linux/drivers/scsi/device_handler/scsi_dh_rdac.c
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   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
  58struct rdac_mode_6_hdr {
  59        u8      data_len;
  60        u8      medium_type;
  61        u8      device_params;
  62        u8      block_desc_len;
  63};
  64
  65struct 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
  73struct 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
  82struct 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
  94struct 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
 105struct 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
 120struct 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
 133struct 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
 151struct 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
 171struct 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
 184struct rdac_dh_data {
 185        struct list_head        node;
 186        struct rdac_controller  *ctlr;
 187        struct scsi_device      *sdev;
 188#define UNINITIALIZED_LUN       (1 << 8)
 189        unsigned                lun;
 190
 191#define RDAC_MODE               0
 192#define RDAC_MODE_AVT           1
 193#define RDAC_MODE_IOSHIP        2
 194        unsigned char           mode;
 195
 196#define RDAC_STATE_ACTIVE       0
 197#define RDAC_STATE_PASSIVE      1
 198        unsigned char           state;
 199
 200#define RDAC_LUN_UNOWNED        0
 201#define RDAC_LUN_OWNED          1
 202        char                    lun_state;
 203
 204#define RDAC_PREFERRED          0
 205#define RDAC_NON_PREFERRED      1
 206        char                    preferred;
 207
 208        union                   {
 209                struct c2_inquiry c2;
 210                struct c4_inquiry c4;
 211                struct c8_inquiry c8;
 212                struct c9_inquiry c9;
 213        } inq;
 214};
 215
 216static const char *mode[] = {
 217        "RDAC",
 218        "AVT",
 219        "IOSHIP",
 220};
 221static const char *lun_state[] =
 222{
 223        "unowned",
 224        "owned",
 225};
 226
 227struct rdac_queue_data {
 228        struct list_head        entry;
 229        struct rdac_dh_data     *h;
 230        activate_complete       callback_fn;
 231        void                    *callback_data;
 232};
 233
 234static LIST_HEAD(ctlr_list);
 235static DEFINE_SPINLOCK(list_lock);
 236static struct workqueue_struct *kmpath_rdacd;
 237static void send_mode_select(struct work_struct *work);
 238
 239/*
 240 * module parameter to enable rdac debug logging.
 241 * 2 bits for each type of logging, only two types defined for now
 242 * Can be enhanced if required at later point
 243 */
 244static int rdac_logging = 1;
 245module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
 246MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
 247                "Default is 1 - failover logging enabled, "
 248                "set it to 0xF to enable all the logs");
 249
 250#define RDAC_LOG_FAILOVER       0
 251#define RDAC_LOG_SENSE          2
 252
 253#define RDAC_LOG_BITS           2
 254
 255#define RDAC_LOG_LEVEL(SHIFT)  \
 256        ((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
 257
 258#define RDAC_LOG(SHIFT, sdev, f, arg...) \
 259do { \
 260        if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
 261                sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
 262} while (0);
 263
 264static unsigned int rdac_failover_get(struct rdac_controller *ctlr,
 265                                      struct list_head *list,
 266                                      unsigned char *cdb)
 267{
 268        struct rdac_mode_common *common;
 269        unsigned data_size;
 270        struct rdac_queue_data *qdata;
 271        u8 *lun_table;
 272
 273        if (ctlr->use_ms10) {
 274                struct rdac_pg_expanded *rdac_pg;
 275
 276                data_size = sizeof(struct rdac_pg_expanded);
 277                rdac_pg = &ctlr->mode_select.expanded;
 278                memset(rdac_pg, 0, data_size);
 279                common = &rdac_pg->common;
 280                rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
 281                rdac_pg->subpage_code = 0x1;
 282                rdac_pg->page_len[0] = 0x01;
 283                rdac_pg->page_len[1] = 0x28;
 284                lun_table = rdac_pg->lun_table;
 285        } else {
 286                struct rdac_pg_legacy *rdac_pg;
