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         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1710                 break;
1711         case TCM_OUT_OF_RESOURCES:
1712                 sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1713                 break;
1714         case TCM_RESERVATION_CONFLICT:
1715                 /*
1716                  * No SENSE Data payload for this case, set SCSI Status
1717                  * and queue the response to $FABRIC_MOD.
1718                  *
1719                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1720                  */
1721                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1722                 /*
1723                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1724                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1725                  * CONFLICT STATUS.
1726                  *
1727                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1728                  */
1729                 if (cmd->se_sess &&
1730                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1731                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1732                                                cmd->orig_fe_lun, 0x2C,
1733                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1734                 }
1735                 trace_target_cmd_complete(cmd);
1736                 ret = cmd->se_tfo->queue_status(cmd);
1737                 if (ret == -EAGAIN || ret == -ENOMEM)
1738                         goto queue_full;
1739                 goto check_stop;
1740         default:
1741                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1742                         cmd->t_task_cdb[0], sense_reason);
1743                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1744                 break;
1745         }
1746
1747         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1748         if (ret == -EAGAIN || ret == -ENOMEM)
1749                 goto queue_full;
1750
1751 check_stop:
1752         transport_lun_remove_cmd(cmd);
1753         transport_cmd_check_stop_to_fabric(cmd);
1754         return;
1755
1756 queue_full:
1757         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1758         transport_handle_queue_full(cmd, cmd->se_dev);
1759 }
1760 EXPORT_SYMBOL(transport_generic_request_failure);
1761
1762 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1763 {
1764         sense_reason_t ret;
1765
1766         if (!cmd->execute_cmd) {
1767                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1768                 goto err;
1769         }
1770         if (do_checks) {
1771                 /*
1772                  * Check for an existing UNIT ATTENTION condition after
1773                  * target_handle_task_attr() has done SAM task attr
1774                  * checking, and possibly have already defered execution
1775                  * out to target_restart_delayed_cmds() context.
1776                  */
1777                 ret = target_scsi3_ua_check(cmd);
1778                 if (ret)
1779                         goto err;
1780
1781                 ret = target_alua_state_check(cmd);
1782                 if (ret)
1783                         goto err;
1784
1785                 ret = target_check_reservation(cmd);
1786                 if (ret) {
1787                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1788                         goto err;
1789                 }
1790         }
1791
1792         ret = cmd->execute_cmd(cmd);
1793         if (!ret)
1794                 return;
1795 err:
1796         spin_lock_irq(&cmd->t_state_lock);
1797         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1798         spin_unlock_irq(&cmd->t_state_lock);
1799
1800         transport_generic_request_failure(cmd, ret);
1801 }
1802
1803 static int target_write_prot_action(struct se_cmd *cmd)
1804 {
1805         u32 sectors;
1806         /*
1807          * Perform WRITE_INSERT of PI using software emulation when backend
1808          * device has PI enabled, if the transport has not already generated
1809          * PI using hardware WRITE_INSERT offload.
1810          */
1811         switch (cmd->prot_op) {
1812         case TARGET_PROT_DOUT_INSERT:
1813                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1814                         sbc_dif_generate(cmd);
1815                 break;
1816         case TARGET_PROT_DOUT_STRIP:
1817                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1818                         break;
1819
1820                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1821                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1822                                              sectors, 0, cmd->t_prot_sg, 0);
1823                 if (unlikely(cmd->pi_err)) {
1824                         spin_lock_irq(&cmd->t_state_lock);
1825                         cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1826                         spin_unlock_irq(&cmd->t_state_lock);
1827                         transport_generic_request_failure(cmd, cmd->pi_err);
1828                         return -1;
1829                 }
1830                 break;
1831         default:
1832                 break;
1833         }
1834
1835         return 0;
1836 }
1837
1838 static bool target_handle_task_attr(struct se_cmd *cmd)
1839 {
1840         struct se_device *dev = cmd->se_dev;
1841
1842         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1843                 return false;
1844
1845         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1846
1847         /*
1848          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1849          * to allow the passed struct se_cmd list of tasks to the front of the list.
1850          */
1851         switch (cmd->sam_task_attr) {
1852         case TCM_HEAD_TAG:
1853                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1854                          cmd->t_task_cdb[0]);
1855                 return false;
1856         case TCM_ORDERED_TAG:
1857                 atomic_inc_mb(&dev->dev_ordered_sync);
1858
1859                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1860                          cmd->t_task_cdb[0]);
1861
1862                 /*
1863                  * Execute an ORDERED command if no other older commands
1864                  * exist that need to be completed first.
1865                  */
1866                 if (!atomic_read(&dev->simple_cmds))
1867                         return false;
1868                 break;
1869         default:
1870                 /*
1871                  * For SIMPLE and UNTAGGED Task Attribute commands
1872                  */
1873                 atomic_inc_mb(&dev->simple_cmds);
1874                 break;
1875         }
1876
1877         if (atomic_read(&dev->dev_ordered_sync) == 0)
1878                 return false;
1879
1880         spin_lock(&dev->delayed_cmd_lock);
1881         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1882         spin_unlock(&dev->delayed_cmd_lock);
1883
1884         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1885                 cmd->t_task_cdb[0], cmd->sam_task_attr);
1886         return true;
1887 }
1888
1889 static int __transport_check_aborted_status(struct se_cmd *, int);
1890
1891 void target_execute_cmd(struct se_cmd *cmd)
1892 {
1893         /*
1894          * Determine if frontend context caller is requesting the stopping of
1895          * this command for frontend exceptions.
