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         unsigned char           sense[SCSI_SENSE_BUFFERSIZE];
 209         union                   {
 210                 struct c2_inquiry c2;
 211                 struct c4_inquiry c4;
 212                 struct c8_inquiry c8;
 213                 struct c9_inquiry c9;
 214         } inq;
 215 };
 216
 217 static const char *mode[] = {
 218         "RDAC",
 219         "AVT",
 220         "IOSHIP",
 221 };
 222 static const char *lun_state[] =
 223 {
 224         "unowned",
 225         "owned",
 226 };
 227
 228 struct rdac_queue_data {
 229         struct list_head        entry;
 230         struct rdac_dh_data     *h;
 231         activate_complete       callback_fn;
 232         void                    *callback_data;
 233 };
 234
 235 static LIST_HEAD(ctlr_list);
 236 static DEFINE_SPINLOCK(list_lock);
 237 static struct workqueue_struct *kmpath_rdacd;
 238 static void send_mode_select(struct work_struct *work);
 239
 240 /*
 241  * module parameter to enable rdac debug logging.
 242  * 2 bits for each type of logging, only two types defined for now
 243  * Can be enhanced if required at later point
 244  */
 245 static int rdac_logging = 1;
 246 module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
 247 MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
 248                 "Default is 1 - failover logging enabled, "
 249                 "set it to 0xF to enable all the logs");
 250
 251 #define RDAC_LOG_FAILOVER       0
 252 #define RDAC_LOG_SENSE          2
 253
 254 #define RDAC_LOG_BITS           2
 255
 256 #define RDAC_LOG_LEVEL(SHIFT)  \
 257         ((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
 258
 259 #define RDAC_LOG(SHIFT, sdev, f, arg...) \
 260 do { \
 261         if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
 262                 sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
 263 } while (0);
 264
 265 static struct request *get_rdac_req(struct scsi_device *sdev,
 266                         void *buffer, unsigned buflen, int rw)
 267 {
 268         struct request *rq;
 269         struct request_queue *q = sdev->request_queue;
 270
 271         rq = blk_get_request(q, rw, GFP_NOIO);
 272
 273         if (IS_ERR(rq)) {
 274                 sdev_printk(KERN_INFO, sdev,
 275                                 "get_rdac_req: blk_get_request failed.\n");
 276                 return NULL;
 277         }
 278         blk_rq_set_block_pc(rq);
 279
 280         if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
 281                 blk_put_request(rq);
 282                 sdev_printk(KERN_INFO, sdev,
 283                                 "get_rdac_req: blk_rq_map_kern failed.\n");
 284                 return NULL;
 285         }
 286
 287         rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 288                          REQ_FAILFAST_DRIVER;
 289         rq->retries = RDAC_RETRIES;
 290         rq->timeout = RDAC_TIMEOUT;
 291
 292         return rq;
 293 }
 294
 295 static struct request *rdac_failover_get(struct scsi_device *sdev,
 296                         struct rdac_dh_data *h, struct list_head *list)
 297 {
 298         struct request *rq;
 299         struct rdac_mode_common *common;
 300         unsigned data_size;
 301         struct rdac_queue_data *qdata;
 302         u8 *lun_table;
 303
 304         if (h->ctlr->use_ms10) {
 305                 struct rdac_pg_expanded *rdac_pg;
 306
 307                 data_size = sizeof(struct rdac_pg_expanded);
 308                 rdac_pg = &h->ctlr->mode_select.expanded;
 309                 memset(rdac_pg, 0, data_size);
 310                 common = &rdac_pg->common;
 311                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
 312                 rdac_pg->subpage_code = 0x1;
 313                 rdac_pg->page_len[0] = 0x01;
 314                 rdac_pg->page_len[1] = 0x28;
 315                 lun_table = rdac_pg->lun_table;
 316         } else {
 317                 struct rdac_pg_legacy *rdac_pg;
 318
 319                 data_size = sizeof(struct rdac_pg_legacy);
 320                 rdac_pg = &h->ctlr->mode_select.legacy;
 321                 memset(rdac_pg, 0, data_size);
 322                 common = &rdac_pg->common;
 323                 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
 324                 rdac_pg->page_len = 0x68;
 325                 lun_table = rdac_pg->lun_table;
 326         }
 327         common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
