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_backend.h>
  37 #include <target/target_core_fabric.h>
  38 #include <target/target_core_configfs.h>
  39
  40 #include "target_core_internal.h"
  41 #include "target_core_alua.h"
  42 #include "target_core_ua.h"
  43
  44 static int core_alua_check_transition(int state, int *primary);
  45 static int core_alua_set_tg_pt_secondary_state(
  46                 struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
  47                 struct se_port *port, int explict, int offline);
  48
  49 static u16 alua_lu_gps_counter;
  50 static u32 alua_lu_gps_count;
  51
  52 static DEFINE_SPINLOCK(lu_gps_lock);
  53 static LIST_HEAD(lu_gps_list);
  54
  55 struct t10_alua_lu_gp *default_lu_gp;
  56
  57 /*
  58  * REPORT_TARGET_PORT_GROUPS
  59  *
  60  * See spc4r17 section 6.27
  61  */
  62 int target_emulate_report_target_port_groups(struct se_task *task)
  63 {
  64         struct se_cmd *cmd = task->task_se_cmd;
  65         struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
  66         struct se_port *port;
  67         struct t10_alua_tg_pt_gp *tg_pt_gp;
  68         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
  69         unsigned char *buf;
  70         u32 rd_len = 0, off = 4; /* Skip over RESERVED area to first
  71                                     Target port group descriptor */
  72         /*
  73          * Need at least 4 bytes of response data or else we can't
  74          * even fit the return data length.
  75          */
  76         if (cmd->data_length < 4) {
  77                 pr_warn("REPORT TARGET PORT GROUPS allocation length %u"
  78                         " too small\n", cmd->data_length);
  79                 return -EINVAL;
  80         }
  81
  82         buf = transport_kmap_data_sg(cmd);
  83
  84         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
  85         list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
  86                         tg_pt_gp_list) {
  87                 /*
  88                  * Check if the Target port group and Target port descriptor list
  89                  * based on tg_pt_gp_members count will fit into the response payload.
  90                  * Otherwise, bump rd_len to let the initiator know we have exceeded
  91                  * the allocation length and the response is truncated.
  92                  */
  93                 if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
  94                      cmd->data_length) {
  95                         rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
  96                         continue;
  97                 }
  98                 /*
  99                  * PREF: Preferred target port bit, determine if this
 100                  * bit should be set for port group.
 101                  */
 102                 if (tg_pt_gp->tg_pt_gp_pref)
 103                         buf[off] = 0x80;
 104                 /*
 105                  * Set the ASYMMETRIC ACCESS State
 106                  */
 107                 buf[off++] |= (atomic_read(
 108                         &tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
 109                 /*
 110                  * Set supported ASYMMETRIC ACCESS State bits
 111                  */
 112                 buf[off] = 0x80; /* T_SUP */
 113                 buf[off] |= 0x40; /* O_SUP */
 114                 buf[off] |= 0x8; /* U_SUP */
 115                 buf[off] |= 0x4; /* S_SUP */
 116                 buf[off] |= 0x2; /* AN_SUP */
 117                 buf[off++] |= 0x1; /* AO_SUP */
 118                 /*
 119                  * TARGET PORT GROUP
 120                  */
 121                 buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
 122                 buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
 123
 124                 off++; /* Skip over Reserved */
 125                 /*
 126                  * STATUS CODE
 127                  */
 128                 buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
 129                 /*
 130                  * Vendor Specific field
 131                  */
 132                 buf[off++] = 0x00;
 133                 /*
 134                  * TARGET PORT COUNT
 135                  */
 136                 buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
 137                 rd_len += 8;
 138
 139                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 140                 list_for_each_entry(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
 141                                 tg_pt_gp_mem_list) {
 142                         port = tg_pt_gp_mem->tg_pt;
 143                         /*
 144                          * Start Target Port descriptor format
 145                          *
 146                          * See spc4r17 section 6.2.7 Table 247
 147                          */
 148                         off += 2; /* Skip over Obsolete */
 149                         /*
 150                          * Set RELATIVE TARGET PORT IDENTIFIER
 151                          */
 152                         buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
 153                         buf[off++] = (port->sep_rtpi & 0xff);
 154                         rd_len += 4;
 155                 }
 156                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 157         }
 158         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 159         /*
 160          * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 161          */
 162         buf[0] = ((rd_len >> 24) & 0xff);
 163         buf[1] = ((rd_len >> 16) & 0xff);
 164         buf[2] = ((rd_len >> 8) & 0xff);
 165         buf[3] = (rd_len & 0xff);
 166
 167         transport_kunmap_data_sg(cmd);
 168
 169         task->task_scsi_status = GOOD;
 170         transport_complete_task(task, 1);
 171         return 0;
 172 }
 173
 174 /*
 175  * SET_TARGET_PORT_GROUPS for explict ALUA operation.
 176  *
 177  * See spc4r17 section 6.35
 178  */
 179 int target_emulate_set_target_port_groups(struct se_task *task)
 180 {
 181         struct se_cmd *cmd = task->task_se_cmd;
 182         struct se_device *dev = cmd->se_dev;
 183         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
 184         struct se_port *port, *l_port = cmd->se_lun->lun_sep;
 185         struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
 186         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
 187         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
 188         unsigned char *buf;
 189         unsigned char *ptr;
 190         u32 len = 4; /* Skip over RESERVED area in header */
 191         int alua_access_state, primary = 0, rc;
 192         u16 tg_pt_id, rtpi;
 193
 194         if (!l_port) {
 195                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 196                 return -EINVAL;
 197         }
 198         buf = transport_kmap_data_sg(cmd);
 199
 200         /*
 201          * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
 202          * for the local tg_pt_gp.
 203          */
 204         l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
 205         if (!l_tg_pt_gp_mem) {
 206                 pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
 207                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 208                 rc = -EINVAL;
 209                 goto out;
 210         }
 211         spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 212         l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
 213         if (!l_tg_pt_gp) {
 214                 spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 215                 pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
 216                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 217                 rc = -EINVAL;
 218                 goto out;
 219         }
 220         rc = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
 221         spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 222
 223         if (!rc) {
 224                 pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
 225                                 " while TPGS_EXPLICT_ALUA is disabled\n");
 226                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 227                 rc = -EINVAL;
 228                 goto out;
 229         }
 230
 231         ptr = &buf[4]; /* Skip over RESERVED area in header */
 232
 233         while (len < cmd->data_length) {
 234                 alua_access_state = (ptr[0] & 0x0f);
 235                 /*
 236                  * Check the received ALUA access state, and determine if
 237                  * the state is a primary or secondary target port asymmetric
 238                  * access state.
 239                  */
 240                 rc = core_alua_check_transition(alua_access_state, &primary);
 241                 if (rc != 0) {
 242                         /*
 243                          * If the SET TARGET PORT GROUPS attempts to establish
 244                          * an invalid combination of target port asymmetric
 245                          * access states or attempts to establish an
 246                          * unsupported target port asymmetric access state,
 247                          * then the command shall be terminated with CHECK
 248                          * CONDITION status, with the sense key set to ILLEGAL
 249                          * REQUEST, and the additional sense code set to INVALID
 250                          * FIELD IN PARAMETER LIST.
 251                          */
 252                         cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 253                         rc = -EINVAL;
 254                         goto out;
 255                 }
 256                 rc = -1;
 257                 /*
 258                  * If the ASYMMETRIC ACCESS STATE field (see table 267)
 259                  * specifies a primary target port asymmetric access state,
 260                  * then the TARGET PORT GROUP OR TARGET PORT field specifies
 261                  * a primary target port group for which the primary target
 262                  * port asymmetric access state shall be changed. If the
 263                  * ASYMMETRIC ACCESS STATE field specifies a secondary target
 264                  * port asymmetric access state, then the TARGET PORT GROUP OR
 265                  * TARGET PORT field specifies the relative target port
 266                  * identifier (see 3.1.120) of the target port for which the
 267                  * secondary target port asymmetric access state shall be
 268                  * changed.
