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         if (!rc) {
 356                 task->task_scsi_status = GOOD;
 357                 transport_complete_task(task, 1);
 358         }
 359         return rc;
 360 }
 361
 362 static inline int core_alua_state_nonoptimized(
 363         struct se_cmd *cmd,
 364         unsigned char *cdb,
 365         int nonop_delay_msecs,
 366         u8 *alua_ascq)
 367 {
 368         /*
 369          * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
 370          * later to determine if processing of this cmd needs to be
 371          * temporarily delayed for the Active/NonOptimized primary access state.
 372          */
 373         cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
 374         cmd->alua_nonop_delay = nonop_delay_msecs;
 375         return 0;
 376 }
 377
 378 static inline int core_alua_state_standby(
 379         struct se_cmd *cmd,
 380         unsigned char *cdb,
 381         u8 *alua_ascq)
 382 {
 383         /*
 384          * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
 385          * spc4r17 section 5.9.2.4.4
 386          */
 387         switch (cdb[0]) {
 388         case INQUIRY:
 389         case LOG_SELECT:
 390         case LOG_SENSE:
 391         case MODE_SELECT:
 392         case MODE_SENSE:
 393         case REPORT_LUNS:
 394         case RECEIVE_DIAGNOSTIC:
 395         case SEND_DIAGNOSTIC:
 396                 return 0;
 397         case MAINTENANCE_IN:
 398                 switch (cdb[1] & 0x1f) {
 399                 case MI_REPORT_TARGET_PGS:
 400                         return 0;
 401                 default:
 402                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 403                         return 1;
 404                 }
 405         case MAINTENANCE_OUT:
 406                 switch (cdb[1]) {
 407                 case MO_SET_TARGET_PGS:
 408                         return 0;
 409                 default:
 410                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 411                         return 1;
 412                 }
 413         case REQUEST_SENSE:
 414         case PERSISTENT_RESERVE_IN:
 415         case PERSISTENT_RESERVE_OUT:
 416         case READ_BUFFER:
 417         case WRITE_BUFFER:
 418                 return 0;
 419         default:
 420                 *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 421                 return 1;
 422         }
 423
 424         return 0;
 425 }
 426
 427 static inline int core_alua_state_unavailable(
 428         struct se_cmd *cmd,
 429         unsigned char *cdb,
 430         u8 *alua_ascq)
 431 {
 432         /*
 433          * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
 434          * spc4r17 section 5.9.2.4.5
 435          */
 436         switch (cdb[0]) {
 437         case INQUIRY:
 438         case REPORT_LUNS:
 439                 return 0;
 440         case MAINTENANCE_IN:
 441                 switch (cdb[1] & 0x1f) {
 442                 case MI_REPORT_TARGET_PGS:
 443                         return 0;
 444                 default:
 445                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 446                         return 1;
 447                 }
 448         case MAINTENANCE_OUT:
 449                 switch (cdb[1]) {
 450                 case MO_SET_TARGET_PGS:
 451                         return 0;
 452                 default:
 453                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 454                         return 1;
 455                 }
 456         case REQUEST_SENSE:
 457         case READ_BUFFER:
 458         case WRITE_BUFFER:
 459                 return 0;
 460         default:
 461                 *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 462                 return 1;
 463         }
 464
 465         return 0;
 466 }
 467
 468 static inline int core_alua_state_transition(
 469         struct se_cmd *cmd,
 470         unsigned char *cdb,
 471         u8 *alua_ascq)
 472 {
 473         /*
 474          * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
 475          * spc4r17 section 5.9.2.5
 476          */
 477         switch (cdb[0]) {
 478         case INQUIRY:
 479         case REPORT_LUNS:
 480                 return 0;
 481         case MAINTENANCE_IN:
 482                 switch (cdb[1] & 0x1f) {
 483                 case MI_REPORT_TARGET_PGS:
 484                         return 0;
 485                 default:
 486                         *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 487                         return 1;
 488                 }
 489         case REQUEST_SENSE:
 490         case READ_BUFFER:
 491         case WRITE_BUFFER:
 492                 return 0;
 493         default:
 494                 *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 495                 return 1;
 496         }
 497
 498         return 0;
 499 }
 500
 501 /*
 502  * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
 503  * in transport_cmd_sequencer().  This function is assigned to
 504  * struct t10_alua *->state_check() in core_setup_alua()
 505  */
 506 static int core_alua_state_check_nop(
 507         struct se_cmd *cmd,
 508         unsigned char *cdb,
 509         u8 *alua_ascq)
 510 {
 511         return 0;
 512 }
 513
 514 /*
 515  * Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
 516  * This function is assigned to struct t10_alua *->state_check() in
 517  * core_setup_alua()
 518  *
 519  * Also, this function can return three different return codes to
 520  * signal transport_generic_cmd_sequencer()
 521  *
 522  * return 1: Is used to signal LUN not accecsable, and check condition/not ready
 523  * return 0: Used to signal success
 524  * reutrn -1: Used to signal failure, and invalid cdb field
 525  */
 526 static int core_alua_state_check(
 527         struct se_cmd *cmd,
 528         unsigned char *cdb,
 529         u8 *alua_ascq)
 530 {
 531         struct se_lun *lun = cmd->se_lun;
 532         struct se_port *port = lun->lun_sep;
 533         struct t10_alua_tg_pt_gp *tg_pt_gp;
 534         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
 535         int out_alua_state, nonop_delay_msecs;
 536
 537         if (!port)
 538                 return 0;
 539         /*
 540          * First, check for a struct se_port specific secondary ALUA target port
 541          * access state: OFFLINE
 542          */
 543         if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
 544                 *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 545                 pr_debug("ALUA: Got secondary offline status for local"
 546                                 " target port\n");
 547                 *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 548                 return 1;
 549         }
 550          /*
 551          * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
 552          * ALUA target port group, to obtain current ALUA access state.
 553          * Otherwise look for the underlying struct se_device association with
 554          * a ALUA logical unit group.
 555          */
 556         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 557         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 558         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
 559         out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 560         nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
 561         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 562         /*
 563          * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a separate conditional
 564          * statement so the compiler knows explicitly to check this case first.
 565          * For the Optimized ALUA access state case, we want to process the
 566          * incoming fabric cmd ASAP..