 328         common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
 329         common->rdac_options = RDAC_FORCED_QUIESENCE;
 330
 331         list_for_each_entry(qdata, list, entry) {
 332                 lun_table[qdata->h->lun] = 0x81;
 333         }
 334
 335         /* get request for block layer packet command */
 336         rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE);
 337         if (!rq)
 338                 return NULL;
 339
 340         /* Prepare the command. */
 341         if (h->ctlr->use_ms10) {
 342                 rq->cmd[0] = MODE_SELECT_10;
 343                 rq->cmd[7] = data_size >> 8;
 344                 rq->cmd[8] = data_size & 0xff;
 345         } else {
 346                 rq->cmd[0] = MODE_SELECT;
 347                 rq->cmd[4] = data_size;
 348         }
 349         rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
 350
 351         rq->sense = h->sense;
 352         memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
 353         rq->sense_len = 0;
 354
 355         return rq;
 356 }
 357
 358 static void release_controller(struct kref *kref)
 359 {
 360         struct rdac_controller *ctlr;
 361         ctlr = container_of(kref, struct rdac_controller, kref);
 362
 363         list_del(&ctlr->node);
 364         kfree(ctlr);
 365 }
 366
 367 static struct rdac_controller *get_controller(int index, char *array_name,
 368                         u8 *array_id, struct scsi_device *sdev)
 369 {
 370         struct rdac_controller *ctlr, *tmp;
 371
 372         list_for_each_entry(tmp, &ctlr_list, node) {
 373                 if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
 374                           (tmp->index == index) &&
 375                           (tmp->host == sdev->host)) {
 376                         kref_get(&tmp->kref);
 377                         return tmp;
 378                 }
 379         }
 380         ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
 381         if (!ctlr)
 382                 return NULL;
 383
 384         /* initialize fields of controller */
 385         memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
 386         ctlr->index = index;
 387         ctlr->host = sdev->host;
 388         memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
 389
 390         kref_init(&ctlr->kref);
 391         ctlr->use_ms10 = -1;
 392         ctlr->ms_queued = 0;
 393         ctlr->ms_sdev = NULL;
 394         spin_lock_init(&ctlr->ms_lock);
 395         INIT_WORK(&ctlr->ms_work, send_mode_select);
 396         INIT_LIST_HEAD(&ctlr->ms_head);
 397         list_add(&ctlr->node, &ctlr_list);
 398         INIT_LIST_HEAD(&ctlr->dh_list);
 399
 400         return ctlr;
 401 }
 402
 403 static int submit_inquiry(struct scsi_device *sdev, int page_code,
 404                           unsigned int len, struct rdac_dh_data *h)
 405 {
 406         struct request *rq;
 407         struct request_queue *q = sdev->request_queue;
 408         int err = SCSI_DH_RES_TEMP_UNAVAIL;
 409
 410         rq = get_rdac_req(sdev, &h->inq, len, READ);
 411         if (!rq)
 412                 goto done;
 413
 414         /* Prepare the command. */
 415         rq->cmd[0] = INQUIRY;
 416         rq->cmd[1] = 1;
 417         rq->cmd[2] = page_code;
 418         rq->cmd[4] = len;
 419         rq->cmd_len = COMMAND_SIZE(INQUIRY);
 420
 421         rq->sense = h->sense;
 422         memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
 423         rq->sense_len = 0;
 424
 425         err = blk_execute_rq(q, NULL, rq, 1);
 426         if (err == -EIO)
 427                 err = SCSI_DH_IO;
 428
 429         blk_put_request(rq);
 430 done:
 431         return err;
 432 }
 433
 434 static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
 435                         char *array_name, u8 *array_id)
 436 {
 437         int err, i;
 438         struct c8_inquiry *inqp;
 439
 440         err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h);
 441         if (err == SCSI_DH_OK) {
 442                 inqp = &h->inq.c8;
 443                 if (inqp->page_code != 0xc8)
 444                         return SCSI_DH_NOSYS;
 445                 if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
 446                     inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
 447                         return SCSI_DH_NOSYS;
 448                 h->lun = inqp->lun[7]; /* Uses only the last byte */
 449
 450                 for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
 451                         *(array_name+i) = inqp->array_user_label[(2*i)+1];
