drivers/target/target_core_alua.c

   1 /*******************************************************************************
   2  * Filename:  target_core_alua.c
   3  *
   4  * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
   5  *
   6  * Copyright (c) 2009-2010 Rising Tide Systems
   7  * Copyright (c) 2009-2010 Linux-iSCSI.org
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  *
  25  ******************************************************************************/
  26
  27 #include <linux/slab.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/configfs.h>
  30 #include <linux/export.h>
  31 #include <scsi/scsi.h>
  32 #include <scsi/scsi_cmnd.h>
  33
  34 #include <target/target_core_base.h>
  35 #include <target/target_core_device.h>
  36 #include <target/target_core_transport.h>
  37 #include <target/target_core_fabric_ops.h>
  38 #include <target/target_core_configfs.h>
  39
  40 #include "target_core_alua.h"
  41 #include "target_core_hba.h"
  42 #include "target_core_ua.h"
  43
  44 static int core_alua_check_transition(int state, int *primary);
  45 static int core_alua_set_tg_pt_secondary_state(
  46                 struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
  47                 struct se_port *port, int explict, int offline);
  48
  49 static u16 alua_lu_gps_counter;
  50 static u32 alua_lu_gps_count;
  51
  52 static DEFINE_SPINLOCK(lu_gps_lock);
  53 static LIST_HEAD(lu_gps_list);
  54
  55 struct t10_alua_lu_gp *default_lu_gp;
  56
  57 /*
  58  * REPORT_TARGET_PORT_GROUPS
  59  *
  60  * See spc4r17 section 6.27
  61  */
  62 int target_emulate_report_target_port_groups(struct se_task *task)
  63 {
  64         struct se_cmd *cmd = task->task_se_cmd;
  65         struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
  66         struct se_port *port;
  67         struct t10_alua_tg_pt_gp *tg_pt_gp;
  68         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
  69         unsigned char *buf;
  70         u32 rd_len = 0, off = 4; /* Skip over RESERVED area to first
  71                                     Target port group descriptor */
  72         /*
  73          * Need at least 4 bytes of response data or else we can't
  74          * even fit the return data length.
  75          */
  76         if (cmd->data_length < 4) {
  77                 pr_warn("REPORT TARGET PORT GROUPS allocation length %u"
  78                         " too small\n", cmd->data_length);
  79                 return -EINVAL;
  80         }
  81
  82         buf = transport_kmap_first_data_page(cmd);
  83
  84         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
  85         list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
  86                         tg_pt_gp_list) {
  87                 /*
  88                  * Check if the Target port group and Target port descriptor list
  89                  * based on tg_pt_gp_members count will fit into the response payload.
  90                  * Otherwise, bump rd_len to let the initiator know we have exceeded
  91                  * the allocation length and the response is truncated.
  92                  */
  93                 if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
  94                      cmd->data_length) {
  95                         rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
  96                         continue;
  97                 }
  98                 /*
  99                  * PREF: Preferred target port bit, determine if this
 100                  * bit should be set for port group.
 101                  */
 102                 if (tg_pt_gp->tg_pt_gp_pref)
 103                         buf[off] = 0x80;
 104                 /*
 105                  * Set the ASYMMETRIC ACCESS State
 106                  */
 107                 buf[off++] |= (atomic_read(
 108                         &tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
 109                 /*
 110                  * Set supported ASYMMETRIC ACCESS State bits
 111                  */
 112                 buf[off] = 0x80; /* T_SUP */
 113                 buf[off] |= 0x40; /* O_SUP */
 114                 buf[off] |= 0x8; /* U_SUP */
 115                 buf[off] |= 0x4; /* S_SUP */
 116                 buf[off] |= 0x2; /* AN_SUP */
 117                 buf[off++] |= 0x1; /* AO_SUP */
 118                 /*
 119                  * TARGET PORT GROUP
 120                  */
 121                 buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
 122                 buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
 123
 124                 off++; /* Skip over Reserved */
 125                 /*
 126                  * STATUS CODE
 127                  */
 128                 buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
 129                 /*
 130                  * Vendor Specific field
 131                  */
 132                 buf[off++] = 0x00;
 133                 /*
 134                  * TARGET PORT COUNT
 135                  */
 136                 buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
 137                 rd_len += 8;
 138
 139                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 140                 list_for_each_entry(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
 141                                 tg_pt_gp_mem_list) {
 142                         port = tg_pt_gp_mem->tg_pt;
 143                         /*
 144                          * Start Target Port descriptor format
 145                          *
 146                          * See spc4r17 section 6.2.7 Table 247
 147                          */
 148                         off += 2; /* Skip over Obsolete */
 149                         /*
 150                          * Set RELATIVE TARGET PORT IDENTIFIER
 151                          */
 152                         buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
 153                         buf[off++] = (port->sep_rtpi & 0xff);
 154                         rd_len += 4;
 155                 }
 156                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 157         }
 158         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 159         /*
 160          * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 161          */
 162         buf[0] = ((rd_len >> 24) & 0xff);
 163         buf[1] = ((rd_len >> 16) & 0xff);
 164         buf[2] = ((rd_len >> 8) & 0xff);
 165         buf[3] = (rd_len & 0xff);
 166
 167         transport_kunmap_first_data_page(cmd);
 168
 169         task->task_scsi_status = GOOD;
 170         transport_complete_task(task, 1);
 171         return 0;
 172 }
 173
 174 /*
 175  * SET_TARGET_PORT_GROUPS for explict ALUA operation.
 176  *
 177  * See spc4r17 section 6.35
 178  */
 179 int target_emulate_set_target_port_groups(struct se_task *task)
 180 {
 181         struct se_cmd *cmd = task->task_se_cmd;
 182         struct se_device *dev = cmd->se_dev;
 183         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
 184         struct se_port *port, *l_port = cmd->se_lun->lun_sep;
 185         struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
 186         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
 187         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
 188         unsigned char *buf;
 189         unsigned char *ptr;
 190         u32 len = 4; /* Skip over RESERVED area in header */
 191         int alua_access_state, primary = 0, rc;
 192         u16 tg_pt_id, rtpi;
 193
 194         if (!l_port) {
 195                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 196                 return -EINVAL;
 197         }
 198         buf = transport_kmap_first_data_page(cmd);
 199
 200         /*
 201          * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
 202          * for the local tg_pt_gp.
 203          */
 204         l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
 205         if (!l_tg_pt_gp_mem) {
 206                 pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
 207                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 208                 rc = -EINVAL;
 209                 goto out;
 210         }
 211         spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 212         l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
 213         if (!l_tg_pt_gp) {
 214                 spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 215                 pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
 216                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 217                 rc = -EINVAL;
 218                 goto out;
 219         }
 220         rc = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
 221         spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 222
 223         if (!rc) {
 224                 pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
 225                                 " while TPGS_EXPLICT_ALUA is disabled\n");
 226                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 227                 rc = -EINVAL;
 228                 goto out;
 229         }
 230
 231         ptr = &buf[4]; /* Skip over RESERVED area in header */
 232
 233         while (len < cmd->data_length) {
 234                 alua_access_state = (ptr[0] & 0x0f);
 235                 /*
 236                  * Check the received ALUA access state, and determine if
 237                  * the state is a primary or secondary target port asymmetric
 238                  * access state.
 239                  */
 240                 rc = core_alua_check_transition(alua_access_state, &primary);
 241                 if (rc != 0) {
 242                         /*
 243                          * If the SET TARGET PORT GROUPS attempts to establish
 244                          * an invalid combination of target port asymmetric
 245                          * access states or attempts to establish an
 246                          * unsupported target port asymmetric access state,
 247                          * then the command shall be terminated with CHECK
 248                          * CONDITION status, with the sense key set to ILLEGAL
 249                          * REQUEST, and the additional sense code set to INVALID
 250                          * FIELD IN PARAMETER LIST.
