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 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 655 {
 656         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 657
 658         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 659                 transport_lun_remove_cmd(cmd);
 660         /*
 661          * Allow the fabric driver to unmap any resources before
 662          * releasing the descriptor via TFO->release_cmd()
 663          */
 664         if (remove)
 665                 cmd->se_tfo->aborted_task(cmd);
 666
 667         if (transport_cmd_check_stop_to_fabric(cmd))
 668                 return;
 669         if (remove && ack_kref)
 670                 transport_put_cmd(cmd);
 671 }
 672
 673 static void target_complete_failure_work(struct work_struct *work)
 674 {
 675         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 676
 677         transport_generic_request_failure(cmd,
 678                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 679 }
 680
 681 /*
 682  * Used when asking transport to copy Sense Data from the underlying
 683  * Linux/SCSI struct scsi_cmnd
 684  */
 685 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 686 {
 687         struct se_device *dev = cmd->se_dev;
 688
 689         WARN_ON(!cmd->se_lun);
 690
 691         if (!dev)
 692                 return NULL;
 693
 694         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 695                 return NULL;
 696
 697         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 698
 699         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 700                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 701         return cmd->sense_buffer;
 702 }
 703
 704 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 705 {
 706         struct se_device *dev = cmd->se_dev;
 707         int success = scsi_status == GOOD;
 708         unsigned long flags;
 709
 710         cmd->scsi_status = scsi_status;
 711
 712
 713         spin_lock_irqsave(&cmd->t_state_lock, flags);
 714
 715         if (dev && dev->transport->transport_complete) {
 716                 dev->transport->transport_complete(cmd,
 717                                 cmd->t_data_sg,
 718                                 transport_get_sense_buffer(cmd));
 719                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 720                         success = 1;
 721         }
 722
 723         /*
 724          * Check for case where an explicit ABORT_TASK has been received
 725          * and transport_wait_for_tasks() will be waiting for completion..
 726          */
 727         if (cmd->transport_state & CMD_T_ABORTED ||
 728             cmd->transport_state & CMD_T_STOP) {
 729                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 730                 complete_all(&cmd->t_transport_stop_comp);
 731                 return;
 732         } else if (!success) {
 733                 INIT_WORK(&cmd->work, target_complete_failure_work);
 734         } else {
 735                 INIT_WORK(&cmd->work, target_complete_ok_work);
 736         }
 737
 738         cmd->t_state = TRANSPORT_COMPLETE;
 739         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 740         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 741
 742         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 743                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 744         else
 745                 queue_work(target_completion_wq, &cmd->work);
 746 }
 747 EXPORT_SYMBOL(target_complete_cmd);
 748
 749 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 750 {
 751         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 752                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 753                         cmd->residual_count += cmd->data_length - length;
 754                 } else {
 755                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 756                         cmd->residual_count = cmd->data_length - length;
 757                 }
 758
 759                 cmd->data_length = length;
 760         }
 761
 762         target_complete_cmd(cmd, scsi_status);
 763 }
 764 EXPORT_SYMBOL(target_complete_cmd_with_length);
 765
 766 static void target_add_to_state_list(struct se_cmd *cmd)
 767 {
 768         struct se_device *dev = cmd->se_dev;
 769         unsigned long flags;
 770
 771         spin_lock_irqsave(&dev->execute_task_lock, flags);
 772         if (!cmd->state_active) {
 773                 list_add_tail(&cmd->state_list, &dev->state_list);
 774                 cmd->state_active = true;
 775         }
 776         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 777 }
 778
 779 /*
 780  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 781  */
 782 static void transport_write_pending_qf(struct se_cmd *cmd);
 783 static void transport_complete_qf(struct se_cmd *cmd);
 784
 785 void target_qf_do_work(struct work_struct *work)
 786 {
 787         struct se_device *dev = container_of(work, struct se_device,
 788                                         qf_work_queue);
 789         LIST_HEAD(qf_cmd_list);
 790         struct se_cmd *cmd, *cmd_tmp;
 791
 792         spin_lock_irq(&dev->qf_cmd_lock);
 793         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 794         spin_unlock_irq(&dev->qf_cmd_lock);
 795
 796         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 797                 list_del(&cmd->se_qf_node);
 798                 atomic_dec_mb(&dev->dev_qf_count);
 799
 800                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 801                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 802                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 803                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 804                         : "UNKNOWN");
 805
 806                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 807                         transport_write_pending_qf(cmd);
 808                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 809                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 810                         transport_complete_qf(cmd);
 811         }
 812 }
 813
 814 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 815 {
 816         switch (cmd->data_direction) {
 817         case DMA_NONE:
 818                 return "NONE";
 819         case DMA_FROM_DEVICE:
 820                 return "READ";
 821         case DMA_TO_DEVICE:
 822                 return "WRITE";
 823         case DMA_BIDIRECTIONAL:
 824                 return "BIDI";
 825         default:
 826                 break;
 827         }
 828
 829         return "UNKNOWN";
 830 }
 831
 832 void transport_dump_dev_state(
 833         struct se_device *dev,
 834         char *b,
 835         int *bl)
 836 {
 837         *bl += sprintf(b + *bl, "Status: ");
 838         if (dev->export_count)
 839                 *bl += sprintf(b + *bl, "ACTIVATED");
 840         else
 841                 *bl += sprintf(b + *bl, "DEACTIVATED");
 842
 843         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 844         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 845                 dev->dev_attrib.block_size,
 846                 dev->dev_attrib.hw_max_sectors);
 847         *bl += sprintf(b + *bl, "        ");
 848 }
 849
 850 void transport_dump_vpd_proto_id(
 851         struct t10_vpd *vpd,
 852         unsigned char *p_buf,
 853         int p_buf_len)
 854 {
 855         unsigned char buf[VPD_TMP_BUF_SIZE];
 856         int len;
 857
 858         memset(buf, 0, VPD_TMP_BUF_SIZE);
 859         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 860
 861         switch (vpd->protocol_identifier) {
 862         case 0x00:
 863                 sprintf(buf+len, "Fibre Channel\n");
 864                 break;
 865         case 0x10:
 866                 sprintf(buf+len, "Parallel SCSI\n");
 867                 break;
 868         case 0x20:
 869                 sprintf(buf+len, "SSA\n");
 870                 break;
 871         case 0x30:
 872                 sprintf(buf+len, "IEEE 1394\n");
 873                 break;
 874         case 0x40:
 875                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 876                                 " Protocol\n");
 877                 break;
 878         case 0x50:
 879                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 880                 break;
 881         case 0x60:
 882                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 883                 break;
 884         case 0x70:
 885                 sprintf(buf+len, "Automation/Drive Interface Transport"
 886                                 " Protocol\n");
 887                 break;
 888         case 0x80:
 889                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 890                 break;
 891         default:
 892                 sprintf(buf+len, "Unknown 0x%02x\n",
 893                                 vpd->protocol_identifier);
 894                 break;
 895         }
 896
 897         if (p_buf)
 898                 strncpy(p_buf, buf, p_buf_len);
 899         else
 900                 pr_debug("%s", buf);
 901 }
 902
 903 void
 904 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 905 {
 906         /*
 907          * Check if the Protocol Identifier Valid (PIV) bit is set..
 908          *
 909          * from spc3r23.pdf section 7.5.1
 910          */
 911          if (page_83[1] & 0x80) {
 912                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 913                 vpd->protocol_identifier_set = 1;
 914                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 915         }
 916 }
 917 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 918
 919 int transport_dump_vpd_assoc(
 920         struct t10_vpd *vpd,
 921         unsigned char *p_buf,
 922         int p_buf_len)
 923 {
 924         unsigned char buf[VPD_TMP_BUF_SIZE];
 925         int ret = 0;
 926         int len;
 927
 928         memset(buf, 0, VPD_TMP_BUF_SIZE);
 929         len = sprintf(buf, "T10 VPD Identifier Association: ");
 930
 931         switch (vpd->association) {
 932         case 0x00:
 933                 sprintf(buf+len, "addressed logical unit\n");
 934                 break;
 935         case 0x10:
 936                 sprintf(buf+len, "target port\n");
 937                 break;
 938         case 0x20:
 939                 sprintf(buf+len, "SCSI target device\n");
 940                 break;
 941         default:
 942                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 943                 ret = -EINVAL;
 944                 break;
 945         }
 946
 947         if (p_buf)
 948                 strncpy(p_buf, buf, p_buf_len);
 949         else
 950                 pr_debug("%s", buf);
 951
 952         return ret;
 953 }
 954
 955 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 956 {
 957         /*
 958          * The VPD identification association..
 959          *
 960          * from spc3r23.pdf Section 7.6.3.1 Table 297
 961          */
 962         vpd->association = (page_83[1] & 0x30);
 963         return transport_dump_vpd_assoc(vpd, NULL, 0);
 964 }
 965 EXPORT_SYMBOL(transport_set_vpd_assoc);
 966
 967 int transport_dump_vpd_ident_type(
 968         struct t10_vpd *vpd,
 969         unsigned char *p_buf,
 970         int p_buf_len)
 971 {
 972         unsigned char buf[VPD_TMP_BUF_SIZE];
 973         int ret = 0;
 974         int len;
 975
 976         memset(buf, 0, VPD_TMP_BUF_SIZE);
 977         len = sprintf(buf, "T10 VPD Identifier Type: ");
 978
 979         switch (vpd->device_identifier_type) {
 980         case 0x00:
 981                 sprintf(buf+len, "Vendor specific\n");
 982                 break;
 983         case 0x01:
 984                 sprintf(buf+len, "T10 Vendor ID based\n");
 985                 break;
 986         case 0x02:
 987                 sprintf(buf+len, "EUI-64 based\n");
 988                 break;
 989         case 0x03:
 990                 sprintf(buf+len, "NAA\n");
 991                 break;
 992         case 0x04:
 993                 sprintf(buf+len, "Relative target port identifier\n");
 994                 break;
 995         case 0x08:
 996                 sprintf(buf+len, "SCSI name string\n");
 997                 break;
 998         default:
 999                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1000                                 vpd->device_identifier_type);
1001                 ret = -EINVAL;
1002                 break;
1003         }
1004
1005         if (p_buf) {
1006                 if (p_buf_len < strlen(buf)+1)
1007                         return -EINVAL;
1008                 strncpy(p_buf, buf, p_buf_len);
1009         } else {
1010                 pr_debug("%s", buf);
1011         }
1012
1013         return ret;
1014 }
1015
1016 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1017 {
1018         /*
1019          * The VPD identifier type..
