root/drivers/target/target_core_transport.c

DEFINITIONS

1. init_se_kmem_caches
2. release_se_kmem_caches
3. scsi_get_new_index
4. transport_subsystem_check_init
5. target_release_sess_cmd_refcnt
6. transport_init_session
7. transport_alloc_session
8. transport_alloc_session_tags
9. transport_init_session_tags
10. __transport_register_session
11. transport_register_session
12. target_setup_session
13. target_show_dynamic_sessions
14. target_complete_nacl
15. target_put_nacl
16. transport_deregister_session_configfs
17. transport_free_session
18. target_release_res
19. transport_deregister_session
20. target_remove_session
21. target_remove_from_state_list
22. transport_cmd_check_stop_to_fabric
23. transport_lun_remove_cmd
24. target_complete_failure_work
25. transport_get_sense_buffer
26. transport_copy_sense_to_cmd
27. target_handle_abort
28. target_abort_work
29. target_cmd_interrupted
30. target_complete_cmd
31. target_complete_cmd_with_length
32. target_add_to_state_list
33. target_qf_do_work
34. transport_dump_cmd_direction
35. transport_dump_dev_state
36. transport_dump_vpd_proto_id
37. transport_set_vpd_proto_id
38. transport_dump_vpd_assoc
39. transport_set_vpd_assoc
40. transport_dump_vpd_ident_type
41. transport_set_vpd_ident_type
42. transport_dump_vpd_ident
43. transport_set_vpd_ident
44. target_check_max_data_sg_nents
45. target_cmd_size_check
46. transport_init_se_cmd
47. transport_check_alloc_task_attr
48. target_setup_cmd_from_cdb
49. transport_handle_cdb_direct
50. transport_generic_map_mem_to_cmd
51. target_submit_cmd_map_sgls
52. target_submit_cmd
53. target_complete_tmr_failure
54. target_lookup_lun_from_tag
55. target_submit_tmr
56. transport_generic_request_failure
57. __target_execute_cmd
58. target_write_prot_action
59. target_handle_task_attr
60. target_execute_cmd
61. target_restart_delayed_cmds
62. transport_complete_task_attr
63. transport_complete_qf
64. transport_handle_queue_full
65. target_read_prot_action
66. target_complete_ok_work
67. target_free_sgl
68. transport_reset_sgl_orig
69. transport_free_pages
70. transport_kmap_data_sg
71. transport_kunmap_data_sg
72. target_alloc_sgl
73. transport_generic_new_cmd
74. transport_write_pending_qf
75. target_wait_free_cmd
76. target_put_cmd_and_wait
77. transport_generic_free_cmd
78. target_get_sess_cmd
79. target_free_cmd_mem
80. target_release_cmd_kref
81. target_put_sess_cmd
82. data_dir_name
83. cmd_state_name
84. target_append_str
85. target_ts_to_str
86. target_tmf_name
87. target_show_cmd
88. target_sess_cmd_list_set_waiting
89. target_wait_for_sess_cmds
90. transport_clear_lun_ref
91. __transport_wait_for_tasks
92. transport_wait_for_tasks
93. translate_sense_reason
94. transport_send_check_condition_and_sense
95. target_send_busy
96. target_tmr_work
97. transport_generic_handle_tmr
98. target_check_wce
99. target_check_fua

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * Filename:  target_core_transport.c
   4  *
   5  * This file contains the Generic Target Engine Core.
   6  *
   7  * (c) Copyright 2002-2013 Datera, Inc.
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  ******************************************************************************/
  12 
  13 #include <linux/net.h>
  14 #include <linux/delay.h>
  15 #include <linux/string.h>
  16 #include <linux/timer.h>
  17 #include <linux/slab.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/kthread.h>
  20 #include <linux/in.h>
  21 #include <linux/cdrom.h>
  22 #include <linux/module.h>
  23 #include <linux/ratelimit.h>
  24 #include <linux/vmalloc.h>
  25 #include <asm/unaligned.h>
  26 #include <net/sock.h>
  27 #include <net/tcp.h>
  28 #include <scsi/scsi_proto.h>
  29 #include <scsi/scsi_common.h>
  30 
  31 #include <target/target_core_base.h>
  32 #include <target/target_core_backend.h>
  33 #include <target/target_core_fabric.h>
  34 
  35 #include "target_core_internal.h"
  36 #include "target_core_alua.h"
  37 #include "target_core_pr.h"
  38 #include "target_core_ua.h"
  39 
  40 #define CREATE_TRACE_POINTS
  41 #include <trace/events/target.h>
  42 
  43 static struct workqueue_struct *target_completion_wq;
  44 static struct kmem_cache *se_sess_cache;
  45 struct kmem_cache *se_ua_cache;
  46 struct kmem_cache *t10_pr_reg_cache;
  47 struct kmem_cache *t10_alua_lu_gp_cache;
  48 struct kmem_cache *t10_alua_lu_gp_mem_cache;
  49 struct kmem_cache *t10_alua_tg_pt_gp_cache;
  50 struct kmem_cache *t10_alua_lba_map_cache;
  51 struct kmem_cache *t10_alua_lba_map_mem_cache;
  52 
  53 static void transport_complete_task_attr(struct se_cmd *cmd);
  54 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
  55 static void transport_handle_queue_full(struct se_cmd *cmd,
  56                 struct se_device *dev, int err, bool write_pending);
  57 static void target_complete_ok_work(struct work_struct *work);
  58 
  59 int init_se_kmem_caches(void)
  60 {
  61         se_sess_cache = kmem_cache_create("se_sess_cache",
  62                         sizeof(struct se_session), __alignof__(struct se_session),
  63                         0, NULL);
  64         if (!se_sess_cache) {
  65                 pr_err("kmem_cache_create() for struct se_session"
  66                                 " failed\n");
  67                 goto out;
  68         }
  69         se_ua_cache = kmem_cache_create("se_ua_cache",
  70                         sizeof(struct se_ua), __alignof__(struct se_ua),
  71                         0, NULL);
  72         if (!se_ua_cache) {
  73                 pr_err("kmem_cache_create() for struct se_ua failed\n");
  74                 goto out_free_sess_cache;
  75         }
  76         t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
  77                         sizeof(struct t10_pr_registration),
  78                         __alignof__(struct t10_pr_registration), 0, NULL);
  79         if (!t10_pr_reg_cache) {
  80                 pr_err("kmem_cache_create() for struct t10_pr_registration"
  81                                 " failed\n");
  82                 goto out_free_ua_cache;
  83         }
  84         t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
  85                         sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
  86                         0, NULL);
  87         if (!t10_alua_lu_gp_cache) {
  88                 pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
  89                                 " failed\n");
  90                 goto out_free_pr_reg_cache;
  91         }
  92         t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
  93                         sizeof(struct t10_alua_lu_gp_member),
  94                         __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
  95         if (!t10_alua_lu_gp_mem_cache) {
  96                 pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
  97                                 "cache failed\n");
  98                 goto out_free_lu_gp_cache;
  99         }
 100         t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
 101                         sizeof(struct t10_alua_tg_pt_gp),
 102                         __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
 103         if (!t10_alua_tg_pt_gp_cache) {
 104                 pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
 105                                 "cache failed\n");
 106                 goto out_free_lu_gp_mem_cache;
 107         }
 108         t10_alua_lba_map_cache = kmem_cache_create(
 109                         "t10_alua_lba_map_cache",
 110                         sizeof(struct t10_alua_lba_map),
 111                         __alignof__(struct t10_alua_lba_map), 0, NULL);
 112         if (!t10_alua_lba_map_cache) {
 113                 pr_err("kmem_cache_create() for t10_alua_lba_map_"
 114                                 "cache failed\n");
 115                 goto out_free_tg_pt_gp_cache;
 116         }
 117         t10_alua_lba_map_mem_cache = kmem_cache_create(
 118                         "t10_alua_lba_map_mem_cache",
 119                         sizeof(struct t10_alua_lba_map_member),
 120                         __alignof__(struct t10_alua_lba_map_member), 0, NULL);
 121         if (!t10_alua_lba_map_mem_cache) {
 122                 pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
 123                                 "cache failed\n");
 124                 goto out_free_lba_map_cache;
 125         }
 126 
 127         target_completion_wq = alloc_workqueue("target_completion",
 128                                                WQ_MEM_RECLAIM, 0);
 129         if (!target_completion_wq)
 130                 goto out_free_lba_map_mem_cache;
 131 
 132         return 0;
 133 
 134 out_free_lba_map_mem_cache:
 135         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 136 out_free_lba_map_cache:
 137         kmem_cache_destroy(t10_alua_lba_map_cache);
 138 out_free_tg_pt_gp_cache:
 139         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 140 out_free_lu_gp_mem_cache:
 141         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 142 out_free_lu_gp_cache:
 143         kmem_cache_destroy(t10_alua_lu_gp_cache);
 144 out_free_pr_reg_cache:
 145         kmem_cache_destroy(t10_pr_reg_cache);
 146 out_free_ua_cache:
 147         kmem_cache_destroy(se_ua_cache);
 148 out_free_sess_cache:
 149         kmem_cache_destroy(se_sess_cache);
 150 out:
 151         return -ENOMEM;
 152 }
 153 
 154 void release_se_kmem_caches(void)
 155 {
 156         destroy_workqueue(target_completion_wq);
 157         kmem_cache_destroy(se_sess_cache);
 158         kmem_cache_destroy(se_ua_cache);
 159         kmem_cache_destroy(t10_pr_reg_cache);
 160         kmem_cache_destroy(t10_alua_lu_gp_cache);
 161         kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 162         kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 163         kmem_cache_destroy(t10_alua_lba_map_cache);
 164         kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 165 }
 166 
 167 /* This code ensures unique mib indexes are handed out. */
 168 static DEFINE_SPINLOCK(scsi_mib_index_lock);
 169 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
 170 
 171 /*
 172  * Allocate a new row index for the entry type specified
 173  */
 174 u32 scsi_get_new_index(scsi_index_t type)
 175 {
 176         u32 new_index;
 177 
 178         BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
 179 
 180         spin_lock(&scsi_mib_index_lock);
 181         new_index = ++scsi_mib_index[type];
 182         spin_unlock(&scsi_mib_index_lock);
 183 
 184         return new_index;
 185 }
 186 
 187 void transport_subsystem_check_init(void)
 188 {
 189         int ret;
 190         static int sub_api_initialized;
 191 
 192         if (sub_api_initialized)
 193                 return;
 194 
 195         ret = IS_ENABLED(CONFIG_TCM_IBLOCK) && request_module("target_core_iblock");
 196         if (ret != 0)
 197                 pr_err("Unable to load target_core_iblock\n");
 198 
 199         ret = IS_ENABLED(CONFIG_TCM_FILEIO) && request_module("target_core_file");
 200         if (ret != 0)
 201                 pr_err("Unable to load target_core_file\n");
 202 
 203         ret = IS_ENABLED(CONFIG_TCM_PSCSI) && request_module("target_core_pscsi");
 204         if (ret != 0)
 205                 pr_err("Unable to load target_core_pscsi\n");
 206 
 207         ret = IS_ENABLED(CONFIG_TCM_USER2) && request_module("target_core_user");
 208         if (ret != 0)
 209                 pr_err("Unable to load target_core_user\n");
 210 
 211         sub_api_initialized = 1;
 212 }
 213 
 214 static void target_release_sess_cmd_refcnt(struct percpu_ref *ref)
 215 {
 216         struct se_session *sess = container_of(ref, typeof(*sess), cmd_count);
 217 
 218         wake_up(&sess->cmd_list_wq);
 219 }
 220 
 221 /**
 222  * transport_init_session - initialize a session object
 223  * @se_sess: Session object pointer.
 224  *
 225  * The caller must have zero-initialized @se_sess before calling this function.
 226  */
 227 int transport_init_session(struct se_session *se_sess)
 228 {
 229         INIT_LIST_HEAD(&se_sess->sess_list);
 230         INIT_LIST_HEAD(&se_sess->sess_acl_list);
 231         INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 232         spin_lock_init(&se_sess->sess_cmd_lock);
 233         init_waitqueue_head(&se_sess->cmd_list_wq);
 234         return percpu_ref_init(&se_sess->cmd_count,
 235                                target_release_sess_cmd_refcnt, 0, GFP_KERNEL);
 236 }
 237 EXPORT_SYMBOL(transport_init_session);
 238 
 239 /**
 240  * transport_alloc_session - allocate a session object and initialize it
 241  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
 242  */
 243 struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
 244 {
 245         struct se_session *se_sess;
 246         int ret;
 247 
 248         se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 249         if (!se_sess) {
 250                 pr_err("Unable to allocate struct se_session from"
 251                                 " se_sess_cache\n");
 252                 return ERR_PTR(-ENOMEM);
 253         }
 254         ret = transport_init_session(se_sess);
 255         if (ret < 0) {
 256                 kmem_cache_free(se_sess_cache, se_sess);
 257                 return ERR_PTR(ret);
 258         }
 259         se_sess->sup_prot_ops = sup_prot_ops;
 260 
 261         return se_sess;
 262 }
 263 EXPORT_SYMBOL(transport_alloc_session);
 264 
 265 /**
 266  * transport_alloc_session_tags - allocate target driver private data
 267  * @se_sess:  Session pointer.
 268  * @tag_num:  Maximum number of in-flight commands between initiator and target.
 269  * @tag_size: Size in bytes of the private data a target driver associates with
 270  *            each command.
 271  */
 272 int transport_alloc_session_tags(struct se_session *se_sess,
 273                                  unsigned int tag_num, unsigned int tag_size)
 274 {
 275         int rc;
 276 
 277         se_sess->sess_cmd_map = kvcalloc(tag_size, tag_num,
 278                                          GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 279         if (!se_sess->sess_cmd_map) {
 280                 pr_err("Unable to allocate se_sess->sess_cmd_map\n");
 281                 return -ENOMEM;
 282         }
 283 
 284         rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
 285                         false, GFP_KERNEL, NUMA_NO_NODE);
 286         if (rc < 0) {
 287                 pr_err("Unable to init se_sess->sess_tag_pool,"
 288                         " tag_num: %u\n", tag_num);
 289                 kvfree(se_sess->sess_cmd_map);
 290                 se_sess->sess_cmd_map = NULL;
 291                 return -ENOMEM;
 292         }
 293 
 294         return 0;
 295 }
 296 EXPORT_SYMBOL(transport_alloc_session_tags);
 297 
 298 /**
 299  * transport_init_session_tags - allocate a session and target driver private data
 300  * @tag_num:  Maximum number of in-flight commands between initiator and target.
 301  * @tag_size: Size in bytes of the private data a target driver associates with
 302  *            each command.
