drivers/scsi/device_handler/scsi_dh_rdac.c

   1 /*
   2  * Engenio/LSI 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
  26 #define RDAC_NAME "rdac"
  27 #define RDAC_RETRY_COUNT 5
  28
  29 /*
  30  * LSI mode page stuff
  31  *
  32  * These struct definitions and the forming of the
  33  * mode page were taken from the LSI RDAC 2.4 GPL'd
  34  * driver, and then converted to Linux conventions.
  35  */
  36 #define RDAC_QUIESCENCE_TIME 20;
  37 /*
  38  * Page Codes
  39  */
  40 #define RDAC_PAGE_CODE_REDUNDANT_CONTROLLER 0x2c
  41
  42 /*
  43  * Controller modes definitions
  44  */
  45 #define RDAC_MODE_TRANSFER_SPECIFIED_LUNS       0x02
  46
  47 /*
  48  * RDAC Options field
  49  */
  50 #define RDAC_FORCED_QUIESENCE 0x02
  51
  52 #define RDAC_TIMEOUT    (60 * HZ)
  53 #define RDAC_RETRIES    3
  54
  55 struct rdac_mode_6_hdr {
  56         u8      data_len;
  57         u8      medium_type;
  58         u8      device_params;
  59         u8      block_desc_len;
  60 };
  61
  62 struct rdac_mode_10_hdr {
  63         u16     data_len;
  64         u8      medium_type;
  65         u8      device_params;
  66         u16     reserved;
  67         u16     block_desc_len;
  68 };
  69
  70 struct rdac_mode_common {
  71         u8      controller_serial[16];
  72         u8      alt_controller_serial[16];
  73         u8      rdac_mode[2];
  74         u8      alt_rdac_mode[2];
  75         u8      quiescence_timeout;
  76         u8      rdac_options;
  77 };
  78
  79 struct rdac_pg_legacy {
  80         struct rdac_mode_6_hdr hdr;
  81         u8      page_code;
  82         u8      page_len;
  83         struct rdac_mode_common common;
  84 #define MODE6_MAX_LUN   32
  85         u8      lun_table[MODE6_MAX_LUN];
  86         u8      reserved2[32];
  87         u8      reserved3;
  88         u8      reserved4;
  89 };
  90
  91 struct rdac_pg_expanded {
  92         struct rdac_mode_10_hdr hdr;
  93         u8      page_code;
  94         u8      subpage_code;
  95         u8      page_len[2];
  96         struct rdac_mode_common common;
  97         u8      lun_table[256];
  98         u8      reserved3;
  99         u8      reserved4;
 100 };
 101
 102 struct c9_inquiry {
 103         u8      peripheral_info;
 104         u8      page_code;      /* 0xC9 */
 105         u8      reserved1;
 106         u8      page_len;
 107         u8      page_id[4];     /* "vace" */
 108         u8      avte_cvp;
 109         u8      path_prio;
 110         u8      reserved2[38];
 111 };
 112
 113 #define SUBSYS_ID_LEN   16
 114 #define SLOT_ID_LEN     2
 115
 116 struct c4_inquiry {
 117         u8      peripheral_info;
 118         u8      page_code;      /* 0xC4 */
 119         u8      reserved1;
 120         u8      page_len;
 121         u8      page_id[4];     /* "subs" */
 122         u8      subsys_id[SUBSYS_ID_LEN];
 123         u8      revision[4];
 124         u8      slot_id[SLOT_ID_LEN];
 125         u8      reserved[2];
 126 };
 127
 128 struct rdac_controller {
 129         u8                      subsys_id[SUBSYS_ID_LEN];
 130         u8                      slot_id[SLOT_ID_LEN];
 131         int                     use_ms10;
 132         struct kref             kref;
 133         struct list_head        node; /* list of all controllers */
 134         union                   {
 135                 struct rdac_pg_legacy legacy;
 136                 struct rdac_pg_expanded expanded;
 137         } mode_select;
 138 };
 139 struct c8_inquiry {
 140         u8      peripheral_info;
 141         u8      page_code; /* 0xC8 */
 142         u8      reserved1;
 143         u8      page_len;
 144         u8      page_id[4]; /* "edid" */
 145         u8      reserved2[3];
 146         u8      vol_uniq_id_len;
 147         u8      vol_uniq_id[16];
 148         u8      vol_user_label_len;
 149         u8      vol_user_label[60];
 150         u8      array_uniq_id_len;
 151         u8      array_unique_id[16];
 152         u8      array_user_label_len;
 153         u8      array_user_label[60];
 154         u8      lun[8];
 155 };
 156
 157 struct c2_inquiry {
 158         u8      peripheral_info;