 567          */
 568         if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
 569                 return 0;
 570
 571         switch (out_alua_state) {
 572         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 573                 return core_alua_state_nonoptimized(cmd, cdb,
 574                                         nonop_delay_msecs, alua_ascq);
 575         case ALUA_ACCESS_STATE_STANDBY:
 576                 return core_alua_state_standby(cmd, cdb, alua_ascq);
 577         case ALUA_ACCESS_STATE_UNAVAILABLE:
 578                 return core_alua_state_unavailable(cmd, cdb, alua_ascq);
 579         case ALUA_ACCESS_STATE_TRANSITION:
 580                 return core_alua_state_transition(cmd, cdb, alua_ascq);
 581         /*
 582          * OFFLINE is a secondary ALUA target port group access state, that is
 583          * handled above with struct se_port->sep_tg_pt_secondary_offline=1
 584          */
 585         case ALUA_ACCESS_STATE_OFFLINE:
 586         default:
 587                 pr_err("Unknown ALUA access state: 0x%02x\n",
 588                                 out_alua_state);
 589                 return -EINVAL;
 590         }
 591
 592         return 0;
 593 }
 594
 595 /*
 596  * Check implict and explict ALUA state change request.
 597  */
 598 static int core_alua_check_transition(int state, int *primary)
 599 {
 600         switch (state) {
 601         case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 602         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 603         case ALUA_ACCESS_STATE_STANDBY:
 604         case ALUA_ACCESS_STATE_UNAVAILABLE:
 605                 /*
 606                  * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
 607                  * defined as primary target port asymmetric access states.
 608                  */
 609                 *primary = 1;
 610                 break;
 611         case ALUA_ACCESS_STATE_OFFLINE:
 612                 /*
 613                  * OFFLINE state is defined as a secondary target port
 614                  * asymmetric access state.
 615                  */
 616                 *primary = 0;
 617                 break;
 618         default:
 619                 pr_err("Unknown ALUA access state: 0x%02x\n", state);
 620                 return -EINVAL;
 621         }
 622
 623         return 0;
 624 }
 625
 626 static char *core_alua_dump_state(int state)
 627 {
 628         switch (state) {
 629         case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 630                 return "Active/Optimized";
 631         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 632                 return "Active/NonOptimized";
 633         case ALUA_ACCESS_STATE_STANDBY:
 634                 return "Standby";
 635         case ALUA_ACCESS_STATE_UNAVAILABLE:
 636                 return "Unavailable";
 637         case ALUA_ACCESS_STATE_OFFLINE:
 638                 return "Offline";
 639         default:
 640                 return "Unknown";
 641         }
 642
 643         return NULL;
 644 }
 645
 646 char *core_alua_dump_status(int status)
 647 {
 648         switch (status) {
 649         case ALUA_STATUS_NONE:
 650                 return "None";
 651         case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
 652                 return "Altered by Explict STPG";
 653         case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
 654                 return "Altered by Implict ALUA";
 655         default:
 656                 return "Unknown";
 657         }
 658
 659         return NULL;
 660 }
 661
 662 /*
 663  * Used by fabric modules to determine when we need to delay processing
 664  * for the Active/NonOptimized paths..
 665  */
 666 int core_alua_check_nonop_delay(
 667         struct se_cmd *cmd)
 668 {
 669         if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
 670                 return 0;
 671         if (in_interrupt())
 672                 return 0;
 673         /*
 674          * The ALUA Active/NonOptimized access state delay can be disabled
 675          * in via configfs with a value of zero
 676          */
 677         if (!cmd->alua_nonop_delay)
 678                 return 0;
 679         /*
 680          * struct se_cmd->alua_nonop_delay gets set by a target port group
 681          * defined interval in core_alua_state_nonoptimized()
 682          */
 683         msleep_interruptible(cmd->alua_nonop_delay);
 684         return 0;
 685 }
 686 EXPORT_SYMBOL(core_alua_check_nonop_delay);
 687
 688 /*
 689  * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
 690  *
 691  */
 692 static int core_alua_write_tpg_metadata(
 693         const char *path,
 694         unsigned char *md_buf,
 695         u32 md_buf_len)
 696 {
 697         mm_segment_t old_fs;
 698         struct file *file;
 699         struct iovec iov[1];
 700         int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
 701
 702         memset(iov, 0, sizeof(struct iovec));
 703
 704         file = filp_open(path, flags, 0600);
 705         if (IS_ERR(file) || !file || !file->f_dentry) {
 706                 pr_err("filp_open(%s) for ALUA metadata failed\n",
 707                         path);
 708                 return -ENODEV;
 709         }
 710
 711         iov[0].iov_base = &md_buf[0];
 712         iov[0].iov_len = md_buf_len;
 713
 714         old_fs = get_fs();
 715         set_fs(get_ds());
 716         ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
 717         set_fs(old_fs);
 718
 719         if (ret < 0) {
 720                 pr_err("Error writing ALUA metadata file: %s\n", path);
 721                 filp_close(file, NULL);
 722                 return -EIO;
 723         }
 724         filp_close(file, NULL);
 725
 726         return 0;
 727 }
 728
 729 /*
 730  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
 731  */
 732 static int core_alua_update_tpg_primary_metadata(
 733         struct t10_alua_tg_pt_gp *tg_pt_gp,
 734         int primary_state,
 735         unsigned char *md_buf)
 736 {
 737         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
 738         struct t10_wwn *wwn = &su_dev->t10_wwn;
 739         char path[ALUA_METADATA_PATH_LEN];
 740         int len;
 741
 742         memset(path, 0, ALUA_METADATA_PATH_LEN);
 743
 744         len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
 745                         "tg_pt_gp_id=%hu\n"
 746                         "alua_access_state=0x%02x\n"
 747                         "alua_access_status=0x%02x\n",
 748                         tg_pt_gp->tg_pt_gp_id, primary_state,
 749                         tg_pt_gp->tg_pt_gp_alua_access_status);
 750
 751         snprintf(path, ALUA_METADATA_PATH_LEN,
 752                 "/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
 753                 config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 754
 755         return core_alua_write_tpg_metadata(path, md_buf, len);
 756 }
 757
 758 static int core_alua_do_transition_tg_pt(
 759         struct t10_alua_tg_pt_gp *tg_pt_gp,
 760         struct se_port *l_port,
 761         struct se_node_acl *nacl,
 762         unsigned char *md_buf,
 763         int new_state,
 764         int explict)
 765 {
 766         struct se_dev_entry *se_deve;
 767         struct se_lun_acl *lacl;
 768         struct se_port *port;
 769         struct t10_alua_tg_pt_gp_member *mem;
 770         int old_state = 0;
 771         /*
 772          * Save the old primary ALUA access state, and set the current state
 773          * to ALUA_ACCESS_STATE_TRANSITION.
