drivers/target/target_core_alua.c

   1 /*******************************************************************************
   2  * Filename:  target_core_alua.c
   3  *
   4  * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
   5  *
   6  * Copyright (c) 2009-2010 Rising Tide Systems
   7  * Copyright (c) 2009-2010 Linux-iSCSI.org
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  *
  25  ******************************************************************************/
  26
  27 #include <linux/slab.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/configfs.h>
  30 #include <linux/export.h>
  31 #include <scsi/scsi.h>
  32 #include <scsi/scsi_cmnd.h>
  33 #include <asm/unaligned.h>
  34
  35 #include <target/target_core_base.h>
  36 #include <target/target_core_backend.h>
  37 #include <target/target_core_fabric.h>
  38 #include <target/target_core_configfs.h>
  39
  40 #include "target_core_internal.h"
  41 #include "target_core_alua.h"
  42 #include "target_core_ua.h"
  43
  44 static int core_alua_check_transition(int state, int *primary);
  45 static int core_alua_set_tg_pt_secondary_state(
  46                 struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
  47                 struct se_port *port, int explict, int offline);
  48
  49 static u16 alua_lu_gps_counter;
  50 static u32 alua_lu_gps_count;
  51
  52 static DEFINE_SPINLOCK(lu_gps_lock);
  53 static LIST_HEAD(lu_gps_list);
  54
  55 struct t10_alua_lu_gp *default_lu_gp;
  56
  57 /*
  58  * REPORT_TARGET_PORT_GROUPS
  59  *
  60  * See spc4r17 section 6.27
  61  */
  62 int target_emulate_report_target_port_groups(struct se_cmd *cmd)
  63 {
  64         struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
  65         struct se_port *port;
  66         struct t10_alua_tg_pt_gp *tg_pt_gp;
  67         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
  68         unsigned char *buf;
  69         u32 rd_len = 0, off;
  70         int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
  71         /*
  72          * Skip over RESERVED area to first Target port group descriptor
  73          * depending on the PARAMETER DATA FORMAT type..
  74          */
  75         if (ext_hdr != 0)
  76                 off = 8;
  77         else
  78                 off = 4;
  79
  80         if (cmd->data_length < off) {
  81                 pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
  82                         " small for %s header\n", cmd->data_length,
  83                         (ext_hdr) ? "extended" : "normal");
  84                 cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
  85                 return -EINVAL;
  86         }
  87         buf = transport_kmap_data_sg(cmd);
  88
  89         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
  90         list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
  91                         tg_pt_gp_list) {
  92                 /*
  93                  * Check if the Target port group and Target port descriptor list
  94                  * based on tg_pt_gp_members count will fit into the response payload.
  95                  * Otherwise, bump rd_len to let the initiator know we have exceeded
  96                  * the allocation length and the response is truncated.
  97                  */
  98                 if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
  99                      cmd->data_length) {
 100                         rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
 101                         continue;
 102                 }
 103                 /*
 104                  * PREF: Preferred target port bit, determine if this
 105                  * bit should be set for port group.
 106                  */
 107                 if (tg_pt_gp->tg_pt_gp_pref)
 108                         buf[off] = 0x80;
 109                 /*
 110                  * Set the ASYMMETRIC ACCESS State
 111                  */
 112                 buf[off++] |= (atomic_read(
 113                         &tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
 114                 /*
 115                  * Set supported ASYMMETRIC ACCESS State bits
 116                  */
 117                 buf[off] = 0x80; /* T_SUP */
 118                 buf[off] |= 0x40; /* O_SUP */
 119                 buf[off] |= 0x8; /* U_SUP */
 120                 buf[off] |= 0x4; /* S_SUP */
 121                 buf[off] |= 0x2; /* AN_SUP */
 122                 buf[off++] |= 0x1; /* AO_SUP */
 123                 /*
 124                  * TARGET PORT GROUP
 125                  */
 126                 buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
 127                 buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
 128
 129                 off++; /* Skip over Reserved */
 130                 /*
 131                  * STATUS CODE
 132                  */
 133                 buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
 134                 /*
 135                  * Vendor Specific field
 136                  */
 137                 buf[off++] = 0x00;
 138                 /*
 139                  * TARGET PORT COUNT
 140                  */
 141                 buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
 142                 rd_len += 8;
 143
 144                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 145                 list_for_each_entry(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
 146                                 tg_pt_gp_mem_list) {
 147                         port = tg_pt_gp_mem->tg_pt;
 148                         /*
 149                          * Start Target Port descriptor format
 150                          *
 151                          * See spc4r17 section 6.2.7 Table 247
 152                          */
 153                         off += 2; /* Skip over Obsolete */
 154                         /*
 155                          * Set RELATIVE TARGET PORT IDENTIFIER
 156                          */
 157                         buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
 158                         buf[off++] = (port->sep_rtpi & 0xff);
 159                         rd_len += 4;
 160                 }
 161                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 162         }
 163         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 164         /*
 165          * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 166          */
 167         put_unaligned_be32(rd_len, &buf[0]);
 168
 169         /*
 170          * Fill in the Extended header parameter data format if requested
 171          */
 172         if (ext_hdr != 0) {
 173                 buf[4] = 0x10;
 174                 /*
 175                  * Set the implict transition time (in seconds) for the application
 176                  * client to use as a base for it's transition timeout value.
 177                  *
 178                  * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
 179                  * this CDB was received upon to determine this value individually
 180                  * for ALUA target port group.
 181                  */
 182                 port = cmd->se_lun->lun_sep;
 183                 tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 184                 if (tg_pt_gp_mem) {
 185                         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 186                         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
 187                         if (tg_pt_gp)
 188                                 buf[5] = tg_pt_gp->tg_pt_gp_implict_trans_secs;
 189                         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 190                 }
 191         }
 192         transport_kunmap_data_sg(cmd);
 193
 194         target_complete_cmd(cmd, GOOD);
 195         return 0;
 196 }
 197
 198 /*
 199  * SET_TARGET_PORT_GROUPS for explict ALUA operation.
 200  *
 201  * See spc4r17 section 6.35
 202  */
 203 int target_emulate_set_target_port_groups(struct se_cmd *cmd)
 204 {
 205         struct se_device *dev = cmd->se_dev;
 206         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
 207         struct se_port *port, *l_port = cmd->se_lun->lun_sep;
 208         struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
 209         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
 210         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
 211         unsigned char *buf;
 212         unsigned char *ptr;
 213         u32 len = 4; /* Skip over RESERVED area in header */
 214         int alua_access_state, primary = 0, rc;
 215         u16 tg_pt_id, rtpi;
 216
 217         if (!l_port) {
 218                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 219                 return -EINVAL;
 220         }
 221         buf = transport_kmap_data_sg(cmd);
 222
 223         /*
 224          * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
 225          * for the local tg_pt_gp.
 226          */
 227         l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
 228         if (!l_tg_pt_gp_mem) {
 229                 pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
 230                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 231                 rc = -EINVAL;
 232                 goto out;
 233         }
 234         spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 235         l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
 236         if (!l_tg_pt_gp) {
 237                 spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 238                 pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
 239                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 240                 rc = -EINVAL;
 241                 goto out;
 242         }
 243         rc = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
 244         spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
 245
 246         if (!rc) {
 247                 pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
 248                                 " while TPGS_EXPLICT_ALUA is disabled\n");
 249                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 250                 rc = -EINVAL;
 251                 goto out;
 252         }
 253
 254         ptr = &buf[4]; /* Skip over RESERVED area in header */
 255
 256         while (len < cmd->data_length) {
 257                 alua_access_state = (ptr[0] & 0x0f);
 258                 /*
 259                  * Check the received ALUA access state, and determine if
 260                  * the state is a primary or secondary target port asymmetric
 261                  * access state.
 262                  */
 263                 rc = core_alua_check_transition(alua_access_state, &primary);
 264                 if (rc != 0) {
 265                         /*
 266                          * If the SET TARGET PORT GROUPS attempts to establish
 267                          * an invalid combination of target port asymmetric
 268                          * access states or attempts to establish an
 269                          * unsupported target port asymmetric access state,
 270                          * then the command shall be terminated with CHECK
 271                          * CONDITION status, with the sense key set to ILLEGAL
 272                          * REQUEST, and the additional sense code set to INVALID
 273                          * FIELD IN PARAMETER LIST.
