linux/drivers/target/target_core_alua.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*******************************************************************************
   3 * Filename:  target_core_alua.c
   4 *
   5 * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
   6 *
   7 * (c) Copyright 2009-2013 Datera, Inc.
   8 *
   9 * Nicholas A. Bellinger <nab@kernel.org>
  10 *
  11 ******************************************************************************/
  12
  13#include <linux/slab.h>
  14#include <linux/spinlock.h>
  15#include <linux/configfs.h>
  16#include <linux/delay.h>
  17#include <linux/export.h>
  18#include <linux/fcntl.h>
  19#include <linux/file.h>
  20#include <linux/fs.h>
  21#include <scsi/scsi_proto.h>
  22#include <asm/unaligned.h>
  23
  24#include <target/target_core_base.h>
  25#include <target/target_core_backend.h>
  26#include <target/target_core_fabric.h>
  27
  28#include "target_core_internal.h"
  29#include "target_core_alua.h"
  30#include "target_core_ua.h"
  31
  32static sense_reason_t core_alua_check_transition(int state, int valid,
  33                                                 int *primary, int explicit);
  34static int core_alua_set_tg_pt_secondary_state(
  35                struct se_lun *lun, int explicit, int offline);
  36
  37static char *core_alua_dump_state(int state);
  38
  39static void __target_attach_tg_pt_gp(struct se_lun *lun,
  40                struct t10_alua_tg_pt_gp *tg_pt_gp);
  41
  42static u16 alua_lu_gps_counter;
  43static u32 alua_lu_gps_count;
  44
  45static DEFINE_SPINLOCK(lu_gps_lock);
  46static LIST_HEAD(lu_gps_list);
  47
  48struct t10_alua_lu_gp *default_lu_gp;
  49
  50/*
  51 * REPORT REFERRALS
  52 *
  53 * See sbc3r35 section 5.23
  54 */
  55sense_reason_t
  56target_emulate_report_referrals(struct se_cmd *cmd)
  57{
  58        struct se_device *dev = cmd->se_dev;
  59        struct t10_alua_lba_map *map;
  60        struct t10_alua_lba_map_member *map_mem;
  61        unsigned char *buf;
  62        u32 rd_len = 0, off;
  63
  64        if (cmd->data_length < 4) {
  65                pr_warn("REPORT REFERRALS allocation length %u too"
  66                        " small\n", cmd->data_length);
  67                return TCM_INVALID_CDB_FIELD;
  68        }
  69
  70        buf = transport_kmap_data_sg(cmd);
  71        if (!buf)
  72                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
  73
  74        off = 4;
  75        spin_lock(&dev->t10_alua.lba_map_lock);
  76        if (list_empty(&dev->t10_alua.lba_map_list)) {
  77                spin_unlock(&dev->t10_alua.lba_map_lock);
  78                transport_kunmap_data_sg(cmd);
  79
  80                return TCM_UNSUPPORTED_SCSI_OPCODE;
  81        }
  82
  83        list_for_each_entry(map, &dev->t10_alua.lba_map_list,
  84                            lba_map_list) {
  85                int desc_num = off + 3;
  86                int pg_num;
  87
  88                off += 4;
  89                if (cmd->data_length > off)
  90                        put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
  91                off += 8;
  92                if (cmd->data_length > off)
  93                        put_unaligned_be64(map->lba_map_last_lba, &buf[off]);
  94                off += 8;
  95                rd_len += 20;
  96                pg_num = 0;
  97                list_for_each_entry(map_mem, &map->lba_map_mem_list,
  98                                    lba_map_mem_list) {
  99                        int alua_state = map_mem->lba_map_mem_alua_state;
 100                        int alua_pg_id = map_mem->lba_map_mem_alua_pg_id;
 101
 102                        if (cmd->data_length > off)
 103                                buf[off] = alua_state & 0x0f;
 104                        off += 2;
 105                        if (cmd->data_length > off)
 106                                buf[off] = (alua_pg_id >> 8) & 0xff;
 107                        off++;
 108                        if (cmd->data_length > off)
 109                                buf[off] = (alua_pg_id & 0xff);
 110                        off++;
 111                        rd_len += 4;
 112                        pg_num++;
 113                }
 114                if (cmd->data_length > desc_num)
 115                        buf[desc_num] = pg_num;
 116        }
 117        spin_unlock(&dev->t10_alua.lba_map_lock);
 118
 119        /*
 120         * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 121         */
 122        put_unaligned_be16(rd_len, &buf[2]);
 123
 124        transport_kunmap_data_sg(cmd);
 125
 126        target_complete_cmd(cmd, GOOD);
 127        return 0;
 128}
 129
 130/*
 131 * REPORT_TARGET_PORT_GROUPS
 132 *
 133 * See spc4r17 section 6.27
 134 */
 135sense_reason_t
 136target_emulate_report_target_port_groups(struct se_cmd *cmd)
 137{
 138        struct se_device *dev = cmd->se_dev;
 139        struct t10_alua_tg_pt_gp *tg_pt_gp;
 140        struct se_lun *lun;
 141        unsigned char *buf;
 142        u32 rd_len = 0, off;
 143        int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
 144
 145        /*
 146         * Skip over RESERVED area to first Target port group descriptor
 147         * depending on the PARAMETER DATA FORMAT type..
 148         */
 149        if (ext_hdr != 0)
 150                off = 8;
 151        else
 152                off = 4;
 153
 154        if (cmd->data_length < off) {
 155                pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
 156                        " small for %s header\n", cmd->data_length,
 157                        (ext_hdr) ? "extended" : "normal");
 158                return TCM_INVALID_CDB_FIELD;
 159        }
 160        buf = transport_kmap_data_sg(cmd);
 161        if (!buf)
 162                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 163
 164        spin_lock(&dev->t10_alua.tg_pt_gps_lock);
 165        list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
 166                        tg_pt_gp_list) {
 167                /*
 168                 * Check if the Target port group and Target port descriptor list
 169                 * based on tg_pt_gp_members count will fit into the response payload.
 170                 * Otherwise, bump rd_len to let the initiator know we have exceeded
 171                 * the allocation length and the response is truncated.
 172                 */
 173                if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
 174                     cmd->data_length) {
 175                        rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
 176                        continue;
 177                }
 178                /*
 179                 * PREF: Preferred target port bit, determine if this
 180                 * bit should be set for port group.
 181                 */
 182                if (tg_pt_gp->tg_pt_gp_pref)
 183                        buf[off] = 0x80;
 184                /*
 185                 * Set the ASYMMETRIC ACCESS State
 186                 */
 187                buf[off++] |= tg_pt_gp->tg_pt_gp_alua_access_state & 0xff;
 188                /*
 189                 * Set supported ASYMMETRIC ACCESS State bits
 190                 */
 191                buf[off++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
 192                /*
 193                 * TARGET PORT GROUP
 194                 */
 195                put_unaligned_be16(tg_pt_gp->tg_pt_gp_id, &buf[off]);
 196                off += 2;
 197
 198                off++; /* Skip over Reserved */
 199                /*
 200                 * STATUS CODE
 201                 */
 202                buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
 203                /*
 204                 * Vendor Specific field
 205                 */
 206                buf[off++] = 0x00;
 207                /*
 208                 * TARGET PORT COUNT
 209                 */
 210                buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
 211                rd_len += 8;
 212
 213                spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 214                list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
 215                                lun_tg_pt_gp_link) {
 216                        /*
 217                         * Start Target Port descriptor format
 218                         *
 219                         * See spc4r17 section 6.2.7 Table 247
 220                         */
 221                        off += 2; /* Skip over Obsolete */
 222                        /*
 223                         * Set RELATIVE TARGET PORT IDENTIFIER
 224                         */
 225                        put_unaligned_be16(lun->lun_rtpi, &buf[off]);
 226                        off += 2;
 227                        rd_len += 4;
 228                }
 229                spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 230        }
 231        spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 232        /*
 233         * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 234         */
 235        put_unaligned_be32(rd_len, &buf[0]);
 236
 237        /*
 238         * Fill in the Extended header parameter data format if requested
 239         */
 240        if (ext_hdr != 0) {
 241                buf[4] = 0x10;
 242                /*
 243                 * Set the implicit transition time (in seconds) for the application
 244                 * client to use as a base for it's transition timeout value.
 245                 *
 246                 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
 247                 * this CDB was received upon to determine this value individually
 248                 * for ALUA target port group.
 249                 */
 250                spin_lock(&cmd->se_lun->lun_tg_pt_gp_lock);
 251                tg_pt_gp = cmd->se_lun->lun_tg_pt_gp;
 252                if (tg_pt_gp)
 253                        buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
 254                spin_unlock(&cmd->se_lun->lun_tg_pt_gp_lock);
 255        }
 256        transport_kunmap_data_sg(cmd);
 257
 258        target_complete_cmd_with_length(cmd, GOOD, rd_len + 4);
 259        return 0;
 260}
 261
 262/*
 263 * SET_TARGET_PORT_GROUPS for explicit ALUA operation.