 303  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
 304  */
 305 static struct se_session *
 306 transport_init_session_tags(unsigned int tag_num, unsigned int tag_size,
 307                             enum target_prot_op sup_prot_ops)
 308 {
 309         struct se_session *se_sess;
 310         int rc;
 311 
 312         if (tag_num != 0 && !tag_size) {
 313                 pr_err("init_session_tags called with percpu-ida tag_num:"
 314                        " %u, but zero tag_size\n", tag_num);
 315                 return ERR_PTR(-EINVAL);
 316         }
 317         if (!tag_num && tag_size) {
 318                 pr_err("init_session_tags called with percpu-ida tag_size:"
 319                        " %u, but zero tag_num\n", tag_size);
 320                 return ERR_PTR(-EINVAL);
 321         }
 322 
 323         se_sess = transport_alloc_session(sup_prot_ops);
 324         if (IS_ERR(se_sess))
 325                 return se_sess;
 326 
 327         rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
 328         if (rc < 0) {
 329                 transport_free_session(se_sess);
 330                 return ERR_PTR(-ENOMEM);
 331         }
 332 
 333         return se_sess;
 334 }
 335 
 336 /*
 337  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
 338  */
 339 void __transport_register_session(
 340         struct se_portal_group *se_tpg,
 341         struct se_node_acl *se_nacl,
 342         struct se_session *se_sess,
 343         void *fabric_sess_ptr)
 344 {
 345         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 346         unsigned char buf[PR_REG_ISID_LEN];
 347         unsigned long flags;
 348 
 349         se_sess->se_tpg = se_tpg;
 350         se_sess->fabric_sess_ptr = fabric_sess_ptr;
 351         /*
 352          * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
 353          *
 354          * Only set for struct se_session's that will actually be moving I/O.
 355          * eg: *NOT* discovery sessions.
 356          */
 357         if (se_nacl) {
 358                 /*
 359                  *
 360                  * Determine if fabric allows for T10-PI feature bits exposed to
 361                  * initiators for device backends with !dev->dev_attrib.pi_prot_type.
 362                  *
 363                  * If so, then always save prot_type on a per se_node_acl node
 364                  * basis and re-instate the previous sess_prot_type to avoid
 365                  * disabling PI from below any previously initiator side
 366                  * registered LUNs.
 367                  */
 368                 if (se_nacl->saved_prot_type)
 369                         se_sess->sess_prot_type = se_nacl->saved_prot_type;
 370                 else if (tfo->tpg_check_prot_fabric_only)
 371                         se_sess->sess_prot_type = se_nacl->saved_prot_type =
 372                                         tfo->tpg_check_prot_fabric_only(se_tpg);
 373                 /*
 374                  * If the fabric module supports an ISID based TransportID,
 375                  * save this value in binary from the fabric I_T Nexus now.
 376                  */
 377                 if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
 378                         memset(&buf[0], 0, PR_REG_ISID_LEN);
 379                         se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
 380                                         &buf[0], PR_REG_ISID_LEN);
 381                         se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
 382                 }
 383 
 384                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 385                 /*
 386                  * The se_nacl->nacl_sess pointer will be set to the
 387                  * last active I_T Nexus for each struct se_node_acl.
 388                  */
 389                 se_nacl->nacl_sess = se_sess;
 390 
 391                 list_add_tail(&se_sess->sess_acl_list,
 392                               &se_nacl->acl_sess_list);
 393                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 394         }
 395         list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
 396 
 397         pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
 398                 se_tpg->se_tpg_tfo->fabric_name, se_sess->fabric_sess_ptr);
 399 }
 400 EXPORT_SYMBOL(__transport_register_session);
 401 
 402 void transport_register_session(
 403         struct se_portal_group *se_tpg,
 404         struct se_node_acl *se_nacl,
 405         struct se_session *se_sess,
 406         void *fabric_sess_ptr)
 407 {
 408         unsigned long flags;
 409 
 410         spin_lock_irqsave(&se_tpg->session_lock, flags);
 411         __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
 412         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 413 }
 414 EXPORT_SYMBOL(transport_register_session);
 415 
 416 struct se_session *
 417 target_setup_session(struct se_portal_group *tpg,
 418                      unsigned int tag_num, unsigned int tag_size,
 419                      enum target_prot_op prot_op,
 420                      const char *initiatorname, void *private,
 421                      int (*callback)(struct se_portal_group *,
 422                                      struct se_session *, void *))
 423 {
 424         struct se_session *sess;
 425 
 426         /*
 427          * If the fabric driver is using percpu-ida based pre allocation
 428          * of I/O descriptor tags, go ahead and perform that setup now..
 429          */
 430         if (tag_num != 0)
 431                 sess = transport_init_session_tags(tag_num, tag_size, prot_op);
 432         else
 433                 sess = transport_alloc_session(prot_op);
 434 
 435         if (IS_ERR(sess))
 436                 return sess;
 437 
 438         sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
 439                                         (unsigned char *)initiatorname);
 440         if (!sess->se_node_acl) {
 441                 transport_free_session(sess);
 442                 return ERR_PTR(-EACCES);
 443         }
 444         /*
 445          * Go ahead and perform any remaining fabric setup that is
 446          * required before transport_register_session().
 447          */
 448         if (callback != NULL) {
 449                 int rc = callback(tpg, sess, private);
 450                 if (rc) {
 451                         transport_free_session(sess);
 452                         return ERR_PTR(rc);
 453                 }
 454         }
 455 
 456         transport_register_session(tpg, sess->se_node_acl, sess, private);
 457         return sess;
 458 }
 459 EXPORT_SYMBOL(target_setup_session);
 460 
 461 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
 462 {
 463         struct se_session *se_sess;
 464         ssize_t len = 0;
 465 
 466         spin_lock_bh(&se_tpg->session_lock);
 467         list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
 468                 if (!se_sess->se_node_acl)
 469                         continue;
 470                 if (!se_sess->se_node_acl->dynamic_node_acl)
 471                         continue;
 472                 if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
 473                         break;
 474 
 475                 len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 476                                 se_sess->se_node_acl->initiatorname);
 477                 len += 1; /* Include NULL terminator */
 478         }
 479         spin_unlock_bh(&se_tpg->session_lock);
 480 
 481         return len;
 482 }
 483 EXPORT_SYMBOL(target_show_dynamic_sessions);
 484 
 485 static void target_complete_nacl(struct kref *kref)
 486 {
 487         struct se_node_acl *nacl = container_of(kref,
 488                                 struct se_node_acl, acl_kref);
 489         struct se_portal_group *se_tpg = nacl->se_tpg;
 490 
 491         if (!nacl->dynamic_stop) {
 492                 complete(&nacl->acl_free_comp);
 493                 return;
 494         }
 495 
 496         mutex_lock(&se_tpg->acl_node_mutex);
 497         list_del_init(&nacl->acl_list);
 498         mutex_unlock(&se_tpg->acl_node_mutex);
 499 
 500         core_tpg_wait_for_nacl_pr_ref(nacl);
 501         core_free_device_list_for_node(nacl, se_tpg);
 502         kfree(nacl);
 503 }
 504 
 505 void target_put_nacl(struct se_node_acl *nacl)
 506 {
 507         kref_put(&nacl->acl_kref, target_complete_nacl);
 508 }
 509 EXPORT_SYMBOL(target_put_nacl);
 510 
 511 void transport_deregister_session_configfs(struct se_session *se_sess)
 512 {
 513         struct se_node_acl *se_nacl;
 514         unsigned long flags;
 515         /*
 516          * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
 517          */
 518         se_nacl = se_sess->se_node_acl;
 519         if (se_nacl) {
 520                 spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 521                 if (!list_empty(&se_sess->sess_acl_list))
 522                         list_del_init(&se_sess->sess_acl_list);
 523                 /*
 524                  * If the session list is empty, then clear the pointer.
 525                  * Otherwise, set the struct se_session pointer from the tail
 526                  * element of the per struct se_node_acl active session list.
 527                  */
 528                 if (list_empty(&se_nacl->acl_sess_list))
 529                         se_nacl->nacl_sess = NULL;
 530                 else {
 531                         se_nacl->nacl_sess = container_of(
 532                                         se_nacl->acl_sess_list.prev,
 533                                         struct se_session, sess_acl_list);
 534                 }
 535                 spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 536         }
 537 }
 538 EXPORT_SYMBOL(transport_deregister_session_configfs);
 539 
 540 void transport_free_session(struct se_session *se_sess)
 541 {
 542         struct se_node_acl *se_nacl = se_sess->se_node_acl;
 543 
 544         /*
 545          * Drop the se_node_acl->nacl_kref obtained from within
 546          * core_tpg_get_initiator_node_acl().
 547          */
 548         if (se_nacl) {
 549                 struct se_portal_group *se_tpg = se_nacl->se_tpg;
 550                 const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
 551                 unsigned long flags;
 552 
 553                 se_sess->se_node_acl = NULL;
 554 
 555                 /*
 556                  * Also determine if we need to drop the extra ->cmd_kref if
 557                  * it had been previously dynamically generated, and
 558                  * the endpoint is not caching dynamic ACLs.
 559                  */
 560                 mutex_lock(&se_tpg->acl_node_mutex);
 561                 if (se_nacl->dynamic_node_acl &&
 562                     !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
 563                         spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
 564                         if (list_empty(&se_nacl->acl_sess_list))
 565                                 se_nacl->dynamic_stop = true;
 566                         spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
 567 
 568                         if (se_nacl->dynamic_stop)
 569                                 list_del_init(&se_nacl->acl_list);
 570                 }
 571                 mutex_unlock(&se_tpg->acl_node_mutex);
 572 
 573                 if (se_nacl->dynamic_stop)
 574                         target_put_nacl(se_nacl);
 575 
 576                 target_put_nacl(se_nacl);
 577         }
 578         if (se_sess->sess_cmd_map) {
 579                 sbitmap_queue_free(&se_sess->sess_tag_pool);
 580                 kvfree(se_sess->sess_cmd_map);
 581         }
 582         percpu_ref_exit(&se_sess->cmd_count);
 583         kmem_cache_free(se_sess_cache, se_sess);
 584 }
 585 EXPORT_SYMBOL(transport_free_session);
 586 
 587 static int target_release_res(struct se_device *dev, void *data)
 588 {
 589         struct se_session *sess = data;
 590 
 591         if (dev->reservation_holder == sess)
 592                 target_release_reservation(dev);
 593         return 0;
 594 }
 595 
 596 void transport_deregister_session(struct se_session *se_sess)
 597 {
 598         struct se_portal_group *se_tpg = se_sess->se_tpg;
 599         unsigned long flags;
 600 
 601         if (!se_tpg) {
 602                 transport_free_session(se_sess);
 603                 return;
 604         }
 605 
 606         spin_lock_irqsave(&se_tpg->session_lock, flags);
 607         list_del(&se_sess->sess_list);
 608         se_sess->se_tpg = NULL;
 609         se_sess->fabric_sess_ptr = NULL;
 610         spin_unlock_irqrestore(&se_tpg->session_lock, flags);
 611 
 612         /*
 613          * Since the session is being removed, release SPC-2
 614          * reservations held by the session that is disappearing.
 615          */
 616         target_for_each_device(target_release_res, se_sess);
 617 
 618         pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
 619                 se_tpg->se_tpg_tfo->fabric_name);
 620         /*
 621          * If last kref is dropping now for an explicit NodeACL, awake sleeping
 622          * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
 623          * removal context from within transport_free_session() code.
 624          *
 625          * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
 626          * to release all remaining generate_node_acl=1 created ACL resources.
 627          */
 628 
 629         transport_free_session(se_sess);
 630 }
 631 EXPORT_SYMBOL(transport_deregister_session);
 632 
 633 void target_remove_session(struct se_session *se_sess)
 634 {
 635         transport_deregister_session_configfs(se_sess);
 636         transport_deregister_session(se_sess);
 637 }
 638 EXPORT_SYMBOL(target_remove_session);
 639 
 640 static void target_remove_from_state_list(struct se_cmd *cmd)
 641 {
 642         struct se_device *dev = cmd->se_dev;
 643         unsigned long flags;
 644 
 645         if (!dev)
 646                 return;
 647 
 648         spin_lock_irqsave(&dev->execute_task_lock, flags);
 649         if (cmd->state_active) {
 650                 list_del(&cmd->state_list);
 651                 cmd->state_active = false;
 652         }
 653         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 654 }
 655 
 656 /*
 657  * This function is called by the target core after the target core has
 658  * finished processing a SCSI command or SCSI TMF. Both the regular command
 659  * processing code and the code for aborting commands can call this
 660  * function. CMD_T_STOP is set if and only if another thread is waiting
 661  * inside transport_wait_for_tasks() for t_transport_stop_comp.
 662  */
 663 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
 664 {
 665         unsigned long flags;
 666 
 667         target_remove_from_state_list(cmd);
 668 
 669         /*
 670          * Clear struct se_cmd->se_lun before the handoff to FE.
 671          */
 672         cmd->se_lun = NULL;
 673 
 674         spin_lock_irqsave(&cmd->t_state_lock, flags);
 675         /*
 676          * Determine if frontend context caller is requesting the stopping of
 677          * this command for frontend exceptions.
 678          */
 679         if (cmd->transport_state & CMD_T_STOP) {
 680                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
 681                         __func__, __LINE__, cmd->tag);
 682 
 683                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 684 
 685                 complete_all(&cmd->t_transport_stop_comp);
 686                 return 1;
 687         }
 688         cmd->transport_state &= ~CMD_T_ACTIVE;
 689         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 690 
 691         /*
 692          * Some fabric modules like tcm_loop can release their internally
 693          * allocated I/O reference and struct se_cmd now.
 694          *
 695          * Fabric modules are expected to return '1' here if the se_cmd being
 696          * passed is released at this point, or zero if not being released.
