linux/drivers/target/target_core_alua.c
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   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
  44static int core_alua_check_transition(int state, int *primary);
  45static 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
  49static u16 alua_lu_gps_counter;
  50static u32 alua_lu_gps_count;
  51
  52static DEFINE_SPINLOCK(lu_gps_lock);
  53static LIST_HEAD(lu_gps_list);
  54
  55struct t10_alua_lu_gp *default_lu_gp;
  56
  57/*
  58 * REPORT_TARGET_PORT_GROUPS
  59 *
  60 * See spc4r17 section 6.27
  61 */
  62int target_emulate_report_target_port_groups(struct se_cmd *cmd)
  63{
  64        struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
  65        struct se_port *port;
  66        struct t10_alua_tg_pt_gp *tg_pt_gp;
  67        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
  68        unsigned char *buf;
  69        u32 rd_len = 0, off;
  70        int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
  71        /*
  72         * Skip over RESERVED area to first Target port group descriptor
  73         * depending on the PARAMETER DATA FORMAT type..
  74         */
  75        if (ext_hdr != 0)
  76                off = 8;
  77        else
  78                off = 4;
  79
  80        if (cmd->data_length < off) {
  81                pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
  82                        " small for %s header\n", cmd->data_length,
  83                        (ext_hdr) ? "extended" : "normal");
  84                cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
  85                return -EINVAL;
  86        }
  87        buf = transport_kmap_data_sg(cmd);
  88
  89        spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
  90        list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
  91                        tg_pt_gp_list) {
  92                /*
  93                 * Check if the Target port group and Target port descriptor list
  94                 * based on tg_pt_gp_members count will fit into the response payload.
  95                 * Otherwise, bump rd_len to let the initiator know we have exceeded
  96                 * the allocation length and the response is truncated.
  97                 */
  98                if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
  99                     cmd->data_length) {
 100                        rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
 101                        continue;
 102                }
 103                /*
 104                 * PREF: Preferred target port bit, determine if this
 105                 * bit should be set for port group.
 106                 */
 107                if (tg_pt_gp->tg_pt_gp_pref)
 108                        buf[off] = 0x80;
 109                /*
 110                 * Set the ASYMMETRIC ACCESS State
 111                 */
 112                buf[off++] |= (atomic_read(
 113                        &tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
 114                /*
 115                 * Set supported ASYMMETRIC ACCESS State bits
 116                 */
 117                buf[off] = 0x80; /* T_SUP */
 118                buf[off] |= 0x40; /* O_SUP */
 119                buf[off] |= 0x8; /* U_SUP */
 120                buf[off] |= 0x4; /* S_SUP */
 121                buf[off] |= 0x2; /* AN_SUP */
 122                buf[off++] |= 0x1; /* AO_SUP */
 123                /*
 124                 * TARGET PORT GROUP
 125                 */
 126                buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
 127                buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
 128
 129                off++; /* Skip over Reserved */
 130                /*
 131                 * STATUS CODE
 132                 */
 133                buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
 134                /*
 135                 * Vendor Specific field
 136                 */
 137                buf[off++] = 0x00;
 138                /*
 139                 * TARGET PORT COUNT
 140                 */
 141                buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
 142                rd_len += 8;
 143
 144                spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 145                list_for_each_entry(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
 146                                tg_pt_gp_mem_list) {
 147                        port = tg_pt_gp_mem->tg_pt;
 148                        /*
 149                         * Start Target Port descriptor format
 150                         *
 151                         * See spc4r17 section 6.2.7 Table 247
 152                         */
 153                        off += 2; /* Skip over Obsolete */
 154                        /*
 155                         * Set RELATIVE TARGET PORT IDENTIFIER
 156                         */
 157                        buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
 158                        buf[off++] = (port->sep_rtpi & 0xff);
 159                        rd_len += 4;
 160                }
 161                spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 162        }
 163        spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 164        /*
 165         * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 166         */
 167        put_unaligned_be32(rd_len, &buf[0]);
 168
 169        /*
 170         * Fill in the Extended header parameter data format if requested
 171         */
 172        if (ext_hdr != 0) {
 173                buf[4] = 0x10;
 174                /*
 175                 * Set the implict transition time (in seconds) for the application
 176                 * client to use as a base for it's transition timeout value.
 177                 *
 178                 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
 179                 * this CDB was received upon to determine this value individually
 180                 * for ALUA target port group.
 181                 */
 182                port = cmd->se_lun->lun_sep;
 183                tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 184                if (tg_pt_gp_mem) {
 185                        spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 186                        tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
 187                        if (tg_pt_gp)
 188                                buf[5] = tg_pt_gp->tg_pt_gp_implict_trans_secs;
 189                        spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 190                }
 191        }
 192        transport_kunmap_data_sg(cmd);
 193
 194        target_complete_cmd(cmd, GOOD);
 195        return 0;
 196}
 197
 198/*
 199 * SET_TARGET_PORT_GROUPS for explict ALUA operation.
 200 *
 201 * See spc4r17 section 6.35
 202 */
 203int target_emulate_set_target_port_groups(struct se_cmd *cmd)
 204{
 205        struct se_device *dev = cmd->se_dev;
 206        struct se_subsystem_dev *su_dev = dev->se_sub_dev;
 207        struct se_port *port, *l_port = cmd->se_lun->lun_sep;
 208        struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
 209        struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
 210        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
 211        unsigned char *buf;
 212        unsigned char *ptr;
 213        u32 len = 4; /* Skip over RESERVED area in header */
 214        int alua_access_state, primary = 0, rc;
 215        u16 tg_pt_id, rtpi;
 216
 217        if (!l_port) {
 218                cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 219                return -EINVAL;
 220        }
 221        if (cmd->data_length < 4) {
 222                pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
 223                        " small\n", cmd->data_length);
 224                cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 225                return -EINVAL;
 226        }
 227
 228        buf = transport_kmap_data_sg(cmd);
 229
 230        /*
 231         * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
 232         * for the local tg_pt_gp.
 233         */
 234        l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
 235        if (!l_tg_pt_gp_mem) {
 236                pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
 237                cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 238                rc = -EINVAL;
 239                goto out;
 240        }
 241        spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 242        l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
 243        if (!l_tg_pt_gp) {
 244                spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 245                pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
 246                cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 247                rc = -EINVAL;
 248                goto out;
 249        }
 250        rc = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
 251        spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 252
 253        if (!rc) {
 254                pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
 255                                " while TPGS_EXPLICT_ALUA is disabled\n");
 256                cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 257                rc = -EINVAL;
 258                goto out;
 259        }
 260
 261        ptr = &buf[4]; /* Skip over RESERVED area in header */
 262
 263        while (len < cmd->data_length) {
 264                alua_access_state = (ptr[0] & 0x0f);
 265                /*
 266                 * Check the received ALUA access state, and determine if
 267                 * the state is a primary or secondary target port asymmetric
 268                 * access state.
 269                 */
 270                rc = core_alua_check_transition(alua_access_state, &primary);
 271                if (rc != 0) {
 272                        /*
 273                         * If the SET TARGET PORT GROUPS attempts to establish
 274                         * an invalid combination of target port asymmetric
 275                         * access states or attempts to establish an
 276                         * unsupported target port asymmetric access state,
 277                         * then the command shall be terminated with CHECK
 278                         * CONDITION status, with the sense key set to ILLEGAL
 279                         * REQUEST, and the additional sense code set to INVALID
 280                         * FIELD IN PARAMETER LIST.
 281                         */
 282                        cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 283                        rc = -EINVAL;
 284                        goto out;
 285                }
 286                rc = -1;
 287                /*
 288                 * If the ASYMMETRIC ACCESS STATE field (see table 267)
 289                 * specifies a primary target port asymmetric access state,
 290                 * then the TARGET PORT GROUP OR TARGET PORT field specifies
 291                 * a primary target port group for which the primary target
 292                 * port asymmetric access state shall be changed. If the
 293                 * ASYMMETRIC ACCESS STATE field specifies a secondary target
 294                 * port asymmetric access state, then the TARGET PORT GROUP OR
 295                 * TARGET PORT field specifies the relative target port
 296                 * identifier (see 3.1.120) of the target port for which the
 297                 * secondary target port asymmetric access state shall be
 298                 * changed.