 159         u8      page_code;      /* 0xC2 */
 160         u8      reserved1;
 161         u8      page_len;
 162         u8      page_id[4];     /* "swr4" */
 163         u8      sw_version[3];
 164         u8      sw_date[3];
 165         u8      features_enabled;
 166         u8      max_lun_supported;
 167         u8      partitions[239]; /* Total allocation length should be 0xFF */
 168 };
 169
 170 struct rdac_dh_data {
 171         struct rdac_controller  *ctlr;
 172 #define UNINITIALIZED_LUN       (1 << 8)
 173         unsigned                lun;
 174 #define RDAC_STATE_ACTIVE       0
 175 #define RDAC_STATE_PASSIVE      1
 176         unsigned char           state;
 177
 178 #define RDAC_LUN_UNOWNED        0
 179 #define RDAC_LUN_OWNED          1
 180 #define RDAC_LUN_AVT            2
 181         char                    lun_state;
 182         unsigned char           sense[SCSI_SENSE_BUFFERSIZE];
 183         union                   {
 184                 struct c2_inquiry c2;
 185                 struct c4_inquiry c4;
 186                 struct c8_inquiry c8;
 187                 struct c9_inquiry c9;
 188         } inq;
 189 };
 190
 191 static const char *lun_state[] =
 192 {
 193         "unowned",
 194         "owned",
 195         "owned (AVT mode)",
 196 };
 197
 198 static LIST_HEAD(ctlr_list);
 199 static DEFINE_SPINLOCK(list_lock);
 200
 201 static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev)
 202 {
 203         struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
 204         BUG_ON(scsi_dh_data == NULL);
 205         return ((struct rdac_dh_data *) scsi_dh_data->buf);
 206 }
 207
 208 static struct request *get_rdac_req(struct scsi_device *sdev,
 209                         void *buffer, unsigned buflen, int rw)
 210 {
 211         struct request *rq;
 212         struct request_queue *q = sdev->request_queue;
 213
 214         rq = blk_get_request(q, rw, GFP_NOIO);
 215
 216         if (!rq) {
 217                 sdev_printk(KERN_INFO, sdev,
 218                                 "get_rdac_req: blk_get_request failed.\n");
 219                 return NULL;
 220         }
 221
 222         if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
 223                 blk_put_request(rq);
 224                 sdev_printk(KERN_INFO, sdev,
 225                                 "get_rdac_req: blk_rq_map_kern failed.\n");
 226                 return NULL;
 227         }
 228
 229         rq->cmd_type = REQ_TYPE_BLOCK_PC;
 230         rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 231                          REQ_FAILFAST_DRIVER;
 232         rq->retries = RDAC_RETRIES;
 233         rq->timeout = RDAC_TIMEOUT;
 234
 235         return rq;
 236 }
 237
 238 static struct request *rdac_failover_get(struct scsi_device *sdev,
 239                                          struct rdac_dh_data *h)
 240 {
 241         struct request *rq;
 242         struct rdac_mode_common *common;
 243         unsigned data_size;
 244
 245         if (h->ctlr->use_ms10) {
 246                 struct rdac_pg_expanded *rdac_pg;
 247
 248                 data_size = sizeof(struct rdac_pg_expanded);
 249                 rdac_pg = &h->ctlr->mode_select.expanded;
 250                 memset(rdac_pg, 0, data_size);
 251                 common = &rdac_pg->common;
 252                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
 253                 rdac_pg->subpage_code = 0x1;
 254                 rdac_pg->page_len[0] = 0x01;
 255                 rdac_pg->page_len[1] = 0x28;
 256                 rdac_pg->lun_table[h->lun] = 0x81;
 257         } else {
 258                 struct rdac_pg_legacy *rdac_pg;
 259
 260                 data_size = sizeof(struct rdac_pg_legacy);
 261                 rdac_pg = &h->ctlr->mode_select.legacy;
 262                 memset(rdac_pg, 0, data_size);
 263                 common = &rdac_pg->common;
 264                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
 265                 rdac_pg->page_len = 0x68;
 266                 rdac_pg->lun_table[h->lun] = 0x81;
 267         }
 268         common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
