drivers/target/target_core

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This source file includes following definitions.
target_emulate_report_referrals
target_emulate_report_target_port_groups
target_emulate_set_target_port_groups
set_ascq
core_alua_state_nonoptimized
core_alua_state_lba_dependent
core_alua_state_standby
core_alua_state_unavailable
core_alua_state_transition
target_alua_state_check
core_alua_check_transition
core_alua_dump_state
core_alua_dump_status
core_alua_check_nonop_delay
core_alua_write_tpg_metadata
core_alua_update_tpg_primary_metadata
core_alua_queue_state_change_ua
core_alua_do_transition_tg_pt
core_alua_do_port_transition
core_alua_update_tpg_secondary_metadata
core_alua_set_tg_pt_secondary_state
core_alua_allocate_lba_map
core_alua_allocate_lba_map_mem
core_alua_free_lba_map
core_alua_set_lba_map
core_alua_allocate_lu_gp
core_alua_set_lu_gp_id
core_alua_allocate_lu_gp_mem
core_alua_free_lu_gp
core_alua_free_lu_gp_mem
core_alua_get_lu_gp_by_name
core_alua_put_lu_gp_from_name
__core_alua_attach_lu_gp_mem
__core_alua_drop_lu_gp_mem
core_alua_allocate_tg_pt_gp
core_alua_set_tg_pt_gp_id
core_alua_free_tg_pt_gp
core_alua_get_tg_pt_gp_by_name
core_alua_put_tg_pt_gp_from_name
__target_attach_tg_pt_gp
target_attach_tg_pt_gp
__target_detach_tg_pt_gp
target_detach_tg_pt_gp
core_alua_show_tg_pt_gp_info
core_alua_store_tg_pt_gp_info
core_alua_show_access_type
core_alua_store_access_type
core_alua_show_nonop_delay_msecs
core_alua_store_nonop_delay_msecs
core_alua_show_trans_delay_msecs
core_alua_store_trans_delay_msecs
core_alua_show_implicit_trans_secs
core_alua_store_implicit_trans_secs
core_alua_show_preferred_bit
core_alua_store_preferred_bit
core_alua_show_offline_bit
core_alua_store_offline_bit
core_alua_show_secondary_status
core_alua_store_secondary_status
core_alua_show_secondary_write_metadata
core_alua_store_secondary_write_metadata
core_setup_alua
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * Filename:  target_core_alua.c
   4  *
   5  * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
   6  *
   7  * (c) Copyright 2009-2013 Datera, Inc.
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  ******************************************************************************/
  12 
  13 #include <linux/slab.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/configfs.h>
  16 #include <linux/delay.h>
  17 #include <linux/export.h>
  18 #include <linux/fcntl.h>
  19 #include <linux/file.h>
  20 #include <linux/fs.h>
  21 #include <scsi/scsi_proto.h>
  22 #include <asm/unaligned.h>
  23 
  24 #include <target/target_core_base.h>
  25 #include <target/target_core_backend.h>
  26 #include <target/target_core_fabric.h>
  27 
  28 #include "target_core_internal.h"
  29 #include "target_core_alua.h"
  30 #include "target_core_ua.h"
  31 
  32 static sense_reason_t core_alua_check_transition(int state, int valid,
  33                                                  int *primary, int explicit);
  34 static int core_alua_set_tg_pt_secondary_state(
  35                 struct se_lun *lun, int explicit, int offline);
  36 
  37 static char *core_alua_dump_state(int state);
  38 
  39 static void __target_attach_tg_pt_gp(struct se_lun *lun,
  40                 struct t10_alua_tg_pt_gp *tg_pt_gp);
  41 
  42 static u16 alua_lu_gps_counter;
  43 static u32 alua_lu_gps_count;
  44 
  45 static DEFINE_SPINLOCK(lu_gps_lock);
  46 static LIST_HEAD(lu_gps_list);
  47 
  48 struct t10_alua_lu_gp *default_lu_gp;
  49 
  50 /*
  51  * REPORT REFERRALS
  52  *
  53  * See sbc3r35 section 5.23
  54  */
  55 sense_reason_t
  56 target_emulate_report_referrals(struct se_cmd *cmd)
  57 {
  58         struct se_device *dev = cmd->se_dev;
  59         struct t10_alua_lba_map *map;
  60         struct t10_alua_lba_map_member *map_mem;
  61         unsigned char *buf;
  62         u32 rd_len = 0, off;
  63 
  64         if (cmd->data_length < 4) {
  65                 pr_warn("REPORT REFERRALS allocation length %u too"
  66                         " small\n", cmd->data_length);
  67                 return TCM_INVALID_CDB_FIELD;
  68         }
  69 
  70         buf = transport_kmap_data_sg(cmd);
  71         if (!buf)
  72                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
  73 
  74         off = 4;
  75         spin_lock(&dev->t10_alua.lba_map_lock);
  76         if (list_empty(&dev->t10_alua.lba_map_list)) {
  77                 spin_unlock(&dev->t10_alua.lba_map_lock);
  78                 transport_kunmap_data_sg(cmd);
  79 
  80                 return TCM_UNSUPPORTED_SCSI_OPCODE;
  81         }
  82 
  83         list_for_each_entry(map, &dev->t10_alua.lba_map_list,
  84                             lba_map_list) {
  85                 int desc_num = off + 3;
  86                 int pg_num;
  87 
  88                 off += 4;
  89                 if (cmd->data_length > off)
  90                         put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
  91                 off += 8;
  92                 if (cmd->data_length > off)
  93                         put_unaligned_be64(map->lba_map_last_lba, &buf[off]);
  94                 off += 8;
  95                 rd_len += 20;
  96                 pg_num = 0;
  97                 list_for_each_entry(map_mem, &map->lba_map_mem_list,
  98                                     lba_map_mem_list) {
  99                         int alua_state = map_mem->lba_map_mem_alua_state;
 100                         int alua_pg_id = map_mem->lba_map_mem_alua_pg_id;
 101 
 102                         if (cmd->data_length > off)
 103                                 buf[off] = alua_state & 0x0f;
 104                         off += 2;
 105                         if (cmd->data_length > off)
 106                                 buf[off] = (alua_pg_id >> 8) & 0xff;
 107                         off++;
 108                         if (cmd->data_length > off)
 109                                 buf[off] = (alua_pg_id & 0xff);
 110                         off++;
 111                         rd_len += 4;
 112                         pg_num++;
 113                 }
 114                 if (cmd->data_length > desc_num)
 115                         buf[desc_num] = pg_num;
 116         }
 117         spin_unlock(&dev->t10_alua.lba_map_lock);
 118 
 119         /*
 120          * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 121          */
 122         put_unaligned_be16(rd_len, &buf[2]);
 123 
 124         transport_kunmap_data_sg(cmd);
 125 
 126         target_complete_cmd(cmd, GOOD);
 127         return 0;
 128 }
 129 
 130 /*
 131  * REPORT_TARGET_PORT_GROUPS
 132  *
 133  * See spc4r17 section 6.27
 134  */
 135 sense_reason_t
 136 target_emulate_report_target_port_groups(struct se_cmd *cmd)
 137 {
 138         struct se_device *dev = cmd->se_dev;
 139         struct t10_alua_tg_pt_gp *tg_pt_gp;
 140         struct se_lun *lun;
 141         unsigned char *buf;
 142         u32 rd_len = 0, off;
 143         int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
 144 
 145         /*
 146          * Skip over RESERVED area to first Target port group descriptor
 147          * depending on the PARAMETER DATA FORMAT type..
 148          */
 149         if (ext_hdr != 0)
 150                 off = 8;
 151         else
 152                 off = 4;
 153 
 154         if (cmd->data_length < off) {
 155                 pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
 156                         " small for %s header\n", cmd->data_length,
 157                         (ext_hdr) ? "extended" : "normal");
 158                 return TCM_INVALID_CDB_FIELD;
 159         }
 160         buf = transport_kmap_data_sg(cmd);
 161         if (!buf)
 162                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 163 
 164         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
 165         list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
 166                         tg_pt_gp_list) {
 167                 /*
 168                  * Check if the Target port group and Target port descriptor list
 169                  * based on tg_pt_gp_members count will fit into the response payload.
 170                  * Otherwise, bump rd_len to let the initiator know we have exceeded
 171                  * the allocation length and the response is truncated.
 172                  */
 173                 if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
 174                      cmd->data_length) {
 175                         rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
 176                         continue;
 177                 }
 178                 /*
 179                  * PREF: Preferred target port bit, determine if this
 180                  * bit should be set for port group.
 181                  */
 182                 if (tg_pt_gp->tg_pt_gp_pref)
 183                         buf[off] = 0x80;
 184                 /*
 185                  * Set the ASYMMETRIC ACCESS State
 186                  */
 187                 buf[off++] |= tg_pt_gp->tg_pt_gp_alua_access_state & 0xff;
 188                 /*
 189                  * Set supported ASYMMETRIC ACCESS State bits
 190                  */
 191                 buf[off++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
 192                 /*
 193                  * TARGET PORT GROUP
 194                  */
 195                 put_unaligned_be16(tg_pt_gp->tg_pt_gp_id, &buf[off]);
 196                 off += 2;
 197 
 198                 off++; /* Skip over Reserved */
 199                 /*
 200                  * STATUS CODE
 201                  */
 202                 buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
 203                 /*
 204                  * Vendor Specific field
 205                  */
 206                 buf[off++] = 0x00;
 207                 /*
 208                  * TARGET PORT COUNT
 209                  */
 210                 buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
 211                 rd_len += 8;
 212 
 213                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 214                 list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
 215                                 lun_tg_pt_gp_link) {
 216                         /*
 217                          * Start Target Port descriptor format
 218                          *
 219                          * See spc4r17 section 6.2.7 Table 247
 220                          */
 221                         off += 2; /* Skip over Obsolete */
 222                         /*
 223                          * Set RELATIVE TARGET PORT IDENTIFIER
 224                          */
 225                         put_unaligned_be16(lun->lun_rtpi, &buf[off]);
 226                         off += 2;
 227                         rd_len += 4;
 228                 }
 229                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 230         }
 231         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 232         /*
 233          * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 234          */
 235         put_unaligned_be32(rd_len, &buf[0]);
 236 
 237         /*
 238          * Fill in the Extended header parameter data format if requested
 239          */
 240         if (ext_hdr != 0) {
 241                 buf[4] = 0x10;
 242                 /*
 243                  * Set the implicit transition time (in seconds) for the application
 244                  * client to use as a base for it's transition timeout value.