 251                          */
 252                         cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 253                         rc = -EINVAL;
 254                         goto out;
 255                 }
 256                 rc = -1;
 257                 /*
 258                  * If the ASYMMETRIC ACCESS STATE field (see table 267)
 259                  * specifies a primary target port asymmetric access state,
 260                  * then the TARGET PORT GROUP OR TARGET PORT field specifies
 261                  * a primary target port group for which the primary target
 262                  * port asymmetric access state shall be changed. If the
 263                  * ASYMMETRIC ACCESS STATE field specifies a secondary target
 264                  * port asymmetric access state, then the TARGET PORT GROUP OR
 265                  * TARGET PORT field specifies the relative target port
 266                  * identifier (see 3.1.120) of the target port for which the
 267                  * secondary target port asymmetric access state shall be
 268                  * changed.
 269                  */
 270                 if (primary) {
 271                         tg_pt_id = ((ptr[2] << 8) & 0xff);
 272                         tg_pt_id |= (ptr[3] & 0xff);
 273                         /*
 274                          * Locate the matching target port group ID from
 275                          * the global tg_pt_gp list
 276                          */
 277                         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 278                         list_for_each_entry(tg_pt_gp,
 279                                         &su_dev->t10_alua.tg_pt_gps_list,
 280                                         tg_pt_gp_list) {
 281                                 if (!tg_pt_gp->tg_pt_gp_valid_id)
 282                                         continue;
 283
 284                                 if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
 285                                         continue;
 286
 287                                 atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 288                                 smp_mb__after_atomic_inc();
 289                                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 290
 291                                 rc = core_alua_do_port_transition(tg_pt_gp,
 292                                                 dev, l_port, nacl,
 293                                                 alua_access_state, 1);
 294
 295                                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 296                                 atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
 297                                 smp_mb__after_atomic_dec();
 298                                 break;
 299                         }
 300                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 301                         /*
 302                          * If not matching target port group ID can be located
 303                          * throw an exception with ASCQ: INVALID_PARAMETER_LIST
 304                          */
 305                         if (rc != 0) {
 306                                 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 307                                 rc = -EINVAL;
 308                                 goto out;
 309                         }
 310                 } else {
 311                         /*
 312                          * Extact the RELATIVE TARGET PORT IDENTIFIER to identify
 313                          * the Target Port in question for the the incoming
 314                          * SET_TARGET_PORT_GROUPS op.
 315                          */
 316                         rtpi = ((ptr[2] << 8) & 0xff);
 317                         rtpi |= (ptr[3] & 0xff);
 318                         /*
 319                          * Locate the matching relative target port identifer
 320                          * for the struct se_device storage object.
 321                          */
 322                         spin_lock(&dev->se_port_lock);
 323                         list_for_each_entry(port, &dev->dev_sep_list,
 324                                                         sep_list) {
 325                                 if (port->sep_rtpi != rtpi)
 326                                         continue;
 327
 328                                 tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 329                                 spin_unlock(&dev->se_port_lock);
 330
 331                                 rc = core_alua_set_tg_pt_secondary_state(
 332                                                 tg_pt_gp_mem, port, 1, 1);
 333
 334                                 spin_lock(&dev->se_port_lock);
 335                                 break;
 336                         }
 337                         spin_unlock(&dev->se_port_lock);
 338                         /*
 339                          * If not matching relative target port identifier can
 340                          * be located, throw an exception with ASCQ:
 341                          * INVALID_PARAMETER_LIST
 342                          */
 343                         if (rc != 0) {
 344                                 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 345                                 rc = -EINVAL;
 346                                 goto out;
 347                         }
 348                 }
 349
 350                 ptr += 4;
 351                 len += 4;
 352         }
 353
 354 out:
 355         transport_kunmap_first_data_page(cmd);
 356         task->task_scsi_status = GOOD;
 357         transport_complete_task(task, 1);
 358         return 0;
 359 }
 360
 361 static inline int core_alua_state_nonoptimized(
 362         struct se_cmd *cmd,
 363         unsigned char *cdb,
 364         int nonop_delay_msecs,
 365         u8 *alua_ascq)
 366 {
 367         /*
 368          * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
 369          * later to determine if processing of this cmd needs to be
 370          * temporarily delayed for the Active/NonOptimized primary access state.
 371          */
 372         cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
 373         cmd->alua_nonop_delay = nonop_delay_msecs;
 374         return 0;
 375 }
 376
 377 static inline int core_alua_state_standby(
 378         struct se_cmd *cmd,
 379         unsigned char *cdb,
 380         u8 *alua_ascq)
 381 {
 382         /*
 383          * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
 384          * spc4r17 section 5.9.2.4.4
 385          */
 386         switch (cdb[0]) {
 387         case INQUIRY:
 388         case LOG_SELECT:
 389         case LOG_SENSE:
 390         case MODE_SELECT:
 391         case MODE_SENSE:
 392         case REPORT_LUNS:
 393         case RECEIVE_DIAGNOSTIC:
 394         case SEND_DIAGNOSTIC:
 395         case MAINTENANCE_IN:
 396                 switch (cdb[1]) {
 397                 case MI_REPORT_TARGET_PGS:
 398                         return 0;
 399                 default:
 400                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 401                         return 1;
 402                 }
 403         case MAINTENANCE_OUT:
 404                 switch (cdb[1]) {
 405                 case MO_SET_TARGET_PGS:
 406                         return 0;
 407                 default:
 408                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 409                         return 1;
 410                 }
 411         case REQUEST_SENSE:
 412         case PERSISTENT_RESERVE_IN:
 413         case PERSISTENT_RESERVE_OUT:
 414         case READ_BUFFER:
 415         case WRITE_BUFFER:
 416                 return 0;
 417         default:
 418                 *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 419                 return 1;
 420         }
 421
 422         return 0;
 423 }
 424
 425 static inline int core_alua_state_unavailable(
 426         struct se_cmd *cmd,
 427         unsigned char *cdb,
 428         u8 *alua_ascq)
 429 {
 430         /*
 431          * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
 432          * spc4r17 section 5.9.2.4.5
 433          */
 434         switch (cdb[0]) {
 435         case INQUIRY:
 436         case REPORT_LUNS:
 437         case MAINTENANCE_IN:
 438                 switch (cdb[1]) {
 439                 case MI_REPORT_TARGET_PGS:
 440                         return 0;
 441                 default:
 442                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 443                         return 1;
 444                 }
 445         case MAINTENANCE_OUT:
 446                 switch (cdb[1]) {
 447                 case MO_SET_TARGET_PGS:
 448                         return 0;
 449                 default:
 450                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 451                         return 1;
 452                 }
 453         case REQUEST_SENSE:
 454         case READ_BUFFER:
 455         case WRITE_BUFFER:
 456                 return 0;
 457         default:
 458                 *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 459                 return 1;
 460         }
 461
 462         return 0;
 463 }
 464
 465 static inline int core_alua_state_transition(
 466         struct se_cmd *cmd,
 467         unsigned char *cdb,
 468         u8 *alua_ascq)
 469 {
 470         /*
 471          * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
 472          * spc4r17 section 5.9.2.5
 473          */
 474         switch (cdb[0]) {
 475         case INQUIRY:
 476         case REPORT_LUNS:
 477         case MAINTENANCE_IN:
 478                 switch (cdb[1]) {
 479                 case MI_REPORT_TARGET_PGS:
 480                         return 0;
 481                 default:
 482                         *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 483                         return 1;
 484                 }
 485         case REQUEST_SENSE:
 486         case READ_BUFFER:
 487         case WRITE_BUFFER:
 488                 return 0;
 489         default:
 490                 *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 491                 return 1;
 492         }
 493
 494         return 0;
 495 }
 496
 497 /*
 498  * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
 499  * in transport_cmd_sequencer().  This function is assigned to
 500  * struct t10_alua *->state_check() in core_setup_alua()
 501  */
 502 static int core_alua_state_check_nop(
 503         struct se_cmd *cmd,
 504         unsigned char *cdb,
 505         u8 *alua_ascq)
 506 {
 507         return 0;
 508 }
 509
 510 /*
 511  * Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
 512  * This function is assigned to struct t10_alua *->state_check() in
 513  * core_setup_alua()
 514  *
 515  * Also, this function can return three different return codes to
 516  * signal transport_generic_cmd_sequencer()
 517  *
 518  * return 1: Is used to signal LUN not accecsable, and check condition/not ready
 519  * return 0: Used to signal success
 520  * reutrn -1: Used to signal failure, and invalid cdb field
 521  */
 522 static int core_alua_state_check(
 523         struct se_cmd *cmd,
 524         unsigned char *cdb,
 525         u8 *alua_ascq)
 526 {
 527         struct se_lun *lun = cmd->se_lun;
 528         struct se_port *port = lun->lun_sep;
 529         struct t10_alua_tg_pt_gp *tg_pt_gp;
 530         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
 531         int out_alua_state, nonop_delay_msecs;
 532
 533         if (!port)
 534                 return 0;
 535         /*
 536          * First, check for a struct se_port specific secondary ALUA target port
 537          * access state: OFFLINE
 538          */
 539         if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
 540                 *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 541                 pr_debug("ALUA: Got secondary offline status for local"
 542                                 " target port\n");
 543                 *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 544                 return 1;
 545         }
 546          /*
 547          * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
 548          * ALUA target port group, to obtain current ALUA access state.