 299                 */
 300                if (primary) {
 301                        tg_pt_id = get_unaligned_be16(ptr + 2);
 302                        /*
 303                         * Locate the matching target port group ID from
 304                         * the global tg_pt_gp list
 305                         */
 306                        spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 307                        list_for_each_entry(tg_pt_gp,
 308                                        &su_dev->t10_alua.tg_pt_gps_list,
 309                                        tg_pt_gp_list) {
 310                                if (!tg_pt_gp->tg_pt_gp_valid_id)
 311                                        continue;
 312
 313                                if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
 314                                        continue;
 315
 316                                atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 317                                smp_mb__after_atomic_inc();
 318                                spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 319
 320                                rc = core_alua_do_port_transition(tg_pt_gp,
 321                                                dev, l_port, nacl,
 322                                                alua_access_state, 1);
 323
 324                                spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 325                                atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
 326                                smp_mb__after_atomic_dec();
 327                                break;
 328                        }
 329                        spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 330                        /*
 331                         * If not matching target port group ID can be located
 332                         * throw an exception with ASCQ: INVALID_PARAMETER_LIST
 333                         */
 334                        if (rc != 0) {
 335                                cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 336                                rc = -EINVAL;
 337                                goto out;
 338                        }
 339                } else {
 340                        /*
 341                         * Extact the RELATIVE TARGET PORT IDENTIFIER to identify
 342                         * the Target Port in question for the the incoming
 343                         * SET_TARGET_PORT_GROUPS op.
 344                         */
 345                        rtpi = get_unaligned_be16(ptr + 2);
 346                        /*
 347                         * Locate the matching relative target port identifier
 348                         * for the struct se_device storage object.
 349                         */
 350                        spin_lock(&dev->se_port_lock);
 351                        list_for_each_entry(port, &dev->dev_sep_list,
 352                                                        sep_list) {
 353                                if (port->sep_rtpi != rtpi)
 354                                        continue;
 355
 356                                tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 357                                spin_unlock(&dev->se_port_lock);
 358
 359                                rc = core_alua_set_tg_pt_secondary_state(
 360                                                tg_pt_gp_mem, port, 1, 1);
 361
 362                                spin_lock(&dev->se_port_lock);
 363                                break;
 364                        }
 365                        spin_unlock(&dev->se_port_lock);
 366                        /*
 367                         * If not matching relative target port identifier can
 368                         * be located, throw an exception with ASCQ:
 369                         * INVALID_PARAMETER_LIST
 370                         */
 371                        if (rc != 0) {
 372                                cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 373                                rc = -EINVAL;
 374                                goto out;
 375                        }
 376                }
 377
 378                ptr += 4;
 379                len += 4;
 380        }
 381
 382out:
 383        transport_kunmap_data_sg(cmd);
 384        if (!rc)
 385                target_complete_cmd(cmd, GOOD);
 386        return rc;
 387}
 388
 389static inline int core_alua_state_nonoptimized(
 390        struct se_cmd *cmd,
 391        unsigned char *cdb,
 392        int nonop_delay_msecs,
 393        u8 *alua_ascq)
 394{
 395        /*
 396         * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
 397         * later to determine if processing of this cmd needs to be
 398         * temporarily delayed for the Active/NonOptimized primary access state.
 399         */
 400        cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
 401        cmd->alua_nonop_delay = nonop_delay_msecs;
 402        return 0;
 403}
 404
 405static inline int core_alua_state_standby(
 406        struct se_cmd *cmd,
 407        unsigned char *cdb,
 408        u8 *alua_ascq)
 409{
 410        /*
 411         * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
 412         * spc4r17 section 5.9.2.4.4
 413         */
 414        switch (cdb[0]) {
 415        case INQUIRY:
 416        case LOG_SELECT:
 417        case LOG_SENSE:
 418        case MODE_SELECT:
 419        case MODE_SENSE:
 420        case REPORT_LUNS:
 421        case RECEIVE_DIAGNOSTIC:
 422        case SEND_DIAGNOSTIC:
 423        case MAINTENANCE_IN:
 424                switch (cdb[1] & 0x1f) {
 425                case MI_REPORT_TARGET_PGS:
 426                        return 0;
 427                default:
 428                        *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 429                        return 1;
 430                }
 431        case MAINTENANCE_OUT:
 432                switch (cdb[1]) {
 433                case MO_SET_TARGET_PGS:
 434                        return 0;
 435                default:
 436                        *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 437                        return 1;
 438                }
 439        case REQUEST_SENSE:
 440        case PERSISTENT_RESERVE_IN:
 441        case PERSISTENT_RESERVE_OUT:
 442        case READ_BUFFER:
 443        case WRITE_BUFFER:
 444                return 0;
 445        default:
 446                *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 447                return 1;
 448        }
 449
 450        return 0;
 451}
 452
 453static inline int core_alua_state_unavailable(
 454        struct se_cmd *cmd,
 455        unsigned char *cdb,
 456        u8 *alua_ascq)
 457{
 458        /*
 459         * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
 460         * spc4r17 section 5.9.2.4.5
 461         */
 462        switch (cdb[0]) {
 463        case INQUIRY:
 464        case REPORT_LUNS:
 465        case MAINTENANCE_IN:
 466                switch (cdb[1] & 0x1f) {
 467                case MI_REPORT_TARGET_PGS:
 468                        return 0;
 469                default:
 470                        *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 471                        return 1;
 472                }
 473        case MAINTENANCE_OUT:
 474                switch (cdb[1]) {
 475                case MO_SET_TARGET_PGS:
 476                        return 0;
 477                default:
 478                        *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 479                        return 1;
 480                }
 481        case REQUEST_SENSE:
 482        case READ_BUFFER:
 483        case WRITE_BUFFER:
 484                return 0;
 485        default:
 486                *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 487                return 1;
 488        }
 489
 490        return 0;
 491}
 492
 493static inline int core_alua_state_transition(
 494        struct se_cmd *cmd,
 495        unsigned char *cdb,
 496        u8 *alua_ascq)
 497{
 498        /*
 499         * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
 500         * spc4r17 section 5.9.2.5
 501         */
 502        switch (cdb[0]) {
 503        case INQUIRY:
 504        case REPORT_LUNS:
 505        case MAINTENANCE_IN:
 506                switch (cdb[1] & 0x1f) {
 507                case MI_REPORT_TARGET_PGS:
 508                        return 0;
 509                default:
 510                        *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 511                        return 1;
 512                }
 513        case REQUEST_SENSE:
 514        case READ_BUFFER:
 515        case WRITE_BUFFER:
 516                return 0;
 517        default:
 518                *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 519                return 1;
 520        }
 521
 522        return 0;
 523}
 524
 525/*
 526 * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
 527 * in transport_cmd_sequencer().  This function is assigned to
 528 * struct t10_alua *->state_check() in core_setup_alua()
 529 */
 530static int core_alua_state_check_nop(
 531        struct se_cmd *cmd,
 532        unsigned char *cdb,
 533        u8 *alua_ascq)
 534{
 535        return 0;
 536}
 537
 538/*
 539 * Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
 540 * This function is assigned to struct t10_alua *->state_check() in
 541 * core_setup_alua()
 542 *
 543 * Also, this function can return three different return codes to
 544 * signal transport_generic_cmd_sequencer()
 545 *
 546 * return 1: Is used to signal LUN not accecsable, and check condition/not ready
 547 * return 0: Used to signal success
 548 * reutrn -1: Used to signal failure, and invalid cdb field
 549 */
 550static int core_alua_state_check(
 551        struct se_cmd *cmd,
 552        unsigned char *cdb,
 553        u8 *alua_ascq)
 554{
 555        struct se_lun *lun = cmd->se_lun;
 556        struct se_port *port = lun->lun_sep;
 557        struct t10_alua_tg_pt_gp *tg_pt_gp;
 558        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
 559        int out_alua_state, nonop_delay_msecs;
 560
 561        if (!port)
 562                return 0;
 563        /*
 564         * First, check for a struct se_port specific secondary ALUA target port
 565         * access state: OFFLINE
 566         */
 567        if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
 568                *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 569                pr_debug("ALUA: Got secondary offline status for local"
 570                                " target port\n");
 571                *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 572                return 1;
 573        }
 574         /*
 575         * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
 576         * ALUA target port group, to obtain current ALUA access state.