 245                  *
 246                  * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
 247                  * this CDB was received upon to determine this value individually
 248                  * for ALUA target port group.
 249                  */
 250                 spin_lock(&cmd->se_lun->lun_tg_pt_gp_lock);
 251                 tg_pt_gp = cmd->se_lun->lun_tg_pt_gp;
 252                 if (tg_pt_gp)
 253                         buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
 254                 spin_unlock(&cmd->se_lun->lun_tg_pt_gp_lock);
 255         }
 256         transport_kunmap_data_sg(cmd);
 257 
 258         target_complete_cmd_with_length(cmd, GOOD, rd_len + 4);
 259         return 0;
 260 }
 261 
 262 /*
 263  * SET_TARGET_PORT_GROUPS for explicit ALUA operation.
 264  *
 265  * See spc4r17 section 6.35
 266  */
 267 sense_reason_t
 268 target_emulate_set_target_port_groups(struct se_cmd *cmd)
 269 {
 270         struct se_device *dev = cmd->se_dev;
 271         struct se_lun *l_lun = cmd->se_lun;
 272         struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
 273         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
 274         unsigned char *buf;
 275         unsigned char *ptr;
 276         sense_reason_t rc = TCM_NO_SENSE;
 277         u32 len = 4; /* Skip over RESERVED area in header */
 278         int alua_access_state, primary = 0, valid_states;
 279         u16 tg_pt_id, rtpi;
 280 
 281         if (cmd->data_length < 4) {
 282                 pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
 283                         " small\n", cmd->data_length);
 284                 return TCM_INVALID_PARAMETER_LIST;
 285         }
 286 
 287         buf = transport_kmap_data_sg(cmd);
 288         if (!buf)
 289                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 290 
 291         /*
 292          * Determine if explicit ALUA via SET_TARGET_PORT_GROUPS is allowed
 293          * for the local tg_pt_gp.
 294          */
 295         spin_lock(&l_lun->lun_tg_pt_gp_lock);
 296         l_tg_pt_gp = l_lun->lun_tg_pt_gp;
 297         if (!l_tg_pt_gp) {
 298                 spin_unlock(&l_lun->lun_tg_pt_gp_lock);
 299                 pr_err("Unable to access l_lun->tg_pt_gp\n");
 300                 rc = TCM_UNSUPPORTED_SCSI_OPCODE;
 301                 goto out;
 302         }
 303 
 304         if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
 305                 spin_unlock(&l_lun->lun_tg_pt_gp_lock);
 306                 pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
 307                                 " while TPGS_EXPLICIT_ALUA is disabled\n");
 308                 rc = TCM_UNSUPPORTED_SCSI_OPCODE;
 309                 goto out;
 310         }
 311         valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
 312         spin_unlock(&l_lun->lun_tg_pt_gp_lock);
 313 
 314         ptr = &buf[4]; /* Skip over RESERVED area in header */
 315 
 316         while (len < cmd->data_length) {
 317                 bool found = false;
 318                 alua_access_state = (ptr[0] & 0x0f);
 319                 /*
 320                  * Check the received ALUA access state, and determine if
 321                  * the state is a primary or secondary target port asymmetric
 322                  * access state.
 323                  */
 324                 rc = core_alua_check_transition(alua_access_state, valid_states,
 325                                                 &primary, 1);
 326                 if (rc) {
 327                         /*
 328                          * If the SET TARGET PORT GROUPS attempts to establish
 329                          * an invalid combination of target port asymmetric
 330                          * access states or attempts to establish an
 331                          * unsupported target port asymmetric access state,
 332                          * then the command shall be terminated with CHECK
 333                          * CONDITION status, with the sense key set to ILLEGAL
 334                          * REQUEST, and the additional sense code set to INVALID
 335                          * FIELD IN PARAMETER LIST.
 336                          */
 337                         goto out;
 338                 }
 339 
 340                 /*
 341                  * If the ASYMMETRIC ACCESS STATE field (see table 267)
 342                  * specifies a primary target port asymmetric access state,
 343                  * then the TARGET PORT GROUP OR TARGET PORT field specifies
 344                  * a primary target port group for which the primary target
 345                  * port asymmetric access state shall be changed. If the
 346                  * ASYMMETRIC ACCESS STATE field specifies a secondary target
 347                  * port asymmetric access state, then the TARGET PORT GROUP OR
 348                  * TARGET PORT field specifies the relative target port
 349                  * identifier (see 3.1.120) of the target port for which the
 350                  * secondary target port asymmetric access state shall be
 351                  * changed.
 352                  */
 353                 if (primary) {
 354                         tg_pt_id = get_unaligned_be16(ptr + 2);
 355                         /*
 356                          * Locate the matching target port group ID from
 357                          * the global tg_pt_gp list
 358                          */
 359                         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
 360                         list_for_each_entry(tg_pt_gp,
 361                                         &dev->t10_alua.tg_pt_gps_list,
 362                                         tg_pt_gp_list) {
 363                                 if (!tg_pt_gp->tg_pt_gp_valid_id)
 364                                         continue;
 365 
 366                                 if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
 367                                         continue;
 368 
 369                                 atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
 370 
 371                                 spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 372 
 373                                 if (!core_alua_do_port_transition(tg_pt_gp,
 374                                                 dev, l_lun, nacl,
 375                                                 alua_access_state, 1))
 376                                         found = true;
 377 
 378                                 spin_lock(&dev->t10_alua.tg_pt_gps_lock);
 379                                 atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
 380                                 break;
 381                         }
 382                         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 383                 } else {
 384                         struct se_lun *lun;
 385 
 386                         /*
 387                          * Extract the RELATIVE TARGET PORT IDENTIFIER to identify
 388                          * the Target Port in question for the the incoming
 389                          * SET_TARGET_PORT_GROUPS op.
 390                          */
 391                         rtpi = get_unaligned_be16(ptr + 2);
 392                         /*
 393                          * Locate the matching relative target port identifier
 394                          * for the struct se_device storage object.
 395                          */
 396                         spin_lock(&dev->se_port_lock);
 397                         list_for_each_entry(lun, &dev->dev_sep_list,
 398                                                         lun_dev_link) {
 399                                 if (lun->lun_rtpi != rtpi)
 400                                         continue;
 401 
 402                                 // XXX: racy unlock
 403                                 spin_unlock(&dev->se_port_lock);
 404 
 405                                 if (!core_alua_set_tg_pt_secondary_state(
 406                                                 lun, 1, 1))
 407                                         found = true;
 408 
 409                                 spin_lock(&dev->se_port_lock);
 410                                 break;
 411                         }
 412                         spin_unlock(&dev->se_port_lock);
 413                 }
 414 
 415                 if (!found) {
 416                         rc = TCM_INVALID_PARAMETER_LIST;
 417                         goto out;
 418                 }
 419 
 420                 ptr += 4;
 421                 len += 4;
 422         }
 423 
 424 out:
 425         transport_kunmap_data_sg(cmd);
 426         if (!rc)
 427                 target_complete_cmd(cmd, GOOD);
 428         return rc;
 429 }
 430 
 431 static inline void set_ascq(struct se_cmd *cmd, u8 alua_ascq)
 432 {
 433         /*
 434          * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
 435          * The ALUA additional sense code qualifier (ASCQ) is determined
 436          * by the ALUA primary or secondary access state..
 437          */
 438         pr_debug("[%s]: ALUA TG Port not available, "
 439                 "SenseKey: NOT_READY, ASC/ASCQ: "
 440                 "0x04/0x%02x\n",
 441                 cmd->se_tfo->fabric_name, alua_ascq);
 442 
 443         cmd->scsi_asc = 0x04;
 444         cmd->scsi_ascq = alua_ascq;
 445 }
 446 
 447 static inline void core_alua_state_nonoptimized(
 448         struct se_cmd *cmd,
 449         unsigned char *cdb,
 450         int nonop_delay_msecs)
 451 {
 452         /*
 453          * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
 454          * later to determine if processing of this cmd needs to be
 455          * temporarily delayed for the Active/NonOptimized primary access state.