1020          *
1021          * from spc3r23.pdf Section 7.6.3.1 Table 298
1022          */
1023         vpd->device_identifier_type = (page_83[1] & 0x0f);
1024         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1025 }
1026 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1027
1028 int transport_dump_vpd_ident(
1029         struct t10_vpd *vpd,
1030         unsigned char *p_buf,
1031         int p_buf_len)
1032 {
1033         unsigned char buf[VPD_TMP_BUF_SIZE];
1034         int ret = 0;
1035
1036         memset(buf, 0, VPD_TMP_BUF_SIZE);
1037
1038         switch (vpd->device_identifier_code_set) {
1039         case 0x01: /* Binary */
1040                 snprintf(buf, sizeof(buf),
1041                         "T10 VPD Binary Device Identifier: %s\n",
1042                         &vpd->device_identifier[0]);
1043                 break;
1044         case 0x02: /* ASCII */
1045                 snprintf(buf, sizeof(buf),
1046                         "T10 VPD ASCII Device Identifier: %s\n",
1047                         &vpd->device_identifier[0]);
1048                 break;
1049         case 0x03: /* UTF-8 */
1050                 snprintf(buf, sizeof(buf),
1051                         "T10 VPD UTF-8 Device Identifier: %s\n",
1052                         &vpd->device_identifier[0]);
1053                 break;
1054         default:
1055                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1056                         " 0x%02x", vpd->device_identifier_code_set);
1057                 ret = -EINVAL;
1058                 break;
1059         }
1060
1061         if (p_buf)
1062                 strncpy(p_buf, buf, p_buf_len);
1063         else
1064                 pr_debug("%s", buf);
1065
1066         return ret;
1067 }
1068
1069 int
1070 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1071 {
1072         static const char hex_str[] = "0123456789abcdef";
1073         int j = 0, i = 4; /* offset to start of the identifier */
1074
1075         /*
1076          * The VPD Code Set (encoding)
1077          *
1078          * from spc3r23.pdf Section 7.6.3.1 Table 296
1079          */
1080         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1081         switch (vpd->device_identifier_code_set) {
1082         case 0x01: /* Binary */
1083                 vpd->device_identifier[j++] =
1084                                 hex_str[vpd->device_identifier_type];
1085                 while (i < (4 + page_83[3])) {
1086                         vpd->device_identifier[j++] =
1087                                 hex_str[(page_83[i] & 0xf0) >> 4];
1088                         vpd->device_identifier[j++] =
1089                                 hex_str[page_83[i] & 0x0f];
1090                         i++;
1091                 }
1092                 break;
1093         case 0x02: /* ASCII */
1094         case 0x03: /* UTF-8 */
1095                 while (i < (4 + page_83[3]))
1096                         vpd->device_identifier[j++] = page_83[i++];
1097                 break;
1098         default:
1099                 break;
1100         }
1101
1102         return transport_dump_vpd_ident(vpd, NULL, 0);
1103 }
1104 EXPORT_SYMBOL(transport_set_vpd_ident);
1105
1106 static sense_reason_t
1107 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1108                                unsigned int size)
1109 {
1110         u32 mtl;
1111
1112         if (!cmd->se_tfo->max_data_sg_nents)
1113                 return TCM_NO_SENSE;
1114         /*
1115          * Check if fabric enforced maximum SGL entries per I/O descriptor
1116          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1117          * residual_count and reduce original cmd->data_length to maximum
1118          * length based on single PAGE_SIZE entry scatter-lists.
1119          */
1120         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1121         if (cmd->data_length > mtl) {
1122                 /*
1123                  * If an existing CDB overflow is present, calculate new residual
1124                  * based on CDB size minus fabric maximum transfer length.
1125                  *
1126                  * If an existing CDB underflow is present, calculate new residual
1127                  * based on original cmd->data_length minus fabric maximum transfer
1128                  * length.
1129                  *
1130                  * Otherwise, set the underflow residual based on cmd->data_length
1131                  * minus fabric maximum transfer length.
1132                  */
1133                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1134                         cmd->residual_count = (size - mtl);
1135                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1136                         u32 orig_dl = size + cmd->residual_count;
1137                         cmd->residual_count = (orig_dl - mtl);
1138                 } else {
1139                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1140                         cmd->residual_count = (cmd->data_length - mtl);
1141                 }
1142                 cmd->data_length = mtl;
1143                 /*
1144                  * Reset sbc_check_prot() calculated protection payload
1145                  * length based upon the new smaller MTL.
1146                  */
1147                 if (cmd->prot_length) {
1148                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1149                         cmd->prot_length = dev->prot_length * sectors;
1150                 }
1151         }
1152         return TCM_NO_SENSE;
1153 }
1154
1155 sense_reason_t
1156 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1157 {
1158         struct se_device *dev = cmd->se_dev;
1159
1160         if (cmd->unknown_data_length) {
1161                 cmd->data_length = size;
1162         } else if (size != cmd->data_length) {
1163                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1164                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1165                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1166                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1167
1168                 if (cmd->data_direction == DMA_TO_DEVICE &&
1169                     cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1170                         pr_err("Rejecting underflow/overflow WRITE data\n");
1171                         return TCM_INVALID_CDB_FIELD;
1172                 }
1173                 /*
1174                  * Reject READ_* or WRITE_* with overflow/underflow for
1175                  * type SCF_SCSI_DATA_CDB.
1176                  */
1177                 if (dev->dev_attrib.block_size != 512)  {
1178                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1179                                 " CDB on non 512-byte sector setup subsystem"
1180                                 " plugin: %s\n", dev->transport->name);
1181                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1182                         return TCM_INVALID_CDB_FIELD;
1183                 }
1184                 /*
1185                  * For the overflow case keep the existing fabric provided
1186                  * ->data_length.  Otherwise for the underflow case, reset
1187                  * ->data_length to the smaller SCSI expected data transfer
1188                  * length.
1189                  */
1190                 if (size > cmd->data_length) {
1191                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1192                         cmd->residual_count = (size - cmd->data_length);
1193                 } else {
1194                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1195                         cmd->residual_count = (cmd->data_length - size);
1196                         cmd->data_length = size;
1197                 }
1198         }
1199
1200         return target_check_max_data_sg_nents(cmd, dev, size);
1201
1202 }
1203
1204 /*
1205  * Used by fabric modules containing a local struct se_cmd within their
1206  * fabric dependent per I/O descriptor.
1207  *
1208  * Preserves the value of @cmd->tag.
1209  */
1210 void transport_init_se_cmd(
1211         struct se_cmd *cmd,
1212         const struct target_core_fabric_ops *tfo,
1213         struct se_session *se_sess,
1214         u32 data_length,
1215         int data_direction,
1216         int task_attr,
1217         unsigned char *sense_buffer)
1218 {
1219         INIT_LIST_HEAD(&cmd->se_delayed_node);
1220         INIT_LIST_HEAD(&cmd->se_qf_node);
1221         INIT_LIST_HEAD(&cmd->se_cmd_list);
1222         INIT_LIST_HEAD(&cmd->state_list);
1223         init_completion(&cmd->t_transport_stop_comp);
1224         init_completion(&cmd->cmd_wait_comp);
1225         spin_lock_init(&cmd->t_state_lock);
1226         kref_init(&cmd->cmd_kref);
1227
1228         cmd->se_tfo = tfo;
1229         cmd->se_sess = se_sess;
1230         cmd->data_length = data_length;
1231         cmd->data_direction = data_direction;
1232         cmd->sam_task_attr = task_attr;
1233         cmd->sense_buffer = sense_buffer;
1234
1235         cmd->state_active = false;
1236 }
1237 EXPORT_SYMBOL(transport_init_se_cmd);
1238
1239 static sense_reason_t
1240 transport_check_alloc_task_attr(struct se_cmd *cmd)
1241 {
1242         struct se_device *dev = cmd->se_dev;
1243
1244         /*
1245          * Check if SAM Task Attribute emulation is enabled for this
1246          * struct se_device storage object
1247          */
1248         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1249                 return 0;
1250
1251         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1252                 pr_debug("SAM Task Attribute ACA"
1253                         " emulation is not supported\n");
1254                 return TCM_INVALID_CDB_FIELD;
1255         }
1256
1257         return 0;
1258 }
1259
1260 sense_reason_t
1261 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1262 {
1263         struct se_device *dev = cmd->se_dev;
1264         sense_reason_t ret;
1265
1266         /*
1267          * Ensure that the received CDB is less than the max (252 + 8) bytes
1268          * for VARIABLE_LENGTH_CMD
1269          */
1270         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1271                 pr_err("Received SCSI CDB with command_size: %d that"
1272                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1273                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1274                 return TCM_INVALID_CDB_FIELD;
1275         }
1276         /*
1277          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1278          * allocate the additional extended CDB buffer now..  Otherwise
1279          * setup the pointer from __t_task_cdb to t_task_cdb.
