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 #include <asm/unaligned.h>
  34
  35 #include <target/target_core_base.h>
  36 #include <target/target_core_device.h>
  37 #include <target/target_core_transport.h>
  38 #include <target/target_core_fabric_ops.h>
  39 #include <target/target_core_configfs.h>
  40
  41 #include "target_core_alua.h"
  42 #include "target_core_hba.h"
  43 #include "target_core_ua.h"
  44
  45 static int core_alua_check_transition(int state, int *primary);
  46 static int core_alua_set_tg_pt_secondary_state(
  47                 struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
  48                 struct se_port *port, int explict, int offline);
  49
  50 static u16 alua_lu_gps_counter;
  51 static u32 alua_lu_gps_count;
  52
  53 static DEFINE_SPINLOCK(lu_gps_lock);
  54 static LIST_HEAD(lu_gps_list);
  55
  56 struct t10_alua_lu_gp *default_lu_gp;
  57
  58 /*
  59  * REPORT_TARGET_PORT_GROUPS
  60  *
  61  * See spc4r17 section 6.27
  62  */
  63 int target_emulate_report_target_port_groups(struct se_task *task)
  64 {
  65         struct se_cmd *cmd = task->task_se_cmd;
  66         struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
  67         struct se_port *port;
  68         struct t10_alua_tg_pt_gp *tg_pt_gp;
  69         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
  70         unsigned char *buf;
  71         u32 rd_len = 0, off = 4; /* Skip over RESERVED area to first
  72                                     Target port group descriptor */
  73         /*
  74          * Need at least 4 bytes of response data or else we can't
  75          * even fit the return data length.
  76          */
  77         if (cmd->data_length < 4) {
  78                 pr_warn("REPORT TARGET PORT GROUPS allocation length %u"
  79                         " too small\n", cmd->data_length);
  80                 return -EINVAL;
  81         }
  82
  83         buf = transport_kmap_data_sg(cmd);
  84
  85         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
  86         list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
  87                         tg_pt_gp_list) {
  88                 /*
  89                  * Check if the Target port group and Target port descriptor list
  90                  * based on tg_pt_gp_members count will fit into the response payload.
  91                  * Otherwise, bump rd_len to let the initiator know we have exceeded
  92                  * the allocation length and the response is truncated.
  93                  */
  94                 if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
  95                      cmd->data_length) {
  96                         rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
  97                         continue;
  98                 }
  99                 /*
 100                  * PREF: Preferred target port bit, determine if this
 101                  * bit should be set for port group.
 102                  */
 103                 if (tg_pt_gp->tg_pt_gp_pref)
 104                         buf[off] = 0x80;
 105                 /*
 106                  * Set the ASYMMETRIC ACCESS State
 107                  */
 108                 buf[off++] |= (atomic_read(
 109                         &tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
 110                 /*
 111                  * Set supported ASYMMETRIC ACCESS State bits
 112                  */
 113                 buf[off] = 0x80; /* T_SUP */
 114                 buf[off] |= 0x40; /* O_SUP */
 115                 buf[off] |= 0x8; /* U_SUP */
 116                 buf[off] |= 0x4; /* S_SUP */
 117                 buf[off] |= 0x2; /* AN_SUP */
 118                 buf[off++] |= 0x1; /* AO_SUP */
 119                 /*
 120                  * TARGET PORT GROUP
 121                  */
 122                 buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
 123                 buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
 124
 125                 off++; /* Skip over Reserved */
 126                 /*
 127                  * STATUS CODE
 128                  */
 129                 buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
 130                 /*
 131                  * Vendor Specific field
 132                  */
 133                 buf[off++] = 0x00;
 134                 /*
 135                  * TARGET PORT COUNT
 136                  */
 137                 buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
 138                 rd_len += 8;
 139
 140                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 141                 list_for_each_entry(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
 142                                 tg_pt_gp_mem_list) {
 143                         port = tg_pt_gp_mem->tg_pt;
 144                         /*
 145                          * Start Target Port descriptor format
 146                          *
 147                          * See spc4r17 section 6.2.7 Table 247
 148                          */
 149                         off += 2; /* Skip over Obsolete */
 150                         /*
 151                          * Set RELATIVE TARGET PORT IDENTIFIER
 152                          */
 153                         buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
 154                         buf[off++] = (port->sep_rtpi & 0xff);
 155                         rd_len += 4;
 156                 }
 157                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 158         }
 159         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 160         /*
 161          * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 162          */
 163         buf[0] = ((rd_len >> 24) & 0xff);
 164         buf[1] = ((rd_len >> 16) & 0xff);
 165         buf[2] = ((rd_len >> 8) & 0xff);
 166         buf[3] = (rd_len & 0xff);
 167
 168         transport_kunmap_data_sg(cmd);
 169
 170         task->task_scsi_status = GOOD;
 171         transport_complete_task(task, 1);
 172         return 0;
 173 }
 174
 175 /*
 176  * SET_TARGET_PORT_GROUPS for explict ALUA operation.
 177  *
 178  * See spc4r17 section 6.35
 179  */
 180 int target_emulate_set_target_port_groups(struct se_task *task)
 181 {
 182         struct se_cmd *cmd = task->task_se_cmd;
 183         struct se_device *dev = cmd->se_dev;
 184         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
 185         struct se_port *port, *l_port = cmd->se_lun->lun_sep;
 186         struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
 187         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
 188         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
 189         unsigned char *buf;
 190         unsigned char *ptr;
 191         u32 len = 4; /* Skip over RESERVED area in header */
 192         int alua_access_state, primary = 0, rc;
 193         u16 tg_pt_id, rtpi;
 194
 195         if (!l_port) {
 196                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 197                 return -EINVAL;
 198         }
 199         buf = transport_kmap_data_sg(cmd);
 200
 201         /*
 202          * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
 203          * for the local tg_pt_gp.
 204          */
 205         l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
 206         if (!l_tg_pt_gp_mem) {
 207                 pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
 208                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 209                 rc = -EINVAL;
 210                 goto out;
 211         }
 212         spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 213         l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
 214         if (!l_tg_pt_gp) {
 215                 spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 216                 pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
 217                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 218                 rc = -EINVAL;
 219                 goto out;
 220         }
 221         rc = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
 222         spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 223
 224         if (!rc) {
 225                 pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
 226                                 " while TPGS_EXPLICT_ALUA is disabled\n");
 227                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 228                 rc = -EINVAL;
 229                 goto out;
 230         }
 231
 232         ptr = &buf[4]; /* Skip over RESERVED area in header */
 233
 234         while (len < cmd->data_length) {
 235                 alua_access_state = (ptr[0] & 0x0f);
 236                 /*
 237                  * Check the received ALUA access state, and determine if
 238                  * the state is a primary or secondary target port asymmetric
 239                  * access state.
 240                  */
 241                 rc = core_alua_check_transition(alua_access_state, &primary);
 242                 if (rc != 0) {
 243                         /*
 244                          * If the SET TARGET PORT GROUPS attempts to establish
 245                          * an invalid combination of target port asymmetric
 246                          * access states or attempts to establish an
 247                          * unsupported target port asymmetric access state,
 248                          * then the command shall be terminated with CHECK
 249                          * CONDITION status, with the sense key set to ILLEGAL
 250                          * REQUEST, and the additional sense code set to INVALID
 251                          * FIELD IN PARAMETER LIST.
