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 };
 169
 170 struct c2_inquiry {
 171         u8      peripheral_info;
 172         u8      page_code;      /* 0xC2 */
 173         u8      reserved1;
 174         u8      page_len;
 175         u8      page_id[4];     /* "swr4" */
 176         u8      sw_version[3];
 177         u8      sw_date[3];
 178         u8      features_enabled;
 179         u8      max_lun_supported;
 180         u8      partitions[239]; /* Total allocation length should be 0xFF */
 181 };
 182
 183 struct rdac_dh_data {
 184         struct rdac_controller  *ctlr;
 185 #define UNINITIALIZED_LUN       (1 << 8)
 186         unsigned                lun;
 187
 188 #define RDAC_MODE               0
 189 #define RDAC_MODE_AVT           1
 190 #define RDAC_MODE_IOSHIP        2
 191         unsigned char           mode;
 192
 193 #define RDAC_STATE_ACTIVE       0
 194 #define RDAC_STATE_PASSIVE      1
 195         unsigned char           state;
 196
 197 #define RDAC_LUN_UNOWNED        0
 198 #define RDAC_LUN_OWNED          1
 199         char                    lun_state;
 200
 201 #define RDAC_PREFERRED          0
 202 #define RDAC_NON_PREFERRED      1
 203         char                    preferred;
 204
 205         unsigned char           sense[SCSI_SENSE_BUFFERSIZE];
 206         union                   {
 207                 struct c2_inquiry c2;
 208                 struct c4_inquiry c4;
 209                 struct c8_inquiry c8;
 210                 struct c9_inquiry c9;
 211         } inq;
 212 };
 213
 214 static const char *mode[] = {
 215         "RDAC",
 216         "AVT",
 217         "IOSHIP",
 218 };
 219 static const char *lun_state[] =
 220 {
 221         "unowned",
 222         "owned",
 223 };
 224
 225 struct rdac_queue_data {
 226         struct list_head        entry;
 227         struct rdac_dh_data     *h;
 228         activate_complete       callback_fn;
 229         void                    *callback_data;
 230 };
 231
 232 static LIST_HEAD(ctlr_list);
 233 static DEFINE_SPINLOCK(list_lock);
 234 static struct workqueue_struct *kmpath_rdacd;
 235 static void send_mode_select(struct work_struct *work);
 236
 237 /*
 238  * module parameter to enable rdac debug logging.
 239  * 2 bits for each type of logging, only two types defined for now
 240  * Can be enhanced if required at later point
 241  */
 242 static int rdac_logging = 1;
 243 module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
 244 MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
 245                 "Default is 1 - failover logging enabled, "
 246                 "set it to 0xF to enable all the logs");
 247
 248 #define RDAC_LOG_FAILOVER       0
 249 #define RDAC_LOG_SENSE          2
 250
 251 #define RDAC_LOG_BITS           2
 252
 253 #define RDAC_LOG_LEVEL(SHIFT)  \
 254         ((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
 255
 256 #define RDAC_LOG(SHIFT, sdev, f, arg...) \
 257 do { \
 258         if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
 259                 sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
 260 } while (0);
 261
 262 static struct request *get_rdac_req(struct scsi_device *sdev,
 263                         void *buffer, unsigned buflen, int rw)
 264 {
 265         struct request *rq;
 266         struct request_queue *q = sdev->request_queue;
 267
 268         rq = blk_get_request(q, rw, GFP_NOIO);
 269
 270         if (IS_ERR(rq)) {
 271                 sdev_printk(KERN_INFO, sdev,
 272                                 "get_rdac_req: blk_get_request failed.\n");
 273                 return NULL;
 274         }
 275         blk_rq_set_block_pc(rq);
 276
 277         if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
 278                 blk_put_request(rq);
 279                 sdev_printk(KERN_INFO, sdev,
 280                                 "get_rdac_req: blk_rq_map_kern failed.\n");
 281                 return NULL;
 282         }
 283
 284         rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 285                          REQ_FAILFAST_DRIVER;
 286         rq->retries = RDAC_RETRIES;
 287         rq->timeout = RDAC_TIMEOUT;
 288
 289         return rq;
 290 }
 291
 292 static struct request *rdac_failover_get(struct scsi_device *sdev,
 293                         struct rdac_dh_data *h, struct list_head *list)
 294 {
 295         struct request *rq;
 296         struct rdac_mode_common *common;
 297         unsigned data_size;
 298         struct rdac_queue_data *qdata;
 299         u8 *lun_table;
