drivers/target/target_core_transport.c

   1 /*******************************************************************************
   2  * Filename:  target_core_transport.c
   3  *
   4  * This file contains the Generic Target Engine Core.
   5  *
   6  * (c) Copyright 2002-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/net.h>
  27 #include <linux/delay.h>
  28 #include <linux/string.h>
  29 #include <linux/timer.h>
  30 #include <linux/slab.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/kthread.h>
  33 #include <linux/in.h>
  34 #include <linux/cdrom.h>
  35 #include <linux/module.h>
  36 #include <linux/ratelimit.h>
  37 #include <linux/vmalloc.h>
  38 #include <asm/unaligned.h>
  39 #include <net/sock.h>
  40 #include <net/tcp.h>
  41 #include <scsi/scsi_proto.h>
  42 #include <scsi/scsi_common.h>
  43
  44 #include <target/target_core_base.h>
  45 #include <target/target_core_backend.h>
  46 #include <target/target_core_fabric.h>
  47
  48 #include "target_core_internal.h"
  49 #include "target_core_alua.h"
  50 #include "target_core_pr.h"
  51 #include "target_core_ua.h"
  52
  53 #define CREATE_TRACE_POINTS
  54 #include <trace/events/target.h>
  55
  56 static struct workqueue_struct *target_completion_wq;
  57 static struct kmem_cache *se_sess_cache;
  58 struct kmem_cache *se_ua_cache;
  59 struct kmem_cache *t10_pr_reg_cache;
  60 struct kmem_cache *t10_alua_lu_gp_cache;
  61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  63 struct kmem_cache *t10_alua_lba_map_cache;
  64 struct kmem_cache *t10_alua_lba_map_mem_cache;
  65
  66 static void transport_complete_task_attr(struct se_cmd *cmd);
  67 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
  68 static void transport_handle_queue_full(struct se_cmd *cmd,
  69                 struct se_device *dev, int err, bool write_pending);
  70 static int transport_put_cmd(struct se_cmd *cmd);
  71 static void target_complete_ok_work(struct work_struct *work);
  72
  73 int init_se_kmem_caches(void)
  74 {
  75         se_sess_cache = kmem_cache_create("se_sess_cache",
  76                         sizeof(struct se_session), __alignof__(struct se_session),
  77                         0, NULL);
  78         if (!se_sess_cache) {
  79                 pr_err("kmem_cache_create() for struct se_session"
  80                                 " failed\n");
  81                 goto out;
  82         }
  83         se_ua_cache = kmem_cache_create("se_ua_cache",
  84                         sizeof(struct se_ua), __alignof__(struct se_ua),
  85                         0, NULL);
  86         if (!se_ua_cache) {
  87                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  88                 goto out_free_sess_cache;
  89         }
  90         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  91                         sizeof(struct t10_pr_registration),
  92                         __alignof__(struct t10_pr_registration), 0, NULL);
  93         if (!t10_pr_reg_cache) {
  94                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  95                                 " failed\n");
  96                 goto out_free_ua_cache;
  97         }
  98         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  99                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
 100                         0, NULL);
 101         if (!t10_alua_lu_gp_cache) {
 102                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
 103                                 " failed\n");
 104                 goto out_free_pr_reg_cache;
 105         }
 106         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
 107                         sizeof(struct t10_alua_lu_gp_member),
 108                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
 109         if (!t10_alua_lu_gp_mem_cache) {
 110                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
 111                                 "cache failed\n");
 112                 goto out_free_lu_gp_cache;
 113         }
 114         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 115                         sizeof(struct t10_alua_tg_pt_gp),
 116                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 117         if (!t10_alua_tg_pt_gp_cache) {
 118                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 119                                 "cache failed\n");
 120                 goto out_free_lu_gp_mem_cache;
 121         }
 122         t10_alua_lba_map_cache = kmem_cache_create(
 123                         "t10_alua_lba_map_cache",
 124                         sizeof(struct t10_alua_lba_map),
 125                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 126         if (!t10_alua_lba_map_cache) {
 127                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 128                                 "cache failed\n");
 129                 goto out_free_tg_pt_gp_cache;
 130         }
 131         t10_alua_lba_map_mem_cache = kmem_cache_create(
 132                         "t10_alua_lba_map_mem_cache",
 133                         sizeof(struct t10_alua_lba_map_member),
 134                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 135         if (!t10_alua_lba_map_mem_cache) {
 136                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 137                                 "cache failed\n");
 138                 goto out_free_lba_map_cache;
 139         }
 140
 141         target_completion_wq = alloc_workqueue("target_completion",
 142                                                WQ_MEM_RECLAIM, 0);
 143         if (!target_completion_wq)
 144                 goto out_free_lba_map_mem_cache;
 145
 146         return 0;
 147
 148 out_free_lba_map_mem_cache:
 149         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 150 out_free_lba_map_cache:
 151         kmem_cache_destroy(t10_alua_lba_map_cache);
 152 out_free_tg_pt_gp_cache:
 153         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 154 out_free_lu_gp_mem_cache:
 155         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 156 out_free_lu_gp_cache:
 157         kmem_cache_destroy(t10_alua_lu_gp_cache);
 158 out_free_pr_reg_cache:
 159         kmem_cache_destroy(t10_pr_reg_cache);
 160 out_free_ua_cache:
 161         kmem_cache_destroy(se_ua_cache);
 162 out_free_sess_cache:
 163         kmem_cache_destroy(se_sess_cache);
 164 out:
 165         return -ENOMEM;
 166 }
 167
 168 void release_se_kmem_caches(void)
 169 {
 170         destroy_workqueue(target_completion_wq);
 171         kmem_cache_destroy(se_sess_cache);
 172         kmem_cache_destroy(se_ua_cache);
 173         kmem_cache_destroy(t10_pr_reg_cache);
 174         kmem_cache_destroy(t10_alua_lu_gp_cache);
 175         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 176         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 177         kmem_cache_destroy(t10_alua_lba_map_cache);
 178         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 179 }
 180
 181 /* This code ensures unique mib indexes are handed out. */
 182 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 183 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 184
 185 /*
 186  * Allocate a new row index for the entry type specified
 187  */
 188 u32 scsi_get_new_index(scsi_index_t type)
 189 {
 190         u32 new_index;
 191
 192         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 193
 194         spin_lock(&scsi_mib_index_lock);
 195         new_index = ++scsi_mib_index[type];
 196         spin_unlock(&scsi_mib_index_lock);
 197
 198         return new_index;
 199 }
 200
 201 void transport_subsystem_check_init(void)
 202 {
 203         int ret;
 204         static int sub_api_initialized;
 205
 206         if (sub_api_initialized)
 207                 return;
 208
 209         ret = request_module("target_core_iblock");
 210         if (ret != 0)
 211                 pr_err("Unable to load target_core_iblock\n");
 212
 213         ret = request_module("target_core_file");
 214         if (ret != 0)
 215                 pr_err("Unable to load target_core_file\n");
 216
 217         ret = request_module("target_core_pscsi");
 218         if (ret != 0)
 219                 pr_err("Unable to load target_core_pscsi\n");
 220
 221         ret = request_module("target_core_user");
 222         if (ret != 0)
 223                 pr_err("Unable to load target_core_user\n");
 224
 225         sub_api_initialized = 1;
 226 }
 227
 228 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
 229 {
 230         struct se_session *se_sess;
 231
 232         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 233         if (!se_sess) {
 234                 pr_err("Unable to allocate struct se_session from"
 235                                 " se_sess_cache\n");
 236                 return ERR_PTR(-ENOMEM);
 237         }
 238         INIT_LIST_HEAD(&se_sess->sess_list);
 239         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 240         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 241         INIT_LIST_HEAD(&se_sess->sess_wait_list);
 242         spin_lock_init(&se_sess->sess_cmd_lock);
 243         se_sess->sup_prot_ops = sup_prot_ops;
 244
 245         return se_sess;
 246 }
 247 EXPORT_SYMBOL(transport_init_session);
 248
 249 int transport_alloc_session_tags(struct se_session *se_sess,
 250                                  unsigned int tag_num, unsigned int tag_size)
 251 {
 252         int rc;
 253
 254         se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
 255                                         GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);
 256         if (!se_sess->sess_cmd_map) {
 257                 se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
 258                 if (!se_sess->sess_cmd_map) {
 259                         pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 260                         return -ENOMEM;
 261                 }
 262         }
 263
 264         rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
 265         if (rc < 0) {
 266                 pr_err("Unable to init se_sess->sess_tag_pool,"
 267                         " tag_num: %u\n", tag_num);
 268                 kvfree(se_sess->sess_cmd_map);
 269                 se_sess->sess_cmd_map = NULL;
 270                 return -ENOMEM;
 271         }
 272
 273         return 0;
 274 }
 275 EXPORT_SYMBOL(transport_alloc_session_tags);
 276
 277 struct se_session *transport_init_session_tags(unsigned int tag_num,
 278                                                unsigned int tag_size,
 279                                                enum target_prot_op sup_prot_ops)
 280 {
 281         struct se_session *se_sess;
 282         int rc;
 283
 284         if (tag_num != 0 && !tag_size) {
 285                 pr_err("init_session_tags called with percpu-ida tag_num:"
 286                        " %u, but zero tag_size\n", tag_num);
 287                 return ERR_PTR(-EINVAL);
 288         }
 289         if (!tag_num && tag_size) {
 290                 pr_err("init_session_tags called with percpu-ida tag_size:"
 291                        " %u, but zero tag_num\n", tag_size);
 292                 return ERR_PTR(-EINVAL);
 293         }
 294
 295         se_sess = transport_init_session(sup_prot_ops);
 296         if (IS_ERR(se_sess))
 297                 return se_sess;
 298
 299         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 300         if (rc < 0) {
 301                 transport_free_session(se_sess);
 302                 return ERR_PTR(-ENOMEM);
 303         }
 304
 305         return se_sess;
 306 }
 307 EXPORT_SYMBOL(transport_init_session_tags);
 308
 309 /*
 310  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 311  */
 312 void __transport_register_session(
 313         struct se_portal_group *se_tpg,
 314         struct se_node_acl *se_nacl,
 315         struct se_session *se_sess,
 316         void *fabric_sess_ptr)
 317 {
 318         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 319         unsigned char buf[PR_REG_ISID_LEN];
 320         unsigned long flags;
 321
 322         se_sess->se_tpg = se_tpg;
 323         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 324         /*
 325          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 326          *
 327          * Only set for struct se_session's that will actually be moving I/O.
 328          * eg: *NOT* discovery sessions.
 329          */
 330         if (se_nacl) {
 331                 /*
 332                  *
 333                  * Determine if fabric allows for T10-PI feature bits exposed to
 334                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 335                  *
 336                  * If so, then always save prot_type on a per se_node_acl node
 337                  * basis and re-instate the previous sess_prot_type to avoid
 338                  * disabling PI from below any previously initiator side
 339                  * registered LUNs.
 340                  */
 341                 if (se_nacl->saved_prot_type)
 342                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 343                 else if (tfo->tpg_check_prot_fabric_only)
 344                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 345                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 346                 /*
 347                  * If the fabric module supports an ISID based TransportID,
 348                  * save this value in binary from the fabric I_T Nexus now.
 349                  */
 350                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 351                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 352                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 353                                         &buf[0], PR_REG_ISID_LEN);
 354                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 355                 }
 356
 357                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 358                 /*
 359                  * The se_nacl->nacl_sess pointer will be set to the
 360                  * last active I_T Nexus for each struct se_node_acl.
 361                  */
 362                 se_nacl->nacl_sess = se_sess;
 363
 364                 list_add_tail(&se_sess->sess_acl_list,
 365                               &se_nacl->acl_sess_list);
 366                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 367         }
 368         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 369
 370         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 371                 se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
 372 }
 373 EXPORT_SYMBOL(__transport_register_session);
 374
 375 void transport_register_session(
 376         struct se_portal_group *se_tpg,
 377         struct se_node_acl *se_nacl,
 378         struct se_session *se_sess,
 379         void *fabric_sess_ptr)
 380 {
 381         unsigned long flags;
 382
 383         spin_lock_irqsave(&se_tpg->session_lock, flags);
 384         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 385         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 386 }
 387 EXPORT_SYMBOL(transport_register_session);
 388
 389 struct se_session *
 390 target_alloc_session(struct se_portal_group *tpg,
 391                      unsigned int tag_num, unsigned int tag_size,
 392                      enum target_prot_op prot_op,
 393                      const char *initiatorname, void *private,
 394                      int (*callback)(struct se_portal_group *,
 395                                      struct se_session *, void *))
 396 {
 397         struct se_session *sess;
 398
 399         /*
 400          * If the fabric driver is using percpu-ida based pre allocation
 401          * of I/O descriptor tags, go ahead and perform that setup now..
 402          */
 403         if (tag_num != 0)
 404                 sess = transport_init_session_tags(tag_num, tag_size, prot_op);
 405         else
 406                 sess = transport_init_session(prot_op);
 407
 408         if (IS_ERR(sess))
 409                 return sess;
 410
 411         sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
 412                                         (unsigned char *)initiatorname);
 413         if (!sess->se_node_acl) {
 414                 transport_free_session(sess);
 415                 return ERR_PTR(-EACCES);
 416         }
 417         /*
 418          * Go ahead and perform any remaining fabric setup that is
 419          * required before transport_register_session().