 577         * Otherwise look for the underlying struct se_device association with
 578         * a ALUA logical unit group.
 579         */
 580        tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 581        spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 582        tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
 583        out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 584        nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
 585        spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 586        /*
 587         * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a separate conditional
 588         * statement so the compiler knows explicitly to check this case first.
 589         * For the Optimized ALUA access state case, we want to process the
 590         * incoming fabric cmd ASAP..
 591         */
 592        if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
 593                return 0;
 594
 595        switch (out_alua_state) {
 596        case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 597                return core_alua_state_nonoptimized(cmd, cdb,
 598                                        nonop_delay_msecs, alua_ascq);
 599        case ALUA_ACCESS_STATE_STANDBY:
 600                return core_alua_state_standby(cmd, cdb, alua_ascq);
 601        case ALUA_ACCESS_STATE_UNAVAILABLE:
 602                return core_alua_state_unavailable(cmd, cdb, alua_ascq);
 603        case ALUA_ACCESS_STATE_TRANSITION:
 604                return core_alua_state_transition(cmd, cdb, alua_ascq);
 605        /*
 606         * OFFLINE is a secondary ALUA target port group access state, that is
 607         * handled above with struct se_port->sep_tg_pt_secondary_offline=1
 608         */
 609        case ALUA_ACCESS_STATE_OFFLINE:
 610        default:
 611                pr_err("Unknown ALUA access state: 0x%02x\n",
 612                                out_alua_state);
 613                return -EINVAL;
 614        }
 615
 616        return 0;
 617}
 618
 619/*
 620 * Check implict and explict ALUA state change request.
 621 */
 622static int core_alua_check_transition(int state, int *primary)
 623{
 624        switch (state) {
 625        case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 626        case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 627        case ALUA_ACCESS_STATE_STANDBY:
 628        case ALUA_ACCESS_STATE_UNAVAILABLE:
 629                /*
 630                 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
 631                 * defined as primary target port asymmetric access states.
 632                 */
 633                *primary = 1;
 634                break;
 635        case ALUA_ACCESS_STATE_OFFLINE:
 636                /*
 637                 * OFFLINE state is defined as a secondary target port
 638                 * asymmetric access state.
 639                 */
 640                *primary = 0;
 641                break;
 642        default:
 643                pr_err("Unknown ALUA access state: 0x%02x\n", state);
 644                return -EINVAL;
 645        }
 646
 647        return 0;
 648}
 649
 650static char *core_alua_dump_state(int state)
 651{
 652        switch (state) {
 653        case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 654                return "Active/Optimized";
 655        case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 656                return "Active/NonOptimized";
 657        case ALUA_ACCESS_STATE_STANDBY:
 658                return "Standby";
 659        case ALUA_ACCESS_STATE_UNAVAILABLE:
 660                return "Unavailable";
 661        case ALUA_ACCESS_STATE_OFFLINE:
 662                return "Offline";
 663        default:
 664                return "Unknown";
 665        }
 666
 667        return NULL;
 668}
 669
 670char *core_alua_dump_status(int status)
 671{
 672        switch (status) {
 673        case ALUA_STATUS_NONE:
 674                return "None";
 675        case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
 676                return "Altered by Explict STPG";
 677        case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
 678                return "Altered by Implict ALUA";
 679        default:
 680                return "Unknown";
 681        }
 682
 683        return NULL;
 684}
 685
 686/*
 687 * Used by fabric modules to determine when we need to delay processing
 688 * for the Active/NonOptimized paths..
 689 */
 690int core_alua_check_nonop_delay(
 691        struct se_cmd *cmd)
 692{
 693        if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
 694                return 0;
 695        if (in_interrupt())
 696                return 0;
 697        /*
 698         * The ALUA Active/NonOptimized access state delay can be disabled
 699         * in via configfs with a value of zero
 700         */
 701        if (!cmd->alua_nonop_delay)
 702                return 0;
 703        /*
 704         * struct se_cmd->alua_nonop_delay gets set by a target port group
 705         * defined interval in core_alua_state_nonoptimized()
 706         */
 707        msleep_interruptible(cmd->alua_nonop_delay);
 708        return 0;
 709}
 710EXPORT_SYMBOL(core_alua_check_nonop_delay);
 711
 712/*
 713 * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
 714 *
 715 */
 716static int core_alua_write_tpg_metadata(
 717        const char *path,
 718        unsigned char *md_buf,
 719        u32 md_buf_len)
 720{
 721        mm_segment_t old_fs;
 722        struct file *file;
 723        struct iovec iov[1];
 724        int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
 725
 726        memset(iov, 0, sizeof(struct iovec));
 727
 728        file = filp_open(path, flags, 0600);
 729        if (IS_ERR(file) || !file || !file->f_dentry) {
 730                pr_err("filp_open(%s) for ALUA metadata failed\n",
 731                        path);
 732                return -ENODEV;
 733        }
 734
 735        iov[0].iov_base = &md_buf[0];
 736        iov[0].iov_len = md_buf_len;
 737
 738        old_fs = get_fs();
 739        set_fs(get_ds());
 740        ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
 741        set_fs(old_fs);
 742
 743        if (ret < 0) {
 744                pr_err("Error writing ALUA metadata file: %s\n", path);
 745                filp_close(file, NULL);
 746                return -EIO;
 747        }
 748        filp_close(file, NULL);
 749
 750        return 0;
 751}
 752
 753/*
 754 * Called with tg_pt_gp->tg_pt_gp_md_mutex held
 755 */
 756static int core_alua_update_tpg_primary_metadata(
 757        struct t10_alua_tg_pt_gp *tg_pt_gp,
 758        int primary_state,
 759        unsigned char *md_buf)
 760{
 761        struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
 762        struct t10_wwn *wwn = &su_dev->t10_wwn;
 763        char path[ALUA_METADATA_PATH_LEN];
 764        int len;
 765
 766        memset(path, 0, ALUA_METADATA_PATH_LEN);
 767
 768        len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
 769                        "tg_pt_gp_id=%hu\n"
 770                        "alua_access_state=0x%02x\n"
 771                        "alua_access_status=0x%02x\n",
 772                        tg_pt_gp->tg_pt_gp_id, primary_state,
 773                        tg_pt_gp->tg_pt_gp_alua_access_status);
 774
 775        snprintf(path, ALUA_METADATA_PATH_LEN,
 776                "/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
 777                config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 778
 779        return core_alua_write_tpg_metadata(path, md_buf, len);
 780}
 781
 782static int core_alua_do_transition_tg_pt(
 783        struct t10_alua_tg_pt_gp *tg_pt_gp,
 784        struct se_port *l_port,
 785        struct se_node_acl *nacl,
 786        unsigned char *md_buf,
 787        int new_state,
 788        int explict)
 789{
 790        struct se_dev_entry *se_deve;
 791        struct se_lun_acl *lacl;
 792        struct se_port *port;
 793        struct t10_alua_tg_pt_gp_member *mem;
 794        int old_state = 0;
 795        /*
 796         * Save the old primary ALUA access state, and set the current state
 797         * to ALUA_ACCESS_STATE_TRANSITION.