 549          * Otherwise look for the underlying struct se_device association with
 550          * a ALUA logical unit group.
 551          */
 552         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 553         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 554         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
 555         out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 556         nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
 557         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 558         /*
 559          * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a separate conditional
 560          * statement so the compiler knows explicitly to check this case first.
 561          * For the Optimized ALUA access state case, we want to process the
 562          * incoming fabric cmd ASAP..
 563          */
 564         if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
 565                 return 0;
 566
 567         switch (out_alua_state) {
 568         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 569                 return core_alua_state_nonoptimized(cmd, cdb,
 570                                         nonop_delay_msecs, alua_ascq);
 571         case ALUA_ACCESS_STATE_STANDBY:
 572                 return core_alua_state_standby(cmd, cdb, alua_ascq);
 573         case ALUA_ACCESS_STATE_UNAVAILABLE:
 574                 return core_alua_state_unavailable(cmd, cdb, alua_ascq);
 575         case ALUA_ACCESS_STATE_TRANSITION:
 576                 return core_alua_state_transition(cmd, cdb, alua_ascq);
 577         /*
 578          * OFFLINE is a secondary ALUA target port group access state, that is
 579          * handled above with struct se_port->sep_tg_pt_secondary_offline=1
 580          */
 581         case ALUA_ACCESS_STATE_OFFLINE:
 582         default:
 583                 pr_err("Unknown ALUA access state: 0x%02x\n",
 584                                 out_alua_state);
 585                 return -EINVAL;
 586         }
 587
 588         return 0;
 589 }
 590
 591 /*
 592  * Check implict and explict ALUA state change request.
 593  */
 594 static int core_alua_check_transition(int state, int *primary)
 595 {
 596         switch (state) {
 597         case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 598         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 599         case ALUA_ACCESS_STATE_STANDBY:
 600         case ALUA_ACCESS_STATE_UNAVAILABLE:
 601                 /*
 602                  * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
 603                  * defined as primary target port asymmetric access states.
 604                  */
 605                 *primary = 1;
 606                 break;
 607         case ALUA_ACCESS_STATE_OFFLINE:
 608                 /*
 609                  * OFFLINE state is defined as a secondary target port
 610                  * asymmetric access state.
 611                  */
 612                 *primary = 0;
 613                 break;
 614         default:
 615                 pr_err("Unknown ALUA access state: 0x%02x\n", state);
 616                 return -EINVAL;
 617         }
 618
 619         return 0;
 620 }
 621
 622 static char *core_alua_dump_state(int state)
 623 {
 624         switch (state) {
 625         case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 626                 return "Active/Optimized";
 627         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 628                 return "Active/NonOptimized";
 629         case ALUA_ACCESS_STATE_STANDBY:
 630                 return "Standby";
 631         case ALUA_ACCESS_STATE_UNAVAILABLE:
 632                 return "Unavailable";
 633         case ALUA_ACCESS_STATE_OFFLINE:
 634                 return "Offline";
 635         default:
 636                 return "Unknown";
 637         }
 638
 639         return NULL;
 640 }
 641
 642 char *core_alua_dump_status(int status)
 643 {
 644         switch (status) {
 645         case ALUA_STATUS_NONE:
 646                 return "None";
 647         case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
 648                 return "Altered by Explict STPG";
 649         case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
 650                 return "Altered by Implict ALUA";
 651         default:
 652                 return "Unknown";
 653         }
 654
 655         return NULL;
 656 }
 657
 658 /*
 659  * Used by fabric modules to determine when we need to delay processing
 660  * for the Active/NonOptimized paths..
 661  */
 662 int core_alua_check_nonop_delay(
 663         struct se_cmd *cmd)
 664 {
 665         if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
 666                 return 0;
 667         if (in_interrupt())
 668                 return 0;
 669         /*
 670          * The ALUA Active/NonOptimized access state delay can be disabled
 671          * in via configfs with a value of zero
 672          */
 673         if (!cmd->alua_nonop_delay)
 674                 return 0;
 675         /*
 676          * struct se_cmd->alua_nonop_delay gets set by a target port group
 677          * defined interval in core_alua_state_nonoptimized()
 678          */
 679         msleep_interruptible(cmd->alua_nonop_delay);
 680         return 0;
 681 }
 682 EXPORT_SYMBOL(core_alua_check_nonop_delay);
 683
 684 /*
 685  * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
 686  *
 687  */
 688 static int core_alua_write_tpg_metadata(
 689         const char *path,
 690         unsigned char *md_buf,
 691         u32 md_buf_len)
 692 {
 693         mm_segment_t old_fs;
 694         struct file *file;
 695         struct iovec iov[1];
 696         int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
 697
 698         memset(iov, 0, sizeof(struct iovec));
 699
 700         file = filp_open(path, flags, 0600);
 701         if (IS_ERR(file) || !file || !file->f_dentry) {
 702                 pr_err("filp_open(%s) for ALUA metadata failed\n",
 703                         path);
 704                 return -ENODEV;
 705         }
 706
 707         iov[0].iov_base = &md_buf[0];
 708         iov[0].iov_len = md_buf_len;
 709
 710         old_fs = get_fs();
 711         set_fs(get_ds());
 712         ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
 713         set_fs(old_fs);
 714
 715         if (ret < 0) {
 716                 pr_err("Error writing ALUA metadata file: %s\n", path);
 717                 filp_close(file, NULL);
 718                 return -EIO;
 719         }
 720         filp_close(file, NULL);
 721
 722         return 0;
 723 }
 724
 725 /*
 726  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
 727  */
 728 static int core_alua_update_tpg_primary_metadata(
 729         struct t10_alua_tg_pt_gp *tg_pt_gp,
 730         int primary_state,
 731         unsigned char *md_buf)
 732 {
 733         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
 734         struct t10_wwn *wwn = &su_dev->t10_wwn;
 735         char path[ALUA_METADATA_PATH_LEN];
 736         int len;
 737
 738         memset(path, 0, ALUA_METADATA_PATH_LEN);
 739
 740         len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
 741                         "tg_pt_gp_id=%hu\n"
 742                         "alua_access_state=0x%02x\n"
 743                         "alua_access_status=0x%02x\n",
 744                         tg_pt_gp->tg_pt_gp_id, primary_state,
 745                         tg_pt_gp->tg_pt_gp_alua_access_status);
 746
 747         snprintf(path, ALUA_METADATA_PATH_LEN,
 748                 "/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
 749                 config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 750
 751         return core_alua_write_tpg_metadata(path, md_buf, len);
 752 }
 753
 754 static int core_alua_do_transition_tg_pt(
 755         struct t10_alua_tg_pt_gp *tg_pt_gp,
 756         struct se_port *l_port,
 757         struct se_node_acl *nacl,
 758         unsigned char *md_buf,
 759         int new_state,
 760         int explict)
 761 {
 762         struct se_dev_entry *se_deve;
 763         struct se_lun_acl *lacl;
 764         struct se_port *port;
 765         struct t10_alua_tg_pt_gp_member *mem;
 766         int old_state = 0;
 767         /*
 768          * Save the old primary ALUA access state, and set the current state
 769          * to ALUA_ACCESS_STATE_TRANSITION.
