drivers/scsi/device_handler/scsi_dh_rdac.c

   1 /*
   2  * LSI/Engenio/NetApp E-Series RDAC SCSI Device Handler
   3  *
   4  * Copyright (C) 2005 Mike Christie. All rights reserved.
   5  * Copyright (C) Chandra Seetharaman, IBM Corp. 2007
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  *
  21  */
  22 #include <scsi/scsi.h>
  23 #include <scsi/scsi_eh.h>
  24 #include <scsi/scsi_dh.h>
  25 #include <linux/workqueue.h>
  26 #include <linux/slab.h>
  27 #include <linux/module.h>
  28
  29 #define RDAC_NAME "rdac"
  30 #define RDAC_RETRY_COUNT 5
  31
  32 /*
  33  * LSI mode page stuff
  34  *
  35  * These struct definitions and the forming of the
  36  * mode page were taken from the LSI RDAC 2.4 GPL'd
  37  * driver, and then converted to Linux conventions.
  38  */
  39 #define RDAC_QUIESCENCE_TIME 20
  40 /*
  41  * Page Codes
  42  */
  43 #define RDAC_PAGE_CODE_REDUNDANT_CONTROLLER 0x2c
  44
  45 /*
  46  * Controller modes definitions
  47  */
  48 #define RDAC_MODE_TRANSFER_SPECIFIED_LUNS       0x02
  49
  50 /*
  51  * RDAC Options field
  52  */
  53 #define RDAC_FORCED_QUIESENCE 0x02
  54
  55 #define RDAC_TIMEOUT    (60 * HZ)
  56 #define RDAC_RETRIES    3
  57
  58 struct rdac_mode_6_hdr {
  59         u8      data_len;
  60         u8      medium_type;
  61         u8      device_params;
  62         u8      block_desc_len;
  63 };
  64
  65 struct rdac_mode_10_hdr {
  66         u16     data_len;
  67         u8      medium_type;
  68         u8      device_params;
  69         u16     reserved;
  70         u16     block_desc_len;
  71 };
  72
  73 struct rdac_mode_common {
  74         u8      controller_serial[16];
  75         u8      alt_controller_serial[16];
  76         u8      rdac_mode[2];
  77         u8      alt_rdac_mode[2];
  78         u8      quiescence_timeout;
  79         u8      rdac_options;
  80 };
  81
  82 struct rdac_pg_legacy {
  83         struct rdac_mode_6_hdr hdr;
  84         u8      page_code;
  85         u8      page_len;
  86         struct rdac_mode_common common;
  87 #define MODE6_MAX_LUN   32
  88         u8      lun_table[MODE6_MAX_LUN];
  89         u8      reserved2[32];
  90         u8      reserved3;
  91         u8      reserved4;
  92 };
  93
  94 struct rdac_pg_expanded {
  95         struct rdac_mode_10_hdr hdr;
  96         u8      page_code;
  97         u8      subpage_code;
  98         u8      page_len[2];
  99         struct rdac_mode_common common;
 100         u8      lun_table[256];
 101         u8      reserved3;
 102         u8      reserved4;
 103 };
 104
 105 struct c9_inquiry {
 106         u8      peripheral_info;
 107         u8      page_code;      /* 0xC9 */
 108         u8      reserved1;
 109         u8      page_len;
 110         u8      page_id[4];     /* "vace" */
 111         u8      avte_cvp;
 112         u8      path_prio;
 113         u8      reserved2[38];
 114 };
 115
 116 #define SUBSYS_ID_LEN   16
 117 #define SLOT_ID_LEN     2
 118 #define ARRAY_LABEL_LEN 31
 119
 120 struct c4_inquiry {
 121         u8      peripheral_info;
 122         u8      page_code;      /* 0xC4 */
 123         u8      reserved1;
 124         u8      page_len;
 125         u8      page_id[4];     /* "subs" */
 126         u8      subsys_id[SUBSYS_ID_LEN];
 127         u8      revision[4];
 128         u8      slot_id[SLOT_ID_LEN];
 129         u8      reserved[2];
 130 };
 131
 132 #define UNIQUE_ID_LEN 16
 133 struct c8_inquiry {
 134         u8      peripheral_info;
 135         u8      page_code; /* 0xC8 */