 252                          */
 253                         cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 254                         rc = -EINVAL;
 255                         goto out;
 256                 }
 257                 rc = -1;
 258                 /*
 259                  * If the ASYMMETRIC ACCESS STATE field (see table 267)
 260                  * specifies a primary target port asymmetric access state,
 261                  * then the TARGET PORT GROUP OR TARGET PORT field specifies
 262                  * a primary target port group for which the primary target
 263                  * port asymmetric access state shall be changed. If the
 264                  * ASYMMETRIC ACCESS STATE field specifies a secondary target
 265                  * port asymmetric access state, then the TARGET PORT GROUP OR
 266                  * TARGET PORT field specifies the relative target port
 267                  * identifier (see 3.1.120) of the target port for which the
 268                  * secondary target port asymmetric access state shall be
 269                  * changed.
 270                  */
 271                 if (primary) {
 272                         tg_pt_id = get_unaligned_be16(ptr + 2);
 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 = get_unaligned_be16(ptr + 2);
 317                         /*
 318                          * Locate the matching relative target port identifer
 319                          * for the struct se_device storage object.
 320                          */
 321                         spin_lock(&dev->se_port_lock);
 322                         list_for_each_entry(port, &dev->dev_sep_list,
 323                                                         sep_list) {
 324                                 if (port->sep_rtpi != rtpi)
 325                                         continue;
 326
 327                                 tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 328                                 spin_unlock(&dev->se_port_lock);
 329
 330                                 rc = core_alua_set_tg_pt_secondary_state(
 331                                                 tg_pt_gp_mem, port, 1, 1);
 332
 333                                 spin_lock(&dev->se_port_lock);
 334                                 break;
 335                         }
 336                         spin_unlock(&dev->se_port_lock);
 337                         /*
 338                          * If not matching relative target port identifier can
 339                          * be located, throw an exception with ASCQ:
 340                          * INVALID_PARAMETER_LIST
 341                          */
 342                         if (rc != 0) {
 343                                 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 344                                 rc = -EINVAL;
 345                                 goto out;
 346                         }
 347                 }
 348
 349                 ptr += 4;
 350                 len += 4;
 351         }
 352
 353 out:
 354         transport_kunmap_data_sg(cmd);
 355         task->task_scsi_status = GOOD;
 356         transport_complete_task(task, 1);
 357         return 0;
 358 }
 359
 360 static inline int core_alua_state_nonoptimized(
 361         struct se_cmd *cmd,
 362         unsigned char *cdb,
 363         int nonop_delay_msecs,
 364         u8 *alua_ascq)
 365 {
 366         /*
 367          * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
 368          * later to determine if processing of this cmd needs to be
 369          * temporarily delayed for the Active/NonOptimized primary access state.
 370          */
 371         cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
 372         cmd->alua_nonop_delay = nonop_delay_msecs;
 373         return 0;
 374 }
 375
 376 static inline int core_alua_state_standby(
 377         struct se_cmd *cmd,
 378         unsigned char *cdb,
 379         u8 *alua_ascq)
 380 {
 381         /*
 382          * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
 383          * spc4r17 section 5.9.2.4.4
 384          */
 385         switch (cdb[0]) {
 386         case INQUIRY:
 387         case LOG_SELECT:
 388         case LOG_SENSE:
 389         case MODE_SELECT:
 390         case MODE_SENSE:
 391         case REPORT_LUNS:
 392         case RECEIVE_DIAGNOSTIC:
 393         case SEND_DIAGNOSTIC:
 394         case MAINTENANCE_IN:
 395                 switch (cdb[1]) {
 396                 case MI_REPORT_TARGET_PGS:
 397                         return 0;
 398                 default:
 399                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 400                         return 1;
 401                 }
 402         case MAINTENANCE_OUT:
 403                 switch (cdb[1]) {
 404                 case MO_SET_TARGET_PGS:
 405                         return 0;
 406                 default:
 407                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 408                         return 1;
 409                 }
 410         case REQUEST_SENSE:
 411         case PERSISTENT_RESERVE_IN:
 412         case PERSISTENT_RESERVE_OUT:
 413         case READ_BUFFER:
 414         case WRITE_BUFFER:
 415                 return 0;
 416         default:
 417                 *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 418                 return 1;
 419         }
 420
 421         return 0;
 422 }
 423
 424 static inline int core_alua_state_unavailable(
 425         struct se_cmd *cmd,
 426         unsigned char *cdb,
 427         u8 *alua_ascq)
 428 {
 429         /*
 430          * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
 431          * spc4r17 section 5.9.2.4.5
 432          */
 433         switch (cdb[0]) {
 434         case INQUIRY:
 435         case REPORT_LUNS:
 436         case MAINTENANCE_IN:
 437                 switch (cdb[1]) {
 438                 case MI_REPORT_TARGET_PGS:
 439                         return 0;
 440                 default:
 441                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 442                         return 1;
 443                 }
 444         case MAINTENANCE_OUT:
 445                 switch (cdb[1]) {
 446                 case MO_SET_TARGET_PGS:
 447                         return 0;
 448                 default:
 449                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 450                         return 1;
 451                 }
 452         case REQUEST_SENSE:
 453         case READ_BUFFER:
 454         case WRITE_BUFFER:
 455                 return 0;
 456         default:
 457                 *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 458                 return 1;
 459         }
 460
 461         return 0;
 462 }
 463
 464 static inline int core_alua_state_transition(
 465         struct se_cmd *cmd,
 466         unsigned char *cdb,
 467         u8 *alua_ascq)
 468 {
 469         /*
 470          * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
 471          * spc4r17 section 5.9.2.5
 472          */
 473         switch (cdb[0]) {
 474         case INQUIRY:
 475         case REPORT_LUNS:
 476         case MAINTENANCE_IN:
 477                 switch (cdb[1]) {
 478                 case MI_REPORT_TARGET_PGS:
 479                         return 0;
 480                 default:
 481                         *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 482                         return 1;
 483                 }
 484         case REQUEST_SENSE:
 485         case READ_BUFFER:
 486         case WRITE_BUFFER:
 487                 return 0;
 488         default:
 489                 *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 490                 return 1;
 491         }
 492
 493         return 0;
 494 }
 495
 496 /*
 497  * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
 498  * in transport_cmd_sequencer().  This function is assigned to
 499  * struct t10_alua *->state_check() in core_setup_alua()
 500  */
 501 static int core_alua_state_check_nop(
 502         struct se_cmd *cmd,
 503         unsigned char *cdb,
 504         u8 *alua_ascq)
 505 {
 506         return 0;
 507 }
 508
 509 /*
 510  * Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
 511  * This function is assigned to struct t10_alua *->state_check() in
 512  * core_setup_alua()
 513  *
 514  * Also, this function can return three different return codes to
 515  * signal transport_generic_cmd_sequencer()
 516  *
 517  * return 1: Is used to signal LUN not accecsable, and check condition/not ready
 518  * return 0: Used to signal success
 519  * reutrn -1: Used to signal failure, and invalid cdb field
 520  */
 521 static int core_alua_state_check(
 522         struct se_cmd *cmd,
 523         unsigned char *cdb,
 524         u8 *alua_ascq)
 525 {
 526         struct se_lun *lun = cmd->se_lun;
 527         struct se_port *port = lun->lun_sep;
 528         struct t10_alua_tg_pt_gp *tg_pt_gp;
 529         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
 530         int out_alua_state, nonop_delay_msecs;
 531
 532         if (!port)
 533                 return 0;
 534         /*
 535          * First, check for a struct se_port specific secondary ALUA target port
 536          * access state: OFFLINE
 537          */
 538         if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
 539                 *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 540                 pr_debug("ALUA: Got secondary offline status for local"
 541                                 " target port\n");
 542                 *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 543                 return 1;
 544         }
 545          /*
 546          * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
 547          * ALUA target port group, to obtain current ALUA access state.
 548          * Otherwise look for the underlying struct se_device association with
 549          * a ALUA logical unit group.
 550          */
 551         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 552         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 553         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
 554         out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 555         nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
 556         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 557         /*
 558          * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a separate conditional
 559          * statement so the compiler knows explicitly to check this case first.