 770          */
 771         old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 772         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
 773                         ALUA_ACCESS_STATE_TRANSITION);
 774         tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
 775                                 ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
 776                                 ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
 777         /*
 778          * Check for the optional ALUA primary state transition delay
 779          */
 780         if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
 781                 msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
 782
 783         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 784         list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
 785                                 tg_pt_gp_mem_list) {
 786                 port = mem->tg_pt;
 787                 /*
 788                  * After an implicit target port asymmetric access state
 789                  * change, a device server shall establish a unit attention
 790                  * condition for the initiator port associated with every I_T
 791                  * nexus with the additional sense code set to ASYMMETRIC
 792                  * ACCESS STATE CHAGED.
 793                  *
 794                  * After an explicit target port asymmetric access state
 795                  * change, a device server shall establish a unit attention
 796                  * condition with the additional sense code set to ASYMMETRIC
 797                  * ACCESS STATE CHANGED for the initiator port associated with
 798                  * every I_T nexus other than the I_T nexus on which the SET
 799                  * TARGET PORT GROUPS command
 800                  */
 801                 atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
 802                 smp_mb__after_atomic_inc();
 803                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 804
 805                 spin_lock_bh(&port->sep_alua_lock);
 806                 list_for_each_entry(se_deve, &port->sep_alua_list,
 807                                         alua_port_list) {
 808                         lacl = se_deve->se_lun_acl;
 809                         /*
 810                          * se_deve->se_lun_acl pointer may be NULL for a
 811                          * entry created without explict Node+MappedLUN ACLs
 812                          */
 813                         if (!lacl)
 814                                 continue;
 815
 816                         if (explict &&
 817                            (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
 818                            (l_port != NULL) && (l_port == port))
 819                                 continue;
 820
 821                         core_scsi3_ua_allocate(lacl->se_lun_nacl,
 822                                 se_deve->mapped_lun, 0x2A,
 823                                 ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
 824                 }
 825                 spin_unlock_bh(&port->sep_alua_lock);
 826
 827                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 828                 atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
 829                 smp_mb__after_atomic_dec();
 830         }
 831         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 832         /*
 833          * Update the ALUA metadata buf that has been allocated in
 834          * core_alua_do_port_transition(), this metadata will be written
 835          * to struct file.
 836          *
 837          * Note that there is the case where we do not want to update the
 838          * metadata when the saved metadata is being parsed in userspace
 839          * when setting the existing port access state and access status.
 840          *
 841          * Also note that the failure to write out the ALUA metadata to
 842          * struct file does NOT affect the actual ALUA transition.
 843          */
 844         if (tg_pt_gp->tg_pt_gp_write_metadata) {
 845                 mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
 846                 core_alua_update_tpg_primary_metadata(tg_pt_gp,
 847                                         new_state, md_buf);
 848                 mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
 849         }
 850         /*
 851          * Set the current primary ALUA access state to the requested new state
 852          */
 853         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
 854
 855         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
 856                 " from primary access state %s to %s\n", (explict) ? "explict" :
 857                 "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
 858                 tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
 859                 core_alua_dump_state(new_state));
 860
 861         return 0;
 862 }
 863
 864 int core_alua_do_port_transition(
 865         struct t10_alua_tg_pt_gp *l_tg_pt_gp,
 866         struct se_device *l_dev,
 867         struct se_port *l_port,
 868         struct se_node_acl *l_nacl,
 869         int new_state,
 870         int explict)
 871 {
 872         struct se_device *dev;
 873         struct se_port *port;
 874         struct se_subsystem_dev *su_dev;
 875         struct se_node_acl *nacl;
 876         struct t10_alua_lu_gp *lu_gp;
 877         struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
 878         struct t10_alua_tg_pt_gp *tg_pt_gp;
 879         unsigned char *md_buf;
 880         int primary;
 881
 882         if (core_alua_check_transition(new_state, &primary) != 0)
 883                 return -EINVAL;
 884
 885         md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
 886         if (!md_buf) {
 887                 pr_err("Unable to allocate buf for ALUA metadata\n");
 888                 return -ENOMEM;
 889         }
 890
 891         local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
 892         spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
 893         lu_gp = local_lu_gp_mem->lu_gp;
 894         atomic_inc(&lu_gp->lu_gp_ref_cnt);
 895         smp_mb__after_atomic_inc();
 896         spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
 897         /*
 898          * For storage objects that are members of the 'default_lu_gp',
 899          * we only do transition on the passed *l_tp_pt_gp, and not
 900          * on all of the matching target port groups IDs in default_lu_gp.
 901          */
 902         if (!lu_gp->lu_gp_id) {
 903                 /*
 904                  * core_alua_do_transition_tg_pt() will always return
 905                  * success.
 906                  */
 907                 core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
 908                                         md_buf, new_state, explict);
 909                 atomic_dec(&lu_gp->lu_gp_ref_cnt);
 910                 smp_mb__after_atomic_dec();
 911                 kfree(md_buf);
 912                 return 0;
 913         }
 914         /*
 915          * For all other LU groups aside from 'default_lu_gp', walk all of
 916          * the associated storage objects looking for a matching target port
 917          * group ID from the local target port group.
 918          */
 919         spin_lock(&lu_gp->lu_gp_lock);
 920         list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
 921                                 lu_gp_mem_list) {
 922
 923                 dev = lu_gp_mem->lu_gp_mem_dev;
 924                 su_dev = dev->se_sub_dev;
 925                 atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
 926                 smp_mb__after_atomic_inc();
 927                 spin_unlock(&lu_gp->lu_gp_lock);
 928
 929                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 930                 list_for_each_entry(tg_pt_gp,
 931                                 &su_dev->t10_alua.tg_pt_gps_list,
 932                                 tg_pt_gp_list) {
 933
 934                         if (!tg_pt_gp->tg_pt_gp_valid_id)
 935                                 continue;
 936                         /*
 937                          * If the target behavior port asymmetric access state
 938                          * is changed for any target port group accessiable via
 939                          * a logical unit within a LU group, the target port
 940                          * behavior group asymmetric access states for the same
 941                          * target port group accessible via other logical units
 942                          * in that LU group will also change.
 943                          */
 944                         if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
 945                                 continue;
 946
 947                         if (l_tg_pt_gp == tg_pt_gp) {
 948                                 port = l_port;
 949                                 nacl = l_nacl;
 950                         } else {
 951                                 port = NULL;
 952                                 nacl = NULL;
 953                         }
 954                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 955                         smp_mb__after_atomic_inc();
 956                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 957                         /*
 958                          * core_alua_do_transition_tg_pt() will always return
 959                          * success.