1896          *
1897          * If the received CDB has aleady been aborted stop processing it here.
1898          */
1899         spin_lock_irq(&cmd->t_state_lock);
1900         if (__transport_check_aborted_status(cmd, 1)) {
1901                 spin_unlock_irq(&cmd->t_state_lock);
1902                 return;
1903         }
1904         if (cmd->transport_state & CMD_T_STOP) {
1905                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1906                         __func__, __LINE__, cmd->tag);
1907
1908                 spin_unlock_irq(&cmd->t_state_lock);
1909                 complete_all(&cmd->t_transport_stop_comp);
1910                 return;
1911         }
1912
1913         cmd->t_state = TRANSPORT_PROCESSING;
1914         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1915         spin_unlock_irq(&cmd->t_state_lock);
1916
1917         if (target_write_prot_action(cmd))
1918                 return;
1919
1920         if (target_handle_task_attr(cmd)) {
1921                 spin_lock_irq(&cmd->t_state_lock);
1922                 cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1923                 spin_unlock_irq(&cmd->t_state_lock);
1924                 return;
1925         }
1926
1927         __target_execute_cmd(cmd, true);
1928 }
1929 EXPORT_SYMBOL(target_execute_cmd);
1930
1931 /*
1932  * Process all commands up to the last received ORDERED task attribute which
1933  * requires another blocking boundary
1934  */
1935 static void target_restart_delayed_cmds(struct se_device *dev)
1936 {
1937         for (;;) {
1938                 struct se_cmd *cmd;
1939
1940                 spin_lock(&dev->delayed_cmd_lock);
1941                 if (list_empty(&dev->delayed_cmd_list)) {
1942                         spin_unlock(&dev->delayed_cmd_lock);
1943                         break;
1944                 }
1945
1946                 cmd = list_entry(dev->delayed_cmd_list.next,
1947                                  struct se_cmd, se_delayed_node);
1948                 list_del(&cmd->se_delayed_node);
1949                 spin_unlock(&dev->delayed_cmd_lock);
1950
1951                 __target_execute_cmd(cmd, true);
1952
1953                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1954                         break;
1955         }
1956 }
1957
1958 /*
1959  * Called from I/O completion to determine which dormant/delayed
1960  * and ordered cmds need to have their tasks added to the execution queue.
1961  */
1962 static void transport_complete_task_attr(struct se_cmd *cmd)
1963 {
1964         struct se_device *dev = cmd->se_dev;
1965
1966         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1967                 return;
1968
1969         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
1970                 goto restart;
1971
1972         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1973                 atomic_dec_mb(&dev->simple_cmds);
1974                 dev->dev_cur_ordered_id++;
1975                 pr_debug("Incremented dev->dev_cur_ordered_id: %u for SIMPLE\n",
1976                          dev->dev_cur_ordered_id);
1977         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1978                 dev->dev_cur_ordered_id++;
1979                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1980                          dev->dev_cur_ordered_id);
1981         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1982                 atomic_dec_mb(&dev->dev_ordered_sync);
1983
1984                 dev->dev_cur_ordered_id++;
1985                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1986                          dev->dev_cur_ordered_id);
1987         }
1988 restart:
1989         target_restart_delayed_cmds(dev);
1990 }
1991
1992 static void transport_complete_qf(struct se_cmd *cmd)
1993 {
1994         int ret = 0;
1995
1996         transport_complete_task_attr(cmd);
1997
1998         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1999                 trace_target_cmd_complete(cmd);
2000                 ret = cmd->se_tfo->queue_status(cmd);
2001                 goto out;
2002         }
2003
2004         switch (cmd->data_direction) {
2005         case DMA_FROM_DEVICE:
2006                 if (cmd->scsi_status)
2007                         goto queue_status;
2008
2009                 trace_target_cmd_complete(cmd);
2010                 ret = cmd->se_tfo->queue_data_in(cmd);
2011                 break;
2012         case DMA_TO_DEVICE:
2013                 if (cmd->se_cmd_flags & SCF_BIDI) {
2014                         ret = cmd->se_tfo->queue_data_in(cmd);
2015                         break;
2016                 }
2017                 /* Fall through for DMA_TO_DEVICE */
2018         case DMA_NONE:
2019 queue_status:
2020                 trace_target_cmd_complete(cmd);
2021                 ret = cmd->se_tfo->queue_status(cmd);
2022                 break;
2023         default:
2024                 break;
2025         }
2026
2027 out:
2028         if (ret < 0) {
2029                 transport_handle_queue_full(cmd, cmd->se_dev);
2030                 return;
2031         }
2032         transport_lun_remove_cmd(cmd);
2033         transport_cmd_check_stop_to_fabric(cmd);
2034 }
2035
2036 static void transport_handle_queue_full(
2037         struct se_cmd *cmd,
2038         struct se_device *dev)
2039 {
2040         spin_lock_irq(&dev->qf_cmd_lock);
2041         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2042         atomic_inc_mb(&dev->dev_qf_count);
2043         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2044
2045         schedule_work(&cmd->se_dev->qf_work_queue);
2046 }
2047
2048 static bool target_read_prot_action(struct se_cmd *cmd)
2049 {
2050         switch (cmd->prot_op) {
2051         case TARGET_PROT_DIN_STRIP:
2052                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2053                         u32 sectors = cmd->data_length >>
2054                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2055
2056                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2057                                                      sectors, 0, cmd->t_prot_sg,
2058                                                      0);
2059                         if (cmd->pi_err)
2060                                 return true;
2061                 }
2062                 break;
2063         case TARGET_PROT_DIN_INSERT:
2064                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2065                         break;
2066
2067                 sbc_dif_generate(cmd);
2068                 break;
2069         default:
2070                 break;
2071         }
2072
2073         return false;
2074 }
2075
2076 static void target_complete_ok_work(struct work_struct *work)
2077 {
2078         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2079         int ret;
2080
2081         /*
2082          * Check if we need to move delayed/dormant tasks from cmds on the
2083          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2084          * Attribute.