 269                  */
 270                 if (primary) {
 271                         tg_pt_id = get_unaligned_be16(ptr + 2);
 272                         /*
 273                          * Locate the matching target port group ID from
 274                          * the global tg_pt_gp list
 275                          */
 276                         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 277                         list_for_each_entry(tg_pt_gp,
 278                                         &su_dev->t10_alua.tg_pt_gps_list,
 279                                         tg_pt_gp_list) {
 280                                 if (!tg_pt_gp->tg_pt_gp_valid_id)
 281                                         continue;
 282
 283                                 if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
 284                                         continue;
 285
 286                                 atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 287                                 smp_mb__after_atomic_inc();
 288                                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 289
 290                                 rc = core_alua_do_port_transition(tg_pt_gp,
 291                                                 dev, l_port, nacl,
 292                                                 alua_access_state, 1);
 293
 294                                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 295                                 atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
 296                                 smp_mb__after_atomic_dec();
 297                                 break;
 298                         }
 299                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 300                         /*
 301                          * If not matching target port group ID can be located
 302                          * throw an exception with ASCQ: INVALID_PARAMETER_LIST
 303                          */
 304                         if (rc != 0) {
 305                                 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 306                                 rc = -EINVAL;
 307                                 goto out;
 308                         }
 309                 } else {
 310                         /*
 311                          * Extact the RELATIVE TARGET PORT IDENTIFIER to identify
 312                          * the Target Port in question for the the incoming
 313                          * SET_TARGET_PORT_GROUPS op.
 314                          */
 315                         rtpi = get_unaligned_be16(ptr + 2);
 316                         /*
 317                          * Locate the matching relative target port identifer
 318                          * for the struct se_device storage object.
 319                          */
 320                         spin_lock(&dev->se_port_lock);
 321                         list_for_each_entry(port, &dev->dev_sep_list,
 322                                                         sep_list) {
 323                                 if (port->sep_rtpi != rtpi)
 324                                         continue;
 325
 326                                 tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 327                                 spin_unlock(&dev->se_port_lock);
 328
 329                                 rc = core_alua_set_tg_pt_secondary_state(
 330                                                 tg_pt_gp_mem, port, 1, 1);
 331
 332                                 spin_lock(&dev->se_port_lock);
 333                                 break;
 334                         }
 335                         spin_unlock(&dev->se_port_lock);
 336                         /*
 337                          * If not matching relative target port identifier can
 338                          * be located, throw an exception with ASCQ:
 339                          * INVALID_PARAMETER_LIST
 340                          */
 341                         if (rc != 0) {
 342                                 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 343                                 rc = -EINVAL;
 344                                 goto out;
 345                         }
 346                 }
 347
 348                 ptr += 4;
 349                 len += 4;
 350         }
 351
 352 out:
 353         transport_kunmap_data_sg(cmd);
 354         task->task_scsi_status = GOOD;
 355         transport_complete_task(task, 1);
 356         return 0;
 357 }
 358
 359 static inline int core_alua_state_nonoptimized(
 360         struct se_cmd *cmd,
 361         unsigned char *cdb,
 362         int nonop_delay_msecs,
 363         u8 *alua_ascq)
 364 {
 365         /*
 366          * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
 367          * later to determine if processing of this cmd needs to be
 368          * temporarily delayed for the Active/NonOptimized primary access state.
 369          */
 370         cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
 371         cmd->alua_nonop_delay = nonop_delay_msecs;
 372         return 0;
 373 }
 374
 375 static inline int core_alua_state_standby(
 376         struct se_cmd *cmd,
 377         unsigned char *cdb,
 378         u8 *alua_ascq)
 379 {
 380         /*
 381          * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
 382          * spc4r17 section 5.9.2.4.4
 383          */
 384         switch (cdb[0]) {
 385         case INQUIRY:
 386         case LOG_SELECT:
 387         case LOG_SENSE:
 388         case MODE_SELECT:
 389         case MODE_SENSE:
 390         case REPORT_LUNS:
 391         case RECEIVE_DIAGNOSTIC:
 392         case SEND_DIAGNOSTIC:
 393         case MAINTENANCE_IN:
 394                 switch (cdb[1]) {
 395                 case MI_REPORT_TARGET_PGS:
 396                         return 0;
 397                 default:
 398                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 399                         return 1;
 400                 }
 401         case MAINTENANCE_OUT:
 402                 switch (cdb[1]) {
 403                 case MO_SET_TARGET_PGS:
 404                         return 0;
 405                 default:
 406                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 407                         return 1;
 408                 }
 409         case REQUEST_SENSE:
 410         case PERSISTENT_RESERVE_IN:
 411         case PERSISTENT_RESERVE_OUT:
 412         case READ_BUFFER:
 413         case WRITE_BUFFER:
 414                 return 0;
 415         default:
 416                 *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 417                 return 1;
 418         }
 419
 420         return 0;
 421 }
 422
 423 static inline int core_alua_state_unavailable(
 424         struct se_cmd *cmd,
 425         unsigned char *cdb,
 426         u8 *alua_ascq)
 427 {
 428         /*
 429          * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
 430          * spc4r17 section 5.9.2.4.5
 431          */
 432         switch (cdb[0]) {
 433         case INQUIRY:
 434         case REPORT_LUNS:
 435         case MAINTENANCE_IN:
 436                 switch (cdb[1]) {
 437                 case MI_REPORT_TARGET_PGS:
 438                         return 0;
 439                 default:
 440                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 441                         return 1;
 442                 }
 443         case MAINTENANCE_OUT:
 444                 switch (cdb[1]) {
 445                 case MO_SET_TARGET_PGS:
 446                         return 0;
 447                 default:
 448                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 449                         return 1;
 450                 }
 451         case REQUEST_SENSE:
 452         case READ_BUFFER:
 453         case WRITE_BUFFER:
 454                 return 0;
 455         default:
 456                 *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 457                 return 1;
 458         }
 459
 460         return 0;
 461 }
 462
 463 static inline int core_alua_state_transition(
 464         struct se_cmd *cmd,
 465         unsigned char *cdb,
 466         u8 *alua_ascq)
 467 {
 468         /*
 469          * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
 470          * spc4r17 section 5.9.2.5
 471          */
 472         switch (cdb[0]) {
 473         case INQUIRY:
 474         case REPORT_LUNS:
 475         case MAINTENANCE_IN:
 476                 switch (cdb[1]) {
 477                 case MI_REPORT_TARGET_PGS:
 478                         return 0;
 479                 default:
 480                         *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 481                         return 1;
 482                 }
 483         case REQUEST_SENSE:
 484         case READ_BUFFER:
 485         case WRITE_BUFFER:
 486                 return 0;
 487         default:
 488                 *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 489                 return 1;
 490         }
 491
 492         return 0;
 493 }
 494
 495 /*
 496  * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
 497  * in transport_cmd_sequencer().  This function is assigned to
 498  * struct t10_alua *->state_check() in core_setup_alua()
 499  */
 500 static int core_alua_state_check_nop(
 501         struct se_cmd *cmd,
 502         unsigned char *cdb,
 503         u8 *alua_ascq)
 504 {
 505         return 0;
 506 }
 507
 508 /*
 509  * Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
 510  * This function is assigned to struct t10_alua *->state_check() in
 511  * core_setup_alua()
 512  *
 513  * Also, this function can return three different return codes to
 514  * signal transport_generic_cmd_sequencer()
 515  *
 516  * return 1: Is used to signal LUN not accecsable, and check condition/not ready
 517  * return 0: Used to signal success
 518  * reutrn -1: Used to signal failure, and invalid cdb field
 519  */
 520 static int core_alua_state_check(
 521         struct se_cmd *cmd,
 522         unsigned char *cdb,
 523         u8 *alua_ascq)
 524 {
 525         struct se_lun *lun = cmd->se_lun;
 526         struct se_port *port = lun->lun_sep;
 527         struct t10_alua_tg_pt_gp *tg_pt_gp;
 528         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
 529         int out_alua_state, nonop_delay_msecs;
 530
 531         if (!port)
 532                 return 0;
 533         /*
 534          * First, check for a struct se_port specific secondary ALUA target port
 535          * access state: OFFLINE
 536          */
 537         if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
 538                 *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 539                 pr_debug("ALUA: Got secondary offline status for local"
 540                                 " target port\n");
 541                 *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 542                 return 1;
 543         }
 544          /*
 545          * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
 546          * ALUA target port group, to obtain current ALUA access state.