 269         common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
 270         common->rdac_options = RDAC_FORCED_QUIESENCE;
 271
 272         /* get request for block layer packet command */
 273         rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE);
 274         if (!rq)
 275                 return NULL;
 276
 277         /* Prepare the command. */
 278         if (h->ctlr->use_ms10) {
 279                 rq->cmd[0] = MODE_SELECT_10;
 280                 rq->cmd[7] = data_size >> 8;
 281                 rq->cmd[8] = data_size & 0xff;
 282         } else {
 283                 rq->cmd[0] = MODE_SELECT;
 284                 rq->cmd[4] = data_size;
 285         }
 286         rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
 287
 288         rq->sense = h->sense;
 289         memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
 290         rq->sense_len = 0;
 291
 292         return rq;
 293 }
 294
 295 static void release_controller(struct kref *kref)
 296 {
 297         struct rdac_controller *ctlr;
 298         ctlr = container_of(kref, struct rdac_controller, kref);
 299
 300         spin_lock(&list_lock);
 301         list_del(&ctlr->node);
 302         spin_unlock(&list_lock);
 303         kfree(ctlr);
 304 }
 305
 306 static struct rdac_controller *get_controller(u8 *subsys_id, u8 *slot_id)
 307 {
 308         struct rdac_controller *ctlr, *tmp;
 309
 310         spin_lock(&list_lock);
 311
 312         list_for_each_entry(tmp, &ctlr_list, node) {
 313                 if ((memcmp(tmp->subsys_id, subsys_id, SUBSYS_ID_LEN) == 0) &&
 314                           (memcmp(tmp->slot_id, slot_id, SLOT_ID_LEN) == 0)) {
 315                         kref_get(&tmp->kref);
 316                         spin_unlock(&list_lock);
 317                         return tmp;
 318                 }
 319         }
 320         ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
 321         if (!ctlr)
 322                 goto done;
 323
 324         /* initialize fields of controller */
 325         memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN);
 326         memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN);
 327         kref_init(&ctlr->kref);
 328         ctlr->use_ms10 = -1;
 329         list_add(&ctlr->node, &ctlr_list);
 330 done:
 331         spin_unlock(&list_lock);
 332         return ctlr;
 333 }
 334
 335 static int submit_inquiry(struct scsi_device *sdev, int page_code,
 336                           unsigned int len, struct rdac_dh_data *h)
 337 {
 338         struct request *rq;
 339         struct request_queue *q = sdev->request_queue;
 340         int err = SCSI_DH_RES_TEMP_UNAVAIL;
 341
 342         rq = get_rdac_req(sdev, &h->inq, len, READ);
 343         if (!rq)
 344                 goto done;
 345
 346         /* Prepare the command. */
 347         rq->cmd[0] = INQUIRY;
 348         rq->cmd[1] = 1;
 349         rq->cmd[2] = page_code;
 350         rq->cmd[4] = len;
 351         rq->cmd_len = COMMAND_SIZE(INQUIRY);
 352
 353         rq->sense = h->sense;
 354         memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
 355         rq->sense_len = 0;
 356
 357         err = blk_execute_rq(q, NULL, rq, 1);
 358         if (err == -EIO)
 359                 err = SCSI_DH_IO;
 360
 361         blk_put_request(rq);
 362 done:
 363         return err;
 364 }
 365
 366 static int get_lun(struct scsi_device *sdev, struct rdac_dh_data *h)
 367 {
 368         int err;
 369         struct c8_inquiry *inqp;
 370
 371         err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h);
 372         if (err == SCSI_DH_OK) {
 373                 inqp = &h->inq.c8;
 374                 if (inqp->page_code != 0xc8)
 375                         return SCSI_DH_NOSYS;
 376                 if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
 377                     inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
 378                         return SCSI_DH_NOSYS;
 379                 h->lun = inqp->lun[7]; /* Uses only the last byte */
 380         }
 381         return err;
 382 }
 383
 384 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
 385 {
 386         int err;