 452
 453                 *(array_name+ARRAY_LABEL_LEN-1) = '\0';
 454                 memset(array_id, 0, UNIQUE_ID_LEN);
 455                 memcpy(array_id, inqp->array_unique_id, inqp->array_uniq_id_len);
 456         }
 457         return err;
 458 }
 459
 460 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
 461 {
 462         int err, access_state;
 463         struct rdac_dh_data *tmp;
 464         struct c9_inquiry *inqp;
 465
 466         h->state = RDAC_STATE_ACTIVE;
 467         err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h);
 468         if (err == SCSI_DH_OK) {
 469                 inqp = &h->inq.c9;
 470                 /* detect the operating mode */
 471                 if ((inqp->avte_cvp >> 5) & 0x1)
 472                         h->mode = RDAC_MODE_IOSHIP; /* LUN in IOSHIP mode */
 473                 else if (inqp->avte_cvp >> 7)
 474                         h->mode = RDAC_MODE_AVT; /* LUN in AVT mode */
 475                 else
 476                         h->mode = RDAC_MODE; /* LUN in RDAC mode */
 477
 478                 /* Update ownership */
 479                 if (inqp->avte_cvp & 0x1) {
 480                         h->lun_state = RDAC_LUN_OWNED;
 481                         access_state = SCSI_ACCESS_STATE_OPTIMAL;
 482                 } else {
 483                         h->lun_state = RDAC_LUN_UNOWNED;
 484                         if (h->mode == RDAC_MODE) {
 485                                 h->state = RDAC_STATE_PASSIVE;
 486                                 access_state = SCSI_ACCESS_STATE_STANDBY;
 487                         } else
 488                                 access_state = SCSI_ACCESS_STATE_ACTIVE;
 489                 }
 490
 491                 /* Update path prio*/
 492                 if (inqp->path_prio & 0x1) {
 493                         h->preferred = RDAC_PREFERRED;
 494                         access_state |= SCSI_ACCESS_STATE_PREFERRED;
 495                 } else
 496                         h->preferred = RDAC_NON_PREFERRED;
 497                 rcu_read_lock();
 498                 list_for_each_entry_rcu(tmp, &h->ctlr->dh_list, node) {
 499                         /* h->sdev should always be valid */
 500                         BUG_ON(!tmp->sdev);
 501                         tmp->sdev->access_state = access_state;
 502                 }
 503                 rcu_read_unlock();
 504         }
 505
 506         return err;
 507 }
 508
 509 static int initialize_controller(struct scsi_device *sdev,
 510                 struct rdac_dh_data *h, char *array_name, u8 *array_id)
 511 {
 512         int err, index;
 513         struct c4_inquiry *inqp;
 514
 515         err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h);
 516         if (err == SCSI_DH_OK) {
 517                 inqp = &h->inq.c4;
 518                 /* get the controller index */
 519                 if (inqp->slot_id[1] == 0x31)
 520                         index = 0;
 521                 else
 522                         index = 1;
 523
 524                 spin_lock(&list_lock);
 525                 h->ctlr = get_controller(index, array_name, array_id, sdev);
 526                 if (!h->ctlr)
 527                         err = SCSI_DH_RES_TEMP_UNAVAIL;
 528                 else {
 529                         list_add_rcu(&h->node, &h->ctlr->dh_list);
 530                         h->sdev = sdev;
 531                 }
 532                 spin_unlock(&list_lock);
 533         }
 534         return err;
 535 }
 536
 537 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
 538 {
 539         int err;
 540         struct c2_inquiry *inqp;
 541
 542         err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h);
 543         if (err == SCSI_DH_OK) {
 544                 inqp = &h->inq.c2;
 545                 /*
 546                  * If more than MODE6_MAX_LUN luns are supported, use
 547                  * mode select 10
 548                  */
 549                 if (inqp->max_lun_supported >= MODE6_MAX_LUN)
 550                         h->ctlr->use_ms10 = 1;
 551                 else
 552                         h->ctlr->use_ms10 = 0;
 553         }
 554         return err;
 555 }
 556
 557 static int mode_select_handle_sense(struct scsi_device *sdev,
 558                                         unsigned char *sensebuf)
 559 {
 560         struct scsi_sense_hdr sense_hdr;
 561         int err = SCSI_DH_IO, ret;
 562         struct rdac_dh_data *h = sdev->handler_data;
 563