1280          */
1281         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1282                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1283                                                 GFP_KERNEL);
1284                 if (!cmd->t_task_cdb) {
1285                         pr_err("Unable to allocate cmd->t_task_cdb"
1286                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1287                                 scsi_command_size(cdb),
1288                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1289                         return TCM_OUT_OF_RESOURCES;
1290                 }
1291         } else
1292                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1293         /*
1294          * Copy the original CDB into cmd->
1295          */
1296         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1297
1298         trace_target_sequencer_start(cmd);
1299
1300         ret = dev->transport->parse_cdb(cmd);
1301         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1302                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1303                                     cmd->se_tfo->get_fabric_name(),
1304                                     cmd->se_sess->se_node_acl->initiatorname,
1305                                     cmd->t_task_cdb[0]);
1306         if (ret)
1307                 return ret;
1308
1309         ret = transport_check_alloc_task_attr(cmd);
1310         if (ret)
1311                 return ret;
1312
1313         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1314         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1315         return 0;
1316 }
1317 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1318
1319 /*
1320  * Used by fabric module frontends to queue tasks directly.
1321  * May only be used from process context.
1322  */
1323 int transport_handle_cdb_direct(
1324         struct se_cmd *cmd)
1325 {
1326         sense_reason_t ret;
1327
1328         if (!cmd->se_lun) {
1329                 dump_stack();
1330                 pr_err("cmd->se_lun is NULL\n");
1331                 return -EINVAL;
1332         }
1333         if (in_interrupt()) {
1334                 dump_stack();
1335                 pr_err("transport_generic_handle_cdb cannot be called"
1336                                 " from interrupt context\n");
1337                 return -EINVAL;
1338         }
1339         /*
1340          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1341          * outstanding descriptors are handled correctly during shutdown via
1342          * transport_wait_for_tasks()
1343          *
1344          * Also, we don't take cmd->t_state_lock here as we only expect
1345          * this to be called for initial descriptor submission.
1346          */
1347         cmd->t_state = TRANSPORT_NEW_CMD;
1348         cmd->transport_state |= CMD_T_ACTIVE;
1349
1350         /*
1351          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1352          * so follow TRANSPORT_NEW_CMD processing thread context usage
1353          * and call transport_generic_request_failure() if necessary..
1354          */
1355         ret = transport_generic_new_cmd(cmd);
1356         if (ret)
1357                 transport_generic_request_failure(cmd, ret);
1358         return 0;
1359 }
1360 EXPORT_SYMBOL(transport_handle_cdb_direct);
1361
1362 sense_reason_t
1363 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1364                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1365 {
1366         if (!sgl || !sgl_count)
1367                 return 0;
1368
1369         /*
1370          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1371          * scatterlists already have been set to follow what the fabric
1372          * passes for the original expected data transfer length.
1373          */
1374         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1375                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1376                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1377                 return TCM_INVALID_CDB_FIELD;
1378         }
1379
1380         cmd->t_data_sg = sgl;
1381         cmd->t_data_nents = sgl_count;
1382         cmd->t_bidi_data_sg = sgl_bidi;
1383         cmd->t_bidi_data_nents = sgl_bidi_count;
1384
1385         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1386         return 0;
1387 }
1388
1389 /*
1390  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1391  *                       se_cmd + use pre-allocated SGL memory.
1392  *
1393  * @se_cmd: command descriptor to submit
1394  * @se_sess: associated se_sess for endpoint
1395  * @cdb: pointer to SCSI CDB
1396  * @sense: pointer to SCSI sense buffer
1397  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1398  * @data_length: fabric expected data transfer length
1399  * @task_addr: SAM task attribute
1400  * @data_dir: DMA data direction
1401  * @flags: flags for command submission from target_sc_flags_tables
1402  * @sgl: struct scatterlist memory for unidirectional mapping
1403  * @sgl_count: scatterlist count for unidirectional mapping
1404  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1405  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1406  * @sgl_prot: struct scatterlist memory protection information
1407  * @sgl_prot_count: scatterlist count for protection information
1408  *
1409  * Task tags are supported if the caller has set @se_cmd->tag.
1410  *
1411  * Returns non zero to signal active I/O shutdown failure.  All other
1412  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1413  * but still return zero here.
1414  *
1415  * This may only be called from process context, and also currently
1416  * assumes internal allocation of fabric payload buffer by target-core.
1417  */
1418 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1419                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1420                 u32 data_length, int task_attr, int data_dir, int flags,
1421                 struct scatterlist *sgl, u32 sgl_count,
1422                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1423                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1424 {
1425         struct se_portal_group *se_tpg;
1426         sense_reason_t rc;
1427         int ret;
1428
1429         se_tpg = se_sess->se_tpg;
1430         BUG_ON(!se_tpg);
1431         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1432         BUG_ON(in_interrupt());
1433         /*
1434          * Initialize se_cmd for target operation.  From this point
1435          * exceptions are handled by sending exception status via
1436          * target_core_fabric_ops->queue_status() callback
1437          */
1438         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1439                                 data_length, data_dir, task_attr, sense);
1440
1441         if (flags & TARGET_SCF_USE_CPUID)
1442                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1443         else
1444                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1445
1446         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1447                 se_cmd->unknown_data_length = 1;
1448         /*
1449          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1450          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1451          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1452          * kref_put() to happen during fabric packet acknowledgement.
1453          */
1454         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1455         if (ret)
1456                 return ret;
1457         /*
1458          * Signal bidirectional data payloads to target-core
1459          */
1460         if (flags & TARGET_SCF_BIDI_OP)
1461                 se_cmd->se_cmd_flags |= SCF_BIDI;
1462         /*
1463          * Locate se_lun pointer and attach it to struct se_cmd
1464          */
1465         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1466         if (rc) {
1467                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1468                 target_put_sess_cmd(se_cmd);
1469                 return 0;
1470         }
1471
1472         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1473         if (rc != 0) {
1474                 transport_generic_request_failure(se_cmd, rc);
1475                 return 0;
1476         }
1477
1478         /*
1479          * Save pointers for SGLs containing protection information,
1480          * if present.
1481          */
1482         if (sgl_prot_count) {
1483                 se_cmd->t_prot_sg = sgl_prot;
1484                 se_cmd->t_prot_nents = sgl_prot_count;
1485                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1486         }
1487
1488         /*
1489          * When a non zero sgl_count has been passed perform SGL passthrough
1490          * mapping for pre-allocated fabric memory instead of having target
1491          * core perform an internal SGL allocation..
1492          */
1493         if (sgl_count != 0) {
1494                 BUG_ON(!sgl);
1495
1496                 /*
1497                  * A work-around for tcm_loop as some userspace code via
1498                  * scsi-generic do not memset their associated read buffers,
1499                  * so go ahead and do that here for type non-data CDBs.  Also
1500                  * note that this is currently guaranteed to be a single SGL
1501                  * for this case by target core in target_setup_cmd_from_cdb()
1502                  * -> transport_generic_cmd_sequencer().
1503                  */
1504                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1505                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1506                         unsigned char *buf = NULL;
1507
1508                         if (sgl)
1509                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1510
1511                         if (buf) {
1512                                 memset(buf, 0, sgl->length);
1513                                 kunmap(sg_page(sgl));
1514                         }
1515                 }
1516
1517                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1518                                 sgl_bidi, sgl_bidi_count);
1519                 if (rc != 0) {
1520                         transport_generic_request_failure(se_cmd, rc);
1521                         return 0;
1522                 }
1523         }
1524
1525         /*
1526          * Check if we need to delay processing because of ALUA
1527          * Active/NonOptimized primary access state..
1528          */
1529         core_alua_check_nonop_delay(se_cmd);
1530
1531         transport_handle_cdb_direct(se_cmd);
1532         return 0;
1533 }
1534 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1535
1536 /*
1537  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1538  *
1539  * @se_cmd: command descriptor to submit
1540  * @se_sess: associated se_sess for endpoint
1541  * @cdb: pointer to SCSI CDB
1542  * @sense: pointer to SCSI sense buffer
1543  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1544  * @data_length: fabric expected data transfer length
1545  * @task_addr: SAM task attribute
1546  * @data_dir: DMA data direction
1547  * @flags: flags for command submission from target_sc_flags_tables
1548  *
1549  * Task tags are supported if the caller has set @se_cmd->tag.
1550  *
1551  * Returns non zero to signal active I/O shutdown failure.  All other
1552  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1553  * but still return zero here.
1554  *
1555  * This may only be called from process context, and also currently
1556  * assumes internal allocation of fabric payload buffer by target-core.
1557  *
1558  * It also assumes interal target core SGL memory allocation.
1559  */
1560 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1561                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1562                 u32 data_length, int task_attr, int data_dir, int flags)
1563 {
1564         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1565                         unpacked_lun, data_length, task_attr, data_dir,
1566                         flags, NULL, 0, NULL, 0, NULL, 0);
1567 }
1568 EXPORT_SYMBOL(target_submit_cmd);
1569
1570 static void target_complete_tmr_failure(struct work_struct *work)
1571 {
1572         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1573
1574         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1575         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1576
1577         transport_cmd_check_stop_to_fabric(se_cmd);
1578 }
1579
1580 /**
1581  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1582  *                     for TMR CDBs
1583  *
1584  * @se_cmd: command descriptor to submit
1585  * @se_sess: associated se_sess for endpoint
1586  * @sense: pointer to SCSI sense buffer
1587  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1588  * @fabric_context: fabric context for TMR req
1589  * @tm_type: Type of TM request
1590  * @gfp: gfp type for caller
1591  * @tag: referenced task tag for TMR_ABORT_TASK
1592  * @flags: submit cmd flags
1593  *
1594  * Callable from all contexts.