 547          * Otherwise look for the underlying struct se_device association with
 548          * a ALUA logical unit group.
 549          */
 550         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 551         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 552         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
 553         out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 554         nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
 555         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 556         /*
 557          * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a separate conditional
 558          * statement so the compiler knows explicitly to check this case first.
 559          * For the Optimized ALUA access state case, we want to process the
 560          * incoming fabric cmd ASAP..
 561          */
 562         if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
 563                 return 0;
 564
 565         switch (out_alua_state) {
 566         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 567                 return core_alua_state_nonoptimized(cmd, cdb,
 568                                         nonop_delay_msecs, alua_ascq);
 569         case ALUA_ACCESS_STATE_STANDBY:
 570                 return core_alua_state_standby(cmd, cdb, alua_ascq);
 571         case ALUA_ACCESS_STATE_UNAVAILABLE:
 572                 return core_alua_state_unavailable(cmd, cdb, alua_ascq);
 573         case ALUA_ACCESS_STATE_TRANSITION:
 574                 return core_alua_state_transition(cmd, cdb, alua_ascq);
 575         /*
 576          * OFFLINE is a secondary ALUA target port group access state, that is
 577          * handled above with struct se_port->sep_tg_pt_secondary_offline=1
 578          */
 579         case ALUA_ACCESS_STATE_OFFLINE:
 580         default:
 581                 pr_err("Unknown ALUA access state: 0x%02x\n",
 582                                 out_alua_state);
 583                 return -EINVAL;
 584         }
 585
 586         return 0;
 587 }
 588
 589 /*
 590  * Check implict and explict ALUA state change request.
 591  */
 592 static int core_alua_check_transition(int state, int *primary)
 593 {
 594         switch (state) {
 595         case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 596         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 597         case ALUA_ACCESS_STATE_STANDBY:
 598         case ALUA_ACCESS_STATE_UNAVAILABLE:
 599                 /*
 600                  * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
 601                  * defined as primary target port asymmetric access states.
 602                  */
 603                 *primary = 1;
 604                 break;
 605         case ALUA_ACCESS_STATE_OFFLINE:
 606                 /*
 607                  * OFFLINE state is defined as a secondary target port
 608                  * asymmetric access state.
 609                  */
 610                 *primary = 0;
 611                 break;
 612         default:
 613                 pr_err("Unknown ALUA access state: 0x%02x\n", state);
 614                 return -EINVAL;
 615         }
 616
 617         return 0;
 618 }
 619
 620 static char *core_alua_dump_state(int state)
 621 {
 622         switch (state) {
 623         case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 624                 return "Active/Optimized";
 625         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 626                 return "Active/NonOptimized";
 627         case ALUA_ACCESS_STATE_STANDBY:
 628                 return "Standby";
 629         case ALUA_ACCESS_STATE_UNAVAILABLE:
 630                 return "Unavailable";
 631         case ALUA_ACCESS_STATE_OFFLINE:
 632                 return "Offline";
 633         default:
 634                 return "Unknown";
 635         }
 636
 637         return NULL;
 638 }
 639
 640 char *core_alua_dump_status(int status)
 641 {
 642         switch (status) {
 643         case ALUA_STATUS_NONE:
 644                 return "None";
 645         case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
 646                 return "Altered by Explict STPG";
 647         case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
 648                 return "Altered by Implict ALUA";
 649         default:
 650                 return "Unknown";
 651         }
 652
 653         return NULL;
 654 }
 655
 656 /*
 657  * Used by fabric modules to determine when we need to delay processing
 658  * for the Active/NonOptimized paths..
 659  */
 660 int core_alua_check_nonop_delay(
 661         struct se_cmd *cmd)
 662 {
 663         if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
 664                 return 0;
 665         if (in_interrupt())
 666                 return 0;
 667         /*
 668          * The ALUA Active/NonOptimized access state delay can be disabled
 669          * in via configfs with a value of zero
 670          */
 671         if (!cmd->alua_nonop_delay)
 672                 return 0;
 673         /*
 674          * struct se_cmd->alua_nonop_delay gets set by a target port group
 675          * defined interval in core_alua_state_nonoptimized()
 676          */
 677         msleep_interruptible(cmd->alua_nonop_delay);
 678         return 0;
 679 }
 680 EXPORT_SYMBOL(core_alua_check_nonop_delay);
 681
 682 /*
 683  * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
 684  *
 685  */
 686 static int core_alua_write_tpg_metadata(
 687         const char *path,
 688         unsigned char *md_buf,
 689         u32 md_buf_len)
 690 {
 691         mm_segment_t old_fs;
 692         struct file *file;
 693         struct iovec iov[1];
 694         int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
 695
 696         memset(iov, 0, sizeof(struct iovec));
 697
 698         file = filp_open(path, flags, 0600);
 699         if (IS_ERR(file) || !file || !file->f_dentry) {
 700                 pr_err("filp_open(%s) for ALUA metadata failed\n",
 701                         path);
 702                 return -ENODEV;
 703         }
 704
 705         iov[0].iov_base = &md_buf[0];
 706         iov[0].iov_len = md_buf_len;
 707
 708         old_fs = get_fs();
 709         set_fs(get_ds());
 710         ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
 711         set_fs(old_fs);
 712
 713         if (ret < 0) {
 714                 pr_err("Error writing ALUA metadata file: %s\n", path);
 715                 filp_close(file, NULL);
 716                 return -EIO;
 717         }
 718         filp_close(file, NULL);
 719
 720         return 0;
 721 }
 722
 723 /*
 724  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
 725  */
 726 static int core_alua_update_tpg_primary_metadata(
 727         struct t10_alua_tg_pt_gp *tg_pt_gp,
 728         int primary_state,
 729         unsigned char *md_buf)
 730 {
 731         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
 732         struct t10_wwn *wwn = &su_dev->t10_wwn;
 733         char path[ALUA_METADATA_PATH_LEN];
 734         int len;
 735
 736         memset(path, 0, ALUA_METADATA_PATH_LEN);
 737
 738         len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
 739                         "tg_pt_gp_id=%hu\n"
 740                         "alua_access_state=0x%02x\n"
 741                         "alua_access_status=0x%02x\n",
 742                         tg_pt_gp->tg_pt_gp_id, primary_state,
 743                         tg_pt_gp->tg_pt_gp_alua_access_status);
 744
 745         snprintf(path, ALUA_METADATA_PATH_LEN,
 746                 "/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
 747                 config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 748
 749         return core_alua_write_tpg_metadata(path, md_buf, len);
 750 }
 751
 752 static int core_alua_do_transition_tg_pt(
 753         struct t10_alua_tg_pt_gp *tg_pt_gp,
 754         struct se_port *l_port,
 755         struct se_node_acl *nacl,
 756         unsigned char *md_buf,
 757         int new_state,
 758         int explict)
 759 {
 760         struct se_dev_entry *se_deve;
 761         struct se_lun_acl *lacl;
 762         struct se_port *port;
 763         struct t10_alua_tg_pt_gp_member *mem;
 764         int old_state = 0;
 765         /*
 766          * Save the old primary ALUA access state, and set the current state
 767          * to ALUA_ACCESS_STATE_TRANSITION.