 456          */
 457         cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
 458         cmd->alua_nonop_delay = nonop_delay_msecs;
 459 }
 460 
 461 static inline int core_alua_state_lba_dependent(
 462         struct se_cmd *cmd,
 463         struct t10_alua_tg_pt_gp *tg_pt_gp)
 464 {
 465         struct se_device *dev = cmd->se_dev;
 466         u64 segment_size, segment_mult, sectors, lba;
 467 
 468         /* Only need to check for cdb actually containing LBAs */
 469         if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB))
 470                 return 0;
 471 
 472         spin_lock(&dev->t10_alua.lba_map_lock);
 473         segment_size = dev->t10_alua.lba_map_segment_size;
 474         segment_mult = dev->t10_alua.lba_map_segment_multiplier;
 475         sectors = cmd->data_length / dev->dev_attrib.block_size;
 476 
 477         lba = cmd->t_task_lba;
 478         while (lba < cmd->t_task_lba + sectors) {
 479                 struct t10_alua_lba_map *cur_map = NULL, *map;
 480                 struct t10_alua_lba_map_member *map_mem;
 481 
 482                 list_for_each_entry(map, &dev->t10_alua.lba_map_list,
 483                                     lba_map_list) {
 484                         u64 start_lba, last_lba;
 485                         u64 first_lba = map->lba_map_first_lba;
 486 
 487                         if (segment_mult) {
 488                                 u64 tmp = lba;
 489                                 start_lba = do_div(tmp, segment_size * segment_mult);
 490 
 491                                 last_lba = first_lba + segment_size - 1;
 492                                 if (start_lba >= first_lba &&
 493                                     start_lba <= last_lba) {
 494                                         lba += segment_size;
 495                                         cur_map = map;
 496                                         break;
 497                                 }
 498                         } else {
 499                                 last_lba = map->lba_map_last_lba;
 500                                 if (lba >= first_lba && lba <= last_lba) {
 501                                         lba = last_lba + 1;
 502                                         cur_map = map;
 503                                         break;
 504                                 }
 505                         }
 506                 }
 507                 if (!cur_map) {
 508                         spin_unlock(&dev->t10_alua.lba_map_lock);
 509                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
 510                         return 1;
 511                 }
 512                 list_for_each_entry(map_mem, &cur_map->lba_map_mem_list,
 513                                     lba_map_mem_list) {
 514                         if (map_mem->lba_map_mem_alua_pg_id !=
 515                             tg_pt_gp->tg_pt_gp_id)
 516                                 continue;
 517                         switch(map_mem->lba_map_mem_alua_state) {
 518                         case ALUA_ACCESS_STATE_STANDBY:
 519                                 spin_unlock(&dev->t10_alua.lba_map_lock);
 520                                 set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
 521                                 return 1;
 522                         case ALUA_ACCESS_STATE_UNAVAILABLE:
 523                                 spin_unlock(&dev->t10_alua.lba_map_lock);
 524                                 set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
 525                                 return 1;
 526                         default:
 527                                 break;
 528                         }
 529                 }
 530         }
 531         spin_unlock(&dev->t10_alua.lba_map_lock);
 532         return 0;
 533 }
 534 
 535 static inline int core_alua_state_standby(
 536         struct se_cmd *cmd,
 537         unsigned char *cdb)
 538 {
 539         /*
 540          * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
 541          * spc4r17 section 5.9.2.4.4
 542          */
 543         switch (cdb[0]) {
 544         case INQUIRY:
 545         case LOG_SELECT:
 546         case LOG_SENSE:
 547         case MODE_SELECT:
 548         case MODE_SENSE:
 549         case REPORT_LUNS:
 550         case RECEIVE_DIAGNOSTIC:
 551         case SEND_DIAGNOSTIC:
 552         case READ_CAPACITY:
 553                 return 0;
 554         case SERVICE_ACTION_IN_16:
 555                 switch (cdb[1] & 0x1f) {
 556                 case SAI_READ_CAPACITY_16:
 557                         return 0;
 558                 default:
 559                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
 560                         return 1;
 561                 }
 562         case MAINTENANCE_IN:
 563                 switch (cdb[1] & 0x1f) {
 564                 case MI_REPORT_TARGET_PGS:
 565                         return 0;
 566                 default:
 567                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
 568                         return 1;
 569                 }
 570         case MAINTENANCE_OUT:
 571                 switch (cdb[1]) {
 572                 case MO_SET_TARGET_PGS:
 573                         return 0;
 574                 default:
 575                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
 576                         return 1;
 577                 }
 578         case REQUEST_SENSE:
 579         case PERSISTENT_RESERVE_IN:
 580         case PERSISTENT_RESERVE_OUT:
 581         case READ_BUFFER:
 582         case WRITE_BUFFER:
 583                 return 0;
 584         default:
 585                 set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
 586                 return 1;
 587         }
 588 
 589         return 0;
 590 }
 591 
 592 static inline int core_alua_state_unavailable(
 593         struct se_cmd *cmd,
 594         unsigned char *cdb)
 595 {
 596         /*
 597          * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
 598          * spc4r17 section 5.9.2.4.5
 599          */
 600         switch (cdb[0]) {
 601         case INQUIRY:
 602         case REPORT_LUNS:
 603                 return 0;
 604         case MAINTENANCE_IN:
 605                 switch (cdb[1] & 0x1f) {
 606                 case MI_REPORT_TARGET_PGS:
 607                         return 0;
 608                 default:
 609                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
 610                         return 1;
 611                 }
 612         case MAINTENANCE_OUT:
 613                 switch (cdb[1]) {
 614                 case MO_SET_TARGET_PGS:
 615                         return 0;
 616                 default:
 617                         set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
 618                         return 1;
 619                 }
 620         case REQUEST_SENSE:
 621         case READ_BUFFER:
 622         case WRITE_BUFFER:
 623                 return 0;
 624         default:
 625                 set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
 626                 return 1;
 627         }
 628 
 629         return 0;
 630 }
 631 
 632 static inline int core_alua_state_transition(
 633         struct se_cmd *cmd,
 634         unsigned char *cdb)
 635 {
 636         /*
 637          * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
 638          * spc4r17 section 5.9.2.5
 639          */
 640         switch (cdb[0]) {
 641         case INQUIRY:
 642         case REPORT_LUNS:
 643                 return 0;
 644         case MAINTENANCE_IN:
 645                 switch (cdb[1] & 0x1f) {
 646                 case MI_REPORT_TARGET_PGS:
 647                         return 0;
 648                 default:
 649                         set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
 650                         return 1;
 651                 }
 652         case REQUEST_SENSE:
 653         case READ_BUFFER:
 654         case WRITE_BUFFER:
 655                 return 0;
 656         default:
 657                 set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
 658                 return 1;
 659         }
 660 
 661         return 0;
 662 }
 663 
 664 /*
 665  * return 1: Is used to signal LUN not accessible, and check condition/not ready
 666  * return 0: Used to signal success
 667  * return -1: Used to signal failure, and invalid cdb field
 668  */
 669 sense_reason_t
 670 target_alua_state_check(struct se_cmd *cmd)
 671 {
 672         struct se_device *dev = cmd->se_dev;
 673         unsigned char *cdb = cmd->t_task_cdb;
 674         struct se_lun *lun = cmd->se_lun;
 675         struct t10_alua_tg_pt_gp *tg_pt_gp;
 676         int out_alua_state, nonop_delay_msecs;
 677 
 678         if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
 679                 return 0;
 680         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
 681                 return 0;
 682 
 683         /*
 684          * First, check for a struct se_port specific secondary ALUA target port
 685          * access state: OFFLINE
 686          */
 687         if (atomic_read(&lun->lun_tg_pt_secondary_offline)) {
 688                 pr_debug("ALUA: Got secondary offline status for local"
 689                                 " target port\n");
 690                 set_ascq(cmd, ASCQ_04H_ALUA_OFFLINE);
 691                 return TCM_CHECK_CONDITION_NOT_READY;
 692         }
 693 
 694         if (!lun->lun_tg_pt_gp)
 695                 return 0;
 696 
 697         spin_lock(&lun->lun_tg_pt_gp_lock);
 698         tg_pt_gp = lun->lun_tg_pt_gp;
 699         out_alua_state = tg_pt_gp->tg_pt_gp_alua_access_state;
 700         nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
 701 
 702         // XXX: keeps using tg_pt_gp witout reference after unlock
 703         spin_unlock(&lun->lun_tg_pt_gp_lock);
 704         /*
 705          * Process ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED in a separate conditional
 706          * statement so the compiler knows explicitly to check this case first.
 707          * For the Optimized ALUA access state case, we want to process the
 708          * incoming fabric cmd ASAP..
 709          */
 710         if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED)
 711                 return 0;
 712 
 713         switch (out_alua_state) {
 714         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 715                 core_alua_state_nonoptimized(cmd, cdb, nonop_delay_msecs);
 716                 break;
 717         case ALUA_ACCESS_STATE_STANDBY:
 718                 if (core_alua_state_standby(cmd, cdb))
 719                         return TCM_CHECK_CONDITION_NOT_READY;
 720                 break;
 721         case ALUA_ACCESS_STATE_UNAVAILABLE:
 722                 if (core_alua_state_unavailable(cmd, cdb))
 723                         return TCM_CHECK_CONDITION_NOT_READY;
 724                 break;
 725         case ALUA_ACCESS_STATE_TRANSITION:
 726                 if (core_alua_state_transition(cmd, cdb))
 727                         return TCM_CHECK_CONDITION_NOT_READY;
 728                 break;
 729         case ALUA_ACCESS_STATE_LBA_DEPENDENT:
 730                 if (core_alua_state_lba_dependent(cmd, tg_pt_gp))
 731                         return TCM_CHECK_CONDITION_NOT_READY;
 732                 break;
 733         /*
 734          * OFFLINE is a secondary ALUA target port group access state, that is
 735          * handled above with struct se_lun->lun_tg_pt_secondary_offline=1
 736          */
 737         case ALUA_ACCESS_STATE_OFFLINE:
 738         default:
 739                 pr_err("Unknown ALUA access state: 0x%02x\n",
 740                                 out_alua_state);
 741                 return TCM_INVALID_CDB_FIELD;
 742         }
 743 
 744         return 0;
 745 }
 746 
 747 /*
 748  * Check implicit and explicit ALUA state change request.
 749  */
 750 static sense_reason_t
 751 core_alua_check_transition(int state, int valid, int *primary, int explicit)
 752 {
 753         /*
 754          * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
 755          * defined as primary target port asymmetric access states.
 756          */
 757         switch (state) {
 758         case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
 759                 if (!(valid & ALUA_AO_SUP))
 760                         goto not_supported;
 761                 *primary = 1;
 762                 break;
 763         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 764                 if (!(valid & ALUA_AN_SUP))
 765                         goto not_supported;
 766                 *primary = 1;
 767                 break;
 768         case ALUA_ACCESS_STATE_STANDBY:
 769                 if (!(valid & ALUA_S_SUP))
 770                         goto not_supported;
 771                 *primary = 1;
 772                 break;
 773         case ALUA_ACCESS_STATE_UNAVAILABLE:
 774                 if (!(valid & ALUA_U_SUP))
 775                         goto not_supported;
 776                 *primary = 1;
 777                 break;
 778         case ALUA_ACCESS_STATE_LBA_DEPENDENT:
 779                 if (!(valid & ALUA_LBD_SUP))
 780                         goto not_supported;
 781                 *primary = 1;
 782                 break;
 783         case ALUA_ACCESS_STATE_OFFLINE:
 784                 /*
 785                  * OFFLINE state is defined as a secondary target port
 786                  * asymmetric access state.