2085          */
2086         transport_complete_task_attr(cmd);
2087
2088         /*
2089          * Check to schedule QUEUE_FULL work, or execute an existing
2090          * cmd->transport_qf_callback()
2091          */
2092         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2093                 schedule_work(&cmd->se_dev->qf_work_queue);
2094
2095         /*
2096          * Check if we need to send a sense buffer from
2097          * the struct se_cmd in question.
2098          */
2099         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2100                 WARN_ON(!cmd->scsi_status);
2101                 ret = transport_send_check_condition_and_sense(
2102                                         cmd, 0, 1);
2103                 if (ret == -EAGAIN || ret == -ENOMEM)
2104                         goto queue_full;
2105
2106                 transport_lun_remove_cmd(cmd);
2107                 transport_cmd_check_stop_to_fabric(cmd);
2108                 return;
2109         }
2110         /*
2111          * Check for a callback, used by amongst other things
2112          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2113          */
2114         if (cmd->transport_complete_callback) {
2115                 sense_reason_t rc;
2116                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2117                 bool zero_dl = !(cmd->data_length);
2118                 int post_ret = 0;
2119
2120                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2121                 if (!rc && !post_ret) {
2122                         if (caw && zero_dl)
2123                                 goto queue_rsp;
2124
2125                         return;
2126                 } else if (rc) {
2127                         ret = transport_send_check_condition_and_sense(cmd,
2128                                                 rc, 0);
2129                         if (ret == -EAGAIN || ret == -ENOMEM)
2130                                 goto queue_full;
2131
2132                         transport_lun_remove_cmd(cmd);
2133                         transport_cmd_check_stop_to_fabric(cmd);
2134                         return;
2135                 }
2136         }
2137
2138 queue_rsp:
2139         switch (cmd->data_direction) {
2140         case DMA_FROM_DEVICE:
2141                 if (cmd->scsi_status)
2142                         goto queue_status;
2143
2144                 atomic_long_add(cmd->data_length,
2145                                 &cmd->se_lun->lun_stats.tx_data_octets);
2146                 /*
2147                  * Perform READ_STRIP of PI using software emulation when
2148                  * backend had PI enabled, if the transport will not be
2149                  * performing hardware READ_STRIP offload.
2150                  */
2151                 if (target_read_prot_action(cmd)) {
2152                         ret = transport_send_check_condition_and_sense(cmd,
2153                                                 cmd->pi_err, 0);
2154                         if (ret == -EAGAIN || ret == -ENOMEM)
2155                                 goto queue_full;
2156
2157                         transport_lun_remove_cmd(cmd);
2158                         transport_cmd_check_stop_to_fabric(cmd);
2159                         return;
2160                 }
2161
2162                 trace_target_cmd_complete(cmd);
2163                 ret = cmd->se_tfo->queue_data_in(cmd);
2164                 if (ret == -EAGAIN || ret == -ENOMEM)
2165                         goto queue_full;
2166                 break;
2167         case DMA_TO_DEVICE:
2168                 atomic_long_add(cmd->data_length,
2169                                 &cmd->se_lun->lun_stats.rx_data_octets);
2170                 /*
2171                  * Check if we need to send READ payload for BIDI-COMMAND
2172                  */
2173                 if (cmd->se_cmd_flags & SCF_BIDI) {
2174                         atomic_long_add(cmd->data_length,
2175                                         &cmd->se_lun->lun_stats.tx_data_octets);
2176                         ret = cmd->se_tfo->queue_data_in(cmd);
2177                         if (ret == -EAGAIN || ret == -ENOMEM)
2178                                 goto queue_full;
2179                         break;
2180                 }
2181                 /* Fall through for DMA_TO_DEVICE */
2182         case DMA_NONE:
2183 queue_status:
2184                 trace_target_cmd_complete(cmd);
2185                 ret = cmd->se_tfo->queue_status(cmd);
2186                 if (ret == -EAGAIN || ret == -ENOMEM)
2187                         goto queue_full;
2188                 break;
2189         default:
2190                 break;
2191         }
2192
2193         transport_lun_remove_cmd(cmd);
2194         transport_cmd_check_stop_to_fabric(cmd);
2195         return;
2196
2197 queue_full:
2198         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2199                 " data_direction: %d\n", cmd, cmd->data_direction);
2200         cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2201         transport_handle_queue_full(cmd, cmd->se_dev);
2202 }
2203
2204 void target_free_sgl(struct scatterlist *sgl, int nents)
2205 {
2206         struct scatterlist *sg;
2207         int count;
2208
2209         for_each_sg(sgl, sg, nents, count)
2210                 __free_page(sg_page(sg));
2211
2212         kfree(sgl);
2213 }
2214 EXPORT_SYMBOL(target_free_sgl);
2215
2216 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2217 {
2218         /*
2219          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2220          * emulation, and free + reset pointers if necessary..