 274                          */
 275                         cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 276                         rc = -EINVAL;
 277                         goto out;
 278                 }
 279                 rc = -1;
 280                 /*
 281                  * If the ASYMMETRIC ACCESS STATE field (see table 267)
 282                  * specifies a primary target port asymmetric access state,
 283                  * then the TARGET PORT GROUP OR TARGET PORT field specifies
 284                  * a primary target port group for which the primary target
 285                  * port asymmetric access state shall be changed. If the
 286                  * ASYMMETRIC ACCESS STATE field specifies a secondary target
 287                  * port asymmetric access state, then the TARGET PORT GROUP OR
 288                  * TARGET PORT field specifies the relative target port
 289                  * identifier (see 3.1.120) of the target port for which the
 290                  * secondary target port asymmetric access state shall be
 291                  * changed.
 292                  */
 293                 if (primary) {
 294                         tg_pt_id = get_unaligned_be16(ptr + 2);
 295                         /*
 296                          * Locate the matching target port group ID from
 297                          * the global tg_pt_gp list
 298                          */
 299                         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 300                         list_for_each_entry(tg_pt_gp,
 301                                         &su_dev->t10_alua.tg_pt_gps_list,
 302                                         tg_pt_gp_list) {
 303                                 if (!tg_pt_gp->tg_pt_gp_valid_id)
 304                                         continue;
 305
 306                                 if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
 307                                         continue;
 308
 309                                 atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 310                                 smp_mb__after_atomic_inc();
 311                                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 312
 313                                 rc = core_alua_do_port_transition(tg_pt_gp,
 314                                                 dev, l_port, nacl,
 315                                                 alua_access_state, 1);
 316
 317                                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 318                                 atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
 319                                 smp_mb__after_atomic_dec();
 320                                 break;
 321                         }
 322                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 323                         /*
 324                          * If not matching target port group ID can be located
 325                          * throw an exception with ASCQ: INVALID_PARAMETER_LIST
 326                          */
 327                         if (rc != 0) {
 328                                 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 329                                 rc = -EINVAL;
 330                                 goto out;
 331                         }
 332                 } else {
 333                         /*
 334                          * Extact the RELATIVE TARGET PORT IDENTIFIER to identify
 335                          * the Target Port in question for the the incoming
 336                          * SET_TARGET_PORT_GROUPS op.
 337                          */
 338                         rtpi = get_unaligned_be16(ptr + 2);
 339                         /*
 340                          * Locate the matching relative target port identifer
 341                          * for the struct se_device storage object.
 342                          */
 343                         spin_lock(&dev->se_port_lock);
 344                         list_for_each_entry(port, &dev->dev_sep_list,
 345                                                         sep_list) {
 346                                 if (port->sep_rtpi != rtpi)
 347                                         continue;
 348
 349                                 tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 350                                 spin_unlock(&dev->se_port_lock);
 351
 352                                 rc = core_alua_set_tg_pt_secondary_state(
 353                                                 tg_pt_gp_mem, port, 1, 1);
 354
 355                                 spin_lock(&dev->se_port_lock);
 356                                 break;
 357                         }
 358                         spin_unlock(&dev->se_port_lock);
 359                         /*
 360                          * If not matching relative target port identifier can
 361                          * be located, throw an exception with ASCQ:
 362                          * INVALID_PARAMETER_LIST
 363                          */
 364                         if (rc != 0) {
 365                                 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
 366                                 rc = -EINVAL;
 367                                 goto out;
 368                         }
 369                 }
 370
 371                 ptr += 4;
 372                 len += 4;
 373         }
 374
 375 out:
 376         transport_kunmap_data_sg(cmd);
 377         if (!rc)
 378                 target_complete_cmd(cmd, GOOD);
 379         return rc;
 380 }
 381
 382 static inline int core_alua_state_nonoptimized(
 383         struct se_cmd *cmd,
 384         unsigned char *cdb,
 385         int nonop_delay_msecs,
 386         u8 *alua_ascq)
 387 {
 388         /*
 389          * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
 390          * later to determine if processing of this cmd needs to be
 391          * temporarily delayed for the Active/NonOptimized primary access state.
 392          */
 393         cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
 394         cmd->alua_nonop_delay = nonop_delay_msecs;
 395         return 0;
 396 }
 397
 398 static inline int core_alua_state_standby(
 399         struct se_cmd *cmd,
 400         unsigned char *cdb,
 401         u8 *alua_ascq)
 402 {
 403         /*
 404          * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
 405          * spc4r17 section 5.9.2.4.4
 406          */
 407         switch (cdb[0]) {
 408         case INQUIRY:
 409         case LOG_SELECT:
 410         case LOG_SENSE:
 411         case MODE_SELECT:
 412         case MODE_SENSE:
 413         case REPORT_LUNS:
 414         case RECEIVE_DIAGNOSTIC:
 415         case SEND_DIAGNOSTIC:
 416         case MAINTENANCE_IN:
 417                 switch (cdb[1] & 0x1f) {
 418                 case MI_REPORT_TARGET_PGS:
 419                         return 0;
 420                 default:
 421                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 422                         return 1;
 423                 }
 424         case MAINTENANCE_OUT:
 425                 switch (cdb[1]) {
 426                 case MO_SET_TARGET_PGS:
 427                         return 0;
 428                 default:
 429                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 430                         return 1;
 431                 }
 432         case REQUEST_SENSE:
 433         case PERSISTENT_RESERVE_IN:
 434         case PERSISTENT_RESERVE_OUT:
 435         case READ_BUFFER:
 436         case WRITE_BUFFER:
 437                 return 0;
 438         default:
 439                 *alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
 440                 return 1;
 441         }
 442
 443         return 0;
 444 }
 445
 446 static inline int core_alua_state_unavailable(
 447         struct se_cmd *cmd,
 448         unsigned char *cdb,
 449         u8 *alua_ascq)
 450 {
 451         /*
 452          * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
 453          * spc4r17 section 5.9.2.4.5
 454          */
 455         switch (cdb[0]) {
 456         case INQUIRY:
 457         case REPORT_LUNS:
 458         case MAINTENANCE_IN:
 459                 switch (cdb[1] & 0x1f) {
 460                 case MI_REPORT_TARGET_PGS:
 461                         return 0;
 462                 default:
 463                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 464                         return 1;
 465                 }
 466         case MAINTENANCE_OUT:
 467                 switch (cdb[1]) {
 468                 case MO_SET_TARGET_PGS:
 469                         return 0;
 470                 default:
 471                         *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 472                         return 1;
 473                 }
 474         case REQUEST_SENSE:
 475         case READ_BUFFER:
 476         case WRITE_BUFFER:
 477                 return 0;
 478         default:
 479                 *alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
 480                 return 1;
 481         }
 482
 483         return 0;
 484 }
 485
 486 static inline int core_alua_state_transition(
 487         struct se_cmd *cmd,
 488         unsigned char *cdb,
 489         u8 *alua_ascq)
 490 {
 491         /*
 492          * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
 493          * spc4r17 section 5.9.2.5
 494          */
 495         switch (cdb[0]) {
 496         case INQUIRY:
 497         case REPORT_LUNS:
 498         case MAINTENANCE_IN:
 499                 switch (cdb[1] & 0x1f) {
 500                 case MI_REPORT_TARGET_PGS:
 501                         return 0;
 502                 default:
 503                         *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 504                         return 1;
 505                 }
 506         case REQUEST_SENSE:
 507         case READ_BUFFER:
 508         case WRITE_BUFFER:
 509                 return 0;
 510         default:
 511                 *alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
 512                 return 1;
 513         }
 514
 515         return 0;
 516 }
 517
 518 /*
 519  * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
 520  * in transport_cmd_sequencer().  This function is assigned to
 521  * struct t10_alua *->state_check() in core_setup_alua()
 522  */
 523 static int core_alua_state_check_nop(
 524         struct se_cmd *cmd,
 525         unsigned char *cdb,
 526         u8 *alua_ascq)
 527 {
 528         return 0;
 529 }
 530
 531 /*
 532  * Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
 533  * This function is assigned to struct t10_alua *->state_check() in
 534  * core_setup_alua()
 535  *
 536  * Also, this function can return three different return codes to
 537  * signal transport_generic_cmd_sequencer()
 538  *
 539  * return 1: Is used to signal LUN not accecsable, and check condition/not ready
 540  * return 0: Used to signal success
 541  * reutrn -1: Used to signal failure, and invalid cdb field
 542  */
 543 static int core_alua_state_check(
 544         struct se_cmd *cmd,
 545         unsigned char *cdb,
 546         u8 *alua_ascq)
 547 {
 548         struct se_lun *lun = cmd->se_lun;
 549         struct se_port *port = lun->lun_sep;
 550         struct t10_alua_tg_pt_gp *tg_pt_gp;
 551         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
 552         int out_alua_state, nonop_delay_msecs;
 553
 554         if (!port)
 555                 return 0;
 556         /*
 557          * First, check for a struct se_port specific secondary ALUA target port
 558          * access state: OFFLINE
 559          */
 560         if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
 561                 *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 562                 pr_debug("ALUA: Got secondary offline status for local"
 563                                 " target port\n");
 564                 *alua_ascq = ASCQ_04H_ALUA_OFFLINE;
 565                 return 1;
 566         }
 567          /*
 568          * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
 569          * ALUA target port group, to obtain current ALUA access state.
