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         list_del(&lu_gp->lu_gp_node);
1195         alua_lu_gps_count--;
1196         spin_unlock(&lu_gps_lock);
1197         /*
1198          * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1199          * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1200          * released with core_alua_put_lu_gp_from_name()
1201          */
1202         while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1203                 cpu_relax();
1204         /*
1205          * Release reference to struct t10_alua_lu_gp * from all associated
1206          * struct se_device.
1207          */
1208         spin_lock(&lu_gp->lu_gp_lock);
1209         list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1210                                 &lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1211                 if (lu_gp_mem->lu_gp_assoc) {
1212                         list_del(&lu_gp_mem->lu_gp_mem_list);
1213                         lu_gp->lu_gp_members--;
1214                         lu_gp_mem->lu_gp_assoc = 0;
1215                 }
1216                 spin_unlock(&lu_gp->lu_gp_lock);
1217                 /*
1218                  *
1219                  * lu_gp_mem is associated with a single
1220                  * struct se_device->dev_alua_lu_gp_mem, and is released when
1221                  * struct se_device is released via core_alua_free_lu_gp_mem().
1222                  *
1223                  * If the passed lu_gp does NOT match the default_lu_gp, assume
1224                  * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1225                  */
1226                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1227                 if (lu_gp != default_lu_gp)
1228                         __core_alua_attach_lu_gp_mem(lu_gp_mem,
1229                                         default_lu_gp);
1230                 else
1231                         lu_gp_mem->lu_gp = NULL;
1232                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1233
1234                 spin_lock(&lu_gp->lu_gp_lock);
1235         }
1236         spin_unlock(&lu_gp->lu_gp_lock);
1237
1238         kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1239 }
1240
1241 void core_alua_free_lu_gp_mem(struct se_device *dev)
1242 {
1243         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1244         struct t10_alua *alua = &su_dev->t10_alua;
1245         struct t10_alua_lu_gp *lu_gp;
1246         struct t10_alua_lu_gp_member *lu_gp_mem;
1247
1248         if (alua->alua_type != SPC3_ALUA_EMULATED)
1249                 return;
1250
1251         lu_gp_mem = dev->dev_alua_lu_gp_mem;
1252         if (!lu_gp_mem)
1253                 return;
1254
1255         while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1256                 cpu_relax();
1257
1258         spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1259         lu_gp = lu_gp_mem->lu_gp;
1260         if (lu_gp) {
1261                 spin_lock(&lu_gp->lu_gp_lock);
1262                 if (lu_gp_mem->lu_gp_assoc) {
1263                         list_del(&lu_gp_mem->lu_gp_mem_list);
1264                         lu_gp->lu_gp_members--;
1265                         lu_gp_mem->lu_gp_assoc = 0;
1266                 }
1267                 spin_unlock(&lu_gp->lu_gp_lock);
1268                 lu_gp_mem->lu_gp = NULL;
1269         }
1270         spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1271
1272         kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1273 }
1274
1275 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1276 {
1277         struct t10_alua_lu_gp *lu_gp;
1278         struct config_item *ci;
1279
1280         spin_lock(&lu_gps_lock);
1281         list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1282                 if (!lu_gp->lu_gp_valid_id)
1283                         continue;
1284                 ci = &lu_gp->lu_gp_group.cg_item;
1285                 if (!strcmp(config_item_name(ci), name)) {
1286                         atomic_inc(&lu_gp->lu_gp_ref_cnt);
1287                         spin_unlock(&lu_gps_lock);
1288                         return lu_gp;
1289                 }
1290         }
1291         spin_unlock(&lu_gps_lock);
1292
1293         return NULL;
1294 }
1295
1296 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1297 {
1298         spin_lock(&lu_gps_lock);
1299         atomic_dec(&lu_gp->lu_gp_ref_cnt);
1300         spin_unlock(&lu_gps_lock);
1301 }
1302
1303 /*
1304  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1305  */
1306 void __core_alua_attach_lu_gp_mem(
1307         struct t10_alua_lu_gp_member *lu_gp_mem,
1308         struct t10_alua_lu_gp *lu_gp)
1309 {
1310         spin_lock(&lu_gp->lu_gp_lock);
1311         lu_gp_mem->lu_gp = lu_gp;
1312         lu_gp_mem->lu_gp_assoc = 1;
1313         list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1314         lu_gp->lu_gp_members++;
1315         spin_unlock(&lu_gp->lu_gp_lock);
1316 }
1317
1318 /*
1319  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1320  */
1321 void __core_alua_drop_lu_gp_mem(
1322         struct t10_alua_lu_gp_member *lu_gp_mem,
1323         struct t10_alua_lu_gp *lu_gp)
1324 {
1325         spin_lock(&lu_gp->lu_gp_lock);
1326         list_del(&lu_gp_mem->lu_gp_mem_list);
1327         lu_gp_mem->lu_gp = NULL;
1328         lu_gp_mem->lu_gp_assoc = 0;
1329         lu_gp->lu_gp_members--;
1330         spin_unlock(&lu_gp->lu_gp_lock);
1331 }
1332
1333 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