 300
 301         if (h->ctlr->use_ms10) {
 302                 struct rdac_pg_expanded *rdac_pg;
 303
 304                 data_size = sizeof(struct rdac_pg_expanded);
 305                 rdac_pg = &h->ctlr->mode_select.expanded;
 306                 memset(rdac_pg, 0, data_size);
 307                 common = &rdac_pg->common;
 308                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
 309                 rdac_pg->subpage_code = 0x1;
 310                 rdac_pg->page_len[0] = 0x01;
 311                 rdac_pg->page_len[1] = 0x28;
 312                 lun_table = rdac_pg->lun_table;
 313         } else {
 314                 struct rdac_pg_legacy *rdac_pg;
 315
 316                 data_size = sizeof(struct rdac_pg_legacy);
 317                 rdac_pg = &h->ctlr->mode_select.legacy;
 318                 memset(rdac_pg, 0, data_size);
 319                 common = &rdac_pg->common;
 320                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
 321                 rdac_pg->page_len = 0x68;
 322                 lun_table = rdac_pg->lun_table;
 323         }
 324         common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
 325         common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
 326         common->rdac_options = RDAC_FORCED_QUIESENCE;
 327
 328         list_for_each_entry(qdata, list, entry) {
 329                 lun_table[qdata->h->lun] = 0x81;
 330         }
 331
 332         /* get request for block layer packet command */
 333         rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE);
 334         if (!rq)
 335                 return NULL;
 336
 337         /* Prepare the command. */
 338         if (h->ctlr->use_ms10) {
 339                 rq->cmd[0] = MODE_SELECT_10;
 340                 rq->cmd[7] = data_size >> 8;
 341                 rq->cmd[8] = data_size & 0xff;
 342         } else {
 343                 rq->cmd[0] = MODE_SELECT;
 344                 rq->cmd[4] = data_size;
 345         }
 346         rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
 347
 348         rq->sense = h->sense;
 349         memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
 350         rq->sense_len = 0;
 351
 352         return rq;
 353 }
 354
 355 static void release_controller(struct kref *kref)
 356 {
 357         struct rdac_controller *ctlr;
 358         ctlr = container_of(kref, struct rdac_controller, kref);
 359
 360         list_del(&ctlr->node);
 361         kfree(ctlr);
 362 }
 363
 364 static struct rdac_controller *get_controller(int index, char *array_name,
 365                         u8 *array_id, struct scsi_device *sdev)
 366 {
 367         struct rdac_controller *ctlr, *tmp;
 368
 369         list_for_each_entry(tmp, &ctlr_list, node) {
 370                 if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
 371                           (tmp->index == index) &&
 372                           (tmp->host == sdev->host)) {
 373                         kref_get(&tmp->kref);
 374                         return tmp;
 375                 }
 376         }
 377         ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
 378         if (!ctlr)
 379                 return NULL;
 380
 381         /* initialize fields of controller */
 382         memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
 383         ctlr->index = index;
 384         ctlr->host = sdev->host;
 385         memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
 386
 387         kref_init(&ctlr->kref);
 388         ctlr->use_ms10 = -1;
 389         ctlr->ms_queued = 0;
 390         ctlr->ms_sdev = NULL;
 391         spin_lock_init(&ctlr->ms_lock);
 392         INIT_WORK(&ctlr->ms_work, send_mode_select);
 393         INIT_LIST_HEAD(&ctlr->ms_head);
 394         list_add(&ctlr->node, &ctlr_list);
 395
 396         return ctlr;
 397 }
 398
 399 static int submit_inquiry(struct scsi_device *sdev, int page_code,
 400                           unsigned int len, struct rdac_dh_data *h)
 401 {
 402         struct request *rq;
 403         struct request_queue *q = sdev->request_queue;
 404         int err = SCSI_DH_RES_TEMP_UNAVAIL;
 405
 406         rq = get_rdac_req(sdev, &h->inq, len, READ);
 407         if (!rq)
 408                 goto done;
 409
 410         /* Prepare the command. */
 411         rq->cmd[0] = INQUIRY;
 412         rq->cmd[1] = 1;
 413         rq->cmd[2] = page_code;
 414         rq->cmd[4] = len;
 415         rq->cmd_len = COMMAND_SIZE(INQUIRY);
 416
 417         rq->sense = h->sense;