 420          */
 421         if (callback != NULL) {
 422                 int rc = callback(tpg, sess, private);
 423                 if (rc) {
 424                         transport_free_session(sess);
 425                         return ERR_PTR(rc);
 426                 }
 427         }
 428
 429         transport_register_session(tpg, sess->se_node_acl, sess, private);
 430         return sess;
 431 }
 432 EXPORT_SYMBOL(target_alloc_session);
 433
 434 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 435 {
 436         struct se_session *se_sess;
 437         ssize_t len = 0;
 438
 439         spin_lock_bh(&se_tpg->session_lock);
 440         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 441                 if (!se_sess->se_node_acl)
 442                         continue;
 443                 if (!se_sess->se_node_acl->dynamic_node_acl)
 444                         continue;
 445                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 446                         break;
 447
 448                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 449                                 se_sess->se_node_acl->initiatorname);
 450                 len += 1; /* Include NULL terminator */
 451         }
 452         spin_unlock_bh(&se_tpg->session_lock);
 453
 454         return len;
 455 }
 456 EXPORT_SYMBOL(target_show_dynamic_sessions);
 457
 458 static void target_complete_nacl(struct kref *kref)
 459 {
 460         struct se_node_acl *nacl = container_of(kref,
 461                                 struct se_node_acl, acl_kref);
 462         struct se_portal_group *se_tpg = nacl->se_tpg;
 463
 464         if (!nacl->dynamic_stop) {
 465                 complete(&nacl->acl_free_comp);
 466                 return;
 467         }
 468
 469         mutex_lock(&se_tpg->acl_node_mutex);
 470         list_del_init(&nacl->acl_list);
 471         mutex_unlock(&se_tpg->acl_node_mutex);
 472
 473         core_tpg_wait_for_nacl_pr_ref(nacl);
 474         core_free_device_list_for_node(nacl, se_tpg);
 475         kfree(nacl);
 476 }
 477
 478 void target_put_nacl(struct se_node_acl *nacl)
 479 {
 480         kref_put(&nacl->acl_kref, target_complete_nacl);
 481 }
 482 EXPORT_SYMBOL(target_put_nacl);
 483
 484 void transport_deregister_session_configfs(struct se_session *se_sess)
 485 {
 486         struct se_node_acl *se_nacl;
 487         unsigned long flags;
 488         /*
 489          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 490          */
 491         se_nacl = se_sess->se_node_acl;
 492         if (se_nacl) {
 493                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 494                 if (!list_empty(&se_sess->sess_acl_list))
 495                         list_del_init(&se_sess->sess_acl_list);
 496                 /*
 497                  * If the session list is empty, then clear the pointer.
 498                  * Otherwise, set the struct se_session pointer from the tail
 499                  * element of the per struct se_node_acl active session list.
 500                  */
 501                 if (list_empty(&se_nacl->acl_sess_list))
 502                         se_nacl->nacl_sess = NULL;
 503                 else {
 504                         se_nacl->nacl_sess = container_of(
 505                                         se_nacl->acl_sess_list.prev,
 506                                         struct se_session, sess_acl_list);
 507                 }
 508                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 509         }
 510 }
 511 EXPORT_SYMBOL(transport_deregister_session_configfs);
 512
 513 void transport_free_session(struct se_session *se_sess)
 514 {
 515         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 516
 517         /*
 518          * Drop the se_node_acl->nacl_kref obtained from within
 519          * core_tpg_get_initiator_node_acl().
 520          */
 521         if (se_nacl) {
 522                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 523                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 524                 unsigned long flags;
 525
 526                 se_sess->se_node_acl = NULL;
 527
 528                 /*
 529                  * Also determine if we need to drop the extra ->cmd_kref if
 530                  * it had been previously dynamically generated, and
 531                  * the endpoint is not caching dynamic ACLs.
 532                  */
 533                 mutex_lock(&se_tpg->acl_node_mutex);
 534                 if (se_nacl->dynamic_node_acl &&
 535                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 536                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 537                         if (list_empty(&se_nacl->acl_sess_list))
 538                                 se_nacl->dynamic_stop = true;
 539                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 540
 541                         if (se_nacl->dynamic_stop)
 542                                 list_del_init(&se_nacl->acl_list);
 543                 }
 544                 mutex_unlock(&se_tpg->acl_node_mutex);
 545
 546                 if (se_nacl->dynamic_stop)
 547                         target_put_nacl(se_nacl);
 548
 549                 target_put_nacl(se_nacl);
 550         }
 551         if (se_sess->sess_cmd_map) {
 552                 percpu_ida_destroy(&se_sess->sess_tag_pool);
 553                 kvfree(se_sess->sess_cmd_map);
 554         }
 555         kmem_cache_free(se_sess_cache, se_sess);
 556 }
 557 EXPORT_SYMBOL(transport_free_session);
 558
 559 void transport_deregister_session(struct se_session *se_sess)
 560 {
 561         struct se_portal_group *se_tpg = se_sess->se_tpg;
 562         unsigned long flags;
 563
 564         if (!se_tpg) {
 565                 transport_free_session(se_sess);
 566                 return;
 567         }
 568
 569         spin_lock_irqsave(&se_tpg->session_lock, flags);
 570         list_del(&se_sess->sess_list);
 571         se_sess->se_tpg = NULL;
 572         se_sess->fabric_sess_ptr = NULL;
 573         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 574
 575         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 576                 se_tpg->se_tpg_tfo->get_fabric_name());
 577         /*
 578          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 579          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 580          * removal context from within transport_free_session() code.
 581          *
 582          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 583          * to release all remaining generate_node_acl=1 created ACL resources.
 584          */
 585
 586         transport_free_session(se_sess);
 587 }
 588 EXPORT_SYMBOL(transport_deregister_session);
 589
 590 static void target_remove_from_state_list(struct se_cmd *cmd)
 591 {
 592         struct se_device *dev = cmd->se_dev;
 593         unsigned long flags;
 594
 595         if (!dev)
 596                 return;
 597
 598         spin_lock_irqsave(&dev->execute_task_lock, flags);
 599         if (cmd->state_active) {
 600                 list_del(&cmd->state_list);
 601                 cmd->state_active = false;
 602         }
 603         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 604 }
 605
 606 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 607 {
 608         unsigned long flags;
 609
 610         target_remove_from_state_list(cmd);
 611
 612         /*
 613          * Clear struct se_cmd->se_lun before the handoff to FE.
 614          */
 615         cmd->se_lun = NULL;
 616
 617         spin_lock_irqsave(&cmd->t_state_lock, flags);
 618         /*
 619          * Determine if frontend context caller is requesting the stopping of
 620          * this command for frontend exceptions.
 621          */
 622         if (cmd->transport_state & CMD_T_STOP) {
 623                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 624                         __func__, __LINE__, cmd->tag);
 625
 626                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 627
 628                 complete_all(&cmd->t_transport_stop_comp);
 629                 return 1;
 630         }
 631         cmd->transport_state &= ~CMD_T_ACTIVE;
 632         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 633
 634         /*
 635          * Some fabric modules like tcm_loop can release their internally
 636          * allocated I/O reference and struct se_cmd now.
 637          *
 638          * Fabric modules are expected to return '1' here if the se_cmd being
 639          * passed is released at this point, or zero if not being released.
 640          */
 641         return cmd->se_tfo->check_stop_free(cmd);
 642 }
 643
 644 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 645 {
 646         struct se_lun *lun = cmd->se_lun;
 647
 648         if (!lun)
 649                 return;
 650
 651         if (cmpxchg(&cmd->lun_ref_active, true, false))
 652                 percpu_ref_put(&lun->lun_ref);
 653 }
 654
 655 int transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 656 {
 657         bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
 658         int ret = 0;
 659
 660         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
 661                 transport_lun_remove_cmd(cmd);
 662         /*
 663          * Allow the fabric driver to unmap any resources before
 664          * releasing the descriptor via TFO->release_cmd()
 665          */
 666         if (remove)
 667                 cmd->se_tfo->aborted_task(cmd);
 668
 669         if (transport_cmd_check_stop_to_fabric(cmd))
 670                 return 1;
 671         if (remove && ack_kref)
 672                 ret = transport_put_cmd(cmd);
 673
 674         return ret;
 675 }
 676
 677 static void target_complete_failure_work(struct work_struct *work)
 678 {
 679         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 680
 681         transport_generic_request_failure(cmd,
 682                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 683 }
 684
 685 /*
 686  * Used when asking transport to copy Sense Data from the underlying
 687  * Linux/SCSI struct scsi_cmnd
 688  */
 689 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 690 {
 691         struct se_device *dev = cmd->se_dev;
 692
 693         WARN_ON(!cmd->se_lun);
 694
 695         if (!dev)
 696                 return NULL;
 697
 698         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 699                 return NULL;
 700
 701         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 702
 703         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 704                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 705         return cmd->sense_buffer;
 706 }
 707
 708 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
 709 {
 710         unsigned char *cmd_sense_buf;
 711         unsigned long flags;
 712
 713         spin_lock_irqsave(&cmd->t_state_lock, flags);
 714         cmd_sense_buf = transport_get_sense_buffer(cmd);
 715         if (!cmd_sense_buf) {
 716                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 717                 return;
 718         }
 719
 720         cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
 721         memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
 722         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 723 }
 724 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
 725
 726 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 727 {
 728         struct se_device *dev = cmd->se_dev;
 729         int success;
 730         unsigned long flags;
 731
 732         cmd->scsi_status = scsi_status;
 733
 734         spin_lock_irqsave(&cmd->t_state_lock, flags);
 735         switch (cmd->scsi_status) {
 736         case SAM_STAT_CHECK_CONDITION:
 737                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 738                         success = 1;
 739                 else
 740                         success = 0;
 741                 break;
 742         default:
 743                 success = 1;
 744                 break;
 745         }
 746
 747         /*
 748          * Check for case where an explicit ABORT_TASK has been received
 749          * and transport_wait_for_tasks() will be waiting for completion..
 750          */
 751         if (cmd->transport_state & CMD_T_ABORTED ||
 752             cmd->transport_state & CMD_T_STOP) {
 753                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 754                 /*
 755                  * If COMPARE_AND_WRITE was stopped by __transport_wait_for_tasks(),
 756                  * release se_device->caw_sem obtained by sbc_compare_and_write()
 757                  * since target_complete_ok_work() or target_complete_failure_work()
 758                  * won't be called to invoke the normal CAW completion callbacks.
 759                  */
 760                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
 761                         up(&dev->caw_sem);
 762                 }
 763                 complete_all(&cmd->t_transport_stop_comp);
 764                 return;
 765         } else if (!success) {
 766                 INIT_WORK(&cmd->work, target_complete_failure_work);
 767         } else {
 768                 INIT_WORK(&cmd->work, target_complete_ok_work);
 769         }
 770
 771         cmd->t_state = TRANSPORT_COMPLETE;
 772         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 773         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 774
 775         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 776                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 777         else
 778                 queue_work(target_completion_wq, &cmd->work);
 779 }
 780 EXPORT_SYMBOL(target_complete_cmd);
 781
 782 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 783 {
 784         if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
 785                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 786                         cmd->residual_count += cmd->data_length - length;
 787                 } else {
 788                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 789                         cmd->residual_count = cmd->data_length - length;
 790                 }
 791
 792                 cmd->data_length = length;
 793         }
 794
 795         target_complete_cmd(cmd, scsi_status);
 796 }
 797 EXPORT_SYMBOL(target_complete_cmd_with_length);
 798
 799 static void target_add_to_state_list(struct se_cmd *cmd)
 800 {
 801         struct se_device *dev = cmd->se_dev;
 802         unsigned long flags;
 803
 804         spin_lock_irqsave(&dev->execute_task_lock, flags);
 805         if (!cmd->state_active) {
 806                 list_add_tail(&cmd->state_list, &dev->state_list);
 807                 cmd->state_active = true;
 808         }
 809         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 810 }
 811
 812 /*
 813  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 814  */
 815 static void transport_write_pending_qf(struct se_cmd *cmd);
 816 static void transport_complete_qf(struct se_cmd *cmd);
 817
 818 void target_qf_do_work(struct work_struct *work)
 819 {
 820         struct se_device *dev = container_of(work, struct se_device,
 821                                         qf_work_queue);
 822         LIST_HEAD(qf_cmd_list);
 823         struct se_cmd *cmd, *cmd_tmp;
 824
 825         spin_lock_irq(&dev->qf_cmd_lock);
 826         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 827         spin_unlock_irq(&dev->qf_cmd_lock);
 828
 829         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 830                 list_del(&cmd->se_qf_node);
 831                 atomic_dec_mb(&dev->dev_qf_count);
 832
 833                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 834                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
 835                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 836                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 837                         : "UNKNOWN");
 838
 839                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 840                         transport_write_pending_qf(cmd);
 841                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 842                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 843                         transport_complete_qf(cmd);
 844         }
 845 }
 846
 847 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 848 {
 849         switch (cmd->data_direction) {
 850         case DMA_NONE:
 851                 return "NONE";
 852         case DMA_FROM_DEVICE:
 853                 return "READ";
 854         case DMA_TO_DEVICE:
 855                 return "WRITE";
 856         case DMA_BIDIRECTIONAL:
 857                 return "BIDI";
 858         default:
 859                 break;
 860         }
 861
 862         return "UNKNOWN";
 863 }
 864
 865 void transport_dump_dev_state(
 866         struct se_device *dev,
 867         char *b,
 868         int *bl)
 869 {
 870         *bl += sprintf(b + *bl, "Status: ");
 871         if (dev->export_count)
 872                 *bl += sprintf(b + *bl, "ACTIVATED");
 873         else
 874                 *bl += sprintf(b + *bl, "DEACTIVATED");
 875
 876         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 877         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 878                 dev->dev_attrib.block_size,
 879                 dev->dev_attrib.hw_max_sectors);
 880         *bl += sprintf(b + *bl, "        ");
 881 }
 882
 883 void transport_dump_vpd_proto_id(
 884         struct t10_vpd *vpd,
 885         unsigned char *p_buf,
 886         int p_buf_len)
 887 {
 888         unsigned char buf[VPD_TMP_BUF_SIZE];
 889         int len;
 890
 891         memset(buf, 0, VPD_TMP_BUF_SIZE);
 892         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 893
 894         switch (vpd->protocol_identifier) {
 895         case 0x00:
 896                 sprintf(buf+len, "Fibre Channel\n");
 897                 break;
 898         case 0x10:
 899                 sprintf(buf+len, "Parallel SCSI\n");
 900                 break;
 901         case 0x20:
 902                 sprintf(buf+len, "SSA\n");
 903                 break;
 904         case 0x30:
 905                 sprintf(buf+len, "IEEE 1394\n");
 906                 break;
 907         case 0x40:
 908                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
 909                                 " Protocol\n");
 910                 break;
 911         case 0x50:
 912                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
 913                 break;
 914         case 0x60:
 915                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
 916                 break;
 917         case 0x70:
 918                 sprintf(buf+len, "Automation/Drive Interface Transport"
 919                                 " Protocol\n");
 920                 break;
 921         case 0x80:
 922                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
 923                 break;
 924         default:
 925                 sprintf(buf+len, "Unknown 0x%02x\n",
 926                                 vpd->protocol_identifier);
 927                 break;
 928         }
 929
 930         if (p_buf)
 931                 strncpy(p_buf, buf, p_buf_len);
 932         else
 933                 pr_debug("%s", buf);
 934 }
 935
 936 void
 937 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
 938 {
 939         /*
 940          * Check if the Protocol Identifier Valid (PIV) bit is set..