1334         struct se_subsystem_dev *su_dev,
1335         const char *name,
1336         int def_group)
1337 {
1338         struct t10_alua_tg_pt_gp *tg_pt_gp;
1339
1340         tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1341         if (!tg_pt_gp) {
1342                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1343                 return NULL;
1344         }
1345         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1346         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1347         mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1348         spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1349         atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1350         tg_pt_gp->tg_pt_gp_su_dev = su_dev;
1351         tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1352         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1353                 ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1354         /*
1355          * Enable both explict and implict ALUA support by default
1356          */
1357         tg_pt_gp->tg_pt_gp_alua_access_type =
1358                         TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1359         /*
1360          * Set the default Active/NonOptimized Delay in milliseconds
1361          */
1362         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1363         tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1364
1365         if (def_group) {
1366                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1367                 tg_pt_gp->tg_pt_gp_id =
1368                                 su_dev->t10_alua.alua_tg_pt_gps_counter++;
1369                 tg_pt_gp->tg_pt_gp_valid_id = 1;
1370                 su_dev->t10_alua.alua_tg_pt_gps_count++;
1371                 list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1372                               &su_dev->t10_alua.tg_pt_gps_list);
1373                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1374         }
1375
1376         return tg_pt_gp;
1377 }
1378
1379 int core_alua_set_tg_pt_gp_id(
1380         struct t10_alua_tg_pt_gp *tg_pt_gp,
1381         u16 tg_pt_gp_id)
1382 {
1383         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1384         struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1385         u16 tg_pt_gp_id_tmp;
1386         /*
1387          * The tg_pt_gp->tg_pt_gp_id may only be set once..
1388          */
1389         if (tg_pt_gp->tg_pt_gp_valid_id) {
1390                 pr_warn("ALUA TG PT Group already has a valid ID,"
1391                         " ignoring request\n");
1392                 return -EINVAL;
1393         }
1394
1395         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1396         if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1397                 pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1398                         " 0x0000ffff reached\n");
1399                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1400                 kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1401                 return -ENOSPC;
1402         }
1403 again:
1404         tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1405                         su_dev->t10_alua.alua_tg_pt_gps_counter++;
1406
1407         list_for_each_entry(tg_pt_gp_tmp, &su_dev->t10_alua.tg_pt_gps_list,
1408                         tg_pt_gp_list) {
1409                 if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1410                         if (!tg_pt_gp_id)
1411                                 goto again;
1412
1413                         pr_err("ALUA Target Port Group ID: %hu already"
1414                                 " exists, ignoring request\n", tg_pt_gp_id);
1415                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1416                         return -EINVAL;
1417                 }
1418         }
1419
1420         tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1421         tg_pt_gp->tg_pt_gp_valid_id = 1;
1422         list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1423                         &su_dev->t10_alua.tg_pt_gps_list);
1424         su_dev->t10_alua.alua_tg_pt_gps_count++;
1425         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1426
1427         return 0;
1428 }
1429
1430 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1431         struct se_port *port)
1432 {
1433         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1434
1435         tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1436                                 GFP_KERNEL);
1437         if (!tg_pt_gp_mem) {
1438                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1439                 return ERR_PTR(-ENOMEM);
1440         }
1441         INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1442         spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1443         atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1444
1445         tg_pt_gp_mem->tg_pt = port;
1446         port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1447
1448         return tg_pt_gp_mem;
1449 }
1450
1451 void core_alua_free_tg_pt_gp(
1452         struct t10_alua_tg_pt_gp *tg_pt_gp)
1453 {
1454         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1455         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1456         /*
1457          * Once we have reached this point, config_item_put() has already
1458          * been called from target_core_alua_drop_tg_pt_gp().