 264 *
 265 * See spc4r17 section 6.35
 266 */
 267sense_reason_t
 268target_emulate_set_target_port_groups(struct se_cmd *cmd)
 269{
 270        struct se_device *dev = cmd->se_dev;
 271        struct se_lun *l_lun = cmd->se_lun;
 272        struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
 273        struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
 274        unsigned char *buf;
 275        unsigned char *ptr;
 276        sense_reason_t rc = TCM_NO_SENSE;
 277        u32 len = 4; /* Skip over RESERVED area in header */
 278        int alua_access_state, primary = 0, valid_states;
 279        u16 tg_pt_id, rtpi;
 280
 281        if (cmd->data_length < 4) {
 282                pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
 283                        " small\n", cmd->data_length);
 284                return TCM_INVALID_PARAMETER_LIST;
 285        }
 286
 287        buf = transport_kmap_data_sg(cmd);
 288        if (!buf)
 289                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 290
 291        /*
 292         * Determine if explicit ALUA via SET_TARGET_PORT_GROUPS is allowed
 293         * for the local tg_pt_gp.
 294         */
 295        spin_lock(&l_lun->lun_tg_pt_gp_lock);
 296        l_tg_pt_gp = l_lun->lun_tg_pt_gp;
 297        if (!l_tg_pt_gp) {
 298                spin_unlock(&l_lun->lun_tg_pt_gp_lock);
 299                pr_err("Unable to access l_lun->tg_pt_gp\n");
 300                rc = TCM_UNSUPPORTED_SCSI_OPCODE;
 301                goto out;
 302        }
 303
 304        if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
 305                spin_unlock(&l_lun->lun_tg_pt_gp_lock);
 306                pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
 307                                " while TPGS_EXPLICIT_ALUA is disabled\n");
 308                rc = TCM_UNSUPPORTED_SCSI_OPCODE;
 309                goto out;
 310        }
 311        valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
 312        spin_unlock(&l_lun->lun_tg_pt_gp_lock);
 313
 314        ptr = &buf[4]; /* Skip over RESERVED area in header */
 315
 316        while (len < cmd->data_length) {
 317                bool found = false;
 318                alua_access_state = (ptr[0] & 0x0f);
 319                /*
 320                 * Check the received ALUA access state, and determine if
 321                 * the state is a primary or secondary target port asymmetric
 322                 * access state.
 323                 */
 324                rc = core_alua_check_transition(alua_access_state, valid_states,
 325                                                &primary, 1);
 326                if (rc) {
 327                        /*
 328                         * If the SET TARGET PORT GROUPS attempts to establish
 329                         * an invalid combination of target port asymmetric
 330                         * access states or attempts to establish an
 331                         * unsupported target port asymmetric access state,
 332                         * then the command shall be terminated with CHECK
 333                         * CONDITION status, with the sense key set to ILLEGAL
 334                         * REQUEST, and the additional sense code set to INVALID
 335                         * FIELD IN PARAMETER LIST.
 336                         */
 337                        goto out;
 338                }
 339
 340                /*
 341                 * If the ASYMMETRIC ACCESS STATE field (see table 267)
 342                 * specifies a primary target port asymmetric access state,
 343                 * then the TARGET PORT GROUP OR TARGET PORT field specifies
 344                 * a primary target port group for which the primary target
 345                 * port asymmetric access state shall be changed. If the
 346                 * ASYMMETRIC ACCESS STATE field specifies a secondary target
 347                 * port asymmetric access state, then the TARGET PORT GROUP OR
 348                 * TARGET PORT field specifies the relative target port
 349                 * identifier (see 3.1.120) of the target port for which the
 350                 * secondary target port asymmetric access state shall be
 351                 * changed.
 352                 */
 353                if (primary) {
 354                        tg_pt_id = get_unaligned_be16(ptr + 2);
 355                        /*
 356                         * Locate the matching target port group ID from
 357                         * the global tg_pt_gp list
 358                         */
 359                        spin_lock(&dev->t10_alua.tg_pt_gps_lock);
 360                        list_for_each_entry(tg_pt_gp,
 361                                        &dev->t10_alua.tg_pt_gps_list,
 362                                        tg_pt_gp_list) {
 363                                if (!tg_pt_gp->tg_pt_gp_valid_id)
 364                                        continue;
 365
 366                                if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
 367                                        continue;
 368
 369                                atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
 370
 371                                spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 372
 373                                if (!core_alua_do_port_transition(tg_pt_gp,
 374                                                dev, l_lun, nacl,
 375                                                alua_access_state, 1))
 376                                        found = true;
 377
 378                                spin_lock(&dev->t10_alua.tg_pt_gps_lock);
 379                                atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
 380                                break;
 381                        }
 382                        spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 383                } else {
 384                        struct se_lun *lun;
 385
 386                        /*
 387                         * Extract the RELATIVE TARGET PORT IDENTIFIER to identify
 388                         * the Target Port in question for the the incoming
 389                         * SET_TARGET_PORT_GROUPS op.
 390                         */
 391                        rtpi = get_unaligned_be16(ptr + 2);
 392                        /*
 393                         * Locate the matching relative target port identifier
 394                         * for the struct se_device storage object.
 395                         */
 396                        spin_lock(&dev->se_port_lock);
 397                        list_for_each_entry(lun, &dev->dev_sep_list,
 398                                                        lun_dev_link) {
 399                                if (lun->lun_rtpi != rtpi)
 400                                        continue;
 401
 402                                // XXX: racy unlock
 403                                spin_unlock(&dev->se_port_lock);
 404
 405                                if (!core_alua_set_tg_pt_secondary_state(
 406                                                lun, 1, 1))
 407                                        found = true;
 408
 409                                spin_lock(&dev->se_port_lock);
 410                                break;
 411                        }
 412                        spin_unlock(&dev->se_port_lock);
 413                }
 414
 415                if (!found) {
 416                        rc = TCM_INVALID_PARAMETER_LIST;
 417                        goto out;
 418                }
 419
 420                ptr += 4;
 421                len += 4;
 422        }
 423
 424out:
 425        transport_kunmap_data_sg(cmd);
 426        if (!rc)
 427                target_complete_cmd(cmd, GOOD);
 428        return rc;
 429}
 430
 431static inline void set_ascq(struct se_cmd *cmd, u8 alua_ascq)
 432{
 433        /*
 434         * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
 435         * The ALUA additional sense code qualifier (ASCQ) is determined
 436         * by the ALUA primary or secondary access state..
 437         */
 438        pr_debug("[%s]: ALUA TG Port not available, "
 439                "SenseKey: NOT_READY, ASC/ASCQ: "
 440                "0x04/0x%02x\n",
 441                cmd->se_tfo->fabric_name, alua_ascq);
 442
 443        cmd->scsi_asc = 0x04;
 444        cmd->scsi_ascq = alua_ascq;
 445}
 446
 447static inline void core_alua_state_nonoptimized(
 448        struct se_cmd *cmd,
 449        unsigned char *cdb,
 450        int nonop_delay_msecs)
 451{
 452        /*
 453         * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
 454         * later to determine if processing of this cmd needs to be
 455         * temporarily delayed for the Active/NonOptimized primary access state.
 456         */
 457        cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
 458        cmd->alua_nonop_delay = nonop_delay_msecs;
 459}
 460
 461static inline int core_alua_state_lba_dependent(
 462        struct se_cmd *cmd,
 463        struct t10_alua_tg_pt_gp *tg_pt_gp)
 464{
 465        struct se_device *dev = cmd->se_dev;
 466        u64 segment_size, segment_mult, sectors, lba;
 467
 468        /* Only need to check for cdb actually containing LBAs */
 469        if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB))
 470                return 0;
 471
 472        spin_lock(&dev->t10_alua.lba_map_lock);
 473        segment_size = dev->t10_alua.lba_map_segment_size;
 474        segment_mult = dev->t10_alua.lba_map_segment_multiplier;
 475        sectors = cmd->data_length / dev->dev_attrib.block_size;
 476
 477        lba = cmd->t_task_lba;
 478        while (lba < cmd->t_task_lba + sectors) {
 479                struct t10_alua_lba_map *cur_map = NULL, *map;
 480                struct t10_alua_lba_map_member *map_mem;
 481
 482                list_for_each_entry(map, &dev->t10_alua.lba_map_list,
 483                                    lba_map_list) {
 484                        u64 start_lba, last_lba;
 485                        u64 first_lba = map->lba_map_first_lba;
 486
 487                        if (segment_mult) {
 488                                u64 tmp = lba;
 489                                start_lba = do_div(tmp, segment_size * segment_mult);
 490
 491                                last_lba = first_lba + segment_size - 1;
 492                                if (start_lba >= first_lba &&
 493                                    start_lba <= last_lba) {
 494                                        lba += segment_size;
 495                                        cur_map = map;
 496                                        break;
 497                                }
 498                        } else {
 499                                last_lba = map->lba_map_last_lba;
 500                                if (lba >= first_lba && lba <= last_lba) {
 501                                        lba = last_lba + 1;
 502                                        cur_map = map;
 503                                        break;
 504                                }
 505                        }
 506                }
 507                if (!cur_map) {
 508                        spin_unlock(&dev->t10_alua.lba_map_lock);