 787                  */
 788                 if (!(valid & ALUA_O_SUP))
 789                         goto not_supported;
 790                 *primary = 0;
 791                 break;
 792         case ALUA_ACCESS_STATE_TRANSITION:
 793                 if (!(valid & ALUA_T_SUP) || explicit)
 794                         /*
 795                          * Transitioning is set internally and by tcmu daemon,
 796                          * and cannot be selected through a STPG.
 797                          */
 798                         goto not_supported;
 799                 *primary = 0;
 800                 break;
 801         default:
 802                 pr_err("Unknown ALUA access state: 0x%02x\n", state);
 803                 return TCM_INVALID_PARAMETER_LIST;
 804         }
 805 
 806         return 0;
 807 
 808 not_supported:
 809         pr_err("ALUA access state %s not supported",
 810                core_alua_dump_state(state));
 811         return TCM_INVALID_PARAMETER_LIST;
 812 }
 813 
 814 static char *core_alua_dump_state(int state)
 815 {
 816         switch (state) {
 817         case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
 818                 return "Active/Optimized";
 819         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 820                 return "Active/NonOptimized";
 821         case ALUA_ACCESS_STATE_LBA_DEPENDENT:
 822                 return "LBA Dependent";
 823         case ALUA_ACCESS_STATE_STANDBY:
 824                 return "Standby";
 825         case ALUA_ACCESS_STATE_UNAVAILABLE:
 826                 return "Unavailable";
 827         case ALUA_ACCESS_STATE_OFFLINE:
 828                 return "Offline";
 829         case ALUA_ACCESS_STATE_TRANSITION:
 830                 return "Transitioning";
 831         default:
 832                 return "Unknown";
 833         }
 834 
 835         return NULL;
 836 }
 837 
 838 char *core_alua_dump_status(int status)
 839 {
 840         switch (status) {
 841         case ALUA_STATUS_NONE:
 842                 return "None";
 843         case ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG:
 844                 return "Altered by Explicit STPG";
 845         case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
 846                 return "Altered by Implicit ALUA";
 847         default:
 848                 return "Unknown";
 849         }
 850 
 851         return NULL;
 852 }
 853 
 854 /*
 855  * Used by fabric modules to determine when we need to delay processing
 856  * for the Active/NonOptimized paths..
 857  */
 858 int core_alua_check_nonop_delay(
 859         struct se_cmd *cmd)
 860 {
 861         if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
 862                 return 0;
 863         if (in_interrupt())
 864                 return 0;
 865         /*
 866          * The ALUA Active/NonOptimized access state delay can be disabled
 867          * in via configfs with a value of zero
 868          */
 869         if (!cmd->alua_nonop_delay)
 870                 return 0;
 871         /*
 872          * struct se_cmd->alua_nonop_delay gets set by a target port group
 873          * defined interval in core_alua_state_nonoptimized()
 874          */
 875         msleep_interruptible(cmd->alua_nonop_delay);
 876         return 0;
 877 }
 878 EXPORT_SYMBOL(core_alua_check_nonop_delay);
 879 
 880 static int core_alua_write_tpg_metadata(
 881         const char *path,
 882         unsigned char *md_buf,
 883         u32 md_buf_len)
 884 {
 885         struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
 886         loff_t pos = 0;
 887         int ret;
 888 
 889         if (IS_ERR(file)) {
 890                 pr_err("filp_open(%s) for ALUA metadata failed\n", path);
 891                 return -ENODEV;
 892         }
 893         ret = kernel_write(file, md_buf, md_buf_len, &pos);
 894         if (ret < 0)
 895                 pr_err("Error writing ALUA metadata file: %s\n", path);
 896         fput(file);
 897         return (ret < 0) ? -EIO : 0;
 898 }
 899 
 900 static int core_alua_update_tpg_primary_metadata(
 901         struct t10_alua_tg_pt_gp *tg_pt_gp)
 902 {
 903         unsigned char *md_buf;
 904         struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
 905         char *path;
 906         int len, rc;
 907 
 908         lockdep_assert_held(&tg_pt_gp->tg_pt_gp_transition_mutex);
 909 
 910         md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
 911         if (!md_buf) {
 912                 pr_err("Unable to allocate buf for ALUA metadata\n");
 913                 return -ENOMEM;
 914         }
 915 
 916         len = snprintf(md_buf, ALUA_MD_BUF_LEN,
 917                         "tg_pt_gp_id=%hu\n"
 918                         "alua_access_state=0x%02x\n"
 919                         "alua_access_status=0x%02x\n",
 920                         tg_pt_gp->tg_pt_gp_id,
 921                         tg_pt_gp->tg_pt_gp_alua_access_state,
 922                         tg_pt_gp->tg_pt_gp_alua_access_status);
 923 
 924         rc = -ENOMEM;
 925         path = kasprintf(GFP_KERNEL, "%s/alua/tpgs_%s/%s", db_root,
 926                         &wwn->unit_serial[0],
 927                         config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 928         if (path) {
 929                 rc = core_alua_write_tpg_metadata(path, md_buf, len);
 930                 kfree(path);
 931         }
 932         kfree(md_buf);
 933         return rc;
 934 }
 935 
 936 static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
 937 {
 938         struct se_dev_entry *se_deve;
 939         struct se_lun *lun;
 940         struct se_lun_acl *lacl;
 941 
 942         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 943         list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
 944                                 lun_tg_pt_gp_link) {
 945                 /*
 946                  * After an implicit target port asymmetric access state
 947                  * change, a device server shall establish a unit attention
 948                  * condition for the initiator port associated with every I_T
 949                  * nexus with the additional sense code set to ASYMMETRIC
 950                  * ACCESS STATE CHANGED.
 951                  *
 952                  * After an explicit target port asymmetric access state
 953                  * change, a device server shall establish a unit attention
 954                  * condition with the additional sense code set to ASYMMETRIC
 955                  * ACCESS STATE CHANGED for the initiator port associated with
 956                  * every I_T nexus other than the I_T nexus on which the SET
 957                  * TARGET PORT GROUPS command
 958                  */
 959                 if (!percpu_ref_tryget_live(&lun->lun_ref))
 960                         continue;
 961                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 962 
 963                 spin_lock(&lun->lun_deve_lock);
 964                 list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
 965                         lacl = rcu_dereference_check(se_deve->se_lun_acl,
 966                                         lockdep_is_held(&lun->lun_deve_lock));
 967 
 968                         /*
 969                          * spc4r37 p.242:
 970                          * After an explicit target port asymmetric access
 971                          * state change, a device server shall establish a
 972                          * unit attention condition with the additional sense
 973                          * code set to ASYMMETRIC ACCESS STATE CHANGED for
 974                          * the initiator port associated with every I_T nexus
 975                          * other than the I_T nexus on which the SET TARGET
 976                          * PORT GROUPS command was received.
 977                          */
 978                         if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
 979                              ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
 980                            (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
 981                             (tg_pt_gp->tg_pt_gp_alua_lun == lun))
 982                                 continue;
 983 
 984                         /*
 985                          * se_deve->se_lun_acl pointer may be NULL for a
 986                          * entry created without explicit Node+MappedLUN ACLs
 987                          */
 988                         if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
 989                             (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
 990                                 continue;
 991 
 992                         core_scsi3_ua_allocate(se_deve, 0x2A,
 993                                 ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
 994                 }
 995                 spin_unlock(&lun->lun_deve_lock);
 996 
 997                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 998                 percpu_ref_put(&lun->lun_ref);
 999         }
1000         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1001 }
1002 
1003 static int core_alua_do_transition_tg_pt(
1004         struct t10_alua_tg_pt_gp *tg_pt_gp,
1005         int new_state,
1006         int explicit)
1007 {
1008         int prev_state;
1009 
1010         mutex_lock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1011         /* Nothing to be done here */
1012         if (tg_pt_gp->tg_pt_gp_alua_access_state == new_state) {
1013                 mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1014                 return 0;
1015         }
1016 
1017         if (explicit && new_state == ALUA_ACCESS_STATE_TRANSITION) {
1018                 mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1019                 return -EAGAIN;
1020         }
1021 
1022         /*
1023          * Save the old primary ALUA access state, and set the current state
1024          * to ALUA_ACCESS_STATE_TRANSITION.
1025          */
1026         prev_state = tg_pt_gp->tg_pt_gp_alua_access_state;
1027         tg_pt_gp->tg_pt_gp_alua_access_state = ALUA_ACCESS_STATE_TRANSITION;
1028         tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
1029                                 ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1030                                 ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1031 
1032         core_alua_queue_state_change_ua(tg_pt_gp);
1033 
1034         if (new_state == ALUA_ACCESS_STATE_TRANSITION) {
1035                 mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1036                 return 0;
1037         }
1038 
1039         /*
1040          * Check for the optional ALUA primary state transition delay
1041          */
1042         if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
1043                 msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1044 
1045         /*
1046          * Set the current primary ALUA access state to the requested new state
1047          */
1048         tg_pt_gp->tg_pt_gp_alua_access_state = new_state;
1049 
1050         /*
1051          * Update the ALUA metadata buf that has been allocated in
1052          * core_alua_do_port_transition(), this metadata will be written
1053          * to struct file.
1054          *
1055          * Note that there is the case where we do not want to update the
1056          * metadata when the saved metadata is being parsed in userspace
1057          * when setting the existing port access state and access status.
1058          *
1059          * Also note that the failure to write out the ALUA metadata to
1060          * struct file does NOT affect the actual ALUA transition.