2221          */
2222         if (!cmd->t_data_sg_orig)
2223                 return;
2224
2225         kfree(cmd->t_data_sg);
2226         cmd->t_data_sg = cmd->t_data_sg_orig;
2227         cmd->t_data_sg_orig = NULL;
2228         cmd->t_data_nents = cmd->t_data_nents_orig;
2229         cmd->t_data_nents_orig = 0;
2230 }
2231
2232 static inline void transport_free_pages(struct se_cmd *cmd)
2233 {
2234         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2235                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2236                 cmd->t_prot_sg = NULL;
2237                 cmd->t_prot_nents = 0;
2238         }
2239
2240         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2241                 /*
2242                  * Release special case READ buffer payload required for
2243                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2244                  */
2245                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2246                         target_free_sgl(cmd->t_bidi_data_sg,
2247                                            cmd->t_bidi_data_nents);
2248                         cmd->t_bidi_data_sg = NULL;
2249                         cmd->t_bidi_data_nents = 0;
2250                 }
2251                 transport_reset_sgl_orig(cmd);
2252                 return;
2253         }
2254         transport_reset_sgl_orig(cmd);
2255
2256         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2257         cmd->t_data_sg = NULL;
2258         cmd->t_data_nents = 0;
2259
2260         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2261         cmd->t_bidi_data_sg = NULL;
2262         cmd->t_bidi_data_nents = 0;
2263 }
2264
2265 /**
2266  * transport_put_cmd - release a reference to a command
2267  * @cmd:       command to release
2268  *
2269  * This routine releases our reference to the command and frees it if possible.
2270  */
2271 static int transport_put_cmd(struct se_cmd *cmd)
2272 {
2273         BUG_ON(!cmd->se_tfo);
2274         /*
2275          * If this cmd has been setup with target_get_sess_cmd(), drop
2276          * the kref and call ->release_cmd() in kref callback.
2277          */
2278         return target_put_sess_cmd(cmd);
2279 }
2280
2281 void *transport_kmap_data_sg(struct se_cmd *cmd)
2282 {
2283         struct scatterlist *sg = cmd->t_data_sg;
2284         struct page **pages;
2285         int i;
2286
2287         /*
2288          * We need to take into account a possible offset here for fabrics like
2289          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2290          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2291          */
2292         if (!cmd->t_data_nents)
2293                 return NULL;
2294
2295         BUG_ON(!sg);
2296         if (cmd->t_data_nents == 1)
2297                 return kmap(sg_page(sg)) + sg->offset;
2298
2299         /* >1 page. use vmap */
2300         pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2301         if (!pages)
2302                 return NULL;
2303
2304         /* convert sg[] to pages[] */
2305         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2306                 pages[i] = sg_page(sg);
2307         }
2308
2309         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2310         kfree(pages);
2311         if (!cmd->t_data_vmap)
2312                 return NULL;
2313
2314         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2315 }
2316 EXPORT_SYMBOL(transport_kmap_data_sg);
2317
2318 void transport_kunmap_data_sg(struct se_cmd *cmd)
2319 {
2320         if (!cmd->t_data_nents) {
2321                 return;
2322         } else if (cmd->t_data_nents == 1) {
2323                 kunmap(sg_page(cmd->t_data_sg));
2324                 return;
2325         }
2326
2327         vunmap(cmd->t_data_vmap);
2328         cmd->t_data_vmap = NULL;
2329 }
2330 EXPORT_SYMBOL(transport_kunmap_data_sg);
2331
2332 int
2333 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2334                  bool zero_page, bool chainable)
2335 {
2336         struct scatterlist *sg;
2337         struct page *page;
2338         gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2339         unsigned int nalloc, nent;
2340         int i = 0;
2341
2342         nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2343         if (chainable)
2344                 nalloc++;
2345         sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2346         if (!sg)
2347                 return -ENOMEM;
2348
2349         sg_init_table(sg, nalloc);
2350
2351         while (length) {
2352                 u32 page_len = min_t(u32, length, PAGE_SIZE);
2353                 page = alloc_page(GFP_KERNEL | zero_flag);
2354                 if (!page)
2355                         goto out;
2356
2357                 sg_set_page(&sg[i], page, page_len, 0);
2358                 length -= page_len;
2359                 i++;
2360         }
2361         *sgl = sg;
2362         *nents = nent;
2363         return 0;
2364
2365 out:
2366         while (i > 0) {
2367                 i--;
2368                 __free_page(sg_page(&sg[i]));
2369         }
2370         kfree(sg);
2371         return -ENOMEM;
2372 }
2373 EXPORT_SYMBOL(target_alloc_sgl);
2374
2375 /*
2376  * Allocate any required resources to execute the command.  For writes we
2377  * might not have the payload yet, so notify the fabric via a call to
2378  * ->write_pending instead. Otherwise place it on the execution queue.
2379  */
2380 sense_reason_t
2381 transport_generic_new_cmd(struct se_cmd *cmd)
2382 {
2383         int ret = 0;
2384         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2385
2386         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2387             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2388                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2389                                        cmd->prot_length, true, false);
2390                 if (ret < 0)
2391                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2392         }
2393
2394         /*
2395          * Determine is the TCM fabric module has already allocated physical
2396          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2397          * beforehand.