 509                        set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
 510                        return 1;
 511                }
 512                list_for_each_entry(map_mem, &cur_map->lba_map_mem_list,
 513                                    lba_map_mem_list) {
 514                        if (map_mem->lba_map_mem_alua_pg_id !=
 515                            tg_pt_gp->tg_pt_gp_id)
 516                                continue;
 517                        switch(map_mem->lba_map_mem_alua_state) {
 518                        case ALUA_ACCESS_STATE_STANDBY:
 519                                spin_unlock(&dev->t10_alua.lba_map_lock);
 520                                set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
 521                                return 1;
 522                        case ALUA_ACCESS_STATE_UNAVAILABLE:
 523                                spin_unlock(&dev->t10_alua.lba_map_lock);
 524                                set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
 525                                return 1;
 526                        default:
 527                                break;
 528                        }
 529                }
 530        }
 531        spin_unlock(&dev->t10_alua.lba_map_lock);
 532        return 0;
 533}
 534
 535static inline int core_alua_state_standby(
 536        struct se_cmd *cmd,
 537        unsigned char *cdb)
 538{
 539        /*
 540         * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
 541         * spc4r17 section 5.9.2.4.4
 542         */
 543        switch (cdb[0]) {
 544        case INQUIRY:
 545        case LOG_SELECT:
 546        case LOG_SENSE:
 547        case MODE_SELECT:
 548        case MODE_SENSE:
 549        case REPORT_LUNS:
 550        case RECEIVE_DIAGNOSTIC:
 551        case SEND_DIAGNOSTIC:
 552        case READ_CAPACITY:
 553                return 0;
 554        case SERVICE_ACTION_IN_16:
 555                switch (cdb[1] & 0x1f) {
 556                case SAI_READ_CAPACITY_16:
 557                        return 0;
 558                default:
 559                        set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
 560                        return 1;
 561                }
 562        case MAINTENANCE_IN:
 563                switch (cdb[1] & 0x1f) {
 564                case MI_REPORT_TARGET_PGS:
 565                        return 0;
 566                default:
 567                        set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
 568                        return 1;
 569                }
 570        case MAINTENANCE_OUT:
 571                switch (cdb[1]) {
 572                case MO_SET_TARGET_PGS:
 573                        return 0;
 574                default:
 575                        set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
 576                        return 1;
 577                }
 578        case REQUEST_SENSE:
 579        case PERSISTENT_RESERVE_IN:
 580        case PERSISTENT_RESERVE_OUT:
 581        case READ_BUFFER:
 582        case WRITE_BUFFER:
 583                return 0;
 584        default:
 585                set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
 586                return 1;
 587        }
 588
 589        return 0;
 590}
 591
 592static inline int core_alua_state_unavailable(
 593        struct se_cmd *cmd,
 594        unsigned char *cdb)
 595{
 596        /*
 597         * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
 598         * spc4r17 section 5.9.2.4.5
 599         */
 600        switch (cdb[0]) {
 601        case INQUIRY:
 602        case REPORT_LUNS:
 603                return 0;
 604        case MAINTENANCE_IN:
 605                switch (cdb[1] & 0x1f) {
 606                case MI_REPORT_TARGET_PGS:
 607                        return 0;
 608                default:
 609                        set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
 610                        return 1;
 611                }
 612        case MAINTENANCE_OUT:
 613                switch (cdb[1]) {
 614                case MO_SET_TARGET_PGS:
 615                        return 0;
 616                default:
 617                        set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
 618                        return 1;
 619                }
 620        case REQUEST_SENSE:
 621        case READ_BUFFER:
 622        case WRITE_BUFFER:
 623                return 0;
 624        default:
 625                set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
 626                return 1;
 627        }
 628
 629        return 0;
 630}
 631
 632static inline int core_alua_state_transition(
 633        struct se_cmd *cmd,
 634        unsigned char *cdb)
 635{
 636        /*
 637         * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
 638         * spc4r17 section 5.9.2.5
 639         */
 640        switch (cdb[0]) {
 641        case INQUIRY:
 642        case REPORT_LUNS:
 643                return 0;
 644        case MAINTENANCE_IN:
 645                switch (cdb[1] & 0x1f) {
 646                case MI_REPORT_TARGET_PGS:
 647                        return 0;
 648                default:
 649                        set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
 650                        return 1;
 651                }
 652        case REQUEST_SENSE:
 653        case READ_BUFFER:
 654        case WRITE_BUFFER:
 655                return 0;
 656        default:
 657                set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
 658                return 1;
 659        }
 660
 661        return 0;
 662}
 663
 664/*
 665 * return 1: Is used to signal LUN not accessible, and check condition/not ready
 666 * return 0: Used to signal success
 667 * return -1: Used to signal failure, and invalid cdb field
 668 */
 669sense_reason_t
 670target_alua_state_check(struct se_cmd *cmd)
 671{
 672        struct se_device *dev = cmd->se_dev;
 673        unsigned char *cdb = cmd->t_task_cdb;
 674        struct se_lun *lun = cmd->se_lun;
 675        struct t10_alua_tg_pt_gp *tg_pt_gp;
 676        int out_alua_state, nonop_delay_msecs;
 677
 678        if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
 679                return 0;
 680        if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
 681                return 0;
 682
 683        /*
 684         * First, check for a struct se_port specific secondary ALUA target port
 685         * access state: OFFLINE
 686         */
 687        if (atomic_read(&lun->lun_tg_pt_secondary_offline)) {
 688                pr_debug("ALUA: Got secondary offline status for local"
 689                                " target port\n");
 690                set_ascq(cmd, ASCQ_04H_ALUA_OFFLINE);
 691                return TCM_CHECK_CONDITION_NOT_READY;
 692        }
 693
 694        if (!lun->lun_tg_pt_gp)
 695                return 0;
 696
 697        spin_lock(&lun->lun_tg_pt_gp_lock);
 698        tg_pt_gp = lun->lun_tg_pt_gp;
 699        out_alua_state = tg_pt_gp->tg_pt_gp_alua_access_state;
 700        nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
 701
 702        // XXX: keeps using tg_pt_gp witout reference after unlock
 703        spin_unlock(&lun->lun_tg_pt_gp_lock);
 704        /*
 705         * Process ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED in a separate conditional
 706         * statement so the compiler knows explicitly to check this case first.
 707         * For the Optimized ALUA access state case, we want to process the
 708         * incoming fabric cmd ASAP..
 709         */
 710        if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED)
 711                return 0;
 712
 713        switch (out_alua_state) {
 714        case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 715                core_alua_state_nonoptimized(cmd, cdb, nonop_delay_msecs);
 716                break;
 717        case ALUA_ACCESS_STATE_STANDBY:
 718                if (core_alua_state_standby(cmd, cdb))
 719                        return TCM_CHECK_CONDITION_NOT_READY;
 720                break;
 721        case ALUA_ACCESS_STATE_UNAVAILABLE:
 722                if (core_alua_state_unavailable(cmd, cdb))
 723                        return TCM_CHECK_CONDITION_NOT_READY;
 724                break;
 725        case ALUA_ACCESS_STATE_TRANSITION:
 726                if (core_alua_state_transition(cmd, cdb))
 727                        return TCM_CHECK_CONDITION_NOT_READY;
 728                break;
 729        case ALUA_ACCESS_STATE_LBA_DEPENDENT:
 730                if (core_alua_state_lba_dependent(cmd, tg_pt_gp))
 731                        return TCM_CHECK_CONDITION_NOT_READY;
 732                break;
 733        /*
 734         * OFFLINE is a secondary ALUA target port group access state, that is
 735         * handled above with struct se_lun->lun_tg_pt_secondary_offline=1
 736         */
 737        case ALUA_ACCESS_STATE_OFFLINE:
 738        default:
 739                pr_err("Unknown ALUA access state: 0x%02x\n",
 740                                out_alua_state);
 741                return TCM_INVALID_CDB_FIELD;
 742        }
 743
 744        return 0;
 745}
 746
 747/*
 748 * Check implicit and explicit ALUA state change request.
 749 */
 750static sense_reason_t
 751core_alua_check_transition(int state, int valid, int *primary, int explicit)
 752{
 753        /*
 754         * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
 755         * defined as primary target port asymmetric access states.
 756         */
 757        switch (state) {
 758        case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
 759                if (!(valid & ALUA_AO_SUP))
 760                        goto not_supported;
 761                *primary = 1;
 762                break;
 763        case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 764                if (!(valid & ALUA_AN_SUP))
 765                        goto not_supported;
 766                *primary = 1;
 767                break;
 768        case ALUA_ACCESS_STATE_STANDBY:
 769                if (!(valid & ALUA_S_SUP))
 770                        goto not_supported;
 771                *primary = 1;
 772                break;
 773        case ALUA_ACCESS_STATE_UNAVAILABLE:
 774                if (!(valid & ALUA_U_SUP))
 775                        goto not_supported;
 776                *primary = 1;
 777                break;
 778        case ALUA_ACCESS_STATE_LBA_DEPENDENT:
 779                if (!(valid & ALUA_LBD_SUP))
 780                        goto not_supported;
 781                *primary = 1;
 782                break;
 783        case ALUA_ACCESS_STATE_OFFLINE:
 784                /*
 785                 * OFFLINE state is defined as a secondary target port
 786                 * asymmetric access state.
 787                 */
 788                if (!(valid & ALUA_O_SUP))
 789                        goto not_supported;
 790                *primary = 0;
 791                break;
 792        case ALUA_ACCESS_STATE_TRANSITION:
 793                if (!(valid & ALUA_T_SUP) || explicit)
 794                        /*
 795                         * Transitioning is set internally and by tcmu daemon,
 796                         * and cannot be selected through a STPG.