 136         u8      reserved1;
 137         u8      page_len;
 138         u8      page_id[4]; /* "edid" */
 139         u8      reserved2[3];
 140         u8      vol_uniq_id_len;
 141         u8      vol_uniq_id[16];
 142         u8      vol_user_label_len;
 143         u8      vol_user_label[60];
 144         u8      array_uniq_id_len;
 145         u8      array_unique_id[UNIQUE_ID_LEN];
 146         u8      array_user_label_len;
 147         u8      array_user_label[60];
 148         u8      lun[8];
 149 };
 150
 151 struct rdac_controller {
 152         u8                      array_id[UNIQUE_ID_LEN];
 153         int                     use_ms10;
 154         struct kref             kref;
 155         struct list_head        node; /* list of all controllers */
 156         union                   {
 157                 struct rdac_pg_legacy legacy;
 158                 struct rdac_pg_expanded expanded;
 159         } mode_select;
 160         u8      index;
 161         u8      array_name[ARRAY_LABEL_LEN];
 162         struct Scsi_Host        *host;
 163         spinlock_t              ms_lock;
 164         int                     ms_queued;
 165         struct work_struct      ms_work;
 166         struct scsi_device      *ms_sdev;
 167         struct list_head        ms_head;
 168         struct list_head        dh_list;
 169 };
 170
 171 struct c2_inquiry {
 172         u8      peripheral_info;
 173         u8      page_code;      /* 0xC2 */
 174         u8      reserved1;
 175         u8      page_len;
 176         u8      page_id[4];     /* "swr4" */
 177         u8      sw_version[3];
 178         u8      sw_date[3];
 179         u8      features_enabled;
 180         u8      max_lun_supported;
 181         u8      partitions[239]; /* Total allocation length should be 0xFF */
 182 };
 183
 184 struct rdac_dh_data {
 185         struct list_head        node;
 186         struct rdac_controller  *ctlr;
 187         struct scsi_device      *sdev;
 188 #define UNINITIALIZED_LUN       (1 << 8)
 189         unsigned                lun;
 190
 191 #define RDAC_MODE               0
 192 #define RDAC_MODE_AVT           1
 193 #define RDAC_MODE_IOSHIP        2
 194         unsigned char           mode;
 195
 196 #define RDAC_STATE_ACTIVE       0
 197 #define RDAC_STATE_PASSIVE      1
 198         unsigned char           state;
 199
 200 #define RDAC_LUN_UNOWNED        0
 201 #define RDAC_LUN_OWNED          1
 202         char                    lun_state;
 203
 204 #define RDAC_PREFERRED          0
 205 #define RDAC_NON_PREFERRED      1
 206         char                    preferred;
 207
 208         union                   {
 209                 struct c2_inquiry c2;
 210                 struct c4_inquiry c4;
 211                 struct c8_inquiry c8;
 212                 struct c9_inquiry c9;
 213         } inq;
 214 };
 215
 216 static const char *mode[] = {
 217         "RDAC",
 218         "AVT",
 219         "IOSHIP",
 220 };
 221 static const char *lun_state[] =
 222 {
 223         "unowned",
 224         "owned",
 225 };
 226
 227 struct rdac_queue_data {
 228         struct list_head        entry;
 229         struct rdac_dh_data     *h;
 230         activate_complete       callback_fn;
 231         void                    *callback_data;
 232 };
 233
 234 static LIST_HEAD(ctlr_list);
 235 static DEFINE_SPINLOCK(list_lock);
 236 static struct workqueue_struct *kmpath_rdacd;
 237 static void send_mode_select(struct work_struct *work);
 238
 239 /*
 240  * module parameter to enable rdac debug logging.
