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 scsi_device *sdev = ctlr->ms_sdev;
 269         struct rdac_dh_data *h = sdev->handler_data;
 270         struct rdac_mode_common *common;
 271         unsigned data_size;
 272         struct rdac_queue_data *qdata;
 273         u8 *lun_table;
 274
 275         if (h->ctlr->use_ms10) {
 276                 struct rdac_pg_expanded *rdac_pg;
 277
 278                 data_size = sizeof(struct rdac_pg_expanded);
 279                 rdac_pg = &h->ctlr->mode_select.expanded;
 280                 memset(rdac_pg, 0, data_size);
 281                 common = &rdac_pg->common;
 282                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
 283                 rdac_pg->subpage_code = 0x1;
 284                 rdac_pg->page_len[0] = 0x01;
 285                 rdac_pg->page_len[1] = 0x28;
 286                 lun_table = rdac_pg->lun_table;
 287         } else {
 288                 struct rdac_pg_legacy *rdac_pg;
 289
 290                 data_size = sizeof(struct rdac_pg_legacy);
 291                 rdac_pg = &h->ctlr->mode_select.legacy;
 292                 memset(rdac_pg, 0, data_size);
 293                 common = &rdac_pg->common;
 294                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
 295                 rdac_pg->page_len = 0x68;
 296                 lun_table = rdac_pg->lun_table;
 297         }
 298         common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
 299         common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
 300         common->rdac_options = RDAC_FORCED_QUIESENCE;
 301
 302         list_for_each_entry(qdata, list, entry) {
 303                 lun_table[qdata->h->lun] = 0x81;
 304         }
 305
 306         /* Prepare the command. */
 307         if (h->ctlr->use_ms10) {
 308                 cdb[0] = MODE_SELECT_10;
 309                 cdb[7] = data_size >> 8;
 310                 cdb[8] = data_size & 0xff;
 311         } else {
 312                 cdb[0] = MODE_SELECT;
 313                 cdb[4] = data_size;
 314         }
 315
 316         return data_size;
 317 }
 318
 319 static void release_controller(struct kref *kref)
 320 {
 321         struct rdac_controller *ctlr;
 322         ctlr = container_of(kref, struct rdac_controller, kref);
 323
 324         list_del(&ctlr->node);
 325         kfree(ctlr);
 326 }
 327
 328 static struct rdac_controller *get_controller(int index, char *array_name,
 329                         u8 *array_id, struct scsi_device *sdev)
 330 {
 331         struct rdac_controller *ctlr, *tmp;
 332
 333         list_for_each_entry(tmp, &ctlr_list, node) {
 334                 if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
 335                           (tmp->index == index) &&
 336                           (tmp->host == sdev->host)) {
 337                         kref_get(&tmp->kref);
 338                         return tmp;
 339                 }
 340         }
 341         ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
 342         if (!ctlr)
 343                 return NULL;
 344
 345         /* initialize fields of controller */
 346         memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
 347         ctlr->index = index;
 348         ctlr->host = sdev->host;
 349         memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
 350
 351         kref_init(&ctlr->kref);
 352         ctlr->use_ms10 = -1;
 353         ctlr->ms_queued = 0;
 354         ctlr->ms_sdev = NULL;
 355         spin_lock_init(&ctlr->ms_lock);
 356         INIT_WORK(&ctlr->ms_work, send_mode_select);
 357         INIT_LIST_HEAD(&ctlr->ms_head);
 358         list_add(&ctlr->node, &ctlr_list);
 359         INIT_LIST_HEAD(&ctlr->dh_list);
 360
 361         return ctlr;
 362 }
 363
 364 static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
 365                         char *array_name, u8 *array_id)
 366 {
 367         int err = SCSI_DH_IO, i;
 368         struct c8_inquiry *inqp = &h->inq.c8;
 369
 370         if (!scsi_get_vpd_page(sdev, 0xC8, (unsigned char *)inqp,
 371                                sizeof(struct c8_inquiry))) {
 372                 if (inqp->page_code != 0xc8)
 373                         return SCSI_DH_NOSYS;
 374                 if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
 375                     inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
 376                         return SCSI_DH_NOSYS;
 377                 h->lun = inqp->lun[7]; /* Uses only the last byte */
 378
 379                 for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