 387         struct c9_inquiry *inqp;
 388
 389         h->lun_state = RDAC_LUN_UNOWNED;
 390         h->state = RDAC_STATE_ACTIVE;
 391         err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h);
 392         if (err == SCSI_DH_OK) {
 393                 inqp = &h->inq.c9;
 394                 if ((inqp->avte_cvp >> 7) == 0x1) {
 395                         /* LUN in AVT mode */
 396                         sdev_printk(KERN_NOTICE, sdev,
 397                                     "%s: AVT mode detected\n",
 398                                     RDAC_NAME);
 399                         h->lun_state = RDAC_LUN_AVT;
 400                 } else if ((inqp->avte_cvp & 0x1) != 0) {
 401                         /* LUN was owned by the controller */
 402                         h->lun_state = RDAC_LUN_OWNED;
 403                 }
 404         }
 405
 406         if (h->lun_state == RDAC_LUN_UNOWNED)
 407                 h->state = RDAC_STATE_PASSIVE;
 408
 409         return err;
 410 }
 411
 412 static int initialize_controller(struct scsi_device *sdev,
 413                                  struct rdac_dh_data *h)
 414 {
 415         int err;
 416         struct c4_inquiry *inqp;
 417
 418         err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h);
 419         if (err == SCSI_DH_OK) {
 420                 inqp = &h->inq.c4;
 421                 h->ctlr = get_controller(inqp->subsys_id, inqp->slot_id);
 422                 if (!h->ctlr)
 423                         err = SCSI_DH_RES_TEMP_UNAVAIL;
 424         }
 425         return err;
 426 }
 427
 428 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
 429 {
 430         int err;
 431         struct c2_inquiry *inqp;
 432
 433         err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h);
 434         if (err == SCSI_DH_OK) {
 435                 inqp = &h->inq.c2;
 436                 /*
 437                  * If more than MODE6_MAX_LUN luns are supported, use
 438                  * mode select 10
 439                  */
 440                 if (inqp->max_lun_supported >= MODE6_MAX_LUN)
 441                         h->ctlr->use_ms10 = 1;
 442                 else
 443                         h->ctlr->use_ms10 = 0;
 444         }
 445         return err;
 446 }
 447
 448 static int mode_select_handle_sense(struct scsi_device *sdev,
 449                                     unsigned char *sensebuf)
 450 {
 451         struct scsi_sense_hdr sense_hdr;
 452         int err = SCSI_DH_IO, ret;
 453
 454         ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr);
 455         if (!ret)
 456                 goto done;
 457
 458         err = SCSI_DH_OK;
 459
 460         switch (sense_hdr.sense_key) {
 461         case NO_SENSE:
 462         case ABORTED_COMMAND:
 463         case UNIT_ATTENTION:
 464                 err = SCSI_DH_RETRY;
 465                 break;
 466         case NOT_READY:
 467                 if (sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x01)
 468                         /* LUN Not Ready and is in the Process of Becoming
 469                          * Ready
 470                          */
 471                         err = SCSI_DH_RETRY;
 472                 break;
 473         case ILLEGAL_REQUEST:
 474                 if (sense_hdr.asc == 0x91 && sense_hdr.ascq == 0x36)
 475                         /*
 476                          * Command Lock contention
 477                          */
 478                         err = SCSI_DH_RETRY;
 479                 break;
 480         default:
 481                 sdev_printk(KERN_INFO, sdev,
 482                             "MODE_SELECT failed with sense %02x/%02x/%02x.\n",
 483                             sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
 484         }
 485
 486 done:
 487         return err;
 488 }
 489
 490 static int send_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
 491 {
 492         struct request *rq;
 493         struct request_queue *q = sdev->request_queue;
 494         int err, retry_cnt = RDAC_RETRY_COUNT;
 495
 496 retry:
 497         err = SCSI_DH_RES_TEMP_UNAVAIL;
 498         rq = rdac_failover_get(sdev, h);
 499         if (!rq)