 697          */
 698         return cmd->se_tfo->check_stop_free(cmd);
 699 }
 700 
 701 static void transport_lun_remove_cmd(struct se_cmd *cmd)
 702 {
 703         struct se_lun *lun = cmd->se_lun;
 704 
 705         if (!lun)
 706                 return;
 707 
 708         if (cmpxchg(&cmd->lun_ref_active, true, false))
 709                 percpu_ref_put(&lun->lun_ref);
 710 }
 711 
 712 static void target_complete_failure_work(struct work_struct *work)
 713 {
 714         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 715 
 716         transport_generic_request_failure(cmd,
 717                         TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
 718 }
 719 
 720 /*
 721  * Used when asking transport to copy Sense Data from the underlying
 722  * Linux/SCSI struct scsi_cmnd
 723  */
 724 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 725 {
 726         struct se_device *dev = cmd->se_dev;
 727 
 728         WARN_ON(!cmd->se_lun);
 729 
 730         if (!dev)
 731                 return NULL;
 732 
 733         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 734                 return NULL;
 735 
 736         cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
 737 
 738         pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 739                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 740         return cmd->sense_buffer;
 741 }
 742 
 743 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
 744 {
 745         unsigned char *cmd_sense_buf;
 746         unsigned long flags;
 747 
 748         spin_lock_irqsave(&cmd->t_state_lock, flags);
 749         cmd_sense_buf = transport_get_sense_buffer(cmd);
 750         if (!cmd_sense_buf) {
 751                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 752                 return;
 753         }
 754 
 755         cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
 756         memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
 757         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 758 }
 759 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
 760 
 761 static void target_handle_abort(struct se_cmd *cmd)
 762 {
 763         bool tas = cmd->transport_state & CMD_T_TAS;
 764         bool ack_kref = cmd->se_cmd_flags & SCF_ACK_KREF;
 765         int ret;
 766 
 767         pr_debug("tag %#llx: send_abort_response = %d\n", cmd->tag, tas);
 768 
 769         if (tas) {
 770                 if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
 771                         cmd->scsi_status = SAM_STAT_TASK_ABORTED;
 772                         pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
 773                                  cmd->t_task_cdb[0], cmd->tag);
 774                         trace_target_cmd_complete(cmd);
 775                         ret = cmd->se_tfo->queue_status(cmd);
 776                         if (ret) {
 777                                 transport_handle_queue_full(cmd, cmd->se_dev,
 778                                                             ret, false);
 779                                 return;
 780                         }
 781                 } else {
 782                         cmd->se_tmr_req->response = TMR_FUNCTION_REJECTED;
 783                         cmd->se_tfo->queue_tm_rsp(cmd);
 784                 }
 785         } else {
 786                 /*
 787                  * Allow the fabric driver to unmap any resources before
 788                  * releasing the descriptor via TFO->release_cmd().
 789                  */
 790                 cmd->se_tfo->aborted_task(cmd);
 791                 if (ack_kref)
 792                         WARN_ON_ONCE(target_put_sess_cmd(cmd) != 0);
 793                 /*
 794                  * To do: establish a unit attention condition on the I_T
 795                  * nexus associated with cmd. See also the paragraph "Aborting
 796                  * commands" in SAM.
 797                  */
 798         }
 799 
 800         WARN_ON_ONCE(kref_read(&cmd->cmd_kref) == 0);
 801 
 802         transport_lun_remove_cmd(cmd);
 803 
 804         transport_cmd_check_stop_to_fabric(cmd);
 805 }
 806 
 807 static void target_abort_work(struct work_struct *work)
 808 {
 809         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
 810 
 811         target_handle_abort(cmd);
 812 }
 813 
 814 static bool target_cmd_interrupted(struct se_cmd *cmd)
 815 {
 816         int post_ret;
 817 
 818         if (cmd->transport_state & CMD_T_ABORTED) {
 819                 if (cmd->transport_complete_callback)
 820                         cmd->transport_complete_callback(cmd, false, &post_ret);
 821                 INIT_WORK(&cmd->work, target_abort_work);
 822                 queue_work(target_completion_wq, &cmd->work);
 823                 return true;
 824         } else if (cmd->transport_state & CMD_T_STOP) {
 825                 if (cmd->transport_complete_callback)
 826                         cmd->transport_complete_callback(cmd, false, &post_ret);
 827                 complete_all(&cmd->t_transport_stop_comp);
 828                 return true;
 829         }
 830 
 831         return false;
 832 }
 833 
 834 /* May be called from interrupt context so must not sleep. */
 835 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
 836 {
 837         int success;
 838         unsigned long flags;
 839 
 840         if (target_cmd_interrupted(cmd))
 841                 return;
 842 
 843         cmd->scsi_status = scsi_status;
 844 
 845         spin_lock_irqsave(&cmd->t_state_lock, flags);
 846         switch (cmd->scsi_status) {
 847         case SAM_STAT_CHECK_CONDITION:
 848                 if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
 849                         success = 1;
 850                 else
 851                         success = 0;
 852                 break;
 853         default:
 854                 success = 1;
 855                 break;
 856         }
 857 
 858         cmd->t_state = TRANSPORT_COMPLETE;
 859         cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
 860         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 861 
 862         INIT_WORK(&cmd->work, success ? target_complete_ok_work :
 863                   target_complete_failure_work);
 864         if (cmd->se_cmd_flags & SCF_USE_CPUID)
 865                 queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
 866         else
 867                 queue_work(target_completion_wq, &cmd->work);
 868 }
 869 EXPORT_SYMBOL(target_complete_cmd);
 870 
 871 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
 872 {
 873         if ((scsi_status == SAM_STAT_GOOD ||
 874              cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
 875             length < cmd->data_length) {
 876                 if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
 877                         cmd->residual_count += cmd->data_length - length;
 878                 } else {
 879                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
 880                         cmd->residual_count = cmd->data_length - length;
 881                 }
 882 
 883                 cmd->data_length = length;
 884         }
 885 
 886         target_complete_cmd(cmd, scsi_status);
 887 }
 888 EXPORT_SYMBOL(target_complete_cmd_with_length);
 889 
 890 static void target_add_to_state_list(struct se_cmd *cmd)
 891 {
 892         struct se_device *dev = cmd->se_dev;
 893         unsigned long flags;
 894 
 895         spin_lock_irqsave(&dev->execute_task_lock, flags);
 896         if (!cmd->state_active) {
 897                 list_add_tail(&cmd->state_list, &dev->state_list);
 898                 cmd->state_active = true;
 899         }
 900         spin_unlock_irqrestore(&dev->execute_task_lock, flags);
 901 }
 902 
 903 /*
 904  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 905  */
 906 static void transport_write_pending_qf(struct se_cmd *cmd);
 907 static void transport_complete_qf(struct se_cmd *cmd);
 908 
 909 void target_qf_do_work(struct work_struct *work)
 910 {
 911         struct se_device *dev = container_of(work, struct se_device,
 912                                         qf_work_queue);
 913         LIST_HEAD(qf_cmd_list);
 914         struct se_cmd *cmd, *cmd_tmp;
 915 
 916         spin_lock_irq(&dev->qf_cmd_lock);
 917         list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
 918         spin_unlock_irq(&dev->qf_cmd_lock);
 919 
 920         list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
 921                 list_del(&cmd->se_qf_node);
 922                 atomic_dec_mb(&dev->dev_qf_count);
 923 
 924                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
 925                         " context: %s\n", cmd->se_tfo->fabric_name, cmd,
 926                         (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
 927                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
 928                         : "UNKNOWN");
 929 
 930                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
 931                         transport_write_pending_qf(cmd);
 932                 else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
 933                          cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
 934                         transport_complete_qf(cmd);
 935         }
 936 }
 937 
 938 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
 939 {
 940         switch (cmd->data_direction) {
 941         case DMA_NONE:
 942                 return "NONE";
 943         case DMA_FROM_DEVICE:
 944                 return "READ";
 945         case DMA_TO_DEVICE:
 946                 return "WRITE";
 947         case DMA_BIDIRECTIONAL:
 948                 return "BIDI";
 949         default:
 950                 break;
 951         }
 952 
 953         return "UNKNOWN";
 954 }
 955 
 956 void transport_dump_dev_state(
 957         struct se_device *dev,
 958         char *b,
 959         int *bl)
 960 {
 961         *bl += sprintf(b + *bl, "Status: ");
 962         if (dev->export_count)
 963                 *bl += sprintf(b + *bl, "ACTIVATED");
 964         else
 965                 *bl += sprintf(b + *bl, "DEACTIVATED");
 966 
 967         *bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
 968         *bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
 969                 dev->dev_attrib.block_size,
 970                 dev->dev_attrib.hw_max_sectors);
 971         *bl += sprintf(b + *bl, "        ");
 972 }
 973 
 974 void transport_dump_vpd_proto_id(
 975         struct t10_vpd *vpd,
 976         unsigned char *p_buf,
 977         int p_buf_len)
 978 {
 979         unsigned char buf[VPD_TMP_BUF_SIZE];
 980         int len;
 981 
 982         memset(buf, 0, VPD_TMP_BUF_SIZE);
 983         len = sprintf(buf, "T10 VPD Protocol Identifier: ");
 984 
 985         switch (vpd->protocol_identifier) {
 986         case 0x00:
 987                 sprintf(buf+len, "Fibre Channel\n");
 988                 break;
 989         case 0x10:
 990                 sprintf(buf+len, "Parallel SCSI\n");
 991                 break;
 992         case 0x20:
 993                 sprintf(buf+len, "SSA\n");
 994                 break;
 995         case 0x30:
 996                 sprintf(buf+len, "IEEE 1394\n");
 997                 break;
 998         case 0x40:
 999                 sprintf(buf+len, "SCSI Remote Direct Memory Access"
1000                                 " Protocol\n");
1001                 break;
1002         case 0x50:
1003                 sprintf(buf+len, "Internet SCSI (iSCSI)\n");
1004                 break;
1005         case 0x60:
1006                 sprintf(buf+len, "SAS Serial SCSI Protocol\n");
1007                 break;
1008         case 0x70:
1009                 sprintf(buf+len, "Automation/Drive Interface Transport"
1010                                 " Protocol\n");
1011                 break;
1012         case 0x80:
1013                 sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
1014                 break;
1015         default:
1016                 sprintf(buf+len, "Unknown 0x%02x\n",
1017                                 vpd->protocol_identifier);
1018                 break;
1019         }
1020 
1021         if (p_buf)
1022                 strncpy(p_buf, buf, p_buf_len);
1023         else
1024                 pr_debug("%s", buf);
1025 }
1026 
1027 void
1028 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
1029 {
1030         /*
1031          * Check if the Protocol Identifier Valid (PIV) bit is set..
1032          *
1033          * from spc3r23.pdf section 7.5.1
1034          */
1035          if (page_83[1] & 0x80) {
1036                 vpd->protocol_identifier = (page_83[0] & 0xf0);
1037                 vpd->protocol_identifier_set = 1;
1038                 transport_dump_vpd_proto_id(vpd, NULL, 0);
1039         }
1040 }
1041 EXPORT_SYMBOL(transport_set_vpd_proto_id);
1042 
1043 int transport_dump_vpd_assoc(
1044         struct t10_vpd *vpd,
1045         unsigned char *p_buf,
1046         int p_buf_len)
1047 {
1048         unsigned char buf[VPD_TMP_BUF_SIZE];
1049         int ret = 0;
1050         int len;
1051 
1052         memset(buf, 0, VPD_TMP_BUF_SIZE);
1053         len = sprintf(buf, "T10 VPD Identifier Association: ");
1054 
1055         switch (vpd->association) {
1056         case 0x00:
1057                 sprintf(buf+len, "addressed logical unit\n");
1058                 break;
1059         case 0x10:
1060                 sprintf(buf+len, "target port\n");
1061                 break;
1062         case 0x20:
1063                 sprintf(buf+len, "SCSI target device\n");
1064                 break;
1065         default:
1066                 sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
1067                 ret = -EINVAL;
1068                 break;
1069         }
1070 
1071         if (p_buf)
1072                 strncpy(p_buf, buf, p_buf_len);
1073         else
1074                 pr_debug("%s", buf);
1075 
1076         return ret;
1077 }
1078 
1079 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
1080 {
1081         /*
1082          * The VPD identification association..
1083          *
1084          * from spc3r23.pdf Section 7.6.3.1 Table 297
1085          */
1086         vpd->association = (page_83[1] & 0x30);
1087         return transport_dump_vpd_assoc(vpd, NULL, 0);
1088 }
1089 EXPORT_SYMBOL(transport_set_vpd_assoc);
1090 
1091 int transport_dump_vpd_ident_type(
1092         struct t10_vpd *vpd,
1093         unsigned char *p_buf,
1094         int p_buf_len)
1095 {
1096         unsigned char buf[VPD_TMP_BUF_SIZE];
1097         int ret = 0;
1098         int len;
1099 
1100         memset(buf, 0, VPD_TMP_BUF_SIZE);
1101         len = sprintf(buf, "T10 VPD Identifier Type: ");
1102 
1103         switch (vpd->device_identifier_type) {
1104         case 0x00:
1105                 sprintf(buf+len, "Vendor specific\n");
1106                 break;
1107         case 0x01:
1108                 sprintf(buf+len, "T10 Vendor ID based\n");
1109                 break;
1110         case 0x02:
1111                 sprintf(buf+len, "EUI-64 based\n");
1112                 break;
1113         case 0x03:
1114                 sprintf(buf+len, "NAA\n");
1115                 break;
1116         case 0x04:
1117                 sprintf(buf+len, "Relative target port identifier\n");
1118                 break;
1119         case 0x08:
1120                 sprintf(buf+len, "SCSI name string\n");
1121                 break;
1122         default:
1123                 sprintf(buf+len, "Unsupported: 0x%02x\n",
1124                                 vpd->device_identifier_type);
1125                 ret = -EINVAL;
1126                 break;
1127         }
1128 
1129         if (p_buf) {
1130                 if (p_buf_len < strlen(buf)+1)
1131                         return -EINVAL;
1132                 strncpy(p_buf, buf, p_buf_len);
1133         } else {
1134                 pr_debug("%s", buf);
1135         }
1136 
1137         return ret;
1138 }
1139 
1140 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1141 {
1142         /*
1143          * The VPD identifier type..
