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