 560          * For the Optimized ALUA access state case, we want to process the
 561          * incoming fabric cmd ASAP..
 562          */
 563         if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
 564                 return 0;
 565
 566         switch (out_alua_state) {
 567         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 568                 return core_alua_state_nonoptimized(cmd, cdb,
 569                                         nonop_delay_msecs, alua_ascq);
 570         case ALUA_ACCESS_STATE_STANDBY:
 571                 return core_alua_state_standby(cmd, cdb, alua_ascq);
 572         case ALUA_ACCESS_STATE_UNAVAILABLE:
 573                 return core_alua_state_unavailable(cmd, cdb, alua_ascq);
 574         case ALUA_ACCESS_STATE_TRANSITION:
 575                 return core_alua_state_transition(cmd, cdb, alua_ascq);
 576         /*
 577          * OFFLINE is a secondary ALUA target port group access state, that is
 578          * handled above with struct se_port->sep_tg_pt_secondary_offline=1
 579          */
 580         case ALUA_ACCESS_STATE_OFFLINE:
 581         default:
 582                 pr_err("Unknown ALUA access state: 0x%02x\n",
 583                                 out_alua_state);
 584                 return -EINVAL;
 585         }
 586
 587         return 0;
 588 }
 589
 590 /*
 591  * Check implict and explict ALUA state change request.
 592  */
 593 static int core_alua_check_transition(int state, int *primary)
 594 {
 595         switch (state) {
 596         case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 597         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 598         case ALUA_ACCESS_STATE_STANDBY:
 599         case ALUA_ACCESS_STATE_UNAVAILABLE:
 600                 /*
 601                  * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
 602                  * defined as primary target port asymmetric access states.
 603                  */
 604                 *primary = 1;
 605                 break;
 606         case ALUA_ACCESS_STATE_OFFLINE:
 607                 /*
 608                  * OFFLINE state is defined as a secondary target port
 609                  * asymmetric access state.
 610                  */
 611                 *primary = 0;
 612                 break;
 613         default:
 614                 pr_err("Unknown ALUA access state: 0x%02x\n", state);
 615                 return -EINVAL;
 616         }
 617
 618         return 0;
 619 }
 620
 621 static char *core_alua_dump_state(int state)
 622 {
 623         switch (state) {
 624         case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 625                 return "Active/Optimized";
 626         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 627                 return "Active/NonOptimized";
 628         case ALUA_ACCESS_STATE_STANDBY:
 629                 return "Standby";
 630         case ALUA_ACCESS_STATE_UNAVAILABLE:
 631                 return "Unavailable";
 632         case ALUA_ACCESS_STATE_OFFLINE:
 633                 return "Offline";
 634         default:
 635                 return "Unknown";
 636         }
 637
 638         return NULL;
 639 }
 640
 641 char *core_alua_dump_status(int status)
 642 {
 643         switch (status) {
 644         case ALUA_STATUS_NONE:
 645                 return "None";
 646         case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
 647                 return "Altered by Explict STPG";
 648         case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
 649                 return "Altered by Implict ALUA";
 650         default:
 651                 return "Unknown";
 652         }
 653
 654         return NULL;
 655 }
 656
 657 /*
 658  * Used by fabric modules to determine when we need to delay processing
 659  * for the Active/NonOptimized paths..
 660  */
 661 int core_alua_check_nonop_delay(
 662         struct se_cmd *cmd)
 663 {
 664         if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
 665                 return 0;
 666         if (in_interrupt())
 667                 return 0;
 668         /*
 669          * The ALUA Active/NonOptimized access state delay can be disabled
 670          * in via configfs with a value of zero
 671          */
 672         if (!cmd->alua_nonop_delay)
 673                 return 0;
 674         /*
 675          * struct se_cmd->alua_nonop_delay gets set by a target port group
 676          * defined interval in core_alua_state_nonoptimized()
 677          */
 678         msleep_interruptible(cmd->alua_nonop_delay);
 679         return 0;
 680 }
 681 EXPORT_SYMBOL(core_alua_check_nonop_delay);
 682
 683 /*
 684  * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
 685  *
 686  */
 687 static int core_alua_write_tpg_metadata(
 688         const char *path,
 689         unsigned char *md_buf,
 690         u32 md_buf_len)
 691 {
 692         mm_segment_t old_fs;
 693         struct file *file;
 694         struct iovec iov[1];
 695         int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
 696
 697         memset(iov, 0, sizeof(struct iovec));
 698
 699         file = filp_open(path, flags, 0600);
 700         if (IS_ERR(file) || !file || !file->f_dentry) {
 701                 pr_err("filp_open(%s) for ALUA metadata failed\n",
 702                         path);
 703                 return -ENODEV;
 704         }
 705
 706         iov[0].iov_base = &md_buf[0];
 707         iov[0].iov_len = md_buf_len;
 708
 709         old_fs = get_fs();
 710         set_fs(get_ds());
 711         ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
 712         set_fs(old_fs);
 713
 714         if (ret < 0) {
 715                 pr_err("Error writing ALUA metadata file: %s\n", path);
 716                 filp_close(file, NULL);
 717                 return -EIO;
 718         }
 719         filp_close(file, NULL);
 720
 721         return 0;
 722 }
 723
 724 /*
 725  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
 726  */
 727 static int core_alua_update_tpg_primary_metadata(
 728         struct t10_alua_tg_pt_gp *tg_pt_gp,
 729         int primary_state,
 730         unsigned char *md_buf)
 731 {
 732         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
 733         struct t10_wwn *wwn = &su_dev->t10_wwn;
 734         char path[ALUA_METADATA_PATH_LEN];
 735         int len;
 736
 737         memset(path, 0, ALUA_METADATA_PATH_LEN);
 738
 739         len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
 740                         "tg_pt_gp_id=%hu\n"
 741                         "alua_access_state=0x%02x\n"
 742                         "alua_access_status=0x%02x\n",
 743                         tg_pt_gp->tg_pt_gp_id, primary_state,
 744                         tg_pt_gp->tg_pt_gp_alua_access_status);
 745
 746         snprintf(path, ALUA_METADATA_PATH_LEN,
 747                 "/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
 748                 config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 749
 750         return core_alua_write_tpg_metadata(path, md_buf, len);
 751 }
 752
 753 static int core_alua_do_transition_tg_pt(
 754         struct t10_alua_tg_pt_gp *tg_pt_gp,
 755         struct se_port *l_port,
 756         struct se_node_acl *nacl,
 757         unsigned char *md_buf,
 758         int new_state,
 759         int explict)
 760 {
 761         struct se_dev_entry *se_deve;
 762         struct se_lun_acl *lacl;
 763         struct se_port *port;
 764         struct t10_alua_tg_pt_gp_member *mem;
 765         int old_state = 0;
 766         /*
 767          * Save the old primary ALUA access state, and set the current state
 768          * to ALUA_ACCESS_STATE_TRANSITION.
 769          */
 770         old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 771         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
 772                         ALUA_ACCESS_STATE_TRANSITION);
 773         tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
 774                                 ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
 775                                 ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
 776         /*
 777          * Check for the optional ALUA primary state transition delay
 778          */
 779         if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
 780                 msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
 781
 782         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 783         list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
 784                                 tg_pt_gp_mem_list) {
 785                 port = mem->tg_pt;
 786                 /*
 787                  * After an implicit target port asymmetric access state
 788                  * change, a device server shall establish a unit attention
 789                  * condition for the initiator port associated with every I_T
 790                  * nexus with the additional sense code set to ASYMMETRIC
 791                  * ACCESS STATE CHAGED.