1061          */
1062         if (tg_pt_gp->tg_pt_gp_write_metadata) {
1063                 core_alua_update_tpg_primary_metadata(tg_pt_gp);
1064         }
1065 
1066         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1067                 " from primary access state %s to %s\n", (explicit) ? "explicit" :
1068                 "implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1069                 tg_pt_gp->tg_pt_gp_id,
1070                 core_alua_dump_state(prev_state),
1071                 core_alua_dump_state(new_state));
1072 
1073         core_alua_queue_state_change_ua(tg_pt_gp);
1074 
1075         mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1076         return 0;
1077 }
1078 
1079 int core_alua_do_port_transition(
1080         struct t10_alua_tg_pt_gp *l_tg_pt_gp,
1081         struct se_device *l_dev,
1082         struct se_lun *l_lun,
1083         struct se_node_acl *l_nacl,
1084         int new_state,
1085         int explicit)
1086 {
1087         struct se_device *dev;
1088         struct t10_alua_lu_gp *lu_gp;
1089         struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
1090         struct t10_alua_tg_pt_gp *tg_pt_gp;
1091         int primary, valid_states, rc = 0;
1092 
1093         if (l_dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
1094                 return -ENODEV;
1095 
1096         valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
1097         if (core_alua_check_transition(new_state, valid_states, &primary,
1098                                        explicit) != 0)
1099                 return -EINVAL;
1100 
1101         local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
1102         spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
1103         lu_gp = local_lu_gp_mem->lu_gp;
1104         atomic_inc(&lu_gp->lu_gp_ref_cnt);
1105         spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
1106         /*
1107          * For storage objects that are members of the 'default_lu_gp',
1108          * we only do transition on the passed *l_tp_pt_gp, and not
1109          * on all of the matching target port groups IDs in default_lu_gp.
1110          */
1111         if (!lu_gp->lu_gp_id) {
1112                 /*
1113                  * core_alua_do_transition_tg_pt() will always return
1114                  * success.
1115                  */
1116                 l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1117                 l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1118                 rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
1119                                                    new_state, explicit);
1120                 atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1121                 return rc;
1122         }
1123         /*
1124          * For all other LU groups aside from 'default_lu_gp', walk all of
1125          * the associated storage objects looking for a matching target port
1126          * group ID from the local target port group.
1127          */
1128         spin_lock(&lu_gp->lu_gp_lock);
1129         list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
1130                                 lu_gp_mem_list) {
1131 
1132                 dev = lu_gp_mem->lu_gp_mem_dev;
1133                 atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1134                 spin_unlock(&lu_gp->lu_gp_lock);
1135 
1136                 spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1137                 list_for_each_entry(tg_pt_gp,
1138                                 &dev->t10_alua.tg_pt_gps_list,
1139                                 tg_pt_gp_list) {
1140 
1141                         if (!tg_pt_gp->tg_pt_gp_valid_id)
1142                                 continue;
1143                         /*
1144                          * If the target behavior port asymmetric access state
1145                          * is changed for any target port group accessible via
1146                          * a logical unit within a LU group, the target port
1147                          * behavior group asymmetric access states for the same
1148                          * target port group accessible via other logical units
1149                          * in that LU group will also change.
1150                          */
1151                         if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
1152                                 continue;
1153 
1154                         if (l_tg_pt_gp == tg_pt_gp) {
1155                                 tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1156                                 tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1157                         } else {
1158                                 tg_pt_gp->tg_pt_gp_alua_lun = NULL;
1159                                 tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
1160                         }
1161                         atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1162                         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1163                         /*
1164                          * core_alua_do_transition_tg_pt() will always return
1165                          * success.
1166                          */
1167                         rc = core_alua_do_transition_tg_pt(tg_pt_gp,
1168                                         new_state, explicit);
1169 
1170                         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1171                         atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1172                         if (rc)
1173                                 break;
1174                 }
1175                 spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1176 
1177                 spin_lock(&lu_gp->lu_gp_lock);
1178                 atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1179         }
1180         spin_unlock(&lu_gp->lu_gp_lock);
1181 
1182         if (!rc) {
1183                 pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1184                          " Group IDs: %hu %s transition to primary state: %s\n",
1185                          config_item_name(&lu_gp->lu_gp_group.cg_item),
1186                          l_tg_pt_gp->tg_pt_gp_id,
1187                          (explicit) ? "explicit" : "implicit",
1188                          core_alua_dump_state(new_state));
1189         }
1190 
1191         atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1192         return rc;
1193 }
1194 
1195 static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
1196 {
1197         struct se_portal_group *se_tpg = lun->lun_tpg;
1198         unsigned char *md_buf;
1199         char *path;
1200         int len, rc;
1201 
1202         mutex_lock(&lun->lun_tg_pt_md_mutex);
1203 
1204         md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
1205         if (!md_buf) {
1206                 pr_err("Unable to allocate buf for ALUA metadata\n");
1207                 rc = -ENOMEM;
1208                 goto out_unlock;
1209         }
1210 
1211         len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
1212                         "alua_tg_pt_status=0x%02x\n",
1213                         atomic_read(&lun->lun_tg_pt_secondary_offline),
1214                         lun->lun_tg_pt_secondary_stat);
1215 
1216         if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL) {
1217                 path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s+%hu/lun_%llu",
1218                                 db_root, se_tpg->se_tpg_tfo->fabric_name,
1219                                 se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1220                                 se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg),
1221                                 lun->unpacked_lun);
1222         } else {
1223                 path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s/lun_%llu",
1224                                 db_root, se_tpg->se_tpg_tfo->fabric_name,
1225                                 se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1226                                 lun->unpacked_lun);
1227         }
1228         if (!path) {
1229                 rc = -ENOMEM;
1230                 goto out_free;
1231         }
1232 
1233         rc = core_alua_write_tpg_metadata(path, md_buf, len);
1234         kfree(path);
1235 out_free:
1236         kfree(md_buf);
1237 out_unlock:
1238         mutex_unlock(&lun->lun_tg_pt_md_mutex);
1239         return rc;
1240 }
1241 
1242 static int core_alua_set_tg_pt_secondary_state(
1243         struct se_lun *lun,
1244         int explicit,
1245         int offline)
1246 {
1247         struct t10_alua_tg_pt_gp *tg_pt_gp;
1248         int trans_delay_msecs;
1249 
1250         spin_lock(&lun->lun_tg_pt_gp_lock);
1251         tg_pt_gp = lun->lun_tg_pt_gp;
1252         if (!tg_pt_gp) {
1253                 spin_unlock(&lun->lun_tg_pt_gp_lock);
1254                 pr_err("Unable to complete secondary state"
1255                                 " transition\n");
1256                 return -EINVAL;
1257         }
1258         trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1259         /*
1260          * Set the secondary ALUA target port access state to OFFLINE
1261          * or release the previously secondary state for struct se_lun
1262          */
1263         if (offline)
1264                 atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
1265         else
1266                 atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
1267 
1268         lun->lun_tg_pt_secondary_stat = (explicit) ?
1269                         ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1270                         ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1271 
1272         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1273                 " to secondary access state: %s\n", (explicit) ? "explicit" :
1274                 "implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1275                 tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1276 
1277         spin_unlock(&lun->lun_tg_pt_gp_lock);
1278         /*
1279          * Do the optional transition delay after we set the secondary
1280          * ALUA access state.
1281          */
1282         if (trans_delay_msecs != 0)
1283                 msleep_interruptible(trans_delay_msecs);
1284         /*
1285          * See if we need to update the ALUA fabric port metadata for
1286          * secondary state and status
1287          */
1288         if (lun->lun_tg_pt_secondary_write_md)
1289                 core_alua_update_tpg_secondary_metadata(lun);
1290 
1291         return 0;
1292 }
1293 
1294 struct t10_alua_lba_map *
1295 core_alua_allocate_lba_map(struct list_head *list,
1296                            u64 first_lba, u64 last_lba)
1297 {
1298         struct t10_alua_lba_map *lba_map;
1299 
1300         lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
1301         if (!lba_map) {
1302                 pr_err("Unable to allocate struct t10_alua_lba_map\n");
1303                 return ERR_PTR(-ENOMEM);
1304         }
1305         INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
1306         lba_map->lba_map_first_lba = first_lba;
1307         lba_map->lba_map_last_lba = last_lba;
1308 
1309         list_add_tail(&lba_map->lba_map_list, list);
1310         return lba_map;
1311 }
1312 
1313 int
1314 core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
1315                                int pg_id, int state)
1316 {
1317         struct t10_alua_lba_map_member *lba_map_mem;
1318 
1319         list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
1320                             lba_map_mem_list) {
1321                 if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
1322                         pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
1323                         return -EINVAL;
1324                 }
1325         }
1326 
1327         lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
1328         if (!lba_map_mem) {
1329                 pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
1330                 return -ENOMEM;
1331         }
1332         lba_map_mem->lba_map_mem_alua_state = state;
1333         lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
1334 
1335         list_add_tail(&lba_map_mem->lba_map_mem_list,
1336                       &lba_map->lba_map_mem_list);
1337         return 0;
1338 }
1339 
1340 void
1341 core_alua_free_lba_map(struct list_head *lba_list)
1342 {
1343         struct t10_alua_lba_map *lba_map, *lba_map_tmp;
1344         struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
1345 
1346         list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
1347                                  lba_map_list) {
1348                 list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
1349                                          &lba_map->lba_map_mem_list,
1350                                          lba_map_mem_list) {
1351                         list_del(&lba_map_mem->lba_map_mem_list);
1352                         kmem_cache_free(t10_alua_lba_map_mem_cache,
1353                                         lba_map_mem);
1354                 }
1355                 list_del(&lba_map->lba_map_list);
1356                 kmem_cache_free(t10_alua_lba_map_cache, lba_map);
1357         }
1358 }
1359 
1360 void
1361 core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
1362                       int segment_size, int segment_mult)
1363 {
1364         struct list_head old_lba_map_list;
1365         struct t10_alua_tg_pt_gp *tg_pt_gp;
1366         int activate = 0, supported;
1367 
1368         INIT_LIST_HEAD(&old_lba_map_list);
1369         spin_lock(&dev->t10_alua.lba_map_lock);
1370         dev->t10_alua.lba_map_segment_size = segment_size;
1371         dev->t10_alua.lba_map_segment_multiplier = segment_mult;
1372         list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
1373         if (lba_map_list) {
1374                 list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
1375                 activate = 1;
1376         }
1377         spin_unlock(&dev->t10_alua.lba_map_lock);
1378         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1379         list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1380                             tg_pt_gp_list) {
1381 
1382                 if (!tg_pt_gp->tg_pt_gp_valid_id)
1383                         continue;
1384                 supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
1385                 if (activate)
1386                         supported |= ALUA_LBD_SUP;
1387                 else
1388                         supported &= ~ALUA_LBD_SUP;
1389                 tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
1390         }
1391         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1392         core_alua_free_lba_map(&old_lba_map_list);
1393 }
1394 
1395 struct t10_alua_lu_gp *
1396 core_alua_allocate_lu_gp(const char *name, int def_group)
1397 {
1398         struct t10_alua_lu_gp *lu_gp;
1399 
1400         lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1401         if (!lu_gp) {
1402                 pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1403                 return ERR_PTR(-ENOMEM);
1404         }
1405         INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1406         INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1407         spin_lock_init(&lu_gp->lu_gp_lock);
1408         atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1409 
1410         if (def_group) {
1411                 lu_gp->lu_gp_id = alua_lu_gps_counter++;
1412                 lu_gp->lu_gp_valid_id = 1;
1413                 alua_lu_gps_count++;
1414         }
1415 
1416         return lu_gp;
1417 }
1418 
1419 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1420 {
1421         struct t10_alua_lu_gp *lu_gp_tmp;
1422         u16 lu_gp_id_tmp;
1423         /*
1424          * The lu_gp->lu_gp_id may only be set once..