1595  **/
1596
1597 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1598                 unsigned char *sense, u64 unpacked_lun,
1599                 void *fabric_tmr_ptr, unsigned char tm_type,
1600                 gfp_t gfp, u64 tag, int flags)
1601 {
1602         struct se_portal_group *se_tpg;
1603         int ret;
1604
1605         se_tpg = se_sess->se_tpg;
1606         BUG_ON(!se_tpg);
1607
1608         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1609                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1610         /*
1611          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1612          * allocation failure.
1613          */
1614         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1615         if (ret < 0)
1616                 return -ENOMEM;
1617
1618         if (tm_type == TMR_ABORT_TASK)
1619                 se_cmd->se_tmr_req->ref_task_tag = tag;
1620
1621         /* See target_submit_cmd for commentary */
1622         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1623         if (ret) {
1624                 core_tmr_release_req(se_cmd->se_tmr_req);
1625                 return ret;
1626         }
1627
1628         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1629         if (ret) {
1630                 /*
1631                  * For callback during failure handling, push this work off
1632                  * to process context with TMR_LUN_DOES_NOT_EXIST status.
1633                  */
1634                 INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1635                 schedule_work(&se_cmd->work);
1636                 return 0;
1637         }
1638         transport_generic_handle_tmr(se_cmd);
1639         return 0;
1640 }
1641 EXPORT_SYMBOL(target_submit_tmr);
1642
1643 /*
1644  * Handle SAM-esque emulation for generic transport request failures.
1645  */
1646 void transport_generic_request_failure(struct se_cmd *cmd,
1647                 sense_reason_t sense_reason)
1648 {
1649         int ret = 0, post_ret = 0;
1650
1651         if (transport_check_aborted_status(cmd, 1))
1652                 return;
1653
1654         pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1655                 " CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1656         pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1657                 cmd->se_tfo->get_cmd_state(cmd),
1658                 cmd->t_state, sense_reason);
1659         pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1660                 (cmd->transport_state & CMD_T_ACTIVE) != 0,
1661                 (cmd->transport_state & CMD_T_STOP) != 0,
1662                 (cmd->transport_state & CMD_T_SENT) != 0);
1663
1664         /*
1665          * For SAM Task Attribute emulation for failed struct se_cmd
1666          */
1667         transport_complete_task_attr(cmd);
1668         /*
1669          * Handle special case for COMPARE_AND_WRITE failure, where the
1670          * callback is expected to drop the per device ->caw_sem.
1671          */
1672         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1673              cmd->transport_complete_callback)
1674                 cmd->transport_complete_callback(cmd, false, &post_ret);
1675
1676         switch (sense_reason) {
1677         case TCM_NON_EXISTENT_LUN:
1678         case TCM_UNSUPPORTED_SCSI_OPCODE:
1679         case TCM_INVALID_CDB_FIELD:
1680         case TCM_INVALID_PARAMETER_LIST:
1681         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1682         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1683         case TCM_UNKNOWN_MODE_PAGE:
1684         case TCM_WRITE_PROTECTED:
1685         case TCM_ADDRESS_OUT_OF_RANGE:
1686         case TCM_CHECK_CONDITION_ABORT_CMD:
1687         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1688         case TCM_CHECK_CONDITION_NOT_READY:
1689         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1690         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1691         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1692         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1693         case TCM_TOO_MANY_TARGET_DESCS:
1694         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1695         case TCM_TOO_MANY_SEGMENT_DESCS:
1696         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1697                 break;
1698         case TCM_OUT_OF_RESOURCES:
1699                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1700                 break;
1701         case TCM_RESERVATION_CONFLICT:
1702                 /*
1703                  * No SENSE Data payload for this case, set SCSI Status
1704                  * and queue the response to $FABRIC_MOD.
1705                  *
1706                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1707                  */
1708                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1709                 /*
1710                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1711                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1712                  * CONFLICT STATUS.
1713                  *
1714                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1715                  */
1716                 if (cmd->se_sess &&
1717                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1718                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1719                                                cmd->orig_fe_lun, 0x2C,
1720                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1721                 }
1722                 trace_target_cmd_complete(cmd);
1723                 ret = cmd->se_tfo->queue_status(cmd);
1724                 if (ret)
1725                         goto queue_full;
1726                 goto check_stop;
1727         default:
1728                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1729                         cmd->t_task_cdb[0], sense_reason);
1730                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1731                 break;
1732         }
1733
1734         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1735         if (ret)
1736                 goto queue_full;
1737
1738 check_stop:
1739         transport_lun_remove_cmd(cmd);
1740         transport_cmd_check_stop_to_fabric(cmd);
1741         return;
1742
1743 queue_full:
1744         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1745 }
1746 EXPORT_SYMBOL(transport_generic_request_failure);
1747
1748 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1749 {
1750         sense_reason_t ret;
1751
1752         if (!cmd->execute_cmd) {
1753                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1754                 goto err;
1755         }
1756         if (do_checks) {
1757                 /*
1758                  * Check for an existing UNIT ATTENTION condition after
1759                  * target_handle_task_attr() has done SAM task attr
1760                  * checking, and possibly have already defered execution
1761                  * out to target_restart_delayed_cmds() context.
1762                  */
1763                 ret = target_scsi3_ua_check(cmd);
1764                 if (ret)
1765                         goto err;
1766
1767                 ret = target_alua_state_check(cmd);
1768                 if (ret)
1769                         goto err;
1770
1771                 ret = target_check_reservation(cmd);
1772                 if (ret) {
1773                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1774                         goto err;
1775                 }
1776         }
1777
1778         ret = cmd->execute_cmd(cmd);
1779         if (!ret)
1780                 return;
1781 err:
1782         spin_lock_irq(&cmd->t_state_lock);
1783         cmd->transport_state &= ~CMD_T_SENT;
1784         spin_unlock_irq(&cmd->t_state_lock);
1785
1786         transport_generic_request_failure(cmd, ret);
1787 }
1788
1789 static int target_write_prot_action(struct se_cmd *cmd)
1790 {
1791         u32 sectors;
1792         /*
1793          * Perform WRITE_INSERT of PI using software emulation when backend
1794          * device has PI enabled, if the transport has not already generated
1795          * PI using hardware WRITE_INSERT offload.
1796          */
1797         switch (cmd->prot_op) {
1798         case TARGET_PROT_DOUT_INSERT:
1799                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1800                         sbc_dif_generate(cmd);
1801                 break;
1802         case TARGET_PROT_DOUT_STRIP:
1803                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1804                         break;
1805
1806                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1807                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1808                                              sectors, 0, cmd->t_prot_sg, 0);
1809                 if (unlikely(cmd->pi_err)) {
1810                         spin_lock_irq(&cmd->t_state_lock);
1811                         cmd->transport_state &= ~CMD_T_SENT;
1812                         spin_unlock_irq(&cmd->t_state_lock);
1813                         transport_generic_request_failure(cmd, cmd->pi_err);
1814                         return -1;
1815                 }
1816                 break;
1817         default:
1818                 break;
1819         }
1820
1821         return 0;
1822 }
1823
1824 static bool target_handle_task_attr(struct se_cmd *cmd)
1825 {
1826         struct se_device *dev = cmd->se_dev;
1827
1828         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1829                 return false;
1830
1831         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1832
1833         /*
1834          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1835          * to allow the passed struct se_cmd list of tasks to the front of the list.
1836          */
1837         switch (cmd->sam_task_attr) {
1838         case TCM_HEAD_TAG:
1839                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1840                          cmd->t_task_cdb[0]);
1841                 return false;
1842         case TCM_ORDERED_TAG:
1843                 atomic_inc_mb(&dev->dev_ordered_sync);
1844
1845                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1846                          cmd->t_task_cdb[0]);
1847
1848                 /*
1849                  * Execute an ORDERED command if no other older commands
1850                  * exist that need to be completed first.
1851                  */
1852                 if (!atomic_read(&dev->simple_cmds))
1853                         return false;
1854                 break;
1855         default:
1856                 /*
1857                  * For SIMPLE and UNTAGGED Task Attribute commands
1858                  */
1859                 atomic_inc_mb(&dev->simple_cmds);
1860                 break;
1861         }
1862
1863         if (atomic_read(&dev->dev_ordered_sync) == 0)
1864                 return false;
1865
1866         spin_lock(&dev->delayed_cmd_lock);
1867         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1868         spin_unlock(&dev->delayed_cmd_lock);
1869
1870         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1871                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1872         return true;
1873 }
1874
1875 static int __transport_check_aborted_status(struct se_cmd *, int);
1876
1877 void target_execute_cmd(struct se_cmd *cmd)
1878 {
1879         /*
1880          * Determine if frontend context caller is requesting the stopping of
1881          * this command for frontend exceptions.
1882          *
1883          * If the received CDB has aleady been aborted stop processing it here.