 564         ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr);
 565         if (!ret)
 566                 goto done;
 567
 568         switch (sense_hdr.sense_key) {
 569         case NO_SENSE:
 570         case ABORTED_COMMAND:
 571         case UNIT_ATTENTION:
 572                 err = SCSI_DH_RETRY;
 573                 break;
 574         case NOT_READY:
 575                 if (sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x01)
 576                         /* LUN Not Ready and is in the Process of Becoming
 577                          * Ready
 578                          */
 579                         err = SCSI_DH_RETRY;
 580                 break;
 581         case ILLEGAL_REQUEST:
 582                 if (sense_hdr.asc == 0x91 && sense_hdr.ascq == 0x36)
 583                         /*
 584                          * Command Lock contention
 585                          */
 586                         err = SCSI_DH_IMM_RETRY;
 587                 break;
 588         default:
 589                 break;
 590         }
 591
 592         RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 593                 "MODE_SELECT returned with sense %02x/%02x/%02x",
 594                 (char *) h->ctlr->array_name, h->ctlr->index,
 595                 sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
 596
 597 done:
 598         return err;
 599 }
 600
 601 static void send_mode_select(struct work_struct *work)
 602 {
 603         struct rdac_controller *ctlr =
 604                 container_of(work, struct rdac_controller, ms_work);
 605         struct request *rq;
 606         struct scsi_device *sdev = ctlr->ms_sdev;
 607         struct rdac_dh_data *h = sdev->handler_data;
 608         struct request_queue *q = sdev->request_queue;
 609         int err, retry_cnt = RDAC_RETRY_COUNT;
 610         struct rdac_queue_data *tmp, *qdata;
 611         LIST_HEAD(list);
 612
 613         spin_lock(&ctlr->ms_lock);
 614         list_splice_init(&ctlr->ms_head, &list);
 615         ctlr->ms_queued = 0;
 616         ctlr->ms_sdev = NULL;
 617         spin_unlock(&ctlr->ms_lock);
 618
 619 retry:
 620         err = SCSI_DH_RES_TEMP_UNAVAIL;
 621         rq = rdac_failover_get(sdev, h, &list);
 622         if (!rq)
 623                 goto done;
 624
 625         RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 626                 "%s MODE_SELECT command",
 627                 (char *) h->ctlr->array_name, h->ctlr->index,
 628                 (retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
 629
 630         err = blk_execute_rq(q, NULL, rq, 1);
 631         blk_put_request(rq);
 632         if (err != SCSI_DH_OK) {
 633                 err = mode_select_handle_sense(sdev, h->sense);
 634                 if (err == SCSI_DH_RETRY && retry_cnt--)
 635                         goto retry;
 636                 if (err == SCSI_DH_IMM_RETRY)
 637                         goto retry;
 638         }
 639         if (err == SCSI_DH_OK) {
 640                 h->state = RDAC_STATE_ACTIVE;
 641                 RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 642                                 "MODE_SELECT completed",
 643                                 (char *) h->ctlr->array_name, h->ctlr->index);
 644         }
 645
 646 done:
 647         list_for_each_entry_safe(qdata, tmp, &list, entry) {
 648                 list_del(&qdata->entry);
 649                 if (err == SCSI_DH_OK)
 650                         qdata->h->state = RDAC_STATE_ACTIVE;
 651                 if (qdata->callback_fn)
 652                         qdata->callback_fn(qdata->callback_data, err);
 653                 kfree(qdata);
 654         }
 655         return;
 656 }
 657
 658 static int queue_mode_select(struct scsi_device *sdev,
 659                                 activate_complete fn, void *data)
 660 {
 661         struct rdac_queue_data *qdata;
 662         struct rdac_controller *ctlr;
 663
 664         qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
 665         if (!qdata)
 666                 return SCSI_DH_RETRY;
 667
 668         qdata->h = sdev->handler_data;
 669         qdata->callback_fn = fn;
 670         qdata->callback_data = data;
 671
 672         ctlr = qdata->h->ctlr;
 673         spin_lock(&ctlr->ms_lock);
 674         list_add_tail(&qdata->entry, &ctlr->ms_head);
 675         if (!ctlr->ms_queued) {
 676                 ctlr->ms_queued = 1;
 677                 ctlr->ms_sdev = sdev;
 678                 queue_work(kmpath_rdacd, &ctlr->ms_work);
 679         }
 680         spin_unlock(&ctlr->ms_lock);