 960                          */
 961                         core_alua_do_transition_tg_pt(tg_pt_gp, port,
 962                                         nacl, md_buf, new_state, explict);
 963
 964                         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 965                         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
 966                         smp_mb__after_atomic_dec();
 967                 }
 968                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 969
 970                 spin_lock(&lu_gp->lu_gp_lock);
 971                 atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
 972                 smp_mb__after_atomic_dec();
 973         }
 974         spin_unlock(&lu_gp->lu_gp_lock);
 975
 976         pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
 977                 " Group IDs: %hu %s transition to primary state: %s\n",
 978                 config_item_name(&lu_gp->lu_gp_group.cg_item),
 979                 l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
 980                 core_alua_dump_state(new_state));
 981
 982         atomic_dec(&lu_gp->lu_gp_ref_cnt);
 983         smp_mb__after_atomic_dec();
 984         kfree(md_buf);
 985         return 0;
 986 }
 987
 988 /*
 989  * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
 990  */
 991 static int core_alua_update_tpg_secondary_metadata(
 992         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
 993         struct se_port *port,
 994         unsigned char *md_buf,
 995         u32 md_buf_len)
 996 {
 997         struct se_portal_group *se_tpg = port->sep_tpg;
 998         char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
 999         int len;
1000
1001         memset(path, 0, ALUA_METADATA_PATH_LEN);
1002         memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1003
1004         len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1005                         se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1006
1007         if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1008                 snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1009                                 se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1010
1011         len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1012                         "alua_tg_pt_status=0x%02x\n",
1013                         atomic_read(&port->sep_tg_pt_secondary_offline),
1014                         port->sep_tg_pt_secondary_stat);
1015
1016         snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1017                         se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1018                         port->sep_lun->unpacked_lun);
1019
1020         return core_alua_write_tpg_metadata(path, md_buf, len);
1021 }
1022
1023 static int core_alua_set_tg_pt_secondary_state(
1024         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1025         struct se_port *port,
1026         int explict,
1027         int offline)
1028 {
1029         struct t10_alua_tg_pt_gp *tg_pt_gp;
1030         unsigned char *md_buf;
1031         u32 md_buf_len;
1032         int trans_delay_msecs;
1033
1034         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1035         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1036         if (!tg_pt_gp) {
1037                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1038                 pr_err("Unable to complete secondary state"
1039                                 " transition\n");
1040                 return -EINVAL;
1041         }
1042         trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1043         /*
1044          * Set the secondary ALUA target port access state to OFFLINE
1045          * or release the previously secondary state for struct se_port
1046          */
1047         if (offline)
1048                 atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1049         else
1050                 atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1051
1052         md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1053         port->sep_tg_pt_secondary_stat = (explict) ?
1054                         ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
1055                         ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
1056
1057         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1058                 " to secondary access state: %s\n", (explict) ? "explict" :
1059                 "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1060                 tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1061
1062         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1063         /*
1064          * Do the optional transition delay after we set the secondary
1065          * ALUA access state.
1066          */
1067         if (trans_delay_msecs != 0)
1068                 msleep_interruptible(trans_delay_msecs);
1069         /*
1070          * See if we need to update the ALUA fabric port metadata for
1071          * secondary state and status
1072          */
1073         if (port->sep_tg_pt_secondary_write_md) {
1074                 md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1075                 if (!md_buf) {
1076                         pr_err("Unable to allocate md_buf for"
1077                                 " secondary ALUA access metadata\n");
1078                         return -ENOMEM;
1079                 }
1080                 mutex_lock(&port->sep_tg_pt_md_mutex);
1081                 core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1082                                 md_buf, md_buf_len);
1083                 mutex_unlock(&port->sep_tg_pt_md_mutex);
1084
1085                 kfree(md_buf);
1086         }
1087
1088         return 0;
1089 }
1090
1091 struct t10_alua_lu_gp *
1092 core_alua_allocate_lu_gp(const char *name, int def_group)
1093 {
1094         struct t10_alua_lu_gp *lu_gp;
1095
1096         lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1097         if (!lu_gp) {
1098                 pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1099                 return ERR_PTR(-ENOMEM);
1100         }
1101         INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1102         INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1103         spin_lock_init(&lu_gp->lu_gp_lock);
1104         atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1105
1106         if (def_group) {
1107                 lu_gp->lu_gp_id = alua_lu_gps_counter++;
1108                 lu_gp->lu_gp_valid_id = 1;
1109                 alua_lu_gps_count++;
1110         }
1111
1112         return lu_gp;
1113 }
1114
1115 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1116 {
1117         struct t10_alua_lu_gp *lu_gp_tmp;
1118         u16 lu_gp_id_tmp;
1119         /*
1120          * The lu_gp->lu_gp_id may only be set once..
1121          */
1122         if (lu_gp->lu_gp_valid_id) {
1123                 pr_warn("ALUA LU Group already has a valid ID,"
1124                         " ignoring request\n");
1125                 return -EINVAL;
1126         }
1127
1128         spin_lock(&lu_gps_lock);
1129         if (alua_lu_gps_count == 0x0000ffff) {
1130                 pr_err("Maximum ALUA alua_lu_gps_count:"
1131                                 " 0x0000ffff reached\n");
1132                 spin_unlock(&lu_gps_lock);
1133                 kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1134                 return -ENOSPC;
1135         }
1136 again:
1137         lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1138                                 alua_lu_gps_counter++;
1139
1140         list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1141                 if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1142                         if (!lu_gp_id)
1143                                 goto again;
1144
1145                         pr_warn("ALUA Logical Unit Group ID: %hu"
1146                                 " already exists, ignoring request\n",
1147                                 lu_gp_id);
1148                         spin_unlock(&lu_gps_lock);
1149                         return -EINVAL;
1150                 }
1151         }
1152
1153         lu_gp->lu_gp_id = lu_gp_id_tmp;
1154         lu_gp->lu_gp_valid_id = 1;
1155         list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1156         alua_lu_gps_count++;
1157         spin_unlock(&lu_gps_lock);
1158
1159         return 0;
1160 }
1161
1162 static struct t10_alua_lu_gp_member *
1163 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1164 {
1165         struct t10_alua_lu_gp_member *lu_gp_mem;
1166
1167         lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1168         if (!lu_gp_mem) {
1169                 pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1170                 return ERR_PTR(-ENOMEM);
1171         }
1172         INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1173         spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1174         atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1175
1176         lu_gp_mem->lu_gp_mem_dev = dev;
1177         dev->dev_alua_lu_gp_mem = lu_gp_mem;
1178
1179         return lu_gp_mem;
1180 }
1181
1182 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1183 {
1184         struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1185         /*
1186          * Once we have reached this point, config_item_put() has
1187          * already been called from target_core_alua_drop_lu_gp().
1188          *
1189          * Here, we remove the *lu_gp from the global list so that
1190          * no associations can be made while we are releasing
1191          * struct t10_alua_lu_gp.
1192          */
1193         spin_lock(&lu_gps_lock);
1194         atomic_set(&lu_gp->lu_gp_shutdown, 1);
1195         list_del(&lu_gp->lu_gp_node);
1196         alua_lu_gps_count--;
1197         spin_unlock(&lu_gps_lock);
1198         /*
1199          * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1200          * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1201          * released with core_alua_put_lu_gp_from_name()
1202          */
1203         while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1204                 cpu_relax();
1205         /*
1206          * Release reference to struct t10_alua_lu_gp * from all associated
1207          * struct se_device.
1208          */
1209         spin_lock(&lu_gp->lu_gp_lock);
1210         list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1211                                 &lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1212                 if (lu_gp_mem->lu_gp_assoc) {
1213                         list_del(&lu_gp_mem->lu_gp_mem_list);
1214                         lu_gp->lu_gp_members--;
1215                         lu_gp_mem->lu_gp_assoc = 0;
1216                 }
1217                 spin_unlock(&lu_gp->lu_gp_lock);
1218                 /*
1219                  *
1220                  * lu_gp_mem is associated with a single
1221                  * struct se_device->dev_alua_lu_gp_mem, and is released when
1222                  * struct se_device is released via core_alua_free_lu_gp_mem().