1144          *
1145          * from spc3r23.pdf Section 7.6.3.1 Table 298
1146          */
1147         vpd->device_identifier_type = (page_83[1] & 0x0f);
1148         return transport_dump_vpd_ident_type(vpd, NULL, 0);
1149 }
1150 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1151 
1152 int transport_dump_vpd_ident(
1153         struct t10_vpd *vpd,
1154         unsigned char *p_buf,
1155         int p_buf_len)
1156 {
1157         unsigned char buf[VPD_TMP_BUF_SIZE];
1158         int ret = 0;
1159 
1160         memset(buf, 0, VPD_TMP_BUF_SIZE);
1161 
1162         switch (vpd->device_identifier_code_set) {
1163         case 0x01: /* Binary */
1164                 snprintf(buf, sizeof(buf),
1165                         "T10 VPD Binary Device Identifier: %s\n",
1166                         &vpd->device_identifier[0]);
1167                 break;
1168         case 0x02: /* ASCII */
1169                 snprintf(buf, sizeof(buf),
1170                         "T10 VPD ASCII Device Identifier: %s\n",
1171                         &vpd->device_identifier[0]);
1172                 break;
1173         case 0x03: /* UTF-8 */
1174                 snprintf(buf, sizeof(buf),
1175                         "T10 VPD UTF-8 Device Identifier: %s\n",
1176                         &vpd->device_identifier[0]);
1177                 break;
1178         default:
1179                 sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1180                         " 0x%02x", vpd->device_identifier_code_set);
1181                 ret = -EINVAL;
1182                 break;
1183         }
1184 
1185         if (p_buf)
1186                 strncpy(p_buf, buf, p_buf_len);
1187         else
1188                 pr_debug("%s", buf);
1189 
1190         return ret;
1191 }
1192 
1193 int
1194 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1195 {
1196         static const char hex_str[] = "0123456789abcdef";
1197         int j = 0, i = 4; /* offset to start of the identifier */
1198 
1199         /*
1200          * The VPD Code Set (encoding)
1201          *
1202          * from spc3r23.pdf Section 7.6.3.1 Table 296
1203          */
1204         vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1205         switch (vpd->device_identifier_code_set) {
1206         case 0x01: /* Binary */
1207                 vpd->device_identifier[j++] =
1208                                 hex_str[vpd->device_identifier_type];
1209                 while (i < (4 + page_83[3])) {
1210                         vpd->device_identifier[j++] =
1211                                 hex_str[(page_83[i] & 0xf0) >> 4];
1212                         vpd->device_identifier[j++] =
1213                                 hex_str[page_83[i] & 0x0f];
1214                         i++;
1215                 }
1216                 break;
1217         case 0x02: /* ASCII */
1218         case 0x03: /* UTF-8 */
1219                 while (i < (4 + page_83[3]))
1220                         vpd->device_identifier[j++] = page_83[i++];
1221                 break;
1222         default:
1223                 break;
1224         }
1225 
1226         return transport_dump_vpd_ident(vpd, NULL, 0);
1227 }
1228 EXPORT_SYMBOL(transport_set_vpd_ident);
1229 
1230 static sense_reason_t
1231 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1232                                unsigned int size)
1233 {
1234         u32 mtl;
1235 
1236         if (!cmd->se_tfo->max_data_sg_nents)
1237                 return TCM_NO_SENSE;
1238         /*
1239          * Check if fabric enforced maximum SGL entries per I/O descriptor
1240          * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1241          * residual_count and reduce original cmd->data_length to maximum
1242          * length based on single PAGE_SIZE entry scatter-lists.
1243          */
1244         mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1245         if (cmd->data_length > mtl) {
1246                 /*
1247                  * If an existing CDB overflow is present, calculate new residual
1248                  * based on CDB size minus fabric maximum transfer length.
1249                  *
1250                  * If an existing CDB underflow is present, calculate new residual
1251                  * based on original cmd->data_length minus fabric maximum transfer
1252                  * length.
1253                  *
1254                  * Otherwise, set the underflow residual based on cmd->data_length
1255                  * minus fabric maximum transfer length.
1256                  */
1257                 if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1258                         cmd->residual_count = (size - mtl);
1259                 } else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1260                         u32 orig_dl = size + cmd->residual_count;
1261                         cmd->residual_count = (orig_dl - mtl);
1262                 } else {
1263                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1264                         cmd->residual_count = (cmd->data_length - mtl);
1265                 }
1266                 cmd->data_length = mtl;
1267                 /*
1268                  * Reset sbc_check_prot() calculated protection payload
1269                  * length based upon the new smaller MTL.
1270                  */
1271                 if (cmd->prot_length) {
1272                         u32 sectors = (mtl / dev->dev_attrib.block_size);
1273                         cmd->prot_length = dev->prot_length * sectors;
1274                 }
1275         }
1276         return TCM_NO_SENSE;
1277 }
1278 
1279 sense_reason_t
1280 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1281 {
1282         struct se_device *dev = cmd->se_dev;
1283 
1284         if (cmd->unknown_data_length) {
1285                 cmd->data_length = size;
1286         } else if (size != cmd->data_length) {
1287                 pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1288                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"
1289                         " 0x%02x\n", cmd->se_tfo->fabric_name,
1290                                 cmd->data_length, size, cmd->t_task_cdb[0]);
1291 
1292                 if (cmd->data_direction == DMA_TO_DEVICE) {
1293                         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1294                                 pr_err_ratelimited("Rejecting underflow/overflow"
1295                                                    " for WRITE data CDB\n");
1296                                 return TCM_INVALID_CDB_FIELD;
1297                         }
1298                         /*
1299                          * Some fabric drivers like iscsi-target still expect to
1300                          * always reject overflow writes.  Reject this case until
1301                          * full fabric driver level support for overflow writes
1302                          * is introduced tree-wide.
1303                          */
1304                         if (size > cmd->data_length) {
1305                                 pr_err_ratelimited("Rejecting overflow for"
1306                                                    " WRITE control CDB\n");
1307                                 return TCM_INVALID_CDB_FIELD;
1308                         }
1309                 }
1310                 /*
1311                  * Reject READ_* or WRITE_* with overflow/underflow for
1312                  * type SCF_SCSI_DATA_CDB.
1313                  */
1314                 if (dev->dev_attrib.block_size != 512)  {
1315                         pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1316                                 " CDB on non 512-byte sector setup subsystem"
1317                                 " plugin: %s\n", dev->transport->name);
1318                         /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1319                         return TCM_INVALID_CDB_FIELD;
1320                 }
1321                 /*
1322                  * For the overflow case keep the existing fabric provided
1323                  * ->data_length.  Otherwise for the underflow case, reset
1324                  * ->data_length to the smaller SCSI expected data transfer
1325                  * length.
1326                  */
1327                 if (size > cmd->data_length) {
1328                         cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1329                         cmd->residual_count = (size - cmd->data_length);
1330                 } else {
1331                         cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1332                         cmd->residual_count = (cmd->data_length - size);
1333                         cmd->data_length = size;
1334                 }
1335         }
1336 
1337         return target_check_max_data_sg_nents(cmd, dev, size);
1338 
1339 }
1340 
1341 /*
1342  * Used by fabric modules containing a local struct se_cmd within their
1343  * fabric dependent per I/O descriptor.
1344  *
1345  * Preserves the value of @cmd->tag.
1346  */
1347 void transport_init_se_cmd(
1348         struct se_cmd *cmd,
1349         const struct target_core_fabric_ops *tfo,
1350         struct se_session *se_sess,
1351         u32 data_length,
1352         int data_direction,
1353         int task_attr,
1354         unsigned char *sense_buffer)
1355 {
1356         INIT_LIST_HEAD(&cmd->se_delayed_node);
1357         INIT_LIST_HEAD(&cmd->se_qf_node);
1358         INIT_LIST_HEAD(&cmd->se_cmd_list);
1359         INIT_LIST_HEAD(&cmd->state_list);
1360         init_completion(&cmd->t_transport_stop_comp);
1361         cmd->free_compl = NULL;
1362         cmd->abrt_compl = NULL;
1363         spin_lock_init(&cmd->t_state_lock);
1364         INIT_WORK(&cmd->work, NULL);
1365         kref_init(&cmd->cmd_kref);
1366 
1367         cmd->se_tfo = tfo;
1368         cmd->se_sess = se_sess;
1369         cmd->data_length = data_length;
1370         cmd->data_direction = data_direction;
1371         cmd->sam_task_attr = task_attr;
1372         cmd->sense_buffer = sense_buffer;
1373 
1374         cmd->state_active = false;
1375 }
1376 EXPORT_SYMBOL(transport_init_se_cmd);
1377 
1378 static sense_reason_t
1379 transport_check_alloc_task_attr(struct se_cmd *cmd)
1380 {
1381         struct se_device *dev = cmd->se_dev;
1382 
1383         /*
1384          * Check if SAM Task Attribute emulation is enabled for this
1385          * struct se_device storage object
1386          */
1387         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1388                 return 0;
1389 
1390         if (cmd->sam_task_attr == TCM_ACA_TAG) {
1391                 pr_debug("SAM Task Attribute ACA"
1392                         " emulation is not supported\n");
1393                 return TCM_INVALID_CDB_FIELD;
1394         }
1395 
1396         return 0;
1397 }
1398 
1399 sense_reason_t
1400 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1401 {
1402         struct se_device *dev = cmd->se_dev;
1403         sense_reason_t ret;
1404 
1405         /*
1406          * Ensure that the received CDB is less than the max (252 + 8) bytes
1407          * for VARIABLE_LENGTH_CMD
1408          */
1409         if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1410                 pr_err("Received SCSI CDB with command_size: %d that"
1411                         " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1412                         scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1413                 return TCM_INVALID_CDB_FIELD;
1414         }
1415         /*
1416          * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1417          * allocate the additional extended CDB buffer now..  Otherwise
1418          * setup the pointer from __t_task_cdb to t_task_cdb.
1419          */
1420         if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1421                 cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1422                                                 GFP_KERNEL);
1423                 if (!cmd->t_task_cdb) {
1424                         pr_err("Unable to allocate cmd->t_task_cdb"
1425                                 " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1426                                 scsi_command_size(cdb),
1427                                 (unsigned long)sizeof(cmd->__t_task_cdb));
1428                         return TCM_OUT_OF_RESOURCES;
1429                 }
1430         } else
1431                 cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1432         /*
1433          * Copy the original CDB into cmd->
1434          */
1435         memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1436 
1437         trace_target_sequencer_start(cmd);
1438 
1439         ret = dev->transport->parse_cdb(cmd);
1440         if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1441                 pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1442                                     cmd->se_tfo->fabric_name,
1443                                     cmd->se_sess->se_node_acl->initiatorname,
1444                                     cmd->t_task_cdb[0]);
1445         if (ret)
1446                 return ret;
1447 
1448         ret = transport_check_alloc_task_attr(cmd);
1449         if (ret)
1450                 return ret;
1451 
1452         cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1453         atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1454         return 0;
1455 }
1456 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1457 
1458 /*
1459  * Used by fabric module frontends to queue tasks directly.
1460  * May only be used from process context.
1461  */
1462 int transport_handle_cdb_direct(
1463         struct se_cmd *cmd)
1464 {
1465         sense_reason_t ret;
1466 
1467         if (!cmd->se_lun) {
1468                 dump_stack();
1469                 pr_err("cmd->se_lun is NULL\n");
1470                 return -EINVAL;
1471         }
1472         if (in_interrupt()) {
1473                 dump_stack();
1474                 pr_err("transport_generic_handle_cdb cannot be called"
1475                                 " from interrupt context\n");
1476                 return -EINVAL;
1477         }
1478         /*
1479          * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1480          * outstanding descriptors are handled correctly during shutdown via
1481          * transport_wait_for_tasks()
1482          *
1483          * Also, we don't take cmd->t_state_lock here as we only expect
1484          * this to be called for initial descriptor submission.
1485          */
1486         cmd->t_state = TRANSPORT_NEW_CMD;
1487         cmd->transport_state |= CMD_T_ACTIVE;
1488 
1489         /*
1490          * transport_generic_new_cmd() is already handling QUEUE_FULL,
1491          * so follow TRANSPORT_NEW_CMD processing thread context usage
1492          * and call transport_generic_request_failure() if necessary..
1493          */
1494         ret = transport_generic_new_cmd(cmd);
1495         if (ret)
1496                 transport_generic_request_failure(cmd, ret);
1497         return 0;
1498 }
1499 EXPORT_SYMBOL(transport_handle_cdb_direct);
1500 
1501 sense_reason_t
1502 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1503                 u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1504 {
1505         if (!sgl || !sgl_count)
1506                 return 0;
1507 
1508         /*
1509          * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1510          * scatterlists already have been set to follow what the fabric
1511          * passes for the original expected data transfer length.
1512          */
1513         if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1514                 pr_warn("Rejecting SCSI DATA overflow for fabric using"
1515                         " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1516                 return TCM_INVALID_CDB_FIELD;
1517         }
1518 
1519         cmd->t_data_sg = sgl;
1520         cmd->t_data_nents = sgl_count;
1521         cmd->t_bidi_data_sg = sgl_bidi;
1522         cmd->t_bidi_data_nents = sgl_bidi_count;
1523 
1524         cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1525         return 0;
1526 }
1527 
1528 /**
1529  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1530  *                       se_cmd + use pre-allocated SGL memory.
1531  *
1532  * @se_cmd: command descriptor to submit
1533  * @se_sess: associated se_sess for endpoint
1534  * @cdb: pointer to SCSI CDB
1535  * @sense: pointer to SCSI sense buffer
1536  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1537  * @data_length: fabric expected data transfer length
1538  * @task_attr: SAM task attribute
1539  * @data_dir: DMA data direction
1540  * @flags: flags for command submission from target_sc_flags_tables
1541  * @sgl: struct scatterlist memory for unidirectional mapping
1542  * @sgl_count: scatterlist count for unidirectional mapping
1543  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1544  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1545  * @sgl_prot: struct scatterlist memory protection information
1546  * @sgl_prot_count: scatterlist count for protection information
1547  *
1548  * Task tags are supported if the caller has set @se_cmd->tag.
1549  *
1550  * Returns non zero to signal active I/O shutdown failure.  All other
1551  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1552  * but still return zero here.
1553  *
1554  * This may only be called from process context, and also currently
1555  * assumes internal allocation of fabric payload buffer by target-core.
1556  */
1557 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1558                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1559                 u32 data_length, int task_attr, int data_dir, int flags,
1560                 struct scatterlist *sgl, u32 sgl_count,
1561                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1562                 struct scatterlist *sgl_prot, u32 sgl_prot_count)
1563 {
1564         struct se_portal_group *se_tpg;
1565         sense_reason_t rc;
1566         int ret;
1567 
1568         se_tpg = se_sess->se_tpg;
1569         BUG_ON(!se_tpg);
1570         BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1571         BUG_ON(in_interrupt());
1572         /*
1573          * Initialize se_cmd for target operation.  From this point
1574          * exceptions are handled by sending exception status via
1575          * target_core_fabric_ops->queue_status() callback
1576          */
1577         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1578                                 data_length, data_dir, task_attr, sense);
1579 
1580         if (flags & TARGET_SCF_USE_CPUID)
1581                 se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1582         else
1583                 se_cmd->cpuid = WORK_CPU_UNBOUND;
1584 
1585         if (flags & TARGET_SCF_UNKNOWN_SIZE)
1586                 se_cmd->unknown_data_length = 1;
1587         /*
1588          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1589          * se_sess->sess_cmd_list.  A second kref_get here is necessary
1590          * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1591          * kref_put() to happen during fabric packet acknowledgement.