 418         memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
 419         rq->sense_len = 0;
 420
 421         err = blk_execute_rq(q, NULL, rq, 1);
 422         if (err == -EIO)
 423                 err = SCSI_DH_IO;
 424
 425         blk_put_request(rq);
 426 done:
 427         return err;
 428 }
 429
 430 static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
 431                         char *array_name, u8 *array_id)
 432 {
 433         int err, i;
 434         struct c8_inquiry *inqp;
 435
 436         err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h);
 437         if (err == SCSI_DH_OK) {
 438                 inqp = &h->inq.c8;
 439                 if (inqp->page_code != 0xc8)
 440                         return SCSI_DH_NOSYS;
 441                 if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
 442                     inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
 443                         return SCSI_DH_NOSYS;
 444                 h->lun = inqp->lun[7]; /* Uses only the last byte */
 445
 446                 for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
 447                         *(array_name+i) = inqp->array_user_label[(2*i)+1];
 448
 449                 *(array_name+ARRAY_LABEL_LEN-1) = '\0';
 450                 memset(array_id, 0, UNIQUE_ID_LEN);
 451                 memcpy(array_id, inqp->array_unique_id, inqp->array_uniq_id_len);
 452         }
 453         return err;
 454 }
 455
 456 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
 457 {
 458         int err;
 459         struct c9_inquiry *inqp;
 460
 461         h->state = RDAC_STATE_ACTIVE;
 462         err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h);
 463         if (err == SCSI_DH_OK) {
 464                 inqp = &h->inq.c9;
 465                 /* detect the operating mode */
 466                 if ((inqp->avte_cvp >> 5) & 0x1)
 467                         h->mode = RDAC_MODE_IOSHIP; /* LUN in IOSHIP mode */
 468                 else if (inqp->avte_cvp >> 7)
 469                         h->mode = RDAC_MODE_AVT; /* LUN in AVT mode */
 470                 else
 471                         h->mode = RDAC_MODE; /* LUN in RDAC mode */
 472
 473                 /* Update ownership */
 474                 if (inqp->avte_cvp & 0x1)
 475                         h->lun_state = RDAC_LUN_OWNED;
 476                 else {
 477                         h->lun_state = RDAC_LUN_UNOWNED;
 478                         if (h->mode == RDAC_MODE)
 479                                 h->state = RDAC_STATE_PASSIVE;
 480                 }
 481
 482                 /* Update path prio*/
 483                 if (inqp->path_prio & 0x1)
 484                         h->preferred = RDAC_PREFERRED;
 485                 else
 486                         h->preferred = RDAC_NON_PREFERRED;
 487         }
 488
 489         return err;
 490 }
 491
 492 static int initialize_controller(struct scsi_device *sdev,
 493                 struct rdac_dh_data *h, char *array_name, u8 *array_id)
 494 {
 495         int err, index;
 496         struct c4_inquiry *inqp;
 497
 498         err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h);
 499         if (err == SCSI_DH_OK) {
 500                 inqp = &h->inq.c4;
 501                 /* get the controller index */
 502                 if (inqp->slot_id[1] == 0x31)
 503                         index = 0;
 504                 else
 505                         index = 1;
 506
 507                 spin_lock(&list_lock);
 508                 h->ctlr = get_controller(index, array_name, array_id, sdev);
 509                 if (!h->ctlr)
 510                         err = SCSI_DH_RES_TEMP_UNAVAIL;
 511                 spin_unlock(&list_lock);
 512         }
 513         return err;
 514 }
 515
 516 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
 517 {
 518         int err;
 519         struct c2_inquiry *inqp;
 520
 521         err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h);
 522         if (err == SCSI_DH_OK) {
 523                 inqp = &h->inq.c2;
 524                 /*
 525                  * If more than MODE6_MAX_LUN luns are supported, use
 526                  * mode select 10
 527                  */
 528                 if (inqp->max_lun_supported >= MODE6_MAX_LUN)
 529                         h->ctlr->use_ms10 = 1;
 530                 else
 531                         h->ctlr->use_ms10 = 0;
 532         }
 533         return err;
 534 }
 535
 536 static int mode_select_handle_sense(struct scsi_device *sdev,