 797                         */
 798                        goto not_supported;
 799                *primary = 0;
 800                break;
 801        default:
 802                pr_err("Unknown ALUA access state: 0x%02x\n", state);
 803                return TCM_INVALID_PARAMETER_LIST;
 804        }
 805
 806        return 0;
 807
 808not_supported:
 809        pr_err("ALUA access state %s not supported",
 810               core_alua_dump_state(state));
 811        return TCM_INVALID_PARAMETER_LIST;
 812}
 813
 814static char *core_alua_dump_state(int state)
 815{
 816        switch (state) {
 817        case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
 818                return "Active/Optimized";
 819        case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 820                return "Active/NonOptimized";
 821        case ALUA_ACCESS_STATE_LBA_DEPENDENT:
 822                return "LBA Dependent";
 823        case ALUA_ACCESS_STATE_STANDBY:
 824                return "Standby";
 825        case ALUA_ACCESS_STATE_UNAVAILABLE:
 826                return "Unavailable";
 827        case ALUA_ACCESS_STATE_OFFLINE:
 828                return "Offline";
 829        case ALUA_ACCESS_STATE_TRANSITION:
 830                return "Transitioning";
 831        default:
 832                return "Unknown";
 833        }
 834
 835        return NULL;
 836}
 837
 838char *core_alua_dump_status(int status)
 839{
 840        switch (status) {
 841        case ALUA_STATUS_NONE:
 842                return "None";
 843        case ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG:
 844                return "Altered by Explicit STPG";
 845        case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
 846                return "Altered by Implicit ALUA";
 847        default:
 848                return "Unknown";
 849        }
 850
 851        return NULL;
 852}
 853
 854/*
 855 * Used by fabric modules to determine when we need to delay processing
 856 * for the Active/NonOptimized paths..
 857 */
 858int core_alua_check_nonop_delay(
 859        struct se_cmd *cmd)
 860{
 861        if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
 862                return 0;
 863        if (in_interrupt())
 864                return 0;
 865        /*
 866         * The ALUA Active/NonOptimized access state delay can be disabled
 867         * in via configfs with a value of zero
 868         */
 869        if (!cmd->alua_nonop_delay)
 870                return 0;
 871        /*
 872         * struct se_cmd->alua_nonop_delay gets set by a target port group
 873         * defined interval in core_alua_state_nonoptimized()
 874         */
 875        msleep_interruptible(cmd->alua_nonop_delay);
 876        return 0;
 877}
 878EXPORT_SYMBOL(core_alua_check_nonop_delay);
 879
 880static int core_alua_write_tpg_metadata(
 881        const char *path,
 882        unsigned char *md_buf,
 883        u32 md_buf_len)
 884{
 885        struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
 886        loff_t pos = 0;
 887        int ret;
 888
 889        if (IS_ERR(file)) {
 890                pr_err("filp_open(%s) for ALUA metadata failed\n", path);
 891                return -ENODEV;
 892        }
 893        ret = kernel_write(file, md_buf, md_buf_len, &pos);
 894        if (ret < 0)
 895                pr_err("Error writing ALUA metadata file: %s\n", path);
 896        fput(file);
 897        return (ret < 0) ? -EIO : 0;
 898}
 899
 900static int core_alua_update_tpg_primary_metadata(
 901        struct t10_alua_tg_pt_gp *tg_pt_gp)
 902{
 903        unsigned char *md_buf;
 904        struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
 905        char *path;
 906        int len, rc;
 907
 908        lockdep_assert_held(&tg_pt_gp->tg_pt_gp_transition_mutex);
 909
 910        md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
 911        if (!md_buf) {
 912                pr_err("Unable to allocate buf for ALUA metadata\n");
 913                return -ENOMEM;
 914        }
 915
 916        len = snprintf(md_buf, ALUA_MD_BUF_LEN,
 917                        "tg_pt_gp_id=%hu\n"
 918                        "alua_access_state=0x%02x\n"
 919                        "alua_access_status=0x%02x\n",
 920                        tg_pt_gp->tg_pt_gp_id,
 921                        tg_pt_gp->tg_pt_gp_alua_access_state,
 922                        tg_pt_gp->tg_pt_gp_alua_access_status);
 923
 924        rc = -ENOMEM;
 925        path = kasprintf(GFP_KERNEL, "%s/alua/tpgs_%s/%s", db_root,
 926                        &wwn->unit_serial[0],
 927                        config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 928        if (path) {
 929                rc = core_alua_write_tpg_metadata(path, md_buf, len);
 930                kfree(path);
 931        }
 932        kfree(md_buf);
 933        return rc;
 934}
 935
 936static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
 937{
 938        struct se_dev_entry *se_deve;
 939        struct se_lun *lun;
 940        struct se_lun_acl *lacl;
 941
 942        spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 943        list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
 944                                lun_tg_pt_gp_link) {
 945                /*
 946                 * After an implicit target port asymmetric access state
 947                 * change, a device server shall establish a unit attention
 948                 * condition for the initiator port associated with every I_T
 949                 * nexus with the additional sense code set to ASYMMETRIC
 950                 * ACCESS STATE CHANGED.
 951                 *
 952                 * After an explicit target port asymmetric access state
 953                 * change, a device server shall establish a unit attention
 954                 * condition with the additional sense code set to ASYMMETRIC
 955                 * ACCESS STATE CHANGED for the initiator port associated with
 956                 * every I_T nexus other than the I_T nexus on which the SET
 957                 * TARGET PORT GROUPS command
 958                 */
 959                if (!percpu_ref_tryget_live(&lun->lun_ref))
 960                        continue;
 961                spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 962
 963                spin_lock(&lun->lun_deve_lock);
 964                list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
 965                        lacl = rcu_dereference_check(se_deve->se_lun_acl,
 966                                        lockdep_is_held(&lun->lun_deve_lock));
 967
 968                        /*
 969                         * spc4r37 p.242:
 970                         * After an explicit target port asymmetric access
 971                         * state change, a device server shall establish a
 972                         * unit attention condition with the additional sense
 973                         * code set to ASYMMETRIC ACCESS STATE CHANGED for
 974                         * the initiator port associated with every I_T nexus
 975                         * other than the I_T nexus on which the SET TARGET
 976                         * PORT GROUPS command was received.
 977                         */
 978                        if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
 979                             ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
 980                           (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
 981                            (tg_pt_gp->tg_pt_gp_alua_lun == lun))
 982                                continue;
 983
 984                        /*
 985                         * se_deve->se_lun_acl pointer may be NULL for a
 986                         * entry created without explicit Node+MappedLUN ACLs
 987                         */
 988                        if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
 989                            (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
 990                                continue;
 991
 992                        core_scsi3_ua_allocate(se_deve, 0x2A,
 993                                ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
 994                }
 995                spin_unlock(&lun->lun_deve_lock);
 996
 997                spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 998                percpu_ref_put(&lun->lun_ref);
 999        }
1000        spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1001}
1002
1003static int core_alua_do_transition_tg_pt(
1004        struct t10_alua_tg_pt_gp *tg_pt_gp,
1005        int new_state,
1006        int explicit)
1007{
1008        int prev_state;
1009
1010        mutex_lock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1011        /* Nothing to be done here */
1012        if (tg_pt_gp->tg_pt_gp_alua_access_state == new_state) {
1013                mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1014                return 0;
1015        }
1016
1017        if (explicit && new_state == ALUA_ACCESS_STATE_TRANSITION) {
1018                mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1019                return -EAGAIN;
1020        }
1021
1022        /*
1023         * Save the old primary ALUA access state, and set the current state
1024         * to ALUA_ACCESS_STATE_TRANSITION.
1025         */
1026        prev_state = tg_pt_gp->tg_pt_gp_alua_access_state;
1027        tg_pt_gp->tg_pt_gp_alua_access_state = ALUA_ACCESS_STATE_TRANSITION;
1028        tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
1029                                ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1030                                ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1031
1032        core_alua_queue_state_change_ua(tg_pt_gp);
1033
1034        if (new_state == ALUA_ACCESS_STATE_TRANSITION) {
1035                mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1036                return 0;
1037        }
1038
1039        /*
1040         * Check for the optional ALUA primary state transition delay
1041         */
1042        if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
1043                msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1044
1045        /*
1046         * Set the current primary ALUA access state to the requested new state
1047         */
1048        tg_pt_gp->tg_pt_gp_alua_access_state = new_state;
1049
1050        /*
1051         * Update the ALUA metadata buf that has been allocated in
1052         * core_alua_do_port_transition(), this metadata will be written
1053         * to struct file.
1054         *
1055         * Note that there is the case where we do not want to update the
1056         * metadata when the saved metadata is being parsed in userspace
1057         * when setting the existing port access state and access status.
1058         *
1059         * Also note that the failure to write out the ALUA metadata to
1060         * struct file does NOT affect the actual ALUA transition.
1061         */
1062        if (tg_pt_gp->tg_pt_gp_write_metadata) {
1063                core_alua_update_tpg_primary_metadata(tg_pt_gp);
1064        }
1065
1066        pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1067                " from primary access state %s to %s\n", (explicit) ? "explicit" :
1068                "implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1069                tg_pt_gp->tg_pt_gp_id,
1070                core_alua_dump_state(prev_state),
1071                core_alua_dump_state(new_state));
1072
1073        core_alua_queue_state_change_ua(tg_pt_gp);
1074
1075        mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1076        return 0;
1077}
1078
1079int core_alua_do_port_transition(
1080        struct t10_alua_tg_pt_gp *l_tg_pt_gp,
1081        struct se_device *l_dev,
1082        struct se_lun *l_lun,
1083        struct se_node_acl *l_nacl,
1084        int new_state,
1085        int explicit)
1086{
1087        struct se_device *dev;
1088        struct t10_alua_lu_gp *lu_gp;
1089        struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
1090        struct t10_alua_tg_pt_gp *tg_pt_gp;
1091        int primary, valid_states, rc = 0;
1092
1093        if (l_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
1094                return -ENODEV;
1095
1096        valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
1097        if (core_alua_check_transition(new_state, valid_states, &primary,
1098                                       explicit) != 0)
1099                return -EINVAL;
1100
1101        local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
1102        spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
1103        lu_gp = local_lu_gp_mem->lu_gp;
1104        atomic_inc(&lu_gp->lu_gp_ref_cnt);
1105        spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
1106        /*
1107         * For storage objects that are members of the 'default_lu_gp',
1108         * we only do transition on the passed *l_tp_pt_gp, and not
1109         * on all of the matching target port groups IDs in default_lu_gp.