1592          */
1593         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1594         if (ret)
1595                 return ret;
1596         /*
1597          * Signal bidirectional data payloads to target-core
1598          */
1599         if (flags & TARGET_SCF_BIDI_OP)
1600                 se_cmd->se_cmd_flags |= SCF_BIDI;
1601         /*
1602          * Locate se_lun pointer and attach it to struct se_cmd
1603          */
1604         rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1605         if (rc) {
1606                 transport_send_check_condition_and_sense(se_cmd, rc, 0);
1607                 target_put_sess_cmd(se_cmd);
1608                 return 0;
1609         }
1610 
1611         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1612         if (rc != 0) {
1613                 transport_generic_request_failure(se_cmd, rc);
1614                 return 0;
1615         }
1616 
1617         /*
1618          * Save pointers for SGLs containing protection information,
1619          * if present.
1620          */
1621         if (sgl_prot_count) {
1622                 se_cmd->t_prot_sg = sgl_prot;
1623                 se_cmd->t_prot_nents = sgl_prot_count;
1624                 se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1625         }
1626 
1627         /*
1628          * When a non zero sgl_count has been passed perform SGL passthrough
1629          * mapping for pre-allocated fabric memory instead of having target
1630          * core perform an internal SGL allocation..
1631          */
1632         if (sgl_count != 0) {
1633                 BUG_ON(!sgl);
1634 
1635                 /*
1636                  * A work-around for tcm_loop as some userspace code via
1637                  * scsi-generic do not memset their associated read buffers,
1638                  * so go ahead and do that here for type non-data CDBs.  Also
1639                  * note that this is currently guaranteed to be a single SGL
1640                  * for this case by target core in target_setup_cmd_from_cdb()
1641                  * -> transport_generic_cmd_sequencer().
1642                  */
1643                 if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1644                      se_cmd->data_direction == DMA_FROM_DEVICE) {
1645                         unsigned char *buf = NULL;
1646 
1647                         if (sgl)
1648                                 buf = kmap(sg_page(sgl)) + sgl->offset;
1649 
1650                         if (buf) {
1651                                 memset(buf, 0, sgl->length);
1652                                 kunmap(sg_page(sgl));
1653                         }
1654                 }
1655 
1656                 rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1657                                 sgl_bidi, sgl_bidi_count);
1658                 if (rc != 0) {
1659                         transport_generic_request_failure(se_cmd, rc);
1660                         return 0;
1661                 }
1662         }
1663 
1664         /*
1665          * Check if we need to delay processing because of ALUA
1666          * Active/NonOptimized primary access state..
1667          */
1668         core_alua_check_nonop_delay(se_cmd);
1669 
1670         transport_handle_cdb_direct(se_cmd);
1671         return 0;
1672 }
1673 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1674 
1675 /**
1676  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1677  *
1678  * @se_cmd: command descriptor to submit
1679  * @se_sess: associated se_sess for endpoint
1680  * @cdb: pointer to SCSI CDB
1681  * @sense: pointer to SCSI sense buffer
1682  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1683  * @data_length: fabric expected data transfer length
1684  * @task_attr: SAM task attribute
1685  * @data_dir: DMA data direction
1686  * @flags: flags for command submission from target_sc_flags_tables
1687  *
1688  * Task tags are supported if the caller has set @se_cmd->tag.
1689  *
1690  * Returns non zero to signal active I/O shutdown failure.  All other
1691  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1692  * but still return zero here.
1693  *
1694  * This may only be called from process context, and also currently
1695  * assumes internal allocation of fabric payload buffer by target-core.
1696  *
1697  * It also assumes interal target core SGL memory allocation.
1698  */
1699 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1700                 unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1701                 u32 data_length, int task_attr, int data_dir, int flags)
1702 {
1703         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1704                         unpacked_lun, data_length, task_attr, data_dir,
1705                         flags, NULL, 0, NULL, 0, NULL, 0);
1706 }
1707 EXPORT_SYMBOL(target_submit_cmd);
1708 
1709 static void target_complete_tmr_failure(struct work_struct *work)
1710 {
1711         struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1712 
1713         se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1714         se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1715 
1716         transport_lun_remove_cmd(se_cmd);
1717         transport_cmd_check_stop_to_fabric(se_cmd);
1718 }
1719 
1720 static bool target_lookup_lun_from_tag(struct se_session *se_sess, u64 tag,
1721                                        u64 *unpacked_lun)
1722 {
1723         struct se_cmd *se_cmd;
1724         unsigned long flags;
1725         bool ret = false;
1726 
1727         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
1728         list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) {
1729                 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1730                         continue;
1731 
1732                 if (se_cmd->tag == tag) {
1733                         *unpacked_lun = se_cmd->orig_fe_lun;
1734                         ret = true;
1735                         break;
1736                 }
1737         }
1738         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
1739 
1740         return ret;
1741 }
1742 
1743 /**
1744  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1745  *                     for TMR CDBs
1746  *
1747  * @se_cmd: command descriptor to submit
1748  * @se_sess: associated se_sess for endpoint
1749  * @sense: pointer to SCSI sense buffer
1750  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1751  * @fabric_tmr_ptr: fabric context for TMR req
1752  * @tm_type: Type of TM request
1753  * @gfp: gfp type for caller
1754  * @tag: referenced task tag for TMR_ABORT_TASK
1755  * @flags: submit cmd flags
1756  *
1757  * Callable from all contexts.
1758  **/
1759 
1760 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1761                 unsigned char *sense, u64 unpacked_lun,
1762                 void *fabric_tmr_ptr, unsigned char tm_type,
1763                 gfp_t gfp, u64 tag, int flags)
1764 {
1765         struct se_portal_group *se_tpg;
1766         int ret;
1767 
1768         se_tpg = se_sess->se_tpg;
1769         BUG_ON(!se_tpg);
1770 
1771         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1772                               0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1773         /*
1774          * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1775          * allocation failure.
1776          */
1777         ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1778         if (ret < 0)
1779                 return -ENOMEM;
1780 
1781         if (tm_type == TMR_ABORT_TASK)
1782                 se_cmd->se_tmr_req->ref_task_tag = tag;
1783 
1784         /* See target_submit_cmd for commentary */
1785         ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1786         if (ret) {
1787                 core_tmr_release_req(se_cmd->se_tmr_req);
1788                 return ret;
1789         }
1790         /*
1791          * If this is ABORT_TASK with no explicit fabric provided LUN,
1792          * go ahead and search active session tags for a match to figure
1793          * out unpacked_lun for the original se_cmd.
1794          */
1795         if (tm_type == TMR_ABORT_TASK && (flags & TARGET_SCF_LOOKUP_LUN_FROM_TAG)) {
1796                 if (!target_lookup_lun_from_tag(se_sess, tag, &unpacked_lun))
1797                         goto failure;
1798         }
1799 
1800         ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1801         if (ret)
1802                 goto failure;
1803 
1804         transport_generic_handle_tmr(se_cmd);
1805         return 0;
1806 
1807         /*
1808          * For callback during failure handling, push this work off
1809          * to process context with TMR_LUN_DOES_NOT_EXIST status.
1810          */
1811 failure:
1812         INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1813         schedule_work(&se_cmd->work);
1814         return 0;
1815 }
1816 EXPORT_SYMBOL(target_submit_tmr);
1817 
1818 /*
1819  * Handle SAM-esque emulation for generic transport request failures.
1820  */
1821 void transport_generic_request_failure(struct se_cmd *cmd,
1822                 sense_reason_t sense_reason)
1823 {
1824         int ret = 0, post_ret;
1825 
1826         pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
1827                  sense_reason);
1828         target_show_cmd("-----[ ", cmd);
1829 
1830         /*
1831          * For SAM Task Attribute emulation for failed struct se_cmd
1832          */
1833         transport_complete_task_attr(cmd);
1834 
1835         if (cmd->transport_complete_callback)
1836                 cmd->transport_complete_callback(cmd, false, &post_ret);
1837 
1838         if (cmd->transport_state & CMD_T_ABORTED) {
1839                 INIT_WORK(&cmd->work, target_abort_work);
1840                 queue_work(target_completion_wq, &cmd->work);
1841                 return;
1842         }
1843 
1844         switch (sense_reason) {
1845         case TCM_NON_EXISTENT_LUN:
1846         case TCM_UNSUPPORTED_SCSI_OPCODE:
1847         case TCM_INVALID_CDB_FIELD:
1848         case TCM_INVALID_PARAMETER_LIST:
1849         case TCM_PARAMETER_LIST_LENGTH_ERROR:
1850         case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1851         case TCM_UNKNOWN_MODE_PAGE:
1852         case TCM_WRITE_PROTECTED:
1853         case TCM_ADDRESS_OUT_OF_RANGE:
1854         case TCM_CHECK_CONDITION_ABORT_CMD:
1855         case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1856         case TCM_CHECK_CONDITION_NOT_READY:
1857         case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1858         case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1859         case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1860         case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1861         case TCM_TOO_MANY_TARGET_DESCS:
1862         case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1863         case TCM_TOO_MANY_SEGMENT_DESCS:
1864         case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1865                 break;
1866         case TCM_OUT_OF_RESOURCES:
1867                 cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
1868                 goto queue_status;
1869         case TCM_LUN_BUSY:
1870                 cmd->scsi_status = SAM_STAT_BUSY;
1871                 goto queue_status;
1872         case TCM_RESERVATION_CONFLICT:
1873                 /*
1874                  * No SENSE Data payload for this case, set SCSI Status
1875                  * and queue the response to $FABRIC_MOD.
1876                  *
1877                  * Uses linux/include/scsi/scsi.h SAM status codes defs
1878                  */
1879                 cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1880                 /*
1881                  * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1882                  * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1883                  * CONFLICT STATUS.
1884                  *
1885                  * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1886                  */
1887                 if (cmd->se_sess &&
1888                     cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1889                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1890                                                cmd->orig_fe_lun, 0x2C,
1891                                         ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1892                 }
1893 
1894                 goto queue_status;
1895         default:
1896                 pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1897                         cmd->t_task_cdb[0], sense_reason);
1898                 sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1899                 break;
1900         }
1901 
1902         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1903         if (ret)
1904                 goto queue_full;
1905 
1906 check_stop:
1907         transport_lun_remove_cmd(cmd);
1908         transport_cmd_check_stop_to_fabric(cmd);
1909         return;
1910 
1911 queue_status:
1912         trace_target_cmd_complete(cmd);
1913         ret = cmd->se_tfo->queue_status(cmd);
1914         if (!ret)
1915                 goto check_stop;
1916 queue_full:
1917         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1918 }
1919 EXPORT_SYMBOL(transport_generic_request_failure);
1920 
1921 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1922 {
1923         sense_reason_t ret;
1924 
1925         if (!cmd->execute_cmd) {
1926                 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1927                 goto err;
1928         }
1929         if (do_checks) {
1930                 /*
1931                  * Check for an existing UNIT ATTENTION condition after
1932                  * target_handle_task_attr() has done SAM task attr
1933                  * checking, and possibly have already defered execution
1934                  * out to target_restart_delayed_cmds() context.
1935                  */
1936                 ret = target_scsi3_ua_check(cmd);
1937                 if (ret)
1938                         goto err;
1939 
1940                 ret = target_alua_state_check(cmd);
1941                 if (ret)
1942                         goto err;
1943 
1944                 ret = target_check_reservation(cmd);
1945                 if (ret) {
1946                         cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1947                         goto err;
1948                 }
1949         }
1950 
1951         ret = cmd->execute_cmd(cmd);
1952         if (!ret)
1953                 return;
1954 err:
1955         spin_lock_irq(&cmd->t_state_lock);
1956         cmd->transport_state &= ~CMD_T_SENT;
1957         spin_unlock_irq(&cmd->t_state_lock);
1958 
1959         transport_generic_request_failure(cmd, ret);
1960 }
1961 
1962 static int target_write_prot_action(struct se_cmd *cmd)
1963 {
1964         u32 sectors;
1965         /*
1966          * Perform WRITE_INSERT of PI using software emulation when backend
1967          * device has PI enabled, if the transport has not already generated
1968          * PI using hardware WRITE_INSERT offload.
1969          */
1970         switch (cmd->prot_op) {
1971         case TARGET_PROT_DOUT_INSERT:
1972                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1973                         sbc_dif_generate(cmd);
1974                 break;
1975         case TARGET_PROT_DOUT_STRIP:
1976                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1977                         break;
1978 
1979                 sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1980                 cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1981                                              sectors, 0, cmd->t_prot_sg, 0);
1982                 if (unlikely(cmd->pi_err)) {
1983                         spin_lock_irq(&cmd->t_state_lock);
1984                         cmd->transport_state &= ~CMD_T_SENT;
1985                         spin_unlock_irq(&cmd->t_state_lock);
1986                         transport_generic_request_failure(cmd, cmd->pi_err);
1987                         return -1;
1988                 }
1989                 break;
1990         default:
1991                 break;
1992         }
1993 
1994         return 0;
1995 }
1996 
1997 static bool target_handle_task_attr(struct se_cmd *cmd)
1998 {
1999         struct se_device *dev = cmd->se_dev;
2000 
2001         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2002                 return false;
2003 
2004         cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
2005 
2006         /*
2007          * Check for the existence of HEAD_OF_QUEUE, and if true return 1
2008          * to allow the passed struct se_cmd list of tasks to the front of the list.
2009          */
2010         switch (cmd->sam_task_attr) {
2011         case TCM_HEAD_TAG:
2012                 pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
2013                          cmd->t_task_cdb[0]);
2014                 return false;
2015         case TCM_ORDERED_TAG:
2016                 atomic_inc_mb(&dev->dev_ordered_sync);
2017 
2018                 pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
2019                          cmd->t_task_cdb[0]);
2020 
2021                 /*
2022                  * Execute an ORDERED command if no other older commands
2023                  * exist that need to be completed first.
2024                  */
2025                 if (!atomic_read(&dev->simple_cmds))
2026                         return false;
2027                 break;
2028         default:
2029                 /*
2030                  * For SIMPLE and UNTAGGED Task Attribute commands
2031                  */
2032                 atomic_inc_mb(&dev->simple_cmds);
2033                 break;
2034         }
2035 
2036         if (atomic_read(&dev->dev_ordered_sync) == 0)
2037                 return false;
2038 
2039         spin_lock(&dev->delayed_cmd_lock);
2040         list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
2041         spin_unlock(&dev->delayed_cmd_lock);
2042 
2043         pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
2044                 cmd->t_task_cdb[0], cmd->sam_task_attr);
2045         return true;
2046 }
2047 
2048 void target_execute_cmd(struct se_cmd *cmd)
2049 {
2050         /*
2051          * Determine if frontend context caller is requesting the stopping of
2052          * this command for frontend exceptions.
2053          *
2054          * If the received CDB has already been aborted stop processing it here.