 792                  *
 793                  * After an explicit target port asymmetric access state
 794                  * change, a device server shall establish a unit attention
 795                  * condition with the additional sense code set to ASYMMETRIC
 796                  * ACCESS STATE CHANGED for the initiator port associated with
 797                  * every I_T nexus other than the I_T nexus on which the SET
 798                  * TARGET PORT GROUPS command
 799                  */
 800                 atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
 801                 smp_mb__after_atomic_inc();
 802                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 803
 804                 spin_lock_bh(&port->sep_alua_lock);
 805                 list_for_each_entry(se_deve, &port->sep_alua_list,
 806                                         alua_port_list) {
 807                         lacl = se_deve->se_lun_acl;
 808                         /*
 809                          * se_deve->se_lun_acl pointer may be NULL for a
 810                          * entry created without explict Node+MappedLUN ACLs
 811                          */
 812                         if (!lacl)
 813                                 continue;
 814
 815                         if (explict &&
 816                            (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
 817                            (l_port != NULL) && (l_port == port))
 818                                 continue;
 819
 820                         core_scsi3_ua_allocate(lacl->se_lun_nacl,
 821                                 se_deve->mapped_lun, 0x2A,
 822                                 ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
 823                 }
 824                 spin_unlock_bh(&port->sep_alua_lock);
 825
 826                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 827                 atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
 828                 smp_mb__after_atomic_dec();
 829         }
 830         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 831         /*
 832          * Update the ALUA metadata buf that has been allocated in
 833          * core_alua_do_port_transition(), this metadata will be written
 834          * to struct file.
 835          *
 836          * Note that there is the case where we do not want to update the
 837          * metadata when the saved metadata is being parsed in userspace
 838          * when setting the existing port access state and access status.
 839          *
 840          * Also note that the failure to write out the ALUA metadata to
 841          * struct file does NOT affect the actual ALUA transition.
 842          */
 843         if (tg_pt_gp->tg_pt_gp_write_metadata) {
 844                 mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
 845                 core_alua_update_tpg_primary_metadata(tg_pt_gp,
 846                                         new_state, md_buf);
 847                 mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
 848         }
 849         /*
 850          * Set the current primary ALUA access state to the requested new state
 851          */
 852         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
 853
 854         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
 855                 " from primary access state %s to %s\n", (explict) ? "explict" :
 856                 "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
 857                 tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
 858                 core_alua_dump_state(new_state));
 859
 860         return 0;
 861 }
 862
 863 int core_alua_do_port_transition(
 864         struct t10_alua_tg_pt_gp *l_tg_pt_gp,
 865         struct se_device *l_dev,
 866         struct se_port *l_port,
 867         struct se_node_acl *l_nacl,
 868         int new_state,
 869         int explict)
 870 {
 871         struct se_device *dev;
 872         struct se_port *port;
 873         struct se_subsystem_dev *su_dev;
 874         struct se_node_acl *nacl;
 875         struct t10_alua_lu_gp *lu_gp;
 876         struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
 877         struct t10_alua_tg_pt_gp *tg_pt_gp;
 878         unsigned char *md_buf;
 879         int primary;
 880
 881         if (core_alua_check_transition(new_state, &primary) != 0)
 882                 return -EINVAL;
 883
 884         md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
 885         if (!md_buf) {
 886                 pr_err("Unable to allocate buf for ALUA metadata\n");
 887                 return -ENOMEM;
 888         }
 889
 890         local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
 891         spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
 892         lu_gp = local_lu_gp_mem->lu_gp;
 893         atomic_inc(&lu_gp->lu_gp_ref_cnt);
 894         smp_mb__after_atomic_inc();
 895         spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
 896         /*
 897          * For storage objects that are members of the 'default_lu_gp',
 898          * we only do transition on the passed *l_tp_pt_gp, and not
 899          * on all of the matching target port groups IDs in default_lu_gp.
 900          */
 901         if (!lu_gp->lu_gp_id) {
 902                 /*
 903                  * core_alua_do_transition_tg_pt() will always return
 904                  * success.
 905                  */
 906                 core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
 907                                         md_buf, new_state, explict);
 908                 atomic_dec(&lu_gp->lu_gp_ref_cnt);
 909                 smp_mb__after_atomic_dec();
 910                 kfree(md_buf);
 911                 return 0;
 912         }
 913         /*
 914          * For all other LU groups aside from 'default_lu_gp', walk all of
 915          * the associated storage objects looking for a matching target port
 916          * group ID from the local target port group.
 917          */
 918         spin_lock(&lu_gp->lu_gp_lock);
 919         list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
 920                                 lu_gp_mem_list) {
 921
 922                 dev = lu_gp_mem->lu_gp_mem_dev;
 923                 su_dev = dev->se_sub_dev;
 924                 atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
 925                 smp_mb__after_atomic_inc();
 926                 spin_unlock(&lu_gp->lu_gp_lock);
 927
 928                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 929                 list_for_each_entry(tg_pt_gp,
 930                                 &su_dev->t10_alua.tg_pt_gps_list,
 931                                 tg_pt_gp_list) {
 932
 933                         if (!tg_pt_gp->tg_pt_gp_valid_id)
 934                                 continue;
 935                         /*
 936                          * If the target behavior port asymmetric access state
 937                          * is changed for any target port group accessiable via
 938                          * a logical unit within a LU group, the target port
 939                          * behavior group asymmetric access states for the same
 940                          * target port group accessible via other logical units
 941                          * in that LU group will also change.
 942                          */
 943                         if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
 944                                 continue;
 945
 946                         if (l_tg_pt_gp == tg_pt_gp) {
 947                                 port = l_port;
 948                                 nacl = l_nacl;
 949                         } else {
 950                                 port = NULL;
 951                                 nacl = NULL;
 952                         }
 953                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 954                         smp_mb__after_atomic_inc();
 955                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 956                         /*
 957                          * core_alua_do_transition_tg_pt() will always return
 958                          * success.
 959                          */
 960                         core_alua_do_transition_tg_pt(tg_pt_gp, port,
 961                                         nacl, md_buf, new_state, explict);
 962
 963                         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 964                         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
 965                         smp_mb__after_atomic_dec();
 966                 }
 967                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 968
 969                 spin_lock(&lu_gp->lu_gp_lock);
 970                 atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
 971                 smp_mb__after_atomic_dec();
 972         }
 973         spin_unlock(&lu_gp->lu_gp_lock);
 974
 975         pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
 976                 " Group IDs: %hu %s transition to primary state: %s\n",
 977                 config_item_name(&lu_gp->lu_gp_group.cg_item),
 978                 l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
 979                 core_alua_dump_state(new_state));
 980
 981         atomic_dec(&lu_gp->lu_gp_ref_cnt);
 982         smp_mb__after_atomic_dec();
 983         kfree(md_buf);
 984         return 0;
 985 }
 986
 987 /*
 988  * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
 989  */
 990 static int core_alua_update_tpg_secondary_metadata(
 991         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
 992         struct se_port *port,
 993         unsigned char *md_buf,
 994         u32 md_buf_len)
 995 {
 996         struct se_portal_group *se_tpg = port->sep_tpg;
 997         char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
 998         int len;
 999
1000         memset(path, 0, ALUA_METADATA_PATH_LEN);
1001         memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1002
1003         len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1004                         se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1005
1006         if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1007                 snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1008                                 se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1009
1010         len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1011                         "alua_tg_pt_status=0x%02x\n",
1012                         atomic_read(&port->sep_tg_pt_secondary_offline),
1013                         port->sep_tg_pt_secondary_stat);
1014
1015         snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1016                         se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1017                         port->sep_lun->unpacked_lun);
1018
1019         return core_alua_write_tpg_metadata(path, md_buf, len);
1020 }
1021
1022 static int core_alua_set_tg_pt_secondary_state(
1023         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1024         struct se_port *port,
1025         int explict,
1026         int offline)
1027 {
1028         struct t10_alua_tg_pt_gp *tg_pt_gp;
1029         unsigned char *md_buf;
1030         u32 md_buf_len;
1031         int trans_delay_msecs;
1032
1033         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1034         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1035         if (!tg_pt_gp) {
1036                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1037                 pr_err("Unable to complete secondary state"
1038                                 " transition\n");
1039                 return -EINVAL;
1040         }
1041         trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1042         /*
1043          * Set the secondary ALUA target port access state to OFFLINE
1044          * or release the previously secondary state for struct se_port
1045          */
1046         if (offline)
1047                 atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1048         else
1049                 atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1050
1051         md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1052         port->sep_tg_pt_secondary_stat = (explict) ?