1884          */
1885         spin_lock_irq(&cmd->t_state_lock);
1886         if (__transport_check_aborted_status(cmd, 1)) {
1887                 spin_unlock_irq(&cmd->t_state_lock);
1888                 return;
1889         }
1890         if (cmd->transport_state & CMD_T_STOP) {
1891                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1892                         __func__, __LINE__, cmd->tag);
1893
1894                 spin_unlock_irq(&cmd->t_state_lock);
1895                 complete_all(&cmd->t_transport_stop_comp);
1896                 return;
1897         }
1898
1899         cmd->t_state = TRANSPORT_PROCESSING;
1900         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
1901         spin_unlock_irq(&cmd->t_state_lock);
1902
1903         if (target_write_prot_action(cmd))
1904                 return;
1905
1906         if (target_handle_task_attr(cmd)) {
1907                 spin_lock_irq(&cmd->t_state_lock);
1908                 cmd->transport_state &= ~CMD_T_SENT;
1909                 spin_unlock_irq(&cmd->t_state_lock);
1910                 return;
1911         }
1912
1913         __target_execute_cmd(cmd, true);
1914 }
1915 EXPORT_SYMBOL(target_execute_cmd);
1916
1917 /*
1918  * Process all commands up to the last received ORDERED task attribute which
1919  * requires another blocking boundary
1920  */
1921 static void target_restart_delayed_cmds(struct se_device *dev)
1922 {
1923         for (;;) {
1924                 struct se_cmd *cmd;
1925
1926                 spin_lock(&dev->delayed_cmd_lock);
1927                 if (list_empty(&dev->delayed_cmd_list)) {
1928                         spin_unlock(&dev->delayed_cmd_lock);
1929                         break;
1930                 }
1931
1932                 cmd = list_entry(dev->delayed_cmd_list.next,
1933                                  struct se_cmd, se_delayed_node);
1934                 list_del(&cmd->se_delayed_node);
1935                 spin_unlock(&dev->delayed_cmd_lock);
1936
1937                 __target_execute_cmd(cmd, true);
1938
1939                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1940                         break;
1941         }
1942 }
1943
1944 /*
1945  * Called from I/O completion to determine which dormant/delayed
1946  * and ordered cmds need to have their tasks added to the execution queue.
1947  */
1948 static void transport_complete_task_attr(struct se_cmd *cmd)
1949 {
1950         struct se_device *dev = cmd->se_dev;
1951
1952         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1953                 return;
1954
1955         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
1956                 goto restart;
1957
1958         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1959                 atomic_dec_mb(&dev->simple_cmds);
1960                 dev->dev_cur_ordered_id++;
1961         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1962                 dev->dev_cur_ordered_id++;
1963                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1964                          dev->dev_cur_ordered_id);
1965         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1966                 atomic_dec_mb(&dev->dev_ordered_sync);
1967
1968                 dev->dev_cur_ordered_id++;
1969                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1970                          dev->dev_cur_ordered_id);
1971         }
1972 restart:
1973         target_restart_delayed_cmds(dev);
1974 }
1975
1976 static void transport_complete_qf(struct se_cmd *cmd)
1977 {
1978         int ret = 0;
1979
1980         transport_complete_task_attr(cmd);
1981         /*
1982          * If a fabric driver ->write_pending() or ->queue_data_in() callback
1983          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
1984          * the same callbacks should not be retried.  Return CHECK_CONDITION
1985          * if a scsi_status is not already set.
1986          *
1987          * If a fabric driver ->queue_status() has returned non zero, always
1988          * keep retrying no matter what..
1989          */
1990         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
1991                 if (cmd->scsi_status)
1992                         goto queue_status;
1993
1994                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
1995                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
1996                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
1997                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
1998                 goto queue_status;
1999         }
2000
2001         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2002                 goto queue_status;
2003
2004         switch (cmd->data_direction) {
2005         case DMA_FROM_DEVICE:
2006                 if (cmd->scsi_status)
2007                         goto queue_status;
2008
2009                 trace_target_cmd_complete(cmd);
2010                 ret = cmd->se_tfo->queue_data_in(cmd);
2011                 break;
2012         case DMA_TO_DEVICE:
2013                 if (cmd->se_cmd_flags & SCF_BIDI) {
2014                         ret = cmd->se_tfo->queue_data_in(cmd);
2015                         break;
2016                 }
2017                 /* Fall through for DMA_TO_DEVICE */
2018         case DMA_NONE:
2019 queue_status:
2020                 trace_target_cmd_complete(cmd);
2021                 ret = cmd->se_tfo->queue_status(cmd);
2022                 break;
2023         default:
2024                 break;
2025         }
2026
2027         if (ret < 0) {
2028                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2029                 return;
2030         }
2031         transport_lun_remove_cmd(cmd);
2032         transport_cmd_check_stop_to_fabric(cmd);
2033 }
2034
2035 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2036                                         int err, bool write_pending)
2037 {
2038         /*
2039          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2040          * ->queue_data_in() callbacks from new process context.
2041          *
2042          * Otherwise for other errors, transport_complete_qf() will send
2043          * CHECK_CONDITION via ->queue_status() instead of attempting to
2044          * retry associated fabric driver data-transfer callbacks.
2045          */
2046         if (err == -EAGAIN || err == -ENOMEM) {
2047                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2048                                                  TRANSPORT_COMPLETE_QF_OK;
2049         } else {
2050                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2051                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2052         }
2053
2054         spin_lock_irq(&dev->qf_cmd_lock);
2055         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2056         atomic_inc_mb(&dev->dev_qf_count);
2057         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2058
2059         schedule_work(&cmd->se_dev->qf_work_queue);
2060 }
2061
2062 static bool target_read_prot_action(struct se_cmd *cmd)
2063 {
2064         switch (cmd->prot_op) {
2065         case TARGET_PROT_DIN_STRIP:
2066                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2067                         u32 sectors = cmd->data_length >>
2068                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2069
2070                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2071                                                      sectors, 0, cmd->t_prot_sg,
2072                                                      0);
2073                         if (cmd->pi_err)
2074                                 return true;
2075                 }
2076                 break;
2077         case TARGET_PROT_DIN_INSERT:
2078                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2079                         break;
2080
2081                 sbc_dif_generate(cmd);
2082                 break;
2083         default:
2084                 break;
2085         }
2086
2087         return false;
2088 }
2089
2090 static void target_complete_ok_work(struct work_struct *work)
2091 {
2092         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2093         int ret;
2094
2095         /*
2096          * Check if we need to move delayed/dormant tasks from cmds on the
2097          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2098          * Attribute.
2099          */
2100         transport_complete_task_attr(cmd);
2101
2102         /*
2103          * Check to schedule QUEUE_FULL work, or execute an existing
2104          * cmd->transport_qf_callback()
2105          */
2106         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2107                 schedule_work(&cmd->se_dev->qf_work_queue);
2108
2109         /*
2110          * Check if we need to send a sense buffer from
2111          * the struct se_cmd in question.
2112          */
2113         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2114                 WARN_ON(!cmd->scsi_status);
2115                 ret = transport_send_check_condition_and_sense(
2116                                         cmd, 0, 1);
2117                 if (ret)
2118                         goto queue_full;
2119
2120                 transport_lun_remove_cmd(cmd);
2121                 transport_cmd_check_stop_to_fabric(cmd);
2122                 return;
2123         }
2124         /*
2125          * Check for a callback, used by amongst other things
2126          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2127          */
2128         if (cmd->transport_complete_callback) {
2129                 sense_reason_t rc;
2130                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2131                 bool zero_dl = !(cmd->data_length);
2132                 int post_ret = 0;
2133
2134                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2135                 if (!rc && !post_ret) {
2136                         if (caw && zero_dl)
2137                                 goto queue_rsp;
2138
2139                         return;
2140                 } else if (rc) {
2141                         ret = transport_send_check_condition_and_sense(cmd,
2142                                                 rc, 0);
2143                         if (ret)
2144                                 goto queue_full;
2145
2146                         transport_lun_remove_cmd(cmd);
2147                         transport_cmd_check_stop_to_fabric(cmd);
2148                         return;
2149                 }
2150         }
2151
2152 queue_rsp:
2153         switch (cmd->data_direction) {
2154         case DMA_FROM_DEVICE:
2155                 if (cmd->scsi_status)
2156                         goto queue_status;
2157
2158                 atomic_long_add(cmd->data_length,
2159                                 &cmd->se_lun->lun_stats.tx_data_octets);
2160                 /*
2161                  * Perform READ_STRIP of PI using software emulation when
2162                  * backend had PI enabled, if the transport will not be
2163                  * performing hardware READ_STRIP offload.
2164                  */
2165                 if (target_read_prot_action(cmd)) {
2166                         ret = transport_send_check_condition_and_sense(cmd,
2167                                                 cmd->pi_err, 0);
2168                         if (ret)
2169                                 goto queue_full;
2170
2171                         transport_lun_remove_cmd(cmd);
2172                         transport_cmd_check_stop_to_fabric(cmd);
2173                         return;
2174                 }
2175
2176                 trace_target_cmd_complete(cmd);
2177                 ret = cmd->se_tfo->queue_data_in(cmd);
2178                 if (ret)
2179                         goto queue_full;
2180                 break;
2181         case DMA_TO_DEVICE:
2182                 atomic_long_add(cmd->data_length,
2183                                 &cmd->se_lun->lun_stats.rx_data_octets);
2184                 /*
2185                  * Check if we need to send READ payload for BIDI-COMMAND
2186                  */
2187                 if (cmd->se_cmd_flags & SCF_BIDI) {
2188                         atomic_long_add(cmd->data_length,
2189                                         &cmd->se_lun->lun_stats.tx_data_octets);
2190                         ret = cmd->se_tfo->queue_data_in(cmd);
2191                         if (ret)
2192                                 goto queue_full;
2193                         break;
2194                 }
2195                 /* Fall through for DMA_TO_DEVICE */
2196         case DMA_NONE:
2197 queue_status:
2198                 trace_target_cmd_complete(cmd);
2199                 ret = cmd->se_tfo->queue_status(cmd);
2200                 if (ret)
2201                         goto queue_full;
2202                 break;
2203         default:
2204                 break;
2205         }
2206
2207         transport_lun_remove_cmd(cmd);
2208         transport_cmd_check_stop_to_fabric(cmd);
2209         return;
2210
2211 queue_full:
2212         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2213                 " data_direction: %d\n", cmd, cmd->data_direction);
2214
2215         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2216 }
2217
2218 void target_free_sgl(struct scatterlist *sgl, int nents)
2219 {
2220         struct scatterlist *sg;
2221         int count;
2222
2223         for_each_sg(sgl, sg, nents, count)
2224                 __free_page(sg_page(sg));
2225
2226         kfree(sgl);
2227 }
2228 EXPORT_SYMBOL(target_free_sgl);
2229
2230 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2231 {
2232         /*
2233          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2234          * emulation, and free + reset pointers if necessary..