 798         */
 799        old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 800        atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
 801                        ALUA_ACCESS_STATE_TRANSITION);
 802        tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
 803                                ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
 804                                ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
 805        /*
 806         * Check for the optional ALUA primary state transition delay
 807         */
 808        if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
 809                msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
 810
 811        spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 812        list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
 813                                tg_pt_gp_mem_list) {
 814                port = mem->tg_pt;
 815                /*
 816                 * After an implicit target port asymmetric access state
 817                 * change, a device server shall establish a unit attention
 818                 * condition for the initiator port associated with every I_T
 819                 * nexus with the additional sense code set to ASYMMETRIC
 820                 * ACCESS STATE CHAGED.
 821                 *
 822                 * After an explicit target port asymmetric access state
 823                 * change, a device server shall establish a unit attention
 824                 * condition with the additional sense code set to ASYMMETRIC
 825                 * ACCESS STATE CHANGED for the initiator port associated with
 826                 * every I_T nexus other than the I_T nexus on which the SET
 827                 * TARGET PORT GROUPS command
 828                 */
 829                atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
 830                smp_mb__after_atomic_inc();
 831                spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 832
 833                spin_lock_bh(&port->sep_alua_lock);
 834                list_for_each_entry(se_deve, &port->sep_alua_list,
 835                                        alua_port_list) {
 836                        lacl = se_deve->se_lun_acl;
 837                        /*
 838                         * se_deve->se_lun_acl pointer may be NULL for a
 839                         * entry created without explict Node+MappedLUN ACLs
 840                         */
 841                        if (!lacl)
 842                                continue;
 843
 844                        if (explict &&
 845                           (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
 846                           (l_port != NULL) && (l_port == port))
 847                                continue;
 848
 849                        core_scsi3_ua_allocate(lacl->se_lun_nacl,
 850                                se_deve->mapped_lun, 0x2A,
 851                                ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
 852                }
 853                spin_unlock_bh(&port->sep_alua_lock);
 854
 855                spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 856                atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
 857                smp_mb__after_atomic_dec();
 858        }
 859        spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 860        /*
 861         * Update the ALUA metadata buf that has been allocated in
 862         * core_alua_do_port_transition(), this metadata will be written
 863         * to struct file.
 864         *
 865         * Note that there is the case where we do not want to update the
 866         * metadata when the saved metadata is being parsed in userspace
 867         * when setting the existing port access state and access status.
 868         *
 869         * Also note that the failure to write out the ALUA metadata to
 870         * struct file does NOT affect the actual ALUA transition.
 871         */
 872        if (tg_pt_gp->tg_pt_gp_write_metadata) {
 873                mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
 874                core_alua_update_tpg_primary_metadata(tg_pt_gp,
 875                                        new_state, md_buf);
 876                mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
 877        }
 878        /*
 879         * Set the current primary ALUA access state to the requested new state
 880         */
 881        atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
 882
 883        pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
 884                " from primary access state %s to %s\n", (explict) ? "explict" :
 885                "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
 886                tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
 887                core_alua_dump_state(new_state));
 888
 889        return 0;
 890}
 891
 892int core_alua_do_port_transition(
 893        struct t10_alua_tg_pt_gp *l_tg_pt_gp,
 894        struct se_device *l_dev,
 895        struct se_port *l_port,
 896        struct se_node_acl *l_nacl,
 897        int new_state,
 898        int explict)
 899{
 900        struct se_device *dev;
 901        struct se_port *port;
 902        struct se_subsystem_dev *su_dev;
 903        struct se_node_acl *nacl;
 904        struct t10_alua_lu_gp *lu_gp;
 905        struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
 906        struct t10_alua_tg_pt_gp *tg_pt_gp;
 907        unsigned char *md_buf;
 908        int primary;
 909
 910        if (core_alua_check_transition(new_state, &primary) != 0)
 911                return -EINVAL;
 912
 913        md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
 914        if (!md_buf) {
 915                pr_err("Unable to allocate buf for ALUA metadata\n");
 916                return -ENOMEM;
 917        }
 918
 919        local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
 920        spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
 921        lu_gp = local_lu_gp_mem->lu_gp;
 922        atomic_inc(&lu_gp->lu_gp_ref_cnt);
 923        smp_mb__after_atomic_inc();
 924        spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
 925        /*
 926         * For storage objects that are members of the 'default_lu_gp',
 927         * we only do transition on the passed *l_tp_pt_gp, and not
 928         * on all of the matching target port groups IDs in default_lu_gp.
 929         */
 930        if (!lu_gp->lu_gp_id) {
 931                /*
 932                 * core_alua_do_transition_tg_pt() will always return
 933                 * success.
 934                 */
 935                core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
 936                                        md_buf, new_state, explict);
 937                atomic_dec(&lu_gp->lu_gp_ref_cnt);
 938                smp_mb__after_atomic_dec();
 939                kfree(md_buf);
 940                return 0;
 941        }
 942        /*
 943         * For all other LU groups aside from 'default_lu_gp', walk all of
 944         * the associated storage objects looking for a matching target port
 945         * group ID from the local target port group.
 946         */
 947        spin_lock(&lu_gp->lu_gp_lock);
 948        list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
 949                                lu_gp_mem_list) {
 950
 951                dev = lu_gp_mem->lu_gp_mem_dev;
 952                su_dev = dev->se_sub_dev;
 953                atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
 954                smp_mb__after_atomic_inc();
 955                spin_unlock(&lu_gp->lu_gp_lock);
 956
 957                spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 958                list_for_each_entry(tg_pt_gp,
 959                                &su_dev->t10_alua.tg_pt_gps_list,
 960                                tg_pt_gp_list) {
 961
 962                        if (!tg_pt_gp->tg_pt_gp_valid_id)
 963                                continue;
 964                        /*
 965                         * If the target behavior port asymmetric access state
 966                         * is changed for any target port group accessiable via
 967                         * a logical unit within a LU group, the target port
 968                         * behavior group asymmetric access states for the same
 969                         * target port group accessible via other logical units
 970                         * in that LU group will also change.
 971                         */
 972                        if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
 973                                continue;
 974
 975                        if (l_tg_pt_gp == tg_pt_gp) {
 976                                port = l_port;
 977                                nacl = l_nacl;
 978                        } else {
 979                                port = NULL;
 980                                nacl = NULL;
 981                        }
 982                        atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 983                        smp_mb__after_atomic_inc();
 984                        spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 985                        /*
 986                         * core_alua_do_transition_tg_pt() will always return
 987                         * success.
 988                         */
 989                        core_alua_do_transition_tg_pt(tg_pt_gp, port,
 990                                        nacl, md_buf, new_state, explict);
 991
 992                        spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 993                        atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
 994                        smp_mb__after_atomic_dec();
 995                }
 996                spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 997
 998                spin_lock(&lu_gp->lu_gp_lock);
 999                atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
1000                smp_mb__after_atomic_dec();
1001        }
1002        spin_unlock(&lu_gp->lu_gp_lock);
1003
1004        pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1005                " Group IDs: %hu %s transition to primary state: %s\n",
1006                config_item_name(&lu_gp->lu_gp_group.cg_item),
1007                l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
1008                core_alua_dump_state(new_state));
1009
1010        atomic_dec(&lu_gp->lu_gp_ref_cnt);
1011        smp_mb__after_atomic_dec();
1012        kfree(md_buf);
1013        return 0;
1014}
1015
1016/*
1017 * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
1018 */
1019static int core_alua_update_tpg_secondary_metadata(
1020        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1021        struct se_port *port,
1022        unsigned char *md_buf,
1023        u32 md_buf_len)
1024{
1025        struct se_portal_group *se_tpg = port->sep_tpg;
1026        char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
1027        int len;
1028
1029        memset(path, 0, ALUA_METADATA_PATH_LEN);
1030        memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1031
1032        len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1033                        se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1034
1035        if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1036                snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1037                                se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1038
1039        len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1040                        "alua_tg_pt_status=0x%02x\n",
1041                        atomic_read(&port->sep_tg_pt_secondary_offline),
1042                        port->sep_tg_pt_secondary_stat);
1043
1044        snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1045                        se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1046                        port->sep_lun->unpacked_lun);
1047
1048        return core_alua_write_tpg_metadata(path, md_buf, len);
1049}
1050
1051static int core_alua_set_tg_pt_secondary_state(
1052        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1053        struct se_port *port,
1054        int explict,
1055        int offline)
1056{
1057        struct t10_alua_tg_pt_gp *tg_pt_gp;
1058        unsigned char *md_buf;
1059        u32 md_buf_len;
1060        int trans_delay_msecs;
1061
1062        spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1063        tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1064        if (!tg_pt_gp) {
1065                spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1066                pr_err("Unable to complete secondary state"
1067                                " transition\n");
1068                return -EINVAL;
1069        }
1070        trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1071        /*
1072         * Set the secondary ALUA target port access state to OFFLINE
1073         * or release the previously secondary state for struct se_port
1074         */
1075        if (offline)
1076                atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1077        else
1078                atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1079
1080        md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1081        port->sep_tg_pt_secondary_stat = (explict) ?