1053                         ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
1054                         ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
1055
1056         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1057                 " to secondary access state: %s\n", (explict) ? "explict" :
1058                 "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1059                 tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1060
1061         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1062         /*
1063          * Do the optional transition delay after we set the secondary
1064          * ALUA access state.
1065          */
1066         if (trans_delay_msecs != 0)
1067                 msleep_interruptible(trans_delay_msecs);
1068         /*
1069          * See if we need to update the ALUA fabric port metadata for
1070          * secondary state and status
1071          */
1072         if (port->sep_tg_pt_secondary_write_md) {
1073                 md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1074                 if (!md_buf) {
1075                         pr_err("Unable to allocate md_buf for"
1076                                 " secondary ALUA access metadata\n");
1077                         return -ENOMEM;
1078                 }
1079                 mutex_lock(&port->sep_tg_pt_md_mutex);
1080                 core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1081                                 md_buf, md_buf_len);
1082                 mutex_unlock(&port->sep_tg_pt_md_mutex);
1083
1084                 kfree(md_buf);
1085         }
1086
1087         return 0;
1088 }
1089
1090 struct t10_alua_lu_gp *
1091 core_alua_allocate_lu_gp(const char *name, int def_group)
1092 {
1093         struct t10_alua_lu_gp *lu_gp;
1094
1095         lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1096         if (!lu_gp) {
1097                 pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1098                 return ERR_PTR(-ENOMEM);
1099         }
1100         INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1101         INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1102         spin_lock_init(&lu_gp->lu_gp_lock);
1103         atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1104
1105         if (def_group) {
1106                 lu_gp->lu_gp_id = alua_lu_gps_counter++;
1107                 lu_gp->lu_gp_valid_id = 1;
1108                 alua_lu_gps_count++;
1109         }
1110
1111         return lu_gp;
1112 }
1113
1114 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1115 {
1116         struct t10_alua_lu_gp *lu_gp_tmp;
1117         u16 lu_gp_id_tmp;
1118         /*
1119          * The lu_gp->lu_gp_id may only be set once..
1120          */
1121         if (lu_gp->lu_gp_valid_id) {
1122                 pr_warn("ALUA LU Group already has a valid ID,"
1123                         " ignoring request\n");
1124                 return -EINVAL;
1125         }
1126
1127         spin_lock(&lu_gps_lock);
1128         if (alua_lu_gps_count == 0x0000ffff) {
1129                 pr_err("Maximum ALUA alua_lu_gps_count:"
1130                                 " 0x0000ffff reached\n");
1131                 spin_unlock(&lu_gps_lock);
1132                 kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1133                 return -ENOSPC;
1134         }
1135 again:
1136         lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1137                                 alua_lu_gps_counter++;
1138
1139         list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1140                 if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1141                         if (!lu_gp_id)
1142                                 goto again;
1143
1144                         pr_warn("ALUA Logical Unit Group ID: %hu"
1145                                 " already exists, ignoring request\n",
1146                                 lu_gp_id);
1147                         spin_unlock(&lu_gps_lock);
1148                         return -EINVAL;
1149                 }
1150         }
1151
1152         lu_gp->lu_gp_id = lu_gp_id_tmp;
1153         lu_gp->lu_gp_valid_id = 1;
1154         list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1155         alua_lu_gps_count++;
1156         spin_unlock(&lu_gps_lock);
1157
1158         return 0;
1159 }
1160
1161 static struct t10_alua_lu_gp_member *
1162 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1163 {
1164         struct t10_alua_lu_gp_member *lu_gp_mem;
1165
1166         lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1167         if (!lu_gp_mem) {
1168                 pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1169                 return ERR_PTR(-ENOMEM);
1170         }
1171         INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1172         spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1173         atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1174
1175         lu_gp_mem->lu_gp_mem_dev = dev;
1176         dev->dev_alua_lu_gp_mem = lu_gp_mem;
1177
1178         return lu_gp_mem;
1179 }
1180
1181 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1182 {
1183         struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1184         /*
1185          * Once we have reached this point, config_item_put() has
1186          * already been called from target_core_alua_drop_lu_gp().
1187          *
1188          * Here, we remove the *lu_gp from the global list so that
1189          * no associations can be made while we are releasing
1190          * struct t10_alua_lu_gp.
1191          */
1192         spin_lock(&lu_gps_lock);
1193         list_del(&lu_gp->lu_gp_node);
1194         alua_lu_gps_count--;
1195         spin_unlock(&lu_gps_lock);
1196         /*
1197          * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1198          * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1199          * released with core_alua_put_lu_gp_from_name()
1200          */
1201         while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1202                 cpu_relax();
1203         /*
1204          * Release reference to struct t10_alua_lu_gp * from all associated
1205          * struct se_device.
1206          */
1207         spin_lock(&lu_gp->lu_gp_lock);
1208         list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1209                                 &lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1210                 if (lu_gp_mem->lu_gp_assoc) {
1211                         list_del(&lu_gp_mem->lu_gp_mem_list);
1212                         lu_gp->lu_gp_members--;
1213                         lu_gp_mem->lu_gp_assoc = 0;
1214                 }
1215                 spin_unlock(&lu_gp->lu_gp_lock);
1216                 /*
1217                  *
1218                  * lu_gp_mem is associated with a single
1219                  * struct se_device->dev_alua_lu_gp_mem, and is released when
1220                  * struct se_device is released via core_alua_free_lu_gp_mem().