1425          */
1426         if (lu_gp->lu_gp_valid_id) {
1427                 pr_warn("ALUA LU Group already has a valid ID,"
1428                         " ignoring request\n");
1429                 return -EINVAL;
1430         }
1431 
1432         spin_lock(&lu_gps_lock);
1433         if (alua_lu_gps_count == 0x0000ffff) {
1434                 pr_err("Maximum ALUA alua_lu_gps_count:"
1435                                 " 0x0000ffff reached\n");
1436                 spin_unlock(&lu_gps_lock);
1437                 kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1438                 return -ENOSPC;
1439         }
1440 again:
1441         lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1442                                 alua_lu_gps_counter++;
1443 
1444         list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1445                 if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1446                         if (!lu_gp_id)
1447                                 goto again;
1448 
1449                         pr_warn("ALUA Logical Unit Group ID: %hu"
1450                                 " already exists, ignoring request\n",
1451                                 lu_gp_id);
1452                         spin_unlock(&lu_gps_lock);
1453                         return -EINVAL;
1454                 }
1455         }
1456 
1457         lu_gp->lu_gp_id = lu_gp_id_tmp;
1458         lu_gp->lu_gp_valid_id = 1;
1459         list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1460         alua_lu_gps_count++;
1461         spin_unlock(&lu_gps_lock);
1462 
1463         return 0;
1464 }
1465 
1466 static struct t10_alua_lu_gp_member *
1467 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1468 {
1469         struct t10_alua_lu_gp_member *lu_gp_mem;
1470 
1471         lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1472         if (!lu_gp_mem) {
1473                 pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1474                 return ERR_PTR(-ENOMEM);
1475         }
1476         INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1477         spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1478         atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1479 
1480         lu_gp_mem->lu_gp_mem_dev = dev;
1481         dev->dev_alua_lu_gp_mem = lu_gp_mem;
1482 
1483         return lu_gp_mem;
1484 }
1485 
1486 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1487 {
1488         struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1489         /*
1490          * Once we have reached this point, config_item_put() has
1491          * already been called from target_core_alua_drop_lu_gp().
1492          *
1493          * Here, we remove the *lu_gp from the global list so that
1494          * no associations can be made while we are releasing
1495          * struct t10_alua_lu_gp.
1496          */
1497         spin_lock(&lu_gps_lock);
1498         list_del(&lu_gp->lu_gp_node);
1499         alua_lu_gps_count--;
1500         spin_unlock(&lu_gps_lock);
1501         /*
1502          * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1503          * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1504          * released with core_alua_put_lu_gp_from_name()
1505          */
1506         while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1507                 cpu_relax();
1508         /*
1509          * Release reference to struct t10_alua_lu_gp * from all associated
1510          * struct se_device.
1511          */
1512         spin_lock(&lu_gp->lu_gp_lock);
1513         list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1514                                 &lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1515                 if (lu_gp_mem->lu_gp_assoc) {
1516                         list_del(&lu_gp_mem->lu_gp_mem_list);
1517                         lu_gp->lu_gp_members--;
1518                         lu_gp_mem->lu_gp_assoc = 0;
1519                 }
1520                 spin_unlock(&lu_gp->lu_gp_lock);
1521                 /*
1522                  *
1523                  * lu_gp_mem is associated with a single
1524                  * struct se_device->dev_alua_lu_gp_mem, and is released when
1525                  * struct se_device is released via core_alua_free_lu_gp_mem().
1526                  *
1527                  * If the passed lu_gp does NOT match the default_lu_gp, assume
1528                  * we want to re-associate a given lu_gp_mem with default_lu_gp.
1529                  */
1530                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1531                 if (lu_gp != default_lu_gp)
1532                         __core_alua_attach_lu_gp_mem(lu_gp_mem,
1533                                         default_lu_gp);
1534                 else
1535                         lu_gp_mem->lu_gp = NULL;
1536                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1537 
1538                 spin_lock(&lu_gp->lu_gp_lock);
1539         }
1540         spin_unlock(&lu_gp->lu_gp_lock);
1541 
1542         kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1543 }
1544 
1545 void core_alua_free_lu_gp_mem(struct se_device *dev)
1546 {
1547         struct t10_alua_lu_gp *lu_gp;
1548         struct t10_alua_lu_gp_member *lu_gp_mem;
1549 
1550         lu_gp_mem = dev->dev_alua_lu_gp_mem;
1551         if (!lu_gp_mem)
1552                 return;
1553 
1554         while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1555                 cpu_relax();
1556 
1557         spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1558         lu_gp = lu_gp_mem->lu_gp;
1559         if (lu_gp) {
1560                 spin_lock(&lu_gp->lu_gp_lock);
1561                 if (lu_gp_mem->lu_gp_assoc) {
1562                         list_del(&lu_gp_mem->lu_gp_mem_list);
1563                         lu_gp->lu_gp_members--;
1564                         lu_gp_mem->lu_gp_assoc = 0;
1565                 }
1566                 spin_unlock(&lu_gp->lu_gp_lock);
1567                 lu_gp_mem->lu_gp = NULL;
1568         }
1569         spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1570 
1571         kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1572 }
1573 
1574 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1575 {
1576         struct t10_alua_lu_gp *lu_gp;
1577         struct config_item *ci;
1578 
1579         spin_lock(&lu_gps_lock);
1580         list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1581                 if (!lu_gp->lu_gp_valid_id)
1582                         continue;
1583                 ci = &lu_gp->lu_gp_group.cg_item;
1584                 if (!strcmp(config_item_name(ci), name)) {
1585                         atomic_inc(&lu_gp->lu_gp_ref_cnt);
1586                         spin_unlock(&lu_gps_lock);
1587                         return lu_gp;
1588                 }
1589         }
1590         spin_unlock(&lu_gps_lock);
1591 
1592         return NULL;
1593 }
1594 
1595 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1596 {
1597         spin_lock(&lu_gps_lock);
1598         atomic_dec(&lu_gp->lu_gp_ref_cnt);
1599         spin_unlock(&lu_gps_lock);
1600 }
1601 
1602 /*
1603  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1604  */
1605 void __core_alua_attach_lu_gp_mem(
1606         struct t10_alua_lu_gp_member *lu_gp_mem,
1607         struct t10_alua_lu_gp *lu_gp)
1608 {
1609         spin_lock(&lu_gp->lu_gp_lock);
1610         lu_gp_mem->lu_gp = lu_gp;
1611         lu_gp_mem->lu_gp_assoc = 1;
1612         list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1613         lu_gp->lu_gp_members++;
1614         spin_unlock(&lu_gp->lu_gp_lock);
1615 }
1616 
1617 /*
1618  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1619  */
1620 void __core_alua_drop_lu_gp_mem(
1621         struct t10_alua_lu_gp_member *lu_gp_mem,
1622         struct t10_alua_lu_gp *lu_gp)
1623 {
1624         spin_lock(&lu_gp->lu_gp_lock);
1625         list_del(&lu_gp_mem->lu_gp_mem_list);
1626         lu_gp_mem->lu_gp = NULL;
1627         lu_gp_mem->lu_gp_assoc = 0;
1628         lu_gp->lu_gp_members--;
1629         spin_unlock(&lu_gp->lu_gp_lock);
1630 }
1631 
1632 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1633                 const char *name, int def_group)
1634 {
1635         struct t10_alua_tg_pt_gp *tg_pt_gp;
1636 
1637         tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1638         if (!tg_pt_gp) {
1639                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1640                 return NULL;
1641         }
1642         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1643         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
1644         mutex_init(&tg_pt_gp->tg_pt_gp_transition_mutex);
1645         spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1646         atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1647         tg_pt_gp->tg_pt_gp_dev = dev;
1648         tg_pt_gp->tg_pt_gp_alua_access_state =
1649                         ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED;
1650         /*
1651          * Enable both explicit and implicit ALUA support by default
1652          */
1653         tg_pt_gp->tg_pt_gp_alua_access_type =
1654                         TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
1655         /*
1656          * Set the default Active/NonOptimized Delay in milliseconds
1657          */
1658         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1659         tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1660         tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
1661 
1662         /*
1663          * Enable all supported states
1664          */
1665         tg_pt_gp->tg_pt_gp_alua_supported_states =
1666             ALUA_T_SUP | ALUA_O_SUP |
1667             ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
1668 
1669         if (def_group) {
1670                 spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1671                 tg_pt_gp->tg_pt_gp_id =
1672                                 dev->t10_alua.alua_tg_pt_gps_counter++;
1673                 tg_pt_gp->tg_pt_gp_valid_id = 1;
1674                 dev->t10_alua.alua_tg_pt_gps_count++;
1675                 list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1676                               &dev->t10_alua.tg_pt_gps_list);
1677                 spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1678         }
1679 
1680         return tg_pt_gp;
1681 }
1682 
1683 int core_alua_set_tg_pt_gp_id(
1684         struct t10_alua_tg_pt_gp *tg_pt_gp,
1685         u16 tg_pt_gp_id)
1686 {
1687         struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1688         struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1689         u16 tg_pt_gp_id_tmp;
1690 
1691         /*
1692          * The tg_pt_gp->tg_pt_gp_id may only be set once..