1082                        ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
1083                        ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
1084
1085        pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1086                " to secondary access state: %s\n", (explict) ? "explict" :
1087                "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1088                tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1089
1090        spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1091        /*
1092         * Do the optional transition delay after we set the secondary
1093         * ALUA access state.
1094         */
1095        if (trans_delay_msecs != 0)
1096                msleep_interruptible(trans_delay_msecs);
1097        /*
1098         * See if we need to update the ALUA fabric port metadata for
1099         * secondary state and status
1100         */
1101        if (port->sep_tg_pt_secondary_write_md) {
1102                md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1103                if (!md_buf) {
1104                        pr_err("Unable to allocate md_buf for"
1105                                " secondary ALUA access metadata\n");
1106                        return -ENOMEM;
1107                }
1108                mutex_lock(&port->sep_tg_pt_md_mutex);
1109                core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1110                                md_buf, md_buf_len);
1111                mutex_unlock(&port->sep_tg_pt_md_mutex);
1112
1113                kfree(md_buf);
1114        }
1115
1116        return 0;
1117}
1118
1119struct t10_alua_lu_gp *
1120core_alua_allocate_lu_gp(const char *name, int def_group)
1121{
1122        struct t10_alua_lu_gp *lu_gp;
1123
1124        lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1125        if (!lu_gp) {
1126                pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1127                return ERR_PTR(-ENOMEM);
1128        }
1129        INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1130        INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1131        spin_lock_init(&lu_gp->lu_gp_lock);
1132        atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1133
1134        if (def_group) {
1135                lu_gp->lu_gp_id = alua_lu_gps_counter++;
1136                lu_gp->lu_gp_valid_id = 1;
1137                alua_lu_gps_count++;
1138        }
1139
1140        return lu_gp;
1141}
1142
1143int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1144{
1145        struct t10_alua_lu_gp *lu_gp_tmp;
1146        u16 lu_gp_id_tmp;
1147        /*
1148         * The lu_gp->lu_gp_id may only be set once..
1149         */
1150        if (lu_gp->lu_gp_valid_id) {
1151                pr_warn("ALUA LU Group already has a valid ID,"
1152                        " ignoring request\n");
1153                return -EINVAL;
1154        }
1155
1156        spin_lock(&lu_gps_lock);
1157        if (alua_lu_gps_count == 0x0000ffff) {
1158                pr_err("Maximum ALUA alua_lu_gps_count:"
1159                                " 0x0000ffff reached\n");
1160                spin_unlock(&lu_gps_lock);
1161                kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1162                return -ENOSPC;
1163        }
1164again:
1165        lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1166                                alua_lu_gps_counter++;
1167
1168        list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1169                if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1170                        if (!lu_gp_id)
1171                                goto again;
1172
1173                        pr_warn("ALUA Logical Unit Group ID: %hu"
1174                                " already exists, ignoring request\n",
1175                                lu_gp_id);
1176                        spin_unlock(&lu_gps_lock);
1177                        return -EINVAL;
1178                }
1179        }
1180
1181        lu_gp->lu_gp_id = lu_gp_id_tmp;
1182        lu_gp->lu_gp_valid_id = 1;
1183        list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1184        alua_lu_gps_count++;
1185        spin_unlock(&lu_gps_lock);
1186
1187        return 0;
1188}
1189
1190static struct t10_alua_lu_gp_member *
1191core_alua_allocate_lu_gp_mem(struct se_device *dev)
1192{
1193        struct t10_alua_lu_gp_member *lu_gp_mem;
1194
1195        lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1196        if (!lu_gp_mem) {
1197                pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1198                return ERR_PTR(-ENOMEM);
1199        }
1200        INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1201        spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1202        atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1203
1204        lu_gp_mem->lu_gp_mem_dev = dev;
1205        dev->dev_alua_lu_gp_mem = lu_gp_mem;
1206
1207        return lu_gp_mem;
1208}
1209
1210void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1211{
1212        struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1213        /*
1214         * Once we have reached this point, config_item_put() has
1215         * already been called from target_core_alua_drop_lu_gp().
1216         *
1217         * Here, we remove the *lu_gp from the global list so that
1218         * no associations can be made while we are releasing
1219         * struct t10_alua_lu_gp.
1220         */
1221        spin_lock(&lu_gps_lock);
1222        list_del(&lu_gp->lu_gp_node);
1223        alua_lu_gps_count--;
1224        spin_unlock(&lu_gps_lock);
1225        /*
1226         * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1227         * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1228         * released with core_alua_put_lu_gp_from_name()
1229         */
1230        while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1231                cpu_relax();
1232        /*
1233         * Release reference to struct t10_alua_lu_gp * from all associated
1234         * struct se_device.
1235         */
1236        spin_lock(&lu_gp->lu_gp_lock);
1237        list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1238                                &lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1239                if (lu_gp_mem->lu_gp_assoc) {
1240                        list_del(&lu_gp_mem->lu_gp_mem_list);
1241                        lu_gp->lu_gp_members--;
1242                        lu_gp_mem->lu_gp_assoc = 0;
1243                }
1244                spin_unlock(&lu_gp->lu_gp_lock);
1245                /*
1246                 *
1247                 * lu_gp_mem is associated with a single
1248                 * struct se_device->dev_alua_lu_gp_mem, and is released when
1249                 * struct se_device is released via core_alua_free_lu_gp_mem().