1459          *
1460          * Here we remove *tg_pt_gp from the global list so that
1461          * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1462          * can be made while we are releasing struct t10_alua_tg_pt_gp.
1463          */
1464         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1465         list_del(&tg_pt_gp->tg_pt_gp_list);
1466         su_dev->t10_alua.alua_tg_pt_gps_counter--;
1467         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1468         /*
1469          * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1470          * core_alua_get_tg_pt_gp_by_name() in
1471          * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1472          * to be released with core_alua_put_tg_pt_gp_from_name().
1473          */
1474         while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1475                 cpu_relax();
1476         /*
1477          * Release reference to struct t10_alua_tg_pt_gp from all associated
1478          * struct se_port.
1479          */
1480         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1481         list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1482                         &tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1483                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1484                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1485                         tg_pt_gp->tg_pt_gp_members--;
1486                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1487                 }
1488                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1489                 /*
1490                  * tg_pt_gp_mem is associated with a single
1491                  * se_port->sep_alua_tg_pt_gp_mem, and is released via
1492                  * core_alua_free_tg_pt_gp_mem().
1493                  *
1494                  * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1495                  * assume we want to re-assocate a given tg_pt_gp_mem with
1496                  * default_tg_pt_gp.
1497                  */
1498                 spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1499                 if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
1500                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1501                                         su_dev->t10_alua.default_tg_pt_gp);
1502                 } else
1503                         tg_pt_gp_mem->tg_pt_gp = NULL;
1504                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1505
1506                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1507         }
1508         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1509
1510         kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1511 }
1512
1513 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1514 {
1515         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1516         struct t10_alua *alua = &su_dev->t10_alua;
1517         struct t10_alua_tg_pt_gp *tg_pt_gp;
1518         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1519
1520         if (alua->alua_type != SPC3_ALUA_EMULATED)
1521                 return;
1522
1523         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1524         if (!tg_pt_gp_mem)
1525                 return;
1526
1527         while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1528                 cpu_relax();
1529
1530         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1531         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1532         if (tg_pt_gp) {
1533                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1534                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1535                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1536                         tg_pt_gp->tg_pt_gp_members--;
1537                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1538                 }
1539                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1540                 tg_pt_gp_mem->tg_pt_gp = NULL;
1541         }
1542         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1543
1544         kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1545 }
1546
1547 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1548         struct se_subsystem_dev *su_dev,
1549         const char *name)
1550 {
1551         struct t10_alua_tg_pt_gp *tg_pt_gp;
1552         struct config_item *ci;
1553
1554         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1555         list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
1556                         tg_pt_gp_list) {
1557                 if (!tg_pt_gp->tg_pt_gp_valid_id)
1558                         continue;
1559                 ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1560                 if (!strcmp(config_item_name(ci), name)) {
1561                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1562                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1563                         return tg_pt_gp;
1564                 }
1565         }
1566         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1567
1568         return NULL;
1569 }
1570
1571 static void core_alua_put_tg_pt_gp_from_name(
1572         struct t10_alua_tg_pt_gp *tg_pt_gp)
1573 {
1574         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1575
1576         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1577         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1578         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1579 }
1580
1581 /*
1582  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1583  */
1584 void __core_alua_attach_tg_pt_gp_mem(
1585         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1586         struct t10_alua_tg_pt_gp *tg_pt_gp)
1587 {
1588         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1589         tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1590         tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1591         list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1592                         &tg_pt_gp->tg_pt_gp_mem_list);
1593         tg_pt_gp->tg_pt_gp_members++;
1594         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1595 }
1596
1597 /*
1598  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1599  */
1600 static void __core_alua_drop_tg_pt_gp_mem(
1601         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1602         struct t10_alua_tg_pt_gp *tg_pt_gp)
1603 {