 774          */
 775         old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 776         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
 777                         ALUA_ACCESS_STATE_TRANSITION);
 778         tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
 779                                 ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
 780                                 ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
 781         /*
 782          * Check for the optional ALUA primary state transition delay
 783          */
 784         if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
 785                 msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
 786
 787         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 788         list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
 789                                 tg_pt_gp_mem_list) {
 790                 port = mem->tg_pt;
 791                 /*
 792                  * After an implicit target port asymmetric access state
 793                  * change, a device server shall establish a unit attention
 794                  * condition for the initiator port associated with every I_T
 795                  * nexus with the additional sense code set to ASYMMETRIC
 796                  * ACCESS STATE CHAGED.
 797                  *
 798                  * After an explicit target port asymmetric access state
 799                  * change, a device server shall establish a unit attention
 800                  * condition with the additional sense code set to ASYMMETRIC
 801                  * ACCESS STATE CHANGED for the initiator port associated with
 802                  * every I_T nexus other than the I_T nexus on which the SET
 803                  * TARGET PORT GROUPS command
 804                  */
 805                 atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
 806                 smp_mb__after_atomic_inc();
 807                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 808
 809                 spin_lock_bh(&port->sep_alua_lock);
 810                 list_for_each_entry(se_deve, &port->sep_alua_list,
 811                                         alua_port_list) {
 812                         lacl = se_deve->se_lun_acl;
 813                         /*
 814                          * se_deve->se_lun_acl pointer may be NULL for a
 815                          * entry created without explict Node+MappedLUN ACLs
 816                          */
 817                         if (!lacl)
 818                                 continue;
 819
 820                         if (explict &&
 821                            (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
 822                            (l_port != NULL) && (l_port == port))
 823                                 continue;
 824
 825                         core_scsi3_ua_allocate(lacl->se_lun_nacl,
 826                                 se_deve->mapped_lun, 0x2A,
 827                                 ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
 828                 }
 829                 spin_unlock_bh(&port->sep_alua_lock);
 830
 831                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 832                 atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
 833                 smp_mb__after_atomic_dec();
 834         }
 835         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 836         /*
 837          * Update the ALUA metadata buf that has been allocated in
 838          * core_alua_do_port_transition(), this metadata will be written
 839          * to struct file.
 840          *
 841          * Note that there is the case where we do not want to update the
 842          * metadata when the saved metadata is being parsed in userspace
 843          * when setting the existing port access state and access status.
 844          *
 845          * Also note that the failure to write out the ALUA metadata to
 846          * struct file does NOT affect the actual ALUA transition.
 847          */
 848         if (tg_pt_gp->tg_pt_gp_write_metadata) {
 849                 mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
 850                 core_alua_update_tpg_primary_metadata(tg_pt_gp,
 851                                         new_state, md_buf);
 852                 mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
 853         }
 854         /*
 855          * Set the current primary ALUA access state to the requested new state
 856          */
 857         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
 858
 859         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
 860                 " from primary access state %s to %s\n", (explict) ? "explict" :
 861                 "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
 862                 tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
 863                 core_alua_dump_state(new_state));
 864
 865         return 0;
 866 }
 867
 868 int core_alua_do_port_transition(
 869         struct t10_alua_tg_pt_gp *l_tg_pt_gp,
 870         struct se_device *l_dev,
 871         struct se_port *l_port,
 872         struct se_node_acl *l_nacl,
 873         int new_state,
 874         int explict)
 875 {
 876         struct se_device *dev;
 877         struct se_port *port;
 878         struct se_subsystem_dev *su_dev;
 879         struct se_node_acl *nacl;
 880         struct t10_alua_lu_gp *lu_gp;
 881         struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
 882         struct t10_alua_tg_pt_gp *tg_pt_gp;
 883         unsigned char *md_buf;
 884         int primary;
 885
 886         if (core_alua_check_transition(new_state, &primary) != 0)
 887                 return -EINVAL;
 888
 889         md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
 890         if (!md_buf) {
 891                 pr_err("Unable to allocate buf for ALUA metadata\n");
 892                 return -ENOMEM;
 893         }
 894
 895         local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
 896         spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
 897         lu_gp = local_lu_gp_mem->lu_gp;
 898         atomic_inc(&lu_gp->lu_gp_ref_cnt);
 899         smp_mb__after_atomic_inc();
 900         spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
 901         /*
 902          * For storage objects that are members of the 'default_lu_gp',
 903          * we only do transition on the passed *l_tp_pt_gp, and not
 904          * on all of the matching target port groups IDs in default_lu_gp.
 905          */
 906         if (!lu_gp->lu_gp_id) {
 907                 /*
 908                  * core_alua_do_transition_tg_pt() will always return
 909                  * success.
 910                  */
 911                 core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
 912                                         md_buf, new_state, explict);
 913                 atomic_dec(&lu_gp->lu_gp_ref_cnt);
 914                 smp_mb__after_atomic_dec();
 915                 kfree(md_buf);
 916                 return 0;
 917         }
 918         /*
 919          * For all other LU groups aside from 'default_lu_gp', walk all of
 920          * the associated storage objects looking for a matching target port
 921          * group ID from the local target port group.
 922          */
 923         spin_lock(&lu_gp->lu_gp_lock);
 924         list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
 925                                 lu_gp_mem_list) {
 926
 927                 dev = lu_gp_mem->lu_gp_mem_dev;
 928                 su_dev = dev->se_sub_dev;
 929                 atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
 930                 smp_mb__after_atomic_inc();
 931                 spin_unlock(&lu_gp->lu_gp_lock);
 932
 933                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 934                 list_for_each_entry(tg_pt_gp,
 935                                 &su_dev->t10_alua.tg_pt_gps_list,
 936                                 tg_pt_gp_list) {
 937
 938                         if (!tg_pt_gp->tg_pt_gp_valid_id)
 939                                 continue;
 940                         /*
 941                          * If the target behavior port asymmetric access state
 942                          * is changed for any target port group accessiable via
 943                          * a logical unit within a LU group, the target port
 944                          * behavior group asymmetric access states for the same
 945                          * target port group accessible via other logical units
 946                          * in that LU group will also change.
 947                          */
 948                         if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
 949                                 continue;
 950
 951                         if (l_tg_pt_gp == tg_pt_gp) {
 952                                 port = l_port;
 953                                 nacl = l_nacl;
 954                         } else {
 955                                 port = NULL;
 956                                 nacl = NULL;
 957                         }
 958                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 959                         smp_mb__after_atomic_inc();
 960                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 961                         /*
 962                          * core_alua_do_transition_tg_pt() will always return
 963                          * success.