1250                 *
1251                 * If the passed lu_gp does NOT match the default_lu_gp, assume
1252                 * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1253                 */
1254                spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1255                if (lu_gp != default_lu_gp)
1256                        __core_alua_attach_lu_gp_mem(lu_gp_mem,
1257                                        default_lu_gp);
1258                else
1259                        lu_gp_mem->lu_gp = NULL;
1260                spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1261
1262                spin_lock(&lu_gp->lu_gp_lock);
1263        }
1264        spin_unlock(&lu_gp->lu_gp_lock);
1265
1266        kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1267}
1268
1269void core_alua_free_lu_gp_mem(struct se_device *dev)
1270{
1271        struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1272        struct t10_alua *alua = &su_dev->t10_alua;
1273        struct t10_alua_lu_gp *lu_gp;
1274        struct t10_alua_lu_gp_member *lu_gp_mem;
1275
1276        if (alua->alua_type != SPC3_ALUA_EMULATED)
1277                return;
1278
1279        lu_gp_mem = dev->dev_alua_lu_gp_mem;
1280        if (!lu_gp_mem)
1281                return;
1282
1283        while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1284                cpu_relax();
1285
1286        spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1287        lu_gp = lu_gp_mem->lu_gp;
1288        if (lu_gp) {
1289                spin_lock(&lu_gp->lu_gp_lock);
1290                if (lu_gp_mem->lu_gp_assoc) {
1291                        list_del(&lu_gp_mem->lu_gp_mem_list);
1292                        lu_gp->lu_gp_members--;
1293                        lu_gp_mem->lu_gp_assoc = 0;
1294                }
1295                spin_unlock(&lu_gp->lu_gp_lock);
1296                lu_gp_mem->lu_gp = NULL;
1297        }
1298        spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1299
1300        kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1301}
1302
1303struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1304{
1305        struct t10_alua_lu_gp *lu_gp;
1306        struct config_item *ci;
1307
1308        spin_lock(&lu_gps_lock);
1309        list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1310                if (!lu_gp->lu_gp_valid_id)
1311                        continue;
1312                ci = &lu_gp->lu_gp_group.cg_item;
1313                if (!strcmp(config_item_name(ci), name)) {
1314                        atomic_inc(&lu_gp->lu_gp_ref_cnt);
1315                        spin_unlock(&lu_gps_lock);
1316                        return lu_gp;
1317                }
1318        }
1319        spin_unlock(&lu_gps_lock);
1320
1321        return NULL;
1322}
1323
1324void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1325{
1326        spin_lock(&lu_gps_lock);
1327        atomic_dec(&lu_gp->lu_gp_ref_cnt);
1328        spin_unlock(&lu_gps_lock);
1329}
1330
1331/*
1332 * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1333 */
1334void __core_alua_attach_lu_gp_mem(
1335        struct t10_alua_lu_gp_member *lu_gp_mem,
1336        struct t10_alua_lu_gp *lu_gp)
1337{
1338        spin_lock(&lu_gp->lu_gp_lock);
1339        lu_gp_mem->lu_gp = lu_gp;
1340        lu_gp_mem->lu_gp_assoc = 1;
1341        list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1342        lu_gp->lu_gp_members++;
1343        spin_unlock(&lu_gp->lu_gp_lock);
1344}
1345
1346/*
1347 * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1348 */
1349void __core_alua_drop_lu_gp_mem(
1350        struct t10_alua_lu_gp_member *lu_gp_mem,
1351        struct t10_alua_lu_gp *lu_gp)
1352{
1353        spin_lock(&lu_gp->lu_gp_lock);
1354        list_del(&lu_gp_mem->lu_gp_mem_list);
1355        lu_gp_mem->lu_gp = NULL;
1356        lu_gp_mem->lu_gp_assoc = 0;
1357        lu_gp->lu_gp_members--;
1358        spin_unlock(&lu_gp->lu_gp_lock);
1359}
1360
1361struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
1362        struct se_subsystem_dev *su_dev,
1363        const char *name,
1364        int def_group)
1365{
1366        struct t10_alua_tg_pt_gp *tg_pt_gp;
1367
1368        tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1369        if (!tg_pt_gp) {
1370                pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1371                return NULL;
1372        }
1373        INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1374        INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1375        mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1376        spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1377        atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1378        tg_pt_gp->tg_pt_gp_su_dev = su_dev;
1379        tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1380        atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1381                ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1382        /*
1383         * Enable both explict and implict ALUA support by default
1384         */
1385        tg_pt_gp->tg_pt_gp_alua_access_type =
1386                        TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1387        /*
1388         * Set the default Active/NonOptimized Delay in milliseconds
1389         */
1390        tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1391        tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1392        tg_pt_gp->tg_pt_gp_implict_trans_secs = ALUA_DEFAULT_IMPLICT_TRANS_SECS;
1393
1394        if (def_group) {
1395                spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1396                tg_pt_gp->tg_pt_gp_id =
1397                                su_dev->t10_alua.alua_tg_pt_gps_counter++;
1398                tg_pt_gp->tg_pt_gp_valid_id = 1;
1399                su_dev->t10_alua.alua_tg_pt_gps_count++;
1400                list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1401                              &su_dev->t10_alua.tg_pt_gps_list);
1402                spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1403        }
1404
1405        return tg_pt_gp;
1406}
1407
1408int core_alua_set_tg_pt_gp_id(
1409        struct t10_alua_tg_pt_gp *tg_pt_gp,
1410        u16 tg_pt_gp_id)
1411{
1412        struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1413        struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1414        u16 tg_pt_gp_id_tmp;
1415        /*
1416         * The tg_pt_gp->tg_pt_gp_id may only be set once..
1417         */
1418        if (tg_pt_gp->tg_pt_gp_valid_id) {
1419                pr_warn("ALUA TG PT Group already has a valid ID,"
1420                        " ignoring request\n");
1421                return -EINVAL;
1422        }
1423
1424        spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1425        if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1426                pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1427                        " 0x0000ffff reached\n");
1428                spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1429                kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1430                return -ENOSPC;
1431        }
1432again:
1433        tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1434                        su_dev->t10_alua.alua_tg_pt_gps_counter++;
1435
1436        list_for_each_entry(tg_pt_gp_tmp, &su_dev->t10_alua.tg_pt_gps_list,
1437                        tg_pt_gp_list) {
1438                if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1439                        if (!tg_pt_gp_id)
1440                                goto again;
1441
1442                        pr_err("ALUA Target Port Group ID: %hu already"
1443                                " exists, ignoring request\n", tg_pt_gp_id);
1444                        spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1445                        return -EINVAL;
1446                }
1447        }
1448
1449        tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1450        tg_pt_gp->tg_pt_gp_valid_id = 1;
1451        list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1452                        &su_dev->t10_alua.tg_pt_gps_list);
1453        su_dev->t10_alua.alua_tg_pt_gps_count++;
1454        spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1455
1456        return 0;
1457}
1458
1459struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1460        struct se_port *port)
1461{
1462        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1463
1464        tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1465                                GFP_KERNEL);
1466        if (!tg_pt_gp_mem) {
1467                pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1468                return ERR_PTR(-ENOMEM);
1469        }
1470        INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1471        spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1472        atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1473
1474        tg_pt_gp_mem->tg_pt = port;
1475        port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1476
1477        return tg_pt_gp_mem;
1478}
1479
1480void core_alua_free_tg_pt_gp(
1481        struct t10_alua_tg_pt_gp *tg_pt_gp)
1482{
1483        struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1484        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1485        /*
1486         * Once we have reached this point, config_item_put() has already
1487         * been called from target_core_alua_drop_tg_pt_gp().
1488         *
1489         * Here we remove *tg_pt_gp from the global list so that
1490         * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1491         * can be made while we are releasing struct t10_alua_tg_pt_gp.
1492         */
1493        spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1494        list_del(&tg_pt_gp->tg_pt_gp_list);
1495        su_dev->t10_alua.alua_tg_pt_gps_counter--;
1496        spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1497        /*
1498         * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1499         * core_alua_get_tg_pt_gp_by_name() in
1500         * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1501         * to be released with core_alua_put_tg_pt_gp_from_name().
1502         */
1503        while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1504                cpu_relax();
1505        /*
1506         * Release reference to struct t10_alua_tg_pt_gp from all associated
1507         * struct se_port.
1508         */
1509        spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1510        list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1511                        &tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1512                if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1513                        list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1514                        tg_pt_gp->tg_pt_gp_members--;
1515                        tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1516                }
1517                spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1518                /*
1519                 * tg_pt_gp_mem is associated with a single
1520                 * se_port->sep_alua_tg_pt_gp_mem, and is released via
1521                 * core_alua_free_tg_pt_gp_mem().
1522                 *
1523                 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1524                 * assume we want to re-assocate a given tg_pt_gp_mem with
1525                 * default_tg_pt_gp.