1604         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1605         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1606         tg_pt_gp_mem->tg_pt_gp = NULL;
1607         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1608         tg_pt_gp->tg_pt_gp_members--;
1609         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1610 }
1611
1612 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1613 {
1614         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1615         struct config_item *tg_pt_ci;
1616         struct t10_alua *alua = &su_dev->t10_alua;
1617         struct t10_alua_tg_pt_gp *tg_pt_gp;
1618         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1619         ssize_t len = 0;
1620
1621         if (alua->alua_type != SPC3_ALUA_EMULATED)
1622                 return len;
1623
1624         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1625         if (!tg_pt_gp_mem)
1626                 return len;
1627
1628         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1629         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1630         if (tg_pt_gp) {
1631                 tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1632                 len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1633                         " %hu\nTG Port Primary Access State: %s\nTG Port "
1634                         "Primary Access Status: %s\nTG Port Secondary Access"
1635                         " State: %s\nTG Port Secondary Access Status: %s\n",
1636                         config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1637                         core_alua_dump_state(atomic_read(
1638                                         &tg_pt_gp->tg_pt_gp_alua_access_state)),
1639                         core_alua_dump_status(
1640                                 tg_pt_gp->tg_pt_gp_alua_access_status),
1641                         (atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1642                         "Offline" : "None",
1643                         core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1644         }
1645         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1646
1647         return len;
1648 }
1649
1650 ssize_t core_alua_store_tg_pt_gp_info(
1651         struct se_port *port,
1652         const char *page,
1653         size_t count)
1654 {
1655         struct se_portal_group *tpg;
1656         struct se_lun *lun;
1657         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1658         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1659         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1660         unsigned char buf[TG_PT_GROUP_NAME_BUF];
1661         int move = 0;
1662
1663         tpg = port->sep_tpg;
1664         lun = port->sep_lun;
1665
1666         if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
1667                 pr_warn("SPC3_ALUA_EMULATED not enabled for"
1668                         " %s/tpgt_%hu/%s\n", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1669                         tpg->se_tpg_tfo->tpg_get_tag(tpg),
1670                         config_item_name(&lun->lun_group.cg_item));
1671                 return -EINVAL;
1672         }
1673
1674         if (count > TG_PT_GROUP_NAME_BUF) {
1675                 pr_err("ALUA Target Port Group alias too large!\n");
1676                 return -EINVAL;
1677         }
1678         memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1679         memcpy(buf, page, count);
1680         /*
1681          * Any ALUA target port group alias besides "NULL" means we will be
1682          * making a new group association.
1683          */
1684         if (strcmp(strstrip(buf), "NULL")) {
1685                 /*
1686                  * core_alua_get_tg_pt_gp_by_name() will increment reference to
1687                  * struct t10_alua_tg_pt_gp.  This reference is released with
1688                  * core_alua_put_tg_pt_gp_from_name() below.
1689                  */
1690                 tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(su_dev,
1691                                         strstrip(buf));
1692                 if (!tg_pt_gp_new)
1693                         return -ENODEV;
1694         }
1695         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1696         if (!tg_pt_gp_mem) {
1697                 if (tg_pt_gp_new)
1698                         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1699                 pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
1700                 return -EINVAL;
1701         }
1702
1703         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1704         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1705         if (tg_pt_gp) {
1706                 /*
1707                  * Clearing an existing tg_pt_gp association, and replacing
1708                  * with the default_tg_pt_gp.
1709                  */
1710                 if (!tg_pt_gp_new) {
1711                         pr_debug("Target_Core_ConfigFS: Moving"
1712                                 " %s/tpgt_%hu/%s from ALUA Target Port Group:"
1713                                 " alua/%s, ID: %hu back to"
1714                                 " default_tg_pt_gp\n",
1715                                 tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1716                                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1717                                 config_item_name(&lun->lun_group.cg_item),
1718                                 config_item_name(
1719                                         &tg_pt_gp->tg_pt_gp_group.cg_item),
1720                                 tg_pt_gp->tg_pt_gp_id);
1721
1722                         __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1723                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1724                                         su_dev->t10_alua.default_tg_pt_gp);
1725                         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1726
1727                         return count;
1728                 }
1729                 /*
1730                  * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1731                  */
1732                 __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1733                 move = 1;
1734         }
1735         /*
1736          * Associate tg_pt_gp_mem with tg_pt_gp_new.
1737          */
1738         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1739         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1740         pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1741                 " Target Port Group: alua/%s, ID: %hu\n", (move) ?