 768          */
 769         old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 770         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
 771                         ALUA_ACCESS_STATE_TRANSITION);
 772         tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
 773                                 ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
 774                                 ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
 775         /*
 776          * Check for the optional ALUA primary state transition delay
 777          */
 778         if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
 779                 msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
 780
 781         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 782         list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
 783                                 tg_pt_gp_mem_list) {
 784                 port = mem->tg_pt;
 785                 /*
 786                  * After an implicit target port asymmetric access state
 787                  * change, a device server shall establish a unit attention
 788                  * condition for the initiator port associated with every I_T
 789                  * nexus with the additional sense code set to ASYMMETRIC
 790                  * ACCESS STATE CHAGED.
 791                  *
 792                  * After an explicit target port asymmetric access state
 793                  * change, a device server shall establish a unit attention
 794                  * condition with the additional sense code set to ASYMMETRIC
 795                  * ACCESS STATE CHANGED for the initiator port associated with
 796                  * every I_T nexus other than the I_T nexus on which the SET
 797                  * TARGET PORT GROUPS command
 798                  */
 799                 atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
 800                 smp_mb__after_atomic_inc();
 801                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 802
 803                 spin_lock_bh(&port->sep_alua_lock);
 804                 list_for_each_entry(se_deve, &port->sep_alua_list,
 805                                         alua_port_list) {
 806                         lacl = se_deve->se_lun_acl;
 807                         /*
 808                          * se_deve->se_lun_acl pointer may be NULL for a
 809                          * entry created without explict Node+MappedLUN ACLs
 810                          */
 811                         if (!lacl)
 812                                 continue;
 813
 814                         if (explict &&
 815                            (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
 816                            (l_port != NULL) && (l_port == port))
 817                                 continue;
 818
 819                         core_scsi3_ua_allocate(lacl->se_lun_nacl,
 820                                 se_deve->mapped_lun, 0x2A,
 821                                 ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
 822                 }
 823                 spin_unlock_bh(&port->sep_alua_lock);
 824
 825                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 826                 atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
 827                 smp_mb__after_atomic_dec();
 828         }
 829         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 830         /*
 831          * Update the ALUA metadata buf that has been allocated in
 832          * core_alua_do_port_transition(), this metadata will be written
 833          * to struct file.
 834          *
 835          * Note that there is the case where we do not want to update the
 836          * metadata when the saved metadata is being parsed in userspace
 837          * when setting the existing port access state and access status.
 838          *
 839          * Also note that the failure to write out the ALUA metadata to
 840          * struct file does NOT affect the actual ALUA transition.
 841          */
 842         if (tg_pt_gp->tg_pt_gp_write_metadata) {
 843                 mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
 844                 core_alua_update_tpg_primary_metadata(tg_pt_gp,
 845                                         new_state, md_buf);
 846                 mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
 847         }
 848         /*
 849          * Set the current primary ALUA access state to the requested new state
 850          */
 851         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
 852
 853         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
 854                 " from primary access state %s to %s\n", (explict) ? "explict" :
 855                 "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
 856                 tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
 857                 core_alua_dump_state(new_state));
 858
 859         return 0;
 860 }
 861
 862 int core_alua_do_port_transition(
 863         struct t10_alua_tg_pt_gp *l_tg_pt_gp,
 864         struct se_device *l_dev,
 865         struct se_port *l_port,
 866         struct se_node_acl *l_nacl,
 867         int new_state,
 868         int explict)
 869 {
 870         struct se_device *dev;
 871         struct se_port *port;
 872         struct se_subsystem_dev *su_dev;
 873         struct se_node_acl *nacl;
 874         struct t10_alua_lu_gp *lu_gp;
 875         struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
 876         struct t10_alua_tg_pt_gp *tg_pt_gp;
 877         unsigned char *md_buf;
 878         int primary;
 879
 880         if (core_alua_check_transition(new_state, &primary) != 0)
 881                 return -EINVAL;
 882
 883         md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
 884         if (!md_buf) {
 885                 pr_err("Unable to allocate buf for ALUA metadata\n");
 886                 return -ENOMEM;
 887         }
 888
 889         local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
 890         spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
 891         lu_gp = local_lu_gp_mem->lu_gp;
 892         atomic_inc(&lu_gp->lu_gp_ref_cnt);
 893         smp_mb__after_atomic_inc();
 894         spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
 895         /*
 896          * For storage objects that are members of the 'default_lu_gp',
 897          * we only do transition on the passed *l_tp_pt_gp, and not
 898          * on all of the matching target port groups IDs in default_lu_gp.
 899          */
 900         if (!lu_gp->lu_gp_id) {
 901                 /*
 902                  * core_alua_do_transition_tg_pt() will always return
 903                  * success.
 904                  */
 905                 core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
 906                                         md_buf, new_state, explict);
 907                 atomic_dec(&lu_gp->lu_gp_ref_cnt);
 908                 smp_mb__after_atomic_dec();
 909                 kfree(md_buf);
 910                 return 0;
 911         }
 912         /*
 913          * For all other LU groups aside from 'default_lu_gp', walk all of
 914          * the associated storage objects looking for a matching target port
 915          * group ID from the local target port group.
 916          */
 917         spin_lock(&lu_gp->lu_gp_lock);
 918         list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
 919                                 lu_gp_mem_list) {
 920
 921                 dev = lu_gp_mem->lu_gp_mem_dev;
 922                 su_dev = dev->se_sub_dev;
 923                 atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
 924                 smp_mb__after_atomic_inc();
 925                 spin_unlock(&lu_gp->lu_gp_lock);
 926
 927                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 928                 list_for_each_entry(tg_pt_gp,
 929                                 &su_dev->t10_alua.tg_pt_gps_list,
 930                                 tg_pt_gp_list) {
 931
 932                         if (!tg_pt_gp->tg_pt_gp_valid_id)
 933                                 continue;
 934                         /*
 935                          * If the target behavior port asymmetric access state
 936                          * is changed for any target port group accessiable via
 937                          * a logical unit within a LU group, the target port
 938                          * behavior group asymmetric access states for the same
 939                          * target port group accessible via other logical units
 940                          * in that LU group will also change.
 941                          */
 942                         if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
 943                                 continue;
 944
 945                         if (l_tg_pt_gp == tg_pt_gp) {
 946                                 port = l_port;
 947                                 nacl = l_nacl;
 948                         } else {
 949                                 port = NULL;
 950                                 nacl = NULL;
 951                         }
 952                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 953                         smp_mb__after_atomic_inc();
 954                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 955                         /*
 956                          * core_alua_do_transition_tg_pt() will always return
 957                          * success.
 958                          */
 959                         core_alua_do_transition_tg_pt(tg_pt_gp, port,
 960                                         nacl, md_buf, new_state, explict);
 961
 962                         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 963                         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
 964                         smp_mb__after_atomic_dec();
 965                 }
 966                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 967
 968                 spin_lock(&lu_gp->lu_gp_lock);
 969                 atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
 970                 smp_mb__after_atomic_dec();
 971         }
 972         spin_unlock(&lu_gp->lu_gp_lock);
 973
 974         pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
 975                 " Group IDs: %hu %s transition to primary state: %s\n",
 976                 config_item_name(&lu_gp->lu_gp_group.cg_item),
 977                 l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
 978                 core_alua_dump_state(new_state));
 979
 980         atomic_dec(&lu_gp->lu_gp_ref_cnt);
 981         smp_mb__after_atomic_dec();
 982         kfree(md_buf);
 983         return 0;
 984 }
 985
 986 /*
 987  * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
 988  */
 989 static int core_alua_update_tpg_secondary_metadata(
 990         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
 991         struct se_port *port,
 992         unsigned char *md_buf,
 993         u32 md_buf_len)
 994 {
 995         struct se_portal_group *se_tpg = port->sep_tpg;
 996         char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
 997         int len;
 998
 999         memset(path, 0, ALUA_METADATA_PATH_LEN);
1000         memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1001
1002         len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1003                         se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1004
1005         if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1006                 snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1007                                 se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1008
1009         len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1010                         "alua_tg_pt_status=0x%02x\n",
1011                         atomic_read(&port->sep_tg_pt_secondary_offline),
1012                         port->sep_tg_pt_secondary_stat);
1013
1014         snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1015                         se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1016                         port->sep_lun->unpacked_lun);
1017
1018         return core_alua_write_tpg_metadata(path, md_buf, len);
1019 }
1020
1021 static int core_alua_set_tg_pt_secondary_state(
1022         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1023         struct se_port *port,
1024         int explict,
1025         int offline)
1026 {
1027         struct t10_alua_tg_pt_gp *tg_pt_gp;
1028         unsigned char *md_buf;
1029         u32 md_buf_len;
1030         int trans_delay_msecs;
1031
1032         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1033         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1034         if (!tg_pt_gp) {
1035                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1036                 pr_err("Unable to complete secondary state"
1037                                 " transition\n");
1038                 return -EINVAL;
1039         }
1040         trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1041         /*
1042          * Set the secondary ALUA target port access state to OFFLINE
1043          * or release the previously secondary state for struct se_port
1044          */
1045         if (offline)
1046                 atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1047         else
1048                 atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1049
1050         md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1051         port->sep_tg_pt_secondary_stat = (explict) ?