1110         */
1111        if (!lu_gp->lu_gp_id) {
1112                /*
1113                 * core_alua_do_transition_tg_pt() will always return
1114                 * success.
1115                 */
1116                l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1117                l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1118                rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
1119                                                   new_state, explicit);
1120                atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1121                return rc;
1122        }
1123        /*
1124         * For all other LU groups aside from 'default_lu_gp', walk all of
1125         * the associated storage objects looking for a matching target port
1126         * group ID from the local target port group.
1127         */
1128        spin_lock(&lu_gp->lu_gp_lock);
1129        list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
1130                                lu_gp_mem_list) {
1131
1132                dev = lu_gp_mem->lu_gp_mem_dev;
1133                atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1134                spin_unlock(&lu_gp->lu_gp_lock);
1135
1136                spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1137                list_for_each_entry(tg_pt_gp,
1138                                &dev->t10_alua.tg_pt_gps_list,
1139                                tg_pt_gp_list) {
1140
1141                        if (!tg_pt_gp->tg_pt_gp_valid_id)
1142                                continue;
1143                        /*
1144                         * If the target behavior port asymmetric access state
1145                         * is changed for any target port group accessible via
1146                         * a logical unit within a LU group, the target port
1147                         * behavior group asymmetric access states for the same
1148                         * target port group accessible via other logical units
1149                         * in that LU group will also change.
1150                         */
1151                        if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
1152                                continue;
1153
1154                        if (l_tg_pt_gp == tg_pt_gp) {
1155                                tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1156                                tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1157                        } else {
1158                                tg_pt_gp->tg_pt_gp_alua_lun = NULL;
1159                                tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
1160                        }
1161                        atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1162                        spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1163                        /*
1164                         * core_alua_do_transition_tg_pt() will always return
1165                         * success.
1166                         */
1167                        rc = core_alua_do_transition_tg_pt(tg_pt_gp,
1168                                        new_state, explicit);
1169
1170                        spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1171                        atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1172                        if (rc)
1173                                break;
1174                }
1175                spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1176
1177                spin_lock(&lu_gp->lu_gp_lock);
1178                atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1179        }
1180        spin_unlock(&lu_gp->lu_gp_lock);
1181
1182        if (!rc) {
1183                pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1184                         " Group IDs: %hu %s transition to primary state: %s\n",
1185                         config_item_name(&lu_gp->lu_gp_group.cg_item),
1186                         l_tg_pt_gp->tg_pt_gp_id,
1187                         (explicit) ? "explicit" : "implicit",
1188                         core_alua_dump_state(new_state));
1189        }
1190
1191        atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1192        return rc;
1193}
1194
1195static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
1196{
1197        struct se_portal_group *se_tpg = lun->lun_tpg;
1198        unsigned char *md_buf;
1199        char *path;
1200        int len, rc;
1201
1202        mutex_lock(&lun->lun_tg_pt_md_mutex);
1203
1204        md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
1205        if (!md_buf) {
1206                pr_err("Unable to allocate buf for ALUA metadata\n");
1207                rc = -ENOMEM;
1208                goto out_unlock;
1209        }
1210
1211        len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
1212                        "alua_tg_pt_status=0x%02x\n",
1213                        atomic_read(&lun->lun_tg_pt_secondary_offline),
1214                        lun->lun_tg_pt_secondary_stat);
1215
1216        if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL) {
1217                path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s+%hu/lun_%llu",
1218                                db_root, se_tpg->se_tpg_tfo->fabric_name,
1219                                se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1220                                se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg),
1221                                lun->unpacked_lun);
1222        } else {
1223                path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s/lun_%llu",
1224                                db_root, se_tpg->se_tpg_tfo->fabric_name,
1225                                se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1226                                lun->unpacked_lun);
1227        }
1228        if (!path) {
1229                rc = -ENOMEM;
1230                goto out_free;
1231        }
1232
1233        rc = core_alua_write_tpg_metadata(path, md_buf, len);
1234        kfree(path);
1235out_free:
1236        kfree(md_buf);
1237out_unlock:
1238        mutex_unlock(&lun->lun_tg_pt_md_mutex);
1239        return rc;
1240}
1241
1242static int core_alua_set_tg_pt_secondary_state(
1243        struct se_lun *lun,
1244        int explicit,
1245        int offline)
1246{
1247        struct t10_alua_tg_pt_gp *tg_pt_gp;
1248        int trans_delay_msecs;
1249
1250        spin_lock(&lun->lun_tg_pt_gp_lock);
1251        tg_pt_gp = lun->lun_tg_pt_gp;
1252        if (!tg_pt_gp) {
1253                spin_unlock(&lun->lun_tg_pt_gp_lock);
1254                pr_err("Unable to complete secondary state"
1255                                " transition\n");
1256                return -EINVAL;
1257        }
1258        trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1259        /*
1260         * Set the secondary ALUA target port access state to OFFLINE
1261         * or release the previously secondary state for struct se_lun
1262         */
1263        if (offline)
1264                atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
1265        else
1266                atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
1267
1268        lun->lun_tg_pt_secondary_stat = (explicit) ?
1269                        ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1270                        ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1271
1272        pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1273                " to secondary access state: %s\n", (explicit) ? "explicit" :
1274                "implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1275                tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1276
1277        spin_unlock(&lun->lun_tg_pt_gp_lock);
1278        /*
1279         * Do the optional transition delay after we set the secondary
1280         * ALUA access state.
1281         */
1282        if (trans_delay_msecs != 0)
1283                msleep_interruptible(trans_delay_msecs);
1284        /*
1285         * See if we need to update the ALUA fabric port metadata for
1286         * secondary state and status
1287         */
1288        if (lun->lun_tg_pt_secondary_write_md)
1289                core_alua_update_tpg_secondary_metadata(lun);
1290
1291        return 0;
1292}
1293
1294struct t10_alua_lba_map *
1295core_alua_allocate_lba_map(struct list_head *list,
1296                           u64 first_lba, u64 last_lba)
1297{
1298        struct t10_alua_lba_map *lba_map;
1299
1300        lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
1301        if (!lba_map) {
1302                pr_err("Unable to allocate struct t10_alua_lba_map\n");
1303                return ERR_PTR(-ENOMEM);
1304        }
1305        INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
1306        lba_map->lba_map_first_lba = first_lba;
1307        lba_map->lba_map_last_lba = last_lba;
1308
1309        list_add_tail(&lba_map->lba_map_list, list);
1310        return lba_map;
1311}
1312
1313int
1314core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
1315                               int pg_id, int state)
1316{
1317        struct t10_alua_lba_map_member *lba_map_mem;
1318
1319        list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
1320                            lba_map_mem_list) {
1321                if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
1322                        pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
1323                        return -EINVAL;
1324                }
1325        }
1326
1327        lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
1328        if (!lba_map_mem) {
1329                pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
1330                return -ENOMEM;
1331        }
1332        lba_map_mem->lba_map_mem_alua_state = state;
1333        lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
1334
1335        list_add_tail(&lba_map_mem->lba_map_mem_list,
1336                      &lba_map->lba_map_mem_list);
1337        return 0;
1338}
1339
1340void
1341core_alua_free_lba_map(struct list_head *lba_list)
1342{
1343        struct t10_alua_lba_map *lba_map, *lba_map_tmp;
1344        struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
1345
1346        list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
1347                                 lba_map_list) {
1348                list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
1349                                         &lba_map->lba_map_mem_list,
1350                                         lba_map_mem_list) {
1351                        list_del(&lba_map_mem->lba_map_mem_list);
1352                        kmem_cache_free(t10_alua_lba_map_mem_cache,
1353                                        lba_map_mem);
1354                }
1355                list_del(&lba_map->lba_map_list);
1356                kmem_cache_free(t10_alua_lba_map_cache, lba_map);
1357        }
1358}
1359
1360void
1361core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
1362                      int segment_size, int segment_mult)
1363{
1364        struct list_head old_lba_map_list;
1365        struct t10_alua_tg_pt_gp *tg_pt_gp;
1366        int activate = 0, supported;
1367
1368        INIT_LIST_HEAD(&old_lba_map_list);
1369        spin_lock(&dev->t10_alua.lba_map_lock);
1370        dev->t10_alua.lba_map_segment_size = segment_size;
1371        dev->t10_alua.lba_map_segment_multiplier = segment_mult;
1372        list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
1373        if (lba_map_list) {
1374                list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
1375                activate = 1;
1376        }
1377        spin_unlock(&dev->t10_alua.lba_map_lock);
1378        spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1379        list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1380                            tg_pt_gp_list) {
1381
1382                if (!tg_pt_gp->tg_pt_gp_valid_id)
1383                        continue;
1384                supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
1385                if (activate)
1386                        supported |= ALUA_LBD_SUP;
1387                else
1388                        supported &= ~ALUA_LBD_SUP;
1389                tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
1390        }
1391        spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1392        core_alua_free_lba_map(&old_lba_map_list);
1393}
1394
1395struct t10_alua_lu_gp *
1396core_alua_allocate_lu_gp(const char *name, int def_group)
1397{
1398        struct t10_alua_lu_gp *lu_gp;
1399
1400        lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1401        if (!lu_gp) {
1402                pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1403                return ERR_PTR(-ENOMEM);
1404        }
1405        INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1406        INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1407        spin_lock_init(&lu_gp->lu_gp_lock);
1408        atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1409
1410        if (def_group) {
1411                lu_gp->lu_gp_id = alua_lu_gps_counter++;
1412                lu_gp->lu_gp_valid_id = 1;
1413                alua_lu_gps_count++;
1414        }
1415
1416        return lu_gp;
1417}
1418
1419int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1420{
1421        struct t10_alua_lu_gp *lu_gp_tmp;
1422        u16 lu_gp_id_tmp;
1423        /*
1424         * The lu_gp->lu_gp_id may only be set once..