 241  * 2 bits for each type of logging, only two types defined for now
 242  * Can be enhanced if required at later point
 243  */
 244 static int rdac_logging = 1;
 245 module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
 246 MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
 247                 "Default is 1 - failover logging enabled, "
 248                 "set it to 0xF to enable all the logs");
 249
 250 #define RDAC_LOG_FAILOVER       0
 251 #define RDAC_LOG_SENSE          2
 252
 253 #define RDAC_LOG_BITS           2
 254
 255 #define RDAC_LOG_LEVEL(SHIFT)  \
 256         ((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
 257
 258 #define RDAC_LOG(SHIFT, sdev, f, arg...) \
 259 do { \
 260         if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
 261                 sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
 262 } while (0);
 263
 264 static unsigned int rdac_failover_get(struct rdac_controller *ctlr,
 265                                       struct list_head *list,
 266                                       unsigned char *cdb)
 267 {
 268         struct rdac_mode_common *common;
 269         unsigned data_size;
 270         struct rdac_queue_data *qdata;
 271         u8 *lun_table;
 272
 273         if (ctlr->use_ms10) {
 274                 struct rdac_pg_expanded *rdac_pg;
 275
 276                 data_size = sizeof(struct rdac_pg_expanded);
 277                 rdac_pg = &ctlr->mode_select.expanded;
 278                 memset(rdac_pg, 0, data_size);
 279                 common = &rdac_pg->common;
 280                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
 281                 rdac_pg->subpage_code = 0x1;
 282                 rdac_pg->page_len[0] = 0x01;
 283                 rdac_pg->page_len[1] = 0x28;
 284                 lun_table = rdac_pg->lun_table;
 285         } else {
 286                 struct rdac_pg_legacy *rdac_pg;
 287
 288                 data_size = sizeof(struct rdac_pg_legacy);
 289                 rdac_pg = &ctlr->mode_select.legacy;
 290                 memset(rdac_pg, 0, data_size);
 291                 common = &rdac_pg->common;
 292                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
 293                 rdac_pg->page_len = 0x68;
 294                 lun_table = rdac_pg->lun_table;
 295         }
 296         common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
 297         common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
 298         common->rdac_options = RDAC_FORCED_QUIESENCE;
 299
 300         list_for_each_entry(qdata, list, entry) {
 301                 lun_table[qdata->h->lun] = 0x81;
 302         }
 303
 304         /* Prepare the command. */
 305         if (ctlr->use_ms10) {
 306                 cdb[0] = MODE_SELECT_10;
 307                 cdb[7] = data_size >> 8;
 308                 cdb[8] = data_size & 0xff;
 309         } else {
 310                 cdb[0] = MODE_SELECT;
 311                 cdb[4] = data_size;
 312         }
 313
 314         return data_size;
 315 }
 316
 317 static void release_controller(struct kref *kref)
 318 {
 319         struct rdac_controller *ctlr;
 320         ctlr = container_of(kref, struct rdac_controller, kref);
 321
 322         list_del(&ctlr->node);
 323         kfree(ctlr);
 324 }
 325
 326 static struct rdac_controller *get_controller(int index, char *array_name,
 327                         u8 *array_id, struct scsi_device *sdev)
 328 {
 329         struct rdac_controller *ctlr, *tmp;
 330
 331         list_for_each_entry(tmp, &ctlr_list, node) {
 332                 if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
 333                           (tmp->index == index) &&
 334                           (tmp->host == sdev->host)) {
 335                         kref_get(&tmp->kref);
 336                         return tmp;
 337                 }
 338         }
 339         ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
 340         if (!ctlr)
 341                 return NULL;
 342
 343         /* initialize fields of controller */