 570          * Otherwise look for the underlying struct se_device association with
 571          * a ALUA logical unit group.
 572          */
 573         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
 574         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 575         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
 576         out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 577         nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
 578         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
 579         /*
 580          * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a separate conditional
 581          * statement so the compiler knows explicitly to check this case first.
 582          * For the Optimized ALUA access state case, we want to process the
 583          * incoming fabric cmd ASAP..
 584          */
 585         if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
 586                 return 0;
 587
 588         switch (out_alua_state) {
 589         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 590                 return core_alua_state_nonoptimized(cmd, cdb,
 591                                         nonop_delay_msecs, alua_ascq);
 592         case ALUA_ACCESS_STATE_STANDBY:
 593                 return core_alua_state_standby(cmd, cdb, alua_ascq);
 594         case ALUA_ACCESS_STATE_UNAVAILABLE:
 595                 return core_alua_state_unavailable(cmd, cdb, alua_ascq);
 596         case ALUA_ACCESS_STATE_TRANSITION:
 597                 return core_alua_state_transition(cmd, cdb, alua_ascq);
 598         /*
 599          * OFFLINE is a secondary ALUA target port group access state, that is
 600          * handled above with struct se_port->sep_tg_pt_secondary_offline=1
 601          */
 602         case ALUA_ACCESS_STATE_OFFLINE:
 603         default:
 604                 pr_err("Unknown ALUA access state: 0x%02x\n",
 605                                 out_alua_state);
 606                 return -EINVAL;
 607         }
 608
 609         return 0;
 610 }
 611
 612 /*
 613  * Check implict and explict ALUA state change request.
 614  */
 615 static int core_alua_check_transition(int state, int *primary)
 616 {
 617         switch (state) {
 618         case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 619         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 620         case ALUA_ACCESS_STATE_STANDBY:
 621         case ALUA_ACCESS_STATE_UNAVAILABLE:
 622                 /*
 623                  * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
 624                  * defined as primary target port asymmetric access states.
 625                  */
 626                 *primary = 1;
 627                 break;
 628         case ALUA_ACCESS_STATE_OFFLINE:
 629                 /*
 630                  * OFFLINE state is defined as a secondary target port
 631                  * asymmetric access state.
 632                  */
 633                 *primary = 0;
 634                 break;
 635         default:
 636                 pr_err("Unknown ALUA access state: 0x%02x\n", state);
 637                 return -EINVAL;
 638         }
 639
 640         return 0;
 641 }
 642
 643 static char *core_alua_dump_state(int state)
 644 {
 645         switch (state) {
 646         case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
 647                 return "Active/Optimized";
 648         case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 649                 return "Active/NonOptimized";
 650         case ALUA_ACCESS_STATE_STANDBY:
 651                 return "Standby";
 652         case ALUA_ACCESS_STATE_UNAVAILABLE:
 653                 return "Unavailable";
 654         case ALUA_ACCESS_STATE_OFFLINE:
 655                 return "Offline";
 656         default:
 657                 return "Unknown";
 658         }
 659
 660         return NULL;
 661 }
 662
 663 char *core_alua_dump_status(int status)
 664 {
 665         switch (status) {
 666         case ALUA_STATUS_NONE:
 667                 return "None";
 668         case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
 669                 return "Altered by Explict STPG";
 670         case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
 671                 return "Altered by Implict ALUA";
 672         default:
 673                 return "Unknown";
 674         }
 675
 676         return NULL;
 677 }
 678
 679 /*
 680  * Used by fabric modules to determine when we need to delay processing
 681  * for the Active/NonOptimized paths..
 682  */
 683 int core_alua_check_nonop_delay(
 684         struct se_cmd *cmd)
 685 {
 686         if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
 687                 return 0;
 688         if (in_interrupt())
 689                 return 0;
 690         /*
 691          * The ALUA Active/NonOptimized access state delay can be disabled
 692          * in via configfs with a value of zero
 693          */
 694         if (!cmd->alua_nonop_delay)
 695                 return 0;
 696         /*
 697          * struct se_cmd->alua_nonop_delay gets set by a target port group
 698          * defined interval in core_alua_state_nonoptimized()
 699          */
 700         msleep_interruptible(cmd->alua_nonop_delay);
 701         return 0;
 702 }
 703 EXPORT_SYMBOL(core_alua_check_nonop_delay);
 704
 705 /*
 706  * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
 707  *
 708  */
 709 static int core_alua_write_tpg_metadata(
 710         const char *path,
 711         unsigned char *md_buf,
 712         u32 md_buf_len)
 713 {
 714         mm_segment_t old_fs;
 715         struct file *file;
 716         struct iovec iov[1];
 717         int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
 718
 719         memset(iov, 0, sizeof(struct iovec));
 720
 721         file = filp_open(path, flags, 0600);
 722         if (IS_ERR(file) || !file || !file->f_dentry) {
 723                 pr_err("filp_open(%s) for ALUA metadata failed\n",
 724                         path);
 725                 return -ENODEV;
 726         }
 727
 728         iov[0].iov_base = &md_buf[0];
 729         iov[0].iov_len = md_buf_len;
 730
 731         old_fs = get_fs();
 732         set_fs(get_ds());
 733         ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
 734         set_fs(old_fs);
 735
 736         if (ret < 0) {
 737                 pr_err("Error writing ALUA metadata file: %s\n", path);
 738                 filp_close(file, NULL);
 739                 return -EIO;
 740         }
 741         filp_close(file, NULL);
 742
 743         return 0;
 744 }
 745
 746 /*
 747  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
 748  */
 749 static int core_alua_update_tpg_primary_metadata(
 750         struct t10_alua_tg_pt_gp *tg_pt_gp,
 751         int primary_state,
 752         unsigned char *md_buf)
 753 {
 754         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
 755         struct t10_wwn *wwn = &su_dev->t10_wwn;
 756         char path[ALUA_METADATA_PATH_LEN];
 757         int len;
 758
 759         memset(path, 0, ALUA_METADATA_PATH_LEN);
 760
 761         len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
 762                         "tg_pt_gp_id=%hu\n"
 763                         "alua_access_state=0x%02x\n"
 764                         "alua_access_status=0x%02x\n",
 765                         tg_pt_gp->tg_pt_gp_id, primary_state,
 766                         tg_pt_gp->tg_pt_gp_alua_access_status);
 767
 768         snprintf(path, ALUA_METADATA_PATH_LEN,
 769                 "/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
 770                 config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 771
 772         return core_alua_write_tpg_metadata(path, md_buf, len);
 773 }
 774
 775 static int core_alua_do_transition_tg_pt(
 776         struct t10_alua_tg_pt_gp *tg_pt_gp,
 777         struct se_port *l_port,
 778         struct se_node_acl *nacl,
 779         unsigned char *md_buf,
 780         int new_state,
 781         int explict)
 782 {
 783         struct se_dev_entry *se_deve;
 784         struct se_lun_acl *lacl;
 785         struct se_port *port;
 786         struct t10_alua_tg_pt_gp_member *mem;
 787         int old_state = 0;
 788         /*
 789          * Save the old primary ALUA access state, and set the current state
 790          * to ALUA_ACCESS_STATE_TRANSITION.