2398          */
2399         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2400             cmd->data_length) {
2401
2402                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2403                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2404                         u32 bidi_length;
2405
2406                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2407                                 bidi_length = cmd->t_task_nolb *
2408                                               cmd->se_dev->dev_attrib.block_size;
2409                         else
2410                                 bidi_length = cmd->data_length;
2411
2412                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2413                                                &cmd->t_bidi_data_nents,
2414                                                bidi_length, zero_flag, false);
2415                         if (ret < 0)
2416                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2417                 }
2418
2419                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2420                                        cmd->data_length, zero_flag, false);
2421                 if (ret < 0)
2422                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2423         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2424                     cmd->data_length) {
2425                 /*
2426                  * Special case for COMPARE_AND_WRITE with fabrics
2427                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2428                  */
2429                 u32 caw_length = cmd->t_task_nolb *
2430                                  cmd->se_dev->dev_attrib.block_size;
2431
2432                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2433                                        &cmd->t_bidi_data_nents,
2434                                        caw_length, zero_flag, false);
2435                 if (ret < 0)
2436                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2437         }
2438         /*
2439          * If this command is not a write we can execute it right here,
2440          * for write buffers we need to notify the fabric driver first
2441          * and let it call back once the write buffers are ready.
2442          */
2443         target_add_to_state_list(cmd);
2444         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2445                 target_execute_cmd(cmd);
2446                 return 0;
2447         }
2448         transport_cmd_check_stop(cmd, false, true);
2449
2450         ret = cmd->se_tfo->write_pending(cmd);
2451         if (ret == -EAGAIN || ret == -ENOMEM)
2452                 goto queue_full;
2453
2454         /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2455         WARN_ON(ret);
2456
2457         return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2458
2459 queue_full:
2460         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2461         cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2462         transport_handle_queue_full(cmd, cmd->se_dev);
2463         return 0;
2464 }
2465 EXPORT_SYMBOL(transport_generic_new_cmd);
2466
2467 static void transport_write_pending_qf(struct se_cmd *cmd)
2468 {
2469         int ret;
2470
2471         ret = cmd->se_tfo->write_pending(cmd);
2472         if (ret == -EAGAIN || ret == -ENOMEM) {
2473                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2474                          cmd);
2475                 transport_handle_queue_full(cmd, cmd->se_dev);
2476         }
2477 }
2478
2479 static bool
2480 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2481                            unsigned long *flags);
2482
2483 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2484 {
2485         unsigned long flags;
2486
2487         spin_lock_irqsave(&cmd->t_state_lock, flags);
2488         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2489         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2490 }
2491
2492 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2493 {
2494         int ret = 0;
2495         bool aborted = false, tas = false;
2496
2497         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2498                 if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2499                         target_wait_free_cmd(cmd, &aborted, &tas);
2500
2501                 if (!aborted || tas)
2502                         ret = transport_put_cmd(cmd);
2503         } else {
2504                 if (wait_for_tasks)
2505                         target_wait_free_cmd(cmd, &aborted, &tas);
2506                 /*
2507                  * Handle WRITE failure case where transport_generic_new_cmd()
2508                  * has already added se_cmd to state_list, but fabric has
2509                  * failed command before I/O submission.
2510                  */
2511                 if (cmd->state_active)
2512                         target_remove_from_state_list(cmd);
2513
2514                 if (cmd->se_lun)
2515                         transport_lun_remove_cmd(cmd);
2516
2517                 if (!aborted || tas)
2518                         ret = transport_put_cmd(cmd);
2519         }
2520         /*
2521          * If the task has been internally aborted due to TMR ABORT_TASK
2522          * or LUN_RESET, target_core_tmr.c is responsible for performing
2523          * the remaining calls to target_put_sess_cmd(), and not the
2524          * callers of this function.
2525          */
2526         if (aborted) {
2527                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2528                 wait_for_completion(&cmd->cmd_wait_comp);
2529                 cmd->se_tfo->release_cmd(cmd);
2530                 ret = 1;
2531         }
2532         return ret;
2533 }
2534 EXPORT_SYMBOL(transport_generic_free_cmd);
2535
2536 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2537  * @se_cmd:     command descriptor to add
2538  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2539  */
2540 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2541 {
2542         struct se_session *se_sess = se_cmd->se_sess;
2543         unsigned long flags;
2544         int ret = 0;
2545
2546         /*
2547          * Add a second kref if the fabric caller is expecting to handle
2548          * fabric acknowledgement that requires two target_put_sess_cmd()
2549          * invocations before se_cmd descriptor release.