1693          */
1694         if (tg_pt_gp->tg_pt_gp_valid_id) {
1695                 pr_warn("ALUA TG PT Group already has a valid ID,"
1696                         " ignoring request\n");
1697                 return -EINVAL;
1698         }
1699 
1700         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1701         if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1702                 pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1703                         " 0x0000ffff reached\n");
1704                 spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1705                 kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1706                 return -ENOSPC;
1707         }
1708 again:
1709         tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1710                         dev->t10_alua.alua_tg_pt_gps_counter++;
1711 
1712         list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1713                         tg_pt_gp_list) {
1714                 if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1715                         if (!tg_pt_gp_id)
1716                                 goto again;
1717 
1718                         pr_err("ALUA Target Port Group ID: %hu already"
1719                                 " exists, ignoring request\n", tg_pt_gp_id);
1720                         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1721                         return -EINVAL;
1722                 }
1723         }
1724 
1725         tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1726         tg_pt_gp->tg_pt_gp_valid_id = 1;
1727         list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1728                         &dev->t10_alua.tg_pt_gps_list);
1729         dev->t10_alua.alua_tg_pt_gps_count++;
1730         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1731 
1732         return 0;
1733 }
1734 
1735 void core_alua_free_tg_pt_gp(
1736         struct t10_alua_tg_pt_gp *tg_pt_gp)
1737 {
1738         struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1739         struct se_lun *lun, *next;
1740 
1741         /*
1742          * Once we have reached this point, config_item_put() has already
1743          * been called from target_core_alua_drop_tg_pt_gp().
1744          *
1745          * Here we remove *tg_pt_gp from the global list so that
1746          * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
1747          * can be made while we are releasing struct t10_alua_tg_pt_gp.
1748          */
1749         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1750         if (tg_pt_gp->tg_pt_gp_valid_id) {
1751                 list_del(&tg_pt_gp->tg_pt_gp_list);
1752                 dev->t10_alua.alua_tg_pt_gps_count--;
1753         }
1754         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1755 
1756         /*
1757          * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1758          * core_alua_get_tg_pt_gp_by_name() in
1759          * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1760          * to be released with core_alua_put_tg_pt_gp_from_name().
1761          */
1762         while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1763                 cpu_relax();
1764 
1765         /*
1766          * Release reference to struct t10_alua_tg_pt_gp from all associated
1767          * struct se_port.
1768          */
1769         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1770         list_for_each_entry_safe(lun, next,
1771                         &tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
1772                 list_del_init(&lun->lun_tg_pt_gp_link);
1773                 tg_pt_gp->tg_pt_gp_members--;
1774 
1775                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1776                 /*
1777                  * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1778                  * assume we want to re-associate a given tg_pt_gp_mem with
1779                  * default_tg_pt_gp.
1780                  */
1781                 spin_lock(&lun->lun_tg_pt_gp_lock);
1782                 if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1783                         __target_attach_tg_pt_gp(lun,
1784                                         dev->t10_alua.default_tg_pt_gp);
1785                 } else
1786                         lun->lun_tg_pt_gp = NULL;
1787                 spin_unlock(&lun->lun_tg_pt_gp_lock);
1788 
1789                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1790         }
1791         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1792 
1793         kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1794 }
1795 
1796 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1797                 struct se_device *dev, const char *name)
1798 {
1799         struct t10_alua_tg_pt_gp *tg_pt_gp;
1800         struct config_item *ci;
1801 
1802         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1803         list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1804                         tg_pt_gp_list) {
1805                 if (!tg_pt_gp->tg_pt_gp_valid_id)
1806                         continue;
1807                 ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1808                 if (!strcmp(config_item_name(ci), name)) {
1809                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1810                         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1811                         return tg_pt_gp;
1812                 }
1813         }
1814         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1815 
1816         return NULL;
1817 }
1818 
1819 static void core_alua_put_tg_pt_gp_from_name(
1820         struct t10_alua_tg_pt_gp *tg_pt_gp)
1821 {
1822         struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1823 
1824         spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1825         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1826         spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1827 }
1828 
1829 static void __target_attach_tg_pt_gp(struct se_lun *lun,
1830                 struct t10_alua_tg_pt_gp *tg_pt_gp)
1831 {
1832         struct se_dev_entry *se_deve;
1833 
1834         assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1835 
1836         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1837         lun->lun_tg_pt_gp = tg_pt_gp;
1838         list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
1839         tg_pt_gp->tg_pt_gp_members++;
1840         spin_lock(&lun->lun_deve_lock);
1841         list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
1842                 core_scsi3_ua_allocate(se_deve, 0x3f,
1843                                        ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
1844         spin_unlock(&lun->lun_deve_lock);
1845         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1846 }
1847 
1848 void target_attach_tg_pt_gp(struct se_lun *lun,
1849                 struct t10_alua_tg_pt_gp *tg_pt_gp)
1850 {
1851         spin_lock(&lun->lun_tg_pt_gp_lock);
1852         __target_attach_tg_pt_gp(lun, tg_pt_gp);
1853         spin_unlock(&lun->lun_tg_pt_gp_lock);
1854 }
1855 
1856 static void __target_detach_tg_pt_gp(struct se_lun *lun,
1857                 struct t10_alua_tg_pt_gp *tg_pt_gp)
1858 {
1859         assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1860 
1861         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1862         list_del_init(&lun->lun_tg_pt_gp_link);
1863         tg_pt_gp->tg_pt_gp_members--;
1864         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1865 
1866         lun->lun_tg_pt_gp = NULL;
1867 }
1868 
1869 void target_detach_tg_pt_gp(struct se_lun *lun)
1870 {
1871         struct t10_alua_tg_pt_gp *tg_pt_gp;
1872 
1873         spin_lock(&lun->lun_tg_pt_gp_lock);
1874         tg_pt_gp = lun->lun_tg_pt_gp;
1875         if (tg_pt_gp)
1876                 __target_detach_tg_pt_gp(lun, tg_pt_gp);
1877         spin_unlock(&lun->lun_tg_pt_gp_lock);
1878 }
1879 
1880 ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
1881 {
1882         struct config_item *tg_pt_ci;
1883         struct t10_alua_tg_pt_gp *tg_pt_gp;
1884         ssize_t len = 0;
1885 
1886         spin_lock(&lun->lun_tg_pt_gp_lock);
1887         tg_pt_gp = lun->lun_tg_pt_gp;
1888         if (tg_pt_gp) {
1889                 tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1890                 len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1891                         " %hu\nTG Port Primary Access State: %s\nTG Port "
1892                         "Primary Access Status: %s\nTG Port Secondary Access"
1893                         " State: %s\nTG Port Secondary Access Status: %s\n",
1894                         config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1895                         core_alua_dump_state(
1896                                 tg_pt_gp->tg_pt_gp_alua_access_state),
1897                         core_alua_dump_status(
1898                                 tg_pt_gp->tg_pt_gp_alua_access_status),
1899                         atomic_read(&lun->lun_tg_pt_secondary_offline) ?
1900                         "Offline" : "None",
1901                         core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
1902         }
1903         spin_unlock(&lun->lun_tg_pt_gp_lock);
1904 
1905         return len;
1906 }
1907 
1908 ssize_t core_alua_store_tg_pt_gp_info(
1909         struct se_lun *lun,
1910         const char *page,
1911         size_t count)
1912 {
1913         struct se_portal_group *tpg = lun->lun_tpg;
1914         /*
1915          * rcu_dereference_raw protected by se_lun->lun_group symlink
1916          * reference to se_device->dev_group.
1917          */
1918         struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
1919         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1920         unsigned char buf[TG_PT_GROUP_NAME_BUF];
1921         int move = 0;
1922 
1923         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
1924             (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
1925                 return -ENODEV;
1926 
1927         if (count > TG_PT_GROUP_NAME_BUF) {
1928                 pr_err("ALUA Target Port Group alias too large!\n");
1929                 return -EINVAL;
1930         }
1931         memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1932         memcpy(buf, page, count);
1933         /*
1934          * Any ALUA target port group alias besides "NULL" means we will be
1935          * making a new group association.
1936          */
1937         if (strcmp(strstrip(buf), "NULL")) {
1938                 /*
1939                  * core_alua_get_tg_pt_gp_by_name() will increment reference to
1940                  * struct t10_alua_tg_pt_gp.  This reference is released with
1941                  * core_alua_put_tg_pt_gp_from_name() below.
1942                  */
1943                 tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1944                                         strstrip(buf));
1945                 if (!tg_pt_gp_new)
1946                         return -ENODEV;
1947         }
1948 
1949         spin_lock(&lun->lun_tg_pt_gp_lock);
1950         tg_pt_gp = lun->lun_tg_pt_gp;
1951         if (tg_pt_gp) {
1952                 /*
1953                  * Clearing an existing tg_pt_gp association, and replacing
1954                  * with the default_tg_pt_gp.