 941          *
 942          * from spc3r23.pdf section 7.5.1
 943          */
 944          if (page_83[1] & 0x80) {
 945                 vpd->protocol_identifier = (page_83[0] & 0xf0);
 946                 vpd->protocol_identifier_set = 1;
 947                 transport_dump_vpd_proto_id(vpd, NULL, 0);
 948         }
 949 }
 950 EXPORT_SYMBOL(transport_set_vpd_proto_id);
 951
 952 int transport_dump_vpd_assoc(
 953         struct t10_vpd *vpd,
 954         unsigned char *p_buf,
 955         int p_buf_len)
 956 {
 957         unsigned char buf[VPD_TMP_BUF_SIZE];
 958         int ret = 0;
 959         int len;
 960
 961         memset(buf, 0, VPD_TMP_BUF_SIZE);
 962         len = sprintf(buf, "T10 VPD Identifier Association: ");
 963
 964         switch (vpd->association) {
 965         case 0x00:
 966                 sprintf(buf+len, "addressed logical unit\n");
 967                 break;
 968         case 0x10:
 969                 sprintf(buf+len, "target port\n");
 970                 break;
 971         case 0x20:
 972                 sprintf(buf+len, "SCSI target device\n");
 973                 break;
 974         default:
 975                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
 976                 ret = -EINVAL;
 977                 break;
 978         }
 979
 980         if (p_buf)
 981                 strncpy(p_buf, buf, p_buf_len);
 982         else
 983                 pr_debug("%s", buf);
 984
 985         return ret;
 986 }
 987
 988 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
 989 {
 990         /*
 991          * The VPD identification association..
 992          *
 993          * from spc3r23.pdf Section 7.6.3.1 Table 297
 994          */
 995         vpd->association = (page_83[1] & 0x30);
 996         return transport_dump_vpd_assoc(vpd, NULL, 0);
 997 }
 998 EXPORT_SYMBOL(transport_set_vpd_assoc);
 999
1000 int transport_dump_vpd_ident_type(
1001         struct t10_vpd *vpd,
1002         unsigned char *p_buf,
1003         int p_buf_len)
1004 {
1005         unsigned char buf[VPD_TMP_BUF_SIZE];
1006         int ret = 0;
1007         int len;
1008
1009         memset(buf, 0, VPD_TMP_BUF_SIZE);
1010         len = sprintf(buf, "T10 VPD Identifier Type: ");
1011
1012         switch (vpd->device_identifier_type) {
1013         case 0x00:
1014                 sprintf(buf+len, "Vendor specific\n");
1015                 break;
1016         case 0x01:
1017                 sprintf(buf+len, "T10 Vendor ID based\n");
1018                 break;
1019         case 0x02:
1020                 sprintf(buf+len, "EUI-64 based\n");
1021                 break;
1022         case 0x03:
1023                 sprintf(buf+len, "NAA\n");
1024                 break;
1025         case 0x04:
1026                 sprintf(buf+len, "Relative target port identifier\n");
1027                 break;
1028         case 0x08:
1029                 sprintf(buf+len, "SCSI name string\n");
1030                 break;
1031         default:
1032                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1033                                 vpd->device_identifier_type);
1034                 ret = -EINVAL;
1035                 break;
1036         }
1037
1038         if (p_buf) {
1039                 if (p_buf_len < strlen(buf)+1)
1040                         return -EINVAL;
1041                 strncpy(p_buf, buf, p_buf_len);
1042         } else {
1043                 pr_debug("%s", buf);
1044         }
1045
1046         return ret;
1047 }
1048
1049 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1050 {
1051         /*
1052          * The VPD identifier type..
1053          *
1054          * from spc3r23.pdf Section 7.6.3.1 Table 298
1055          */
1056         vpd->device_identifier_type = (page_83[1] & 0x0f);
1057         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1058 }
1059 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1060
1061 int transport_dump_vpd_ident(
1062         struct t10_vpd *vpd,
1063         unsigned char *p_buf,
1064         int p_buf_len)
1065 {
1066         unsigned char buf[VPD_TMP_BUF_SIZE];
1067         int ret = 0;
1068
1069         memset(buf, 0, VPD_TMP_BUF_SIZE);
1070
1071         switch (vpd->device_identifier_code_set) {
1072         case 0x01: /* Binary */
1073                 snprintf(buf, sizeof(buf),
1074                         "T10 VPD Binary Device Identifier: %s\n",
1075                         &vpd->device_identifier[0]);
1076                 break;
1077         case 0x02: /* ASCII */
1078                 snprintf(buf, sizeof(buf),
1079                         "T10 VPD ASCII Device Identifier: %s\n",
1080                         &vpd->device_identifier[0]);
1081                 break;
1082         case 0x03: /* UTF-8 */
1083                 snprintf(buf, sizeof(buf),
1084                         "T10 VPD UTF-8 Device Identifier: %s\n",
1085                         &vpd->device_identifier[0]);
1086                 break;
1087         default:
1088                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1089                         " 0x%02x", vpd->device_identifier_code_set);
1090                 ret = -EINVAL;
1091                 break;
1092         }
1093
1094         if (p_buf)
1095                 strncpy(p_buf, buf, p_buf_len);
1096         else
1097                 pr_debug("%s", buf);
1098
1099         return ret;
1100 }
1101
1102 int
1103 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1104 {
1105         static const char hex_str[] = "0123456789abcdef";
1106         int j = 0, i = 4; /* offset to start of the identifier */
1107
1108         /*
1109          * The VPD Code Set (encoding)
1110          *
1111          * from spc3r23.pdf Section 7.6.3.1 Table 296
1112          */
1113         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1114         switch (vpd->device_identifier_code_set) {
1115         case 0x01: /* Binary */
1116                 vpd->device_identifier[j++] =
1117                                 hex_str[vpd->device_identifier_type];
1118                 while (i < (4 + page_83[3])) {
1119                         vpd->device_identifier[j++] =
1120                                 hex_str[(page_83[i] & 0xf0) >> 4];
1121                         vpd->device_identifier[j++] =
1122                                 hex_str[page_83[i] & 0x0f];
1123                         i++;
1124                 }
1125                 break;
1126         case 0x02: /* ASCII */
1127         case 0x03: /* UTF-8 */
1128                 while (i < (4 + page_83[3]))
1129                         vpd->device_identifier[j++] = page_83[i++];
1130                 break;
1131         default:
1132                 break;
1133         }
1134
1135         return transport_dump_vpd_ident(vpd, NULL, 0);
1136 }
1137 EXPORT_SYMBOL(transport_set_vpd_ident);
1138
1139 static sense_reason_t
1140 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1141                                unsigned int size)
1142 {
1143         u32 mtl;
1144
1145         if (!cmd->se_tfo->max_data_sg_nents)
1146                 return TCM_NO_SENSE;
1147         /*
1148          * Check if fabric enforced maximum SGL entries per I/O descriptor
1149          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1150          * residual_count and reduce original cmd->data_length to maximum
1151          * length based on single PAGE_SIZE entry scatter-lists.
1152          */
1153         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1154         if (cmd->data_length > mtl) {
1155                 /*
1156                  * If an existing CDB overflow is present, calculate new residual
1157                  * based on CDB size minus fabric maximum transfer length.
1158                  *
1159                  * If an existing CDB underflow is present, calculate new residual
1160                  * based on original cmd->data_length minus fabric maximum transfer
1161                  * length.
1162                  *
1163                  * Otherwise, set the underflow residual based on cmd->data_length
1164                  * minus fabric maximum transfer length.
1165                  */
1166                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1167                         cmd->residual_count = (size - mtl);
1168                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1169                         u32 orig_dl = size + cmd->residual_count;
1170                         cmd->residual_count = (orig_dl - mtl);
1171                 } else {
1172                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1173                         cmd->residual_count = (cmd->data_length - mtl);
1174                 }
1175                 cmd->data_length = mtl;
1176                 /*
1177                  * Reset sbc_check_prot() calculated protection payload
1178                  * length based upon the new smaller MTL.
1179                  */
1180                 if (cmd->prot_length) {
1181                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1182                         cmd->prot_length = dev->prot_length * sectors;
1183                 }
1184         }
1185         return TCM_NO_SENSE;
1186 }
1187
1188 sense_reason_t
1189 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1190 {
1191         struct se_device *dev = cmd->se_dev;
1192
1193         if (cmd->unknown_data_length) {
1194                 cmd->data_length = size;
1195         } else if (size != cmd->data_length) {
1196                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1197                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1198                         " 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1199                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1200
1201                 if (cmd->data_direction == DMA_TO_DEVICE) {
1202                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1203                                 pr_err_ratelimited("Rejecting underflow/overflow"
1204                                                    " for WRITE data CDB\n");
1205                                 return TCM_INVALID_CDB_FIELD;
1206                         }
1207                         /*
1208                          * Some fabric drivers like iscsi-target still expect to
1209                          * always reject overflow writes.  Reject this case until
1210                          * full fabric driver level support for overflow writes
1211                          * is introduced tree-wide.
1212                          */
1213                         if (size > cmd->data_length) {
1214                                 pr_err_ratelimited("Rejecting overflow for"
1215                                                    " WRITE control CDB\n");
1216                                 return TCM_INVALID_CDB_FIELD;
1217                         }
1218                 }
1219                 /*
1220                  * Reject READ_* or WRITE_* with overflow/underflow for
1221                  * type SCF_SCSI_DATA_CDB.
1222                  */
1223                 if (dev->dev_attrib.block_size != 512)  {
1224                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1225                                 " CDB on non 512-byte sector setup subsystem"
1226                                 " plugin: %s\n", dev->transport->name);
1227                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1228                         return TCM_INVALID_CDB_FIELD;
1229                 }
1230                 /*
1231                  * For the overflow case keep the existing fabric provided
1232                  * ->data_length.  Otherwise for the underflow case, reset
1233                  * ->data_length to the smaller SCSI expected data transfer
1234                  * length.
1235                  */
1236                 if (size > cmd->data_length) {
1237                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1238                         cmd->residual_count = (size - cmd->data_length);
1239                 } else {
1240                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1241                         cmd->residual_count = (cmd->data_length - size);
1242                         cmd->data_length = size;
1243                 }
1244         }
1245
1246         return target_check_max_data_sg_nents(cmd, dev, size);
1247
1248 }
1249
1250 /*
1251  * Used by fabric modules containing a local struct se_cmd within their
1252  * fabric dependent per I/O descriptor.
1253  *
1254  * Preserves the value of @cmd->tag.