 964                          */
 965                         core_alua_do_transition_tg_pt(tg_pt_gp, port,
 966                                         nacl, md_buf, new_state, explict);
 967
 968                         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 969                         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
 970                         smp_mb__after_atomic_dec();
 971                 }
 972                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 973
 974                 spin_lock(&lu_gp->lu_gp_lock);
 975                 atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
 976                 smp_mb__after_atomic_dec();
 977         }
 978         spin_unlock(&lu_gp->lu_gp_lock);
 979
 980         pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
 981                 " Group IDs: %hu %s transition to primary state: %s\n",
 982                 config_item_name(&lu_gp->lu_gp_group.cg_item),
 983                 l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
 984                 core_alua_dump_state(new_state));
 985
 986         atomic_dec(&lu_gp->lu_gp_ref_cnt);
 987         smp_mb__after_atomic_dec();
 988         kfree(md_buf);
 989         return 0;
 990 }
 991
 992 /*
 993  * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
 994  */
 995 static int core_alua_update_tpg_secondary_metadata(
 996         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
 997         struct se_port *port,
 998         unsigned char *md_buf,
 999         u32 md_buf_len)
1000 {
1001         struct se_portal_group *se_tpg = port->sep_tpg;
1002         char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
1003         int len;
1004
1005         memset(path, 0, ALUA_METADATA_PATH_LEN);
1006         memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1007
1008         len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1009                         se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1010
1011         if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1012                 snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1013                                 se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1014
1015         len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1016                         "alua_tg_pt_status=0x%02x\n",
1017                         atomic_read(&port->sep_tg_pt_secondary_offline),
1018                         port->sep_tg_pt_secondary_stat);
1019
1020         snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1021                         se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1022                         port->sep_lun->unpacked_lun);
1023
1024         return core_alua_write_tpg_metadata(path, md_buf, len);
1025 }
1026
1027 static int core_alua_set_tg_pt_secondary_state(
1028         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1029         struct se_port *port,
1030         int explict,
1031         int offline)
1032 {
1033         struct t10_alua_tg_pt_gp *tg_pt_gp;
1034         unsigned char *md_buf;
1035         u32 md_buf_len;
1036         int trans_delay_msecs;
1037
1038         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1039         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1040         if (!tg_pt_gp) {
1041                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1042                 pr_err("Unable to complete secondary state"
1043                                 " transition\n");
1044                 return -EINVAL;
1045         }
1046         trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1047         /*
1048          * Set the secondary ALUA target port access state to OFFLINE
1049          * or release the previously secondary state for struct se_port
1050          */
1051         if (offline)
1052                 atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1053         else
1054                 atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1055
1056         md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1057         port->sep_tg_pt_secondary_stat = (explict) ?
1058                         ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
1059                         ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
1060
1061         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1062                 " to secondary access state: %s\n", (explict) ? "explict" :
1063                 "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1064                 tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1065
1066         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1067         /*
1068          * Do the optional transition delay after we set the secondary
1069          * ALUA access state.
1070          */
1071         if (trans_delay_msecs != 0)
1072                 msleep_interruptible(trans_delay_msecs);
1073         /*
1074          * See if we need to update the ALUA fabric port metadata for
1075          * secondary state and status
1076          */
1077         if (port->sep_tg_pt_secondary_write_md) {
1078                 md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1079                 if (!md_buf) {
1080                         pr_err("Unable to allocate md_buf for"
1081                                 " secondary ALUA access metadata\n");
1082                         return -ENOMEM;
1083                 }
1084                 mutex_lock(&port->sep_tg_pt_md_mutex);
1085                 core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1086                                 md_buf, md_buf_len);
1087                 mutex_unlock(&port->sep_tg_pt_md_mutex);
1088
1089                 kfree(md_buf);
1090         }
1091
1092         return 0;
1093 }
1094
1095 struct t10_alua_lu_gp *
1096 core_alua_allocate_lu_gp(const char *name, int def_group)
1097 {
1098         struct t10_alua_lu_gp *lu_gp;
1099
1100         lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1101         if (!lu_gp) {
1102                 pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1103                 return ERR_PTR(-ENOMEM);
1104         }
1105         INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1106         INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1107         spin_lock_init(&lu_gp->lu_gp_lock);
1108         atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1109
1110         if (def_group) {
1111                 lu_gp->lu_gp_id = alua_lu_gps_counter++;
1112                 lu_gp->lu_gp_valid_id = 1;
1113                 alua_lu_gps_count++;
1114         }
1115
1116         return lu_gp;
1117 }
1118
1119 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1120 {
1121         struct t10_alua_lu_gp *lu_gp_tmp;
1122         u16 lu_gp_id_tmp;
1123         /*
1124          * The lu_gp->lu_gp_id may only be set once..
1125          */
1126         if (lu_gp->lu_gp_valid_id) {
1127                 pr_warn("ALUA LU Group already has a valid ID,"
1128                         " ignoring request\n");
1129                 return -EINVAL;
1130         }
1131
1132         spin_lock(&lu_gps_lock);
1133         if (alua_lu_gps_count == 0x0000ffff) {
1134                 pr_err("Maximum ALUA alua_lu_gps_count:"
1135                                 " 0x0000ffff reached\n");
1136                 spin_unlock(&lu_gps_lock);
1137                 kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1138                 return -ENOSPC;
1139         }
1140 again:
1141         lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1142                                 alua_lu_gps_counter++;
1143
1144         list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1145                 if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1146                         if (!lu_gp_id)
1147                                 goto again;
1148
1149                         pr_warn("ALUA Logical Unit Group ID: %hu"
1150                                 " already exists, ignoring request\n",
1151                                 lu_gp_id);
1152                         spin_unlock(&lu_gps_lock);
1153                         return -EINVAL;
1154                 }
1155         }
1156
1157         lu_gp->lu_gp_id = lu_gp_id_tmp;
1158         lu_gp->lu_gp_valid_id = 1;
1159         list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1160         alua_lu_gps_count++;
1161         spin_unlock(&lu_gps_lock);
1162
1163         return 0;
1164 }
1165
1166 static struct t10_alua_lu_gp_member *
1167 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1168 {
1169         struct t10_alua_lu_gp_member *lu_gp_mem;
1170
1171         lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1172         if (!lu_gp_mem) {
1173                 pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1174                 return ERR_PTR(-ENOMEM);
1175         }
1176         INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1177         spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1178         atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1179
1180         lu_gp_mem->lu_gp_mem_dev = dev;
1181         dev->dev_alua_lu_gp_mem = lu_gp_mem;
1182
1183         return lu_gp_mem;
1184 }
1185
1186 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1187 {
1188         struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1189         /*
1190          * Once we have reached this point, config_item_put() has
1191          * already been called from target_core_alua_drop_lu_gp().