 344         memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
 345         ctlr->index = index;
 346         ctlr->host = sdev->host;
 347         memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
 348
 349         kref_init(&ctlr->kref);
 350         ctlr->use_ms10 = -1;
 351         ctlr->ms_queued = 0;
 352         ctlr->ms_sdev = NULL;
 353         spin_lock_init(&ctlr->ms_lock);
 354         INIT_WORK(&ctlr->ms_work, send_mode_select);
 355         INIT_LIST_HEAD(&ctlr->ms_head);
 356         list_add(&ctlr->node, &ctlr_list);
 357         INIT_LIST_HEAD(&ctlr->dh_list);
 358
 359         return ctlr;
 360 }
 361
 362 static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
 363                         char *array_name, u8 *array_id)
 364 {
 365         int err = SCSI_DH_IO, i;
 366         struct c8_inquiry *inqp = &h->inq.c8;
 367
 368         if (!scsi_get_vpd_page(sdev, 0xC8, (unsigned char *)inqp,
 369                                sizeof(struct c8_inquiry))) {
 370                 if (inqp->page_code != 0xc8)
 371                         return SCSI_DH_NOSYS;
 372                 if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
 373                     inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
 374                         return SCSI_DH_NOSYS;
 375                 h->lun = inqp->lun[7]; /* Uses only the last byte */
 376
 377                 for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
 378                         *(array_name+i) = inqp->array_user_label[(2*i)+1];
 379
 380                 *(array_name+ARRAY_LABEL_LEN-1) = '\0';
 381                 memset(array_id, 0, UNIQUE_ID_LEN);
 382                 memcpy(array_id, inqp->array_unique_id, inqp->array_uniq_id_len);
 383                 err = SCSI_DH_OK;
 384         }
 385         return err;
 386 }
 387
 388 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
 389 {
 390         int err = SCSI_DH_IO, access_state;
 391         struct rdac_dh_data *tmp;
 392         struct c9_inquiry *inqp = &h->inq.c9;
 393
 394         h->state = RDAC_STATE_ACTIVE;
 395         if (!scsi_get_vpd_page(sdev, 0xC9, (unsigned char *)inqp,
 396                                sizeof(struct c9_inquiry))) {
 397                 /* detect the operating mode */
 398                 if ((inqp->avte_cvp >> 5) & 0x1)
 399                         h->mode = RDAC_MODE_IOSHIP; /* LUN in IOSHIP mode */
 400                 else if (inqp->avte_cvp >> 7)
 401                         h->mode = RDAC_MODE_AVT; /* LUN in AVT mode */
 402                 else
 403                         h->mode = RDAC_MODE; /* LUN in RDAC mode */
 404
 405                 /* Update ownership */
 406                 if (inqp->avte_cvp & 0x1) {
 407                         h->lun_state = RDAC_LUN_OWNED;
 408                         access_state = SCSI_ACCESS_STATE_OPTIMAL;
 409                 } else {
 410                         h->lun_state = RDAC_LUN_UNOWNED;
 411                         if (h->mode == RDAC_MODE) {
 412                                 h->state = RDAC_STATE_PASSIVE;
 413                                 access_state = SCSI_ACCESS_STATE_STANDBY;
 414                         } else
 415                                 access_state = SCSI_ACCESS_STATE_ACTIVE;
 416                 }
 417
 418                 /* Update path prio*/
 419                 if (inqp->path_prio & 0x1) {
 420                         h->preferred = RDAC_PREFERRED;
 421                         access_state |= SCSI_ACCESS_STATE_PREFERRED;
 422                 } else
 423                         h->preferred = RDAC_NON_PREFERRED;
 424                 rcu_read_lock();
 425                 list_for_each_entry_rcu(tmp, &h->ctlr->dh_list, node) {
 426                         /* h->sdev should always be valid */
 427                         BUG_ON(!tmp->sdev);
 428                         tmp->sdev->access_state = access_state;
 429                 }
 430                 rcu_read_unlock();
 431                 err = SCSI_DH_OK;
 432         }
 433
 434         return err;