1425         */
1426        if (lu_gp->lu_gp_valid_id) {
1427                pr_warn("ALUA LU Group already has a valid ID,"
1428                        " ignoring request\n");
1429                return -EINVAL;
1430        }
1431
1432        spin_lock(&lu_gps_lock);
1433        if (alua_lu_gps_count == 0x0000ffff) {
1434                pr_err("Maximum ALUA alua_lu_gps_count:"
1435                                " 0x0000ffff reached\n");
1436                spin_unlock(&lu_gps_lock);
1437                kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1438                return -ENOSPC;
1439        }
1440again:
1441        lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1442                                alua_lu_gps_counter++;
1443
1444        list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1445                if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1446                        if (!lu_gp_id)
1447                                goto again;
1448
1449                        pr_warn("ALUA Logical Unit Group ID: %hu"
1450                                " already exists, ignoring request\n",
1451                                lu_gp_id);
1452                        spin_unlock(&lu_gps_lock);
1453                        return -EINVAL;
1454                }
1455        }
1456
1457        lu_gp->lu_gp_id = lu_gp_id_tmp;
1458        lu_gp->lu_gp_valid_id = 1;
1459        list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1460        alua_lu_gps_count++;
1461        spin_unlock(&lu_gps_lock);
1462
1463        return 0;
1464}
1465
1466static struct t10_alua_lu_gp_member *
1467core_alua_allocate_lu_gp_mem(struct se_device *dev)
1468{
1469        struct t10_alua_lu_gp_member *lu_gp_mem;
1470
1471        lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1472        if (!lu_gp_mem) {
1473                pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1474                return ERR_PTR(-ENOMEM);
1475        }
1476        INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1477        spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1478        atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1479
1480        lu_gp_mem->lu_gp_mem_dev = dev;
1481        dev->dev_alua_lu_gp_mem = lu_gp_mem;
1482
1483        return lu_gp_mem;
1484}
1485
1486void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1487{
1488        struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1489        /*
1490         * Once we have reached this point, config_item_put() has
1491         * already been called from target_core_alua_drop_lu_gp().
1492         *
1493         * Here, we remove the *lu_gp from the global list so that
1494         * no associations can be made while we are releasing
1495         * struct t10_alua_lu_gp.
1496         */
1497        spin_lock(&lu_gps_lock);
1498        list_del(&lu_gp->lu_gp_node);
1499        alua_lu_gps_count--;
1500        spin_unlock(&lu_gps_lock);
1501        /*
1502         * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1503         * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1504         * released with core_alua_put_lu_gp_from_name()
1505         */
1506        while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1507                cpu_relax();
1508        /*
1509         * Release reference to struct t10_alua_lu_gp * from all associated
1510         * struct se_device.
1511         */
1512        spin_lock(&lu_gp->lu_gp_lock);
1513        list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1514                                &lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1515                if (lu_gp_mem->lu_gp_assoc) {
1516                        list_del(&lu_gp_mem->lu_gp_mem_list);
1517                        lu_gp->lu_gp_members--;
1518                        lu_gp_mem->lu_gp_assoc = 0;
1519                }
1520                spin_unlock(&lu_gp->lu_gp_lock);
1521                /*
1522                 *
1523                 * lu_gp_mem is associated with a single
1524                 * struct se_device->dev_alua_lu_gp_mem, and is released when
1525                 * struct se_device is released via core_alua_free_lu_gp_mem().
1526                 *
1527                 * If the passed lu_gp does NOT match the default_lu_gp, assume
1528                 * we want to re-associate a given lu_gp_mem with default_lu_gp.
1529                 */
1530                spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1531                if (lu_gp != default_lu_gp)
1532                        __core_alua_attach_lu_gp_mem(lu_gp_mem,
1533                                        default_lu_gp);
1534                else
1535                        lu_gp_mem->lu_gp = NULL;
1536                spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1537
1538                spin_lock(&lu_gp->lu_gp_lock);
1539        }
1540        spin_unlock(&lu_gp->lu_gp_lock);
1541
1542        kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1543}
1544
1545void core_alua_free_lu_gp_mem(struct se_device *dev)
1546{
1547        struct t10_alua_lu_gp *lu_gp;
1548        struct t10_alua_lu_gp_member *lu_gp_mem;
1549
1550        lu_gp_mem = dev->dev_alua_lu_gp_mem;
1551        if (!lu_gp_mem)
1552                return;
1553
1554        while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1555                cpu_relax();
1556
1557        spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1558        lu_gp = lu_gp_mem->lu_gp;
1559        if (lu_gp) {
1560                spin_lock(&lu_gp->lu_gp_lock);
1561                if (lu_gp_mem->lu_gp_assoc) {
1562                        list_del(&lu_gp_mem->lu_gp_mem_list);
1563                        lu_gp->lu_gp_members--;
1564                        lu_gp_mem->lu_gp_assoc = 0;
1565                }
1566                spin_unlock(&lu_gp->lu_gp_lock);
1567                lu_gp_mem->lu_gp = NULL;
1568        }
1569        spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1570
1571        kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1572}
1573
1574struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1575{
1576        struct t10_alua_lu_gp *lu_gp;
1577        struct config_item *ci;
1578
1579        spin_lock(&lu_gps_lock);
1580        list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1581                if (!lu_gp->lu_gp_valid_id)
1582                        continue;
1583                ci = &lu_gp->lu_gp_group.cg_item;
1584                if (!strcmp(config_item_name(ci), name)) {
1585                        atomic_inc(&lu_gp->lu_gp_ref_cnt);
1586                        spin_unlock(&lu_gps_lock);
1587                        return lu_gp;
1588                }
1589        }
1590        spin_unlock(&lu_gps_lock);
1591
1592        return NULL;
1593}
1594
1595void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1596{
1597        spin_lock(&lu_gps_lock);
1598        atomic_dec(&lu_gp->lu_gp_ref_cnt);
1599        spin_unlock(&lu_gps_lock);
1600}
1601
1602/*
1603 * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1604 */
1605void __core_alua_attach_lu_gp_mem(
1606        struct t10_alua_lu_gp_member *lu_gp_mem,
1607        struct t10_alua_lu_gp *lu_gp)
1608{
1609        spin_lock(&lu_gp->lu_gp_lock);
1610        lu_gp_mem->lu_gp = lu_gp;
1611        lu_gp_mem->lu_gp_assoc = 1;
1612        list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1613        lu_gp->lu_gp_members++;
1614        spin_unlock(&lu_gp->lu_gp_lock);
1615}
1616
1617/*
1618 * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1619 */
1620void __core_alua_drop_lu_gp_mem(
1621        struct t10_alua_lu_gp_member *lu_gp_mem,
1622        struct t10_alua_lu_gp *lu_gp)
1623{
1624        spin_lock(&lu_gp->lu_gp_lock);
1625        list_del(&lu_gp_mem->lu_gp_mem_list);
1626        lu_gp_mem->lu_gp = NULL;
1627        lu_gp_mem->lu_gp_assoc = 0;
1628        lu_gp->lu_gp_members--;
1629        spin_unlock(&lu_gp->lu_gp_lock);
1630}
1631
1632struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1633                const char *name, int def_group)
1634{
1635        struct t10_alua_tg_pt_gp *tg_pt_gp;
1636
1637        tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1638        if (!tg_pt_gp) {
1639                pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1640                return NULL;
1641        }
1642        INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1643        INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
1644        mutex_init(&tg_pt_gp->tg_pt_gp_transition_mutex);
1645        spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1646        atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1647        tg_pt_gp->tg_pt_gp_dev = dev;
1648        tg_pt_gp->tg_pt_gp_alua_access_state =
1649                        ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED;
1650        /*
1651         * Enable both explicit and implicit ALUA support by default
1652         */
1653        tg_pt_gp->tg_pt_gp_alua_access_type =
1654                        TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
1655        /*
1656         * Set the default Active/NonOptimized Delay in milliseconds
1657         */
1658        tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1659        tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1660        tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
1661
1662        /*
1663         * Enable all supported states
1664         */
1665        tg_pt_gp->tg_pt_gp_alua_supported_states =
1666            ALUA_T_SUP | ALUA_O_SUP |
1667            ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
1668
1669        if (def_group) {
1670                spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1671                tg_pt_gp->tg_pt_gp_id =
1672                                dev->t10_alua.alua_tg_pt_gps_counter++;
1673                tg_pt_gp->tg_pt_gp_valid_id = 1;
1674                dev->t10_alua.alua_tg_pt_gps_count++;
1675                list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1676                              &dev->t10_alua.tg_pt_gps_list);
1677                spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1678        }
1679
1680        return tg_pt_gp;
1681}
1682
1683int core_alua_set_tg_pt_gp_id(
1684        struct t10_alua_tg_pt_gp *tg_pt_gp,
1685        u16 tg_pt_gp_id)
1686{
1687        struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1688        struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1689        u16 tg_pt_gp_id_tmp;
1690
1691        /*
1692         * The tg_pt_gp->tg_pt_gp_id may only be set once..