2550          */
2551         if (ack_kref) {
2552                 kref_get(&se_cmd->cmd_kref);
2553                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2554         }
2555
2556         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2557         if (se_sess->sess_tearing_down) {
2558                 ret = -ESHUTDOWN;
2559                 goto out;
2560         }
2561         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2562 out:
2563         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2564
2565         if (ret && ack_kref)
2566                 target_put_sess_cmd(se_cmd);
2567
2568         return ret;
2569 }
2570 EXPORT_SYMBOL(target_get_sess_cmd);
2571
2572 static void target_free_cmd_mem(struct se_cmd *cmd)
2573 {
2574         transport_free_pages(cmd);
2575
2576         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2577                 core_tmr_release_req(cmd->se_tmr_req);
2578         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2579                 kfree(cmd->t_task_cdb);
2580 }
2581
2582 static void target_release_cmd_kref(struct kref *kref)
2583 {
2584         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2585         struct se_session *se_sess = se_cmd->se_sess;
2586         unsigned long flags;
2587         bool fabric_stop;
2588
2589         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2590
2591         spin_lock(&se_cmd->t_state_lock);
2592         fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2593                       (se_cmd->transport_state & CMD_T_ABORTED);
2594         spin_unlock(&se_cmd->t_state_lock);
2595
2596         if (se_cmd->cmd_wait_set || fabric_stop) {
2597                 list_del_init(&se_cmd->se_cmd_list);
2598                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2599                 target_free_cmd_mem(se_cmd);
2600                 complete(&se_cmd->cmd_wait_comp);
2601                 return;
2602         }
2603         list_del_init(&se_cmd->se_cmd_list);
2604         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2605
2606         target_free_cmd_mem(se_cmd);
2607         se_cmd->se_tfo->release_cmd(se_cmd);
2608 }
2609
2610 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2611  * @se_cmd:     command descriptor to drop
2612  */
2613 int target_put_sess_cmd(struct se_cmd *se_cmd)
2614 {
2615         struct se_session *se_sess = se_cmd->se_sess;
2616
2617         if (!se_sess) {
2618                 target_free_cmd_mem(se_cmd);
2619                 se_cmd->se_tfo->release_cmd(se_cmd);
2620                 return 1;
2621         }
2622         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2623 }
2624 EXPORT_SYMBOL(target_put_sess_cmd);
2625
2626 /* target_sess_cmd_list_set_waiting - Flag all commands in
2627  *         sess_cmd_list to complete cmd_wait_comp.  Set
2628  *         sess_tearing_down so no more commands are queued.
2629  * @se_sess:    session to flag
2630  */
2631 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2632 {
2633         struct se_cmd *se_cmd;
2634         unsigned long flags;
2635         int rc;
2636
2637         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2638         if (se_sess->sess_tearing_down) {
2639                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2640                 return;
2641         }
2642         se_sess->sess_tearing_down = 1;
2643         list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2644
2645         list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list) {
2646                 rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2647                 if (rc) {
2648                         se_cmd->cmd_wait_set = 1;
2649                         spin_lock(&se_cmd->t_state_lock);
2650                         se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2651                         spin_unlock(&se_cmd->t_state_lock);
2652                 }
2653         }
2654
2655         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2656 }
2657 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2658
2659 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2660  * @se_sess:    session to wait for active I/O
2661  */
2662 void target_wait_for_sess_cmds(struct se_session *se_sess)
2663 {
2664         struct se_cmd *se_cmd, *tmp_cmd;
2665         unsigned long flags;
2666         bool tas;
2667
2668         list_for_each_entry_safe(se_cmd, tmp_cmd,
2669                                 &se_sess->sess_wait_list, se_cmd_list) {
2670                 pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2671                         " %d\n", se_cmd, se_cmd->t_state,
2672                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2673
2674                 spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2675                 tas = (se_cmd->transport_state & CMD_T_TAS);
2676                 spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2677
2678                 if (!target_put_sess_cmd(se_cmd)) {
2679                         if (tas)
2680                                 target_put_sess_cmd(se_cmd);
2681                 }
2682
2683                 wait_for_completion(&se_cmd->cmd_wait_comp);
2684                 pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2685                         " fabric state: %d\n", se_cmd, se_cmd->t_state,
2686                         se_cmd->se_tfo->get_cmd_state(se_cmd));
2687
2688                 se_cmd->se_tfo->release_cmd(se_cmd);
2689         }
2690
2691         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2692         WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2693         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2694
2695 }
2696 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2697
2698 void transport_clear_lun_ref(struct se_lun *lun)
2699 {
2700         percpu_ref_kill(&lun->lun_ref);
2701         wait_for_completion(&lun->lun_ref_comp);
2702 }
2703
2704 static bool
2705 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2706                            bool *aborted, bool *tas, unsigned long *flags)
2707         __releases(&cmd->t_state_lock)
2708         __acquires(&cmd->t_state_lock)
2709 {
2710
2711         assert_spin_locked(&cmd->t_state_lock);
2712         WARN_ON_ONCE(!irqs_disabled());
2713
2714         if (fabric_stop)
2715                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2716
2717         if (cmd->transport_state & CMD_T_ABORTED)
2718                 *aborted = true;
2719
2720         if (cmd->transport_state & CMD_T_TAS)
2721                 *tas = true;
2722
2723         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2724             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2725                 return false;
2726
2727         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2728             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2729                 return false;
2730
2731         if (!(cmd->transport_state & CMD_T_ACTIVE))
2732                 return false;
2733
2734         if (fabric_stop && *aborted)
2735                 return false;
2736
2737         cmd->transport_state |= CMD_T_STOP;
2738
2739         pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2740                  " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2741                  cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2742
2743         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2744
2745         wait_for_completion(&cmd->t_transport_stop_comp);
2746
2747         spin_lock_irqsave(&cmd->t_state_lock, *flags);
2748         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2749
2750         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2751                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2752
2753         return true;
2754 }
2755
2756 /**
2757  * transport_wait_for_tasks - wait for completion to occur
2758  * @cmd:        command to wait
2759  *
2760  * Called from frontend fabric context to wait for storage engine
2761  * to pause and/or release frontend generated struct se_cmd.