1192          *
1193          * Here, we remove the *lu_gp from the global list so that
1194          * no associations can be made while we are releasing
1195          * struct t10_alua_lu_gp.
1196          */
1197         spin_lock(&lu_gps_lock);
1198         list_del(&lu_gp->lu_gp_node);
1199         alua_lu_gps_count--;
1200         spin_unlock(&lu_gps_lock);
1201         /*
1202          * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1203          * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1204          * released with core_alua_put_lu_gp_from_name()
1205          */
1206         while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1207                 cpu_relax();
1208         /*
1209          * Release reference to struct t10_alua_lu_gp * from all associated
1210          * struct se_device.
1211          */
1212         spin_lock(&lu_gp->lu_gp_lock);
1213         list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1214                                 &lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1215                 if (lu_gp_mem->lu_gp_assoc) {
1216                         list_del(&lu_gp_mem->lu_gp_mem_list);
1217                         lu_gp->lu_gp_members--;
1218                         lu_gp_mem->lu_gp_assoc = 0;
1219                 }
1220                 spin_unlock(&lu_gp->lu_gp_lock);
1221                 /*
1222                  *
1223                  * lu_gp_mem is associated with a single
1224                  * struct se_device->dev_alua_lu_gp_mem, and is released when
1225                  * struct se_device is released via core_alua_free_lu_gp_mem().
1226                  *
1227                  * If the passed lu_gp does NOT match the default_lu_gp, assume
1228                  * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1229                  */
1230                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1231                 if (lu_gp != default_lu_gp)
1232                         __core_alua_attach_lu_gp_mem(lu_gp_mem,
1233                                         default_lu_gp);
1234                 else
1235                         lu_gp_mem->lu_gp = NULL;
1236                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1237
1238                 spin_lock(&lu_gp->lu_gp_lock);
1239         }
1240         spin_unlock(&lu_gp->lu_gp_lock);
1241
1242         kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1243 }
1244
1245 void core_alua_free_lu_gp_mem(struct se_device *dev)
1246 {
1247         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1248         struct t10_alua *alua = &su_dev->t10_alua;
1249         struct t10_alua_lu_gp *lu_gp;
1250         struct t10_alua_lu_gp_member *lu_gp_mem;
1251
1252         if (alua->alua_type != SPC3_ALUA_EMULATED)
1253                 return;
1254
1255         lu_gp_mem = dev->dev_alua_lu_gp_mem;
1256         if (!lu_gp_mem)
1257                 return;
1258
1259         while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1260                 cpu_relax();
1261
1262         spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1263         lu_gp = lu_gp_mem->lu_gp;
1264         if (lu_gp) {
1265                 spin_lock(&lu_gp->lu_gp_lock);
1266                 if (lu_gp_mem->lu_gp_assoc) {
1267                         list_del(&lu_gp_mem->lu_gp_mem_list);
1268                         lu_gp->lu_gp_members--;
1269                         lu_gp_mem->lu_gp_assoc = 0;
1270                 }
1271                 spin_unlock(&lu_gp->lu_gp_lock);
1272                 lu_gp_mem->lu_gp = NULL;
1273         }
1274         spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1275
1276         kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1277 }
1278
1279 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1280 {
1281         struct t10_alua_lu_gp *lu_gp;
1282         struct config_item *ci;
1283
1284         spin_lock(&lu_gps_lock);
1285         list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1286                 if (!lu_gp->lu_gp_valid_id)
1287                         continue;
1288                 ci = &lu_gp->lu_gp_group.cg_item;
1289                 if (!strcmp(config_item_name(ci), name)) {
1290                         atomic_inc(&lu_gp->lu_gp_ref_cnt);
1291                         spin_unlock(&lu_gps_lock);
1292                         return lu_gp;
1293                 }
1294         }
1295         spin_unlock(&lu_gps_lock);
1296
1297         return NULL;
1298 }
1299
1300 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1301 {
1302         spin_lock(&lu_gps_lock);
1303         atomic_dec(&lu_gp->lu_gp_ref_cnt);
1304         spin_unlock(&lu_gps_lock);
1305 }
1306
1307 /*
1308  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1309  */
1310 void __core_alua_attach_lu_gp_mem(
1311         struct t10_alua_lu_gp_member *lu_gp_mem,
1312         struct t10_alua_lu_gp *lu_gp)
1313 {
1314         spin_lock(&lu_gp->lu_gp_lock);
1315         lu_gp_mem->lu_gp = lu_gp;
1316         lu_gp_mem->lu_gp_assoc = 1;
1317         list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1318         lu_gp->lu_gp_members++;
1319         spin_unlock(&lu_gp->lu_gp_lock);
1320 }
1321
1322 /*
1323  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1324  */
1325 void __core_alua_drop_lu_gp_mem(
1326         struct t10_alua_lu_gp_member *lu_gp_mem,
1327         struct t10_alua_lu_gp *lu_gp)
1328 {
1329         spin_lock(&lu_gp->lu_gp_lock);
1330         list_del(&lu_gp_mem->lu_gp_mem_list);
1331         lu_gp_mem->lu_gp = NULL;
1332         lu_gp_mem->lu_gp_assoc = 0;
1333         lu_gp->lu_gp_members--;
1334         spin_unlock(&lu_gp->lu_gp_lock);
1335 }
1336
1337 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
1338         struct se_subsystem_dev *su_dev,
1339         const char *name,
1340         int def_group)
1341 {
1342         struct t10_alua_tg_pt_gp *tg_pt_gp;
1343
1344         tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1345         if (!tg_pt_gp) {
1346                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1347                 return NULL;
1348         }
1349         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1350         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1351         mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1352         spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1353         atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1354         tg_pt_gp->tg_pt_gp_su_dev = su_dev;
1355         tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1356         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1357                 ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1358         /*
1359          * Enable both explict and implict ALUA support by default
1360          */
1361         tg_pt_gp->tg_pt_gp_alua_access_type =
1362                         TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1363         /*
1364          * Set the default Active/NonOptimized Delay in milliseconds
1365          */
1366         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1367         tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1368
1369         if (def_group) {
1370                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1371                 tg_pt_gp->tg_pt_gp_id =
1372                                 su_dev->t10_alua.alua_tg_pt_gps_counter++;
1373                 tg_pt_gp->tg_pt_gp_valid_id = 1;
1374                 su_dev->t10_alua.alua_tg_pt_gps_count++;
1375                 list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1376                               &su_dev->t10_alua.tg_pt_gps_list);
1377                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1378         }
1379
1380         return tg_pt_gp;
1381 }
1382
1383 int core_alua_set_tg_pt_gp_id(
1384         struct t10_alua_tg_pt_gp *tg_pt_gp,
1385         u16 tg_pt_gp_id)
1386 {
1387         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1388         struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1389         u16 tg_pt_gp_id_tmp;
1390         /*
1391          * The tg_pt_gp->tg_pt_gp_id may only be set once..