1693         */
1694        if (tg_pt_gp->tg_pt_gp_valid_id) {
1695                pr_warn("ALUA TG PT Group already has a valid ID,"
1696                        " ignoring request\n");
1697                return -EINVAL;
1698        }
1699
1700        spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1701        if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1702                pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1703                        " 0x0000ffff reached\n");
1704                spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1705                kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1706                return -ENOSPC;
1707        }
1708again:
1709        tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1710                        dev->t10_alua.alua_tg_pt_gps_counter++;
1711
1712        list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1713                        tg_pt_gp_list) {
1714                if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1715                        if (!tg_pt_gp_id)
1716                                goto again;
1717
1718                        pr_err("ALUA Target Port Group ID: %hu already"
1719                                " exists, ignoring request\n", tg_pt_gp_id);
1720                        spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1721                        return -EINVAL;
1722                }
1723        }
1724
1725        tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1726        tg_pt_gp->tg_pt_gp_valid_id = 1;
1727        list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1728                        &dev->t10_alua.tg_pt_gps_list);
1729        dev->t10_alua.alua_tg_pt_gps_count++;
1730        spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1731
1732        return 0;
1733}
1734
1735void core_alua_free_tg_pt_gp(
1736        struct t10_alua_tg_pt_gp *tg_pt_gp)
1737{
1738        struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1739        struct se_lun *lun, *next;
1740
1741        /*
1742         * Once we have reached this point, config_item_put() has already
1743         * been called from target_core_alua_drop_tg_pt_gp().
1744         *
1745         * Here we remove *tg_pt_gp from the global list so that
1746         * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
1747         * can be made while we are releasing struct t10_alua_tg_pt_gp.
1748         */
1749        spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1750        if (tg_pt_gp->tg_pt_gp_valid_id) {
1751                list_del(&tg_pt_gp->tg_pt_gp_list);
1752                dev->t10_alua.alua_tg_pt_gps_count--;
1753        }
1754        spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1755
1756        /*
1757         * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1758         * core_alua_get_tg_pt_gp_by_name() in
1759         * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1760         * to be released with core_alua_put_tg_pt_gp_from_name().
1761         */
1762        while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1763                cpu_relax();
1764
1765        /*
1766         * Release reference to struct t10_alua_tg_pt_gp from all associated
1767         * struct se_port.
1768         */
1769        spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1770        list_for_each_entry_safe(lun, next,
1771                        &tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
1772                list_del_init(&lun->lun_tg_pt_gp_link);
1773                tg_pt_gp->tg_pt_gp_members--;
1774
1775                spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1776                /*
1777                 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1778                 * assume we want to re-associate a given tg_pt_gp_mem with
1779                 * default_tg_pt_gp.
1780                 */
1781                spin_lock(&lun->lun_tg_pt_gp_lock);
1782                if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1783                        __target_attach_tg_pt_gp(lun,
1784                                        dev->t10_alua.default_tg_pt_gp);
1785                } else
1786                        lun->lun_tg_pt_gp = NULL;
1787                spin_unlock(&lun->lun_tg_pt_gp_lock);
1788
1789                spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1790        }
1791        spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1792
1793        kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1794}
1795
1796static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1797                struct se_device *dev, const char *name)
1798{
1799        struct t10_alua_tg_pt_gp *tg_pt_gp;
1800        struct config_item *ci;
1801
1802        spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1803        list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1804                        tg_pt_gp_list) {
1805                if (!tg_pt_gp->tg_pt_gp_valid_id)
1806                        continue;
1807                ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1808                if (!strcmp(config_item_name(ci), name)) {
1809                        atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1810                        spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1811                        return tg_pt_gp;
1812                }
1813        }
1814        spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1815
1816        return NULL;
1817}
1818
1819static void core_alua_put_tg_pt_gp_from_name(
1820        struct t10_alua_tg_pt_gp *tg_pt_gp)
1821{
1822        struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1823
1824        spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1825        atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1826        spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1827}
1828
1829static void __target_attach_tg_pt_gp(struct se_lun *lun,
1830                struct t10_alua_tg_pt_gp *tg_pt_gp)
1831{
1832        struct se_dev_entry *se_deve;
1833
1834        assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1835
1836        spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1837        lun->lun_tg_pt_gp = tg_pt_gp;
1838        list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
1839        tg_pt_gp->tg_pt_gp_members++;
1840        spin_lock(&lun->lun_deve_lock);
1841        list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
1842                core_scsi3_ua_allocate(se_deve, 0x3f,
1843                                       ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
1844        spin_unlock(&lun->lun_deve_lock);
1845        spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1846}
1847
1848void target_attach_tg_pt_gp(struct se_lun *lun,
1849                struct t10_alua_tg_pt_gp *tg_pt_gp)
1850{
1851        spin_lock(&lun->lun_tg_pt_gp_lock);
1852        __target_attach_tg_pt_gp(lun, tg_pt_gp);
1853        spin_unlock(&lun->lun_tg_pt_gp_lock);
1854}
1855
1856static void __target_detach_tg_pt_gp(struct se_lun *lun,
1857                struct t10_alua_tg_pt_gp *tg_pt_gp)
1858{
1859        assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1860
1861        spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1862        list_del_init(&lun->lun_tg_pt_gp_link);
1863        tg_pt_gp->tg_pt_gp_members--;
1864        spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1865
1866        lun->lun_tg_pt_gp = NULL;
1867}
1868
1869void target_detach_tg_pt_gp(struct se_lun *lun)
1870{
1871        struct t10_alua_tg_pt_gp *tg_pt_gp;
1872
1873        spin_lock(&lun->lun_tg_pt_gp_lock);
1874        tg_pt_gp = lun->lun_tg_pt_gp;
1875        if (tg_pt_gp)
1876                __target_detach_tg_pt_gp(lun, tg_pt_gp);
1877        spin_unlock(&lun->lun_tg_pt_gp_lock);
1878}
1879
1880ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
1881{
1882        struct config_item *tg_pt_ci;
1883        struct t10_alua_tg_pt_gp *tg_pt_gp;
1884        ssize_t len = 0;
1885
1886        spin_lock(&lun->lun_tg_pt_gp_lock);
1887        tg_pt_gp = lun->lun_tg_pt_gp;
1888        if (tg_pt_gp) {
1889                tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1890                len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1891                        " %hu\nTG Port Primary Access State: %s\nTG Port "
1892                        "Primary Access Status: %s\nTG Port Secondary Access"
1893                        " State: %s\nTG Port Secondary Access Status: %s\n",
1894                        config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1895                        core_alua_dump_state(
1896                                tg_pt_gp->tg_pt_gp_alua_access_state),
1897                        core_alua_dump_status(
1898                                tg_pt_gp->tg_pt_gp_alua_access_status),
1899                        atomic_read(&lun->lun_tg_pt_secondary_offline) ?
1900                        "Offline" : "None",
1901                        core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
1902        }
1903        spin_unlock(&lun->lun_tg_pt_gp_lock);
1904
1905        return len;
1906}
1907
1908ssize_t core_alua_store_tg_pt_gp_info(
1909        struct se_lun *lun,
1910        const char *page,
1911        size_t count)
1912{
1913        struct se_portal_group *tpg = lun->lun_tpg;
1914        /*
1915         * rcu_dereference_raw protected by se_lun->lun_group symlink
1916         * reference to se_device->dev_group.
1917         */
1918        struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
1919        struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1920        unsigned char buf[TG_PT_GROUP_NAME_BUF];
1921        int move = 0;
1922
1923        if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
1924            (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
1925                return -ENODEV;
1926
1927        if (count > TG_PT_GROUP_NAME_BUF) {
1928                pr_err("ALUA Target Port Group alias too large!\n");
1929                return -EINVAL;
1930        }
1931        memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1932        memcpy(buf, page, count);
1933        /*
1934         * Any ALUA target port group alias besides "NULL" means we will be
1935         * making a new group association.
1936         */
1937        if (strcmp(strstrip(buf), "NULL")) {
1938                /*
1939                 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1940                 * struct t10_alua_tg_pt_gp.  This reference is released with
1941                 * core_alua_put_tg_pt_gp_from_name() below.
1942                 */
1943                tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1944                                        strstrip(buf));
1945                if (!tg_pt_gp_new)
1946                        return -ENODEV;
1947        }
1948
1949        spin_lock(&lun->lun_tg_pt_gp_lock);
1950        tg_pt_gp = lun->lun_tg_pt_gp;
1951        if (tg_pt_gp) {
1952                /*
1953                 * Clearing an existing tg_pt_gp association, and replacing
1954                 * with the default_tg_pt_gp.
1955                 */
1956                if (!tg_pt_gp_new) {
1957                        pr_debug("Target_Core_ConfigFS: Moving"
1958                                " %s/tpgt_%hu/%s from ALUA Target Port Group:"
1959                                " alua/%s, ID: %hu back to"
1960                                " default_tg_pt_gp\n",
1961                                tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1962                                tpg->se_tpg_tfo->tpg_get_tag(tpg),
1963                                config_item_name(&lun->lun_group.cg_item),
1964                                config_item_name(
1965                                        &tg_pt_gp->tg_pt_gp_group.cg_item),
1966                                tg_pt_gp->tg_pt_gp_id);
1967
1968                        __target_detach_tg_pt_gp(lun, tg_pt_gp);
1969                        __target_attach_tg_pt_gp(lun,
1970                                        dev->t10_alua.default_tg_pt_gp);
1971                        spin_unlock(&lun->lun_tg_pt_gp_lock);
1972
1973                        return count;
1974                }
1975                __target_detach_tg_pt_gp(lun, tg_pt_gp);
1976                move = 1;
1977        }
1978
1979        __target_attach_tg_pt_gp(lun, tg_pt_gp_new);
1980        spin_unlock(&lun->lun_tg_pt_gp_lock);
1981        pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1982                " Target Port Group: alua/%s, ID: %hu\n", (move) ?