 435 }
 436
 437 static int initialize_controller(struct scsi_device *sdev,
 438                 struct rdac_dh_data *h, char *array_name, u8 *array_id)
 439 {
 440         int err = SCSI_DH_IO, index;
 441         struct c4_inquiry *inqp = &h->inq.c4;
 442
 443         if (!scsi_get_vpd_page(sdev, 0xC4, (unsigned char *)inqp,
 444                                sizeof(struct c4_inquiry))) {
 445                 /* get the controller index */
 446                 if (inqp->slot_id[1] == 0x31)
 447                         index = 0;
 448                 else
 449                         index = 1;
 450
 451                 spin_lock(&list_lock);
 452                 h->ctlr = get_controller(index, array_name, array_id, sdev);
 453                 if (!h->ctlr)
 454                         err = SCSI_DH_RES_TEMP_UNAVAIL;
 455                 else {
 456                         h->sdev = sdev;
 457                         list_add_rcu(&h->node, &h->ctlr->dh_list);
 458                 }
 459                 spin_unlock(&list_lock);
 460                 err = SCSI_DH_OK;
 461         }
 462         return err;
 463 }
 464
 465 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
 466 {
 467         int err = SCSI_DH_IO;
 468         struct c2_inquiry *inqp = &h->inq.c2;
 469
 470         if (!scsi_get_vpd_page(sdev, 0xC2, (unsigned char *)inqp,
 471                                sizeof(struct c2_inquiry))) {
 472                 /*
 473                  * If more than MODE6_MAX_LUN luns are supported, use
 474                  * mode select 10
 475                  */
 476                 if (inqp->max_lun_supported >= MODE6_MAX_LUN)
 477                         h->ctlr->use_ms10 = 1;
 478                 else
 479                         h->ctlr->use_ms10 = 0;
 480                 err = SCSI_DH_OK;
 481         }
 482         return err;
 483 }
 484
 485 static int mode_select_handle_sense(struct scsi_device *sdev,
 486                                     struct scsi_sense_hdr *sense_hdr)
 487 {
 488         struct rdac_dh_data *h = sdev->handler_data;
 489
 490         if (!scsi_sense_valid(sense_hdr))
 491                 return SCSI_DH_IO;
 492
 493         RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 494                 "MODE_SELECT returned with sense %02x/%02x/%02x",
 495                 (char *) h->ctlr->array_name, h->ctlr->index,
 496                 sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 497
 498         return SCSI_DH_IO;
 499 }
 500
 501 static void send_mode_select(struct work_struct *work)
 502 {
 503         struct rdac_controller *ctlr =
 504                 container_of(work, struct rdac_controller, ms_work);
 505         struct scsi_device *sdev = ctlr->ms_sdev;
 506         struct rdac_dh_data *h = sdev->handler_data;
 507         int rc, err;
 508         struct rdac_queue_data *tmp, *qdata;
 509         LIST_HEAD(list);
 510         unsigned char cdb[MAX_COMMAND_SIZE];
 511         struct scsi_sense_hdr sshdr;
 512         unsigned int data_size;
 513         blk_opf_t opf = REQ_OP_DRV_OUT | REQ_FAILFAST_DEV |
 514                                 REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER;
 515         struct scsi_failure failure_defs[] = {
 516                 {
 517                         .sense = NO_SENSE,
 518                         .asc = SCMD_FAILURE_ASC_ANY,
 519                         .ascq = SCMD_FAILURE_ASCQ_ANY,
 520                         .result = SAM_STAT_CHECK_CONDITION,
 521                 },
 522                 {
 523                         .sense = ABORTED_COMMAND,
 524                         .asc = SCMD_FAILURE_ASC_ANY,
 525                         .ascq = SCMD_FAILURE_ASCQ_ANY,
 526                         .result = SAM_STAT_CHECK_CONDITION,
 527                 },
 528                 {
 529                         .sense = UNIT_ATTENTION,
 530                         .asc = SCMD_FAILURE_ASC_ANY,
 531                         .ascq = SCMD_FAILURE_ASCQ_ANY,
 532                         .result = SAM_STAT_CHECK_CONDITION,