1392          */
1393         if (tg_pt_gp->tg_pt_gp_valid_id) {
1394                 pr_warn("ALUA TG PT Group already has a valid ID,"
1395                         " ignoring request\n");
1396                 return -EINVAL;
1397         }
1398
1399         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1400         if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1401                 pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1402                         " 0x0000ffff reached\n");
1403                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1404                 kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1405                 return -ENOSPC;
1406         }
1407 again:
1408         tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1409                         su_dev->t10_alua.alua_tg_pt_gps_counter++;
1410
1411         list_for_each_entry(tg_pt_gp_tmp, &su_dev->t10_alua.tg_pt_gps_list,
1412                         tg_pt_gp_list) {
1413                 if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1414                         if (!tg_pt_gp_id)
1415                                 goto again;
1416
1417                         pr_err("ALUA Target Port Group ID: %hu already"
1418                                 " exists, ignoring request\n", tg_pt_gp_id);
1419                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1420                         return -EINVAL;
1421                 }
1422         }
1423
1424         tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1425         tg_pt_gp->tg_pt_gp_valid_id = 1;
1426         list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1427                         &su_dev->t10_alua.tg_pt_gps_list);
1428         su_dev->t10_alua.alua_tg_pt_gps_count++;
1429         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1430
1431         return 0;
1432 }
1433
1434 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1435         struct se_port *port)
1436 {
1437         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1438
1439         tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1440                                 GFP_KERNEL);
1441         if (!tg_pt_gp_mem) {
1442                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1443                 return ERR_PTR(-ENOMEM);
1444         }
1445         INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1446         spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1447         atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1448
1449         tg_pt_gp_mem->tg_pt = port;
1450         port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1451
1452         return tg_pt_gp_mem;
1453 }
1454
1455 void core_alua_free_tg_pt_gp(
1456         struct t10_alua_tg_pt_gp *tg_pt_gp)
1457 {
1458         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1459         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1460         /*
1461          * Once we have reached this point, config_item_put() has already
1462          * been called from target_core_alua_drop_tg_pt_gp().
1463          *
1464          * Here we remove *tg_pt_gp from the global list so that
1465          * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1466          * can be made while we are releasing struct t10_alua_tg_pt_gp.
1467          */
1468         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1469         list_del(&tg_pt_gp->tg_pt_gp_list);
1470         su_dev->t10_alua.alua_tg_pt_gps_counter--;
1471         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1472         /*
1473          * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1474          * core_alua_get_tg_pt_gp_by_name() in
1475          * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1476          * to be released with core_alua_put_tg_pt_gp_from_name().
1477          */
1478         while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1479                 cpu_relax();
1480         /*
1481          * Release reference to struct t10_alua_tg_pt_gp from all associated
1482          * struct se_port.
1483          */
1484         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1485         list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1486                         &tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1487                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1488                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1489                         tg_pt_gp->tg_pt_gp_members--;
1490                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1491                 }
1492                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1493                 /*
1494                  * tg_pt_gp_mem is associated with a single
1495                  * se_port->sep_alua_tg_pt_gp_mem, and is released via
1496                  * core_alua_free_tg_pt_gp_mem().
1497                  *
1498                  * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1499                  * assume we want to re-assocate a given tg_pt_gp_mem with
1500                  * default_tg_pt_gp.
1501                  */
1502                 spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1503                 if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
1504                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1505                                         su_dev->t10_alua.default_tg_pt_gp);
1506                 } else
1507                         tg_pt_gp_mem->tg_pt_gp = NULL;
1508                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1509
1510                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1511         }
1512         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1513
1514         kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1515 }
1516
1517 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1518 {
1519         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1520         struct t10_alua *alua = &su_dev->t10_alua;
1521         struct t10_alua_tg_pt_gp *tg_pt_gp;
1522         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1523
1524         if (alua->alua_type != SPC3_ALUA_EMULATED)
1525                 return;
1526
1527         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1528         if (!tg_pt_gp_mem)
1529                 return;
1530
1531         while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1532                 cpu_relax();
1533
1534         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1535         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1536         if (tg_pt_gp) {
1537                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1538                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1539                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1540                         tg_pt_gp->tg_pt_gp_members--;
1541                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1542                 }
1543                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1544                 tg_pt_gp_mem->tg_pt_gp = NULL;
1545         }
1546         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1547
1548         kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1549 }
1550
1551 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1552         struct se_subsystem_dev *su_dev,
1553         const char *name)
1554 {
1555         struct t10_alua_tg_pt_gp *tg_pt_gp;
1556         struct config_item *ci;
1557
1558         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1559         list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
1560                         tg_pt_gp_list) {
1561                 if (!tg_pt_gp->tg_pt_gp_valid_id)
1562                         continue;
1563                 ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1564                 if (!strcmp(config_item_name(ci), name)) {
1565                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1566                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1567                         return tg_pt_gp;
1568                 }
1569         }
1570         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1571
1572         return NULL;
1573 }
1574
1575 static void core_alua_put_tg_pt_gp_from_name(
1576         struct t10_alua_tg_pt_gp *tg_pt_gp)
1577 {
1578         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1579
1580         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1581         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1582         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1583 }
1584
1585 /*
1586  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1587  */
1588 void __core_alua_attach_tg_pt_gp_mem(
1589         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1590         struct t10_alua_tg_pt_gp *tg_pt_gp)
1591 {
1592         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1593         tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1594         tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1595         list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1596                         &tg_pt_gp->tg_pt_gp_mem_list);
1597         tg_pt_gp->tg_pt_gp_members++;
1598         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1599 }
1600
1601 /*
1602  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1603  */
1604 static void __core_alua_drop_tg_pt_gp_mem(
1605         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1606         struct t10_alua_tg_pt_gp *tg_pt_gp)
1607 {
1608         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1609         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1610         tg_pt_gp_mem->tg_pt_gp = NULL;
1611         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1612         tg_pt_gp->tg_pt_gp_members--;
1613         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1614 }
1615
1616 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1617 {
1618         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1619         struct config_item *tg_pt_ci;
1620         struct t10_alua *alua = &su_dev->t10_alua;
1621         struct t10_alua_tg_pt_gp *tg_pt_gp;
1622         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1623         ssize_t len = 0;
1624
1625         if (alua->alua_type != SPC3_ALUA_EMULATED)
1626                 return len;
1627
1628         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1629         if (!tg_pt_gp_mem)
1630                 return len;
1631
1632         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1633         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1634         if (tg_pt_gp) {
1635                 tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1636                 len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1637                         " %hu\nTG Port Primary Access State: %s\nTG Port "
1638                         "Primary Access Status: %s\nTG Port Secondary Access"
1639                         " State: %s\nTG Port Secondary Access Status: %s\n",
1640                         config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1641                         core_alua_dump_state(atomic_read(
1642                                         &tg_pt_gp->tg_pt_gp_alua_access_state)),
1643                         core_alua_dump_status(
1644                                 tg_pt_gp->tg_pt_gp_alua_access_status),
1645                         (atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1646                         "Offline" : "None",
1647                         core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1648         }
1649         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1650
1651         return len;
1652 }
1653
1654 ssize_t core_alua_store_tg_pt_gp_info(
1655         struct se_port *port,
1656         const char *page,
1657         size_t count)
1658 {
1659         struct se_portal_group *tpg;
1660         struct se_lun *lun;
1661         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1662         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1663         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1664         unsigned char buf[TG_PT_GROUP_NAME_BUF];
1665         int move = 0;
1666
1667         tpg = port->sep_tpg;
1668         lun = port->sep_lun;
1669
1670         if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
1671                 pr_warn("SPC3_ALUA_EMULATED not enabled for"
1672                         " %s/tpgt_%hu/%s\n", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1673                         tpg->se_tpg_tfo->tpg_get_tag(tpg),
1674                         config_item_name(&lun->lun_group.cg_item));
1675                 return -EINVAL;
1676         }
1677
1678         if (count > TG_PT_GROUP_NAME_BUF) {
1679                 pr_err("ALUA Target Port Group alias too large!\n");
1680                 return -EINVAL;
1681         }
1682         memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1683         memcpy(buf, page, count);
1684         /*
1685          * Any ALUA target port group alias besides "NULL" means we will be
1686          * making a new group association.