1983                "Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1984                tpg->se_tpg_tfo->tpg_get_tag(tpg),
1985                config_item_name(&lun->lun_group.cg_item),
1986                config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1987                tg_pt_gp_new->tg_pt_gp_id);
1988
1989        core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1990        return count;
1991}
1992
1993ssize_t core_alua_show_access_type(
1994        struct t10_alua_tg_pt_gp *tg_pt_gp,
1995        char *page)
1996{
1997        if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
1998            (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
1999                return sprintf(page, "Implicit and Explicit\n");
2000        else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
2001                return sprintf(page, "Implicit\n");
2002        else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
2003                return sprintf(page, "Explicit\n");
2004        else
2005                return sprintf(page, "None\n");
2006}
2007
2008ssize_t core_alua_store_access_type(
2009        struct t10_alua_tg_pt_gp *tg_pt_gp,
2010        const char *page,
2011        size_t count)
2012{
2013        unsigned long tmp;
2014        int ret;
2015
2016        ret = kstrtoul(page, 0, &tmp);
2017        if (ret < 0) {
2018                pr_err("Unable to extract alua_access_type\n");
2019                return ret;
2020        }
2021        if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
2022                pr_err("Illegal value for alua_access_type:"
2023                                " %lu\n", tmp);
2024                return -EINVAL;
2025        }
2026        if (tmp == 3)
2027                tg_pt_gp->tg_pt_gp_alua_access_type =
2028                        TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
2029        else if (tmp == 2)
2030                tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
2031        else if (tmp == 1)
2032                tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
2033        else
2034                tg_pt_gp->tg_pt_gp_alua_access_type = 0;
2035
2036        return count;
2037}
2038
2039ssize_t core_alua_show_nonop_delay_msecs(
2040        struct t10_alua_tg_pt_gp *tg_pt_gp,
2041        char *page)
2042{
2043        return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
2044}
2045
2046ssize_t core_alua_store_nonop_delay_msecs(
2047        struct t10_alua_tg_pt_gp *tg_pt_gp,
2048        const char *page,
2049        size_t count)
2050{
2051        unsigned long tmp;
2052        int ret;
2053
2054        ret = kstrtoul(page, 0, &tmp);
2055        if (ret < 0) {
2056                pr_err("Unable to extract nonop_delay_msecs\n");
2057                return ret;
2058        }
2059        if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
2060                pr_err("Passed nonop_delay_msecs: %lu, exceeds"
2061                        " ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
2062                        ALUA_MAX_NONOP_DELAY_MSECS);
2063                return -EINVAL;
2064        }
2065        tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
2066
2067        return count;
2068}
2069
2070ssize_t core_alua_show_trans_delay_msecs(
2071        struct t10_alua_tg_pt_gp *tg_pt_gp,
2072        char *page)
2073{
2074        return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
2075}
2076
2077ssize_t core_alua_store_trans_delay_msecs(
2078        struct t10_alua_tg_pt_gp *tg_pt_gp,
2079        const char *page,
2080        size_t count)
2081{
2082        unsigned long tmp;
2083        int ret;
2084
2085        ret = kstrtoul(page, 0, &tmp);
2086        if (ret < 0) {
2087                pr_err("Unable to extract trans_delay_msecs\n");
2088                return ret;
2089        }
2090        if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
2091                pr_err("Passed trans_delay_msecs: %lu, exceeds"
2092                        " ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
2093                        ALUA_MAX_TRANS_DELAY_MSECS);
2094                return -EINVAL;
2095        }
2096        tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
2097
2098        return count;
2099}
2100
2101ssize_t core_alua_show_implicit_trans_secs(
2102        struct t10_alua_tg_pt_gp *tg_pt_gp,
2103        char *page)
2104{
2105        return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
2106}
2107
2108ssize_t core_alua_store_implicit_trans_secs(
2109        struct t10_alua_tg_pt_gp *tg_pt_gp,
2110        const char *page,
2111        size_t count)
2112{
2113        unsigned long tmp;
2114        int ret;
2115
2116        ret = kstrtoul(page, 0, &tmp);
2117        if (ret < 0) {
2118                pr_err("Unable to extract implicit_trans_secs\n");
2119                return ret;
2120        }
2121        if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
2122                pr_err("Passed implicit_trans_secs: %lu, exceeds"
2123                        " ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
2124                        ALUA_MAX_IMPLICIT_TRANS_SECS);
2125                return  -EINVAL;
2126        }
2127        tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
2128
2129        return count;
2130}
2131
2132ssize_t core_alua_show_preferred_bit(
2133        struct t10_alua_tg_pt_gp *tg_pt_gp,
2134        char *page)
2135{
2136        return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
2137}
2138
2139ssize_t core_alua_store_preferred_bit(
2140        struct t10_alua_tg_pt_gp *tg_pt_gp,
2141        const char *page,
2142        size_t count)
2143{
2144        unsigned long tmp;
2145        int ret;
2146
2147        ret = kstrtoul(page, 0, &tmp);
2148        if (ret < 0) {
2149                pr_err("Unable to extract preferred ALUA value\n");
2150                return ret;
2151        }
2152        if ((tmp != 0) && (tmp != 1)) {
2153                pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
2154                return -EINVAL;
2155        }
2156        tg_pt_gp->tg_pt_gp_pref = (int)tmp;
2157
2158        return count;
2159}
2160
2161ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
2162{
2163        return sprintf(page, "%d\n",
2164                atomic_read(&lun->lun_tg_pt_secondary_offline));
2165}
2166
2167ssize_t core_alua_store_offline_bit(
2168        struct se_lun *lun,
2169        const char *page,
2170        size_t count)
2171{
2172        /*
2173         * rcu_dereference_raw protected by se_lun->lun_group symlink
2174         * reference to se_device->dev_group.
2175         */
2176        struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
2177        unsigned long tmp;
2178        int ret;
2179
2180        if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
2181            (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
2182                return -ENODEV;
2183
2184        ret = kstrtoul(page, 0, &tmp);
2185        if (ret < 0) {
2186                pr_err("Unable to extract alua_tg_pt_offline value\n");
2187                return ret;
2188        }
2189        if ((tmp != 0) && (tmp != 1)) {
2190                pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
2191                                tmp);
2192                return -EINVAL;
2193        }
2194
2195        ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
2196        if (ret < 0)
2197                return -EINVAL;
2198
2199        return count;
2200}
2201
2202ssize_t core_alua_show_secondary_status(
2203        struct se_lun *lun,
2204        char *page)
2205{
2206        return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
2207}
2208
2209ssize_t core_alua_store_secondary_status(
2210        struct se_lun *lun,
2211        const char *page,
2212        size_t count)
2213{
2214        unsigned long tmp;
2215        int ret;
2216
2217        ret = kstrtoul(page, 0, &tmp);
2218        if (ret < 0) {
2219                pr_err("Unable to extract alua_tg_pt_status\n");
2220                return ret;
2221        }
2222        if ((tmp != ALUA_STATUS_NONE) &&
2223            (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
2224            (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
2225                pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2226                                tmp);
2227                return -EINVAL;
2228        }
2229        lun->lun_tg_pt_secondary_stat = (int)tmp;
2230
2231        return count;
2232}
2233
2234ssize_t core_alua_show_secondary_write_metadata(
2235        struct se_lun *lun,
2236        char *page)
2237{
2238        return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
2239}
2240
2241ssize_t core_alua_store_secondary_write_metadata(
2242        struct se_lun *lun,
2243        const char *page,
2244        size_t count)
2245{
2246        unsigned long tmp;
2247        int ret;
2248
2249        ret = kstrtoul(page, 0, &tmp);
2250        if (ret < 0) {
2251                pr_err("Unable to extract alua_tg_pt_write_md\n");
2252                return ret;
2253        }
2254        if ((tmp != 0) && (tmp != 1)) {
2255                pr_err("Illegal value for alua_tg_pt_write_md:"
2256                                " %lu\n", tmp);
2257                return -EINVAL;
2258        }
2259        lun->lun_tg_pt_secondary_write_md = (int)tmp;
2260
2261        return count;
2262}
2263
2264int core_setup_alua(struct se_device *dev)
2265{
2266        if (!(dev->transport_flags &
2267             TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
2268            !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2269                struct t10_alua_lu_gp_member *lu_gp_mem;
2270
2271                /*
2272                 * Associate this struct se_device with the default ALUA
2273                 * LUN Group.
2274                 */
2275                lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2276                if (IS_ERR(lu_gp_mem))
2277                        return PTR_ERR(lu_gp_mem);
2278
2279                spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2280                __core_alua_attach_lu_gp_mem(lu_gp_mem,
2281                                default_lu_gp);
2282                spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2283
2284                pr_debug("%s: Adding to default ALUA LU Group:"
2285                        " core/alua/lu_gps/default_lu_gp\n",
2286                        dev->transport->name);
2287        }
2288
2289        return 0;
2290}
2291