 791          */
 792         old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
 793         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
 794                         ALUA_ACCESS_STATE_TRANSITION);
 795         tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
 796                                 ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
 797                                 ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
 798         /*
 799          * Check for the optional ALUA primary state transition delay
 800          */
 801         if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
 802                 msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
 803
 804         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 805         list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
 806                                 tg_pt_gp_mem_list) {
 807                 port = mem->tg_pt;
 808                 /*
 809                  * After an implicit target port asymmetric access state
 810                  * change, a device server shall establish a unit attention
 811                  * condition for the initiator port associated with every I_T
 812                  * nexus with the additional sense code set to ASYMMETRIC
 813                  * ACCESS STATE CHAGED.
 814                  *
 815                  * After an explicit target port asymmetric access state
 816                  * change, a device server shall establish a unit attention
 817                  * condition with the additional sense code set to ASYMMETRIC
 818                  * ACCESS STATE CHANGED for the initiator port associated with
 819                  * every I_T nexus other than the I_T nexus on which the SET
 820                  * TARGET PORT GROUPS command
 821                  */
 822                 atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
 823                 smp_mb__after_atomic_inc();
 824                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 825
 826                 spin_lock_bh(&port->sep_alua_lock);
 827                 list_for_each_entry(se_deve, &port->sep_alua_list,
 828                                         alua_port_list) {
 829                         lacl = se_deve->se_lun_acl;
 830                         /*
 831                          * se_deve->se_lun_acl pointer may be NULL for a
 832                          * entry created without explict Node+MappedLUN ACLs
 833                          */
 834                         if (!lacl)
 835                                 continue;
 836
 837                         if (explict &&
 838                            (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
 839                            (l_port != NULL) && (l_port == port))
 840                                 continue;
 841
 842                         core_scsi3_ua_allocate(lacl->se_lun_nacl,
 843                                 se_deve->mapped_lun, 0x2A,
 844                                 ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
 845                 }
 846                 spin_unlock_bh(&port->sep_alua_lock);
 847
 848                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 849                 atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
 850                 smp_mb__after_atomic_dec();
 851         }
 852         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 853         /*
 854          * Update the ALUA metadata buf that has been allocated in
 855          * core_alua_do_port_transition(), this metadata will be written
 856          * to struct file.
 857          *
 858          * Note that there is the case where we do not want to update the
 859          * metadata when the saved metadata is being parsed in userspace
 860          * when setting the existing port access state and access status.
 861          *
 862          * Also note that the failure to write out the ALUA metadata to
 863          * struct file does NOT affect the actual ALUA transition.
 864          */
 865         if (tg_pt_gp->tg_pt_gp_write_metadata) {
 866                 mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
 867                 core_alua_update_tpg_primary_metadata(tg_pt_gp,
 868                                         new_state, md_buf);
 869                 mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
 870         }
 871         /*
 872          * Set the current primary ALUA access state to the requested new state
 873          */
 874         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
 875
 876         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
 877                 " from primary access state %s to %s\n", (explict) ? "explict" :
 878                 "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
 879                 tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
 880                 core_alua_dump_state(new_state));
 881
 882         return 0;
 883 }
 884
 885 int core_alua_do_port_transition(
 886         struct t10_alua_tg_pt_gp *l_tg_pt_gp,
 887         struct se_device *l_dev,
 888         struct se_port *l_port,
 889         struct se_node_acl *l_nacl,
 890         int new_state,
 891         int explict)
 892 {
 893         struct se_device *dev;
 894         struct se_port *port;
 895         struct se_subsystem_dev *su_dev;
 896         struct se_node_acl *nacl;
 897         struct t10_alua_lu_gp *lu_gp;
 898         struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
 899         struct t10_alua_tg_pt_gp *tg_pt_gp;
 900         unsigned char *md_buf;
 901         int primary;
 902
 903         if (core_alua_check_transition(new_state, &primary) != 0)
 904                 return -EINVAL;
 905
 906         md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
 907         if (!md_buf) {
 908                 pr_err("Unable to allocate buf for ALUA metadata\n");
 909                 return -ENOMEM;
 910         }
 911
 912         local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
 913         spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
 914         lu_gp = local_lu_gp_mem->lu_gp;
 915         atomic_inc(&lu_gp->lu_gp_ref_cnt);
 916         smp_mb__after_atomic_inc();
 917         spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
 918         /*
 919          * For storage objects that are members of the 'default_lu_gp',
 920          * we only do transition on the passed *l_tp_pt_gp, and not
 921          * on all of the matching target port groups IDs in default_lu_gp.
 922          */
 923         if (!lu_gp->lu_gp_id) {
 924                 /*
 925                  * core_alua_do_transition_tg_pt() will always return
 926                  * success.
 927                  */
 928                 core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
 929                                         md_buf, new_state, explict);
 930                 atomic_dec(&lu_gp->lu_gp_ref_cnt);
 931                 smp_mb__after_atomic_dec();
 932                 kfree(md_buf);
 933                 return 0;
 934         }
 935         /*
 936          * For all other LU groups aside from 'default_lu_gp', walk all of
 937          * the associated storage objects looking for a matching target port
 938          * group ID from the local target port group.
 939          */
 940         spin_lock(&lu_gp->lu_gp_lock);
 941         list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
 942                                 lu_gp_mem_list) {
 943
 944                 dev = lu_gp_mem->lu_gp_mem_dev;
 945                 su_dev = dev->se_sub_dev;
 946                 atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
 947                 smp_mb__after_atomic_inc();
 948                 spin_unlock(&lu_gp->lu_gp_lock);
 949
 950                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 951                 list_for_each_entry(tg_pt_gp,
 952                                 &su_dev->t10_alua.tg_pt_gps_list,
 953                                 tg_pt_gp_list) {
 954
 955                         if (!tg_pt_gp->tg_pt_gp_valid_id)
 956                                 continue;
 957                         /*
 958                          * If the target behavior port asymmetric access state
 959                          * is changed for any target port group accessiable via
 960                          * a logical unit within a LU group, the target port
 961                          * behavior group asymmetric access states for the same
 962                          * target port group accessible via other logical units
 963                          * in that LU group will also change.
 964                          */
 965                         if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
 966                                 continue;
 967
 968                         if (l_tg_pt_gp == tg_pt_gp) {
 969                                 port = l_port;
 970                                 nacl = l_nacl;
 971                         } else {
 972                                 port = NULL;
 973                                 nacl = NULL;
 974                         }
 975                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 976                         smp_mb__after_atomic_inc();
 977                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 978                         /*
 979                          * core_alua_do_transition_tg_pt() will always return
 980                          * success.
 981                          */
 982                         core_alua_do_transition_tg_pt(tg_pt_gp, port,
 983                                         nacl, md_buf, new_state, explict);
 984
 985                         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
 986                         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
 987                         smp_mb__after_atomic_dec();
 988                 }
 989                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
 990
 991                 spin_lock(&lu_gp->lu_gp_lock);
 992                 atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
 993                 smp_mb__after_atomic_dec();
 994         }
 995         spin_unlock(&lu_gp->lu_gp_lock);
 996
 997         pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
 998                 " Group IDs: %hu %s transition to primary state: %s\n",
 999                 config_item_name(&lu_gp->lu_gp_group.cg_item),
1000                 l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
1001                 core_alua_dump_state(new_state));
1002
1003         atomic_dec(&lu_gp->lu_gp_ref_cnt);
1004         smp_mb__after_atomic_dec();
1005         kfree(md_buf);
1006         return 0;
1007 }
1008
1009 /*
1010  * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
1011  */
1012 static int core_alua_update_tpg_secondary_metadata(
1013         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1014         struct se_port *port,
1015         unsigned char *md_buf,
1016         u32 md_buf_len)
1017 {
1018         struct se_portal_group *se_tpg = port->sep_tpg;
1019         char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
1020         int len;
1021
1022         memset(path, 0, ALUA_METADATA_PATH_LEN);
1023         memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1024
1025         len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1026                         se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1027
1028         if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1029                 snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1030                                 se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1031
1032         len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1033                         "alua_tg_pt_status=0x%02x\n",
1034                         atomic_read(&port->sep_tg_pt_secondary_offline),
1035                         port->sep_tg_pt_secondary_stat);
1036
1037         snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1038                         se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1039                         port->sep_lun->unpacked_lun);
1040
1041         return core_alua_write_tpg_metadata(path, md_buf, len);
1042 }
1043
1044 static int core_alua_set_tg_pt_secondary_state(
1045         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1046         struct se_port *port,
1047         int explict,
1048         int offline)
1049 {
1050         struct t10_alua_tg_pt_gp *tg_pt_gp;
1051         unsigned char *md_buf;
1052         u32 md_buf_len;
1053         int trans_delay_msecs;
1054
1055         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1056         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1057         if (!tg_pt_gp) {
1058                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1059                 pr_err("Unable to complete secondary state"
1060                                 " transition\n");
1061                 return -EINVAL;
1062         }
1063         trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1064         /*
1065          * Set the secondary ALUA target port access state to OFFLINE
1066          * or release the previously secondary state for struct se_port
1067          */
1068         if (offline)
1069                 atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1070         else
1071                 atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1072
1073         md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1074         port->sep_tg_pt_secondary_stat = (explict) ?