1687          */
1688         if (strcmp(strstrip(buf), "NULL")) {
1689                 /*
1690                  * core_alua_get_tg_pt_gp_by_name() will increment reference to
1691                  * struct t10_alua_tg_pt_gp.  This reference is released with
1692                  * core_alua_put_tg_pt_gp_from_name() below.
1693                  */
1694                 tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(su_dev,
1695                                         strstrip(buf));
1696                 if (!tg_pt_gp_new)
1697                         return -ENODEV;
1698         }
1699         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1700         if (!tg_pt_gp_mem) {
1701                 if (tg_pt_gp_new)
1702                         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1703                 pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
1704                 return -EINVAL;
1705         }
1706
1707         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1708         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1709         if (tg_pt_gp) {
1710                 /*
1711                  * Clearing an existing tg_pt_gp association, and replacing
1712                  * with the default_tg_pt_gp.
1713                  */
1714                 if (!tg_pt_gp_new) {
1715                         pr_debug("Target_Core_ConfigFS: Moving"
1716                                 " %s/tpgt_%hu/%s from ALUA Target Port Group:"
1717                                 " alua/%s, ID: %hu back to"
1718                                 " default_tg_pt_gp\n",
1719                                 tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1720                                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1721                                 config_item_name(&lun->lun_group.cg_item),
1722                                 config_item_name(
1723                                         &tg_pt_gp->tg_pt_gp_group.cg_item),
1724                                 tg_pt_gp->tg_pt_gp_id);
1725
1726                         __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1727                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1728                                         su_dev->t10_alua.default_tg_pt_gp);
1729                         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1730
1731                         return count;
1732                 }
1733                 /*
1734                  * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1735                  */
1736                 __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1737                 move = 1;
1738         }
1739         /*
1740          * Associate tg_pt_gp_mem with tg_pt_gp_new.
1741          */
1742         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1743         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1744         pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1745                 " Target Port Group: alua/%s, ID: %hu\n", (move) ?
1746                 "Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1747                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1748                 config_item_name(&lun->lun_group.cg_item),
1749                 config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1750                 tg_pt_gp_new->tg_pt_gp_id);
1751
1752         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1753         return count;
1754 }
1755
1756 ssize_t core_alua_show_access_type(
1757         struct t10_alua_tg_pt_gp *tg_pt_gp,
1758         char *page)
1759 {
1760         if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1761             (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1762                 return sprintf(page, "Implict and Explict\n");
1763         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1764                 return sprintf(page, "Implict\n");
1765         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1766                 return sprintf(page, "Explict\n");
1767         else
1768                 return sprintf(page, "None\n");
1769 }
1770
1771 ssize_t core_alua_store_access_type(
1772         struct t10_alua_tg_pt_gp *tg_pt_gp,
1773         const char *page,
1774         size_t count)
1775 {
1776         unsigned long tmp;
1777         int ret;
1778
1779         ret = strict_strtoul(page, 0, &tmp);
1780         if (ret < 0) {
1781                 pr_err("Unable to extract alua_access_type\n");
1782                 return -EINVAL;
1783         }
1784         if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1785                 pr_err("Illegal value for alua_access_type:"
1786                                 " %lu\n", tmp);
1787                 return -EINVAL;
1788         }
1789         if (tmp == 3)
1790                 tg_pt_gp->tg_pt_gp_alua_access_type =
1791                         TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1792         else if (tmp == 2)
1793                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1794         else if (tmp == 1)
1795                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1796         else
1797                 tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1798
1799         return count;
1800 }
1801
1802 ssize_t core_alua_show_nonop_delay_msecs(
1803         struct t10_alua_tg_pt_gp *tg_pt_gp,
1804         char *page)
1805 {
1806         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1807 }
1808
1809 ssize_t core_alua_store_nonop_delay_msecs(
1810         struct t10_alua_tg_pt_gp *tg_pt_gp,
1811         const char *page,
1812         size_t count)
1813 {
1814         unsigned long tmp;
1815         int ret;
1816
1817         ret = strict_strtoul(page, 0, &tmp);
1818         if (ret < 0) {
1819                 pr_err("Unable to extract nonop_delay_msecs\n");
1820                 return -EINVAL;
1821         }
1822         if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1823                 pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1824                         " ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1825                         ALUA_MAX_NONOP_DELAY_MSECS);
1826                 return -EINVAL;
1827         }
1828         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1829
1830         return count;
1831 }
1832
1833 ssize_t core_alua_show_trans_delay_msecs(
1834         struct t10_alua_tg_pt_gp *tg_pt_gp,
1835         char *page)
1836 {
1837         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1838 }
1839
1840 ssize_t core_alua_store_trans_delay_msecs(
1841         struct t10_alua_tg_pt_gp *tg_pt_gp,
1842         const char *page,
1843         size_t count)
1844 {
1845         unsigned long tmp;
1846         int ret;
1847
1848         ret = strict_strtoul(page, 0, &tmp);
1849         if (ret < 0) {
1850                 pr_err("Unable to extract trans_delay_msecs\n");
1851                 return -EINVAL;
1852         }
1853         if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1854                 pr_err("Passed trans_delay_msecs: %lu, exceeds"
1855                         " ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1856                         ALUA_MAX_TRANS_DELAY_MSECS);