 380                         *(array_name+i) = inqp->array_user_label[(2*i)+1];
 381
 382                 *(array_name+ARRAY_LABEL_LEN-1) = '\0';
 383                 memset(array_id, 0, UNIQUE_ID_LEN);
 384                 memcpy(array_id, inqp->array_unique_id, inqp->array_uniq_id_len);
 385                 err = SCSI_DH_OK;
 386         }
 387         return err;
 388 }
 389
 390 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
 391 {
 392         int err = SCSI_DH_IO, access_state;
 393         struct rdac_dh_data *tmp;
 394         struct c9_inquiry *inqp = &h->inq.c9;
 395
 396         h->state = RDAC_STATE_ACTIVE;
 397         if (!scsi_get_vpd_page(sdev, 0xC9, (unsigned char *)inqp,
 398                                sizeof(struct c9_inquiry))) {
 399                 /* detect the operating mode */
 400                 if ((inqp->avte_cvp >> 5) & 0x1)
 401                         h->mode = RDAC_MODE_IOSHIP; /* LUN in IOSHIP mode */
 402                 else if (inqp->avte_cvp >> 7)
 403                         h->mode = RDAC_MODE_AVT; /* LUN in AVT mode */
 404                 else
 405                         h->mode = RDAC_MODE; /* LUN in RDAC mode */
 406
 407                 /* Update ownership */
 408                 if (inqp->avte_cvp & 0x1) {
 409                         h->lun_state = RDAC_LUN_OWNED;
 410                         access_state = SCSI_ACCESS_STATE_OPTIMAL;
 411                 } else {
 412                         h->lun_state = RDAC_LUN_UNOWNED;
 413                         if (h->mode == RDAC_MODE) {
 414                                 h->state = RDAC_STATE_PASSIVE;
 415                                 access_state = SCSI_ACCESS_STATE_STANDBY;
 416                         } else
 417                                 access_state = SCSI_ACCESS_STATE_ACTIVE;
 418                 }
 419
 420                 /* Update path prio*/
 421                 if (inqp->path_prio & 0x1) {
 422                         h->preferred = RDAC_PREFERRED;
 423                         access_state |= SCSI_ACCESS_STATE_PREFERRED;
 424                 } else
 425                         h->preferred = RDAC_NON_PREFERRED;
 426                 rcu_read_lock();
 427                 list_for_each_entry_rcu(tmp, &h->ctlr->dh_list, node) {
 428                         /* h->sdev should always be valid */
 429                         BUG_ON(!tmp->sdev);
 430                         tmp->sdev->access_state = access_state;
 431                 }
 432                 rcu_read_unlock();
 433                 err = SCSI_DH_OK;
 434         }
 435
 436         return err;
 437 }
 438
 439 static int initialize_controller(struct scsi_device *sdev,
 440                 struct rdac_dh_data *h, char *array_name, u8 *array_id)
 441 {
 442         int err = SCSI_DH_IO, index;
 443         struct c4_inquiry *inqp = &h->inq.c4;
 444
 445         if (!scsi_get_vpd_page(sdev, 0xC4, (unsigned char *)inqp,
 446                                sizeof(struct c4_inquiry))) {
 447                 /* get the controller index */
 448                 if (inqp->slot_id[1] == 0x31)
 449                         index = 0;
 450                 else
 451                         index = 1;
 452
 453                 spin_lock(&list_lock);
 454                 h->ctlr = get_controller(index, array_name, array_id, sdev);
 455                 if (!h->ctlr)
 456                         err = SCSI_DH_RES_TEMP_UNAVAIL;
 457                 else {
 458                         list_add_rcu(&h->node, &h->ctlr->dh_list);
 459                         h->sdev = sdev;
 460                 }
 461                 spin_unlock(&list_lock);
 462                 err = SCSI_DH_OK;
 463         }
 464         return err;
 465 }
 466
 467 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
 468 {
 469         int err = SCSI_DH_IO;
 470         struct c2_inquiry *inqp = &h->inq.c2;
 471
 472         if (!scsi_get_vpd_page(sdev, 0xC2, (unsigned char *)inqp,
 473                                sizeof(struct c2_inquiry))) {
 474                 /*
 475                  * If more than MODE6_MAX_LUN luns are supported, use
 476                  * mode select 10
 477                  */
 478                 if (inqp->max_lun_supported >= MODE6_MAX_LUN)
 479                         h->ctlr->use_ms10 = 1;
 480                 else
 481                         h->ctlr->use_ms10 = 0;
 482                 err = SCSI_DH_OK;
 483         }
 484         return err;
 485 }
 486
 487 static int mode_select_handle_sense(struct scsi_device *sdev,
 488                                     struct scsi_sense_hdr *sense_hdr)