 533                 },
 534                 /* LUN Not Ready and is in the Process of Becoming Ready */
 535                 {
 536                         .sense = NOT_READY,
 537                         .asc = 0x04,
 538                         .ascq = 0x01,
 539                         .result = SAM_STAT_CHECK_CONDITION,
 540                 },
 541                 /* Command Lock contention */
 542                 {
 543                         .sense = ILLEGAL_REQUEST,
 544                         .asc = 0x91,
 545                         .ascq = 0x36,
 546                         .allowed = SCMD_FAILURE_NO_LIMIT,
 547                         .result = SAM_STAT_CHECK_CONDITION,
 548                 },
 549                 {}
 550         };
 551         struct scsi_failures failures = {
 552                 .total_allowed = RDAC_RETRY_COUNT,
 553                 .failure_definitions = failure_defs,
 554         };
 555         const struct scsi_exec_args exec_args = {
 556                 .sshdr = &sshdr,
 557                 .failures = &failures,
 558         };
 559
 560         spin_lock(&ctlr->ms_lock);
 561         list_splice_init(&ctlr->ms_head, &list);
 562         ctlr->ms_queued = 0;
 563         ctlr->ms_sdev = NULL;
 564         spin_unlock(&ctlr->ms_lock);
 565
 566         memset(cdb, 0, sizeof(cdb));
 567
 568         data_size = rdac_failover_get(ctlr, &list, cdb);
 569
 570         RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, queueing MODE_SELECT command",
 571                 (char *)h->ctlr->array_name, h->ctlr->index);
 572
 573         rc = scsi_execute_cmd(sdev, cdb, opf, &h->ctlr->mode_select, data_size,
 574                               RDAC_TIMEOUT * HZ, RDAC_RETRIES, &exec_args);
 575         if (!rc) {
 576                 h->state = RDAC_STATE_ACTIVE;
 577                 RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 578                                 "MODE_SELECT completed",
 579                                 (char *) h->ctlr->array_name, h->ctlr->index);
 580                 err = SCSI_DH_OK;
 581         } else if (rc < 0) {
 582                 err = SCSI_DH_IO;
 583         } else {
 584                 err = mode_select_handle_sense(sdev, &sshdr);
 585         }
 586
 587         list_for_each_entry_safe(qdata, tmp, &list, entry) {
 588                 list_del(&qdata->entry);
 589                 if (err == SCSI_DH_OK)
 590                         qdata->h->state = RDAC_STATE_ACTIVE;
 591                 if (qdata->callback_fn)
 592                         qdata->callback_fn(qdata->callback_data, err);
 593                 kfree(qdata);
 594         }
 595         return;
 596 }
 597
 598 static int queue_mode_select(struct scsi_device *sdev,
 599                                 activate_complete fn, void *data)
 600 {
 601         struct rdac_queue_data *qdata;
 602         struct rdac_controller *ctlr;
 603
 604         qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
 605         if (!qdata)
 606                 return SCSI_DH_RETRY;
 607
 608         qdata->h = sdev->handler_data;
 609         qdata->callback_fn = fn;
 610         qdata->callback_data = data;
 611
 612         ctlr = qdata->h->ctlr;
 613         spin_lock(&ctlr->ms_lock);
 614         list_add_tail(&qdata->entry, &ctlr->ms_head);
 615         if (!ctlr->ms_queued) {
 616                 ctlr->ms_queued = 1;
 617                 ctlr->ms_sdev = sdev;
 618                 queue_work(kmpath_rdacd, &ctlr->ms_work);
 619         }
 620         spin_unlock(&ctlr->ms_lock);
 621         return SCSI_DH_OK;
 622 }
 623
 624 static int rdac_activate(struct scsi_device *sdev,
 625                         activate_complete fn, void *data)
 626 {
 627         struct rdac_dh_data *h = sdev->handler_data;
 628         int err = SCSI_DH_OK;
 629         int act = 0;
 630
 631         err = check_ownership(sdev, h);
 632         if (err != SCSI_DH_OK)
 633                 goto done;
 634
 635         switch (h->mode) {
 636         case RDAC_MODE:
 637                 if (h->lun_state == RDAC_LUN_UNOWNED)