 537                                         unsigned char *sensebuf)
 538 {
 539         struct scsi_sense_hdr sense_hdr;
 540         int err = SCSI_DH_IO, ret;
 541         struct rdac_dh_data *h = sdev->handler_data;
 542
 543         ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr);
 544         if (!ret)
 545                 goto done;
 546
 547         switch (sense_hdr.sense_key) {
 548         case NO_SENSE:
 549         case ABORTED_COMMAND:
 550         case UNIT_ATTENTION:
 551                 err = SCSI_DH_RETRY;
 552                 break;
 553         case NOT_READY:
 554                 if (sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x01)
 555                         /* LUN Not Ready and is in the Process of Becoming
 556                          * Ready
 557                          */
 558                         err = SCSI_DH_RETRY;
 559                 break;
 560         case ILLEGAL_REQUEST:
 561                 if (sense_hdr.asc == 0x91 && sense_hdr.ascq == 0x36)
 562                         /*
 563                          * Command Lock contention
 564                          */
 565                         err = SCSI_DH_IMM_RETRY;
 566                 break;
 567         default:
 568                 break;
 569         }
 570
 571         RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 572                 "MODE_SELECT returned with sense %02x/%02x/%02x",
 573                 (char *) h->ctlr->array_name, h->ctlr->index,
 574                 sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
 575
 576 done:
 577         return err;
 578 }
 579
 580 static void send_mode_select(struct work_struct *work)
 581 {
 582         struct rdac_controller *ctlr =
 583                 container_of(work, struct rdac_controller, ms_work);
 584         struct request *rq;
 585         struct scsi_device *sdev = ctlr->ms_sdev;
 586         struct rdac_dh_data *h = sdev->handler_data;
 587         struct request_queue *q = sdev->request_queue;
 588         int err, retry_cnt = RDAC_RETRY_COUNT;
 589         struct rdac_queue_data *tmp, *qdata;
 590         LIST_HEAD(list);
 591
 592         spin_lock(&ctlr->ms_lock);
 593         list_splice_init(&ctlr->ms_head, &list);
 594         ctlr->ms_queued = 0;
 595         ctlr->ms_sdev = NULL;
 596         spin_unlock(&ctlr->ms_lock);
 597
 598 retry:
 599         err = SCSI_DH_RES_TEMP_UNAVAIL;
 600         rq = rdac_failover_get(sdev, h, &list);
 601         if (!rq)
 602                 goto done;
 603
 604         RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 605                 "%s MODE_SELECT command",
 606                 (char *) h->ctlr->array_name, h->ctlr->index,
 607                 (retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
 608
 609         err = blk_execute_rq(q, NULL, rq, 1);
 610         blk_put_request(rq);
 611         if (err != SCSI_DH_OK) {
 612                 err = mode_select_handle_sense(sdev, h->sense);
 613                 if (err == SCSI_DH_RETRY && retry_cnt--)
 614                         goto retry;
 615                 if (err == SCSI_DH_IMM_RETRY)
 616                         goto retry;
 617         }
 618         if (err == SCSI_DH_OK) {
 619                 h->state = RDAC_STATE_ACTIVE;
 620                 RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 621                                 "MODE_SELECT completed",
 622                                 (char *) h->ctlr->array_name, h->ctlr->index);
 623         }
 624
 625 done:
 626         list_for_each_entry_safe(qdata, tmp, &list, entry) {
 627                 list_del(&qdata->entry);
 628                 if (err == SCSI_DH_OK)
 629                         qdata->h->state = RDAC_STATE_ACTIVE;
 630                 if (qdata->callback_fn)
 631                         qdata->callback_fn(qdata->callback_data, err);
 632                 kfree(qdata);
 633         }
 634         return;
 635 }
 636
 637 static int queue_mode_select(struct scsi_device *sdev,
 638                                 activate_complete fn, void *data)
 639 {
 640         struct rdac_queue_data *qdata;
 641         struct rdac_controller *ctlr;
 642
 643         qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
 644         if (!qdata)
 645                 return SCSI_DH_RETRY;
 646
 647         qdata->h = sdev->handler_data;
 648         qdata->callback_fn = fn;
 649         qdata->callback_data = data;
 650
 651         ctlr = qdata->h->ctlr;
 652         spin_lock(&ctlr->ms_lock);
 653         list_add_tail(&qdata->entry, &ctlr->ms_head);