1742                 "Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1743                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1744                 config_item_name(&lun->lun_group.cg_item),
1745                 config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1746                 tg_pt_gp_new->tg_pt_gp_id);
1747
1748         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1749         return count;
1750 }
1751
1752 ssize_t core_alua_show_access_type(
1753         struct t10_alua_tg_pt_gp *tg_pt_gp,
1754         char *page)
1755 {
1756         if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1757             (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1758                 return sprintf(page, "Implict and Explict\n");
1759         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1760                 return sprintf(page, "Implict\n");
1761         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1762                 return sprintf(page, "Explict\n");
1763         else
1764                 return sprintf(page, "None\n");
1765 }
1766
1767 ssize_t core_alua_store_access_type(
1768         struct t10_alua_tg_pt_gp *tg_pt_gp,
1769         const char *page,
1770         size_t count)
1771 {
1772         unsigned long tmp;
1773         int ret;
1774
1775         ret = strict_strtoul(page, 0, &tmp);
1776         if (ret < 0) {
1777                 pr_err("Unable to extract alua_access_type\n");
1778                 return -EINVAL;
1779         }
1780         if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1781                 pr_err("Illegal value for alua_access_type:"
1782                                 " %lu\n", tmp);
1783                 return -EINVAL;
1784         }
1785         if (tmp == 3)
1786                 tg_pt_gp->tg_pt_gp_alua_access_type =
1787                         TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1788         else if (tmp == 2)
1789                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1790         else if (tmp == 1)
1791                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1792         else
1793                 tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1794
1795         return count;
1796 }
1797
1798 ssize_t core_alua_show_nonop_delay_msecs(
1799         struct t10_alua_tg_pt_gp *tg_pt_gp,
1800         char *page)
1801 {
1802         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1803 }
1804
1805 ssize_t core_alua_store_nonop_delay_msecs(
1806         struct t10_alua_tg_pt_gp *tg_pt_gp,
1807         const char *page,
1808         size_t count)
1809 {
1810         unsigned long tmp;
1811         int ret;
1812
1813         ret = strict_strtoul(page, 0, &tmp);
1814         if (ret < 0) {
1815                 pr_err("Unable to extract nonop_delay_msecs\n");
1816                 return -EINVAL;
1817         }
1818         if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1819                 pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1820                         " ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1821                         ALUA_MAX_NONOP_DELAY_MSECS);
1822                 return -EINVAL;
1823         }
1824         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1825
1826         return count;
1827 }
1828
1829 ssize_t core_alua_show_trans_delay_msecs(
1830         struct t10_alua_tg_pt_gp *tg_pt_gp,
1831         char *page)
1832 {
1833         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1834 }
1835
1836 ssize_t core_alua_store_trans_delay_msecs(
1837         struct t10_alua_tg_pt_gp *tg_pt_gp,
1838         const char *page,
1839         size_t count)
1840 {
1841         unsigned long tmp;
1842         int ret;
1843
1844         ret = strict_strtoul(page, 0, &tmp);
1845         if (ret < 0) {
1846                 pr_err("Unable to extract trans_delay_msecs\n");
1847                 return -EINVAL;
1848         }
1849         if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1850                 pr_err("Passed trans_delay_msecs: %lu, exceeds"
1851                         " ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1852                         ALUA_MAX_TRANS_DELAY_MSECS);
1853                 return -EINVAL;
1854         }
1855         tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1856
1857         return count;
1858 }
1859
1860 ssize_t core_alua_show_preferred_bit(
1861         struct t10_alua_tg_pt_gp *tg_pt_gp,
1862         char *page)
1863 {
1864         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1865 }
1866
1867 ssize_t core_alua_store_preferred_bit(
1868         struct t10_alua_tg_pt_gp *tg_pt_gp,
1869         const char *page,
1870         size_t count)
1871 {
1872         unsigned long tmp;
1873         int ret;
1874
1875         ret = strict_strtoul(page, 0, &tmp);
1876         if (ret < 0) {
1877                 pr_err("Unable to extract preferred ALUA value\n");
1878                 return -EINVAL;
1879         }
1880         if ((tmp != 0) && (tmp != 1)) {
1881                 pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1882                 return -EINVAL;
1883         }
1884         tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1885
1886         return count;
1887 }
1888
1889 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1890 {
1891         if (!lun->lun_sep)
1892                 return -ENODEV;
1893
1894         return sprintf(page, "%d\n",
1895                 atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1896 }
1897
1898 ssize_t core_alua_store_offline_bit(
1899         struct se_lun *lun,
1900         const char *page,
1901         size_t count)
1902 {