2055          */
2056         if (target_cmd_interrupted(cmd))
2057                 return;
2058 
2059         spin_lock_irq(&cmd->t_state_lock);
2060         cmd->t_state = TRANSPORT_PROCESSING;
2061         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
2062         spin_unlock_irq(&cmd->t_state_lock);
2063 
2064         if (target_write_prot_action(cmd))
2065                 return;
2066 
2067         if (target_handle_task_attr(cmd)) {
2068                 spin_lock_irq(&cmd->t_state_lock);
2069                 cmd->transport_state &= ~CMD_T_SENT;
2070                 spin_unlock_irq(&cmd->t_state_lock);
2071                 return;
2072         }
2073 
2074         __target_execute_cmd(cmd, true);
2075 }
2076 EXPORT_SYMBOL(target_execute_cmd);
2077 
2078 /*
2079  * Process all commands up to the last received ORDERED task attribute which
2080  * requires another blocking boundary
2081  */
2082 static void target_restart_delayed_cmds(struct se_device *dev)
2083 {
2084         for (;;) {
2085                 struct se_cmd *cmd;
2086 
2087                 spin_lock(&dev->delayed_cmd_lock);
2088                 if (list_empty(&dev->delayed_cmd_list)) {
2089                         spin_unlock(&dev->delayed_cmd_lock);
2090                         break;
2091                 }
2092 
2093                 cmd = list_entry(dev->delayed_cmd_list.next,
2094                                  struct se_cmd, se_delayed_node);
2095                 list_del(&cmd->se_delayed_node);
2096                 spin_unlock(&dev->delayed_cmd_lock);
2097 
2098                 cmd->transport_state |= CMD_T_SENT;
2099 
2100                 __target_execute_cmd(cmd, true);
2101 
2102                 if (cmd->sam_task_attr == TCM_ORDERED_TAG)
2103                         break;
2104         }
2105 }
2106 
2107 /*
2108  * Called from I/O completion to determine which dormant/delayed
2109  * and ordered cmds need to have their tasks added to the execution queue.
2110  */
2111 static void transport_complete_task_attr(struct se_cmd *cmd)
2112 {
2113         struct se_device *dev = cmd->se_dev;
2114 
2115         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2116                 return;
2117 
2118         if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2119                 goto restart;
2120 
2121         if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2122                 atomic_dec_mb(&dev->simple_cmds);
2123                 dev->dev_cur_ordered_id++;
2124         } else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2125                 dev->dev_cur_ordered_id++;
2126                 pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2127                          dev->dev_cur_ordered_id);
2128         } else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2129                 atomic_dec_mb(&dev->dev_ordered_sync);
2130 
2131                 dev->dev_cur_ordered_id++;
2132                 pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2133                          dev->dev_cur_ordered_id);
2134         }
2135         cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2136 
2137 restart:
2138         target_restart_delayed_cmds(dev);
2139 }
2140 
2141 static void transport_complete_qf(struct se_cmd *cmd)
2142 {
2143         int ret = 0;
2144 
2145         transport_complete_task_attr(cmd);
2146         /*
2147          * If a fabric driver ->write_pending() or ->queue_data_in() callback
2148          * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2149          * the same callbacks should not be retried.  Return CHECK_CONDITION
2150          * if a scsi_status is not already set.
2151          *
2152          * If a fabric driver ->queue_status() has returned non zero, always
2153          * keep retrying no matter what..
2154          */
2155         if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2156                 if (cmd->scsi_status)
2157                         goto queue_status;
2158 
2159                 translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2160                 goto queue_status;
2161         }
2162 
2163         /*
2164          * Check if we need to send a sense buffer from
2165          * the struct se_cmd in question. We do NOT want
2166          * to take this path of the IO has been marked as
2167          * needing to be treated like a "normal read". This
2168          * is the case if it's a tape read, and either the
2169          * FM, EOM, or ILI bits are set, but there is no
2170          * sense data.
2171          */
2172         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2173             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2174                 goto queue_status;
2175 
2176         switch (cmd->data_direction) {
2177         case DMA_FROM_DEVICE:
2178                 /* queue status if not treating this as a normal read */
2179                 if (cmd->scsi_status &&
2180                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2181                         goto queue_status;
2182 
2183                 trace_target_cmd_complete(cmd);
2184                 ret = cmd->se_tfo->queue_data_in(cmd);
2185                 break;
2186         case DMA_TO_DEVICE:
2187                 if (cmd->se_cmd_flags & SCF_BIDI) {
2188                         ret = cmd->se_tfo->queue_data_in(cmd);
2189                         break;
2190                 }
2191                 /* fall through */
2192         case DMA_NONE:
2193 queue_status:
2194                 trace_target_cmd_complete(cmd);
2195                 ret = cmd->se_tfo->queue_status(cmd);
2196                 break;
2197         default:
2198                 break;
2199         }
2200 
2201         if (ret < 0) {
2202                 transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2203                 return;
2204         }
2205         transport_lun_remove_cmd(cmd);
2206         transport_cmd_check_stop_to_fabric(cmd);
2207 }
2208 
2209 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2210                                         int err, bool write_pending)
2211 {
2212         /*
2213          * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2214          * ->queue_data_in() callbacks from new process context.
2215          *
2216          * Otherwise for other errors, transport_complete_qf() will send
2217          * CHECK_CONDITION via ->queue_status() instead of attempting to
2218          * retry associated fabric driver data-transfer callbacks.
2219          */
2220         if (err == -EAGAIN || err == -ENOMEM) {
2221                 cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2222                                                  TRANSPORT_COMPLETE_QF_OK;
2223         } else {
2224                 pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2225                 cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2226         }
2227 
2228         spin_lock_irq(&dev->qf_cmd_lock);
2229         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2230         atomic_inc_mb(&dev->dev_qf_count);
2231         spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2232 
2233         schedule_work(&cmd->se_dev->qf_work_queue);
2234 }
2235 
2236 static bool target_read_prot_action(struct se_cmd *cmd)
2237 {
2238         switch (cmd->prot_op) {
2239         case TARGET_PROT_DIN_STRIP:
2240                 if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2241                         u32 sectors = cmd->data_length >>
2242                                   ilog2(cmd->se_dev->dev_attrib.block_size);
2243 
2244                         cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2245                                                      sectors, 0, cmd->t_prot_sg,
2246                                                      0);
2247                         if (cmd->pi_err)
2248                                 return true;
2249                 }
2250                 break;
2251         case TARGET_PROT_DIN_INSERT:
2252                 if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2253                         break;
2254 
2255                 sbc_dif_generate(cmd);
2256                 break;
2257         default:
2258                 break;
2259         }
2260 
2261         return false;
2262 }
2263 
2264 static void target_complete_ok_work(struct work_struct *work)
2265 {
2266         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2267         int ret;
2268 
2269         /*
2270          * Check if we need to move delayed/dormant tasks from cmds on the
2271          * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2272          * Attribute.
2273          */
2274         transport_complete_task_attr(cmd);
2275 
2276         /*
2277          * Check to schedule QUEUE_FULL work, or execute an existing
2278          * cmd->transport_qf_callback()
2279          */
2280         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2281                 schedule_work(&cmd->se_dev->qf_work_queue);
2282 
2283         /*
2284          * Check if we need to send a sense buffer from
2285          * the struct se_cmd in question. We do NOT want
2286          * to take this path of the IO has been marked as
2287          * needing to be treated like a "normal read". This
2288          * is the case if it's a tape read, and either the
2289          * FM, EOM, or ILI bits are set, but there is no
2290          * sense data.
2291          */
2292         if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2293             cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2294                 WARN_ON(!cmd->scsi_status);
2295                 ret = transport_send_check_condition_and_sense(
2296                                         cmd, 0, 1);
2297                 if (ret)
2298                         goto queue_full;
2299 
2300                 transport_lun_remove_cmd(cmd);
2301                 transport_cmd_check_stop_to_fabric(cmd);
2302                 return;
2303         }
2304         /*
2305          * Check for a callback, used by amongst other things
2306          * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2307          */
2308         if (cmd->transport_complete_callback) {
2309                 sense_reason_t rc;
2310                 bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2311                 bool zero_dl = !(cmd->data_length);
2312                 int post_ret = 0;
2313 
2314                 rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2315                 if (!rc && !post_ret) {
2316                         if (caw && zero_dl)
2317                                 goto queue_rsp;
2318 
2319                         return;
2320                 } else if (rc) {
2321                         ret = transport_send_check_condition_and_sense(cmd,
2322                                                 rc, 0);
2323                         if (ret)
2324                                 goto queue_full;
2325 
2326                         transport_lun_remove_cmd(cmd);
2327                         transport_cmd_check_stop_to_fabric(cmd);
2328                         return;
2329                 }
2330         }
2331 
2332 queue_rsp:
2333         switch (cmd->data_direction) {
2334         case DMA_FROM_DEVICE:
2335                 /*
2336                  * if this is a READ-type IO, but SCSI status
2337                  * is set, then skip returning data and just
2338                  * return the status -- unless this IO is marked
2339                  * as needing to be treated as a normal read,
2340                  * in which case we want to go ahead and return
2341                  * the data. This happens, for example, for tape
2342                  * reads with the FM, EOM, or ILI bits set, with
2343                  * no sense data.
2344                  */
2345                 if (cmd->scsi_status &&
2346                     !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2347                         goto queue_status;
2348 
2349                 atomic_long_add(cmd->data_length,
2350                                 &cmd->se_lun->lun_stats.tx_data_octets);
2351                 /*
2352                  * Perform READ_STRIP of PI using software emulation when
2353                  * backend had PI enabled, if the transport will not be
2354                  * performing hardware READ_STRIP offload.
2355                  */
2356                 if (target_read_prot_action(cmd)) {
2357                         ret = transport_send_check_condition_and_sense(cmd,
2358                                                 cmd->pi_err, 0);
2359                         if (ret)
2360                                 goto queue_full;
2361 
2362                         transport_lun_remove_cmd(cmd);
2363                         transport_cmd_check_stop_to_fabric(cmd);
2364                         return;
2365                 }
2366 
2367                 trace_target_cmd_complete(cmd);
2368                 ret = cmd->se_tfo->queue_data_in(cmd);
2369                 if (ret)
2370                         goto queue_full;
2371                 break;
2372         case DMA_TO_DEVICE:
2373                 atomic_long_add(cmd->data_length,
2374                                 &cmd->se_lun->lun_stats.rx_data_octets);
2375                 /*
2376                  * Check if we need to send READ payload for BIDI-COMMAND
2377                  */
2378                 if (cmd->se_cmd_flags & SCF_BIDI) {
2379                         atomic_long_add(cmd->data_length,
2380                                         &cmd->se_lun->lun_stats.tx_data_octets);
2381                         ret = cmd->se_tfo->queue_data_in(cmd);
2382                         if (ret)
2383                                 goto queue_full;
2384                         break;
2385                 }
2386                 /* fall through */
2387         case DMA_NONE:
2388 queue_status:
2389                 trace_target_cmd_complete(cmd);
2390                 ret = cmd->se_tfo->queue_status(cmd);
2391                 if (ret)
2392                         goto queue_full;
2393                 break;
2394         default:
2395                 break;
2396         }
2397 
2398         transport_lun_remove_cmd(cmd);
2399         transport_cmd_check_stop_to_fabric(cmd);
2400         return;
2401 
2402 queue_full:
2403         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2404                 " data_direction: %d\n", cmd, cmd->data_direction);
2405 
2406         transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2407 }
2408 
2409 void target_free_sgl(struct scatterlist *sgl, int nents)
2410 {
2411         sgl_free_n_order(sgl, nents, 0);
2412 }
2413 EXPORT_SYMBOL(target_free_sgl);
2414 
2415 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2416 {
2417         /*
2418          * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2419          * emulation, and free + reset pointers if necessary..
2420          */
2421         if (!cmd->t_data_sg_orig)
2422                 return;
2423 
2424         kfree(cmd->t_data_sg);
2425         cmd->t_data_sg = cmd->t_data_sg_orig;
2426         cmd->t_data_sg_orig = NULL;
2427         cmd->t_data_nents = cmd->t_data_nents_orig;
2428         cmd->t_data_nents_orig = 0;
2429 }
2430 
2431 static inline void transport_free_pages(struct se_cmd *cmd)
2432 {
2433         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2434                 target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2435                 cmd->t_prot_sg = NULL;
2436                 cmd->t_prot_nents = 0;
2437         }
2438 
2439         if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2440                 /*
2441                  * Release special case READ buffer payload required for
2442                  * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2443                  */
2444                 if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2445                         target_free_sgl(cmd->t_bidi_data_sg,
2446                                            cmd->t_bidi_data_nents);
2447                         cmd->t_bidi_data_sg = NULL;
2448                         cmd->t_bidi_data_nents = 0;
2449                 }
2450                 transport_reset_sgl_orig(cmd);
2451                 return;
2452         }
2453         transport_reset_sgl_orig(cmd);
2454 
2455         target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2456         cmd->t_data_sg = NULL;
2457         cmd->t_data_nents = 0;
2458 
2459         target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2460         cmd->t_bidi_data_sg = NULL;
2461         cmd->t_bidi_data_nents = 0;
2462 }
2463 
2464 void *transport_kmap_data_sg(struct se_cmd *cmd)
2465 {
2466         struct scatterlist *sg = cmd->t_data_sg;
2467         struct page **pages;
2468         int i;
2469 
2470         /*
2471          * We need to take into account a possible offset here for fabrics like
2472          * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2473          * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2474          */
2475         if (!cmd->t_data_nents)
2476                 return NULL;
2477 
2478         BUG_ON(!sg);
2479         if (cmd->t_data_nents == 1)
2480                 return kmap(sg_page(sg)) + sg->offset;
2481 
2482         /* >1 page. use vmap */
2483         pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2484         if (!pages)
2485                 return NULL;
2486 
2487         /* convert sg[] to pages[] */
2488         for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2489                 pages[i] = sg_page(sg);
2490         }
2491 
2492         cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2493         kfree(pages);
2494         if (!cmd->t_data_vmap)
2495                 return NULL;
2496 
2497         return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2498 }
2499 EXPORT_SYMBOL(transport_kmap_data_sg);
2500 
2501 void transport_kunmap_data_sg(struct se_cmd *cmd)
2502 {
2503         if (!cmd->t_data_nents) {
2504                 return;
2505         } else if (cmd->t_data_nents == 1) {
2506                 kunmap(sg_page(cmd->t_data_sg));
2507                 return;
2508         }
2509 
2510         vunmap(cmd->t_data_vmap);
2511         cmd->t_data_vmap = NULL;
2512 }
2513 EXPORT_SYMBOL(transport_kunmap_data_sg);
2514 
2515 int
2516 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2517                  bool zero_page, bool chainable)
2518 {
2519         gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
2520 
2521         *sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
2522         return *sgl ? 0 : -ENOMEM;
2523 }
2524 EXPORT_SYMBOL(target_alloc_sgl);
2525 
2526 /*
2527  * Allocate any required resources to execute the command.  For writes we
2528  * might not have the payload yet, so notify the fabric via a call to
2529  * ->write_pending instead. Otherwise place it on the execution queue.
