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