2762  */
2763 bool transport_wait_for_tasks(struct se_cmd *cmd)
2764 {
2765         unsigned long flags;
2766         bool ret, aborted = false, tas = false;
2767
2768         spin_lock_irqsave(&cmd->t_state_lock, flags);
2769         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2770         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2771
2772         return ret;
2773 }
2774 EXPORT_SYMBOL(transport_wait_for_tasks);
2775
2776 struct sense_info {
2777         u8 key;
2778         u8 asc;
2779         u8 ascq;
2780         bool add_sector_info;
2781 };
2782
2783 static const struct sense_info sense_info_table[] = {
2784         [TCM_NO_SENSE] = {
2785                 .key = NOT_READY
2786         },
2787         [TCM_NON_EXISTENT_LUN] = {
2788                 .key = ILLEGAL_REQUEST,
2789                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2790         },
2791         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
2792                 .key = ILLEGAL_REQUEST,
2793                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2794         },
2795         [TCM_SECTOR_COUNT_TOO_MANY] = {
2796                 .key = ILLEGAL_REQUEST,
2797                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2798         },
2799         [TCM_UNKNOWN_MODE_PAGE] = {
2800                 .key = ILLEGAL_REQUEST,
2801                 .asc = 0x24, /* INVALID FIELD IN CDB */
2802         },
2803         [TCM_CHECK_CONDITION_ABORT_CMD] = {
2804                 .key = ABORTED_COMMAND,
2805                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2806                 .ascq = 0x03,
2807         },
2808         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
2809                 .key = ABORTED_COMMAND,
2810                 .asc = 0x0c, /* WRITE ERROR */
2811                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2812         },
2813         [TCM_INVALID_CDB_FIELD] = {
2814                 .key = ILLEGAL_REQUEST,
2815                 .asc = 0x24, /* INVALID FIELD IN CDB */
2816         },
2817         [TCM_INVALID_PARAMETER_LIST] = {
2818                 .key = ILLEGAL_REQUEST,
2819                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2820         },
2821         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2822                 .key = ILLEGAL_REQUEST,
2823                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2824         },
2825         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2826                 .key = ILLEGAL_REQUEST,
2827                 .asc = 0x0c, /* WRITE ERROR */
2828                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2829         },
2830         [TCM_SERVICE_CRC_ERROR] = {
2831                 .key = ABORTED_COMMAND,
2832                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2833                 .ascq = 0x05, /* N/A */
2834         },
2835         [TCM_SNACK_REJECTED] = {
2836                 .key = ABORTED_COMMAND,
2837                 .asc = 0x11, /* READ ERROR */
2838                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2839         },
2840         [TCM_WRITE_PROTECTED] = {
2841                 .key = DATA_PROTECT,
2842                 .asc = 0x27, /* WRITE PROTECTED */
2843         },
2844         [TCM_ADDRESS_OUT_OF_RANGE] = {
2845                 .key = ILLEGAL_REQUEST,
2846                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2847         },
2848         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2849                 .key = UNIT_ATTENTION,
2850         },
2851         [TCM_CHECK_CONDITION_NOT_READY] = {
2852                 .key = NOT_READY,
2853         },
2854         [TCM_MISCOMPARE_VERIFY] = {
2855                 .key = MISCOMPARE,
2856                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2857                 .ascq = 0x00,
2858         },
2859         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2860                 .key = ABORTED_COMMAND,
2861                 .asc = 0x10,
2862                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2863                 .add_sector_info = true,
2864         },
2865         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2866                 .key = ABORTED_COMMAND,
2867                 .asc = 0x10,
2868                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2869                 .add_sector_info = true,
2870         },
2871         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2872                 .key = ABORTED_COMMAND,
2873                 .asc = 0x10,
2874                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2875                 .add_sector_info = true,
2876         },
2877         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
2878                 .key = COPY_ABORTED,
2879                 .asc = 0x0d,
2880                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
2881
2882         },
2883         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2884                 /*
2885                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
2886                  * Solaris initiators.  Returning NOT READY instead means the
2887                  * operations will be retried a finite number of times and we
2888                  * can survive intermittent errors.
2889                  */
2890                 .key = NOT_READY,
2891                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2892         },
2893 };
2894
2895 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2896 {
2897         const struct sense_info *si;
2898         u8 *buffer = cmd->sense_buffer;
2899         int r = (__force int)reason;
2900         u8 asc, ascq;
2901         bool desc_format = target_sense_desc_format(cmd->se_dev);
2902
2903         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2904                 si = &sense_info_table[r];
2905         else
2906                 si = &sense_info_table[(__force int)
2907                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2908
2909         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2910                 core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2911                 WARN_ON_ONCE(asc == 0);
2912         } else if (si->asc == 0) {
2913                 WARN_ON_ONCE(cmd->scsi_asc == 0);
2914                 asc = cmd->scsi_asc;
2915                 ascq = cmd->scsi_ascq;
2916         } else {
2917                 asc = si->asc;
2918                 ascq = si->ascq;
2919         }
2920
2921         scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2922         if (si->add_sector_info)
2923                 return scsi_set_sense_information(buffer,
2924                                                   cmd->scsi_sense_length,
2925                                                   cmd->bad_sector);
2926
2927         return 0;
2928 }
2929
2930 int
2931 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2932                 sense_reason_t reason, int from_transport)
2933 {
2934         unsigned long flags;
2935
2936         spin_lock_irqsave(&cmd->t_state_lock, flags);
2937         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2938                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2939                 return 0;
2940         }
2941         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2942         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2943
2944         if (!from_transport) {
2945                 int rc;
2946