 654         if (!ctlr->ms_queued) {
 655                 ctlr->ms_queued = 1;
 656                 ctlr->ms_sdev = sdev;
 657                 queue_work(kmpath_rdacd, &ctlr->ms_work);
 658         }
 659         spin_unlock(&ctlr->ms_lock);
 660         return SCSI_DH_OK;
 661 }
 662
 663 static int rdac_activate(struct scsi_device *sdev,
 664                         activate_complete fn, void *data)
 665 {
 666         struct rdac_dh_data *h = sdev->handler_data;
 667         int err = SCSI_DH_OK;
 668         int act = 0;
 669
 670         err = check_ownership(sdev, h);
 671         if (err != SCSI_DH_OK)
 672                 goto done;
 673
 674         switch (h->mode) {
 675         case RDAC_MODE:
 676                 if (h->lun_state == RDAC_LUN_UNOWNED)
 677                         act = 1;
 678                 break;
 679         case RDAC_MODE_IOSHIP:
 680                 if ((h->lun_state == RDAC_LUN_UNOWNED) &&
 681                     (h->preferred == RDAC_PREFERRED))
 682                         act = 1;
 683                 break;
 684         default:
 685                 break;
 686         }
 687
 688         if (act) {
 689                 err = queue_mode_select(sdev, fn, data);
 690                 if (err == SCSI_DH_OK)
 691                         return 0;
 692         }
 693 done:
 694         if (fn)
 695                 fn(data, err);
 696         return 0;
 697 }
 698
 699 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
 700 {
 701         struct rdac_dh_data *h = sdev->handler_data;
 702         int ret = BLKPREP_OK;
 703
 704         if (h->state != RDAC_STATE_ACTIVE) {
 705                 ret = BLKPREP_KILL;
 706                 req->cmd_flags |= REQ_QUIET;
 707         }
 708         return ret;
 709
 710 }
 711
 712 static int rdac_check_sense(struct scsi_device *sdev,
 713                                 struct scsi_sense_hdr *sense_hdr)
 714 {
 715         struct rdac_dh_data *h = sdev->handler_data;
 716
 717         RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
 718                         "I/O returned with sense %02x/%02x/%02x",
 719                         (char *) h->ctlr->array_name, h->ctlr->index,
 720                         sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 721
 722         switch (sense_hdr->sense_key) {
 723         case NOT_READY:
 724                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
 725                         /* LUN Not Ready - Logical Unit Not Ready and is in
 726                         * the process of becoming ready
 727                         * Just retry.
 728                         */
 729                         return ADD_TO_MLQUEUE;
 730                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
 731                         /* LUN Not Ready - Storage firmware incompatible
 732                          * Manual code synchonisation required.
 733                          *
 734                          * Nothing we can do here. Try to bypass the path.
 735                          */
 736                         return SUCCESS;
 737                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
 738                         /* LUN Not Ready - Quiescense in progress
 739                          *
 740                          * Just retry and wait.
 741                          */
 742                         return ADD_TO_MLQUEUE;
 743                 if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
 744                         /* LUN Not Ready - Quiescense in progress
 745                          * or has been achieved
 746                          * Just retry.
 747                          */
 748                         return ADD_TO_MLQUEUE;
 749                 break;
 750         case ILLEGAL_REQUEST:
 751                 if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
 752                         /* Invalid Request - Current Logical Unit Ownership.
 753                          * Controller is not the current owner of the LUN,
 754                          * Fail the path, so that the other path be used.
 755                          */
 756                         h->state = RDAC_STATE_PASSIVE;
 757                         return SUCCESS;
 758                 }
 759                 break;
 760         case UNIT_ATTENTION:
 761                 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 762                         /*
 763                          * Power On, Reset, or Bus Device Reset, just retry.