 638                         act = 1;
 639                 break;
 640         case RDAC_MODE_IOSHIP:
 641                 if ((h->lun_state == RDAC_LUN_UNOWNED) &&
 642                     (h->preferred == RDAC_PREFERRED))
 643                         act = 1;
 644                 break;
 645         default:
 646                 break;
 647         }
 648
 649         if (act) {
 650                 err = queue_mode_select(sdev, fn, data);
 651                 if (err == SCSI_DH_OK)
 652                         return 0;
 653         }
 654 done:
 655         if (fn)
 656                 fn(data, err);
 657         return 0;
 658 }
 659
 660 static blk_status_t rdac_prep_fn(struct scsi_device *sdev, struct request *req)
 661 {
 662         struct rdac_dh_data *h = sdev->handler_data;
 663
 664         if (h->state != RDAC_STATE_ACTIVE) {
 665                 req->rq_flags |= RQF_QUIET;
 666                 return BLK_STS_IOERR;
 667         }
 668
 669         return BLK_STS_OK;
 670 }
 671
 672 static enum scsi_disposition rdac_check_sense(struct scsi_device *sdev,
 673                                               struct scsi_sense_hdr *sense_hdr)
 674 {
 675         struct rdac_dh_data *h = sdev->handler_data;
 676
 677         RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
 678                         "I/O returned with sense %02x/%02x/%02x",
 679                         (char *) h->ctlr->array_name, h->ctlr->index,
 680                         sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 681
 682         switch (sense_hdr->sense_key) {
 683         case NOT_READY:
 684                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
 685                         /* LUN Not Ready - Logical Unit Not Ready and is in
 686                         * the process of becoming ready
 687                         * Just retry.
 688                         */
 689                         return ADD_TO_MLQUEUE;
 690                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
 691                         /* LUN Not Ready - Storage firmware incompatible
 692                          * Manual code synchonisation required.
 693                          *
 694                          * Nothing we can do here. Try to bypass the path.
 695                          */
 696                         return SUCCESS;
 697                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
 698                         /* LUN Not Ready - Quiescense in progress
 699                          *
 700                          * Just retry and wait.
 701                          */
 702                         return ADD_TO_MLQUEUE;
 703                 if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
 704                         /* LUN Not Ready - Quiescense in progress
 705                          * or has been achieved
 706                          * Just retry.
 707                          */
 708                         return ADD_TO_MLQUEUE;
 709                 break;
 710         case ILLEGAL_REQUEST:
 711                 if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
 712                         /* Invalid Request - Current Logical Unit Ownership.
 713                          * Controller is not the current owner of the LUN,
 714                          * Fail the path, so that the other path be used.
 715                          */
 716                         h->state = RDAC_STATE_PASSIVE;
 717                         return SUCCESS;
 718                 }
 719                 break;
 720         case UNIT_ATTENTION:
 721                 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 722                         /*
 723                          * Power On, Reset, or Bus Device Reset, just retry.
 724                          */
 725                         return ADD_TO_MLQUEUE;
 726                 if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
 727                         /*
 728                          * Quiescence in progress , just retry.
