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