 764                          */
 765                         return ADD_TO_MLQUEUE;
 766                 if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
 767                         /*
 768                          * Quiescence in progress , just retry.
 769                          */
 770                         return ADD_TO_MLQUEUE;
 771                 break;
 772         }
 773         /* success just means we do not care what scsi-ml does */
 774         return SCSI_RETURN_NOT_HANDLED;
 775 }
 776
 777 static int rdac_bus_attach(struct scsi_device *sdev)
 778 {
 779         struct rdac_dh_data *h;
 780         int err;
 781         char array_name[ARRAY_LABEL_LEN];
 782         char array_id[UNIQUE_ID_LEN];
 783
 784         h = kzalloc(sizeof(*h) , GFP_KERNEL);
 785         if (!h)
 786                 return -ENOMEM;
 787         h->lun = UNINITIALIZED_LUN;
 788         h->state = RDAC_STATE_ACTIVE;
 789
 790         err = get_lun_info(sdev, h, array_name, array_id);
 791         if (err != SCSI_DH_OK)
 792                 goto failed;
 793
 794         err = initialize_controller(sdev, h, array_name, array_id);
 795         if (err != SCSI_DH_OK)
 796                 goto failed;
 797
 798         err = check_ownership(sdev, h);
 799         if (err != SCSI_DH_OK)
 800                 goto clean_ctlr;
 801
 802         err = set_mode_select(sdev, h);
 803         if (err != SCSI_DH_OK)
 804                 goto clean_ctlr;
 805
 806         sdev_printk(KERN_NOTICE, sdev,
 807                     "%s: LUN %d (%s) (%s)\n",
 808                     RDAC_NAME, h->lun, mode[(int)h->mode],
 809                     lun_state[(int)h->lun_state]);
 810
 811         sdev->handler_data = h;
 812         return 0;
 813
 814 clean_ctlr:
 815         spin_lock(&list_lock);
 816         kref_put(&h->ctlr->kref, release_controller);
 817         spin_unlock(&list_lock);
 818
 819 failed:
 820         kfree(h);
 821         return -EINVAL;
 822 }
 823
 824 static void rdac_bus_detach( struct scsi_device *sdev )
 825 {
 826         struct rdac_dh_data *h = sdev->handler_data;
 827
 828         if (h->ctlr && h->ctlr->ms_queued)
 829                 flush_workqueue(kmpath_rdacd);
 830
 831         spin_lock(&list_lock);
 832         if (h->ctlr)
 833                 kref_put(&h->ctlr->kref, release_controller);
 834         spin_unlock(&list_lock);
 835         sdev->handler_data = NULL;
 836         kfree(h);
 837 }
 838
 839 static struct scsi_device_handler rdac_dh = {
 840         .name = RDAC_NAME,
 841         .module = THIS_MODULE,
 842         .prep_fn = rdac_prep_fn,
 843         .check_sense = rdac_check_sense,
 844         .attach = rdac_bus_attach,
 845         .detach = rdac_bus_detach,
 846         .activate = rdac_activate,
 847 };
 848
 849 static int __init rdac_init(void)
 850 {
 851         int r;
 852
 853         r = scsi_register_device_handler(&rdac_dh);
 854         if (r != 0) {
 855                 printk(KERN_ERR "Failed to register scsi device handler.");
 856                 goto done;
 857         }
 858
 859         /*
 860          * Create workqueue to handle mode selects for rdac
 861          */
 862         kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
 863         if (!kmpath_rdacd) {
 864                 scsi_unregister_device_handler(&rdac_dh);
 865                 printk(KERN_ERR "kmpath_rdacd creation failed.\n");
 866
 867                 r = -EINVAL;
 868         }
 869 done:
 870         return r;
 871 }
 872
 873 static void __exit rdac_exit(void)
 874 {
 875         destroy_workqueue(kmpath_rdacd);
 876         scsi_unregister_device_handler(&rdac_dh);
 877 }
 878
 879 module_init(rdac_init);
 880 module_exit(rdac_exit);
 881
 882 MODULE_DESCRIPTION("Multipath LSI/Engenio/NetApp E-Series RDAC driver");
 883 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
 884 MODULE_VERSION("01.00.0000.0000");
 885 MODULE_LICENSE("GPL");