2235          */
2236         if (!cmd->t_data_sg_orig)
2237                 return;
2238
2239         kfree(cmd->t_data_sg);
2240         cmd->t_data_sg = cmd->t_data_sg_orig;
2241         cmd->t_data_sg_orig = NULL;
2242         cmd->t_data_nents = cmd->t_data_nents_orig;
2243         cmd->t_data_nents_orig = 0;
2244 }
2245
2246 static inline void transport_free_pages(struct se_cmd *cmd)
2247 {
2248         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2249                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2250                 cmd->t_prot_sg = NULL;
2251                 cmd->t_prot_nents = 0;
2252         }
2253
2254         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2255                 /*
2256                  * Release special case READ buffer payload required for
2257                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2258                  */
2259                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2260                         target_free_sgl(cmd->t_bidi_data_sg,
2261                                            cmd->t_bidi_data_nents);
2262                         cmd->t_bidi_data_sg = NULL;
2263                         cmd->t_bidi_data_nents = 0;
2264                 }
2265                 transport_reset_sgl_orig(cmd);
2266                 return;
2267         }
2268         transport_reset_sgl_orig(cmd);
2269
2270         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2271         cmd->t_data_sg = NULL;
2272         cmd->t_data_nents = 0;
2273
2274         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2275         cmd->t_bidi_data_sg = NULL;
2276         cmd->t_bidi_data_nents = 0;
2277 }
2278
2279 /**
2280  * transport_put_cmd - release a reference to a command
2281  * @cmd:       command to release
2282  *
2283  * This routine releases our reference to the command and frees it if possible.
2284  */
2285 static int transport_put_cmd(struct se_cmd *cmd)
2286 {
2287         BUG_ON(!cmd->se_tfo);
2288         /*
2289          * If this cmd has been setup with target_get_sess_cmd(), drop
2290          * the kref and call ->release_cmd() in kref callback.
2291          */
2292         return target_put_sess_cmd(cmd);
2293 }
2294
2295 void *transport_kmap_data_sg(struct se_cmd *cmd)
2296 {
2297         struct scatterlist *sg = cmd->t_data_sg;
2298         struct page **pages;
2299         int i;
2300
2301         /*
2302          * We need to take into account a possible offset here for fabrics like
2303          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2304          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2305          */
2306         if (!cmd->t_data_nents)
2307                 return NULL;
2308
2309         BUG_ON(!sg);
2310         if (cmd->t_data_nents == 1)
2311                 return kmap(sg_page(sg)) + sg->offset;
2312
2313         /* >1 page. use vmap */
2314         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2315         if (!pages)
2316                 return NULL;
2317
2318         /* convert sg[] to pages[] */
2319         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2320                 pages[i] = sg_page(sg);
2321         }
2322
2323         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2324         kfree(pages);
2325         if (!cmd->t_data_vmap)
2326                 return NULL;
2327
2328         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2329 }
2330 EXPORT_SYMBOL(transport_kmap_data_sg);
2331
2332 void transport_kunmap_data_sg(struct se_cmd *cmd)
2333 {
2334         if (!cmd->t_data_nents) {
2335                 return;
2336         } else if (cmd->t_data_nents == 1) {
2337                 kunmap(sg_page(cmd->t_data_sg));
2338                 return;
2339         }
2340
2341         vunmap(cmd->t_data_vmap);
2342         cmd->t_data_vmap = NULL;
2343 }
2344 EXPORT_SYMBOL(transport_kunmap_data_sg);
2345
2346 int
2347 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2348                  bool zero_page, bool chainable)
2349 {
2350         struct scatterlist *sg;
2351         struct page *page;
2352         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2353         unsigned int nalloc, nent;
2354         int i = 0;
2355
2356         nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2357         if (chainable)
2358                 nalloc++;
2359         sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2360         if (!sg)
2361                 return -ENOMEM;
2362
2363         sg_init_table(sg, nalloc);
2364
2365         while (length) {
2366                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2367                 page = alloc_page(GFP_KERNEL | zero_flag);
2368                 if (!page)
2369                         goto out;
2370
2371                 sg_set_page(&sg[i], page, page_len, 0);
2372                 length -= page_len;
2373                 i++;
2374         }
2375         *sgl = sg;
2376         *nents = nent;
2377         return 0;
2378
2379 out:
2380         while (i > 0) {
2381                 i--;
2382                 __free_page(sg_page(&sg[i]));
2383         }
2384         kfree(sg);
2385         return -ENOMEM;
2386 }
2387 EXPORT_SYMBOL(target_alloc_sgl);
2388
2389 /*
2390  * Allocate any required resources to execute the command.  For writes we
2391  * might not have the payload yet, so notify the fabric via a call to
2392  * ->write_pending instead. Otherwise place it on the execution queue.
2393  */
2394 sense_reason_t
2395 transport_generic_new_cmd(struct se_cmd *cmd)
2396 {
2397         unsigned long flags;
2398         int ret = 0;
2399         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2400
2401         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2402             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2403                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2404                                        cmd->prot_length, true, false);
2405                 if (ret < 0)
2406                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2407         }
2408
2409         /*
2410          * Determine is the TCM fabric module has already allocated physical
2411          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2412          * beforehand.
2413          */
2414         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2415             cmd->data_length) {
2416
2417                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2418                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2419                         u32 bidi_length;
2420
2421                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2422                                 bidi_length = cmd->t_task_nolb *
2423                                               cmd->se_dev->dev_attrib.block_size;
2424                         else
2425                                 bidi_length = cmd->data_length;
2426
2427                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2428                                                &cmd->t_bidi_data_nents,
2429                                                bidi_length, zero_flag, false);
2430                         if (ret < 0)
2431                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2432                 }
2433
2434                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2435                                        cmd->data_length, zero_flag, false);
2436                 if (ret < 0)
2437                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2438         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2439                     cmd->data_length) {
2440                 /*
2441                  * Special case for COMPARE_AND_WRITE with fabrics
2442                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2443                  */
2444                 u32 caw_length = cmd->t_task_nolb *
2445                                  cmd->se_dev->dev_attrib.block_size;
2446
2447                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2448                                        &cmd->t_bidi_data_nents,
2449                                        caw_length, zero_flag, false);
2450                 if (ret < 0)
2451                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2452         }
2453         /*
2454          * If this command is not a write we can execute it right here,
2455          * for write buffers we need to notify the fabric driver first
2456          * and let it call back once the write buffers are ready.
2457          */
2458         target_add_to_state_list(cmd);
2459         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2460                 target_execute_cmd(cmd);
2461                 return 0;
2462         }
2463
2464         spin_lock_irqsave(&cmd->t_state_lock, flags);
2465         cmd->t_state = TRANSPORT_WRITE_PENDING;
2466         /*
2467          * Determine if frontend context caller is requesting the stopping of
2468          * this command for frontend exceptions.
2469          */
2470         if (cmd->transport_state & CMD_T_STOP) {
2471                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2472                          __func__, __LINE__, cmd->tag);
2473
2474                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2475
2476                 complete_all(&cmd->t_transport_stop_comp);
2477                 return 0;
2478         }
2479         cmd->transport_state &= ~CMD_T_ACTIVE;
2480         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2481
2482         ret = cmd->se_tfo->write_pending(cmd);
2483         if (ret)
2484                 goto queue_full;
2485
2486         return 0;
2487
2488 queue_full:
2489         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2490         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2491         return 0;
2492 }
2493 EXPORT_SYMBOL(transport_generic_new_cmd);
2494
2495 static void transport_write_pending_qf(struct se_cmd *cmd)
2496 {
2497         int ret;
2498
2499         ret = cmd->se_tfo->write_pending(cmd);
2500         if (ret) {
2501                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2502                          cmd);
2503                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2504         }
2505 }
2506
2507 static bool
2508 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2509                            unsigned long *flags);
2510
2511 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2512 {
2513         unsigned long flags;
2514
2515         spin_lock_irqsave(&cmd->t_state_lock, flags);
2516         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2517         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2518 }
2519
2520 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2521 {
2522         int ret = 0;
2523         bool aborted = false, tas = false;
2524
2525         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2526                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2527                         target_wait_free_cmd(cmd, &aborted, &tas);
2528
2529                 if (!aborted || tas)
2530                         ret = transport_put_cmd(cmd);
2531         } else {
2532                 if (wait_for_tasks)
2533                         target_wait_free_cmd(cmd, &aborted, &tas);
2534                 /*
2535                  * Handle WRITE failure case where transport_generic_new_cmd()
2536                  * has already added se_cmd to state_list, but fabric has
2537                  * failed command before I/O submission.
2538                  */
2539                 if (cmd->state_active)
2540                         target_remove_from_state_list(cmd);
2541
2542                 if (cmd->se_lun)
2543                         transport_lun_remove_cmd(cmd);
2544
2545                 if (!aborted || tas)
2546                         ret = transport_put_cmd(cmd);
2547         }
2548         /*
2549          * If the task has been internally aborted due to TMR ABORT_TASK
2550          * or LUN_RESET, target_core_tmr.c is responsible for performing
2551          * the remaining calls to target_put_sess_cmd(), and not the
2552          * callers of this function.