1075                         ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
1076                         ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
1077
1078         pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1079                 " to secondary access state: %s\n", (explict) ? "explict" :
1080                 "implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1081                 tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1082
1083         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1084         /*
1085          * Do the optional transition delay after we set the secondary
1086          * ALUA access state.
1087          */
1088         if (trans_delay_msecs != 0)
1089                 msleep_interruptible(trans_delay_msecs);
1090         /*
1091          * See if we need to update the ALUA fabric port metadata for
1092          * secondary state and status
1093          */
1094         if (port->sep_tg_pt_secondary_write_md) {
1095                 md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1096                 if (!md_buf) {
1097                         pr_err("Unable to allocate md_buf for"
1098                                 " secondary ALUA access metadata\n");
1099                         return -ENOMEM;
1100                 }
1101                 mutex_lock(&port->sep_tg_pt_md_mutex);
1102                 core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1103                                 md_buf, md_buf_len);
1104                 mutex_unlock(&port->sep_tg_pt_md_mutex);
1105
1106                 kfree(md_buf);
1107         }
1108
1109         return 0;
1110 }
1111
1112 struct t10_alua_lu_gp *
1113 core_alua_allocate_lu_gp(const char *name, int def_group)
1114 {
1115         struct t10_alua_lu_gp *lu_gp;
1116
1117         lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1118         if (!lu_gp) {
1119                 pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1120                 return ERR_PTR(-ENOMEM);
1121         }
1122         INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1123         INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1124         spin_lock_init(&lu_gp->lu_gp_lock);
1125         atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1126
1127         if (def_group) {
1128                 lu_gp->lu_gp_id = alua_lu_gps_counter++;
1129                 lu_gp->lu_gp_valid_id = 1;
1130                 alua_lu_gps_count++;
1131         }
1132
1133         return lu_gp;
1134 }
1135
1136 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1137 {
1138         struct t10_alua_lu_gp *lu_gp_tmp;
1139         u16 lu_gp_id_tmp;
1140         /*
1141          * The lu_gp->lu_gp_id may only be set once..
1142          */
1143         if (lu_gp->lu_gp_valid_id) {
1144                 pr_warn("ALUA LU Group already has a valid ID,"
1145                         " ignoring request\n");
1146                 return -EINVAL;
1147         }
1148
1149         spin_lock(&lu_gps_lock);
1150         if (alua_lu_gps_count == 0x0000ffff) {
1151                 pr_err("Maximum ALUA alua_lu_gps_count:"
1152                                 " 0x0000ffff reached\n");
1153                 spin_unlock(&lu_gps_lock);
1154                 kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1155                 return -ENOSPC;
1156         }
1157 again:
1158         lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1159                                 alua_lu_gps_counter++;
1160
1161         list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1162                 if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1163                         if (!lu_gp_id)
1164                                 goto again;
1165
1166                         pr_warn("ALUA Logical Unit Group ID: %hu"
1167                                 " already exists, ignoring request\n",
1168                                 lu_gp_id);
1169                         spin_unlock(&lu_gps_lock);
1170                         return -EINVAL;
1171                 }
1172         }
1173
1174         lu_gp->lu_gp_id = lu_gp_id_tmp;
1175         lu_gp->lu_gp_valid_id = 1;
1176         list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1177         alua_lu_gps_count++;
1178         spin_unlock(&lu_gps_lock);
1179
1180         return 0;
1181 }
1182
1183 static struct t10_alua_lu_gp_member *
1184 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1185 {
1186         struct t10_alua_lu_gp_member *lu_gp_mem;
1187
1188         lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1189         if (!lu_gp_mem) {
1190                 pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1191                 return ERR_PTR(-ENOMEM);
1192         }
1193         INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1194         spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1195         atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1196
1197         lu_gp_mem->lu_gp_mem_dev = dev;
1198         dev->dev_alua_lu_gp_mem = lu_gp_mem;
1199
1200         return lu_gp_mem;
1201 }
1202
1203 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1204 {
1205         struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1206         /*
1207          * Once we have reached this point, config_item_put() has
1208          * already been called from target_core_alua_drop_lu_gp().
1209          *
1210          * Here, we remove the *lu_gp from the global list so that
1211          * no associations can be made while we are releasing
1212          * struct t10_alua_lu_gp.
1213          */
1214         spin_lock(&lu_gps_lock);
1215         list_del(&lu_gp->lu_gp_node);
1216         alua_lu_gps_count--;
1217         spin_unlock(&lu_gps_lock);
1218         /*
1219          * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1220          * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1221          * released with core_alua_put_lu_gp_from_name()
1222          */
1223         while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1224                 cpu_relax();
1225         /*
1226          * Release reference to struct t10_alua_lu_gp * from all associated
1227          * struct se_device.
1228          */
1229         spin_lock(&lu_gp->lu_gp_lock);
1230         list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1231                                 &lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1232                 if (lu_gp_mem->lu_gp_assoc) {
1233                         list_del(&lu_gp_mem->lu_gp_mem_list);
1234                         lu_gp->lu_gp_members--;
1235                         lu_gp_mem->lu_gp_assoc = 0;
1236                 }
1237                 spin_unlock(&lu_gp->lu_gp_lock);
1238                 /*
1239                  *
1240                  * lu_gp_mem is associated with a single
1241                  * struct se_device->dev_alua_lu_gp_mem, and is released when
1242                  * struct se_device is released via core_alua_free_lu_gp_mem().