1526                 */
1527                spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1528                if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
1529                        __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1530                                        su_dev->t10_alua.default_tg_pt_gp);
1531                } else
1532                        tg_pt_gp_mem->tg_pt_gp = NULL;
1533                spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1534
1535                spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1536        }
1537        spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1538
1539        kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1540}
1541
1542void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1543{
1544        struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1545        struct t10_alua *alua = &su_dev->t10_alua;
1546        struct t10_alua_tg_pt_gp *tg_pt_gp;
1547        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1548
1549        if (alua->alua_type != SPC3_ALUA_EMULATED)
1550                return;
1551
1552        tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1553        if (!tg_pt_gp_mem)
1554                return;
1555
1556        while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1557                cpu_relax();
1558
1559        spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1560        tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1561        if (tg_pt_gp) {
1562                spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1563                if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1564                        list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1565                        tg_pt_gp->tg_pt_gp_members--;
1566                        tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1567                }
1568                spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1569                tg_pt_gp_mem->tg_pt_gp = NULL;
1570        }
1571        spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1572
1573        kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1574}
1575
1576static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1577        struct se_subsystem_dev *su_dev,
1578        const char *name)
1579{
1580        struct t10_alua_tg_pt_gp *tg_pt_gp;
1581        struct config_item *ci;
1582
1583        spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1584        list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
1585                        tg_pt_gp_list) {
1586                if (!tg_pt_gp->tg_pt_gp_valid_id)
1587                        continue;
1588                ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1589                if (!strcmp(config_item_name(ci), name)) {
1590                        atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1591                        spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1592                        return tg_pt_gp;
1593                }
1594        }
1595        spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1596
1597        return NULL;
1598}
1599
1600static void core_alua_put_tg_pt_gp_from_name(
1601        struct t10_alua_tg_pt_gp *tg_pt_gp)
1602{
1603        struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1604
1605        spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1606        atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1607        spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1608}
1609
1610/*
1611 * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1612 */
1613void __core_alua_attach_tg_pt_gp_mem(
1614        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1615        struct t10_alua_tg_pt_gp *tg_pt_gp)
1616{
1617        spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1618        tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1619        tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1620        list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1621                        &tg_pt_gp->tg_pt_gp_mem_list);
1622        tg_pt_gp->tg_pt_gp_members++;
1623        spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1624}
1625
1626/*
1627 * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1628 */
1629static void __core_alua_drop_tg_pt_gp_mem(
1630        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1631        struct t10_alua_tg_pt_gp *tg_pt_gp)
1632{
1633        spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1634        list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1635        tg_pt_gp_mem->tg_pt_gp = NULL;
1636        tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1637        tg_pt_gp->tg_pt_gp_members--;
1638        spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1639}
1640
1641ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1642{
1643        struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1644        struct config_item *tg_pt_ci;
1645        struct t10_alua *alua = &su_dev->t10_alua;
1646        struct t10_alua_tg_pt_gp *tg_pt_gp;
1647        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1648        ssize_t len = 0;
1649
1650        if (alua->alua_type != SPC3_ALUA_EMULATED)
1651                return len;
1652
1653        tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1654        if (!tg_pt_gp_mem)
1655                return len;
1656
1657        spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1658        tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1659        if (tg_pt_gp) {
1660                tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1661                len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1662                        " %hu\nTG Port Primary Access State: %s\nTG Port "
1663                        "Primary Access Status: %s\nTG Port Secondary Access"
1664                        " State: %s\nTG Port Secondary Access Status: %s\n",
1665                        config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1666                        core_alua_dump_state(atomic_read(
1667                                        &tg_pt_gp->tg_pt_gp_alua_access_state)),
1668                        core_alua_dump_status(
1669                                tg_pt_gp->tg_pt_gp_alua_access_status),
1670                        (atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1671                        "Offline" : "None",
1672                        core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1673        }
1674        spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1675
1676        return len;
1677}
1678
1679ssize_t core_alua_store_tg_pt_gp_info(
1680        struct se_port *port,
1681        const char *page,
1682        size_t count)
1683{
1684        struct se_portal_group *tpg;
1685        struct se_lun *lun;
1686        struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1687        struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1688        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1689        unsigned char buf[TG_PT_GROUP_NAME_BUF];
1690        int move = 0;
1691
1692        tpg = port->sep_tpg;
1693        lun = port->sep_lun;
1694
1695        if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
1696                pr_warn("SPC3_ALUA_EMULATED not enabled for"
1697                        " %s/tpgt_%hu/%s\n", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1698                        tpg->se_tpg_tfo->tpg_get_tag(tpg),
1699                        config_item_name(&lun->lun_group.cg_item));
1700                return -EINVAL;
1701        }
1702
1703        if (count > TG_PT_GROUP_NAME_BUF) {
1704                pr_err("ALUA Target Port Group alias too large!\n");
1705                return -EINVAL;
1706        }
1707        memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1708        memcpy(buf, page, count);
1709        /*
1710         * Any ALUA target port group alias besides "NULL" means we will be
1711         * making a new group association.
1712         */
1713        if (strcmp(strstrip(buf), "NULL")) {
1714                /*
1715                 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1716                 * struct t10_alua_tg_pt_gp.  This reference is released with
1717                 * core_alua_put_tg_pt_gp_from_name() below.
1718                 */
1719                tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(su_dev,
1720                                        strstrip(buf));
1721                if (!tg_pt_gp_new)
1722                        return -ENODEV;
1723        }
1724        tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1725        if (!tg_pt_gp_mem) {
1726                if (tg_pt_gp_new)
1727                        core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1728                pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
1729                return -EINVAL;
1730        }
1731
1732        spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1733        tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1734        if (tg_pt_gp) {
1735                /*
1736                 * Clearing an existing tg_pt_gp association, and replacing
1737                 * with the default_tg_pt_gp.
1738                 */
1739                if (!tg_pt_gp_new) {
1740                        pr_debug("Target_Core_ConfigFS: Moving"
1741                                " %s/tpgt_%hu/%s from ALUA Target Port Group:"
1742                                " alua/%s, ID: %hu back to"
1743                                " default_tg_pt_gp\n",
1744                                tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1745                                tpg->se_tpg_tfo->tpg_get_tag(tpg),
1746                                config_item_name(&lun->lun_group.cg_item),
1747                                config_item_name(
1748                                        &tg_pt_gp->tg_pt_gp_group.cg_item),
1749                                tg_pt_gp->tg_pt_gp_id);
1750
1751                        __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1752                        __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1753                                        su_dev->t10_alua.default_tg_pt_gp);
1754                        spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1755
1756                        return count;
1757                }
1758                /*
1759                 * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1760                 */
1761                __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1762                move = 1;
1763        }
1764        /*
1765         * Associate tg_pt_gp_mem with tg_pt_gp_new.
1766         */
1767        __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1768        spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1769        pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1770                " Target Port Group: alua/%s, ID: %hu\n", (move) ?