1955                  */
1956                 if (!tg_pt_gp_new) {
1957                         pr_debug("Target_Core_ConfigFS: Moving"
1958                                 " %s/tpgt_%hu/%s from ALUA Target Port Group:"
1959                                 " alua/%s, ID: %hu back to"
1960                                 " default_tg_pt_gp\n",
1961                                 tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1962                                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1963                                 config_item_name(&lun->lun_group.cg_item),
1964                                 config_item_name(
1965                                         &tg_pt_gp->tg_pt_gp_group.cg_item),
1966                                 tg_pt_gp->tg_pt_gp_id);
1967 
1968                         __target_detach_tg_pt_gp(lun, tg_pt_gp);
1969                         __target_attach_tg_pt_gp(lun,
1970                                         dev->t10_alua.default_tg_pt_gp);
1971                         spin_unlock(&lun->lun_tg_pt_gp_lock);
1972 
1973                         return count;
1974                 }
1975                 __target_detach_tg_pt_gp(lun, tg_pt_gp);
1976                 move = 1;
1977         }
1978 
1979         __target_attach_tg_pt_gp(lun, tg_pt_gp_new);
1980         spin_unlock(&lun->lun_tg_pt_gp_lock);
1981         pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1982                 " Target Port Group: alua/%s, ID: %hu\n", (move) ?
1983                 "Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1984                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1985                 config_item_name(&lun->lun_group.cg_item),
1986                 config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1987                 tg_pt_gp_new->tg_pt_gp_id);
1988 
1989         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1990         return count;
1991 }
1992 
1993 ssize_t core_alua_show_access_type(
1994         struct t10_alua_tg_pt_gp *tg_pt_gp,
1995         char *page)
1996 {
1997         if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
1998             (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
1999                 return sprintf(page, "Implicit and Explicit\n");
2000         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
2001                 return sprintf(page, "Implicit\n");
2002         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
2003                 return sprintf(page, "Explicit\n");
2004         else
2005                 return sprintf(page, "None\n");
2006 }
2007 
2008 ssize_t core_alua_store_access_type(
2009         struct t10_alua_tg_pt_gp *tg_pt_gp,
2010         const char *page,
2011         size_t count)
2012 {
2013         unsigned long tmp;
2014         int ret;
2015 
2016         ret = kstrtoul(page, 0, &tmp);
2017         if (ret < 0) {
2018                 pr_err("Unable to extract alua_access_type\n");
2019                 return ret;
2020         }
2021         if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
2022                 pr_err("Illegal value for alua_access_type:"
2023                                 " %lu\n", tmp);
2024                 return -EINVAL;
2025         }
2026         if (tmp == 3)
2027                 tg_pt_gp->tg_pt_gp_alua_access_type =
2028                         TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
2029         else if (tmp == 2)
2030                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
2031         else if (tmp == 1)
2032                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
2033         else
2034                 tg_pt_gp->tg_pt_gp_alua_access_type = 0;
2035 
2036         return count;
2037 }
2038 
2039 ssize_t core_alua_show_nonop_delay_msecs(
2040         struct t10_alua_tg_pt_gp *tg_pt_gp,
2041         char *page)
2042 {
2043         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
2044 }
2045 
2046 ssize_t core_alua_store_nonop_delay_msecs(
2047         struct t10_alua_tg_pt_gp *tg_pt_gp,
2048         const char *page,
2049         size_t count)
2050 {
2051         unsigned long tmp;
2052         int ret;
2053 
2054         ret = kstrtoul(page, 0, &tmp);
2055         if (ret < 0) {
2056                 pr_err("Unable to extract nonop_delay_msecs\n");
2057                 return ret;
2058         }
2059         if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
2060                 pr_err("Passed nonop_delay_msecs: %lu, exceeds"
2061                         " ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
2062                         ALUA_MAX_NONOP_DELAY_MSECS);
2063                 return -EINVAL;
2064         }
2065         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
2066 
2067         return count;
2068 }
2069 
2070 ssize_t core_alua_show_trans_delay_msecs(
2071         struct t10_alua_tg_pt_gp *tg_pt_gp,
2072         char *page)
2073 {
2074         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
2075 }
2076 
2077 ssize_t core_alua_store_trans_delay_msecs(
2078         struct t10_alua_tg_pt_gp *tg_pt_gp,
2079         const char *page,
2080         size_t count)
2081 {
2082         unsigned long tmp;
2083         int ret;
2084 
2085         ret = kstrtoul(page, 0, &tmp);
2086         if (ret < 0) {
2087                 pr_err("Unable to extract trans_delay_msecs\n");
2088                 return ret;
2089         }
2090         if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
2091                 pr_err("Passed trans_delay_msecs: %lu, exceeds"
2092                         " ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
2093                         ALUA_MAX_TRANS_DELAY_MSECS);
2094                 return -EINVAL;
2095         }
2096         tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
2097 
2098         return count;
2099 }
2100 
2101 ssize_t core_alua_show_implicit_trans_secs(
2102         struct t10_alua_tg_pt_gp *tg_pt_gp,
2103         char *page)
2104 {
2105         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
2106 }
2107 
2108 ssize_t core_alua_store_implicit_trans_secs(
2109         struct t10_alua_tg_pt_gp *tg_pt_gp,
2110         const char *page,
2111         size_t count)
2112 {
2113         unsigned long tmp;
2114         int ret;
2115 
2116         ret = kstrtoul(page, 0, &tmp);
2117         if (ret < 0) {
2118                 pr_err("Unable to extract implicit_trans_secs\n");
2119                 return ret;
2120         }
2121         if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
2122                 pr_err("Passed implicit_trans_secs: %lu, exceeds"
2123                         " ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
2124                         ALUA_MAX_IMPLICIT_TRANS_SECS);
2125                 return  -EINVAL;
2126         }
2127         tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
2128 
2129         return count;
2130 }
2131 
2132 ssize_t core_alua_show_preferred_bit(
2133         struct t10_alua_tg_pt_gp *tg_pt_gp,
2134         char *page)
2135 {
2136         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
2137 }
2138 
2139 ssize_t core_alua_store_preferred_bit(
2140         struct t10_alua_tg_pt_gp *tg_pt_gp,
2141         const char *page,
2142         size_t count)
2143 {
2144         unsigned long tmp;
2145         int ret;
2146 
2147         ret = kstrtoul(page, 0, &tmp);
2148         if (ret < 0) {
2149                 pr_err("Unable to extract preferred ALUA value\n");
2150                 return ret;
2151         }
2152         if ((tmp != 0) && (tmp != 1)) {
2153                 pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
2154                 return -EINVAL;
2155         }
2156         tg_pt_gp->tg_pt_gp_pref = (int)tmp;
2157 
2158         return count;
2159 }
2160 
2161 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
2162 {
2163         return sprintf(page, "%d\n",
2164                 atomic_read(&lun->lun_tg_pt_secondary_offline));
2165 }
2166 
2167 ssize_t core_alua_store_offline_bit(
2168         struct se_lun *lun,
2169         const char *page,
2170         size_t count)
2171 {
2172         /*
2173          * rcu_dereference_raw protected by se_lun->lun_group symlink
2174          * reference to se_device->dev_group.
2175          */
2176         struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
2177         unsigned long tmp;
2178         int ret;
2179 
2180         if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
2181             (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
2182                 return -ENODEV;
2183 
2184         ret = kstrtoul(page, 0, &tmp);
2185         if (ret < 0) {
2186                 pr_err("Unable to extract alua_tg_pt_offline value\n");
2187                 return ret;
2188         }
2189         if ((tmp != 0) && (tmp != 1)) {
2190                 pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
2191                                 tmp);
2192                 return -EINVAL;
2193         }
2194 
2195         ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
2196         if (ret < 0)
2197                 return -EINVAL;
2198 
2199         return count;
2200 }
2201 
2202 ssize_t core_alua_show_secondary_status(
2203         struct se_lun *lun,
2204         char *page)
2205 {
2206         return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
2207 }
2208 
2209 ssize_t core_alua_store_secondary_status(
2210         struct se_lun *lun,
2211         const char *page,
2212         size_t count)
2213 {
2214         unsigned long tmp;
2215         int ret;
2216 
2217         ret = kstrtoul(page, 0, &tmp);
2218         if (ret < 0) {
2219                 pr_err("Unable to extract alua_tg_pt_status\n");
2220                 return ret;
2221         }
2222         if ((tmp != ALUA_STATUS_NONE) &&
2223             (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
2224             (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
2225                 pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2226                                 tmp);
2227                 return -EINVAL;
2228         }
2229         lun->lun_tg_pt_secondary_stat = (int)tmp;
2230 
2231         return count;
2232 }
2233 
2234 ssize_t core_alua_show_secondary_write_metadata(
2235         struct se_lun *lun,
2236         char *page)
2237 {
2238         return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
2239 }
2240 
2241 ssize_t core_alua_store_secondary_write_metadata(
2242         struct se_lun *lun,
2243         const char *page,
2244         size_t count)
2245 {
2246         unsigned long tmp;
2247         int ret;
2248 
2249         ret = kstrtoul(page, 0, &tmp);
2250         if (ret < 0) {
2251                 pr_err("Unable to extract alua_tg_pt_write_md\n");
2252                 return ret;
2253         }
2254         if ((tmp != 0) && (tmp != 1)) {
2255                 pr_err("Illegal value for alua_tg_pt_write_md:"
2256                                 " %lu\n", tmp);
2257                 return -EINVAL;
2258         }
2259         lun->lun_tg_pt_secondary_write_md = (int)tmp;
2260 
2261         return count;
2262 }
2263 
2264 int core_setup_alua(struct se_device *dev)
2265 {
2266         if (!(dev->transport->transport_flags &
2267              TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
2268             !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2269                 struct t10_alua_lu_gp_member *lu_gp_mem;
2270 
2271                 /*
2272                  * Associate this struct se_device with the default ALUA
2273                  * LUN Group.
2274                  */
2275                 lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2276                 if (IS_ERR(lu_gp_mem))
2277                         return PTR_ERR(lu_gp_mem);
2278 
2279                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2280                 __core_alua_attach_lu_gp_mem(lu_gp_mem,
2281                                 default_lu_gp);
2282                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2283 
2284                 pr_debug("%s: Adding to default ALUA LU Group:"
2285                         " core/alua/lu_gps/default_lu_gp\n",
2286                         dev->transport->name);
2287         }
2288 
2289         return 0;
2290 }
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/target/target_core_alua.c

DEFINITIONS