2553          */
2554         if (aborted) {
2555                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2556                 wait_for_completion(&cmd->cmd_wait_comp);
2557                 cmd->se_tfo->release_cmd(cmd);
2558                 ret = 1;
2559         }
2560         return ret;
2561 }
2562 EXPORT_SYMBOL(transport_generic_free_cmd);
2563
2564 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2565  * @se_cmd:     command descriptor to add
2566  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2567  */
2568 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2569 {
2570         struct se_session *se_sess = se_cmd->se_sess;
2571         unsigned long flags;
2572         int ret = 0;
2573
2574         /*
2575          * Add a second kref if the fabric caller is expecting to handle
2576          * fabric acknowledgement that requires two target_put_sess_cmd()
2577          * invocations before se_cmd descriptor release.
2578          */
2579         if (ack_kref) {
2580                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2581                         return -EINVAL;
2582
2583                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2584         }
2585
2586         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2587         if (se_sess->sess_tearing_down) {
2588                 ret = -ESHUTDOWN;
2589                 goto out;
2590         }
2591         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2592 out:
2593         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2594
2595         if (ret && ack_kref)
2596                 target_put_sess_cmd(se_cmd);
2597
2598         return ret;
2599 }
2600 EXPORT_SYMBOL(target_get_sess_cmd);
2601
2602 static void target_free_cmd_mem(struct se_cmd *cmd)
2603 {
2604         transport_free_pages(cmd);
2605
2606         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2607                 core_tmr_release_req(cmd->se_tmr_req);
2608         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2609                 kfree(cmd->t_task_cdb);
2610 }
2611
2612 static void target_release_cmd_kref(struct kref *kref)
2613 {
2614         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2615         struct se_session *se_sess = se_cmd->se_sess;
2616         unsigned long flags;
2617         bool fabric_stop;
2618
2619         if (se_sess) {
2620                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2621
2622                 spin_lock(&se_cmd->t_state_lock);
2623                 fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2624                               (se_cmd->transport_state & CMD_T_ABORTED);
2625                 spin_unlock(&se_cmd->t_state_lock);
2626
2627                 if (se_cmd->cmd_wait_set || fabric_stop) {
2628                         list_del_init(&se_cmd->se_cmd_list);
2629                         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2630                         target_free_cmd_mem(se_cmd);
2631                         complete(&se_cmd->cmd_wait_comp);
2632                         return;
2633                 }
2634                 list_del_init(&se_cmd->se_cmd_list);
2635                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2636         }
2637
2638         target_free_cmd_mem(se_cmd);
2639         se_cmd->se_tfo->release_cmd(se_cmd);
2640 }
2641
2642 /**
2643  * target_put_sess_cmd - decrease the command reference count
2644  * @se_cmd:     command to drop a reference from
2645  *
2646  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2647  * refcount to drop to zero. Returns zero otherwise.
2648  */
2649 int target_put_sess_cmd(struct se_cmd *se_cmd)
2650 {
2651         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2652 }
2653 EXPORT_SYMBOL(target_put_sess_cmd);
2654
2655 /* target_sess_cmd_list_set_waiting - Flag all commands in
2656  *         sess_cmd_list to complete cmd_wait_comp.  Set
2657  *         sess_tearing_down so no more commands are queued.
2658  * @se_sess:    session to flag
2659  */
2660 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2661 {
2662         struct se_cmd *se_cmd, *tmp_cmd;
2663         unsigned long flags;
2664         int rc;
2665
2666         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2667         if (se_sess->sess_tearing_down) {
2668                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2669                 return;
2670         }
2671         se_sess->sess_tearing_down = 1;
2672         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2673
2674         list_for_each_entry_safe(se_cmd, tmp_cmd,
2675                                  &se_sess->sess_wait_list, se_cmd_list) {
2676                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2677                 if (rc) {
2678                         se_cmd->cmd_wait_set = 1;
2679                         spin_lock(&se_cmd->t_state_lock);
2680                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2681                         spin_unlock(&se_cmd->t_state_lock);
2682                 } else
2683                         list_del_init(&se_cmd->se_cmd_list);
2684         }
2685
2686         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2687 }
2688 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2689
2690 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2691  * @se_sess:    session to wait for active I/O
2692  */
2693 void target_wait_for_sess_cmds(struct se_session *se_sess)
2694 {
2695         struct se_cmd *se_cmd, *tmp_cmd;
2696         unsigned long flags;
2697         bool tas;
2698
2699         list_for_each_entry_safe(se_cmd, tmp_cmd,
2700                                 &se_sess->sess_wait_list, se_cmd_list) {
2701                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2702                         " %d\n", se_cmd, se_cmd->t_state,
2703                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2704
2705                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2706                 tas = (se_cmd->transport_state & CMD_T_TAS);
2707                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2708
2709                 if (!target_put_sess_cmd(se_cmd)) {
2710                         if (tas)
2711                                 target_put_sess_cmd(se_cmd);
2712                 }
2713
2714                 wait_for_completion(&se_cmd->cmd_wait_comp);
2715                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2716                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2717                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2718
2719                 se_cmd->se_tfo->release_cmd(se_cmd);
2720         }
2721
2722         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2723         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2724         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2725
2726 }
2727 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2728
2729 static void target_lun_confirm(struct percpu_ref *ref)
2730 {
2731         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2732
2733         complete(&lun->lun_ref_comp);
2734 }
2735
2736 void transport_clear_lun_ref(struct se_lun *lun)
2737 {
2738         /*
2739          * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2740          * the initial reference and schedule confirm kill to be
2741          * executed after one full RCU grace period has completed.
2742          */
2743         percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2744         /*
2745          * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2746          * to call target_lun_confirm after lun->lun_ref has been marked
2747          * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2748          * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2749          * fails for all new incoming I/O.
2750          */
2751         wait_for_completion(&lun->lun_ref_comp);
2752         /*
2753          * The second completion waits for percpu_ref_put_many() to
2754          * invoke ->release() after lun->lun_ref has switched to
2755          * atomic_t mode, and lun->lun_ref.count has reached zero.
2756          *
2757          * At this point all target-core lun->lun_ref references have
2758          * been dropped via transport_lun_remove_cmd(), and it's safe
2759          * to proceed with the remaining LUN shutdown.
2760          */
2761         wait_for_completion(&lun->lun_shutdown_comp);
2762 }
2763
2764 static bool
2765 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2766                            bool *aborted, bool *tas, unsigned long *flags)
2767         __releases(&cmd->t_state_lock)
2768         __acquires(&cmd->t_state_lock)
2769 {
2770
2771         assert_spin_locked(&cmd->t_state_lock);
2772         WARN_ON_ONCE(!irqs_disabled());
2773
2774         if (fabric_stop)
2775                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2776
2777         if (cmd->transport_state & CMD_T_ABORTED)
2778                 *aborted = true;
2779
2780         if (cmd->transport_state & CMD_T_TAS)
2781                 *tas = true;
2782
2783         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2784             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2785                 return false;
2786
2787         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2788             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2789                 return false;
2790
2791         if (!(cmd->transport_state & CMD_T_ACTIVE))
2792                 return false;
2793
2794         if (fabric_stop && *aborted)
2795                 return false;
2796
2797         cmd->transport_state |= CMD_T_STOP;
2798
2799         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2800                  " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2801                  cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2802
2803         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2804
2805         wait_for_completion(&cmd->t_transport_stop_comp);
2806
2807         spin_lock_irqsave(&cmd->t_state_lock, *flags);
2808         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2809
2810         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2811                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2812
2813         return true;
2814 }
2815
2816 /**
2817  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
2818  * @cmd: command to wait on
2819  */
2820 bool transport_wait_for_tasks(struct se_cmd *cmd)
2821 {
2822         unsigned long flags;
2823         bool ret, aborted = false, tas = false;
2824
2825         spin_lock_irqsave(&cmd->t_state_lock, flags);
2826         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2827         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2828
2829         return ret;
2830 }
2831 EXPORT_SYMBOL(transport_wait_for_tasks);
2832
2833 struct sense_info {
2834         u8 key;
2835         u8 asc;
2836         u8 ascq;
2837         bool add_sector_info;
2838 };
2839
2840 static const struct sense_info sense_info_table[] = {
2841         [TCM_NO_SENSE] = {
2842                 .key = NOT_READY
2843         },
2844         [TCM_NON_EXISTENT_LUN] = {
2845                 .key = ILLEGAL_REQUEST,
2846                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2847         },
2848         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
2849                 .key = ILLEGAL_REQUEST,
2850                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2851         },
2852         [TCM_SECTOR_COUNT_TOO_MANY] = {
2853                 .key = ILLEGAL_REQUEST,
2854                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2855         },
2856         [TCM_UNKNOWN_MODE_PAGE] = {
2857                 .key = ILLEGAL_REQUEST,
2858                 .asc = 0x24, /* INVALID FIELD IN CDB */
2859         },
2860         [TCM_CHECK_CONDITION_ABORT_CMD] = {
2861                 .key = ABORTED_COMMAND,
2862                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2863                 .ascq = 0x03,
2864         },
2865         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
2866                 .key = ABORTED_COMMAND,
2867                 .asc = 0x0c, /* WRITE ERROR */
2868                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2869         },
2870         [TCM_INVALID_CDB_FIELD] = {
2871                 .key = ILLEGAL_REQUEST,
2872                 .asc = 0x24, /* INVALID FIELD IN CDB */
2873         },
2874         [TCM_INVALID_PARAMETER_LIST] = {
2875                 .key = ILLEGAL_REQUEST,
2876                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2877         },
2878         [TCM_TOO_MANY_TARGET_DESCS] = {
2879                 .key = ILLEGAL_REQUEST,
2880                 .asc = 0x26,
2881                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
2882         },
2883         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
2884                 .key = ILLEGAL_REQUEST,
2885                 .asc = 0x26,
2886                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
2887         },
2888         [TCM_TOO_MANY_SEGMENT_DESCS] = {
2889                 .key = ILLEGAL_REQUEST,
2890                 .asc = 0x26,
2891                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
2892         },
2893         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
2894                 .key = ILLEGAL_REQUEST,
2895                 .asc = 0x26,
2896                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
2897         },
2898         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2899                 .key = ILLEGAL_REQUEST,
2900                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2901         },
2902         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2903                 .key = ILLEGAL_REQUEST,
2904                 .asc = 0x0c, /* WRITE ERROR */
2905                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2906         },
2907         [TCM_SERVICE_CRC_ERROR] = {
2908                 .key = ABORTED_COMMAND,
2909                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2910                 .ascq = 0x05, /* N/A */
2911         },
2912         [TCM_SNACK_REJECTED] = {
2913                 .key = ABORTED_COMMAND,
2914                 .asc = 0x11, /* READ ERROR */
2915                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2916         },
2917         [TCM_WRITE_PROTECTED] = {
2918                 .key = DATA_PROTECT,
2919                 .asc = 0x27, /* WRITE PROTECTED */
2920         },
2921         [TCM_ADDRESS_OUT_OF_RANGE] = {
2922                 .key = ILLEGAL_REQUEST,
2923                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2924         },
2925         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2926                 .key = UNIT_ATTENTION,
2927         },
2928         [TCM_CHECK_CONDITION_NOT_READY] = {
2929                 .key = NOT_READY,
2930         },
2931         [TCM_MISCOMPARE_VERIFY] = {
2932                 .key = MISCOMPARE,
2933                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2934                 .ascq = 0x00,
2935         },
2936         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2937                 .key = ABORTED_COMMAND,
2938                 .asc = 0x10,
2939                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2940                 .add_sector_info = true,
2941         },
2942         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2943                 .key = ABORTED_COMMAND,
2944                 .asc = 0x10,
2945                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2946                 .add_sector_info = true,
2947         },
2948         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2949                 .key = ABORTED_COMMAND,
2950                 .asc = 0x10,
2951                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2952                 .add_sector_info = true,
2953         },
2954         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
2955                 .key = COPY_ABORTED,
2956                 .asc = 0x0d,
2957                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
2958
2959         },
2960         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2961                 /*
2962                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2963                  * Solaris initiators.  Returning NOT READY instead means the
2964                  * operations will be retried a finite number of times and we
2965                  * can survive intermittent errors.
