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