 681         return SCSI_DH_OK;
 682 }
 683
 684 static int rdac_activate(struct scsi_device *sdev,
 685                         activate_complete fn, void *data)
 686 {
 687         struct rdac_dh_data *h = sdev->handler_data;
 688         int err = SCSI_DH_OK;
 689         int act = 0;
 690
 691         err = check_ownership(sdev, h);
 692         if (err != SCSI_DH_OK)
 693                 goto done;
 694
 695         switch (h->mode) {
 696         case RDAC_MODE:
 697                 if (h->lun_state == RDAC_LUN_UNOWNED)
 698                         act = 1;
 699                 break;
 700         case RDAC_MODE_IOSHIP:
 701                 if ((h->lun_state == RDAC_LUN_UNOWNED) &&
 702                     (h->preferred == RDAC_PREFERRED))
 703                         act = 1;
 704                 break;
 705         default:
 706                 break;
 707         }
 708
 709         if (act) {
 710                 err = queue_mode_select(sdev, fn, data);
 711                 if (err == SCSI_DH_OK)
 712                         return 0;
 713         }
 714 done:
 715         if (fn)
 716                 fn(data, err);
 717         return 0;
 718 }
 719
 720 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
 721 {
 722         struct rdac_dh_data *h = sdev->handler_data;
 723         int ret = BLKPREP_OK;
 724
 725         if (h->state != RDAC_STATE_ACTIVE) {
 726                 ret = BLKPREP_KILL;
 727                 req->cmd_flags |= REQ_QUIET;
 728         }
 729         return ret;
 730
 731 }
 732
 733 static int rdac_check_sense(struct scsi_device *sdev,
 734                                 struct scsi_sense_hdr *sense_hdr)
 735 {
 736         struct rdac_dh_data *h = sdev->handler_data;
 737
 738         RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
 739                         "I/O returned with sense %02x/%02x/%02x",
 740                         (char *) h->ctlr->array_name, h->ctlr->index,
 741                         sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 742
 743         switch (sense_hdr->sense_key) {
 744         case NOT_READY:
 745                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
 746                         /* LUN Not Ready - Logical Unit Not Ready and is in
 747                         * the process of becoming ready
 748                         * Just retry.
 749                         */
 750                         return ADD_TO_MLQUEUE;
 751                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
 752                         /* LUN Not Ready - Storage firmware incompatible
 753                          * Manual code synchonisation required.
 754                          *
 755                          * Nothing we can do here. Try to bypass the path.
 756                          */
 757                         return SUCCESS;
 758                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
 759                         /* LUN Not Ready - Quiescense in progress
 760                          *
 761                          * Just retry and wait.
 762                          */
 763                         return ADD_TO_MLQUEUE;
 764                 if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
 765                         /* LUN Not Ready - Quiescense in progress
 766                          * or has been achieved
 767                          * Just retry.
 768                          */
 769                         return ADD_TO_MLQUEUE;
 770                 break;
 771         case ILLEGAL_REQUEST:
 772                 if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
 773                         /* Invalid Request - Current Logical Unit Ownership.
 774                          * Controller is not the current owner of the LUN,
 775                          * Fail the path, so that the other path be used.
 776                          */
 777                         h->state = RDAC_STATE_PASSIVE;
 778                         return SUCCESS;
 779                 }
 780                 break;
 781         case UNIT_ATTENTION:
 782                 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 783                         /*
 784                          * Power On, Reset, or Bus Device Reset, just retry.
 785                          */
 786                         return ADD_TO_MLQUEUE;
 787                 if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
 788                         /*
 789                          * Quiescence in progress , just retry.