 729                          */
 730                         return ADD_TO_MLQUEUE;
 731                 break;
 732         }
 733         /* success just means we do not care what scsi-ml does */
 734         return SCSI_RETURN_NOT_HANDLED;
 735 }
 736
 737 static int rdac_bus_attach(struct scsi_device *sdev)
 738 {
 739         struct rdac_dh_data *h;
 740         int err;
 741         char array_name[ARRAY_LABEL_LEN];
 742         char array_id[UNIQUE_ID_LEN];
 743
 744         h = kzalloc(sizeof(*h) , GFP_KERNEL);
 745         if (!h)
 746                 return SCSI_DH_NOMEM;
 747         h->lun = UNINITIALIZED_LUN;
 748         h->state = RDAC_STATE_ACTIVE;
 749
 750         err = get_lun_info(sdev, h, array_name, array_id);
 751         if (err != SCSI_DH_OK)
 752                 goto failed;
 753
 754         err = initialize_controller(sdev, h, array_name, array_id);
 755         if (err != SCSI_DH_OK)
 756                 goto failed;
 757
 758         err = check_ownership(sdev, h);
 759         if (err != SCSI_DH_OK)
 760                 goto clean_ctlr;
 761
 762         err = set_mode_select(sdev, h);
 763         if (err != SCSI_DH_OK)
 764                 goto clean_ctlr;
 765
 766         sdev_printk(KERN_NOTICE, sdev,
 767                     "%s: LUN %d (%s) (%s)\n",
 768                     RDAC_NAME, h->lun, mode[(int)h->mode],
 769                     lun_state[(int)h->lun_state]);
 770
 771         sdev->handler_data = h;
 772         return SCSI_DH_OK;
 773
 774 clean_ctlr:
 775         spin_lock(&list_lock);
 776         kref_put(&h->ctlr->kref, release_controller);
 777         spin_unlock(&list_lock);
 778
 779 failed:
 780         kfree(h);
 781         return err;
 782 }
 783
 784 static void rdac_bus_detach( struct scsi_device *sdev )
 785 {
 786         struct rdac_dh_data *h = sdev->handler_data;
 787
 788         if (h->ctlr && h->ctlr->ms_queued)
 789                 flush_workqueue(kmpath_rdacd);
 790
 791         spin_lock(&list_lock);
 792         if (h->ctlr) {
 793                 list_del_rcu(&h->node);
 794                 kref_put(&h->ctlr->kref, release_controller);
 795         }
 796         spin_unlock(&list_lock);
 797         sdev->handler_data = NULL;
 798         synchronize_rcu();
 799         kfree(h);
 800 }
 801
 802 static struct scsi_device_handler rdac_dh = {
 803         .name = RDAC_NAME,
 804         .module = THIS_MODULE,
 805         .prep_fn = rdac_prep_fn,
 806         .check_sense = rdac_check_sense,
 807         .attach = rdac_bus_attach,
 808         .detach = rdac_bus_detach,
 809         .activate = rdac_activate,
 810 };
 811
 812 static int __init rdac_init(void)
 813 {
 814         int r;
 815
 816         r = scsi_register_device_handler(&rdac_dh);
 817         if (r != 0) {
 818                 printk(KERN_ERR "Failed to register scsi device handler.");
 819                 goto done;
 820         }
 821
 822         /*
 823          * Create workqueue to handle mode selects for rdac
 824          */
 825         kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
 826         if (!kmpath_rdacd) {
 827                 scsi_unregister_device_handler(&rdac_dh);
 828                 printk(KERN_ERR "kmpath_rdacd creation failed.\n");
 829
 830                 r = -EINVAL;
 831         }
 832 done:
 833         return r;
 834 }
 835
 836 static void __exit rdac_exit(void)
 837 {
 838         destroy_workqueue(kmpath_rdacd);
 839         scsi_unregister_device_handler(&rdac_dh);
 840 }
 841
 842 module_init(rdac_init);
 843 module_exit(rdac_exit);
 844
 845 MODULE_DESCRIPTION("Multipath LSI/Engenio/NetApp E-Series RDAC driver");
 846 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
 847 MODULE_VERSION("01.00.0000.0000");
 848 MODULE_LICENSE("GPL");