1255  */
1256 void transport_init_se_cmd(
1257         struct se_cmd *cmd,
1258         const struct target_core_fabric_ops *tfo,
1259         struct se_session *se_sess,
1260         u32 data_length,
1261         int data_direction,
1262         int task_attr,
1263         unsigned char *sense_buffer)
1264 {
1265         INIT_LIST_HEAD(&cmd->se_delayed_node);
1266         INIT_LIST_HEAD(&cmd->se_qf_node);
1267         INIT_LIST_HEAD(&cmd->se_cmd_list);
1268         INIT_LIST_HEAD(&cmd->state_list);
1269         init_completion(&cmd->t_transport_stop_comp);
1270         init_completion(&cmd->cmd_wait_comp);
1271         spin_lock_init(&cmd->t_state_lock);
1272         INIT_WORK(&cmd->work, NULL);
1273         kref_init(&cmd->cmd_kref);
1274
1275         cmd->se_tfo = tfo;
1276         cmd->se_sess = se_sess;
1277         cmd->data_length = data_length;
1278         cmd->data_direction = data_direction;
1279         cmd->sam_task_attr = task_attr;
1280         cmd->sense_buffer = sense_buffer;
1281
1282         cmd->state_active = false;
1283 }
1284 EXPORT_SYMBOL(transport_init_se_cmd);
1285
1286 static sense_reason_t
1287 transport_check_alloc_task_attr(struct se_cmd *cmd)
1288 {
1289         struct se_device *dev = cmd->se_dev;
1290
1291         /*
1292          * Check if SAM Task Attribute emulation is enabled for this
1293          * struct se_device storage object
1294          */
1295         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1296                 return 0;
1297
1298         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1299                 pr_debug("SAM Task Attribute ACA"
1300                         " emulation is not supported\n");
1301                 return TCM_INVALID_CDB_FIELD;
1302         }
1303
1304         return 0;
1305 }
1306
1307 sense_reason_t
1308 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1309 {
1310         struct se_device *dev = cmd->se_dev;
1311         sense_reason_t ret;
1312
1313         /*
1314          * Ensure that the received CDB is less than the max (252 + 8) bytes
1315          * for VARIABLE_LENGTH_CMD
1316          */
1317         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1318                 pr_err("Received SCSI CDB with command_size: %d that"
1319                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1320                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1321                 return TCM_INVALID_CDB_FIELD;
1322         }
1323         /*
1324          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1325          * allocate the additional extended CDB buffer now..  Otherwise
1326          * setup the pointer from __t_task_cdb to t_task_cdb.
1327          */
1328         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1329                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1330                                                 GFP_KERNEL);
1331                 if (!cmd->t_task_cdb) {
1332                         pr_err("Unable to allocate cmd->t_task_cdb"
1333                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1334                                 scsi_command_size(cdb),
1335                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1336                         return TCM_OUT_OF_RESOURCES;
1337                 }
1338         } else
1339                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1340         /*
1341          * Copy the original CDB into cmd->
1342          */
1343         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1344
1345         trace_target_sequencer_start(cmd);
1346
1347         ret = dev->transport->parse_cdb(cmd);
1348         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1349                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1350                                     cmd->se_tfo->get_fabric_name(),
1351                                     cmd->se_sess->se_node_acl->initiatorname,
1352                                     cmd->t_task_cdb[0]);
1353         if (ret)
1354                 return ret;
1355
1356         ret = transport_check_alloc_task_attr(cmd);
1357         if (ret)
1358                 return ret;
1359
1360         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1361         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1362         return 0;
1363 }
1364 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1365
1366 /*
1367  * Used by fabric module frontends to queue tasks directly.
1368  * May only be used from process context.
1369  */
1370 int transport_handle_cdb_direct(
1371         struct se_cmd *cmd)
1372 {
1373         sense_reason_t ret;
1374
1375         if (!cmd->se_lun) {
1376                 dump_stack();
1377                 pr_err("cmd->se_lun is NULL\n");
1378                 return -EINVAL;
1379         }
1380         if (in_interrupt()) {
1381                 dump_stack();
1382                 pr_err("transport_generic_handle_cdb cannot be called"
1383                                 " from interrupt context\n");
1384                 return -EINVAL;
1385         }
1386         /*
1387          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1388          * outstanding descriptors are handled correctly during shutdown via
1389          * transport_wait_for_tasks()
1390          *
1391          * Also, we don't take cmd->t_state_lock here as we only expect
1392          * this to be called for initial descriptor submission.
1393          */
1394         cmd->t_state = TRANSPORT_NEW_CMD;
1395         cmd->transport_state |= CMD_T_ACTIVE;
1396
1397         /*
1398          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1399          * so follow TRANSPORT_NEW_CMD processing thread context usage
1400          * and call transport_generic_request_failure() if necessary..
1401          */
1402         ret = transport_generic_new_cmd(cmd);
1403         if (ret)
1404                 transport_generic_request_failure(cmd, ret);
1405         return 0;
1406 }
1407 EXPORT_SYMBOL(transport_handle_cdb_direct);
1408
1409 sense_reason_t
1410 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1411                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1412 {
1413         if (!sgl || !sgl_count)
1414                 return 0;
1415
1416         /*
1417          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1418          * scatterlists already have been set to follow what the fabric
1419          * passes for the original expected data transfer length.
1420          */
1421         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1422                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1423                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1424                 return TCM_INVALID_CDB_FIELD;
1425         }
1426
1427         cmd->t_data_sg = sgl;
1428         cmd->t_data_nents = sgl_count;
1429         cmd->t_bidi_data_sg = sgl_bidi;
1430         cmd->t_bidi_data_nents = sgl_bidi_count;
1431
1432         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1433         return 0;
1434 }
1435
1436 /*
1437  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1438  *                       se_cmd + use pre-allocated SGL memory.
1439  *
1440  * @se_cmd: command descriptor to submit
1441  * @se_sess: associated se_sess for endpoint
1442  * @cdb: pointer to SCSI CDB
1443  * @sense: pointer to SCSI sense buffer
1444  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1445  * @data_length: fabric expected data transfer length
1446  * @task_addr: SAM task attribute
1447  * @data_dir: DMA data direction
1448  * @flags: flags for command submission from target_sc_flags_tables
1449  * @sgl: struct scatterlist memory for unidirectional mapping
1450  * @sgl_count: scatterlist count for unidirectional mapping
1451  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1452  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1453  * @sgl_prot: struct scatterlist memory protection information
1454  * @sgl_prot_count: scatterlist count for protection information
1455  *
1456  * Task tags are supported if the caller has set @se_cmd->tag.
1457  *
1458  * Returns non zero to signal active I/O shutdown failure.  All other
1459  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1460  * but still return zero here.
1461  *
1462  * This may only be called from process context, and also currently
1463  * assumes internal allocation of fabric payload buffer by target-core.
1464  */
1465 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1466                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1467                 u32 data_length, int task_attr, int data_dir, int flags,
1468                 struct scatterlist *sgl, u32 sgl_count,
1469                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1470                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1471 {
1472         struct se_portal_group *se_tpg;
1473         sense_reason_t rc;
1474         int ret;
1475
1476         se_tpg = se_sess->se_tpg;
1477         BUG_ON(!se_tpg);
1478         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1479         BUG_ON(in_interrupt());
1480         /*
1481          * Initialize se_cmd for target operation.  From this point
1482          * exceptions are handled by sending exception status via
1483          * target_core_fabric_ops->queue_status() callback
1484          */
1485         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1486                                 data_length, data_dir, task_attr, sense);
1487
1488         if (flags & TARGET_SCF_USE_CPUID)
1489                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1490         else
1491                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1492
1493         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1494                 se_cmd->unknown_data_length = 1;
1495         /*
1496          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1497          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1498          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1499          * kref_put() to happen during fabric packet acknowledgement.
1500          */
1501         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1502         if (ret)
1503                 return ret;
1504         /*
1505          * Signal bidirectional data payloads to target-core
1506          */
1507         if (flags & TARGET_SCF_BIDI_OP)
1508                 se_cmd->se_cmd_flags |= SCF_BIDI;
1509         /*
1510          * Locate se_lun pointer and attach it to struct se_cmd
1511          */
1512         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1513         if (rc) {
1514                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1515                 target_put_sess_cmd(se_cmd);
1516                 return 0;
1517         }
1518
1519         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1520         if (rc != 0) {
1521                 transport_generic_request_failure(se_cmd, rc);
1522                 return 0;
1523         }
1524
1525         /*
1526          * Save pointers for SGLs containing protection information,
1527          * if present.
1528          */
1529         if (sgl_prot_count) {
1530                 se_cmd->t_prot_sg = sgl_prot;
1531                 se_cmd->t_prot_nents = sgl_prot_count;
1532                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1533         }
1534
1535         /*
1536          * When a non zero sgl_count has been passed perform SGL passthrough
1537          * mapping for pre-allocated fabric memory instead of having target
1538          * core perform an internal SGL allocation..
1539          */
1540         if (sgl_count != 0) {
1541                 BUG_ON(!sgl);
1542
1543                 /*
1544                  * A work-around for tcm_loop as some userspace code via
1545                  * scsi-generic do not memset their associated read buffers,
1546                  * so go ahead and do that here for type non-data CDBs.  Also
1547                  * note that this is currently guaranteed to be a single SGL
1548                  * for this case by target core in target_setup_cmd_from_cdb()
1549                  * -> transport_generic_cmd_sequencer().
1550                  */
1551                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1552                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1553                         unsigned char *buf = NULL;
1554
1555                         if (sgl)
1556                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1557
1558                         if (buf) {
1559                                 memset(buf, 0, sgl->length);
1560                                 kunmap(sg_page(sgl));
1561                         }
1562                 }
1563
1564                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1565                                 sgl_bidi, sgl_bidi_count);
1566                 if (rc != 0) {
1567                         transport_generic_request_failure(se_cmd, rc);
1568                         return 0;
1569                 }
1570         }
1571
1572         /*
1573          * Check if we need to delay processing because of ALUA
1574          * Active/NonOptimized primary access state..
1575          */
1576         core_alua_check_nonop_delay(se_cmd);
1577
1578         transport_handle_cdb_direct(se_cmd);
1579         return 0;
1580 }
1581 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1582
1583 /*
1584  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1585  *
1586  * @se_cmd: command descriptor to submit
1587  * @se_sess: associated se_sess for endpoint
1588  * @cdb: pointer to SCSI CDB
1589  * @sense: pointer to SCSI sense buffer
1590  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1591  * @data_length: fabric expected data transfer length
1592  * @task_addr: SAM task attribute
1593  * @data_dir: DMA data direction
1594  * @flags: flags for command submission from target_sc_flags_tables
1595  *
1596  * Task tags are supported if the caller has set @se_cmd->tag.
1597  *
1598  * Returns non zero to signal active I/O shutdown failure.  All other
1599  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1600  * but still return zero here.
1601  *
1602  * This may only be called from process context, and also currently
1603  * assumes internal allocation of fabric payload buffer by target-core.
1604  *
1605  * It also assumes interal target core SGL memory allocation.
1606  */
1607 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1608                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1609                 u32 data_length, int task_attr, int data_dir, int flags)
1610 {
1611         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1612                         unpacked_lun, data_length, task_attr, data_dir,
1613                         flags, NULL, 0, NULL, 0, NULL, 0);
1614 }
1615 EXPORT_SYMBOL(target_submit_cmd);
1616
1617 static void target_complete_tmr_failure(struct work_struct *work)
1618 {
1619         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1620
1621         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1622         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1623
1624         transport_lun_remove_cmd(se_cmd);
1625         transport_cmd_check_stop_to_fabric(se_cmd);
1626 }
1627
1628 static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
1629                                        u64 *unpacked_lun)
1630 {
1631         struct se_cmd *se_cmd;
1632         unsigned long flags;
1633         bool ret = false;
1634
1635         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
1636         list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
1637                 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1638                         continue;
1639
1640                 if (se_cmd->tag == tag) {
1641                         *unpacked_lun = se_cmd->orig_fe_lun;
1642                         ret = true;
1643                         break;
1644                 }
1645         }
1646         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
1647
1648         return ret;
1649 }
1650
1651 /**
1652  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1653  *                     for TMR CDBs
1654  *
1655  * @se_cmd: command descriptor to submit
1656  * @se_sess: associated se_sess for endpoint
1657  * @sense: pointer to SCSI sense buffer
1658  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1659  * @fabric_context: fabric context for TMR req
1660  * @tm_type: Type of TM request
1661  * @gfp: gfp type for caller
1662  * @tag: referenced task tag for TMR_ABORT_TASK
1663  * @flags: submit cmd flags
1664  *
1665  * Callable from all contexts.
1666  **/
1667
1668 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1669                 unsigned char *sense, u64 unpacked_lun,
1670                 void *fabric_tmr_ptr, unsigned char tm_type,
1671                 gfp_t gfp, u64 tag, int flags)
1672 {
1673         struct se_portal_group *se_tpg;
1674         int ret;
1675
1676         se_tpg = se_sess->se_tpg;
1677         BUG_ON(!se_tpg);
1678
1679         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1680                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1681         /*
1682          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1683          * allocation failure.
1684          */
1685         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1686         if (ret < 0)
1687                 return -ENOMEM;
1688
1689         if (tm_type == TMR_ABORT_TASK)
1690                 se_cmd->se_tmr_req->ref_task_tag = tag;
1691
1692         /* See target_submit_cmd for commentary */
1693         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1694         if (ret) {
1695                 core_tmr_release_req(se_cmd->se_tmr_req);
1696                 return ret;
1697         }
1698         /*
1699          * If this is ABORT_TASK with no explicit fabric provided LUN,
1700          * go ahead and search active session tags for a match to figure
1701          * out unpacked_lun for the original se_cmd.
1702          */
1703         if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
1704                 if (!target_lookup_lun_from_tag(se_sess, tag, &unpacked_lun))
1705                         goto failure;
1706         }
1707
1708         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1709         if (ret)
1710                 goto failure;
1711
1712         transport_generic_handle_tmr(se_cmd);
1713         return 0;
1714
1715         /*
1716          * For callback during failure handling, push this work off
1717          * to process context with TMR_LUN_DOES_NOT_EXIST status.