 489 {
 490         int err = SCSI_DH_IO;
 491         struct rdac_dh_data *h = sdev->handler_data;
 492
 493         if (!scsi_sense_valid(sense_hdr))
 494                 goto done;
 495
 496         switch (sense_hdr->sense_key) {
 497         case NO_SENSE:
 498         case ABORTED_COMMAND:
 499         case UNIT_ATTENTION:
 500                 err = SCSI_DH_RETRY;
 501                 break;
 502         case NOT_READY:
 503                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
 504                         /* LUN Not Ready and is in the Process of Becoming
 505                          * Ready
 506                          */
 507                         err = SCSI_DH_RETRY;
 508                 break;
 509         case ILLEGAL_REQUEST:
 510                 if (sense_hdr->asc == 0x91 && sense_hdr->ascq == 0x36)
 511                         /*
 512                          * Command Lock contention
 513                          */
 514                         err = SCSI_DH_IMM_RETRY;
 515                 break;
 516         default:
 517                 break;
 518         }
 519
 520         RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 521                 "MODE_SELECT returned with sense %02x/%02x/%02x",
 522                 (char *) h->ctlr->array_name, h->ctlr->index,
 523                 sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 524
 525 done:
 526         return err;
 527 }
 528
 529 static void send_mode_select(struct work_struct *work)
 530 {
 531         struct rdac_controller *ctlr =
 532                 container_of(work, struct rdac_controller, ms_work);
 533         struct scsi_device *sdev = ctlr->ms_sdev;
 534         struct rdac_dh_data *h = sdev->handler_data;
 535         int err = SCSI_DH_OK, retry_cnt = RDAC_RETRY_COUNT;
 536         struct rdac_queue_data *tmp, *qdata;
 537         LIST_HEAD(list);
 538         unsigned char cdb[COMMAND_SIZE(MODE_SELECT_10)];
 539         struct scsi_sense_hdr sshdr;
 540         unsigned int data_size;
 541         u64 req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 542                 REQ_FAILFAST_DRIVER;
 543
 544         spin_lock(&ctlr->ms_lock);
 545         list_splice_init(&ctlr->ms_head, &list);
 546         ctlr->ms_queued = 0;
 547         ctlr->ms_sdev = NULL;
 548         spin_unlock(&ctlr->ms_lock);
 549
 550  retry:
 551         data_size = rdac_failover_get(ctlr, &list, cdb);
 552
 553         RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 554                 "%s MODE_SELECT command",
 555                 (char *) h->ctlr->array_name, h->ctlr->index,
 556                 (retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
 557
 558         if (scsi_execute_req_flags(sdev, cdb, DMA_TO_DEVICE,
 559                                    &h->ctlr->mode_select, data_size, &sshdr,
 560                                    RDAC_TIMEOUT * HZ,
 561                                    RDAC_RETRIES, NULL, req_flags, 0)) {
 562                 err = mode_select_handle_sense(sdev, &sshdr);
 563                 if (err == SCSI_DH_RETRY && retry_cnt--)
 564                         goto retry;
 565                 if (err == SCSI_DH_IMM_RETRY)
 566                         goto retry;
 567         }
 568         if (err == SCSI_DH_OK) {
 569                 h->state = RDAC_STATE_ACTIVE;
 570                 RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 571                                 "MODE_SELECT completed",
 572                                 (char *) h->ctlr->array_name, h->ctlr->index);
 573         }
 574
 575         list_for_each_entry_safe(qdata, tmp, &list, entry) {
 576                 list_del(&qdata->entry);
 577                 if (err == SCSI_DH_OK)
 578                         qdata->h->state = RDAC_STATE_ACTIVE;
 579                 if (qdata->callback_fn)
 580                         qdata->callback_fn(qdata->callback_data, err);
 581                 kfree(qdata);
 582         }
 583         return;
 584 }
 585
 586 static int queue_mode_select(struct scsi_device *sdev,
 587                                 activate_complete fn, void *data)
 588 {
 589         struct rdac_queue_data *qdata;
 590         struct rdac_controller *ctlr;
 591
 592         qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
 593         if (!qdata)
 594                 return SCSI_DH_RETRY;
 595
 596         qdata->h = sdev->handler_data;
 597         qdata->callback_fn = fn;
 598         qdata->callback_data = data;
 599
 600         ctlr = qdata->h->ctlr;
 601         spin_lock(&ctlr->ms_lock);