2530  */
2531 sense_reason_t
2532 transport_generic_new_cmd(struct se_cmd *cmd)
2533 {
2534         unsigned long flags;
2535         int ret = 0;
2536         bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2537 
2538         if (cmd->prot_op != TARGET_PROT_NORMAL &&
2539             !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2540                 ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2541                                        cmd->prot_length, true, false);
2542                 if (ret < 0)
2543                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2544         }
2545 
2546         /*
2547          * Determine if the TCM fabric module has already allocated physical
2548          * memory, and is directly calling transport_generic_map_mem_to_cmd()
2549          * beforehand.
2550          */
2551         if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2552             cmd->data_length) {
2553 
2554                 if ((cmd->se_cmd_flags & SCF_BIDI) ||
2555                     (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2556                         u32 bidi_length;
2557 
2558                         if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2559                                 bidi_length = cmd->t_task_nolb *
2560                                               cmd->se_dev->dev_attrib.block_size;
2561                         else
2562                                 bidi_length = cmd->data_length;
2563 
2564                         ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2565                                                &cmd->t_bidi_data_nents,
2566                                                bidi_length, zero_flag, false);
2567                         if (ret < 0)
2568                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2569                 }
2570 
2571                 ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2572                                        cmd->data_length, zero_flag, false);
2573                 if (ret < 0)
2574                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2575         } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2576                     cmd->data_length) {
2577                 /*
2578                  * Special case for COMPARE_AND_WRITE with fabrics
2579                  * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2580                  */
2581                 u32 caw_length = cmd->t_task_nolb *
2582                                  cmd->se_dev->dev_attrib.block_size;
2583 
2584                 ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2585                                        &cmd->t_bidi_data_nents,
2586                                        caw_length, zero_flag, false);
2587                 if (ret < 0)
2588                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2589         }
2590         /*
2591          * If this command is not a write we can execute it right here,
2592          * for write buffers we need to notify the fabric driver first
2593          * and let it call back once the write buffers are ready.
2594          */
2595         target_add_to_state_list(cmd);
2596         if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2597                 target_execute_cmd(cmd);
2598                 return 0;
2599         }
2600 
2601         spin_lock_irqsave(&cmd->t_state_lock, flags);
2602         cmd->t_state = TRANSPORT_WRITE_PENDING;
2603         /*
2604          * Determine if frontend context caller is requesting the stopping of
2605          * this command for frontend exceptions.
2606          */
2607         if (cmd->transport_state & CMD_T_STOP &&
2608             !cmd->se_tfo->write_pending_must_be_called) {
2609                 pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2610                          __func__, __LINE__, cmd->tag);
2611 
2612                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2613 
2614                 complete_all(&cmd->t_transport_stop_comp);
2615                 return 0;
2616         }
2617         cmd->transport_state &= ~CMD_T_ACTIVE;
2618         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2619 
2620         ret = cmd->se_tfo->write_pending(cmd);
2621         if (ret)
2622                 goto queue_full;
2623 
2624         return 0;
2625 
2626 queue_full:
2627         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2628         transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2629         return 0;
2630 }
2631 EXPORT_SYMBOL(transport_generic_new_cmd);
2632 
2633 static void transport_write_pending_qf(struct se_cmd *cmd)
2634 {
2635         unsigned long flags;
2636         int ret;
2637         bool stop;
2638 
2639         spin_lock_irqsave(&cmd->t_state_lock, flags);
2640         stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2641         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2642 
2643         if (stop) {
2644                 pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2645                         __func__, __LINE__, cmd->tag);
2646                 complete_all(&cmd->t_transport_stop_comp);
2647                 return;
2648         }
2649 
2650         ret = cmd->se_tfo->write_pending(cmd);
2651         if (ret) {
2652                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2653                          cmd);
2654                 transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2655         }
2656 }
2657 
2658 static bool
2659 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2660                            unsigned long *flags);
2661 
2662 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2663 {
2664         unsigned long flags;
2665 
2666         spin_lock_irqsave(&cmd->t_state_lock, flags);
2667         __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2668         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2669 }
2670 
2671 /*
2672  * Call target_put_sess_cmd() and wait until target_release_cmd_kref(@cmd) has
2673  * finished.
2674  */
2675 void target_put_cmd_and_wait(struct se_cmd *cmd)
2676 {
2677         DECLARE_COMPLETION_ONSTACK(compl);
2678 
2679         WARN_ON_ONCE(cmd->abrt_compl);
2680         cmd->abrt_compl = &compl;
2681         target_put_sess_cmd(cmd);
2682         wait_for_completion(&compl);
2683 }
2684 
2685 /*
2686  * This function is called by frontend drivers after processing of a command
2687  * has finished.
2688  *
2689  * The protocol for ensuring that either the regular frontend command
2690  * processing flow or target_handle_abort() code drops one reference is as
2691  * follows:
2692  * - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
2693  *   the frontend driver to call this function synchronously or asynchronously.
2694  *   That will cause one reference to be dropped.
2695  * - During regular command processing the target core sets CMD_T_COMPLETE
2696  *   before invoking one of the .queue_*() functions.
2697  * - The code that aborts commands skips commands and TMFs for which
2698  *   CMD_T_COMPLETE has been set.
2699  * - CMD_T_ABORTED is set atomically after the CMD_T_COMPLETE check for
2700  *   commands that will be aborted.
2701  * - If the CMD_T_ABORTED flag is set but CMD_T_TAS has not been set
2702  *   transport_generic_free_cmd() skips its call to target_put_sess_cmd().
2703  * - For aborted commands for which CMD_T_TAS has been set .queue_status() will
2704  *   be called and will drop a reference.
2705  * - For aborted commands for which CMD_T_TAS has not been set .aborted_task()
2706  *   will be called. target_handle_abort() will drop the final reference.
2707  */
2708 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2709 {
2710         DECLARE_COMPLETION_ONSTACK(compl);
2711         int ret = 0;
2712         bool aborted = false, tas = false;
2713 
2714         if (wait_for_tasks)
2715                 target_wait_free_cmd(cmd, &aborted, &tas);
2716 
2717         if (cmd->se_cmd_flags & SCF_SE_LUN_CMD) {
2718                 /*
2719                  * Handle WRITE failure case where transport_generic_new_cmd()
2720                  * has already added se_cmd to state_list, but fabric has
2721                  * failed command before I/O submission.
2722                  */
2723                 if (cmd->state_active)
2724                         target_remove_from_state_list(cmd);
2725 
2726                 if (cmd->se_lun)
2727                         transport_lun_remove_cmd(cmd);
2728         }
2729         if (aborted)
2730                 cmd->free_compl = &compl;
2731         ret = target_put_sess_cmd(cmd);
2732         if (aborted) {
2733                 pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2734                 wait_for_completion(&compl);
2735                 ret = 1;
2736         }
2737         return ret;
2738 }
2739 EXPORT_SYMBOL(transport_generic_free_cmd);
2740 
2741 /**
2742  * target_get_sess_cmd - Add command to active ->sess_cmd_list
2743  * @se_cmd:     command descriptor to add
2744  * @ack_kref:   Signal that fabric will perform an ack target_put_sess_cmd()
2745  */
2746 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2747 {
2748         struct se_session *se_sess = se_cmd->se_sess;
2749         unsigned long flags;
2750         int ret = 0;
2751 
2752         /*
2753          * Add a second kref if the fabric caller is expecting to handle
2754          * fabric acknowledgement that requires two target_put_sess_cmd()
2755          * invocations before se_cmd descriptor release.
2756          */
2757         if (ack_kref) {
2758                 if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2759                         return -EINVAL;
2760 
2761                 se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2762         }
2763 
2764         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2765         if (se_sess->sess_tearing_down) {
2766                 ret = -ESHUTDOWN;
2767                 goto out;
2768         }
2769         list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2770         percpu_ref_get(&se_sess->cmd_count);
2771 out:
2772         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2773 
2774         if (ret && ack_kref)
2775                 target_put_sess_cmd(se_cmd);
2776 
2777         return ret;
2778 }
2779 EXPORT_SYMBOL(target_get_sess_cmd);
2780 
2781 static void target_free_cmd_mem(struct se_cmd *cmd)
2782 {
2783         transport_free_pages(cmd);
2784 
2785         if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2786                 core_tmr_release_req(cmd->se_tmr_req);
2787         if (cmd->t_task_cdb != cmd->__t_task_cdb)
2788                 kfree(cmd->t_task_cdb);
2789 }
2790 
2791 static void target_release_cmd_kref(struct kref *kref)
2792 {
2793         struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2794         struct se_session *se_sess = se_cmd->se_sess;
2795         struct completion *free_compl = se_cmd->free_compl;
2796         struct completion *abrt_compl = se_cmd->abrt_compl;
2797         unsigned long flags;
2798 
2799         if (se_sess) {
2800                 spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2801                 list_del_init(&se_cmd->se_cmd_list);
2802                 spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2803         }
2804 
2805         target_free_cmd_mem(se_cmd);
2806         se_cmd->se_tfo->release_cmd(se_cmd);
2807         if (free_compl)
2808                 complete(free_compl);
2809         if (abrt_compl)
2810                 complete(abrt_compl);
2811 
2812         percpu_ref_put(&se_sess->cmd_count);
2813 }
2814 
2815 /**
2816  * target_put_sess_cmd - decrease the command reference count
2817  * @se_cmd:     command to drop a reference from
2818  *
2819  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2820  * refcount to drop to zero. Returns zero otherwise.
2821  */
2822 int target_put_sess_cmd(struct se_cmd *se_cmd)
2823 {
2824         return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2825 }
2826 EXPORT_SYMBOL(target_put_sess_cmd);
2827 
2828 static const char *data_dir_name(enum dma_data_direction d)
2829 {
2830         switch (d) {
2831         case DMA_BIDIRECTIONAL: return "BIDI";
2832         case DMA_TO_DEVICE:     return "WRITE";
2833         case DMA_FROM_DEVICE:   return "READ";
2834         case DMA_NONE:          return "NONE";
2835         }
2836 
2837         return "(?)";
2838 }
2839 
2840 static const char *cmd_state_name(enum transport_state_table t)
2841 {
2842         switch (t) {
2843         case TRANSPORT_NO_STATE:        return "NO_STATE";
2844         case TRANSPORT_NEW_CMD:         return "NEW_CMD";
2845         case TRANSPORT_WRITE_PENDING:   return "WRITE_PENDING";
2846         case TRANSPORT_PROCESSING:      return "PROCESSING";
2847         case TRANSPORT_COMPLETE:        return "COMPLETE";
2848         case TRANSPORT_ISTATE_PROCESSING:
2849                                         return "ISTATE_PROCESSING";
2850         case TRANSPORT_COMPLETE_QF_WP:  return "COMPLETE_QF_WP";
2851         case TRANSPORT_COMPLETE_QF_OK:  return "COMPLETE_QF_OK";
2852         case TRANSPORT_COMPLETE_QF_ERR: return "COMPLETE_QF_ERR";
2853         }
2854 
2855         return "(?)";
2856 }
2857 
2858 static void target_append_str(char **str, const char *txt)
2859 {
2860         char *prev = *str;
2861 
2862         *str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
2863                 kstrdup(txt, GFP_ATOMIC);
2864         kfree(prev);
2865 }
2866 
2867 /*
2868  * Convert a transport state bitmask into a string. The caller is
2869  * responsible for freeing the returned pointer.
2870  */
2871 static char *target_ts_to_str(u32 ts)
2872 {
2873         char *str = NULL;
2874 
2875         if (ts & CMD_T_ABORTED)
2876                 target_append_str(&str, "aborted");
2877         if (ts & CMD_T_ACTIVE)
2878                 target_append_str(&str, "active");
2879         if (ts & CMD_T_COMPLETE)
2880                 target_append_str(&str, "complete");
2881         if (ts & CMD_T_SENT)
2882                 target_append_str(&str, "sent");
2883         if (ts & CMD_T_STOP)
2884                 target_append_str(&str, "stop");
2885         if (ts & CMD_T_FABRIC_STOP)
2886                 target_append_str(&str, "fabric_stop");
2887 
2888         return str;
2889 }
2890 
2891 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
2892 {
2893         switch (tmf) {
2894         case TMR_ABORT_TASK:            return "ABORT_TASK";
2895         case TMR_ABORT_TASK_SET:        return "ABORT_TASK_SET";
2896         case TMR_CLEAR_ACA:             return "CLEAR_ACA";
2897         case TMR_CLEAR_TASK_SET:        return "CLEAR_TASK_SET";
2898         case TMR_LUN_RESET:             return "LUN_RESET";
2899         case TMR_TARGET_WARM_RESET:     return "TARGET_WARM_RESET";
2900         case TMR_TARGET_COLD_RESET:     return "TARGET_COLD_RESET";
2901         case TMR_UNKNOWN:               break;
2902         }
2903         return "(?)";
2904 }
2905 
2906 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
2907 {
2908         char *ts_str = target_ts_to_str(cmd->transport_state);
2909         const u8 *cdb = cmd->t_task_cdb;
2910         struct se_tmr_req *tmf = cmd->se_tmr_req;
2911 
2912         if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2913                 pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
2914                          pfx, cdb[0], cdb[1], cmd->tag,
2915                          data_dir_name(cmd->data_direction),
2916                          cmd->se_tfo->get_cmd_state(cmd),
2917                          cmd_state_name(cmd->t_state), cmd->data_length,
2918                          kref_read(&cmd->cmd_kref), ts_str);
2919         } else {
2920                 pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
2921                          pfx, target_tmf_name(tmf->function), cmd->tag,
2922                          tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
2923                          cmd_state_name(cmd->t_state),
2924                          kref_read(&cmd->cmd_kref), ts_str);
2925         }
2926         kfree(ts_str);
2927 }
2928 EXPORT_SYMBOL(target_show_cmd);
2929 
2930 /**
2931  * target_sess_cmd_list_set_waiting - Set sess_tearing_down so no new commands are queued.