1243                  *
1244                  * If the passed lu_gp does NOT match the default_lu_gp, assume
1245                  * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1246                  */
1247                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1248                 if (lu_gp != default_lu_gp)
1249                         __core_alua_attach_lu_gp_mem(lu_gp_mem,
1250                                         default_lu_gp);
1251                 else
1252                         lu_gp_mem->lu_gp = NULL;
1253                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1254
1255                 spin_lock(&lu_gp->lu_gp_lock);
1256         }
1257         spin_unlock(&lu_gp->lu_gp_lock);
1258
1259         kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1260 }
1261
1262 void core_alua_free_lu_gp_mem(struct se_device *dev)
1263 {
1264         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1265         struct t10_alua *alua = &su_dev->t10_alua;
1266         struct t10_alua_lu_gp *lu_gp;
1267         struct t10_alua_lu_gp_member *lu_gp_mem;
1268
1269         if (alua->alua_type != SPC3_ALUA_EMULATED)
1270                 return;
1271
1272         lu_gp_mem = dev->dev_alua_lu_gp_mem;
1273         if (!lu_gp_mem)
1274                 return;
1275
1276         while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1277                 cpu_relax();
1278
1279         spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1280         lu_gp = lu_gp_mem->lu_gp;
1281         if (lu_gp) {
1282                 spin_lock(&lu_gp->lu_gp_lock);
1283                 if (lu_gp_mem->lu_gp_assoc) {
1284                         list_del(&lu_gp_mem->lu_gp_mem_list);
1285                         lu_gp->lu_gp_members--;
1286                         lu_gp_mem->lu_gp_assoc = 0;
1287                 }
1288                 spin_unlock(&lu_gp->lu_gp_lock);
1289                 lu_gp_mem->lu_gp = NULL;
1290         }
1291         spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1292
1293         kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1294 }
1295
1296 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1297 {
1298         struct t10_alua_lu_gp *lu_gp;
1299         struct config_item *ci;
1300
1301         spin_lock(&lu_gps_lock);
1302         list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1303                 if (!lu_gp->lu_gp_valid_id)
1304                         continue;
1305                 ci = &lu_gp->lu_gp_group.cg_item;
1306                 if (!strcmp(config_item_name(ci), name)) {
1307                         atomic_inc(&lu_gp->lu_gp_ref_cnt);
1308                         spin_unlock(&lu_gps_lock);
1309                         return lu_gp;
1310                 }
1311         }
1312         spin_unlock(&lu_gps_lock);
1313
1314         return NULL;
1315 }
1316
1317 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1318 {
1319         spin_lock(&lu_gps_lock);
1320         atomic_dec(&lu_gp->lu_gp_ref_cnt);
1321         spin_unlock(&lu_gps_lock);
1322 }
1323
1324 /*
1325  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1326  */
1327 void __core_alua_attach_lu_gp_mem(
1328         struct t10_alua_lu_gp_member *lu_gp_mem,
1329         struct t10_alua_lu_gp *lu_gp)
1330 {
1331         spin_lock(&lu_gp->lu_gp_lock);
1332         lu_gp_mem->lu_gp = lu_gp;
1333         lu_gp_mem->lu_gp_assoc = 1;
1334         list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1335         lu_gp->lu_gp_members++;
1336         spin_unlock(&lu_gp->lu_gp_lock);
1337 }
1338
1339 /*
1340  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1341  */
1342 void __core_alua_drop_lu_gp_mem(
1343         struct t10_alua_lu_gp_member *lu_gp_mem,
1344         struct t10_alua_lu_gp *lu_gp)
1345 {
1346         spin_lock(&lu_gp->lu_gp_lock);
1347         list_del(&lu_gp_mem->lu_gp_mem_list);
1348         lu_gp_mem->lu_gp = NULL;
1349         lu_gp_mem->lu_gp_assoc = 0;
1350         lu_gp->lu_gp_members--;
1351         spin_unlock(&lu_gp->lu_gp_lock);
1352 }
1353
1354 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
1355         struct se_subsystem_dev *su_dev,
1356         const char *name,
1357         int def_group)
1358 {
1359         struct t10_alua_tg_pt_gp *tg_pt_gp;
1360
1361         tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1362         if (!tg_pt_gp) {
1363                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1364                 return NULL;
1365         }
1366         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1367         INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1368         mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1369         spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1370         atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1371         tg_pt_gp->tg_pt_gp_su_dev = su_dev;
1372         tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1373         atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1374                 ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1375         /*
1376          * Enable both explict and implict ALUA support by default
1377          */
1378         tg_pt_gp->tg_pt_gp_alua_access_type =
1379                         TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1380         /*
1381          * Set the default Active/NonOptimized Delay in milliseconds
1382          */
1383         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1384         tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1385         tg_pt_gp->tg_pt_gp_implict_trans_secs = ALUA_DEFAULT_IMPLICT_TRANS_SECS;
1386
1387         if (def_group) {
1388                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1389                 tg_pt_gp->tg_pt_gp_id =
1390                                 su_dev->t10_alua.alua_tg_pt_gps_counter++;
1391                 tg_pt_gp->tg_pt_gp_valid_id = 1;
1392                 su_dev->t10_alua.alua_tg_pt_gps_count++;
1393                 list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1394                               &su_dev->t10_alua.tg_pt_gps_list);
1395                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1396         }
1397
1398         return tg_pt_gp;
1399 }
1400
1401 int core_alua_set_tg_pt_gp_id(
1402         struct t10_alua_tg_pt_gp *tg_pt_gp,
1403         u16 tg_pt_gp_id)
1404 {
1405         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1406         struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1407         u16 tg_pt_gp_id_tmp;
1408         /*
1409          * The tg_pt_gp->tg_pt_gp_id may only be set once..
1410          */
1411         if (tg_pt_gp->tg_pt_gp_valid_id) {
1412                 pr_warn("ALUA TG PT Group already has a valid ID,"
1413                         " ignoring request\n");
1414                 return -EINVAL;
1415         }
1416
1417         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1418         if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1419                 pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1420                         " 0x0000ffff reached\n");
1421                 spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1422                 kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1423                 return -ENOSPC;
1424         }
1425 again:
1426         tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1427                         su_dev->t10_alua.alua_tg_pt_gps_counter++;
1428
1429         list_for_each_entry(tg_pt_gp_tmp, &su_dev->t10_alua.tg_pt_gps_list,
1430                         tg_pt_gp_list) {
1431                 if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1432                         if (!tg_pt_gp_id)
1433                                 goto again;
1434
1435                         pr_err("ALUA Target Port Group ID: %hu already"
1436                                 " exists, ignoring request\n", tg_pt_gp_id);
1437                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1438                         return -EINVAL;
1439                 }
1440         }
1441
1442         tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1443         tg_pt_gp->tg_pt_gp_valid_id = 1;
1444         list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1445                         &su_dev->t10_alua.tg_pt_gps_list);
1446         su_dev->t10_alua.alua_tg_pt_gps_count++;
1447         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1448
1449         return 0;
1450 }
1451
1452 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1453         struct se_port *port)
1454 {
1455         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1456
1457         tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1458                                 GFP_KERNEL);
1459         if (!tg_pt_gp_mem) {
1460                 pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1461                 return ERR_PTR(-ENOMEM);
1462         }
1463         INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1464         spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1465         atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1466
1467         tg_pt_gp_mem->tg_pt = port;
1468         port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1469
1470         return tg_pt_gp_mem;
1471 }
1472
1473 void core_alua_free_tg_pt_gp(
1474         struct t10_alua_tg_pt_gp *tg_pt_gp)
1475 {
1476         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1477         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1478         /*
1479          * Once we have reached this point, config_item_put() has already
1480          * been called from target_core_alua_drop_tg_pt_gp().
1481          *
1482          * Here we remove *tg_pt_gp from the global list so that
1483          * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1484          * can be made while we are releasing struct t10_alua_tg_pt_gp.
1485          */
1486         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1487         list_del(&tg_pt_gp->tg_pt_gp_list);
1488         su_dev->t10_alua.alua_tg_pt_gps_counter--;
1489         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1490         /*
1491          * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1492          * core_alua_get_tg_pt_gp_by_name() in
1493          * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1494          * to be released with core_alua_put_tg_pt_gp_from_name().
1495          */
1496         while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1497                 cpu_relax();
1498         /*
1499          * Release reference to struct t10_alua_tg_pt_gp from all associated
1500          * struct se_port.
1501          */
1502         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1503         list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1504                         &tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1505                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1506                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1507                         tg_pt_gp->tg_pt_gp_members--;
1508                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1509                 }
1510                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1511                 /*
1512                  * tg_pt_gp_mem is associated with a single
1513                  * se_port->sep_alua_tg_pt_gp_mem, and is released via
1514                  * core_alua_free_tg_pt_gp_mem().
1515                  *
1516                  * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1517                  * assume we want to re-assocate a given tg_pt_gp_mem with
1518                  * default_tg_pt_gp.