 602         list_add_tail(&qdata->entry, &ctlr->ms_head);
 603         if (!ctlr->ms_queued) {
 604                 ctlr->ms_queued = 1;
 605                 ctlr->ms_sdev = sdev;
 606                 queue_work(kmpath_rdacd, &ctlr->ms_work);
 607         }
 608         spin_unlock(&ctlr->ms_lock);
 609         return SCSI_DH_OK;
 610 }
 611
 612 static int rdac_activate(struct scsi_device *sdev,
 613                         activate_complete fn, void *data)
 614 {
 615         struct rdac_dh_data *h = sdev->handler_data;
 616         int err = SCSI_DH_OK;
 617         int act = 0;
 618
 619         err = check_ownership(sdev, h);
 620         if (err != SCSI_DH_OK)
 621                 goto done;
 622
 623         switch (h->mode) {
 624         case RDAC_MODE:
 625                 if (h->lun_state == RDAC_LUN_UNOWNED)
 626                         act = 1;
 627                 break;
 628         case RDAC_MODE_IOSHIP:
 629                 if ((h->lun_state == RDAC_LUN_UNOWNED) &&
 630                     (h->preferred == RDAC_PREFERRED))
 631                         act = 1;
 632                 break;
 633         default:
 634                 break;
 635         }
 636
 637         if (act) {
 638                 err = queue_mode_select(sdev, fn, data);
 639                 if (err == SCSI_DH_OK)
 640                         return 0;
 641         }
 642 done:
 643         if (fn)
 644                 fn(data, err);
 645         return 0;
 646 }
 647
 648 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
 649 {
 650         struct rdac_dh_data *h = sdev->handler_data;
 651         int ret = BLKPREP_OK;
 652
 653         if (h->state != RDAC_STATE_ACTIVE) {
 654                 ret = BLKPREP_KILL;
 655                 req->rq_flags |= RQF_QUIET;
 656         }
 657         return ret;
 658
 659 }
 660
 661 static int rdac_check_sense(struct scsi_device *sdev,
 662                                 struct scsi_sense_hdr *sense_hdr)
 663 {
 664         struct rdac_dh_data *h = sdev->handler_data;
 665
 666         RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
 667                         "I/O returned with sense %02x/%02x/%02x",
 668                         (char *) h->ctlr->array_name, h->ctlr->index,
 669                         sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 670
 671         switch (sense_hdr->sense_key) {
 672         case NOT_READY:
 673                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
 674                         /* LUN Not Ready - Logical Unit Not Ready and is in
 675                         * the process of becoming ready
 676                         * Just retry.
 677                         */
 678                         return ADD_TO_MLQUEUE;
 679                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
 680                         /* LUN Not Ready - Storage firmware incompatible
 681                          * Manual code synchonisation required.
 682                          *
 683                          * Nothing we can do here. Try to bypass the path.
 684                          */
 685                         return SUCCESS;
 686                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
 687                         /* LUN Not Ready - Quiescense in progress
 688                          *
 689                          * Just retry and wait.
 690                          */
 691                         return ADD_TO_MLQUEUE;
 692                 if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
 693                         /* LUN Not Ready - Quiescense in progress
 694                          * or has been achieved
 695                          * Just retry.
 696                          */
 697                         return ADD_TO_MLQUEUE;
 698                 break;
 699         case ILLEGAL_REQUEST:
 700                 if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
 701                         /* Invalid Request - Current Logical Unit Ownership.
 702                          * Controller is not the current owner of the LUN,
 703                          * Fail the path, so that the other path be used.
 704                          */
 705                         h->state = RDAC_STATE_PASSIVE;
 706                         return SUCCESS;
 707                 }
 708                 break;
 709         case UNIT_ATTENTION:
 710                 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 711                         /*
 712                          * Power On, Reset, or Bus Device Reset, just retry.