 500                 goto done;
 501
 502         sdev_printk(KERN_INFO, sdev, "%s MODE_SELECT command.\n",
 503                 (retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
 504
 505         err = blk_execute_rq(q, NULL, rq, 1);
 506         blk_put_request(rq);
 507         if (err != SCSI_DH_OK) {
 508                 err = mode_select_handle_sense(sdev, h->sense);
 509                 if (err == SCSI_DH_RETRY && retry_cnt--)
 510                         goto retry;
 511         }
 512         if (err == SCSI_DH_OK)
 513                 h->state = RDAC_STATE_ACTIVE;
 514
 515 done:
 516         return err;
 517 }
 518
 519 static int rdac_activate(struct scsi_device *sdev)
 520 {
 521         struct rdac_dh_data *h = get_rdac_data(sdev);
 522         int err = SCSI_DH_OK;
 523
 524         err = check_ownership(sdev, h);
 525         if (err != SCSI_DH_OK)
 526                 goto done;
 527
 528         if (!h->ctlr) {
 529                 err = initialize_controller(sdev, h);
 530                 if (err != SCSI_DH_OK)
 531                         goto done;
 532         }
 533
 534         if (h->ctlr->use_ms10 == -1) {
 535                 err = set_mode_select(sdev, h);
 536                 if (err != SCSI_DH_OK)
 537                         goto done;
 538         }
 539         if (h->lun_state == RDAC_LUN_UNOWNED)
 540                 err = send_mode_select(sdev, h);
 541 done:
 542         return err;
 543 }
 544
 545 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
 546 {
 547         struct rdac_dh_data *h = get_rdac_data(sdev);
 548         int ret = BLKPREP_OK;
 549
 550         if (h->state != RDAC_STATE_ACTIVE) {
 551                 ret = BLKPREP_KILL;
 552                 req->cmd_flags |= REQ_QUIET;
 553         }
 554         return ret;
 555
 556 }
 557
 558 static int rdac_check_sense(struct scsi_device *sdev,
 559                                 struct scsi_sense_hdr *sense_hdr)
 560 {
 561         struct rdac_dh_data *h = get_rdac_data(sdev);
 562         switch (sense_hdr->sense_key) {
 563         case NOT_READY:
 564                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
 565                         /* LUN Not Ready - Storage firmware incompatible
 566                          * Manual code synchonisation required.
 567                          *
 568                          * Nothing we can do here. Try to bypass the path.
 569                          */
 570                         return SUCCESS;
 571                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
 572                         /* LUN Not Ready - Quiescense in progress
 573                          *
 574                          * Just retry and wait.
 575                          */
 576                         return ADD_TO_MLQUEUE;
 577                 if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
 578                         /* LUN Not Ready - Quiescense in progress
 579                          * or has been achieved
 580                          * Just retry.
 581                          */
 582                         return ADD_TO_MLQUEUE;
 583                 break;
 584         case ILLEGAL_REQUEST:
 585                 if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
 586                         /* Invalid Request - Current Logical Unit Ownership.
 587                          * Controller is not the current owner of the LUN,
 588                          * Fail the path, so that the other path be used.
 589                          */
 590                         h->state = RDAC_STATE_PASSIVE;
 591                         return SUCCESS;
 592                 }
 593                 break;
 594         case UNIT_ATTENTION:
 595                 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 596                         /*
 597                          * Power On, Reset, or Bus Device Reset, just retry.
 598                          */
 599                         return ADD_TO_MLQUEUE;
 600                 if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
 601                         /*
 602                          * Quiescence in progress , just retry.