1052                         ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
1053                         ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
1054
1055         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1056                 " to secondary access state: %s\n", (explict) ? "explict" :
1057                 "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1058                 tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1059
1060         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1061         /*
1062          * Do the optional transition delay after we set the secondary
1063          * ALUA access state.
1064          */
1065         if (trans_delay_msecs != 0)
1066                 msleep_interruptible(trans_delay_msecs);
1067         /*
1068          * See if we need to update the ALUA fabric port metadata for
1069          * secondary state and status
1070          */
1071         if (port->sep_tg_pt_secondary_write_md) {
1072                 md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1073                 if (!md_buf) {
1074                         pr_err("Unable to allocate md_buf for"
1075                                 " secondary ALUA access metadata\n");
1076                         return -ENOMEM;
1077                 }
1078                 mutex_lock(&port->sep_tg_pt_md_mutex);
1079                 core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1080                                 md_buf, md_buf_len);
1081                 mutex_unlock(&port->sep_tg_pt_md_mutex);
1082
1083                 kfree(md_buf);
1084         }
1085
1086         return 0;
1087 }
1088
1089 struct t10_alua_lu_gp *
1090 core_alua_allocate_lu_gp(const char *name, int def_group)
1091 {
1092         struct t10_alua_lu_gp *lu_gp;
1093
1094         lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1095         if (!lu_gp) {
1096                 pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1097                 return ERR_PTR(-ENOMEM);
1098         }
1099         INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1100         INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1101         spin_lock_init(&lu_gp->lu_gp_lock);
1102         atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1103
1104         if (def_group) {
1105                 lu_gp->lu_gp_id = alua_lu_gps_counter++;
1106                 lu_gp->lu_gp_valid_id = 1;
1107                 alua_lu_gps_count++;
1108         }
1109
1110         return lu_gp;
1111 }
1112
1113 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1114 {
1115         struct t10_alua_lu_gp *lu_gp_tmp;
1116         u16 lu_gp_id_tmp;
1117         /*
1118          * The lu_gp->lu_gp_id may only be set once..
1119          */
1120         if (lu_gp->lu_gp_valid_id) {
1121                 pr_warn("ALUA LU Group already has a valid ID,"
1122                         " ignoring request\n");
1123                 return -EINVAL;
1124         }
1125
1126         spin_lock(&lu_gps_lock);
1127         if (alua_lu_gps_count == 0x0000ffff) {
1128                 pr_err("Maximum ALUA alua_lu_gps_count:"
1129                                 " 0x0000ffff reached\n");
1130                 spin_unlock(&lu_gps_lock);
1131                 kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1132                 return -ENOSPC;
1133         }
1134 again:
1135         lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1136                                 alua_lu_gps_counter++;
1137
1138         list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1139                 if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1140                         if (!lu_gp_id)
1141                                 goto again;
1142
1143                         pr_warn("ALUA Logical Unit Group ID: %hu"
1144                                 " already exists, ignoring request\n",
1145                                 lu_gp_id);
1146                         spin_unlock(&lu_gps_lock);
1147                         return -EINVAL;
1148                 }
1149         }
1150
1151         lu_gp->lu_gp_id = lu_gp_id_tmp;
1152         lu_gp->lu_gp_valid_id = 1;
1153         list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1154         alua_lu_gps_count++;
1155         spin_unlock(&lu_gps_lock);
1156
1157         return 0;
1158 }
1159
1160 static struct t10_alua_lu_gp_member *
1161 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1162 {
1163         struct t10_alua_lu_gp_member *lu_gp_mem;
1164
1165         lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1166         if (!lu_gp_mem) {
1167                 pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1168                 return ERR_PTR(-ENOMEM);
1169         }
1170         INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1171         spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1172         atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1173
1174         lu_gp_mem->lu_gp_mem_dev = dev;
1175         dev->dev_alua_lu_gp_mem = lu_gp_mem;
1176
1177         return lu_gp_mem;
1178 }
1179
1180 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1181 {
1182         struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1183         /*
1184          * Once we have reached this point, config_item_put() has
1185          * already been called from target_core_alua_drop_lu_gp().
1186          *
1187          * Here, we remove the *lu_gp from the global list so that
1188          * no associations can be made while we are releasing
1189          * struct t10_alua_lu_gp.
1190          */
1191         spin_lock(&lu_gps_lock);
1192         list_del(&lu_gp->lu_gp_node);
1193         alua_lu_gps_count--;
1194         spin_unlock(&lu_gps_lock);
1195         /*
1196          * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1197          * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1198          * released with core_alua_put_lu_gp_from_name()
1199          */
1200         while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1201                 cpu_relax();
1202         /*
1203          * Release reference to struct t10_alua_lu_gp * from all associated
1204          * struct se_device.
1205          */
1206         spin_lock(&lu_gp->lu_gp_lock);
1207         list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1208                                 &lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1209                 if (lu_gp_mem->lu_gp_assoc) {
1210                         list_del(&lu_gp_mem->lu_gp_mem_list);
1211                         lu_gp->lu_gp_members--;
1212                         lu_gp_mem->lu_gp_assoc = 0;
1213                 }
1214                 spin_unlock(&lu_gp->lu_gp_lock);
1215                 /*
1216                  *
1217                  * lu_gp_mem is associated with a single
1218                  * struct se_device->dev_alua_lu_gp_mem, and is released when
1219                  * struct se_device is released via core_alua_free_lu_gp_mem().