 713                          */
 714                         return ADD_TO_MLQUEUE;
 715                 if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
 716                         /*
 717                          * Quiescence in progress , just retry.
 718                          */
 719                         return ADD_TO_MLQUEUE;
 720                 break;
 721         }
 722         /* success just means we do not care what scsi-ml does */
 723         return SCSI_RETURN_NOT_HANDLED;
 724 }
 725
 726 static int rdac_bus_attach(struct scsi_device *sdev)
 727 {
 728         struct rdac_dh_data *h;
 729         int err;
 730         char array_name[ARRAY_LABEL_LEN];
 731         char array_id[UNIQUE_ID_LEN];
 732
 733         h = kzalloc(sizeof(*h) , GFP_KERNEL);
 734         if (!h)
 735                 return -ENOMEM;
 736         h->lun = UNINITIALIZED_LUN;
 737         h->state = RDAC_STATE_ACTIVE;
 738
 739         err = get_lun_info(sdev, h, array_name, array_id);
 740         if (err != SCSI_DH_OK)
 741                 goto failed;
 742
 743         err = initialize_controller(sdev, h, array_name, array_id);
 744         if (err != SCSI_DH_OK)
 745                 goto failed;
 746
 747         err = check_ownership(sdev, h);
 748         if (err != SCSI_DH_OK)
 749                 goto clean_ctlr;
 750
 751         err = set_mode_select(sdev, h);
 752         if (err != SCSI_DH_OK)
 753                 goto clean_ctlr;
 754
 755         sdev_printk(KERN_NOTICE, sdev,
 756                     "%s: LUN %d (%s) (%s)\n",
 757                     RDAC_NAME, h->lun, mode[(int)h->mode],
 758                     lun_state[(int)h->lun_state]);
 759
 760         sdev->handler_data = h;
 761         return 0;
 762
 763 clean_ctlr:
 764         spin_lock(&list_lock);
 765         kref_put(&h->ctlr->kref, release_controller);
 766         spin_unlock(&list_lock);
 767
 768 failed:
 769         kfree(h);
 770         return -EINVAL;
 771 }
 772
 773 static void rdac_bus_detach( struct scsi_device *sdev )
 774 {
 775         struct rdac_dh_data *h = sdev->handler_data;
 776
 777         if (h->ctlr && h->ctlr->ms_queued)
 778                 flush_workqueue(kmpath_rdacd);
 779
 780         spin_lock(&list_lock);
 781         if (h->ctlr) {
 782                 list_del_rcu(&h->node);
 783                 h->sdev = NULL;
 784                 kref_put(&h->ctlr->kref, release_controller);
 785         }
 786         spin_unlock(&list_lock);
 787         sdev->handler_data = NULL;
 788         kfree(h);
 789 }
 790
 791 static struct scsi_device_handler rdac_dh = {
 792         .name = RDAC_NAME,
 793         .module = THIS_MODULE,
 794         .prep_fn = rdac_prep_fn,
 795         .check_sense = rdac_check_sense,
 796         .attach = rdac_bus_attach,
 797         .detach = rdac_bus_detach,
 798         .activate = rdac_activate,
 799 };
 800
 801 static int __init rdac_init(void)
 802 {
 803         int r;
 804
 805         r = scsi_register_device_handler(&rdac_dh);
 806         if (r != 0) {
 807                 printk(KERN_ERR "Failed to register scsi device handler.");
 808                 goto done;
 809         }
 810
 811         /*
 812          * Create workqueue to handle mode selects for rdac
 813          */
 814         kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
 815         if (!kmpath_rdacd) {
 816                 scsi_unregister_device_handler(&rdac_dh);
 817                 printk(KERN_ERR "kmpath_rdacd creation failed.\n");
 818
 819                 r = -EINVAL;
 820         }
 821 done:
 822         return r;
 823 }
 824
 825 static void __exit rdac_exit(void)
 826 {
 827         destroy_workqueue(kmpath_rdacd);
 828         scsi_unregister_device_handler(&rdac_dh);
 829 }
 830
 831 module_init(rdac_init);
 832 module_exit(rdac_exit);
 833
 834 MODULE_DESCRIPTION("Multipath LSI/Engenio/NetApp E-Series RDAC driver");
 835 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
 836 MODULE_VERSION("01.00.0000.0000");
 837 MODULE_LICENSE("GPL");