1223                  *
1224                  * If the passed lu_gp does NOT match the default_lu_gp, assume
1225                  * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1226                  */
1227                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1228                 if (lu_gp != default_lu_gp)
1229                         __core_alua_attach_lu_gp_mem(lu_gp_mem,
1230                                         default_lu_gp);
1231                 else
1232                         lu_gp_mem->lu_gp = NULL;
1233                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1234
1235                 spin_lock(&lu_gp->lu_gp_lock);
1236         }
1237         spin_unlock(&lu_gp->lu_gp_lock);
1238
1239         kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1240 }
1241
1242 void core_alua_free_lu_gp_mem(struct se_device *dev)
1243 {
1244         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1245         struct t10_alua *alua = &su_dev->t10_alua;
1246         struct t10_alua_lu_gp *lu_gp;
1247         struct t10_alua_lu_gp_member *lu_gp_mem;
1248
1249         if (alua->alua_type != SPC3_ALUA_EMULATED)
1250                 return;
1251
1252         lu_gp_mem = dev->dev_alua_lu_gp_mem;
1253         if (!lu_gp_mem)
1254                 return;
1255
1256         while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1257                 cpu_relax();
1258
1259         spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1260         lu_gp = lu_gp_mem->lu_gp;
1261         if (lu_gp) {
1262                 spin_lock(&lu_gp->lu_gp_lock);
1263                 if (lu_gp_mem->lu_gp_assoc) {
1264                         list_del(&lu_gp_mem->lu_gp_mem_list);
1265                         lu_gp->lu_gp_members--;
1266                         lu_gp_mem->lu_gp_assoc = 0;
1267                 }
1268                 spin_unlock(&lu_gp->lu_gp_lock);
1269                 lu_gp_mem->lu_gp = NULL;
1270         }
1271         spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1272
1273         kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1274 }
1275
1276 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1277 {
1278         struct t10_alua_lu_gp *lu_gp;
1279         struct config_item *ci;
1280
1281         spin_lock(&lu_gps_lock);
1282         list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1283                 if (!lu_gp->lu_gp_valid_id)
1284                         continue;
1285                 ci = &lu_gp->lu_gp_group.cg_item;
1286                 if (!strcmp(config_item_name(ci), name)) {
1287                         atomic_inc(&lu_gp->lu_gp_ref_cnt);
1288                         spin_unlock(&lu_gps_lock);
1289                         return lu_gp;
1290                 }
1291         }
1292         spin_unlock(&lu_gps_lock);
1293
1294         return NULL;
1295 }
1296
1297 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1298 {
1299         spin_lock(&lu_gps_lock);
1300         atomic_dec(&lu_gp->lu_gp_ref_cnt);
1301         spin_unlock(&lu_gps_lock);
1302 }
1303
1304 /*
1305  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1306  */
1307 void __core_alua_attach_lu_gp_mem(
1308         struct t10_alua_lu_gp_member *lu_gp_mem,
1309         struct t10_alua_lu_gp *lu_gp)
1310 {
1311         spin_lock(&lu_gp->lu_gp_lock);
1312         lu_gp_mem->lu_gp = lu_gp;
1313         lu_gp_mem->lu_gp_assoc = 1;
1314         list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1315         lu_gp->lu_gp_members++;
1316         spin_unlock(&lu_gp->lu_gp_lock);
1317 }
1318
1319 /*
1320  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1321  */
1322 void __core_alua_drop_lu_gp_mem(
1323         struct t10_alua_lu_gp_member *lu_gp_mem,
1324         struct t10_alua_lu_gp *lu_gp)
1325 {
1326         spin_lock(&lu_gp->lu_gp_lock);
1327         list_del(&lu_gp_mem->lu_gp_mem_list);
1328         lu_gp_mem->lu_gp = NULL;
1329         lu_gp_mem->lu_gp_assoc = 0;
1330         lu_gp->lu_gp_members--;
1331         spin_unlock(&lu_gp->lu_gp_lock);
1332 }
1333
1334 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
1335         struct se_subsystem_dev *su_dev,
1336         const char *name,
1337         int def_group)
1338 {
1339         struct t10_alua_tg_pt_gp *tg_pt_gp;
1340
1341         tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1342         if (!tg_pt_gp) {
1343                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1344                 return NULL;
1345         }
1346         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1347         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1348         mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1349         spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1350         atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1351         tg_pt_gp->tg_pt_gp_su_dev = su_dev;
1352         tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1353         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1354                 ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1355         /*
1356          * Enable both explict and implict ALUA support by default
1357          */
1358         tg_pt_gp->tg_pt_gp_alua_access_type =
1359                         TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1360         /*
1361          * Set the default Active/NonOptimized Delay in milliseconds
1362          */
1363         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1364         tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1365
1366         if (def_group) {
1367                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1368                 tg_pt_gp->tg_pt_gp_id =
1369                                 su_dev->t10_alua.alua_tg_pt_gps_counter++;
1370                 tg_pt_gp->tg_pt_gp_valid_id = 1;
1371                 su_dev->t10_alua.alua_tg_pt_gps_count++;
1372                 list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1373                               &su_dev->t10_alua.tg_pt_gps_list);
1374                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1375         }
1376
1377         return tg_pt_gp;
1378 }
1379
1380 int core_alua_set_tg_pt_gp_id(
1381         struct t10_alua_tg_pt_gp *tg_pt_gp,
1382         u16 tg_pt_gp_id)
1383 {
1384         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1385         struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1386         u16 tg_pt_gp_id_tmp;
1387         /*
1388          * The tg_pt_gp->tg_pt_gp_id may only be set once..
1389          */
1390         if (tg_pt_gp->tg_pt_gp_valid_id) {
1391                 pr_warn("ALUA TG PT Group already has a valid ID,"
1392                         " ignoring request\n");
1393                 return -EINVAL;
1394         }
1395
1396         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1397         if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1398                 pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1399                         " 0x0000ffff reached\n");
1400                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1401                 kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1402                 return -ENOSPC;
1403         }
1404 again:
1405         tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1406                         su_dev->t10_alua.alua_tg_pt_gps_counter++;
1407
1408         list_for_each_entry(tg_pt_gp_tmp, &su_dev->t10_alua.tg_pt_gps_list,
1409                         tg_pt_gp_list) {
1410                 if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1411                         if (!tg_pt_gp_id)
1412                                 goto again;
1413
1414                         pr_err("ALUA Target Port Group ID: %hu already"
1415                                 " exists, ignoring request\n", tg_pt_gp_id);
1416                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1417                         return -EINVAL;
1418                 }
1419         }
1420
1421         tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1422         tg_pt_gp->tg_pt_gp_valid_id = 1;
1423         list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1424                         &su_dev->t10_alua.tg_pt_gps_list);
1425         su_dev->t10_alua.alua_tg_pt_gps_count++;
1426         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1427
1428         return 0;
1429 }
1430
1431 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1432         struct se_port *port)
1433 {
1434         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1435
1436         tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1437                                 GFP_KERNEL);
1438         if (!tg_pt_gp_mem) {
1439                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1440                 return ERR_PTR(-ENOMEM);
1441         }
1442         INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1443         spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1444         atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1445
1446         tg_pt_gp_mem->tg_pt = port;
1447         port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1448         atomic_set(&port->sep_tg_pt_gp_active, 1);
1449
1450         return tg_pt_gp_mem;
1451 }
1452
1453 void core_alua_free_tg_pt_gp(
1454         struct t10_alua_tg_pt_gp *tg_pt_gp)
1455 {
1456         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1457         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1458         /*
1459          * Once we have reached this point, config_item_put() has already
1460          * been called from target_core_alua_drop_tg_pt_gp().
1461          *
1462          * Here we remove *tg_pt_gp from the global list so that
1463          * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1464          * can be made while we are releasing struct t10_alua_tg_pt_gp.
1465          */
1466         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1467         list_del(&tg_pt_gp->tg_pt_gp_list);
1468         su_dev->t10_alua.alua_tg_pt_gps_counter--;
1469         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1470         /*
1471          * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1472          * core_alua_get_tg_pt_gp_by_name() in
1473          * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1474          * to be released with core_alua_put_tg_pt_gp_from_name().
1475          */
1476         while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1477                 cpu_relax();
1478         /*
1479          * Release reference to struct t10_alua_tg_pt_gp from all associated
1480          * struct se_port.
1481          */
1482         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1483         list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1484                         &tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1485                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1486                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1487                         tg_pt_gp->tg_pt_gp_members--;
1488                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1489                 }
1490                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1491                 /*
1492                  * tg_pt_gp_mem is associated with a single
1493                  * se_port->sep_alua_tg_pt_gp_mem, and is released via
1494                  * core_alua_free_tg_pt_gp_mem().
1495                  *
1496                  * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1497                  * assume we want to re-assocate a given tg_pt_gp_mem with
1498                  * default_tg_pt_gp.