1519                  */
1520                 spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1521                 if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
1522                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1523                                         su_dev->t10_alua.default_tg_pt_gp);
1524                 } else
1525                         tg_pt_gp_mem->tg_pt_gp = NULL;
1526                 spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1527
1528                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1529         }
1530         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1531
1532         kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1533 }
1534
1535 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1536 {
1537         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1538         struct t10_alua *alua = &su_dev->t10_alua;
1539         struct t10_alua_tg_pt_gp *tg_pt_gp;
1540         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1541
1542         if (alua->alua_type != SPC3_ALUA_EMULATED)
1543                 return;
1544
1545         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1546         if (!tg_pt_gp_mem)
1547                 return;
1548
1549         while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1550                 cpu_relax();
1551
1552         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1553         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1554         if (tg_pt_gp) {
1555                 spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1556                 if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1557                         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1558                         tg_pt_gp->tg_pt_gp_members--;
1559                         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1560                 }
1561                 spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1562                 tg_pt_gp_mem->tg_pt_gp = NULL;
1563         }
1564         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1565
1566         kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1567 }
1568
1569 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1570         struct se_subsystem_dev *su_dev,
1571         const char *name)
1572 {
1573         struct t10_alua_tg_pt_gp *tg_pt_gp;
1574         struct config_item *ci;
1575
1576         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1577         list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
1578                         tg_pt_gp_list) {
1579                 if (!tg_pt_gp->tg_pt_gp_valid_id)
1580                         continue;
1581                 ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1582                 if (!strcmp(config_item_name(ci), name)) {
1583                         atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1584                         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1585                         return tg_pt_gp;
1586                 }
1587         }
1588         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1589
1590         return NULL;
1591 }
1592
1593 static void core_alua_put_tg_pt_gp_from_name(
1594         struct t10_alua_tg_pt_gp *tg_pt_gp)
1595 {
1596         struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1597
1598         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1599         atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1600         spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1601 }
1602
1603 /*
1604  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1605  */
1606 void __core_alua_attach_tg_pt_gp_mem(
1607         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1608         struct t10_alua_tg_pt_gp *tg_pt_gp)
1609 {
1610         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1611         tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1612         tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1613         list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1614                         &tg_pt_gp->tg_pt_gp_mem_list);
1615         tg_pt_gp->tg_pt_gp_members++;
1616         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1617 }
1618
1619 /*
1620  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1621  */
1622 static void __core_alua_drop_tg_pt_gp_mem(
1623         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1624         struct t10_alua_tg_pt_gp *tg_pt_gp)
1625 {
1626         spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1627         list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1628         tg_pt_gp_mem->tg_pt_gp = NULL;
1629         tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1630         tg_pt_gp->tg_pt_gp_members--;
1631         spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1632 }
1633
1634 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1635 {
1636         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1637         struct config_item *tg_pt_ci;
1638         struct t10_alua *alua = &su_dev->t10_alua;
1639         struct t10_alua_tg_pt_gp *tg_pt_gp;
1640         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1641         ssize_t len = 0;
1642
1643         if (alua->alua_type != SPC3_ALUA_EMULATED)
1644                 return len;
1645
1646         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1647         if (!tg_pt_gp_mem)
1648                 return len;
1649
1650         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1651         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1652         if (tg_pt_gp) {
1653                 tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1654                 len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1655                         " %hu\nTG Port Primary Access State: %s\nTG Port "
1656                         "Primary Access Status: %s\nTG Port Secondary Access"
1657                         " State: %s\nTG Port Secondary Access Status: %s\n",
1658                         config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1659                         core_alua_dump_state(atomic_read(
1660                                         &tg_pt_gp->tg_pt_gp_alua_access_state)),
1661                         core_alua_dump_status(
1662                                 tg_pt_gp->tg_pt_gp_alua_access_status),
1663                         (atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1664                         "Offline" : "None",
1665                         core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1666         }
1667         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1668
1669         return len;
1670 }
1671
1672 ssize_t core_alua_store_tg_pt_gp_info(
1673         struct se_port *port,
1674         const char *page,
1675         size_t count)
1676 {
1677         struct se_portal_group *tpg;
1678         struct se_lun *lun;
1679         struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1680         struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1681         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1682         unsigned char buf[TG_PT_GROUP_NAME_BUF];
1683         int move = 0;
1684
1685         tpg = port->sep_tpg;
1686         lun = port->sep_lun;
1687
1688         if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
1689                 pr_warn("SPC3_ALUA_EMULATED not enabled for"
1690                         " %s/tpgt_%hu/%s\n", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1691                         tpg->se_tpg_tfo->tpg_get_tag(tpg),
1692                         config_item_name(&lun->lun_group.cg_item));
1693                 return -EINVAL;
1694         }
1695
1696         if (count > TG_PT_GROUP_NAME_BUF) {
1697                 pr_err("ALUA Target Port Group alias too large!\n");
1698                 return -EINVAL;
1699         }
1700         memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1701         memcpy(buf, page, count);
1702         /*
1703          * Any ALUA target port group alias besides "NULL" means we will be
1704          * making a new group association.
1705          */
1706         if (strcmp(strstrip(buf), "NULL")) {
1707                 /*
1708                  * core_alua_get_tg_pt_gp_by_name() will increment reference to
1709                  * struct t10_alua_tg_pt_gp.  This reference is released with
1710                  * core_alua_put_tg_pt_gp_from_name() below.
1711                  */
1712                 tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(su_dev,
1713                                         strstrip(buf));
1714                 if (!tg_pt_gp_new)
1715                         return -ENODEV;
1716         }
1717         tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1718         if (!tg_pt_gp_mem) {
1719                 if (tg_pt_gp_new)
1720                         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1721                 pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
1722                 return -EINVAL;
1723         }
1724
1725         spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1726         tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1727         if (tg_pt_gp) {
1728                 /*
1729                  * Clearing an existing tg_pt_gp association, and replacing
1730                  * with the default_tg_pt_gp.
1731                  */
1732                 if (!tg_pt_gp_new) {
1733                         pr_debug("Target_Core_ConfigFS: Moving"
1734                                 " %s/tpgt_%hu/%s from ALUA Target Port Group:"
1735                                 " alua/%s, ID: %hu back to"
1736                                 " default_tg_pt_gp\n",
1737                                 tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1738                                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1739                                 config_item_name(&lun->lun_group.cg_item),
1740                                 config_item_name(
1741                                         &tg_pt_gp->tg_pt_gp_group.cg_item),
1742                                 tg_pt_gp->tg_pt_gp_id);
1743
1744                         __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1745                         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1746                                         su_dev->t10_alua.default_tg_pt_gp);
1747                         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1748
1749                         return count;
1750                 }
1751                 /*
1752                  * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1753                  */
1754                 __core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1755                 move = 1;
1756         }
1757         /*
1758          * Associate tg_pt_gp_mem with tg_pt_gp_new.
1759          */
1760         __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1761         spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1762         pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1763                 " Target Port Group: alua/%s, ID: %hu\n", (move) ?