2932  * @se_sess:    session to flag
2933  */
2934 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2935 {
2936         unsigned long flags;
2937 
2938         spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2939         se_sess->sess_tearing_down = 1;
2940         spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2941 
2942         percpu_ref_kill(&se_sess->cmd_count);
2943 }
2944 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2945 
2946 /**
2947  * target_wait_for_sess_cmds - Wait for outstanding commands
2948  * @se_sess:    session to wait for active I/O
2949  */
2950 void target_wait_for_sess_cmds(struct se_session *se_sess)
2951 {
2952         struct se_cmd *cmd;
2953         int ret;
2954 
2955         WARN_ON_ONCE(!se_sess->sess_tearing_down);
2956 
2957         do {
2958                 ret = wait_event_timeout(se_sess->cmd_list_wq,
2959                                 percpu_ref_is_zero(&se_sess->cmd_count),
2960                                 180 * HZ);
2961                 list_for_each_entry(cmd, &se_sess->sess_cmd_list, se_cmd_list)
2962                         target_show_cmd("session shutdown: still waiting for ",
2963                                         cmd);
2964         } while (ret <= 0);
2965 }
2966 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2967 
2968 /*
2969  * Prevent that new percpu_ref_tryget_live() calls succeed and wait until
2970  * all references to the LUN have been released. Called during LUN shutdown.
2971  */
2972 void transport_clear_lun_ref(struct se_lun *lun)
2973 {
2974         percpu_ref_kill(&lun->lun_ref);
2975         wait_for_completion(&lun->lun_shutdown_comp);
2976 }
2977 
2978 static bool
2979 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2980                            bool *aborted, bool *tas, unsigned long *flags)
2981         __releases(&cmd->t_state_lock)
2982         __acquires(&cmd->t_state_lock)
2983 {
2984 
2985         assert_spin_locked(&cmd->t_state_lock);
2986         WARN_ON_ONCE(!irqs_disabled());
2987 
2988         if (fabric_stop)
2989                 cmd->transport_state |= CMD_T_FABRIC_STOP;
2990 
2991         if (cmd->transport_state & CMD_T_ABORTED)
2992                 *aborted = true;
2993 
2994         if (cmd->transport_state & CMD_T_TAS)
2995                 *tas = true;
2996 
2997         if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2998             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2999                 return false;
3000 
3001         if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
3002             !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3003                 return false;
3004 
3005         if (!(cmd->transport_state & CMD_T_ACTIVE))
3006                 return false;
3007 
3008         if (fabric_stop && *aborted)
3009                 return false;
3010 
3011         cmd->transport_state |= CMD_T_STOP;
3012 
3013         target_show_cmd("wait_for_tasks: Stopping ", cmd);
3014 
3015         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
3016 
3017         while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
3018                                             180 * HZ))
3019                 target_show_cmd("wait for tasks: ", cmd);
3020 
3021         spin_lock_irqsave(&cmd->t_state_lock, *flags);
3022         cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
3023 
3024         pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
3025                  "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
3026 
3027         return true;
3028 }
3029 
3030 /**
3031  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3032  * @cmd: command to wait on
3033  */
3034 bool transport_wait_for_tasks(struct se_cmd *cmd)
3035 {
3036         unsigned long flags;
3037         bool ret, aborted = false, tas = false;
3038 
3039         spin_lock_irqsave(&cmd->t_state_lock, flags);
3040         ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3041         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3042 
3043         return ret;
3044 }
3045 EXPORT_SYMBOL(transport_wait_for_tasks);
3046 
3047 struct sense_info {
3048         u8 key;
3049         u8 asc;
3050         u8 ascq;
3051         bool add_sector_info;
3052 };
3053 
3054 static const struct sense_info sense_info_table[] = {
3055         [TCM_NO_SENSE] = {
3056                 .key = NOT_READY
3057         },
3058         [TCM_NON_EXISTENT_LUN] = {
3059                 .key = ILLEGAL_REQUEST,
3060                 .asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3061         },
3062         [TCM_UNSUPPORTED_SCSI_OPCODE] = {
3063                 .key = ILLEGAL_REQUEST,
3064                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3065         },
3066         [TCM_SECTOR_COUNT_TOO_MANY] = {
3067                 .key = ILLEGAL_REQUEST,
3068                 .asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3069         },
3070         [TCM_UNKNOWN_MODE_PAGE] = {
3071                 .key = ILLEGAL_REQUEST,
3072                 .asc = 0x24, /* INVALID FIELD IN CDB */
3073         },
3074         [TCM_CHECK_CONDITION_ABORT_CMD] = {
3075                 .key = ABORTED_COMMAND,
3076                 .asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3077                 .ascq = 0x03,
3078         },
3079         [TCM_INCORRECT_AMOUNT_OF_DATA] = {
3080                 .key = ABORTED_COMMAND,
3081                 .asc = 0x0c, /* WRITE ERROR */
3082                 .ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3083         },
3084         [TCM_INVALID_CDB_FIELD] = {
3085                 .key = ILLEGAL_REQUEST,
3086                 .asc = 0x24, /* INVALID FIELD IN CDB */
3087         },
3088         [TCM_INVALID_PARAMETER_LIST] = {
3089                 .key = ILLEGAL_REQUEST,
3090                 .asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3091         },
3092         [TCM_TOO_MANY_TARGET_DESCS] = {
3093                 .key = ILLEGAL_REQUEST,
3094                 .asc = 0x26,
3095                 .ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3096         },
3097         [TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3098                 .key = ILLEGAL_REQUEST,
3099                 .asc = 0x26,
3100                 .ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3101         },
3102         [TCM_TOO_MANY_SEGMENT_DESCS] = {
3103                 .key = ILLEGAL_REQUEST,
3104                 .asc = 0x26,
3105                 .ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3106         },
3107         [TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3108                 .key = ILLEGAL_REQUEST,
3109                 .asc = 0x26,
3110                 .ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3111         },
3112         [TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3113                 .key = ILLEGAL_REQUEST,
3114                 .asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3115         },
3116         [TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3117                 .key = ILLEGAL_REQUEST,
3118                 .asc = 0x0c, /* WRITE ERROR */
3119                 .ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3120         },
3121         [TCM_SERVICE_CRC_ERROR] = {
3122                 .key = ABORTED_COMMAND,
3123                 .asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3124                 .ascq = 0x05, /* N/A */
3125         },
3126         [TCM_SNACK_REJECTED] = {
3127                 .key = ABORTED_COMMAND,
3128                 .asc = 0x11, /* READ ERROR */
3129                 .ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3130         },
3131         [TCM_WRITE_PROTECTED] = {
3132                 .key = DATA_PROTECT,
3133                 .asc = 0x27, /* WRITE PROTECTED */
3134         },
3135         [TCM_ADDRESS_OUT_OF_RANGE] = {
3136                 .key = ILLEGAL_REQUEST,
3137                 .asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3138         },
3139         [TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3140                 .key = UNIT_ATTENTION,
3141         },
3142         [TCM_CHECK_CONDITION_NOT_READY] = {
3143                 .key = NOT_READY,
3144         },
3145         [TCM_MISCOMPARE_VERIFY] = {
3146                 .key = MISCOMPARE,
3147                 .asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3148                 .ascq = 0x00,
3149         },
3150         [TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3151                 .key = ABORTED_COMMAND,
3152                 .asc = 0x10,
3153                 .ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3154                 .add_sector_info = true,
3155         },
3156         [TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3157                 .key = ABORTED_COMMAND,
3158                 .asc = 0x10,
3159                 .ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3160                 .add_sector_info = true,
3161         },
3162         [TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3163                 .key = ABORTED_COMMAND,
3164                 .asc = 0x10,
3165                 .ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3166                 .add_sector_info = true,
3167         },
3168         [TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3169                 .key = COPY_ABORTED,
3170                 .asc = 0x0d,
3171                 .ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3172 
3173         },
3174         [TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3175                 /*
3176                  * Returning ILLEGAL REQUEST would cause immediate IO errors on
3177                  * Solaris initiators.  Returning NOT READY instead means the
3178                  * operations will be retried a finite number of times and we
3179                  * can survive intermittent errors.
3180                  */
3181                 .key = NOT_READY,
3182                 .asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3183         },
3184         [TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3185                 /*
3186                  * From spc4r22 section5.7.7,5.7.8
3187                  * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3188                  * or a REGISTER AND IGNORE EXISTING KEY service action or
3189                  * REGISTER AND MOVE service actionis attempted,
3190                  * but there are insufficient device server resources to complete the
3191                  * operation, then the command shall be terminated with CHECK CONDITION
3192                  * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3193                  * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3194                  */
3195                 .key = ILLEGAL_REQUEST,
3196                 .asc = 0x55,
3197                 .ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3198         },
3199 };
3200 
3201 /**
3202  * translate_sense_reason - translate a sense reason into T10 key, asc and ascq
3203  * @cmd: SCSI command in which the resulting sense buffer or SCSI status will
3204  *   be stored.
3205  * @reason: LIO sense reason code. If this argument has the value
3206  *   TCM_CHECK_CONDITION_UNIT_ATTENTION, try to dequeue a unit attention. If
3207  *   dequeuing a unit attention fails due to multiple commands being processed
3208  *   concurrently, set the command status to BUSY.
3209  *
3210  * Return: 0 upon success or -EINVAL if the sense buffer is too small.
3211  */
3212 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3213 {
3214         const struct sense_info *si;
3215         u8 *buffer = cmd->sense_buffer;
3216         int r = (__force int)reason;
3217         u8 key, asc, ascq;
3218         bool desc_format = target_sense_desc_format(cmd->se_dev);
3219 
3220         if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
3221                 si = &sense_info_table[r];
3222         else
3223                 si = &sense_info_table[(__force int)
3224                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3225 
3226         key = si->key;
3227         if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3228                 if (!core_scsi3_ua_for_check_condition(cmd, &key, &asc,
3229                                                        &ascq)) {
3230                         cmd->scsi_status = SAM_STAT_BUSY;
3231                         return;
3232                 }
3233         } else if (si->asc == 0) {
3234                 WARN_ON_ONCE(cmd->scsi_asc == 0);
3235                 asc = cmd->scsi_asc;
3236                 ascq = cmd->scsi_ascq;
3237         } else {
3238                 asc = si->asc;
3239                 ascq = si->ascq;
3240         }
3241 
3242         cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3243         cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3244         cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3245         scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
3246         if (si->add_sector_info)
3247                 WARN_ON_ONCE(scsi_set_sense_information(buffer,
3248                                                         cmd->scsi_sense_length,
3249                                                         cmd->bad_sector) < 0);
3250 }
3251 
3252 int
3253 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3254                 sense_reason_t reason, int from_transport)
3255 {
3256         unsigned long flags;
3257 
3258         WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3259 
3260         spin_lock_irqsave(&cmd->t_state_lock, flags);
3261         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3262                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3263                 return 0;
3264         }
3265         cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3266         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3267 
3268         if (!from_transport)
3269                 translate_sense_reason(cmd, reason);
3270 
3271         trace_target_cmd_complete(cmd);
3272         return cmd->se_tfo->queue_status(cmd);
3273 }
3274 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3275 
3276 /**
3277  * target_send_busy - Send SCSI BUSY status back to the initiator
3278  * @cmd: SCSI command for which to send a BUSY reply.
3279  *
3280  * Note: Only call this function if target_submit_cmd*() failed.
3281  */
3282 int target_send_busy(struct se_cmd *cmd)
3283 {
3284         WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3285 
3286         cmd->scsi_status = SAM_STAT_BUSY;
3287         trace_target_cmd_complete(cmd);
3288         return cmd->se_tfo->queue_status(cmd);
3289 }
3290 EXPORT_SYMBOL(target_send_busy);
3291 
3292 static void target_tmr_work(struct work_struct *work)
3293 {
3294         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3295         struct se_device *dev = cmd->se_dev;
3296         struct se_tmr_req *tmr = cmd->se_tmr_req;
3297         int ret;
3298 
3299         if (cmd->transport_state & CMD_T_ABORTED)
3300                 goto aborted;
3301 
3302         switch (tmr->function) {
3303         case TMR_ABORT_TASK:
3304                 core_tmr_abort_task(dev, tmr, cmd->se_sess);
3305                 break;
3306         case TMR_ABORT_TASK_SET:
3307         case TMR_CLEAR_ACA:
3308         case TMR_CLEAR_TASK_SET:
3309                 tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3310                 break;
3311         case TMR_LUN_RESET:
3312                 ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3313                 tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3314                                          TMR_FUNCTION_REJECTED;
3315                 if (tmr->response == TMR_FUNCTION_COMPLETE) {
3316                         target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3317                                                cmd->orig_fe_lun, 0x29,
3318                                                ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3319                 }
3320                 break;
3321         case TMR_TARGET_WARM_RESET:
3322                 tmr->response = TMR_FUNCTION_REJECTED;
3323                 break;
3324         case TMR_TARGET_COLD_RESET:
3325                 tmr->response = TMR_FUNCTION_REJECTED;
3326                 break;
3327         default:
3328                 pr_err("Unknown TMR function: 0x%02x.\n",
3329                                 tmr->function);
3330                 tmr->response = TMR_FUNCTION_REJECTED;
3331                 break;
3332         }
3333 
3334         if (cmd->transport_state & CMD_T_ABORTED)
3335                 goto aborted;
3336 
3337         cmd->se_tfo->queue_tm_rsp(cmd);
3338 
3339         transport_lun_remove_cmd(cmd);
3340         transport_cmd_check_stop_to_fabric(cmd);
3341         return;
3342 
3343 aborted:
3344         target_handle_abort(cmd);
3345 }
3346 
3347 int transport_generic_handle_tmr(
3348         struct se_cmd *cmd)
3349 {
3350         unsigned long flags;
3351         bool aborted = false;
3352 
3353         spin_lock_irqsave(&cmd->t_state_lock, flags);
3354         if (cmd->transport_state & CMD_T_ABORTED) {
3355                 aborted = true;
3356         } else {
3357                 cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3358                 cmd->transport_state |= CMD_T_ACTIVE;
3359         }
3360         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3361 
3362         if (aborted) {
3363                 pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d ref_tag: %llu tag: %llu\n",
3364                                     cmd->se_tmr_req->function,
3365                                     cmd->se_tmr_req->ref_task_tag, cmd->tag);
3366                 target_handle_abort(cmd);
3367                 return 0;
3368         }
3369 
3370         INIT_WORK(&cmd->work, target_tmr_work);
3371         schedule_work(&cmd->work);
3372         return 0;
3373 }
3374 EXPORT_SYMBOL(transport_generic_handle_tmr);
3375 
3376 bool
3377 target_check_wce(struct se_device *dev)
3378 {
3379         bool wce = false;
3380 
3381         if (dev->transport->get_write_cache)
3382                 wce = dev->transport->get_write_cache(dev);
3383         else if (dev->dev_attrib.emulate_write_cache > 0)
3384                 wce = true;
3385 
3386         return wce;
3387 }
3388 
3389 bool
3390 target_check_fua(struct se_device *dev)
3391 {
3392         return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3393 }