1499                  */
1500                 spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1501                 if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
1502                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1503                                         su_dev->t10_alua.default_tg_pt_gp);
1504                 } else
1505                         tg_pt_gp_mem->tg_pt_gp = NULL;
1506                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1507
1508                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1509         }
1510         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1511
1512         kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1513 }
1514
1515 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1516 {
1517         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1518         struct t10_alua *alua = &su_dev->t10_alua;
1519         struct t10_alua_tg_pt_gp *tg_pt_gp;
1520         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1521
1522         if (alua->alua_type != SPC3_ALUA_EMULATED)
1523                 return;
1524
1525         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1526         if (!tg_pt_gp_mem)
1527                 return;
1528
1529         while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1530                 cpu_relax();
1531
1532         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1533         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1534         if (tg_pt_gp) {
1535                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1536                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1537                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1538                         tg_pt_gp->tg_pt_gp_members--;
1539                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1540                 }
1541                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1542                 tg_pt_gp_mem->tg_pt_gp = NULL;
1543         }
1544         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1545
1546         kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1547 }
1548
1549 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1550         struct se_subsystem_dev *su_dev,
1551         const char *name)
1552 {
1553         struct t10_alua_tg_pt_gp *tg_pt_gp;
1554         struct config_item *ci;
1555
1556         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1557         list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
1558                         tg_pt_gp_list) {
1559                 if (!tg_pt_gp->tg_pt_gp_valid_id)
1560                         continue;
1561                 ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1562                 if (!strcmp(config_item_name(ci), name)) {
1563                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1564                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1565                         return tg_pt_gp;
1566                 }
1567         }
1568         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1569
1570         return NULL;
1571 }
1572
1573 static void core_alua_put_tg_pt_gp_from_name(
1574         struct t10_alua_tg_pt_gp *tg_pt_gp)
1575 {
1576         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1577
1578         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1579         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1580         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1581 }
1582
1583 /*
1584  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1585  */
1586 void __core_alua_attach_tg_pt_gp_mem(
1587         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1588         struct t10_alua_tg_pt_gp *tg_pt_gp)
1589 {
1590         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1591         tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1592         tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1593         list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1594                         &tg_pt_gp->tg_pt_gp_mem_list);
1595         tg_pt_gp->tg_pt_gp_members++;
1596         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1597 }
1598
1599 /*
1600  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1601  */
1602 static void __core_alua_drop_tg_pt_gp_mem(
1603         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1604         struct t10_alua_tg_pt_gp *tg_pt_gp)
1605 {
1606         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1607         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1608         tg_pt_gp_mem->tg_pt_gp = NULL;
1609         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1610         tg_pt_gp->tg_pt_gp_members--;
1611         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1612 }
1613
1614 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1615 {
1616         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1617         struct config_item *tg_pt_ci;
1618         struct t10_alua *alua = &su_dev->t10_alua;
1619         struct t10_alua_tg_pt_gp *tg_pt_gp;
1620         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1621         ssize_t len = 0;
1622
1623         if (alua->alua_type != SPC3_ALUA_EMULATED)
1624                 return len;
1625
1626         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1627         if (!tg_pt_gp_mem)
1628                 return len;
1629
1630         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1631         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1632         if (tg_pt_gp) {
1633                 tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1634                 len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1635                         " %hu\nTG Port Primary Access State: %s\nTG Port "
1636                         "Primary Access Status: %s\nTG Port Secondary Access"
1637                         " State: %s\nTG Port Secondary Access Status: %s\n",
1638                         config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1639                         core_alua_dump_state(atomic_read(
1640                                         &tg_pt_gp->tg_pt_gp_alua_access_state)),
1641                         core_alua_dump_status(
1642                                 tg_pt_gp->tg_pt_gp_alua_access_status),
1643                         (atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1644                         "Offline" : "None",
1645                         core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1646         }
1647         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1648
1649         return len;
1650 }
1651
1652 ssize_t core_alua_store_tg_pt_gp_info(
1653         struct se_port *port,
1654         const char *page,
1655         size_t count)
1656 {
1657         struct se_portal_group *tpg;
1658         struct se_lun *lun;
1659         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1660         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1661         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1662         unsigned char buf[TG_PT_GROUP_NAME_BUF];
1663         int move = 0;
1664
1665         tpg = port->sep_tpg;
1666         lun = port->sep_lun;
1667
1668         if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
1669                 pr_warn("SPC3_ALUA_EMULATED not enabled for"
1670                         " %s/tpgt_%hu/%s\n", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1671                         tpg->se_tpg_tfo->tpg_get_tag(tpg),
1672                         config_item_name(&lun->lun_group.cg_item));
1673                 return -EINVAL;
1674         }
1675
1676         if (count > TG_PT_GROUP_NAME_BUF) {
1677                 pr_err("ALUA Target Port Group alias too large!\n");
1678                 return -EINVAL;
1679         }
1680         memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1681         memcpy(buf, page, count);
1682         /*
1683          * Any ALUA target port group alias besides "NULL" means we will be
1684          * making a new group association.
1685          */
1686         if (strcmp(strstrip(buf), "NULL")) {
1687                 /*
1688                  * core_alua_get_tg_pt_gp_by_name() will increment reference to
1689                  * struct t10_alua_tg_pt_gp.  This reference is released with
1690                  * core_alua_put_tg_pt_gp_from_name() below.
1691                  */
1692                 tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(su_dev,
1693                                         strstrip(buf));
1694                 if (!tg_pt_gp_new)
1695                         return -ENODEV;
1696         }
1697         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1698         if (!tg_pt_gp_mem) {
1699                 if (tg_pt_gp_new)
1700                         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1701                 pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
1702                 return -EINVAL;
1703         }
1704
1705         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1706         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1707         if (tg_pt_gp) {
1708                 /*
1709                  * Clearing an existing tg_pt_gp association, and replacing
1710                  * with the default_tg_pt_gp.
1711                  */
1712                 if (!tg_pt_gp_new) {
1713                         pr_debug("Target_Core_ConfigFS: Moving"
1714                                 " %s/tpgt_%hu/%s from ALUA Target Port Group:"
1715                                 " alua/%s, ID: %hu back to"
1716                                 " default_tg_pt_gp\n",
1717                                 tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1718                                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1719                                 config_item_name(&lun->lun_group.cg_item),
1720                                 config_item_name(
1721                                         &tg_pt_gp->tg_pt_gp_group.cg_item),
1722                                 tg_pt_gp->tg_pt_gp_id);
1723
1724                         __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1725                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1726                                         su_dev->t10_alua.default_tg_pt_gp);
1727                         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1728
1729                         return count;
1730                 }
1731                 /*
1732                  * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1733                  */
1734                 __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1735                 move = 1;
1736         }
1737         /*
1738          * Associate tg_pt_gp_mem with tg_pt_gp_new.
1739          */
1740         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1741         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1742         pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1743                 " Target Port Group: alua/%s, ID: %hu\n", (move) ?