1220                  *
1221                  * If the passed lu_gp does NOT match the default_lu_gp, assume
1222                  * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1223                  */
1224                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1225                 if (lu_gp != default_lu_gp)
1226                         __core_alua_attach_lu_gp_mem(lu_gp_mem,
1227                                         default_lu_gp);
1228                 else
1229                         lu_gp_mem->lu_gp = NULL;
1230                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1231
1232                 spin_lock(&lu_gp->lu_gp_lock);
1233         }
1234         spin_unlock(&lu_gp->lu_gp_lock);
1235
1236         kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1237 }
1238
1239 void core_alua_free_lu_gp_mem(struct se_device *dev)
1240 {
1241         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1242         struct t10_alua *alua = &su_dev->t10_alua;
1243         struct t10_alua_lu_gp *lu_gp;
1244         struct t10_alua_lu_gp_member *lu_gp_mem;
1245
1246         if (alua->alua_type != SPC3_ALUA_EMULATED)
1247                 return;
1248
1249         lu_gp_mem = dev->dev_alua_lu_gp_mem;
1250         if (!lu_gp_mem)
1251                 return;
1252
1253         while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1254                 cpu_relax();
1255
1256         spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1257         lu_gp = lu_gp_mem->lu_gp;
1258         if (lu_gp) {
1259                 spin_lock(&lu_gp->lu_gp_lock);
1260                 if (lu_gp_mem->lu_gp_assoc) {
1261                         list_del(&lu_gp_mem->lu_gp_mem_list);
1262                         lu_gp->lu_gp_members--;
1263                         lu_gp_mem->lu_gp_assoc = 0;
1264                 }
1265                 spin_unlock(&lu_gp->lu_gp_lock);
1266                 lu_gp_mem->lu_gp = NULL;
1267         }
1268         spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1269
1270         kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1271 }
1272
1273 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1274 {
1275         struct t10_alua_lu_gp *lu_gp;
1276         struct config_item *ci;
1277
1278         spin_lock(&lu_gps_lock);
1279         list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1280                 if (!lu_gp->lu_gp_valid_id)
1281                         continue;
1282                 ci = &lu_gp->lu_gp_group.cg_item;
1283                 if (!strcmp(config_item_name(ci), name)) {
1284                         atomic_inc(&lu_gp->lu_gp_ref_cnt);
1285                         spin_unlock(&lu_gps_lock);
1286                         return lu_gp;
1287                 }
1288         }
1289         spin_unlock(&lu_gps_lock);
1290
1291         return NULL;
1292 }
1293
1294 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1295 {
1296         spin_lock(&lu_gps_lock);
1297         atomic_dec(&lu_gp->lu_gp_ref_cnt);
1298         spin_unlock(&lu_gps_lock);
1299 }
1300
1301 /*
1302  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1303  */
1304 void __core_alua_attach_lu_gp_mem(
1305         struct t10_alua_lu_gp_member *lu_gp_mem,
1306         struct t10_alua_lu_gp *lu_gp)
1307 {
1308         spin_lock(&lu_gp->lu_gp_lock);
1309         lu_gp_mem->lu_gp = lu_gp;
1310         lu_gp_mem->lu_gp_assoc = 1;
1311         list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1312         lu_gp->lu_gp_members++;
1313         spin_unlock(&lu_gp->lu_gp_lock);
1314 }
1315
1316 /*
1317  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1318  */
1319 void __core_alua_drop_lu_gp_mem(
1320         struct t10_alua_lu_gp_member *lu_gp_mem,
1321         struct t10_alua_lu_gp *lu_gp)
1322 {
1323         spin_lock(&lu_gp->lu_gp_lock);
1324         list_del(&lu_gp_mem->lu_gp_mem_list);
1325         lu_gp_mem->lu_gp = NULL;
1326         lu_gp_mem->lu_gp_assoc = 0;
1327         lu_gp->lu_gp_members--;
1328         spin_unlock(&lu_gp->lu_gp_lock);
1329 }
1330
1331 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
1332         struct se_subsystem_dev *su_dev,
1333         const char *name,
1334         int def_group)
1335 {
1336         struct t10_alua_tg_pt_gp *tg_pt_gp;
1337
1338         tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1339         if (!tg_pt_gp) {
1340                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1341                 return NULL;
1342         }
1343         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1344         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1345         mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1346         spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1347         atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1348         tg_pt_gp->tg_pt_gp_su_dev = su_dev;
1349         tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1350         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1351                 ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1352         /*
1353          * Enable both explict and implict ALUA support by default
1354          */
1355         tg_pt_gp->tg_pt_gp_alua_access_type =
1356                         TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1357         /*
1358          * Set the default Active/NonOptimized Delay in milliseconds
1359          */
1360         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1361         tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1362
1363         if (def_group) {
1364                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1365                 tg_pt_gp->tg_pt_gp_id =
1366                                 su_dev->t10_alua.alua_tg_pt_gps_counter++;
1367                 tg_pt_gp->tg_pt_gp_valid_id = 1;
1368                 su_dev->t10_alua.alua_tg_pt_gps_count++;
1369                 list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1370                               &su_dev->t10_alua.tg_pt_gps_list);
1371                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1372         }
1373
1374         return tg_pt_gp;
1375 }
1376
1377 int core_alua_set_tg_pt_gp_id(
1378         struct t10_alua_tg_pt_gp *tg_pt_gp,
1379         u16 tg_pt_gp_id)
1380 {
1381         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1382         struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1383         u16 tg_pt_gp_id_tmp;
1384         /*
1385          * The tg_pt_gp->tg_pt_gp_id may only be set once..
1386          */
1387         if (tg_pt_gp->tg_pt_gp_valid_id) {
1388                 pr_warn("ALUA TG PT Group already has a valid ID,"
1389                         " ignoring request\n");
1390                 return -EINVAL;
1391         }
1392
1393         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1394         if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1395                 pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1396                         " 0x0000ffff reached\n");
1397                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1398                 kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1399                 return -ENOSPC;
1400         }
1401 again:
1402         tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1403                         su_dev->t10_alua.alua_tg_pt_gps_counter++;
1404
1405         list_for_each_entry(tg_pt_gp_tmp, &su_dev->t10_alua.tg_pt_gps_list,
1406                         tg_pt_gp_list) {
1407                 if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1408                         if (!tg_pt_gp_id)
1409                                 goto again;
1410
1411                         pr_err("ALUA Target Port Group ID: %hu already"
1412                                 " exists, ignoring request\n", tg_pt_gp_id);
1413                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1414                         return -EINVAL;
1415                 }
1416         }
1417
1418         tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1419         tg_pt_gp->tg_pt_gp_valid_id = 1;
1420         list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1421                         &su_dev->t10_alua.tg_pt_gps_list);
1422         su_dev->t10_alua.alua_tg_pt_gps_count++;
1423         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1424
1425         return 0;
1426 }
1427
1428 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1429         struct se_port *port)
1430 {
1431         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1432
1433         tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1434                                 GFP_KERNEL);
1435         if (!tg_pt_gp_mem) {
1436                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1437                 return ERR_PTR(-ENOMEM);
1438         }
1439         INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1440         spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1441         atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1442
1443         tg_pt_gp_mem->tg_pt = port;
1444         port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1445
1446         return tg_pt_gp_mem;
1447 }
1448
1449 void core_alua_free_tg_pt_gp(
1450         struct t10_alua_tg_pt_gp *tg_pt_gp)
1451 {
1452         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1453         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1454         /*
1455          * Once we have reached this point, config_item_put() has already
1456          * been called from target_core_alua_drop_tg_pt_gp().
1457          *
1458          * Here we remove *tg_pt_gp from the global list so that
1459          * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1460          * can be made while we are releasing struct t10_alua_tg_pt_gp.
1461          */
1462         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1463         list_del(&tg_pt_gp->tg_pt_gp_list);
1464         su_dev->t10_alua.alua_tg_pt_gps_counter--;
1465         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1466         /*
1467          * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1468          * core_alua_get_tg_pt_gp_by_name() in
1469          * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1470          * to be released with core_alua_put_tg_pt_gp_from_name().
1471          */
1472         while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1473                 cpu_relax();
1474         /*
1475          * Release reference to struct t10_alua_tg_pt_gp from all associated
1476          * struct se_port.
1477          */
1478         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1479         list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1480                         &tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1481                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1482                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1483                         tg_pt_gp->tg_pt_gp_members--;
1484                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1485                 }
1486                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1487                 /*
1488                  * tg_pt_gp_mem is associated with a single
1489                  * se_port->sep_alua_tg_pt_gp_mem, and is released via
1490                  * core_alua_free_tg_pt_gp_mem().
1491                  *
1492                  * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1493                  * assume we want to re-assocate a given tg_pt_gp_mem with
1494                  * default_tg_pt_gp.