1718          */
1719 failure:
1720         INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1721         schedule_work(&se_cmd->work);
1722         return 0;
1723 }
1724 EXPORT_SYMBOL(target_submit_tmr);
1725
1726 /*
1727  * Handle SAM-esque emulation for generic transport request failures.
1728  */
1729 void transport_generic_request_failure(struct se_cmd *cmd,
1730                 sense_reason_t sense_reason)
1731 {
1732         int ret = 0, post_ret = 0;
1733
1734         pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
1735                  sense_reason);
1736         target_show_cmd("-----[ ", cmd);
1737
1738         /*
1739          * For SAM Task Attribute emulation for failed struct se_cmd
1740          */
1741         transport_complete_task_attr(cmd);
1742
1743         /*
1744          * Handle special case for COMPARE_AND_WRITE failure, where the
1745          * callback is expected to drop the per device ->caw_sem.
1746          */
1747         if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1748              cmd->transport_complete_callback)
1749                 cmd->transport_complete_callback(cmd, false, &post_ret);
1750
1751         if (transport_check_aborted_status(cmd, 1))
1752                 return;
1753
1754         switch (sense_reason) {
1755         case TCM_NON_EXISTENT_LUN:
1756         case TCM_UNSUPPORTED_SCSI_OPCODE:
1757         case TCM_INVALID_CDB_FIELD:
1758         case TCM_INVALID_PARAMETER_LIST:
1759         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1760         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1761         case TCM_UNKNOWN_MODE_PAGE:
1762         case TCM_WRITE_PROTECTED:
1763         case TCM_ADDRESS_OUT_OF_RANGE:
1764         case TCM_CHECK_CONDITION_ABORT_CMD:
1765         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1766         case TCM_CHECK_CONDITION_NOT_READY:
1767         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1768         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1769         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1770         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1771         case TCM_TOO_MANY_TARGET_DESCS:
1772         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1773         case TCM_TOO_MANY_SEGMENT_DESCS:
1774         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1775                 break;
1776         case TCM_OUT_OF_RESOURCES:
1777                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1778                 break;
1779         case TCM_RESERVATION_CONFLICT:
1780                 /*
1781                  * No SENSE Data payload for this case, set SCSI Status
1782                  * and queue the response to $FABRIC_MOD.
1783                  *
1784                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1785                  */
1786                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1787                 /*
1788                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1789                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1790                  * CONFLICT STATUS.
1791                  *
1792                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1793                  */
1794                 if (cmd->se_sess &&
1795                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1796                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1797                                                cmd->orig_fe_lun, 0x2C,
1798                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1799                 }
1800                 trace_target_cmd_complete(cmd);
1801                 ret = cmd->se_tfo->queue_status(cmd);
1802                 if (ret)
1803                         goto queue_full;
1804                 goto check_stop;
1805         default:
1806                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1807                         cmd->t_task_cdb[0], sense_reason);
1808                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1809                 break;
1810         }
1811
1812         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1813         if (ret)
1814                 goto queue_full;
1815
1816 check_stop:
1817         transport_lun_remove_cmd(cmd);
1818         transport_cmd_check_stop_to_fabric(cmd);
1819         return;
1820
1821 queue_full:
1822         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1823 }
1824 EXPORT_SYMBOL(transport_generic_request_failure);
1825
1826 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1827 {
1828         sense_reason_t ret;
1829
1830         if (!cmd->execute_cmd) {
1831                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1832                 goto err;
1833         }
1834         if (do_checks) {
1835                 /*
1836                  * Check for an existing UNIT ATTENTION condition after
1837                  * target_handle_task_attr() has done SAM task attr
1838                  * checking, and possibly have already defered execution
1839                  * out to target_restart_delayed_cmds() context.
1840                  */
1841                 ret = target_scsi3_ua_check(cmd);
1842                 if (ret)
1843                         goto err;
1844
1845                 ret = target_alua_state_check(cmd);
1846                 if (ret)
1847                         goto err;
1848
1849                 ret = target_check_reservation(cmd);
1850                 if (ret) {
1851                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1852                         goto err;
1853                 }
1854         }
1855
1856         ret = cmd->execute_cmd(cmd);
1857         if (!ret)
1858                 return;
1859 err:
1860         spin_lock_irq(&cmd->t_state_lock);
1861         cmd->transport_state &= ~CMD_T_SENT;
1862         spin_unlock_irq(&cmd->t_state_lock);
1863
1864         transport_generic_request_failure(cmd, ret);
1865 }
1866
1867 static int target_write_prot_action(struct se_cmd *cmd)
1868 {
1869         u32 sectors;
1870         /*
1871          * Perform WRITE_INSERT of PI using software emulation when backend
1872          * device has PI enabled, if the transport has not already generated
1873          * PI using hardware WRITE_INSERT offload.
1874          */
1875         switch (cmd->prot_op) {
1876         case TARGET_PROT_DOUT_INSERT:
1877                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1878                         sbc_dif_generate(cmd);
1879                 break;
1880         case TARGET_PROT_DOUT_STRIP:
1881                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1882                         break;
1883
1884                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1885                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1886                                              sectors, 0, cmd->t_prot_sg, 0);
1887                 if (unlikely(cmd->pi_err)) {
1888                         spin_lock_irq(&cmd->t_state_lock);
1889                         cmd->transport_state &= ~CMD_T_SENT;
1890                         spin_unlock_irq(&cmd->t_state_lock);
1891                         transport_generic_request_failure(cmd, cmd->pi_err);
1892                         return -1;
1893                 }
1894                 break;
1895         default:
1896                 break;
1897         }
1898
1899         return 0;
1900 }
1901
1902 static bool target_handle_task_attr(struct se_cmd *cmd)
1903 {
1904         struct se_device *dev = cmd->se_dev;
1905
1906         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1907                 return false;
1908
1909         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1910
1911         /*
1912          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1913          * to allow the passed struct se_cmd list of tasks to the front of the list.
1914          */
1915         switch (cmd->sam_task_attr) {
1916         case TCM_HEAD_TAG:
1917                 atomic_inc_mb(&dev->non_ordered);
1918                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1919                          cmd->t_task_cdb[0]);
1920                 return false;
1921         case TCM_ORDERED_TAG:
1922                 atomic_inc_mb(&dev->delayed_cmd_count);
1923
1924                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1925                          cmd->t_task_cdb[0]);
1926                 break;
1927         default:
1928                 /*
1929                  * For SIMPLE and UNTAGGED Task Attribute commands
1930                  */
1931                 atomic_inc_mb(&dev->non_ordered);
1932
1933                 if (atomic_read(&dev->delayed_cmd_count) == 0)
1934                         return false;
1935                 break;
1936         }
1937
1938         if (cmd->sam_task_attr != TCM_ORDERED_TAG) {
1939                 atomic_inc_mb(&dev->delayed_cmd_count);
1940                 /*
1941                  * We will account for this when we dequeue from the delayed
1942                  * list.
1943                  */
1944                 atomic_dec_mb(&dev->non_ordered);
1945         }
1946
1947         spin_lock(&dev->delayed_cmd_lock);
1948         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1949         spin_unlock(&dev->delayed_cmd_lock);
1950
1951         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1952                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1953         /*
1954          * We may have no non ordered cmds when this function started or we
1955          * could have raced with the last simple/head cmd completing, so kick
1956          * the delayed handler here.
1957          */
1958         schedule_work(&dev->delayed_cmd_work);
1959         return true;
1960 }
1961
1962 static int __transport_check_aborted_status(struct se_cmd *, int);
1963
1964 void target_execute_cmd(struct se_cmd *cmd)
1965 {
1966         /*
1967          * Determine if frontend context caller is requesting the stopping of
1968          * this command for frontend exceptions.
1969          *
1970          * If the received CDB has aleady been aborted stop processing it here.
1971          */
1972         spin_lock_irq(&cmd->t_state_lock);
1973         if (__transport_check_aborted_status(cmd, 1)) {
1974                 spin_unlock_irq(&cmd->t_state_lock);
1975                 return;
1976         }
1977         if (cmd->transport_state & CMD_T_STOP) {
1978                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1979                         __func__, __LINE__, cmd->tag);
1980
1981                 spin_unlock_irq(&cmd->t_state_lock);
1982                 complete_all(&cmd->t_transport_stop_comp);
1983                 return;
1984         }
1985
1986         cmd->t_state = TRANSPORT_PROCESSING;
1987         cmd->transport_state &= ~CMD_T_PRE_EXECUTE;
1988         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
1989         spin_unlock_irq(&cmd->t_state_lock);
1990
1991         if (target_write_prot_action(cmd))
1992                 return;
1993
1994         if (target_handle_task_attr(cmd)) {
1995                 spin_lock_irq(&cmd->t_state_lock);
1996                 cmd->transport_state &= ~CMD_T_SENT;
1997                 spin_unlock_irq(&cmd->t_state_lock);
1998                 return;
1999         }
2000
2001         __target_execute_cmd(cmd, true);
2002 }
2003 EXPORT_SYMBOL(target_execute_cmd);
2004
2005 /*
2006  * Process all commands up to the last received ORDERED task attribute which
2007  * requires another blocking boundary
2008  */
2009 void target_do_delayed_work(struct work_struct *work)
2010 {
2011         struct se_device *dev = container_of(work, struct se_device,
2012                                              delayed_cmd_work);
2013
2014         spin_lock(&dev->delayed_cmd_lock);
2015         while (!dev->ordered_sync_in_progress) {
2016                 struct se_cmd *cmd;
2017
2018                 if (list_empty(&dev->delayed_cmd_list))
2019                         break;
2020
2021                 cmd = list_entry(dev->delayed_cmd_list.next,
2022                                  struct se_cmd, se_delayed_node);
2023
2024                 if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2025                         /*
2026                          * Check if we started with:
2027                          * [ordered] [simple] [ordered]
2028                          * and we are now at the last ordered so we have to wait
2029                          * for the simple cmd.
2030                          */
2031                         if (atomic_read(&dev->non_ordered) > 0)
2032                                 break;
2033
2034                         dev->ordered_sync_in_progress = true;
2035                 }
2036
2037                 list_del(&cmd->se_delayed_node);
2038                 atomic_dec_mb(&dev->delayed_cmd_count);
2039                 spin_unlock(&dev->delayed_cmd_lock);
2040
2041                 if (cmd->sam_task_attr != TCM_ORDERED_TAG)
2042                         atomic_inc_mb(&dev->non_ordered);
2043
2044                 cmd->transport_state |= CMD_T_SENT;
2045
2046                 __target_execute_cmd(cmd, true);
2047
2048                 spin_lock(&dev->delayed_cmd_lock);
2049         }
2050         spin_unlock(&dev->delayed_cmd_lock);
2051 }
2052
2053 /*
2054  * Called from I/O completion to determine which dormant/delayed
2055  * and ordered cmds need to have their tasks added to the execution queue.
2056  */
2057 static void transport_complete_task_attr(struct se_cmd *cmd)
2058 {
2059         struct se_device *dev = cmd->se_dev;
2060
2061         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2062                 return;
2063
2064         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2065                 goto restart;
2066
2067         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2068                 atomic_dec_mb(&dev->non_ordered);
2069                 dev->dev_cur_ordered_id++;
2070         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2071                 atomic_dec_mb(&dev->non_ordered);
2072                 dev->dev_cur_ordered_id++;
2073                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2074                          dev->dev_cur_ordered_id);
2075         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2076                 spin_lock(&dev->delayed_cmd_lock);
2077                 dev->ordered_sync_in_progress = false;
2078                 spin_unlock(&dev->delayed_cmd_lock);
2079
2080                 dev->dev_cur_ordered_id++;
2081                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2082                          dev->dev_cur_ordered_id);
2083         }
2084         cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2085
2086 restart:
2087         if (atomic_read(&dev->delayed_cmd_count) > 0)
2088                 schedule_work(&dev->delayed_cmd_work);
2089 }
2090
2091 static void transport_complete_qf(struct se_cmd *cmd)
2092 {
2093         int ret = 0;
2094
2095         transport_complete_task_attr(cmd);
2096         /*
2097          * If a fabric driver ->write_pending() or ->queue_data_in() callback
2098          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2099          * the same callbacks should not be retried.  Return CHECK_CONDITION
2100          * if a scsi_status is not already set.
2101          *
2102          * If a fabric driver ->queue_status() has returned non zero, always
2103          * keep retrying no matter what..
2104          */
2105         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2106                 if (cmd->scsi_status)
2107                         goto queue_status;
2108
2109                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2110                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2111                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2112                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2113                 goto queue_status;
2114         }
2115
2116         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2117                 goto queue_status;
2118
2119         switch (cmd->data_direction) {
2120         case DMA_FROM_DEVICE:
2121                 if (cmd->scsi_status)
2122                         goto queue_status;
2123
2124                 trace_target_cmd_complete(cmd);
2125                 ret = cmd->se_tfo->queue_data_in(cmd);
2126                 break;
2127         case DMA_TO_DEVICE:
2128                 if (cmd->se_cmd_flags & SCF_BIDI) {
2129                         ret = cmd->se_tfo->queue_data_in(cmd);
2130                         break;
2131                 }
2132                 /* Fall through for DMA_TO_DEVICE */
2133         case DMA_NONE:
2134 queue_status:
2135                 trace_target_cmd_complete(cmd);
2136                 ret = cmd->se_tfo->queue_status(cmd);
2137                 break;
2138         default:
2139                 break;
2140         }
2141
2142         if (ret < 0) {
2143                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2144                 return;
2145         }
2146         transport_lun_remove_cmd(cmd);
2147         transport_cmd_check_stop_to_fabric(cmd);
2148 }
2149
2150 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2151                                         int err, bool write_pending)
2152 {
2153         /*
2154          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2155          * ->queue_data_in() callbacks from new process context.
