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