1221                  *
1222                  * If the passed lu_gp does NOT match the default_lu_gp, assume
1223                  * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1224                  */
1225                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1226                 if (lu_gp != default_lu_gp)
1227                         __core_alua_attach_lu_gp_mem(lu_gp_mem,
1228                                         default_lu_gp);
1229                 else
1230                         lu_gp_mem->lu_gp = NULL;
1231                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1232
1233                 spin_lock(&lu_gp->lu_gp_lock);
1234         }
1235         spin_unlock(&lu_gp->lu_gp_lock);
1236
1237         kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1238 }
1239
1240 void core_alua_free_lu_gp_mem(struct se_device *dev)
1241 {
1242         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1243         struct t10_alua *alua = &su_dev->t10_alua;
1244         struct t10_alua_lu_gp *lu_gp;
1245         struct t10_alua_lu_gp_member *lu_gp_mem;
1246
1247         if (alua->alua_type != SPC3_ALUA_EMULATED)
1248                 return;
1249
1250         lu_gp_mem = dev->dev_alua_lu_gp_mem;
1251         if (!lu_gp_mem)
1252                 return;
1253
1254         while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1255                 cpu_relax();
1256
1257         spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1258         lu_gp = lu_gp_mem->lu_gp;
1259         if (lu_gp) {
1260                 spin_lock(&lu_gp->lu_gp_lock);
1261                 if (lu_gp_mem->lu_gp_assoc) {
1262                         list_del(&lu_gp_mem->lu_gp_mem_list);
1263                         lu_gp->lu_gp_members--;
1264                         lu_gp_mem->lu_gp_assoc = 0;
1265                 }
1266                 spin_unlock(&lu_gp->lu_gp_lock);
1267                 lu_gp_mem->lu_gp = NULL;
1268         }
1269         spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1270
1271         kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1272 }
1273
1274 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1275 {
1276         struct t10_alua_lu_gp *lu_gp;
1277         struct config_item *ci;
1278
1279         spin_lock(&lu_gps_lock);
1280         list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1281                 if (!lu_gp->lu_gp_valid_id)
1282                         continue;
1283                 ci = &lu_gp->lu_gp_group.cg_item;
1284                 if (!strcmp(config_item_name(ci), name)) {
1285                         atomic_inc(&lu_gp->lu_gp_ref_cnt);
1286                         spin_unlock(&lu_gps_lock);
1287                         return lu_gp;
1288                 }
1289         }
1290         spin_unlock(&lu_gps_lock);
1291
1292         return NULL;
1293 }
1294
1295 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1296 {
1297         spin_lock(&lu_gps_lock);
1298         atomic_dec(&lu_gp->lu_gp_ref_cnt);
1299         spin_unlock(&lu_gps_lock);
1300 }
1301
1302 /*
1303  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1304  */
1305 void __core_alua_attach_lu_gp_mem(
1306         struct t10_alua_lu_gp_member *lu_gp_mem,
1307         struct t10_alua_lu_gp *lu_gp)
1308 {
1309         spin_lock(&lu_gp->lu_gp_lock);
1310         lu_gp_mem->lu_gp = lu_gp;
1311         lu_gp_mem->lu_gp_assoc = 1;
1312         list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1313         lu_gp->lu_gp_members++;
1314         spin_unlock(&lu_gp->lu_gp_lock);
1315 }
1316
1317 /*
1318  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1319  */
1320 void __core_alua_drop_lu_gp_mem(
1321         struct t10_alua_lu_gp_member *lu_gp_mem,
1322         struct t10_alua_lu_gp *lu_gp)
1323 {
1324         spin_lock(&lu_gp->lu_gp_lock);
1325         list_del(&lu_gp_mem->lu_gp_mem_list);
1326         lu_gp_mem->lu_gp = NULL;
1327         lu_gp_mem->lu_gp_assoc = 0;
1328         lu_gp->lu_gp_members--;
1329         spin_unlock(&lu_gp->lu_gp_lock);
1330 }
1331
1332 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
1333         struct se_subsystem_dev *su_dev,
1334         const char *name,
1335         int def_group)
1336 {
1337         struct t10_alua_tg_pt_gp *tg_pt_gp;
1338
1339         tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1340         if (!tg_pt_gp) {
1341                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1342                 return NULL;
1343         }
1344         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1345         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1346         mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1347         spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1348         atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1349         tg_pt_gp->tg_pt_gp_su_dev = su_dev;
1350         tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1351         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1352                 ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1353         /*
1354          * Enable both explict and implict ALUA support by default
1355          */
1356         tg_pt_gp->tg_pt_gp_alua_access_type =
1357                         TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1358         /*
1359          * Set the default Active/NonOptimized Delay in milliseconds
1360          */
1361         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1362         tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1363
1364         if (def_group) {
1365                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1366                 tg_pt_gp->tg_pt_gp_id =
1367                                 su_dev->t10_alua.alua_tg_pt_gps_counter++;
1368                 tg_pt_gp->tg_pt_gp_valid_id = 1;
1369                 su_dev->t10_alua.alua_tg_pt_gps_count++;
1370                 list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1371                               &su_dev->t10_alua.tg_pt_gps_list);
1372                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1373         }
1374
1375         return tg_pt_gp;
1376 }
1377
1378 int core_alua_set_tg_pt_gp_id(
1379         struct t10_alua_tg_pt_gp *tg_pt_gp,
1380         u16 tg_pt_gp_id)
1381 {
1382         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1383         struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1384         u16 tg_pt_gp_id_tmp;
1385         /*
1386          * The tg_pt_gp->tg_pt_gp_id may only be set once..
1387          */
1388         if (tg_pt_gp->tg_pt_gp_valid_id) {
1389                 pr_warn("ALUA TG PT Group already has a valid ID,"
1390                         " ignoring request\n");
1391                 return -EINVAL;
1392         }
1393
1394         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1395         if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1396                 pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1397                         " 0x0000ffff reached\n");
1398                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1399                 kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1400                 return -ENOSPC;
1401         }
1402 again:
1403         tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1404                         su_dev->t10_alua.alua_tg_pt_gps_counter++;
1405
1406         list_for_each_entry(tg_pt_gp_tmp, &su_dev->t10_alua.tg_pt_gps_list,
1407                         tg_pt_gp_list) {
1408                 if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1409                         if (!tg_pt_gp_id)
1410                                 goto again;
1411
1412                         pr_err("ALUA Target Port Group ID: %hu already"
1413                                 " exists, ignoring request\n", tg_pt_gp_id);
1414                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1415                         return -EINVAL;
1416                 }
1417         }
1418
1419         tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1420         tg_pt_gp->tg_pt_gp_valid_id = 1;
1421         list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1422                         &su_dev->t10_alua.tg_pt_gps_list);
1423         su_dev->t10_alua.alua_tg_pt_gps_count++;
1424         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1425
1426         return 0;
1427 }
1428
1429 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1430         struct se_port *port)
1431 {
1432         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1433
1434         tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1435                                 GFP_KERNEL);
1436         if (!tg_pt_gp_mem) {
1437                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1438                 return ERR_PTR(-ENOMEM);
1439         }
1440         INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1441         spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1442         atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1443
1444         tg_pt_gp_mem->tg_pt = port;
1445         port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1446
1447         return tg_pt_gp_mem;
1448 }
1449
1450 void core_alua_free_tg_pt_gp(
1451         struct t10_alua_tg_pt_gp *tg_pt_gp)
1452 {
1453         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1454         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1455         /*
1456          * Once we have reached this point, config_item_put() has already
1457          * been called from target_core_alua_drop_tg_pt_gp().
1458          *
1459          * Here we remove *tg_pt_gp from the global list so that
1460          * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1461          * can be made while we are releasing struct t10_alua_tg_pt_gp.
1462          */
1463         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1464         list_del(&tg_pt_gp->tg_pt_gp_list);
1465         su_dev->t10_alua.alua_tg_pt_gps_counter--;
1466         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1467         /*
1468          * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1469          * core_alua_get_tg_pt_gp_by_name() in
1470          * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1471          * to be released with core_alua_put_tg_pt_gp_from_name().
1472          */
1473         while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1474                 cpu_relax();
1475         /*
1476          * Release reference to struct t10_alua_tg_pt_gp from all associated
1477          * struct se_port.
1478          */
1479         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1480         list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1481                         &tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1482                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1483                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1484                         tg_pt_gp->tg_pt_gp_members--;
1485                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1486                 }
1487                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1488                 /*
1489                  * tg_pt_gp_mem is associated with a single
1490                  * se_port->sep_alua_tg_pt_gp_mem, and is released via
1491                  * core_alua_free_tg_pt_gp_mem().
1492                  *
1493                  * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1494                  * assume we want to re-assocate a given tg_pt_gp_mem with
1495                  * default_tg_pt_gp.