2156          *
2157          * Otherwise for other errors, transport_complete_qf() will send
2158          * CHECK_CONDITION via ->queue_status() instead of attempting to
2159          * retry associated fabric driver data-transfer callbacks.
2160          */
2161         if (err == -EAGAIN || err == -ENOMEM) {
2162                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2163                                                  TRANSPORT_COMPLETE_QF_OK;
2164         } else {
2165                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2166                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2167         }
2168
2169         spin_lock_irq(&dev->qf_cmd_lock);
2170         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2171         atomic_inc_mb(&dev->dev_qf_count);
2172         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2173
2174         schedule_work(&cmd->se_dev->qf_work_queue);
2175 }
2176
2177 static bool target_read_prot_action(struct se_cmd *cmd)
2178 {
2179         switch (cmd->prot_op) {
2180         case TARGET_PROT_DIN_STRIP:
2181                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2182                         u32 sectors = cmd->data_length >>
2183                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2184
2185                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2186                                                      sectors, 0, cmd->t_prot_sg,
2187                                                      0);
2188                         if (cmd->pi_err)
2189                                 return true;
2190                 }
2191                 break;
2192         case TARGET_PROT_DIN_INSERT:
2193                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2194                         break;
2195
2196                 sbc_dif_generate(cmd);
2197                 break;
2198         default:
2199                 break;
2200         }
2201
2202         return false;
2203 }
2204
2205 static void target_complete_ok_work(struct work_struct *work)
2206 {
2207         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2208         int ret;
2209
2210         /*
2211          * Check if we need to move delayed/dormant tasks from cmds on the
2212          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2213          * Attribute.
2214          */
2215         transport_complete_task_attr(cmd);
2216
2217         /*
2218          * Check to schedule QUEUE_FULL work, or execute an existing
2219          * cmd->transport_qf_callback()
2220          */
2221         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2222                 schedule_work(&cmd->se_dev->qf_work_queue);
2223
2224         /*
2225          * Check if we need to send a sense buffer from
2226          * the struct se_cmd in question.
2227          */
2228         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2229                 WARN_ON(!cmd->scsi_status);
2230                 ret = transport_send_check_condition_and_sense(
2231                                         cmd, 0, 1);
2232                 if (ret)
2233                         goto queue_full;
2234
2235                 transport_lun_remove_cmd(cmd);
2236                 transport_cmd_check_stop_to_fabric(cmd);
2237                 return;
2238         }
2239         /*
2240          * Check for a callback, used by amongst other things
2241          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2242          */
2243         if (cmd->transport_complete_callback) {
2244                 sense_reason_t rc;
2245                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2246                 bool zero_dl = !(cmd->data_length);
2247                 int post_ret = 0;
2248
2249                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2250                 if (!rc && !post_ret) {
2251                         if (caw && zero_dl)
2252                                 goto queue_rsp;
2253
2254                         return;
2255                 } else if (rc) {
2256                         ret = transport_send_check_condition_and_sense(cmd,
2257                                                 rc, 0);
2258                         if (ret)
2259                                 goto queue_full;
2260
2261                         transport_lun_remove_cmd(cmd);
2262                         transport_cmd_check_stop_to_fabric(cmd);
2263                         return;
2264                 }
2265         }
2266
2267 queue_rsp:
2268         switch (cmd->data_direction) {
2269         case DMA_FROM_DEVICE:
2270                 if (cmd->scsi_status)
2271                         goto queue_status;
2272
2273                 atomic_long_add(cmd->data_length,
2274                                 &cmd->se_lun->lun_stats.tx_data_octets);
2275                 /*
2276                  * Perform READ_STRIP of PI using software emulation when
2277                  * backend had PI enabled, if the transport will not be
2278                  * performing hardware READ_STRIP offload.
2279                  */
2280                 if (target_read_prot_action(cmd)) {
2281                         ret = transport_send_check_condition_and_sense(cmd,
2282                                                 cmd->pi_err, 0);
2283                         if (ret)
2284                                 goto queue_full;
2285
2286                         transport_lun_remove_cmd(cmd);
2287                         transport_cmd_check_stop_to_fabric(cmd);
2288                         return;
2289                 }
2290
2291                 trace_target_cmd_complete(cmd);
2292                 ret = cmd->se_tfo->queue_data_in(cmd);
2293                 if (ret)
2294                         goto queue_full;
2295                 break;
2296         case DMA_TO_DEVICE:
2297                 atomic_long_add(cmd->data_length,
2298                                 &cmd->se_lun->lun_stats.rx_data_octets);
2299                 /*
2300                  * Check if we need to send READ payload for BIDI-COMMAND
2301                  */
2302                 if (cmd->se_cmd_flags & SCF_BIDI) {
2303                         atomic_long_add(cmd->data_length,
2304                                         &cmd->se_lun->lun_stats.tx_data_octets);
2305                         ret = cmd->se_tfo->queue_data_in(cmd);
2306                         if (ret)
2307                                 goto queue_full;
2308                         break;
2309                 }
2310                 /* Fall through for DMA_TO_DEVICE */
2311         case DMA_NONE:
2312 queue_status:
2313                 trace_target_cmd_complete(cmd);
2314                 ret = cmd->se_tfo->queue_status(cmd);
2315                 if (ret)
2316                         goto queue_full;
2317                 break;
2318         default:
2319                 break;
2320         }
2321
2322         transport_lun_remove_cmd(cmd);
2323         transport_cmd_check_stop_to_fabric(cmd);
2324         return;
2325
2326 queue_full:
2327         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2328                 " data_direction: %d\n", cmd, cmd->data_direction);
2329
2330         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2331 }
2332
2333 void target_free_sgl(struct scatterlist *sgl, int nents)
2334 {
2335         struct scatterlist *sg;
2336         int count;
2337
2338         for_each_sg(sgl, sg, nents, count)
2339                 __free_page(sg_page(sg));
2340
2341         kfree(sgl);
2342 }
2343 EXPORT_SYMBOL(target_free_sgl);
2344
2345 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2346 {
2347         /*
2348          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2349          * emulation, and free + reset pointers if necessary..
2350          */
2351         if (!cmd->t_data_sg_orig)
2352                 return;
2353
2354         kfree(cmd->t_data_sg);
2355         cmd->t_data_sg = cmd->t_data_sg_orig;
2356         cmd->t_data_sg_orig = NULL;
2357         cmd->t_data_nents = cmd->t_data_nents_orig;
2358         cmd->t_data_nents_orig = 0;
2359 }
2360
2361 static inline void transport_free_pages(struct se_cmd *cmd)
2362 {
2363         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2364                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2365                 cmd->t_prot_sg = NULL;
2366                 cmd->t_prot_nents = 0;
2367         }
2368
2369         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2370                 /*
2371                  * Release special case READ buffer payload required for
2372                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2373                  */
2374                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2375                         target_free_sgl(cmd->t_bidi_data_sg,
2376                                            cmd->t_bidi_data_nents);
2377                         cmd->t_bidi_data_sg = NULL;
2378                         cmd->t_bidi_data_nents = 0;
2379                 }
2380                 transport_reset_sgl_orig(cmd);
2381                 return;
2382         }
2383         transport_reset_sgl_orig(cmd);
2384
2385         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2386         cmd->t_data_sg = NULL;
2387         cmd->t_data_nents = 0;
2388
2389         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2390         cmd->t_bidi_data_sg = NULL;
2391         cmd->t_bidi_data_nents = 0;
2392 }
2393
2394 /**
2395  * transport_put_cmd - release a reference to a command
2396  * @cmd:       command to release
2397  *
2398  * This routine releases our reference to the command and frees it if possible.
2399  */
2400 static int transport_put_cmd(struct se_cmd *cmd)
2401 {
2402         BUG_ON(!cmd->se_tfo);
2403         /*
2404          * If this cmd has been setup with target_get_sess_cmd(), drop
2405          * the kref and call ->release_cmd() in kref callback.
2406          */
2407         return target_put_sess_cmd(cmd);
2408 }
2409
2410 void *transport_kmap_data_sg(struct se_cmd *cmd)
2411 {
2412         struct scatterlist *sg = cmd->t_data_sg;
2413         struct page **pages;
2414         int i;
2415
2416         /*
2417          * We need to take into account a possible offset here for fabrics like
2418          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2419          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2420          */
2421         if (!cmd->t_data_nents)
2422                 return NULL;
2423
2424         BUG_ON(!sg);
2425         if (cmd->t_data_nents == 1)
2426                 return kmap(sg_page(sg)) + sg->offset;
2427
2428         /* >1 page. use vmap */
2429         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2430         if (!pages)
2431                 return NULL;
2432
2433         /* convert sg[] to pages[] */
2434         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2435                 pages[i] = sg_page(sg);
2436         }
2437
2438         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2439         kfree(pages);
2440         if (!cmd->t_data_vmap)
2441                 return NULL;
2442
2443         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2444 }
2445 EXPORT_SYMBOL(transport_kmap_data_sg);
2446
2447 void transport_kunmap_data_sg(struct se_cmd *cmd)
2448 {
2449         if (!cmd->t_data_nents) {
2450                 return;
2451         } else if (cmd->t_data_nents == 1) {
2452                 kunmap(sg_page(cmd->t_data_sg));
2453                 return;
2454         }
2455
2456         vunmap(cmd->t_data_vmap);
2457         cmd->t_data_vmap = NULL;
2458 }
2459 EXPORT_SYMBOL(transport_kunmap_data_sg);
2460
2461 int
2462 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2463                  bool zero_page, bool chainable)
2464 {
2465         struct scatterlist *sg;
2466         struct page *page;
2467         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2468         unsigned int nalloc, nent;
2469         int i = 0;
2470
2471         nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2472         if (chainable)
2473                 nalloc++;
2474         sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2475         if (!sg)
2476                 return -ENOMEM;
2477
2478         sg_init_table(sg, nalloc);
2479
2480         while (length) {
2481                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2482                 page = alloc_page(GFP_KERNEL | zero_flag);
2483                 if (!page)
2484                         goto out;
2485
2486                 sg_set_page(&sg[i], page, page_len, 0);
2487                 length -= page_len;
2488                 i++;
2489         }
2490         *sgl = sg;
2491         *nents = nent;
2492         return 0;
2493
2494 out:
2495         while (i > 0) {
2496                 i--;
2497                 __free_page(sg_page(&sg[i]));
2498         }
2499         kfree(sg);
2500         return -ENOMEM;
2501 }
2502 EXPORT_SYMBOL(target_alloc_sgl);
2503
2504 /*
2505  * Allocate any required resources to execute the command.  For writes we
2506  * might not have the payload yet, so notify the fabric via a call to
2507  * ->write_pending instead. Otherwise place it on the execution queue.
2508  */
2509 sense_reason_t
2510 transport_generic_new_cmd(struct se_cmd *cmd)
2511 {
2512         unsigned long flags;
2513         int ret = 0;
2514         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2515
2516         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2517             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2518                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2519                                        cmd->prot_length, true, false);
2520                 if (ret < 0)
2521                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2522         }
2523
2524         /*
2525          * Determine is the TCM fabric module has already allocated physical
2526          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2527          * beforehand.
2528          */
2529         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2530             cmd->data_length) {
2531
2532                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2533                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2534                         u32 bidi_length;
2535
2536                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2537                                 bidi_length = cmd->t_task_nolb *
2538                                               cmd->se_dev->dev_attrib.block_size;
2539                         else
2540                                 bidi_length = cmd->data_length;
2541
2542                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2543                                                &cmd->t_bidi_data_nents,
2544                                                bidi_length, zero_flag, false);
2545                         if (ret < 0)
2546                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2547                 }
2548
2549                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2550                                        cmd->data_length, zero_flag, false);
2551                 if (ret < 0)
2552                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2553         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2554                     cmd->data_length) {
2555                 /*
2556                  * Special case for COMPARE_AND_WRITE with fabrics
2557                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2558                  */
2559                 u32 caw_length = cmd->t_task_nolb *
2560                                  cmd->se_dev->dev_attrib.block_size;
2561
2562                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2563                                        &cmd->t_bidi_data_nents,
2564                                        caw_length, zero_flag, false);
2565                 if (ret < 0)
2566                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2567         }
2568         /*
2569          * If this command is not a write we can execute it right here,
2570          * for write buffers we need to notify the fabric driver first
2571          * and let it call back once the write buffers are ready.
2572          */
2573         target_add_to_state_list(cmd);
2574         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2575                 target_execute_cmd(cmd);
2576                 return 0;
2577         }
2578
2579         spin_lock_irqsave(&cmd->t_state_lock, flags);
2580         cmd->t_state = TRANSPORT_WRITE_PENDING;
2581         /*
2582          * Determine if frontend context caller is requesting the stopping of
2583          * this command for frontend exceptions.