1771                "Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1772                tpg->se_tpg_tfo->tpg_get_tag(tpg),
1773                config_item_name(&lun->lun_group.cg_item),
1774                config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1775                tg_pt_gp_new->tg_pt_gp_id);
1776
1777        core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1778        return count;
1779}
1780
1781ssize_t core_alua_show_access_type(
1782        struct t10_alua_tg_pt_gp *tg_pt_gp,
1783        char *page)
1784{
1785        if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1786            (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1787                return sprintf(page, "Implict and Explict\n");
1788        else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1789                return sprintf(page, "Implict\n");
1790        else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1791                return sprintf(page, "Explict\n");
1792        else
1793                return sprintf(page, "None\n");
1794}
1795
1796ssize_t core_alua_store_access_type(
1797        struct t10_alua_tg_pt_gp *tg_pt_gp,
1798        const char *page,
1799        size_t count)
1800{
1801        unsigned long tmp;
1802        int ret;
1803
1804        ret = strict_strtoul(page, 0, &tmp);
1805        if (ret < 0) {
1806                pr_err("Unable to extract alua_access_type\n");
1807                return -EINVAL;
1808        }
1809        if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1810                pr_err("Illegal value for alua_access_type:"
1811                                " %lu\n", tmp);
1812                return -EINVAL;
1813        }
1814        if (tmp == 3)
1815                tg_pt_gp->tg_pt_gp_alua_access_type =
1816                        TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1817        else if (tmp == 2)
1818                tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1819        else if (tmp == 1)
1820                tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1821        else
1822                tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1823
1824        return count;
1825}
1826
1827ssize_t core_alua_show_nonop_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_nonop_delay_msecs);
1832}
1833
1834ssize_t core_alua_store_nonop_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 nonop_delay_msecs\n");
1845                return -EINVAL;
1846        }
1847        if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1848                pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1849                        " ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1850                        ALUA_MAX_NONOP_DELAY_MSECS);
1851                return -EINVAL;
1852        }
1853        tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1854
1855        return count;
1856}
1857
1858ssize_t core_alua_show_trans_delay_msecs(
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_trans_delay_msecs);
1863}
1864
1865ssize_t core_alua_store_trans_delay_msecs(
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 trans_delay_msecs\n");
1876                return -EINVAL;
1877        }
1878        if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1879                pr_err("Passed trans_delay_msecs: %lu, exceeds"
1880                        " ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1881                        ALUA_MAX_TRANS_DELAY_MSECS);
1882                return -EINVAL;
1883        }
1884        tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1885
1886        return count;
1887}
1888
1889ssize_t core_alua_show_implict_trans_secs(
1890        struct t10_alua_tg_pt_gp *tg_pt_gp,
1891        char *page)
1892{
1893        return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implict_trans_secs);
1894}
1895
1896ssize_t core_alua_store_implict_trans_secs(
1897        struct t10_alua_tg_pt_gp *tg_pt_gp,
1898        const char *page,
1899        size_t count)
1900{
1901        unsigned long tmp;
1902        int ret;
1903
1904        ret = strict_strtoul(page, 0, &tmp);
1905        if (ret < 0) {
1906                pr_err("Unable to extract implict_trans_secs\n");
1907                return -EINVAL;
1908        }
1909        if (tmp > ALUA_MAX_IMPLICT_TRANS_SECS) {
1910                pr_err("Passed implict_trans_secs: %lu, exceeds"
1911                        " ALUA_MAX_IMPLICT_TRANS_SECS: %d\n", tmp,
1912                        ALUA_MAX_IMPLICT_TRANS_SECS);
1913                return  -EINVAL;
1914        }
1915        tg_pt_gp->tg_pt_gp_implict_trans_secs = (int)tmp;
1916
1917        return count;
1918}
1919
1920ssize_t core_alua_show_preferred_bit(
1921        struct t10_alua_tg_pt_gp *tg_pt_gp,
1922        char *page)
1923{
1924        return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1925}
1926
1927ssize_t core_alua_store_preferred_bit(
1928        struct t10_alua_tg_pt_gp *tg_pt_gp,
1929        const char *page,
1930        size_t count)
1931{
1932        unsigned long tmp;
1933        int ret;
1934
1935        ret = strict_strtoul(page, 0, &tmp);
1936        if (ret < 0) {
1937                pr_err("Unable to extract preferred ALUA value\n");
1938                return -EINVAL;
1939        }
1940        if ((tmp != 0) && (tmp != 1)) {
1941                pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1942                return -EINVAL;
1943        }
1944        tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1945
1946        return count;
1947}
1948
1949ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1950{
1951        if (!lun->lun_sep)
1952                return -ENODEV;
1953
1954        return sprintf(page, "%d\n",
1955                atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1956}
1957
1958ssize_t core_alua_store_offline_bit(
1959        struct se_lun *lun,
1960        const char *page,
1961        size_t count)
1962{
1963        struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1964        unsigned long tmp;
1965        int ret;
1966
1967        if (!lun->lun_sep)
1968                return -ENODEV;
1969
1970        ret = strict_strtoul(page, 0, &tmp);
1971        if (ret < 0) {
1972                pr_err("Unable to extract alua_tg_pt_offline value\n");
1973                return -EINVAL;
1974        }
1975        if ((tmp != 0) && (tmp != 1)) {
1976                pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1977                                tmp);
1978                return -EINVAL;
1979        }
1980        tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1981        if (!tg_pt_gp_mem) {
1982                pr_err("Unable to locate *tg_pt_gp_mem\n");
1983                return -EINVAL;
1984        }
1985
1986        ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1987                        lun->lun_sep, 0, (int)tmp);
1988        if (ret < 0)
1989                return -EINVAL;
1990
1991        return count;
1992}
1993
1994ssize_t core_alua_show_secondary_status(
1995        struct se_lun *lun,
1996        char *page)
1997{
1998        return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1999}
2000
2001ssize_t core_alua_store_secondary_status(
2002        struct se_lun *lun,
2003        const char *page,
2004        size_t count)
2005{
2006        unsigned long tmp;
2007        int ret;
2008
2009        ret = strict_strtoul(page, 0, &tmp);
2010        if (ret < 0) {
2011                pr_err("Unable to extract alua_tg_pt_status\n");
2012                return -EINVAL;
2013        }
2014        if ((tmp != ALUA_STATUS_NONE) &&
2015            (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
2016            (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
2017                pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2018                                tmp);
2019                return -EINVAL;
2020        }
2021        lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
2022
2023        return count;
2024}
2025
2026ssize_t core_alua_show_secondary_write_metadata(
2027        struct se_lun *lun,
2028        char *page)
2029{
2030        return sprintf(page, "%d\n",
2031                        lun->lun_sep->sep_tg_pt_secondary_write_md);
2032}
2033
2034ssize_t core_alua_store_secondary_write_metadata(
2035        struct se_lun *lun,
2036        const char *page,
2037        size_t count)
2038{
2039        unsigned long tmp;
2040        int ret;
2041
2042        ret = strict_strtoul(page, 0, &tmp);
2043        if (ret < 0) {
2044                pr_err("Unable to extract alua_tg_pt_write_md\n");
2045                return -EINVAL;
2046        }
2047        if ((tmp != 0) && (tmp != 1)) {
2048                pr_err("Illegal value for alua_tg_pt_write_md:"
2049                                " %lu\n", tmp);
2050                return -EINVAL;
2051        }
2052        lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
2053
2054        return count;
2055}
2056
2057int core_setup_alua(struct se_device *dev, int force_pt)
2058{
2059        struct se_subsystem_dev *su_dev = dev->se_sub_dev;
2060        struct t10_alua *alua = &su_dev->t10_alua;
2061        struct t10_alua_lu_gp_member *lu_gp_mem;
2062        /*
2063         * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
2064         * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
2065         * cause a problem because libata and some SATA RAID HBAs appear
2066         * under Linux/SCSI, but emulate SCSI logic themselves.
2067         */
2068        if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
2069            !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
2070                alua->alua_type = SPC_ALUA_PASSTHROUGH;
2071                alua->alua_state_check = &core_alua_state_check_nop;
2072                pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
2073                        " emulation\n", dev->transport->name);
2074                return 0;
2075        }
2076        /*
2077         * If SPC-3 or above is reported by real or emulated struct se_device,
2078         * use emulated ALUA.
2079         */
2080        if (dev->transport->get_device_rev(dev) >= SCSI_3) {
2081                pr_debug("%s: Enabling ALUA Emulation for SPC-3"
2082                        " device\n", dev->transport->name);
2083                /*
2084                 * Associate this struct se_device with the default ALUA
2085                 * LUN Group.
2086                 */
2087                lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2088                if (IS_ERR(lu_gp_mem))
2089                        return PTR_ERR(lu_gp_mem);
2090
2091                alua->alua_type = SPC3_ALUA_EMULATED;
2092                alua->alua_state_check = &core_alua_state_check;
2093                spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2094                __core_alua_attach_lu_gp_mem(lu_gp_mem,
2095                                default_lu_gp);
2096                spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2097
2098                pr_debug("%s: Adding to default ALUA LU Group:"
2099                        " core/alua/lu_gps/default_lu_gp\n",
2100                        dev->transport->name);
2101        } else {
2102                alua->alua_type = SPC2_ALUA_DISABLED;
2103                alua->alua_state_check = &core_alua_state_check_nop;
2104                pr_debug("%s: Disabling ALUA Emulation for SPC-2"
2105                        " device\n", dev->transport->name);
2106        }
2107
2108        return 0;
2109}
2110
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