 790                          */
 791                         return ADD_TO_MLQUEUE;
 792                 break;
 793         }
 794         /* success just means we do not care what scsi-ml does */
 795         return SCSI_RETURN_NOT_HANDLED;
 796 }
 797
 798 static int rdac_bus_attach(struct scsi_device *sdev)
 799 {
 800         struct rdac_dh_data *h;
 801         int err;
 802         char array_name[ARRAY_LABEL_LEN];
 803         char array_id[UNIQUE_ID_LEN];
 804
 805         h = kzalloc(sizeof(*h) , GFP_KERNEL);
 806         if (!h)
 807                 return -ENOMEM;
 808         h->lun = UNINITIALIZED_LUN;
 809         h->state = RDAC_STATE_ACTIVE;
 810
 811         err = get_lun_info(sdev, h, array_name, array_id);
 812         if (err != SCSI_DH_OK)
 813                 goto failed;
 814
 815         err = initialize_controller(sdev, h, array_name, array_id);
 816         if (err != SCSI_DH_OK)
 817                 goto failed;
 818
 819         err = check_ownership(sdev, h);
 820         if (err != SCSI_DH_OK)
 821                 goto clean_ctlr;
 822
 823         err = set_mode_select(sdev, h);
 824         if (err != SCSI_DH_OK)
 825                 goto clean_ctlr;
 826
 827         sdev_printk(KERN_NOTICE, sdev,
 828                     "%s: LUN %d (%s) (%s)\n",
 829                     RDAC_NAME, h->lun, mode[(int)h->mode],
 830                     lun_state[(int)h->lun_state]);
 831
 832         sdev->handler_data = h;
 833         return 0;
 834
 835 clean_ctlr:
 836         spin_lock(&list_lock);
 837         kref_put(&h->ctlr->kref, release_controller);
 838         spin_unlock(&list_lock);
 839
 840 failed:
 841         kfree(h);
 842         return -EINVAL;
 843 }
 844
 845 static void rdac_bus_detach( struct scsi_device *sdev )
 846 {
 847         struct rdac_dh_data *h = sdev->handler_data;
 848
 849         if (h->ctlr && h->ctlr->ms_queued)
 850                 flush_workqueue(kmpath_rdacd);
 851
 852         spin_lock(&list_lock);
 853         if (h->ctlr) {
 854                 list_del_rcu(&h->node);
 855                 h->sdev = NULL;
 856                 kref_put(&h->ctlr->kref, release_controller);
 857         }
 858         spin_unlock(&list_lock);
 859         sdev->handler_data = NULL;
 860         kfree(h);
 861 }
 862
 863 static struct scsi_device_handler rdac_dh = {
 864         .name = RDAC_NAME,
 865         .module = THIS_MODULE,
 866         .prep_fn = rdac_prep_fn,
 867         .check_sense = rdac_check_sense,
 868         .attach = rdac_bus_attach,
 869         .detach = rdac_bus_detach,
 870         .activate = rdac_activate,
 871 };
 872
 873 static int __init rdac_init(void)
 874 {
 875         int r;
 876
 877         r = scsi_register_device_handler(&rdac_dh);
 878         if (r != 0) {
 879                 printk(KERN_ERR "Failed to register scsi device handler.");
 880                 goto done;
 881         }
 882
 883         /*
 884          * Create workqueue to handle mode selects for rdac
 885          */
 886         kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
 887         if (!kmpath_rdacd) {
 888                 scsi_unregister_device_handler(&rdac_dh);
 889                 printk(KERN_ERR "kmpath_rdacd creation failed.\n");
 890
 891                 r = -EINVAL;
 892         }
 893 done:
 894         return r;
 895 }
 896
 897 static void __exit rdac_exit(void)
 898 {
 899         destroy_workqueue(kmpath_rdacd);
 900         scsi_unregister_device_handler(&rdac_dh);
 901 }
 902
 903 module_init(rdac_init);
 904 module_exit(rdac_exit);
 905
 906 MODULE_DESCRIPTION("Multipath LSI/Engenio/NetApp E-Series RDAC driver");
 907 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
 908 MODULE_VERSION("01.00.0000.0000");
 909 MODULE_LICENSE("GPL");