2966                  */
2967                 .key = NOT_READY,
2968                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2969         },
2970 };
2971
2972 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2973 {
2974         const struct sense_info *si;
2975         u8 *buffer = cmd->sense_buffer;
2976         int r = (__force int)reason;
2977         u8 asc, ascq;
2978         bool desc_format = target_sense_desc_format(cmd->se_dev);
2979
2980         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2981                 si = &sense_info_table[r];
2982         else
2983                 si = &sense_info_table[(__force int)
2984                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2985
2986         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2987                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2988                 WARN_ON_ONCE(asc == 0);
2989         } else if (si->asc == 0) {
2990                 WARN_ON_ONCE(cmd->scsi_asc == 0);
2991                 asc = cmd->scsi_asc;
2992                 ascq = cmd->scsi_ascq;
2993         } else {
2994                 asc = si->asc;
2995                 ascq = si->ascq;
2996         }
2997
2998         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2999         if (si->add_sector_info)
3000                 return scsi_set_sense_information(buffer,
3001                                                   cmd->scsi_sense_length,
3002                                                   cmd->bad_sector);
3003
3004         return 0;
3005 }
3006
3007 int
3008 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3009                 sense_reason_t reason, int from_transport)
3010 {
3011         unsigned long flags;
3012
3013         spin_lock_irqsave(&cmd->t_state_lock, flags);
3014         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3015                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3016                 return 0;
3017         }
3018         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3019         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3020
3021         if (!from_transport) {
3022                 int rc;
3023
3024                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3025                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3026                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3027                 rc = translate_sense_reason(cmd, reason);
3028                 if (rc)
3029                         return rc;
3030         }
3031
3032         trace_target_cmd_complete(cmd);
3033         return cmd->se_tfo->queue_status(cmd);
3034 }
3035 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3036
3037 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3038         __releases(&cmd->t_state_lock)
3039         __acquires(&cmd->t_state_lock)
3040 {
3041         int ret;
3042
3043         assert_spin_locked(&cmd->t_state_lock);
3044         WARN_ON_ONCE(!irqs_disabled());
3045
3046         if (!(cmd->transport_state & CMD_T_ABORTED))
3047                 return 0;
3048         /*
3049          * If cmd has been aborted but either no status is to be sent or it has
3050          * already been sent, just return
3051          */
3052         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3053                 if (send_status)
3054                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3055                 return 1;
3056         }
3057
3058         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3059                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3060
3061         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3062         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3063         trace_target_cmd_complete(cmd);
3064
3065         spin_unlock_irq(&cmd->t_state_lock);
3066         ret = cmd->se_tfo->queue_status(cmd);
3067         if (ret)
3068                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3069         spin_lock_irq(&cmd->t_state_lock);
3070
3071         return 1;
3072 }
3073
3074 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3075 {
3076         int ret;
3077
3078         spin_lock_irq(&cmd->t_state_lock);
3079         ret = __transport_check_aborted_status(cmd, send_status);
3080         spin_unlock_irq(&cmd->t_state_lock);
3081
3082         return ret;
3083 }
3084 EXPORT_SYMBOL(transport_check_aborted_status);
3085
3086 void transport_send_task_abort(struct se_cmd *cmd)
3087 {
3088         unsigned long flags;
3089         int ret;
3090
3091         spin_lock_irqsave(&cmd->t_state_lock, flags);
3092         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3093                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3094                 return;
3095         }
3096         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3097
3098         /*
3099          * If there are still expected incoming fabric WRITEs, we wait
3100          * until until they have completed before sending a TASK_ABORTED
3101          * response.  This response with TASK_ABORTED status will be
3102          * queued back to fabric module by transport_check_aborted_status().
3103          */
3104         if (cmd->data_direction == DMA_TO_DEVICE) {
3105                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3106                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3107                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3108                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3109                                 goto send_abort;
3110                         }
3111                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3112                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3113                         return;
3114                 }
3115         }
3116 send_abort:
3117         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3118
3119         transport_lun_remove_cmd(cmd);
3120
3121         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3122                  cmd->t_task_cdb[0], cmd->tag);
3123
3124         trace_target_cmd_complete(cmd);
3125         ret = cmd->se_tfo->queue_status(cmd);
3126         if (ret)
3127                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3128 }
3129
3130 static void target_tmr_work(struct work_struct *work)
3131 {
3132         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3133         struct se_device *dev = cmd->se_dev;
3134         struct se_tmr_req *tmr = cmd->se_tmr_req;
3135         unsigned long flags;
3136         int ret;
3137
3138         spin_lock_irqsave(&cmd->t_state_lock, flags);
3139         if (cmd->transport_state & CMD_T_ABORTED) {
3140                 tmr->response = TMR_FUNCTION_REJECTED;
3141                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3142                 goto check_stop;
3143         }
3144         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3145
3146         switch (tmr->function) {
3147         case TMR_ABORT_TASK:
3148                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3149                 break;
3150         case TMR_ABORT_TASK_SET:
3151         case TMR_CLEAR_ACA:
3152         case TMR_CLEAR_TASK_SET:
3153                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3154                 break;
3155         case TMR_LUN_RESET:
3156                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3157                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3158                                          TMR_FUNCTION_REJECTED;
3159                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3160                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3161                                                cmd->orig_fe_lun, 0x29,
3162                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3163                 }
3164                 break;
3165         case TMR_TARGET_WARM_RESET:
3166                 tmr->response = TMR_FUNCTION_REJECTED;
3167                 break;
3168         case TMR_TARGET_COLD_RESET:
3169                 tmr->response = TMR_FUNCTION_REJECTED;
3170                 break;
3171         default:
3172                 pr_err("Uknown TMR function: 0x%02x.\n",
3173                                 tmr->function);
3174                 tmr->response = TMR_FUNCTION_REJECTED;
3175                 break;
3176         }
3177
3178         spin_lock_irqsave(&cmd->t_state_lock, flags);
3179         if (cmd->transport_state & CMD_T_ABORTED) {
3180                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3181                 goto check_stop;
3182         }
3183         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3184
3185         cmd->se_tfo->queue_tm_rsp(cmd);
3186
3187 check_stop:
3188         transport_cmd_check_stop_to_fabric(cmd);
3189 }
3190
3191 int transport_generic_handle_tmr(
3192         struct se_cmd *cmd)
3193 {
3194         unsigned long flags;
3195         bool aborted = false;
3196
3197         spin_lock_irqsave(&cmd->t_state_lock, flags);
3198         if (cmd->transport_state & CMD_T_ABORTED) {
3199                 aborted = true;
3200         } else {
3201                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3202                 cmd->transport_state |= CMD_T_ACTIVE;
3203         }
3204         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3205
3206         if (aborted) {
3207                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3208                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3209                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3210                 transport_cmd_check_stop_to_fabric(cmd);
3211                 return 0;
3212         }
3213
3214         INIT_WORK(&cmd->work, target_tmr_work);
3215         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3216         return 0;
3217 }
3218 EXPORT_SYMBOL(transport_generic_handle_tmr);
3219
3220 bool
3221 target_check_wce(struct se_device *dev)
3222 {
3223         bool wce = false;
3224
3225         if (dev->transport->get_write_cache)
3226                 wce = dev->transport->get_write_cache(dev);
3227         else if (dev->dev_attrib.emulate_write_cache > 0)
3228                 wce = true;
3229
3230         return wce;
3231 }
3232
3233 bool
3234 target_check_fua(struct se_device *dev)
3235 {
3236         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3237 }