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