2947                 cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2948                 cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2949                 cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2950                 rc = translate_sense_reason(cmd, reason);
2951                 if (rc)
2952                         return rc;
2953         }
2954
2955         trace_target_cmd_complete(cmd);
2956         return cmd->se_tfo->queue_status(cmd);
2957 }
2958 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2959
2960 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2961         __releases(&cmd->t_state_lock)
2962         __acquires(&cmd->t_state_lock)
2963 {
2964         assert_spin_locked(&cmd->t_state_lock);
2965         WARN_ON_ONCE(!irqs_disabled());
2966
2967         if (!(cmd->transport_state & CMD_T_ABORTED))
2968                 return 0;
2969         /*
2970          * If cmd has been aborted but either no status is to be sent or it has
2971          * already been sent, just return
2972          */
2973         if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
2974                 if (send_status)
2975                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
2976                 return 1;
2977         }
2978
2979         pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
2980                 " 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
2981
2982         cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2983         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2984         trace_target_cmd_complete(cmd);
2985
2986         spin_unlock_irq(&cmd->t_state_lock);
2987         cmd->se_tfo->queue_status(cmd);
2988         spin_lock_irq(&cmd->t_state_lock);
2989
2990         return 1;
2991 }
2992
2993 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2994 {
2995         int ret;
2996
2997         spin_lock_irq(&cmd->t_state_lock);
2998         ret = __transport_check_aborted_status(cmd, send_status);
2999         spin_unlock_irq(&cmd->t_state_lock);
3000
3001         return ret;
3002 }
3003 EXPORT_SYMBOL(transport_check_aborted_status);
3004
3005 void transport_send_task_abort(struct se_cmd *cmd)
3006 {
3007         unsigned long flags;
3008
3009         spin_lock_irqsave(&cmd->t_state_lock, flags);
3010         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3011                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3012                 return;
3013         }
3014         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3015
3016         /*
3017          * If there are still expected incoming fabric WRITEs, we wait
3018          * until until they have completed before sending a TASK_ABORTED
3019          * response.  This response with TASK_ABORTED status will be
3020          * queued back to fabric module by transport_check_aborted_status().
3021          */
3022         if (cmd->data_direction == DMA_TO_DEVICE) {
3023                 if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3024                         spin_lock_irqsave(&cmd->t_state_lock, flags);
3025                         if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3026                                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3027                                 goto send_abort;
3028                         }
3029                         cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3030                         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3031                         return;
3032                 }
3033         }
3034 send_abort:
3035         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3036
3037         transport_lun_remove_cmd(cmd);
3038
3039         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3040                  cmd->t_task_cdb[0], cmd->tag);
3041
3042         trace_target_cmd_complete(cmd);
3043         cmd->se_tfo->queue_status(cmd);
3044 }
3045
3046 static void target_tmr_work(struct work_struct *work)
3047 {
3048         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3049         struct se_device *dev = cmd->se_dev;
3050         struct se_tmr_req *tmr = cmd->se_tmr_req;
3051         unsigned long flags;
3052         int ret;
3053
3054         spin_lock_irqsave(&cmd->t_state_lock, flags);
3055         if (cmd->transport_state & CMD_T_ABORTED) {
3056                 tmr->response = TMR_FUNCTION_REJECTED;
3057                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3058                 goto check_stop;
3059         }
3060         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3061
3062         switch (tmr->function) {
3063         case TMR_ABORT_TASK:
3064                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3065                 break;
3066         case TMR_ABORT_TASK_SET:
3067         case TMR_CLEAR_ACA:
3068         case TMR_CLEAR_TASK_SET:
3069                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3070                 break;
3071         case TMR_LUN_RESET:
3072                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3073                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3074                                          TMR_FUNCTION_REJECTED;
3075                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3076                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3077                                                cmd->orig_fe_lun, 0x29,
3078                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3079                 }
3080                 break;
3081         case TMR_TARGET_WARM_RESET:
3082                 tmr->response = TMR_FUNCTION_REJECTED;
3083                 break;
3084         case TMR_TARGET_COLD_RESET:
3085                 tmr->response = TMR_FUNCTION_REJECTED;
3086                 break;
3087         default:
3088                 pr_err("Uknown TMR function: 0x%02x.\n",
3089                                 tmr->function);
3090                 tmr->response = TMR_FUNCTION_REJECTED;
3091                 break;
3092         }
3093
3094         spin_lock_irqsave(&cmd->t_state_lock, flags);
3095         if (cmd->transport_state & CMD_T_ABORTED) {
3096                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3097                 goto check_stop;
3098         }
3099         cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3100         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3101
3102         cmd->se_tfo->queue_tm_rsp(cmd);
3103
3104 check_stop:
3105         transport_cmd_check_stop_to_fabric(cmd);
3106 }
3107
3108 int transport_generic_handle_tmr(
3109         struct se_cmd *cmd)
3110 {
3111         unsigned long flags;
3112
3113         spin_lock_irqsave(&cmd->t_state_lock, flags);
3114         cmd->transport_state |= CMD_T_ACTIVE;
3115         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3116
3117         INIT_WORK(&cmd->work, target_tmr_work);
3118         queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3119         return 0;
3120 }
3121 EXPORT_SYMBOL(transport_generic_handle_tmr);
3122
3123 bool
3124 target_check_wce(struct se_device *dev)
3125 {
3126         bool wce = false;
3127
3128         if (dev->transport->get_write_cache)
3129                 wce = dev->transport->get_write_cache(dev);
3130         else if (dev->dev_attrib.emulate_write_cache > 0)
3131                 wce = true;
3132
3133         return wce;
3134 }
3135
3136 bool
3137 target_check_fua(struct se_device *dev)
3138 {
3139         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3140 }