1495                  */
1496                 spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1497                 if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
1498                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1499                                         su_dev->t10_alua.default_tg_pt_gp);
1500                 } else
1501                         tg_pt_gp_mem->tg_pt_gp = NULL;
1502                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1503
1504                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1505         }
1506         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1507
1508         kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1509 }
1510
1511 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1512 {
1513         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1514         struct t10_alua *alua = &su_dev->t10_alua;
1515         struct t10_alua_tg_pt_gp *tg_pt_gp;
1516         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1517
1518         if (alua->alua_type != SPC3_ALUA_EMULATED)
1519                 return;
1520
1521         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1522         if (!tg_pt_gp_mem)
1523                 return;
1524
1525         while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1526                 cpu_relax();
1527
1528         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1529         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1530         if (tg_pt_gp) {
1531                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1532                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1533                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1534                         tg_pt_gp->tg_pt_gp_members--;
1535                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1536                 }
1537                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1538                 tg_pt_gp_mem->tg_pt_gp = NULL;
1539         }
1540         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1541
1542         kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1543 }
1544
1545 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1546         struct se_subsystem_dev *su_dev,
1547         const char *name)
1548 {
1549         struct t10_alua_tg_pt_gp *tg_pt_gp;
1550         struct config_item *ci;
1551
1552         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1553         list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
1554                         tg_pt_gp_list) {
1555                 if (!tg_pt_gp->tg_pt_gp_valid_id)
1556                         continue;
1557                 ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1558                 if (!strcmp(config_item_name(ci), name)) {
1559                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1560                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1561                         return tg_pt_gp;
1562                 }
1563         }
1564         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1565
1566         return NULL;
1567 }
1568
1569 static void core_alua_put_tg_pt_gp_from_name(
1570         struct t10_alua_tg_pt_gp *tg_pt_gp)
1571 {
1572         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1573
1574         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1575         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1576         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1577 }
1578
1579 /*
1580  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1581  */
1582 void __core_alua_attach_tg_pt_gp_mem(
1583         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1584         struct t10_alua_tg_pt_gp *tg_pt_gp)
1585 {
1586         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1587         tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1588         tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1589         list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1590                         &tg_pt_gp->tg_pt_gp_mem_list);
1591         tg_pt_gp->tg_pt_gp_members++;
1592         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1593 }
1594
1595 /*
1596  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1597  */
1598 static void __core_alua_drop_tg_pt_gp_mem(
1599         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1600         struct t10_alua_tg_pt_gp *tg_pt_gp)
1601 {
1602         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1603         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1604         tg_pt_gp_mem->tg_pt_gp = NULL;
1605         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1606         tg_pt_gp->tg_pt_gp_members--;
1607         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1608 }
1609
1610 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1611 {
1612         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1613         struct config_item *tg_pt_ci;
1614         struct t10_alua *alua = &su_dev->t10_alua;
1615         struct t10_alua_tg_pt_gp *tg_pt_gp;
1616         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1617         ssize_t len = 0;
1618
1619         if (alua->alua_type != SPC3_ALUA_EMULATED)
1620                 return len;
1621
1622         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1623         if (!tg_pt_gp_mem)
1624                 return len;
1625
1626         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1627         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1628         if (tg_pt_gp) {
1629                 tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1630                 len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1631                         " %hu\nTG Port Primary Access State: %s\nTG Port "
1632                         "Primary Access Status: %s\nTG Port Secondary Access"
1633                         " State: %s\nTG Port Secondary Access Status: %s\n",
1634                         config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1635                         core_alua_dump_state(atomic_read(
1636                                         &tg_pt_gp->tg_pt_gp_alua_access_state)),
1637                         core_alua_dump_status(
1638                                 tg_pt_gp->tg_pt_gp_alua_access_status),
1639                         (atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1640                         "Offline" : "None",
1641                         core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1642         }
1643         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1644
1645         return len;
1646 }
1647
1648 ssize_t core_alua_store_tg_pt_gp_info(
1649         struct se_port *port,
1650         const char *page,
1651         size_t count)
1652 {
1653         struct se_portal_group *tpg;
1654         struct se_lun *lun;
1655         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1656         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1657         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1658         unsigned char buf[TG_PT_GROUP_NAME_BUF];
1659         int move = 0;
1660
1661         tpg = port->sep_tpg;
1662         lun = port->sep_lun;
1663
1664         if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
1665                 pr_warn("SPC3_ALUA_EMULATED not enabled for"
1666                         " %s/tpgt_%hu/%s\n", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1667                         tpg->se_tpg_tfo->tpg_get_tag(tpg),
1668                         config_item_name(&lun->lun_group.cg_item));
1669                 return -EINVAL;
1670         }
1671
1672         if (count > TG_PT_GROUP_NAME_BUF) {
1673                 pr_err("ALUA Target Port Group alias too large!\n");
1674                 return -EINVAL;
1675         }
1676         memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1677         memcpy(buf, page, count);
1678         /*
1679          * Any ALUA target port group alias besides "NULL" means we will be
1680          * making a new group association.
1681          */
1682         if (strcmp(strstrip(buf), "NULL")) {
1683                 /*
1684                  * core_alua_get_tg_pt_gp_by_name() will increment reference to
1685                  * struct t10_alua_tg_pt_gp.  This reference is released with
1686                  * core_alua_put_tg_pt_gp_from_name() below.
1687                  */
1688                 tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(su_dev,
1689                                         strstrip(buf));
1690                 if (!tg_pt_gp_new)
1691                         return -ENODEV;
1692         }
1693         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1694         if (!tg_pt_gp_mem) {
1695                 if (tg_pt_gp_new)
1696                         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1697                 pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
1698                 return -EINVAL;
1699         }
1700
1701         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1702         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1703         if (tg_pt_gp) {
1704                 /*
1705                  * Clearing an existing tg_pt_gp association, and replacing
1706                  * with the default_tg_pt_gp.
1707                  */
1708                 if (!tg_pt_gp_new) {
1709                         pr_debug("Target_Core_ConfigFS: Moving"
1710                                 " %s/tpgt_%hu/%s from ALUA Target Port Group:"
1711                                 " alua/%s, ID: %hu back to"
1712                                 " default_tg_pt_gp\n",
1713                                 tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1714                                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1715                                 config_item_name(&lun->lun_group.cg_item),
1716                                 config_item_name(
1717                                         &tg_pt_gp->tg_pt_gp_group.cg_item),
1718                                 tg_pt_gp->tg_pt_gp_id);
1719
1720                         __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1721                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1722                                         su_dev->t10_alua.default_tg_pt_gp);
1723                         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1724
1725                         return count;
1726                 }
1727                 /*
1728                  * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1729                  */
1730                 __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1731                 move = 1;
1732         }
1733         /*
1734          * Associate tg_pt_gp_mem with tg_pt_gp_new.
1735          */
1736         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1737         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1738         pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1739                 " Target Port Group: alua/%s, ID: %hu\n", (move) ?