 603                          */
 604                         return ADD_TO_MLQUEUE;
 605                 break;
 606         }
 607         /* success just means we do not care what scsi-ml does */
 608         return SCSI_RETURN_NOT_HANDLED;
 609 }
 610
 611 static const struct scsi_dh_devlist rdac_dev_list[] = {
 612         {"IBM", "1722"},
 613         {"IBM", "1724"},
 614         {"IBM", "1726"},
 615         {"IBM", "1742"},
 616         {"IBM", "1814"},
 617         {"IBM", "1815"},
 618         {"IBM", "1818"},
 619         {"IBM", "3526"},
 620         {"SGI", "TP9400"},
 621         {"SGI", "TP9500"},
 622         {"SGI", "IS"},
 623         {"STK", "OPENstorage D280"},
 624         {"SUN", "CSM200_R"},
 625         {"SUN", "LCSM100_F"},
 626         {"DELL", "MD3000"},
 627         {"DELL", "MD3000i"},
 628         {"LSI", "INF-01-00"},
 629         {"ENGENIO", "INF-01-00"},
 630         {NULL, NULL},
 631 };
 632
 633 static int rdac_bus_attach(struct scsi_device *sdev);
 634 static void rdac_bus_detach(struct scsi_device *sdev);
 635
 636 static struct scsi_device_handler rdac_dh = {
 637         .name = RDAC_NAME,
 638         .module = THIS_MODULE,
 639         .devlist = rdac_dev_list,
 640         .prep_fn = rdac_prep_fn,
 641         .check_sense = rdac_check_sense,
 642         .attach = rdac_bus_attach,
 643         .detach = rdac_bus_detach,
 644         .activate = rdac_activate,
 645 };
 646
 647 static int rdac_bus_attach(struct scsi_device *sdev)
 648 {
 649         struct scsi_dh_data *scsi_dh_data;
 650         struct rdac_dh_data *h;
 651         unsigned long flags;
 652         int err;
 653
 654         scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
 655                                + sizeof(*h) , GFP_KERNEL);
 656         if (!scsi_dh_data) {
 657                 sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
 658                             RDAC_NAME);
 659                 return 0;
 660         }
 661
 662         scsi_dh_data->scsi_dh = &rdac_dh;
 663         h = (struct rdac_dh_data *) scsi_dh_data->buf;
 664         h->lun = UNINITIALIZED_LUN;
 665         h->state = RDAC_STATE_ACTIVE;
 666
 667         err = get_lun(sdev, h);
 668         if (err != SCSI_DH_OK)
 669                 goto failed;
 670
 671         err = check_ownership(sdev, h);
 672         if (err != SCSI_DH_OK)
 673                 goto failed;
 674
 675         if (!try_module_get(THIS_MODULE))
 676                 goto failed;
 677
 678         spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
 679         sdev->scsi_dh_data = scsi_dh_data;
 680         spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 681
 682         sdev_printk(KERN_NOTICE, sdev,
 683                     "%s: LUN %d (%s)\n",
 684                     RDAC_NAME, h->lun, lun_state[(int)h->lun_state]);
 685
 686         return 0;
 687
 688 failed:
 689         kfree(scsi_dh_data);
 690         sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
 691                     RDAC_NAME);
 692         return -EINVAL;
 693 }
 694
 695 static void rdac_bus_detach( struct scsi_device *sdev )
 696 {
 697         struct scsi_dh_data *scsi_dh_data;
 698         struct rdac_dh_data *h;
 699         unsigned long flags;
 700
 701         spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
 702         scsi_dh_data = sdev->scsi_dh_data;
 703         sdev->scsi_dh_data = NULL;
 704         spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 705
 706         h = (struct rdac_dh_data *) scsi_dh_data->buf;
 707         if (h->ctlr)
 708                 kref_put(&h->ctlr->kref, release_controller);
 709         kfree(scsi_dh_data);
 710         module_put(THIS_MODULE);
 711         sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME);
 712 }
 713
 714
 715
 716 static int __init rdac_init(void)
 717 {
 718         int r;
 719
 720         r = scsi_register_device_handler(&rdac_dh);
 721         if (r != 0)
 722                 printk(KERN_ERR "Failed to register scsi device handler.");
 723         return r;
 724 }
 725
 726 static void __exit rdac_exit(void)
 727 {
 728         scsi_unregister_device_handler(&rdac_dh);
 729 }
 730
 731 module_init(rdac_init);
 732 module_exit(rdac_exit);
 733
 734 MODULE_DESCRIPTION("Multipath LSI/Engenio RDAC driver");
 735 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
 736 MODULE_LICENSE("GPL");