1496                  */
1497                 spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1498                 if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
1499                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1500                                         su_dev->t10_alua.default_tg_pt_gp);
1501                 } else
1502                         tg_pt_gp_mem->tg_pt_gp = NULL;
1503                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1504
1505                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1506         }
1507         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1508
1509         kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1510 }
1511
1512 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1513 {
1514         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1515         struct t10_alua *alua = &su_dev->t10_alua;
1516         struct t10_alua_tg_pt_gp *tg_pt_gp;
1517         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1518
1519         if (alua->alua_type != SPC3_ALUA_EMULATED)
1520                 return;
1521
1522         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1523         if (!tg_pt_gp_mem)
1524                 return;
1525
1526         while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1527                 cpu_relax();
1528
1529         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1530         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1531         if (tg_pt_gp) {
1532                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1533                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1534                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1535                         tg_pt_gp->tg_pt_gp_members--;
1536                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1537                 }
1538                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1539                 tg_pt_gp_mem->tg_pt_gp = NULL;
1540         }
1541         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1542
1543         kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1544 }
1545
1546 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1547         struct se_subsystem_dev *su_dev,
1548         const char *name)
1549 {
1550         struct t10_alua_tg_pt_gp *tg_pt_gp;
1551         struct config_item *ci;
1552
1553         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1554         list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
1555                         tg_pt_gp_list) {
1556                 if (!tg_pt_gp->tg_pt_gp_valid_id)
1557                         continue;
1558                 ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1559                 if (!strcmp(config_item_name(ci), name)) {
1560                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1561                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1562                         return tg_pt_gp;
1563                 }
1564         }
1565         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1566
1567         return NULL;
1568 }
1569
1570 static void core_alua_put_tg_pt_gp_from_name(
1571         struct t10_alua_tg_pt_gp *tg_pt_gp)
1572 {
1573         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1574
1575         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1576         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1577         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1578 }
1579
1580 /*
1581  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1582  */
1583 void __core_alua_attach_tg_pt_gp_mem(
1584         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1585         struct t10_alua_tg_pt_gp *tg_pt_gp)
1586 {
1587         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1588         tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1589         tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1590         list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1591                         &tg_pt_gp->tg_pt_gp_mem_list);
1592         tg_pt_gp->tg_pt_gp_members++;
1593         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1594 }
1595
1596 /*
1597  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1598  */
1599 static void __core_alua_drop_tg_pt_gp_mem(
1600         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1601         struct t10_alua_tg_pt_gp *tg_pt_gp)
1602 {
1603         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1604         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1605         tg_pt_gp_mem->tg_pt_gp = NULL;
1606         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1607         tg_pt_gp->tg_pt_gp_members--;
1608         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1609 }
1610
1611 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1612 {
1613         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1614         struct config_item *tg_pt_ci;
1615         struct t10_alua *alua = &su_dev->t10_alua;
1616         struct t10_alua_tg_pt_gp *tg_pt_gp;
1617         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1618         ssize_t len = 0;
1619
1620         if (alua->alua_type != SPC3_ALUA_EMULATED)
1621                 return len;
1622
1623         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1624         if (!tg_pt_gp_mem)
1625                 return len;
1626
1627         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1628         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1629         if (tg_pt_gp) {
1630                 tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1631                 len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1632                         " %hu\nTG Port Primary Access State: %s\nTG Port "
1633                         "Primary Access Status: %s\nTG Port Secondary Access"
1634                         " State: %s\nTG Port Secondary Access Status: %s\n",
1635                         config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1636                         core_alua_dump_state(atomic_read(
1637                                         &tg_pt_gp->tg_pt_gp_alua_access_state)),
1638                         core_alua_dump_status(
1639                                 tg_pt_gp->tg_pt_gp_alua_access_status),
1640                         (atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1641                         "Offline" : "None",
1642                         core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1643         }
1644         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1645
1646         return len;
1647 }
1648
1649 ssize_t core_alua_store_tg_pt_gp_info(
1650         struct se_port *port,
1651         const char *page,
1652         size_t count)
1653 {
1654         struct se_portal_group *tpg;
1655         struct se_lun *lun;
1656         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1657         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1658         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1659         unsigned char buf[TG_PT_GROUP_NAME_BUF];
1660         int move = 0;
1661
1662         tpg = port->sep_tpg;
1663         lun = port->sep_lun;
1664
1665         if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
1666                 pr_warn("SPC3_ALUA_EMULATED not enabled for"
1667                         " %s/tpgt_%hu/%s\n", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1668                         tpg->se_tpg_tfo->tpg_get_tag(tpg),
1669                         config_item_name(&lun->lun_group.cg_item));
1670                 return -EINVAL;
1671         }
1672
1673         if (count > TG_PT_GROUP_NAME_BUF) {
1674                 pr_err("ALUA Target Port Group alias too large!\n");
1675                 return -EINVAL;
1676         }
1677         memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1678         memcpy(buf, page, count);
1679         /*
1680          * Any ALUA target port group alias besides "NULL" means we will be
1681          * making a new group association.
1682          */
1683         if (strcmp(strstrip(buf), "NULL")) {
1684                 /*
1685                  * core_alua_get_tg_pt_gp_by_name() will increment reference to
1686                  * struct t10_alua_tg_pt_gp.  This reference is released with
1687                  * core_alua_put_tg_pt_gp_from_name() below.
1688                  */
1689                 tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(su_dev,
1690                                         strstrip(buf));
1691                 if (!tg_pt_gp_new)
1692                         return -ENODEV;
1693         }
1694         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1695         if (!tg_pt_gp_mem) {
1696                 if (tg_pt_gp_new)
1697                         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1698                 pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
1699                 return -EINVAL;
1700         }
1701
1702         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1703         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1704         if (tg_pt_gp) {
1705                 /*
1706                  * Clearing an existing tg_pt_gp association, and replacing
1707                  * with the default_tg_pt_gp.
1708                  */
1709                 if (!tg_pt_gp_new) {
1710                         pr_debug("Target_Core_ConfigFS: Moving"
1711                                 " %s/tpgt_%hu/%s from ALUA Target Port Group:"
1712                                 " alua/%s, ID: %hu back to"
1713                                 " default_tg_pt_gp\n",
1714                                 tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1715                                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1716                                 config_item_name(&lun->lun_group.cg_item),
1717                                 config_item_name(
1718                                         &tg_pt_gp->tg_pt_gp_group.cg_item),
1719                                 tg_pt_gp->tg_pt_gp_id);
1720
1721                         __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1722                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1723                                         su_dev->t10_alua.default_tg_pt_gp);
1724                         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1725
1726                         return count;
1727                 }
1728                 /*
1729                  * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1730                  */
1731                 __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1732                 move = 1;
1733         }
1734         /*
1735          * Associate tg_pt_gp_mem with tg_pt_gp_new.
1736          */
1737         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1738         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1739         pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1740                 " Target Port Group: alua/%s, ID: %hu\n", (move) ?
