                 break;
3187         default:
3188                 pr_err("Uknown TMR function: 0x%02x.\n",
3189                                 tmr->function);
3190                 tmr->response = TMR_FUNCTION_REJECTED;
3191                 break;
3192         }
3193
3194         spin_lock_irqsave(&cmd->t_state_lock, flags);
3195         if (cmd->transport_state & CMD_T_ABORTED) {
3196                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3197                 goto check_stop;
3198         }
3199         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3200
3201         cmd->se_tfo->queue_tm_rsp(cmd);
3202
3203 check_stop:
3204         transport_cmd_check_stop_to_fabric(cmd);
3205 }
3206
3207 int transport_generic_handle_tmr(
3208         struct se_cmd *cmd)
3209 {
3210         unsigned long flags;
3211         bool aborted = false;
3212
3213         spin_lock_irqsave(&cmd->t_state_lock, flags);
3214         if (cmd->transport_state & CMD_T_ABORTED) {
3215                 aborted = true;
3216         } else {
3217                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3218                 cmd->transport_state |= CMD_T_ACTIVE;
3219         }
3220         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3221
3222         if (aborted) {
3223                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3224                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3225                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3226                 transport_cmd_check_stop_to_fabric(cmd);
3227                 return 0;
3228         }
3229
3230         INIT_WORK(&cmd->work, target_tmr_work);
3231         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3232         return 0;
3233 }
3234 EXPORT_SYMBOL(transport_generic_handle_tmr);
3235
3236 bool
3237 target_check_wce(struct se_device *dev)
3238 {
3239         bool wce = false;
3240
3241         if (dev->transport->get_write_cache)
3242                 wce = dev->transport->get_write_cache(dev);
3243         else if (dev->dev_attrib.emulate_write_cache > 0)
3244                 wce = true;
3245
3246         return wce;
3247 }
3248
3249 bool
3250 target_check_fua(struct se_device *dev)
3251 {
3252         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3253 }