1903         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1904         unsigned long tmp;
1905         int ret;
1906
1907         if (!lun->lun_sep)
1908                 return -ENODEV;
1909
1910         ret = strict_strtoul(page, 0, &tmp);
1911         if (ret < 0) {
1912                 pr_err("Unable to extract alua_tg_pt_offline value\n");
1913                 return -EINVAL;
1914         }
1915         if ((tmp != 0) && (tmp != 1)) {
1916                 pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1917                                 tmp);
1918                 return -EINVAL;
1919         }
1920         tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1921         if (!tg_pt_gp_mem) {
1922                 pr_err("Unable to locate *tg_pt_gp_mem\n");
1923                 return -EINVAL;
1924         }
1925
1926         ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1927                         lun->lun_sep, 0, (int)tmp);
1928         if (ret < 0)
1929                 return -EINVAL;
1930
1931         return count;
1932 }
1933
1934 ssize_t core_alua_show_secondary_status(
1935         struct se_lun *lun,
1936         char *page)
1937 {
1938         return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1939 }
1940
1941 ssize_t core_alua_store_secondary_status(
1942         struct se_lun *lun,
1943         const char *page,
1944         size_t count)
1945 {
1946         unsigned long tmp;
1947         int ret;
1948
1949         ret = strict_strtoul(page, 0, &tmp);
1950         if (ret < 0) {
1951                 pr_err("Unable to extract alua_tg_pt_status\n");
1952                 return -EINVAL;
1953         }
1954         if ((tmp != ALUA_STATUS_NONE) &&
1955             (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
1956             (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
1957                 pr_err("Illegal value for alua_tg_pt_status: %lu\n",
1958                                 tmp);
1959                 return -EINVAL;
1960         }
1961         lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
1962
1963         return count;
1964 }
1965
1966 ssize_t core_alua_show_secondary_write_metadata(
1967         struct se_lun *lun,
1968         char *page)
1969 {
1970         return sprintf(page, "%d\n",
1971                         lun->lun_sep->sep_tg_pt_secondary_write_md);
1972 }
1973
1974 ssize_t core_alua_store_secondary_write_metadata(
1975         struct se_lun *lun,
1976         const char *page,
1977         size_t count)
1978 {
1979         unsigned long tmp;
1980         int ret;
1981
1982         ret = strict_strtoul(page, 0, &tmp);
1983         if (ret < 0) {
1984                 pr_err("Unable to extract alua_tg_pt_write_md\n");
1985                 return -EINVAL;
1986         }
1987         if ((tmp != 0) && (tmp != 1)) {
1988                 pr_err("Illegal value for alua_tg_pt_write_md:"
1989                                 " %lu\n", tmp);
1990                 return -EINVAL;
1991         }
1992         lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
1993
1994         return count;
1995 }
1996
1997 int core_setup_alua(struct se_device *dev, int force_pt)
1998 {
1999         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
2000         struct t10_alua *alua = &su_dev->t10_alua;
2001         struct t10_alua_lu_gp_member *lu_gp_mem;
2002         /*
2003          * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
2004          * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
2005          * cause a problem because libata and some SATA RAID HBAs appear
2006          * under Linux/SCSI, but emulate SCSI logic themselves.
2007          */
2008         if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
2009             !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
2010                 alua->alua_type = SPC_ALUA_PASSTHROUGH;
2011                 alua->alua_state_check = &core_alua_state_check_nop;
2012                 pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
2013                         " emulation\n", dev->transport->name);
2014                 return 0;
2015         }
2016         /*
2017          * If SPC-3 or above is reported by real or emulated struct se_device,
2018          * use emulated ALUA.
2019          */
2020         if (dev->transport->get_device_rev(dev) >= SCSI_3) {
2021                 pr_debug("%s: Enabling ALUA Emulation for SPC-3"
2022                         " device\n", dev->transport->name);
2023                 /*
2024                  * Associate this struct se_device with the default ALUA
2025                  * LUN Group.
2026                  */
2027                 lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2028                 if (IS_ERR(lu_gp_mem))
2029                         return PTR_ERR(lu_gp_mem);
2030
2031                 alua->alua_type = SPC3_ALUA_EMULATED;
2032                 alua->alua_state_check = &core_alua_state_check;
2033                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2034                 __core_alua_attach_lu_gp_mem(lu_gp_mem,
2035                                 default_lu_gp);
2036                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2037
2038                 pr_debug("%s: Adding to default ALUA LU Group:"
2039                         " core/alua/lu_gps/default_lu_gp\n",
2040                         dev->transport->name);
2041         } else {
2042                 alua->alua_type = SPC2_ALUA_DISABLED;
2043                 alua->alua_state_check = &core_alua_state_check_nop;
2044                 pr_debug("%s: Disabling ALUA Emulation for SPC-2"
2045                         " device\n", dev->transport->name);
2046         }
2047
2048         return 0;
2049 }