1741                 "Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1742                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1743                 config_item_name(&lun->lun_group.cg_item),
1744                 config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1745                 tg_pt_gp_new->tg_pt_gp_id);
1746
1747         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1748         return count;
1749 }
1750
1751 ssize_t core_alua_show_access_type(
1752         struct t10_alua_tg_pt_gp *tg_pt_gp,
1753         char *page)
1754 {
1755         if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1756             (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1757                 return sprintf(page, "Implict and Explict\n");
1758         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1759                 return sprintf(page, "Implict\n");
1760         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1761                 return sprintf(page, "Explict\n");
1762         else
1763                 return sprintf(page, "None\n");
1764 }
1765
1766 ssize_t core_alua_store_access_type(
1767         struct t10_alua_tg_pt_gp *tg_pt_gp,
1768         const char *page,
1769         size_t count)
1770 {
1771         unsigned long tmp;
1772         int ret;
1773
1774         ret = strict_strtoul(page, 0, &tmp);
1775         if (ret < 0) {
1776                 pr_err("Unable to extract alua_access_type\n");
1777                 return -EINVAL;
1778         }
1779         if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1780                 pr_err("Illegal value for alua_access_type:"
1781                                 " %lu\n", tmp);
1782                 return -EINVAL;
1783         }
1784         if (tmp == 3)
1785                 tg_pt_gp->tg_pt_gp_alua_access_type =
1786                         TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1787         else if (tmp == 2)
1788                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1789         else if (tmp == 1)
1790                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1791         else
1792                 tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1793
1794         return count;
1795 }
1796
1797 ssize_t core_alua_show_nonop_delay_msecs(
1798         struct t10_alua_tg_pt_gp *tg_pt_gp,
1799         char *page)
1800 {
1801         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1802 }
1803
1804 ssize_t core_alua_store_nonop_delay_msecs(
1805         struct t10_alua_tg_pt_gp *tg_pt_gp,
1806         const char *page,
1807         size_t count)
1808 {
1809         unsigned long tmp;
1810         int ret;
1811
1812         ret = strict_strtoul(page, 0, &tmp);
1813         if (ret < 0) {
1814                 pr_err("Unable to extract nonop_delay_msecs\n");
1815                 return -EINVAL;
1816         }
1817         if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1818                 pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1819                         " ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1820                         ALUA_MAX_NONOP_DELAY_MSECS);
1821                 return -EINVAL;
1822         }
1823         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1824
1825         return count;
1826 }
1827
1828 ssize_t core_alua_show_trans_delay_msecs(
1829         struct t10_alua_tg_pt_gp *tg_pt_gp,
1830         char *page)
1831 {
1832         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1833 }
1834
1835 ssize_t core_alua_store_trans_delay_msecs(
1836         struct t10_alua_tg_pt_gp *tg_pt_gp,
1837         const char *page,
1838         size_t count)
1839 {
1840         unsigned long tmp;
1841         int ret;
1842
1843         ret = strict_strtoul(page, 0, &tmp);
1844         if (ret < 0) {
1845                 pr_err("Unable to extract trans_delay_msecs\n");
1846                 return -EINVAL;
1847         }
1848         if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1849                 pr_err("Passed trans_delay_msecs: %lu, exceeds"
1850                         " ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1851                         ALUA_MAX_TRANS_DELAY_MSECS);
1852                 return -EINVAL;
1853         }
1854         tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1855
1856         return count;
1857 }
1858
1859 ssize_t core_alua_show_preferred_bit(
1860         struct t10_alua_tg_pt_gp *tg_pt_gp,
1861         char *page)
1862 {
1863         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1864 }
1865
1866 ssize_t core_alua_store_preferred_bit(
1867         struct t10_alua_tg_pt_gp *tg_pt_gp,
1868         const char *page,
1869         size_t count)
1870 {
1871         unsigned long tmp;
1872         int ret;
1873
1874         ret = strict_strtoul(page, 0, &tmp);
1875         if (ret < 0) {
1876                 pr_err("Unable to extract preferred ALUA value\n");
1877                 return -EINVAL;
1878         }
1879         if ((tmp != 0) && (tmp != 1)) {
1880                 pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1881                 return -EINVAL;
1882         }
1883         tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1884
1885         return count;
1886 }
1887
1888 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1889 {
1890         if (!lun->lun_sep)
1891                 return -ENODEV;
1892
1893         return sprintf(page, "%d\n",
1894                 atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1895 }
1896
1897 ssize_t core_alua_store_offline_bit(
1898         struct se_lun *lun,
1899         const char *page,
1900         size_t count)
1901 {
1902         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1903         unsigned long tmp;
1904         int ret;
1905
1906         if (!lun->lun_sep)
1907                 return -ENODEV;
1908
1909         ret = strict_strtoul(page, 0, &tmp);
1910         if (ret < 0) {
1911                 pr_err("Unable to extract alua_tg_pt_offline value\n");
1912                 return -EINVAL;
1913         }
1914         if ((tmp != 0) && (tmp != 1)) {
1915                 pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1916                                 tmp);
1917                 return -EINVAL;
1918         }
1919         tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1920         if (!tg_pt_gp_mem) {
1921                 pr_err("Unable to locate *tg_pt_gp_mem\n");
1922                 return -EINVAL;
1923         }
1924
1925         ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1926                         lun->lun_sep, 0, (int)tmp);
1927         if (ret < 0)
1928                 return -EINVAL;
1929
1930         return count;
1931 }
1932
1933 ssize_t core_alua_show_secondary_status(
1934         struct se_lun *lun,
1935         char *page)
1936 {
1937         return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1938 }
1939
1940 ssize_t core_alua_store_secondary_status(
1941         struct se_lun *lun,
1942         const char *page,
1943         size_t count)
1944 {
1945         unsigned long tmp;
1946         int ret;
1947
1948         ret = strict_strtoul(page, 0, &tmp);
1949         if (ret < 0) {
1950                 pr_err("Unable to extract alua_tg_pt_status\n");
1951                 return -EINVAL;
1952         }
1953         if ((tmp != ALUA_STATUS_NONE) &&
1954             (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
1955             (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
1956                 pr_err("Illegal value for alua_tg_pt_status: %lu\n",
1957                                 tmp);
1958                 return -EINVAL;
1959         }
1960         lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
1961
1962         return count;
1963 }
1964
1965 ssize_t core_alua_show_secondary_write_metadata(
1966         struct se_lun *lun,
1967         char *page)
1968 {
1969         return sprintf(page, "%d\n",
1970                         lun->lun_sep->sep_tg_pt_secondary_write_md);
1971 }
1972
1973 ssize_t core_alua_store_secondary_write_metadata(
1974         struct se_lun *lun,
1975         const char *page,
1976         size_t count)
1977 {
1978         unsigned long tmp;
1979         int ret;
1980
1981         ret = strict_strtoul(page, 0, &tmp);
1982         if (ret < 0) {
1983                 pr_err("Unable to extract alua_tg_pt_write_md\n");
1984                 return -EINVAL;
1985         }
1986         if ((tmp != 0) && (tmp != 1)) {
1987                 pr_err("Illegal value for alua_tg_pt_write_md:"
1988                                 " %lu\n", tmp);
1989                 return -EINVAL;
1990         }
1991         lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
1992
1993         return count;
1994 }
1995
1996 int core_setup_alua(struct se_device *dev, int force_pt)
1997 {
1998         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1999         struct t10_alua *alua = &su_dev->t10_alua;
2000         struct t10_alua_lu_gp_member *lu_gp_mem;
2001         /*
2002          * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
2003          * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
2004          * cause a problem because libata and some SATA RAID HBAs appear
2005          * under Linux/SCSI, but emulate SCSI logic themselves.
2006          */
2007         if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
2008             !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
2009                 alua->alua_type = SPC_ALUA_PASSTHROUGH;
2010                 alua->alua_state_check = &core_alua_state_check_nop;
2011                 pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
2012                         " emulation\n", dev->transport->name);
2013                 return 0;
2014         }
2015         /*
2016          * If SPC-3 or above is reported by real or emulated struct se_device,
2017          * use emulated ALUA.
2018          */
2019         if (dev->transport->get_device_rev(dev) >= SCSI_3) {
2020                 pr_debug("%s: Enabling ALUA Emulation for SPC-3"
2021                         " device\n", dev->transport->name);
2022                 /*
2023                  * Associate this struct se_device with the default ALUA
2024                  * LUN Group.
2025                  */
2026                 lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2027                 if (IS_ERR(lu_gp_mem))
2028                         return PTR_ERR(lu_gp_mem);
2029
2030                 alua->alua_type = SPC3_ALUA_EMULATED;
2031                 alua->alua_state_check = &core_alua_state_check;
2032                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2033                 __core_alua_attach_lu_gp_mem(lu_gp_mem,
2034                                 default_lu_gp);
2035                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2036
2037                 pr_debug("%s: Adding to default ALUA LU Group:"
2038                         " core/alua/lu_gps/default_lu_gp\n",
2039                         dev->transport->name);
2040         } else {
2041                 alua->alua_type = SPC2_ALUA_DISABLED;
2042                 alua->alua_state_check = &core_alua_state_check_nop;
2043                 pr_debug("%s: Disabling ALUA Emulation for SPC-2"
2044                         " device\n", dev->transport->name);
2045         }
2046
2047         return 0;
2048 }