2584          */
2585         if (cmd->transport_state & CMD_T_STOP) {
2586                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2587                          __func__, __LINE__, cmd->tag);
2588
2589                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2590
2591                 complete_all(&cmd->t_transport_stop_comp);
2592                 return 0;
2593         }
2594         cmd->transport_state &= ~CMD_T_ACTIVE;
2595         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2596
2597         ret = cmd->se_tfo->write_pending(cmd);
2598         if (ret)
2599                 goto queue_full;
2600
2601         return 0;
2602
2603 queue_full:
2604         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2605         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2606         return 0;
2607 }
2608 EXPORT_SYMBOL(transport_generic_new_cmd);
2609
2610 static void transport_write_pending_qf(struct se_cmd *cmd)
2611 {
2612         unsigned long flags;
2613         int ret;
2614         bool stop;
2615
2616         spin_lock_irqsave(&cmd->t_state_lock, flags);
2617         stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2618         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2619
2620         if (stop) {
2621                 pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2622                         __func__, __LINE__, cmd->tag);
2623                 complete_all(&cmd->t_transport_stop_comp);
2624                 return;
2625         }
2626
2627         ret = cmd->se_tfo->write_pending(cmd);
2628         if (ret) {
2629                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2630                          cmd);
2631                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2632         }
2633 }
2634
2635 static bool
2636 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2637                            unsigned long *flags);
2638
2639 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2640 {
2641         unsigned long flags;
2642
2643         spin_lock_irqsave(&cmd->t_state_lock, flags);
2644         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2645         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2646 }
2647
2648 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2649 {
2650         int ret = 0;
2651         bool aborted = false, tas = false;
2652
2653         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2654                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2655                         target_wait_free_cmd(cmd, &aborted, &tas);
2656
2657                 if (!aborted || tas)
2658                         ret = transport_put_cmd(cmd);
2659         } else {
2660                 if (wait_for_tasks)
2661                         target_wait_free_cmd(cmd, &aborted, &tas);
2662                 /*
2663                  * Handle WRITE failure case where transport_generic_new_cmd()
2664                  * has already added se_cmd to state_list, but fabric has
2665                  * failed command before I/O submission.
2666                  */
2667                 if (cmd->state_active)
2668                         target_remove_from_state_list(cmd);
2669
2670                 if (cmd->se_lun)
2671                         transport_lun_remove_cmd(cmd);
2672
2673                 if (!aborted || tas)
2674                         ret = transport_put_cmd(cmd);
2675         }
2676         /*
2677          * If the task has been internally aborted due to TMR ABORT_TASK
2678          * or LUN_RESET, target_core_tmr.c is responsible for performing
2679          * the remaining calls to target_put_sess_cmd(), and not the
2680          * callers of this function.
2681          */
2682         if (aborted) {
2683                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2684                 wait_for_completion(&cmd->cmd_wait_comp);
2685                 cmd->se_tfo->release_cmd(cmd);
2686                 ret = 1;
2687         }
2688         return ret;
2689 }
2690 EXPORT_SYMBOL(transport_generic_free_cmd);
2691
2692 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2693  * @se_cmd:     command descriptor to add
2694  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2695  */
2696 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2697 {
2698         struct se_session *se_sess = se_cmd->se_sess;
2699         unsigned long flags;
2700         int ret = 0;
2701
2702         /*
2703          * Add a second kref if the fabric caller is expecting to handle
2704          * fabric acknowledgement that requires two target_put_sess_cmd()
2705          * invocations before se_cmd descriptor release.
2706          */
2707         if (ack_kref) {
2708                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2709                         return -EINVAL;
2710
2711                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2712         }
2713
2714         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2715         if (se_sess->sess_tearing_down) {
2716                 ret = -ESHUTDOWN;
2717                 goto out;
2718         }
2719         se_cmd->transport_state |= CMD_T_PRE_EXECUTE;
2720         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2721 out:
2722         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2723
2724         if (ret && ack_kref)
2725                 target_put_sess_cmd(se_cmd);
2726
2727         return ret;
2728 }
2729 EXPORT_SYMBOL(target_get_sess_cmd);
2730
2731 static void target_free_cmd_mem(struct se_cmd *cmd)
2732 {
2733         transport_free_pages(cmd);
2734
2735         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2736                 core_tmr_release_req(cmd->se_tmr_req);
2737         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2738                 kfree(cmd->t_task_cdb);
2739 }
2740
2741 static void target_release_cmd_kref(struct kref *kref)
2742 {
2743         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2744         struct se_session *se_sess = se_cmd->se_sess;
2745         unsigned long flags;
2746         bool fabric_stop;
2747
2748         if (se_sess) {
2749                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2750
2751                 spin_lock(&se_cmd->t_state_lock);
2752                 fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2753                               (se_cmd->transport_state & CMD_T_ABORTED);
2754                 spin_unlock(&se_cmd->t_state_lock);
2755
2756                 if (se_cmd->cmd_wait_set || fabric_stop) {
2757                         list_del_init(&se_cmd->se_cmd_list);
2758                         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2759                         target_free_cmd_mem(se_cmd);
2760                         complete(&se_cmd->cmd_wait_comp);
2761                         return;
2762                 }
2763                 list_del_init(&se_cmd->se_cmd_list);
2764                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2765         }
2766
2767         target_free_cmd_mem(se_cmd);
2768         se_cmd->se_tfo->release_cmd(se_cmd);
2769 }
2770
2771 /**
2772  * target_put_sess_cmd - decrease the command reference count
2773  * @se_cmd:     command to drop a reference from
2774  *
2775  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2776  * refcount to drop to zero. Returns zero otherwise.
2777  */
2778 int target_put_sess_cmd(struct se_cmd *se_cmd)
2779 {
2780         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2781 }
2782 EXPORT_SYMBOL(target_put_sess_cmd);
2783
2784 static const char *data_dir_name(enum dma_data_direction d)
2785 {
2786         switch (d) {
2787         case DMA_BIDIRECTIONAL: return "BIDI";
2788         case DMA_TO_DEVICE:     return "WRITE";
2789         case DMA_FROM_DEVICE:   return "READ";
2790         case DMA_NONE:          return "NONE";
2791         }
2792
2793         return "(?)";
2794 }
2795
2796 static const char *cmd_state_name(enum transport_state_table t)
2797 {
2798         switch (t) {
2799         case TRANSPORT_NO_STATE:        return "NO_STATE";
2800         case TRANSPORT_NEW_CMD:         return "NEW_CMD";
2801         case TRANSPORT_WRITE_PENDING:   return "WRITE_PENDING";
2802         case TRANSPORT_PROCESSING:      return "PROCESSING";
2803         case TRANSPORT_COMPLETE:        return "COMPLETE";
2804         case TRANSPORT_ISTATE_PROCESSING:
2805                                         return "ISTATE_PROCESSING";
2806         case TRANSPORT_COMPLETE_QF_WP:  return "COMPLETE_QF_WP";
2807         case TRANSPORT_COMPLETE_QF_OK:  return "COMPLETE_QF_OK";
2808         case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
2809         }
2810
2811         return "(?)";
2812 }
2813
2814 static void target_append_str(char **str, const char *txt)
2815 {
2816         char *prev = *str;
2817
2818         *str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
2819                 kstrdup(txt, GFP_ATOMIC);
2820         kfree(prev);
2821 }
2822
2823 /*
2824  * Convert a transport state bitmask into a string. The caller is
2825  * responsible for freeing the returned pointer.
2826  */
2827 static char *target_ts_to_str(u32 ts)
2828 {
2829         char *str = NULL;
2830
2831         if (ts & CMD_T_ABORTED)
2832                 target_append_str(&str, "aborted");
2833         if (ts & CMD_T_ACTIVE)
2834                 target_append_str(&str, "active");
2835         if (ts & CMD_T_COMPLETE)
2836                 target_append_str(&str, "complete");
2837         if (ts & CMD_T_SENT)
2838                 target_append_str(&str, "sent");
2839         if (ts & CMD_T_STOP)
2840                 target_append_str(&str, "stop");
2841         if (ts & CMD_T_FABRIC_STOP)
2842                 target_append_str(&str, "fabric_stop");
2843
2844         return str;
2845 }
2846
2847 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
2848 {
2849         switch (tmf) {
2850         case TMR_ABORT_TASK:            return "ABORT_TASK";
2851         case TMR_ABORT_TASK_SET:        return "ABORT_TASK_SET";
2852         case TMR_CLEAR_ACA:             return "CLEAR_ACA";
2853         case TMR_CLEAR_TASK_SET:        return "CLEAR_TASK_SET";
2854         case TMR_LUN_RESET:             return "LUN_RESET";
2855         case TMR_TARGET_WARM_RESET:     return "TARGET_WARM_RESET";
2856         case TMR_TARGET_COLD_RESET:     return "TARGET_COLD_RESET";
2857         case TMR_UNKNOWN:               break;
2858         }
2859         return "(?)";
2860 }
2861
2862 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
2863 {
2864         char *ts_str = target_ts_to_str(cmd->transport_state);
2865         const u8 *cdb = cmd->t_task_cdb;
2866         struct se_tmr_req *tmf = cmd->se_tmr_req;
2867
2868         if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2869                 pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
2870                          pfx, cdb[0], cdb[1], cmd->tag,
2871                          data_dir_name(cmd->data_direction),
2872                          cmd->se_tfo->get_cmd_state(cmd),
2873                          cmd_state_name(cmd->t_state), cmd->data_length,
2874                          kref_read(&cmd->cmd_kref), ts_str);
2875         } else {
2876                 pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
2877                          pfx, target_tmf_name(tmf->function), cmd->tag,
2878                          tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
2879                          cmd_state_name(cmd->t_state),
2880                          kref_read(&cmd->cmd_kref), ts_str);
2881         }
2882         kfree(ts_str);
2883 }
2884 EXPORT_SYMBOL(target_show_cmd);
2885
2886 /* target_sess_cmd_list_set_waiting - Flag all commands in
2887  *         sess_cmd_list to complete cmd_wait_comp.  Set
2888  *         sess_tearing_down so no more commands are queued.
2889  * @se_sess:    session to flag
2890  */
2891 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2892 {
2893         struct se_cmd *se_cmd, *tmp_cmd;
2894         unsigned long flags;
2895         int rc;
2896
2897         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2898         if (se_sess->sess_tearing_down) {
2899                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2900                 return;
2901         }
2902         se_sess->sess_tearing_down = 1;
2903         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2904
2905         list_for_each_entry_safe(se_cmd, tmp_cmd,
2906                                  &se_sess->sess_wait_list, se_cmd_list) {
2907                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2908                 if (rc) {
2909                         se_cmd->cmd_wait_set = 1;
2910                         spin_lock(&se_cmd->t_state_lock);
2911                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2912                         spin_unlock(&se_cmd->t_state_lock);
2913                 } else
2914                         list_del_init(&se_cmd->se_cmd_list);
2915         }
2916
2917         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2918 }
2919 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2920
2921 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2922  * @se_sess:    session to wait for active I/O
2923  */
2924 void target_wait_for_sess_cmds(struct se_session *se_sess)
2925 {
2926         struct se_cmd *se_cmd, *tmp_cmd;
2927         unsigned long flags;
2928         bool tas;
2929
2930         list_for_each_entry_safe(se_cmd, tmp_cmd,
2931                                 &se_sess->sess_wait_list, se_cmd_list) {
2932                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2933                         " %d\n", se_cmd, se_cmd->t_state,
2934                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2935
2936                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2937                 tas = (se_cmd->transport_state & CMD_T_TAS);
2938                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2939
2940                 if (!target_put_sess_cmd(se_cmd)) {
2941                         if (tas)
2942                                 target_put_sess_cmd(se_cmd);
2943                 }
2944
2945                 wait_for_completion(&se_cmd->cmd_wait_comp);
2946                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2947                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2948                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2949
2950                 se_cmd->se_tfo->release_cmd(se_cmd);
2951         }
2952
2953         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2954         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2955         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2956
2957 }
2958 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2959
2960 static void target_lun_confirm(struct percpu_ref *ref)
2961 {
2962         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2963
2964         complete(&lun->lun_ref_comp);
2965 }
2966
2967 void transport_clear_lun_ref(struct se_lun *lun)
2968 {
2969         /*
2970          * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2971          * the initial reference and schedule confirm kill to be
2972          * executed after one full RCU grace period has completed.
2973          */
2974         percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2975         /*
2976          * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2977          * to call target_lun_confirm after lun->lun_ref has been marked
2978          * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2979          * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2980          * fails for all new incoming I/O.
2981          */
2982         wait_for_completion(&lun->lun_ref_comp);
2983         /*
2984          * The second completion waits for percpu_ref_put_many() to
2985          * invoke ->release() after lun->lun_ref has switched to
2986          * atomic_t mode, and lun->lun_ref.count has reached zero.
2987          *
2988          * At this point all target-core lun->lun_ref references have
2989          * been dropped via transport_lun_remove_cmd(), and it's safe
2990          * to proceed with the remaining LUN shutdown.