1740                 "Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1741                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1742                 config_item_name(&lun->lun_group.cg_item),
1743                 config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1744                 tg_pt_gp_new->tg_pt_gp_id);
1745
1746         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1747         return count;
1748 }
1749
1750 ssize_t core_alua_show_access_type(
1751         struct t10_alua_tg_pt_gp *tg_pt_gp,
1752         char *page)
1753 {
1754         if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1755             (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1756                 return sprintf(page, "Implict and Explict\n");
1757         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1758                 return sprintf(page, "Implict\n");
1759         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1760                 return sprintf(page, "Explict\n");
1761         else
1762                 return sprintf(page, "None\n");
1763 }
1764
1765 ssize_t core_alua_store_access_type(
1766         struct t10_alua_tg_pt_gp *tg_pt_gp,
1767         const char *page,
1768         size_t count)
1769 {
1770         unsigned long tmp;
1771         int ret;
1772
1773         ret = strict_strtoul(page, 0, &tmp);
1774         if (ret < 0) {
1775                 pr_err("Unable to extract alua_access_type\n");
1776                 return -EINVAL;
1777         }
1778         if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1779                 pr_err("Illegal value for alua_access_type:"
1780                                 " %lu\n", tmp);
1781                 return -EINVAL;
1782         }
1783         if (tmp == 3)
1784                 tg_pt_gp->tg_pt_gp_alua_access_type =
1785                         TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1786         else if (tmp == 2)
1787                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1788         else if (tmp == 1)
1789                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1790         else
1791                 tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1792
1793         return count;
1794 }
1795
1796 ssize_t core_alua_show_nonop_delay_msecs(
1797         struct t10_alua_tg_pt_gp *tg_pt_gp,
1798         char *page)
1799 {
1800         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1801 }
1802
1803 ssize_t core_alua_store_nonop_delay_msecs(
1804         struct t10_alua_tg_pt_gp *tg_pt_gp,
1805         const char *page,
1806         size_t count)
1807 {
1808         unsigned long tmp;
1809         int ret;
1810
1811         ret = strict_strtoul(page, 0, &tmp);
1812         if (ret < 0) {
1813                 pr_err("Unable to extract nonop_delay_msecs\n");
1814                 return -EINVAL;
1815         }
1816         if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1817                 pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1818                         " ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1819                         ALUA_MAX_NONOP_DELAY_MSECS);
1820                 return -EINVAL;
1821         }
1822         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1823
1824         return count;
1825 }
1826
1827 ssize_t core_alua_show_trans_delay_msecs(
1828         struct t10_alua_tg_pt_gp *tg_pt_gp,
1829         char *page)
1830 {
1831         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1832 }
1833
1834 ssize_t core_alua_store_trans_delay_msecs(
1835         struct t10_alua_tg_pt_gp *tg_pt_gp,
1836         const char *page,
1837         size_t count)
1838 {
1839         unsigned long tmp;
1840         int ret;
1841
1842         ret = strict_strtoul(page, 0, &tmp);
1843         if (ret < 0) {
1844                 pr_err("Unable to extract trans_delay_msecs\n");
1845                 return -EINVAL;
1846         }
1847         if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1848                 pr_err("Passed trans_delay_msecs: %lu, exceeds"
1849                         " ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1850                         ALUA_MAX_TRANS_DELAY_MSECS);
1851                 return -EINVAL;
1852         }
1853         tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1854
1855         return count;
1856 }
1857
1858 ssize_t core_alua_show_preferred_bit(
1859         struct t10_alua_tg_pt_gp *tg_pt_gp,
1860         char *page)
1861 {
1862         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1863 }
1864
1865 ssize_t core_alua_store_preferred_bit(
1866         struct t10_alua_tg_pt_gp *tg_pt_gp,
1867         const char *page,
1868         size_t count)
1869 {
1870         unsigned long tmp;
1871         int ret;
1872
1873         ret = strict_strtoul(page, 0, &tmp);
1874         if (ret < 0) {
1875                 pr_err("Unable to extract preferred ALUA value\n");
1876                 return -EINVAL;
1877         }
1878         if ((tmp != 0) && (tmp != 1)) {
1879                 pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1880                 return -EINVAL;
1881         }
1882         tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1883
1884         return count;
1885 }
1886
1887 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1888 {
1889         if (!lun->lun_sep)
1890                 return -ENODEV;
1891
1892         return sprintf(page, "%d\n",
1893                 atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1894 }
1895
1896 ssize_t core_alua_store_offline_bit(
1897         struct se_lun *lun,
1898         const char *page,
1899         size_t count)
1900 {
1901         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1902         unsigned long tmp;
1903         int ret;
1904
1905         if (!lun->lun_sep)
1906                 return -ENODEV;
1907
1908         ret = strict_strtoul(page, 0, &tmp);
1909         if (ret < 0) {
1910                 pr_err("Unable to extract alua_tg_pt_offline value\n");
1911                 return -EINVAL;
1912         }
1913         if ((tmp != 0) && (tmp != 1)) {
1914                 pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1915                                 tmp);
1916                 return -EINVAL;
1917         }
1918         tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1919         if (!tg_pt_gp_mem) {
1920                 pr_err("Unable to locate *tg_pt_gp_mem\n");
1921                 return -EINVAL;
1922         }
1923
1924         ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1925                         lun->lun_sep, 0, (int)tmp);
1926         if (ret < 0)
1927                 return -EINVAL;
1928
1929         return count;
1930 }
1931
1932 ssize_t core_alua_show_secondary_status(
1933         struct se_lun *lun,
1934         char *page)
1935 {
1936         return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1937 }
1938
1939 ssize_t core_alua_store_secondary_status(
1940         struct se_lun *lun,
1941         const char *page,
1942         size_t count)
1943 {
1944         unsigned long tmp;
1945         int ret;
1946
1947         ret = strict_strtoul(page, 0, &tmp);
1948         if (ret < 0) {
1949                 pr_err("Unable to extract alua_tg_pt_status\n");
1950                 return -EINVAL;
1951         }
1952         if ((tmp != ALUA_STATUS_NONE) &&
1953             (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
1954             (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
1955                 pr_err("Illegal value for alua_tg_pt_status: %lu\n",
1956                                 tmp);
1957                 return -EINVAL;
1958         }
1959         lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
1960
1961         return count;
1962 }
1963
1964 ssize_t core_alua_show_secondary_write_metadata(
1965         struct se_lun *lun,
1966         char *page)
1967 {
1968         return sprintf(page, "%d\n",
1969                         lun->lun_sep->sep_tg_pt_secondary_write_md);
1970 }
1971
1972 ssize_t core_alua_store_secondary_write_metadata(
1973         struct se_lun *lun,
1974         const char *page,
1975         size_t count)
1976 {
1977         unsigned long tmp;
1978         int ret;
1979
1980         ret = strict_strtoul(page, 0, &tmp);
1981         if (ret < 0) {
1982                 pr_err("Unable to extract alua_tg_pt_write_md\n");
1983                 return -EINVAL;
1984         }
1985         if ((tmp != 0) && (tmp != 1)) {
1986                 pr_err("Illegal value for alua_tg_pt_write_md:"
1987                                 " %lu\n", tmp);
1988                 return -EINVAL;
1989         }
1990         lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
1991
1992         return count;
1993 }
1994
1995 int core_setup_alua(struct se_device *dev, int force_pt)
1996 {
1997         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1998         struct t10_alua *alua = &su_dev->t10_alua;
1999         struct t10_alua_lu_gp_member *lu_gp_mem;
2000         /*
2001          * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
2002          * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
2003          * cause a problem because libata and some SATA RAID HBAs appear
2004          * under Linux/SCSI, but emulate SCSI logic themselves.
2005          */
2006         if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
2007             !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
2008                 alua->alua_type = SPC_ALUA_PASSTHROUGH;
2009                 alua->alua_state_check = &core_alua_state_check_nop;
2010                 pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
2011                         " emulation\n", dev->transport->name);
2012                 return 0;
2013         }
2014         /*
2015          * If SPC-3 or above is reported by real or emulated struct se_device,
2016          * use emulated ALUA.
2017          */
2018         if (dev->transport->get_device_rev(dev) >= SCSI_3) {
2019                 pr_debug("%s: Enabling ALUA Emulation for SPC-3"
2020                         " device\n", dev->transport->name);
2021                 /*
2022                  * Associate this struct se_device with the default ALUA
2023                  * LUN Group.
2024                  */
2025                 lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2026                 if (IS_ERR(lu_gp_mem))
2027                         return PTR_ERR(lu_gp_mem);
2028
2029                 alua->alua_type = SPC3_ALUA_EMULATED;
2030                 alua->alua_state_check = &core_alua_state_check;
2031                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2032                 __core_alua_attach_lu_gp_mem(lu_gp_mem,
2033                                 default_lu_gp);
2034                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2035
2036                 pr_debug("%s: Adding to default ALUA LU Group:"
2037                         " core/alua/lu_gps/default_lu_gp\n",
2038                         dev->transport->name);
2039         } else {
2040                 alua->alua_type = SPC2_ALUA_DISABLED;
2041                 alua->alua_state_check = &core_alua_state_check_nop;
2042                 pr_debug("%s: Disabling ALUA Emulation for SPC-2"
2043                         " device\n", dev->transport->name);
2044         }
2045
2046         return 0;
2047 }