1857                 return -EINVAL;
1858         }
1859         tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1860
1861         return count;
1862 }
1863
1864 ssize_t core_alua_show_preferred_bit(
1865         struct t10_alua_tg_pt_gp *tg_pt_gp,
1866         char *page)
1867 {
1868         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1869 }
1870
1871 ssize_t core_alua_store_preferred_bit(
1872         struct t10_alua_tg_pt_gp *tg_pt_gp,
1873         const char *page,
1874         size_t count)
1875 {
1876         unsigned long tmp;
1877         int ret;
1878
1879         ret = strict_strtoul(page, 0, &tmp);
1880         if (ret < 0) {
1881                 pr_err("Unable to extract preferred ALUA value\n");
1882                 return -EINVAL;
1883         }
1884         if ((tmp != 0) && (tmp != 1)) {
1885                 pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1886                 return -EINVAL;
1887         }
1888         tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1889
1890         return count;
1891 }
1892
1893 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1894 {
1895         if (!lun->lun_sep)
1896                 return -ENODEV;
1897
1898         return sprintf(page, "%d\n",
1899                 atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1900 }
1901
1902 ssize_t core_alua_store_offline_bit(
1903         struct se_lun *lun,
1904         const char *page,
1905         size_t count)
1906 {
1907         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1908         unsigned long tmp;
1909         int ret;
1910
1911         if (!lun->lun_sep)
1912                 return -ENODEV;
1913
1914         ret = strict_strtoul(page, 0, &tmp);
1915         if (ret < 0) {
1916                 pr_err("Unable to extract alua_tg_pt_offline value\n");
1917                 return -EINVAL;
1918         }
1919         if ((tmp != 0) && (tmp != 1)) {
1920                 pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1921                                 tmp);
1922                 return -EINVAL;
1923         }
1924         tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1925         if (!tg_pt_gp_mem) {
1926                 pr_err("Unable to locate *tg_pt_gp_mem\n");
1927                 return -EINVAL;
1928         }
1929
1930         ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1931                         lun->lun_sep, 0, (int)tmp);
1932         if (ret < 0)
1933                 return -EINVAL;
1934
1935         return count;
1936 }
1937
1938 ssize_t core_alua_show_secondary_status(
1939         struct se_lun *lun,
1940         char *page)
1941 {
1942         return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1943 }
1944
1945 ssize_t core_alua_store_secondary_status(
1946         struct se_lun *lun,
1947         const char *page,
1948         size_t count)
1949 {
1950         unsigned long tmp;
1951         int ret;
1952
1953         ret = strict_strtoul(page, 0, &tmp);
1954         if (ret < 0) {
1955                 pr_err("Unable to extract alua_tg_pt_status\n");
1956                 return -EINVAL;
1957         }
1958         if ((tmp != ALUA_STATUS_NONE) &&
1959             (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
1960             (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
1961                 pr_err("Illegal value for alua_tg_pt_status: %lu\n",
1962                                 tmp);
1963                 return -EINVAL;
1964         }
1965         lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
1966
1967         return count;
1968 }
1969
1970 ssize_t core_alua_show_secondary_write_metadata(
1971         struct se_lun *lun,
1972         char *page)
1973 {
1974         return sprintf(page, "%d\n",
1975                         lun->lun_sep->sep_tg_pt_secondary_write_md);
1976 }
1977
1978 ssize_t core_alua_store_secondary_write_metadata(
1979         struct se_lun *lun,
1980         const char *page,
1981         size_t count)
1982 {
1983         unsigned long tmp;
1984         int ret;
1985
1986         ret = strict_strtoul(page, 0, &tmp);
1987         if (ret < 0) {
1988                 pr_err("Unable to extract alua_tg_pt_write_md\n");
1989                 return -EINVAL;
1990         }
1991         if ((tmp != 0) && (tmp != 1)) {
1992                 pr_err("Illegal value for alua_tg_pt_write_md:"
1993                                 " %lu\n", tmp);
1994                 return -EINVAL;
1995         }
1996         lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
1997
1998         return count;
1999 }
2000
2001 int core_setup_alua(struct se_device *dev, int force_pt)
2002 {
2003         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
2004         struct t10_alua *alua = &su_dev->t10_alua;
2005         struct t10_alua_lu_gp_member *lu_gp_mem;
2006         /*
2007          * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
2008          * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
2009          * cause a problem because libata and some SATA RAID HBAs appear
2010          * under Linux/SCSI, but emulate SCSI logic themselves.
2011          */
2012         if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
2013             !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
2014                 alua->alua_type = SPC_ALUA_PASSTHROUGH;
2015                 alua->alua_state_check = &core_alua_state_check_nop;
2016                 pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
2017                         " emulation\n", dev->transport->name);
2018                 return 0;
2019         }
2020         /*
2021          * If SPC-3 or above is reported by real or emulated struct se_device,
2022          * use emulated ALUA.
2023          */
2024         if (dev->transport->get_device_rev(dev) >= SCSI_3) {
2025                 pr_debug("%s: Enabling ALUA Emulation for SPC-3"
2026                         " device\n", dev->transport->name);
2027                 /*
2028                  * Associate this struct se_device with the default ALUA
2029                  * LUN Group.
2030                  */
2031                 lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2032                 if (IS_ERR(lu_gp_mem))
2033                         return PTR_ERR(lu_gp_mem);
2034
2035                 alua->alua_type = SPC3_ALUA_EMULATED;
2036                 alua->alua_state_check = &core_alua_state_check;
2037                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2038                 __core_alua_attach_lu_gp_mem(lu_gp_mem,
2039                                 default_lu_gp);
2040                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2041
2042                 pr_debug("%s: Adding to default ALUA LU Group:"
2043                         " core/alua/lu_gps/default_lu_gp\n",
2044                         dev->transport->name);
2045         } else {
2046                 alua->alua_type = SPC2_ALUA_DISABLED;
2047                 alua->alua_state_check = &core_alua_state_check_nop;
2048                 pr_debug("%s: Disabling ALUA Emulation for SPC-2"
2049                         " device\n", dev->transport->name);
2050         }
2051
2052         return 0;
2053 }