2991          */
2992         wait_for_completion(&lun->lun_shutdown_comp);
2993 }
2994
2995 static bool
2996 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2997                            bool *aborted, bool *tas, unsigned long *flags)
2998         __releases(&cmd->t_state_lock)
2999         __acquires(&cmd->t_state_lock)
3000 {
3001         lockdep_assert_held(&cmd->t_state_lock);
3002
3003         if (fabric_stop)
3004                 cmd->transport_state |= CMD_T_FABRIC_STOP;
3005
3006         if (cmd->transport_state & CMD_T_ABORTED)
3007                 *aborted = true;
3008
3009         if (cmd->transport_state & CMD_T_TAS)
3010                 *tas = true;
3011
3012         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
3013             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3014                 return false;
3015
3016         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
3017             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3018                 return false;
3019
3020         if (!(cmd->transport_state & CMD_T_ACTIVE))
3021                 return false;
3022
3023         if (fabric_stop && *aborted)
3024                 return false;
3025
3026         cmd->transport_state |= CMD_T_STOP;
3027
3028         target_show_cmd("wait_for_tasks: Stopping ", cmd);
3029
3030         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
3031
3032         while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
3033                                             180 * HZ))
3034                 target_show_cmd("wait for tasks: ", cmd);
3035
3036         spin_lock_irqsave(&cmd->t_state_lock, *flags);
3037         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
3038
3039         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
3040                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
3041
3042         return true;
3043 }
3044
3045 /**
3046  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3047  * @cmd: command to wait on
3048  */
3049 bool transport_wait_for_tasks(struct se_cmd *cmd)
3050 {
3051         unsigned long flags;
3052         bool ret, aborted = false, tas = false;
3053
3054         spin_lock_irqsave(&cmd->t_state_lock, flags);
3055         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3056         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3057
3058         return ret;
3059 }
3060 EXPORT_SYMBOL(transport_wait_for_tasks);
3061
3062 struct sense_info {
3063         u8 key;
3064         u8 asc;
3065         u8 ascq;
3066         bool add_sector_info;
3067 };
3068
3069 static const struct sense_info sense_info_table[] = {
3070         [TCM_NO_SENSE] = {
3071                 .key = NOT_READY
3072         },
3073         [TCM_NON_EXISTENT_LUN] = {
3074                 .key = ILLEGAL_REQUEST,
3075                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3076         },
3077         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
3078                 .key = ILLEGAL_REQUEST,
3079                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3080         },
3081         [TCM_SECTOR_COUNT_TOO_MANY] = {
3082                 .key = ILLEGAL_REQUEST,
3083                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3084         },
3085         [TCM_UNKNOWN_MODE_PAGE] = {
3086                 .key = ILLEGAL_REQUEST,
3087                 .asc = 0x24, /* INVALID FIELD IN CDB */
3088         },
3089         [TCM_CHECK_CONDITION_ABORT_CMD] = {
3090                 .key = ABORTED_COMMAND,
3091                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3092                 .ascq = 0x03,
3093         },
3094         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
3095                 .key = ABORTED_COMMAND,
3096                 .asc = 0x0c, /* WRITE ERROR */
3097                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3098         },
3099         [TCM_INVALID_CDB_FIELD] = {
3100                 .key = ILLEGAL_REQUEST,
3101                 .asc = 0x24, /* INVALID FIELD IN CDB */
3102         },
3103         [TCM_INVALID_PARAMETER_LIST] = {
3104                 .key = ILLEGAL_REQUEST,
3105                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3106         },
3107         [TCM_TOO_MANY_TARGET_DESCS] = {
3108                 .key = ILLEGAL_REQUEST,
3109                 .asc = 0x26,
3110                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3111         },
3112         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3113                 .key = ILLEGAL_REQUEST,
3114                 .asc = 0x26,
3115                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3116         },
3117         [TCM_TOO_MANY_SEGMENT_DESCS] = {
3118                 .key = ILLEGAL_REQUEST,
3119                 .asc = 0x26,
3120                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3121         },
3122         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3123                 .key = ILLEGAL_REQUEST,
3124                 .asc = 0x26,
3125                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3126         },
3127         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3128                 .key = ILLEGAL_REQUEST,
3129                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3130         },
3131         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3132                 .key = ILLEGAL_REQUEST,
3133                 .asc = 0x0c, /* WRITE ERROR */
3134                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3135         },
3136         [TCM_SERVICE_CRC_ERROR] = {
3137                 .key = ABORTED_COMMAND,
3138                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3139                 .ascq = 0x05, /* N/A */
3140         },
3141         [TCM_SNACK_REJECTED] = {
3142                 .key = ABORTED_COMMAND,
3143                 .asc = 0x11, /* READ ERROR */
3144                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3145         },
3146         [TCM_WRITE_PROTECTED] = {
3147                 .key = DATA_PROTECT,
3148                 .asc = 0x27, /* WRITE PROTECTED */
3149         },
3150         [TCM_ADDRESS_OUT_OF_RANGE] = {
3151                 .key = ILLEGAL_REQUEST,
3152                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3153         },
3154         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3155                 .key = UNIT_ATTENTION,
3156         },
3157         [TCM_CHECK_CONDITION_NOT_READY] = {
3158                 .key = NOT_READY,
3159         },
3160         [TCM_MISCOMPARE_VERIFY] = {
3161                 .key = MISCOMPARE,
3162                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3163                 .ascq = 0x00,
3164         },
3165         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3166                 .key = ABORTED_COMMAND,
3167                 .asc = 0x10,
3168                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3169                 .add_sector_info = true,
3170         },
3171         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3172                 .key = ABORTED_COMMAND,
3173                 .asc = 0x10,
3174                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3175                 .add_sector_info = true,
3176         },
3177         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3178                 .key = ABORTED_COMMAND,
3179                 .asc = 0x10,
3180                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3181                 .add_sector_info = true,
3182         },
3183         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3184                 .key = COPY_ABORTED,
3185                 .asc = 0x0d,
3186                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3187
3188         },
3189         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3190                 /*
3191                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
3192                  * Solaris initiators.  Returning NOT READY instead means the
3193                  * operations will be retried a finite number of times and we
3194                  * can survive intermittent errors.
3195                  */
3196                 .key = NOT_READY,
3197                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3198         },
3199 };
3200
3201 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3202 {
3203         const struct sense_info *si;
3204         u8 *buffer = cmd->sense_buffer;
3205         int r = (__force int)reason;
3206         u8 asc, ascq;
3207         bool desc_format = target_sense_desc_format(cmd->se_dev);
3208
3209         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
3210                 si = &sense_info_table[r];
3211         else
3212                 si = &sense_info_table[(__force int)
3213                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3214
3215         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3216                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
3217                 WARN_ON_ONCE(asc == 0);
3218         } else if (si->asc == 0) {
3219                 WARN_ON_ONCE(cmd->scsi_asc == 0);
3220                 asc = cmd->scsi_asc;
3221                 ascq = cmd->scsi_ascq;
3222         } else {
3223                 asc = si->asc;
3224                 ascq = si->ascq;
3225         }
3226
3227         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
3228         if (si->add_sector_info)
3229                 return scsi_set_sense_information(buffer,
3230                                                   cmd->scsi_sense_length,
3231                                                   cmd->bad_sector);
3232
3233         return 0;
3234 }
3235
3236 int
3237 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3238                 sense_reason_t reason, int from_transport)
3239 {
3240         unsigned long flags;
3241
3242         spin_lock_irqsave(&cmd->t_state_lock, flags);
3243         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3244                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3245                 return 0;
3246         }
3247         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3248         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3249
3250         if (!from_transport) {
3251                 int rc;
3252
3253                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3254                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3255                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3256                 rc = translate_sense_reason(cmd, reason);
3257                 if (rc)
3258                         return rc;
3259         }
3260
3261         trace_target_cmd_complete(cmd);
3262         return cmd->se_tfo->queue_status(cmd);
3263 }
3264 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3265
3266 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3267         __releases(&cmd->t_state_lock)
3268         __acquires(&cmd->t_state_lock)
3269 {
3270         int ret;
3271
3272         assert_spin_locked(&cmd->t_state_lock);
3273         WARN_ON_ONCE(!irqs_disabled());
3274
3275         if (!(cmd->transport_state & CMD_T_ABORTED))
3276                 return 0;
3277         /*
3278          * If cmd has been aborted but either no status is to be sent or it has
3279          * already been sent, just return
3280          */
3281         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3282                 if (send_status)
3283                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3284                 return 1;
3285         }
3286
3287         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3288                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3289
3290         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3291         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3292         trace_target_cmd_complete(cmd);
3293
3294         spin_unlock_irq(&cmd->t_state_lock);
3295         ret = cmd->se_tfo->queue_status(cmd);
3296         if (ret)
3297                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3298         spin_lock_irq(&cmd->t_state_lock);
3299
3300         return 1;
3301 }
3302
3303 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3304 {
3305         int ret;
3306
3307         spin_lock_irq(&cmd->t_state_lock);
3308         ret = __transport_check_aborted_status(cmd, send_status);
3309         spin_unlock_irq(&cmd->t_state_lock);
3310
3311         return ret;
3312 }
3313 EXPORT_SYMBOL(transport_check_aborted_status);
3314
3315 void transport_send_task_abort(struct se_cmd *cmd)
3316 {
3317         unsigned long flags;
3318         int ret;
3319
3320         spin_lock_irqsave(&cmd->t_state_lock, flags);
3321         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3322                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3323                 return;
3324         }
3325         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3326
3327         /*
3328          * If there are still expected incoming fabric WRITEs, we wait
3329          * until until they have completed before sending a TASK_ABORTED
3330          * response.  This response with TASK_ABORTED status will be
3331          * queued back to fabric module by transport_check_aborted_status().
3332          */
3333         if (cmd->data_direction == DMA_TO_DEVICE) {
3334                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3335                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3336                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3337                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3338                                 goto send_abort;
3339                         }
3340                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3341                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3342                         return;
3343                 }
3344         }
3345 send_abort:
3346         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3347
3348         transport_lun_remove_cmd(cmd);
3349
3350         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3351                  cmd->t_task_cdb[0], cmd->tag);
3352
3353         trace_target_cmd_complete(cmd);
3354         ret = cmd->se_tfo->queue_status(cmd);
3355         if (ret)
3356                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3357 }
3358
3359 static void target_tmr_work(struct work_struct *work)
3360 {
3361         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3362         struct se_device *dev = cmd->se_dev;
3363         struct se_tmr_req *tmr = cmd->se_tmr_req;
3364         unsigned long flags;
3365         int ret;
3366
3367         spin_lock_irqsave(&cmd->t_state_lock, flags);
3368         if (cmd->transport_state & CMD_T_ABORTED) {
3369                 tmr->response = TMR_FUNCTION_REJECTED;
3370                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3371                 goto check_stop;
3372         }
3373         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3374
3375         switch (tmr->function) {
3376         case TMR_ABORT_TASK:
3377                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3378                 break;
3379         case TMR_ABORT_TASK_SET:
3380         case TMR_CLEAR_ACA:
3381         case TMR_CLEAR_TASK_SET:
3382                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3383                 break;
3384         case TMR_LUN_RESET:
3385                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3386                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3387                                          TMR_FUNCTION_REJECTED;
3388                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3389                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3390                                                cmd->orig_fe_lun, 0x29,
3391                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3392                 }
3393                 break;
3394         case TMR_TARGET_WARM_RESET:
3395                 tmr->response = TMR_FUNCTION_REJECTED;
3396                 break;
3397         case TMR_TARGET_COLD_RESET:
3398                 tmr->response = TMR_FUNCTION_REJECTED;
3399                 break;
3400         default:
3401                 pr_err("Uknown TMR function: 0x%02x.\n",
3402                                 tmr->function);
3403                 tmr->response = TMR_FUNCTION_REJECTED;
3404                 break;
3405         }
3406
3407         spin_lock_irqsave(&cmd->t_state_lock, flags);
3408         if (cmd->transport_state & CMD_T_ABORTED) {
3409                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3410                 goto check_stop;
3411         }
3412         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3413
3414         cmd->se_tfo->queue_tm_rsp(cmd);
3415
3416 check_stop:
3417         transport_lun_remove_cmd(cmd);
3418         transport_cmd_check_stop_to_fabric(cmd);
3419 }
3420
3421 int transport_generic_handle_tmr(
3422         struct se_cmd *cmd)
3423 {
3424         unsigned long flags;
3425         bool aborted = false;
3426
3427         spin_lock_irqsave(&cmd->t_state_lock, flags);
3428         if (cmd->transport_state & CMD_T_ABORTED) {
3429                 aborted = true;
3430         } else {
3431                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3432                 cmd->transport_state |= CMD_T_ACTIVE;
3433         }
3434         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3435
3436         if (aborted) {
3437                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3438                         "ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3439                         cmd->se_tmr_req->ref_task_tag, cmd->tag);
3440                 transport_lun_remove_cmd(cmd);
3441                 transport_cmd_check_stop_to_fabric(cmd);
3442                 return 0;
3443         }
3444
3445         INIT_WORK(&cmd->work, target_tmr_work);
3446         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3447         return 0;
3448 }
3449 EXPORT_SYMBOL(transport_generic_handle_tmr);
3450
3451 bool
3452 target_check_wce(struct se_device *dev)
3453 {
3454         bool wce = false;
3455
3456         if (dev->transport->get_write_cache)
3457                 wce = dev->transport->get_write_cache(dev);
3458         else if (dev->dev_attrib.emulate_write_cache > 0)
3459                 wce = true;
3460
3461         return wce;
3462 }
3463
3464 bool
3465 target_check_fua(struct se_device *dev)
3466 {
3467         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3468 }