1764                 "Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1765                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
1766                 config_item_name(&lun->lun_group.cg_item),
1767                 config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1768                 tg_pt_gp_new->tg_pt_gp_id);
1769
1770         core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1771         return count;
1772 }
1773
1774 ssize_t core_alua_show_access_type(
1775         struct t10_alua_tg_pt_gp *tg_pt_gp,
1776         char *page)
1777 {
1778         if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1779             (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1780                 return sprintf(page, "Implict and Explict\n");
1781         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1782                 return sprintf(page, "Implict\n");
1783         else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1784                 return sprintf(page, "Explict\n");
1785         else
1786                 return sprintf(page, "None\n");
1787 }
1788
1789 ssize_t core_alua_store_access_type(
1790         struct t10_alua_tg_pt_gp *tg_pt_gp,
1791         const char *page,
1792         size_t count)
1793 {
1794         unsigned long tmp;
1795         int ret;
1796
1797         ret = strict_strtoul(page, 0, &tmp);
1798         if (ret < 0) {
1799                 pr_err("Unable to extract alua_access_type\n");
1800                 return -EINVAL;
1801         }
1802         if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1803                 pr_err("Illegal value for alua_access_type:"
1804                                 " %lu\n", tmp);
1805                 return -EINVAL;
1806         }
1807         if (tmp == 3)
1808                 tg_pt_gp->tg_pt_gp_alua_access_type =
1809                         TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1810         else if (tmp == 2)
1811                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1812         else if (tmp == 1)
1813                 tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1814         else
1815                 tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1816
1817         return count;
1818 }
1819
1820 ssize_t core_alua_show_nonop_delay_msecs(
1821         struct t10_alua_tg_pt_gp *tg_pt_gp,
1822         char *page)
1823 {
1824         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1825 }
1826
1827 ssize_t core_alua_store_nonop_delay_msecs(
1828         struct t10_alua_tg_pt_gp *tg_pt_gp,
1829         const char *page,
1830         size_t count)
1831 {
1832         unsigned long tmp;
1833         int ret;
1834
1835         ret = strict_strtoul(page, 0, &tmp);
1836         if (ret < 0) {
1837                 pr_err("Unable to extract nonop_delay_msecs\n");
1838                 return -EINVAL;
1839         }
1840         if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1841                 pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1842                         " ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1843                         ALUA_MAX_NONOP_DELAY_MSECS);
1844                 return -EINVAL;
1845         }
1846         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1847
1848         return count;
1849 }
1850
1851 ssize_t core_alua_show_trans_delay_msecs(
1852         struct t10_alua_tg_pt_gp *tg_pt_gp,
1853         char *page)
1854 {
1855         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1856 }
1857
1858 ssize_t core_alua_store_trans_delay_msecs(
1859         struct t10_alua_tg_pt_gp *tg_pt_gp,
1860         const char *page,
1861         size_t count)
1862 {
1863         unsigned long tmp;
1864         int ret;
1865
1866         ret = strict_strtoul(page, 0, &tmp);
1867         if (ret < 0) {
1868                 pr_err("Unable to extract trans_delay_msecs\n");
1869                 return -EINVAL;
1870         }
1871         if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1872                 pr_err("Passed trans_delay_msecs: %lu, exceeds"
1873                         " ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1874                         ALUA_MAX_TRANS_DELAY_MSECS);
1875                 return -EINVAL;
1876         }
1877         tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1878
1879         return count;
1880 }
1881
1882 ssize_t core_alua_show_implict_trans_secs(
1883         struct t10_alua_tg_pt_gp *tg_pt_gp,
1884         char *page)
1885 {
1886         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implict_trans_secs);
1887 }
1888
1889 ssize_t core_alua_store_implict_trans_secs(
1890         struct t10_alua_tg_pt_gp *tg_pt_gp,
1891         const char *page,
1892         size_t count)
1893 {
1894         unsigned long tmp;
1895         int ret;
1896
1897         ret = strict_strtoul(page, 0, &tmp);
1898         if (ret < 0) {
1899                 pr_err("Unable to extract implict_trans_secs\n");
1900                 return -EINVAL;
1901         }
1902         if (tmp > ALUA_MAX_IMPLICT_TRANS_SECS) {
1903                 pr_err("Passed implict_trans_secs: %lu, exceeds"
1904                         " ALUA_MAX_IMPLICT_TRANS_SECS: %d\n", tmp,
1905                         ALUA_MAX_IMPLICT_TRANS_SECS);
1906                 return  -EINVAL;
1907         }
1908         tg_pt_gp->tg_pt_gp_implict_trans_secs = (int)tmp;
1909
1910         return count;
1911 }
1912
1913 ssize_t core_alua_show_preferred_bit(
1914         struct t10_alua_tg_pt_gp *tg_pt_gp,
1915         char *page)
1916 {
1917         return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1918 }
1919
1920 ssize_t core_alua_store_preferred_bit(
1921         struct t10_alua_tg_pt_gp *tg_pt_gp,
1922         const char *page,
1923         size_t count)
1924 {
1925         unsigned long tmp;
1926         int ret;
1927
1928         ret = strict_strtoul(page, 0, &tmp);
1929         if (ret < 0) {
1930                 pr_err("Unable to extract preferred ALUA value\n");
1931                 return -EINVAL;
1932         }
1933         if ((tmp != 0) && (tmp != 1)) {
1934                 pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1935                 return -EINVAL;
1936         }
1937         tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1938
1939         return count;
1940 }
1941
1942 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1943 {
1944         if (!lun->lun_sep)
1945                 return -ENODEV;
1946
1947         return sprintf(page, "%d\n",
1948                 atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1949 }
1950
1951 ssize_t core_alua_store_offline_bit(
1952         struct se_lun *lun,
1953         const char *page,
1954         size_t count)
1955 {
1956         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1957         unsigned long tmp;
1958         int ret;
1959
1960         if (!lun->lun_sep)
1961                 return -ENODEV;
1962
1963         ret = strict_strtoul(page, 0, &tmp);
1964         if (ret < 0) {
1965                 pr_err("Unable to extract alua_tg_pt_offline value\n");
1966                 return -EINVAL;
1967         }
1968         if ((tmp != 0) && (tmp != 1)) {
1969                 pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1970                                 tmp);
1971                 return -EINVAL;
1972         }
1973         tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1974         if (!tg_pt_gp_mem) {
1975                 pr_err("Unable to locate *tg_pt_gp_mem\n");
1976                 return -EINVAL;
1977         }
1978
1979         ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1980                         lun->lun_sep, 0, (int)tmp);
1981         if (ret < 0)
1982                 return -EINVAL;
1983
1984         return count;
1985 }
1986
1987 ssize_t core_alua_show_secondary_status(
1988         struct se_lun *lun,
1989         char *page)
1990 {
1991         return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1992 }
1993
1994 ssize_t core_alua_store_secondary_status(
1995         struct se_lun *lun,
1996         const char *page,
1997         size_t count)
1998 {
1999         unsigned long tmp;
2000         int ret;
2001
2002         ret = strict_strtoul(page, 0, &tmp);
2003         if (ret < 0) {
2004                 pr_err("Unable to extract alua_tg_pt_status\n");
2005                 return -EINVAL;
2006         }
2007         if ((tmp != ALUA_STATUS_NONE) &&
2008             (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
2009             (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
2010                 pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2011                                 tmp);
2012                 return -EINVAL;
2013         }
2014         lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
2015
2016         return count;
2017 }
2018
2019 ssize_t core_alua_show_secondary_write_metadata(
2020         struct se_lun *lun,
2021         char *page)
2022 {
2023         return sprintf(page, "%d\n",
2024                         lun->lun_sep->sep_tg_pt_secondary_write_md);
2025 }
2026
2027 ssize_t core_alua_store_secondary_write_metadata(
2028         struct se_lun *lun,
2029         const char *page,
2030         size_t count)
2031 {
2032         unsigned long tmp;
2033         int ret;
2034
2035         ret = strict_strtoul(page, 0, &tmp);
2036         if (ret < 0) {
2037                 pr_err("Unable to extract alua_tg_pt_write_md\n");
2038                 return -EINVAL;
2039         }
2040         if ((tmp != 0) && (tmp != 1)) {
2041                 pr_err("Illegal value for alua_tg_pt_write_md:"
2042                                 " %lu\n", tmp);
2043                 return -EINVAL;
2044         }
2045         lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
2046
2047         return count;
2048 }
2049
2050 int core_setup_alua(struct se_device *dev, int force_pt)
2051 {
2052         struct se_subsystem_dev *su_dev = dev->se_sub_dev;
2053         struct t10_alua *alua = &su_dev->t10_alua;
2054         struct t10_alua_lu_gp_member *lu_gp_mem;
2055         /*
2056          * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
2057          * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
2058          * cause a problem because libata and some SATA RAID HBAs appear
2059          * under Linux/SCSI, but emulate SCSI logic themselves.
2060          */
2061         if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
2062             !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
2063                 alua->alua_type = SPC_ALUA_PASSTHROUGH;
2064                 alua->alua_state_check = &core_alua_state_check_nop;
2065                 pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
2066                         " emulation\n", dev->transport->name);
2067                 return 0;
2068         }
2069         /*
2070          * If SPC-3 or above is reported by real or emulated struct se_device,
2071          * use emulated ALUA.
2072          */
2073         if (dev->transport->get_device_rev(dev) >= SCSI_3) {
2074                 pr_debug("%s: Enabling ALUA Emulation for SPC-3"
2075                         " device\n", dev->transport->name);
2076                 /*
2077                  * Associate this struct se_device with the default ALUA
2078                  * LUN Group.
2079                  */
2080                 lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2081                 if (IS_ERR(lu_gp_mem))
2082                         return PTR_ERR(lu_gp_mem);
2083
2084                 alua->alua_type = SPC3_ALUA_EMULATED;
2085                 alua->alua_state_check = &core_alua_state_check;
2086                 spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2087                 __core_alua_attach_lu_gp_mem(lu_gp_mem,
2088                                 default_lu_gp);
2089                 spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2090
2091                 pr_debug("%s: Adding to default ALUA LU Group:"
2092                         " core/alua/lu_gps/default_lu_gp\n",
2093                         dev->transport->name);
2094         } else {
2095                 alua->alua_type = SPC2_ALUA_DISABLED;
2096                 alua->alua_state_check = &core_alua_state_check_nop;
2097                 pr_debug("%s: Disabling ALUA Emulation for SPC-2"
2098                         " device\n", dev->transport->name);
2099         }
2100
2101         return 0;
2102 }