1744                 "Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1745                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1746                 config_item_name(&lun->lun_group.cg_item),
1747                 config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1748                 tg_pt_gp_new->tg_pt_gp_id);
1749
1750         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1751         return count;
1752 }
1753
1754 ssize_t core_alua_show_access_type(
1755         struct t10_alua_tg_pt_gp *tg_pt_gp,
1756         char *page)
1757 {
1758         if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1759             (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1760                 return sprintf(page, "Implict and Explict\n");
1761         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1762                 return sprintf(page, "Implict\n");
1763         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1764                 return sprintf(page, "Explict\n");
1765         else
1766                 return sprintf(page, "None\n");
1767 }
1768
1769 ssize_t core_alua_store_access_type(
1770         struct t10_alua_tg_pt_gp *tg_pt_gp,
1771         const char *page,
1772         size_t count)
1773 {
1774         unsigned long tmp;
1775         int ret;
1776
1777         ret = strict_strtoul(page, 0, &tmp);
1778         if (ret < 0) {
1779                 pr_err("Unable to extract alua_access_type\n");
1780                 return -EINVAL;
1781         }
1782         if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1783                 pr_err("Illegal value for alua_access_type:"
1784                                 " %lu\n", tmp);
1785                 return -EINVAL;
1786         }
1787         if (tmp == 3)
1788                 tg_pt_gp->tg_pt_gp_alua_access_type =
1789                         TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1790         else if (tmp == 2)
1791                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1792         else if (tmp == 1)
1793                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1794         else
1795                 tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1796
1797         return count;
1798 }
1799
1800 ssize_t core_alua_show_nonop_delay_msecs(
1801         struct t10_alua_tg_pt_gp *tg_pt_gp,
1802         char *page)
1803 {
1804         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1805 }
1806
1807 ssize_t core_alua_store_nonop_delay_msecs(
1808         struct t10_alua_tg_pt_gp *tg_pt_gp,
1809         const char *page,
1810         size_t count)
1811 {
1812         unsigned long tmp;
1813         int ret;
1814
1815         ret = strict_strtoul(page, 0, &tmp);
1816         if (ret < 0) {
1817                 pr_err("Unable to extract nonop_delay_msecs\n");
1818                 return -EINVAL;
1819         }
1820         if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1821                 pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1822                         " ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1823                         ALUA_MAX_NONOP_DELAY_MSECS);
1824                 return -EINVAL;
1825         }
1826         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1827
1828         return count;
1829 }
1830
1831 ssize_t core_alua_show_trans_delay_msecs(
1832         struct t10_alua_tg_pt_gp *tg_pt_gp,
1833         char *page)
1834 {
1835         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1836 }
1837
1838 ssize_t core_alua_store_trans_delay_msecs(
1839         struct t10_alua_tg_pt_gp *tg_pt_gp,
1840         const char *page,
1841         size_t count)
1842 {
1843         unsigned long tmp;
1844         int ret;
1845
1846         ret = strict_strtoul(page, 0, &tmp);
1847         if (ret < 0) {
1848                 pr_err("Unable to extract trans_delay_msecs\n");
1849                 return -EINVAL;
1850         }
1851         if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1852                 pr_err("Passed trans_delay_msecs: %lu, exceeds"
1853                         " ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1854                         ALUA_MAX_TRANS_DELAY_MSECS);
1855                 return -EINVAL;
1856         }
1857         tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1858
1859         return count;
1860 }
1861
1862 ssize_t core_alua_show_preferred_bit(
1863         struct t10_alua_tg_pt_gp *tg_pt_gp,
1864         char *page)
1865 {
1866         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1867 }
1868
1869 ssize_t core_alua_store_preferred_bit(
1870         struct t10_alua_tg_pt_gp *tg_pt_gp,
1871         const char *page,
1872         size_t count)
1873 {
1874         unsigned long tmp;
1875         int ret;
1876
1877         ret = strict_strtoul(page, 0, &tmp);
1878         if (ret < 0) {
1879                 pr_err("Unable to extract preferred ALUA value\n");
1880                 return -EINVAL;
1881         }
1882         if ((tmp != 0) && (tmp != 1)) {
1883                 pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1884                 return -EINVAL;
1885         }
1886         tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1887
1888         return count;
1889 }
1890
1891 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1892 {
1893         if (!lun->lun_sep)
1894                 return -ENODEV;
1895
1896         return sprintf(page, "%d\n",
1897                 atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1898 }
1899
1900 ssize_t core_alua_store_offline_bit(
1901         struct se_lun *lun,
1902         const char *page,
1903         size_t count)
1904 {
1905         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1906         unsigned long tmp;
1907         int ret;
1908
1909         if (!lun->lun_sep)
1910                 return -ENODEV;
1911
1912         ret = strict_strtoul(page, 0, &tmp);
1913         if (ret < 0) {
1914                 pr_err("Unable to extract alua_tg_pt_offline value\n");
1915                 return -EINVAL;
1916         }
1917         if ((tmp != 0) && (tmp != 1)) {
1918                 pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1919                                 tmp);
1920                 return -EINVAL;
1921         }
1922         tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1923         if (!tg_pt_gp_mem) {
1924                 pr_err("Unable to locate *tg_pt_gp_mem\n");
1925                 return -EINVAL;
1926         }
1927
1928         ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1929                         lun->lun_sep, 0, (int)tmp);
1930         if (ret < 0)
1931                 return -EINVAL;
1932
1933         return count;
1934 }
1935
1936 ssize_t core_alua_show_secondary_status(
1937         struct se_lun *lun,
1938         char *page)
1939 {
1940         return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1941 }
1942
1943 ssize_t core_alua_store_secondary_status(
1944         struct se_lun *lun,
1945         const char *page,
1946         size_t count)
1947 {
1948         unsigned long tmp;
1949         int ret;
1950
1951         ret = strict_strtoul(page, 0, &tmp);
1952         if (ret < 0) {
1953                 pr_err("Unable to extract alua_tg_pt_status\n");
1954                 return -EINVAL;
1955         }
1956         if ((tmp != ALUA_STATUS_NONE) &&
1957             (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
1958             (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
1959                 pr_err("Illegal value for alua_tg_pt_status: %lu\n",
1960                                 tmp);
1961                 return -EINVAL;
1962         }
1963         lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
1964
1965         return count;
1966 }
1967
1968 ssize_t core_alua_show_secondary_write_metadata(
1969         struct se_lun *lun,
1970         char *page)
1971 {
1972         return sprintf(page, "%d\n",
1973                         lun->lun_sep->sep_tg_pt_secondary_write_md);
1974 }
1975
1976 ssize_t core_alua_store_secondary_write_metadata(
1977         struct se_lun *lun,
1978         const char *page,
1979         size_t count)
1980 {
1981         unsigned long tmp;
1982         int ret;
1983
1984         ret = strict_strtoul(page, 0, &tmp);
1985         if (ret < 0) {
1986                 pr_err("Unable to extract alua_tg_pt_write_md\n");
1987                 return -EINVAL;
1988         }
1989         if ((tmp != 0) && (tmp != 1)) {
1990                 pr_err("Illegal value for alua_tg_pt_write_md:"
1991                                 " %lu\n", tmp);
1992                 return -EINVAL;
1993         }
1994         lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
1995
1996         return count;
1997 }
1998
1999 int core_setup_alua(struct se_device *dev, int force_pt)
2000 {
2001         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
2002         struct t10_alua *alua = &su_dev->t10_alua;
2003         struct t10_alua_lu_gp_member *lu_gp_mem;
2004         /*
2005          * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
2006          * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
2007          * cause a problem because libata and some SATA RAID HBAs appear
2008          * under Linux/SCSI, but emulate SCSI logic themselves.
2009          */
2010         if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
2011             !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
2012                 alua->alua_type = SPC_ALUA_PASSTHROUGH;
2013                 alua->alua_state_check = &core_alua_state_check_nop;
2014                 pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
2015                         " emulation\n", dev->transport->name);
2016                 return 0;
2017         }
2018         /*
2019          * If SPC-3 or above is reported by real or emulated struct se_device,
2020          * use emulated ALUA.
2021          */
2022         if (dev->transport->get_device_rev(dev) >= SCSI_3) {
2023                 pr_debug("%s: Enabling ALUA Emulation for SPC-3"
2024                         " device\n", dev->transport->name);
2025                 /*
2026                  * Associate this struct se_device with the default ALUA
2027                  * LUN Group.
2028                  */
2029                 lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2030                 if (IS_ERR(lu_gp_mem))
2031                         return PTR_ERR(lu_gp_mem);
2032
2033                 alua->alua_type = SPC3_ALUA_EMULATED;
2034                 alua->alua_state_check = &core_alua_state_check;
2035                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2036                 __core_alua_attach_lu_gp_mem(lu_gp_mem,
2037                                 default_lu_gp);
2038                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2039
2040                 pr_debug("%s: Adding to default ALUA LU Group:"
2041                         " core/alua/lu_gps/default_lu_gp\n",
2042                         dev->transport->name);
2043         } else {
2044                 alua->alua_type = SPC2_ALUA_DISABLED;
2045                 alua->alua_state_check = &core_alua_state_check_nop;
2046                 pr_debug("%s: Disabling ALUA Emulation for SPC-2"
2047                         " device\n", dev->transport->name);
2048         }
2049
2050         return 0;
2051 }