 287
 288                data_size = sizeof(struct rdac_pg_legacy);
 289                rdac_pg = &ctlr->mode_select.legacy;
 290                memset(rdac_pg, 0, data_size);
 291                common = &rdac_pg->common;
 292                rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
 293                rdac_pg->page_len = 0x68;
 294                lun_table = rdac_pg->lun_table;
 295        }
 296        common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
 297        common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
 298        common->rdac_options = RDAC_FORCED_QUIESENCE;
 299
 300        list_for_each_entry(qdata, list, entry) {
 301                lun_table[qdata->h->lun] = 0x81;
 302        }
 303
 304        /* Prepare the command. */
 305        if (ctlr->use_ms10) {
 306                cdb[0] = MODE_SELECT_10;
 307                cdb[7] = data_size >> 8;
 308                cdb[8] = data_size & 0xff;
 309        } else {
 310                cdb[0] = MODE_SELECT;
 311                cdb[4] = data_size;
 312        }
 313
 314        return data_size;
 315}
 316
 317static void release_controller(struct kref *kref)
 318{
 319        struct rdac_controller *ctlr;
 320        ctlr = container_of(kref, struct rdac_controller, kref);
 321
 322        list_del(&ctlr->node);
 323        kfree(ctlr);
 324}
 325
 326static struct rdac_controller *get_controller(int index, char *array_name,
 327                        u8 *array_id, struct scsi_device *sdev)
 328{
 329        struct rdac_controller *ctlr, *tmp;
 330
 331        list_for_each_entry(tmp, &ctlr_list, node) {
 332                if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
 333                          (tmp->index == index) &&
 334                          (tmp->host == sdev->host)) {
 335                        kref_get(&tmp->kref);
 336                        return tmp;
 337                }
 338        }
 339        ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
 340        if (!ctlr)
 341                return NULL;
 342
 343        /* initialize fields of controller */
 344        memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
 345        ctlr->index = index;
 346        ctlr->host = sdev->host;
 347        memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
 348
 349        kref_init(&ctlr->kref);
 350        ctlr->use_ms10 = -1;
 351        ctlr->ms_queued = 0;
 352        ctlr->ms_sdev = NULL;
 353        spin_lock_init(&ctlr->ms_lock);
 354        INIT_WORK(&ctlr->ms_work, send_mode_select);
 355        INIT_LIST_HEAD(&ctlr->ms_head);
 356        list_add(&ctlr->node, &ctlr_list);
 357        INIT_LIST_HEAD(&ctlr->dh_list);
 358
 359        return ctlr;
 360}
 361
 362static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
 363                        char *array_name, u8 *array_id)
 364{
 365        int err = SCSI_DH_IO, i;
 366        struct c8_inquiry *inqp = &h->inq.c8;
 367
 368        if (!scsi_get_vpd_page(sdev, 0xC8, (unsigned char *)inqp,
 369                               sizeof(struct c8_inquiry))) {
 370                if (inqp->page_code != 0xc8)
 371                        return SCSI_DH_NOSYS;
 372                if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
 373                    inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
 374                        return SCSI_DH_NOSYS;
 375                h->lun = inqp->lun[7]; /* Uses only the last byte */
 376
 377                for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
 378                        *(array_name+i) = inqp->array_user_label[(2*i)+1];
 379
 380                *(array_name+ARRAY_LABEL_LEN-1) = '\0';
 381                memset(array_id, 0, UNIQUE_ID_LEN);
 382                memcpy(array_id, inqp->array_unique_id, inqp->array_uniq_id_len);
 383                err = SCSI_DH_OK;
 384        }
 385        return err;
 386}
 387
 388static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
 389{
 390        int err = SCSI_DH_IO, access_state;
 391        struct rdac_dh_data *tmp;
 392        struct c9_inquiry *inqp = &h->inq.c9;
 393
 394        h->state = RDAC_STATE_ACTIVE;
 395        if (!scsi_get_vpd_page(sdev, 0xC9, (unsigned char *)inqp,
 396                               sizeof(struct c9_inquiry))) {
 397                /* detect the operating mode */
 398                if ((inqp->avte_cvp >> 5) & 0x1)
 399                        h->mode = RDAC_MODE_IOSHIP; /* LUN in IOSHIP mode */
 400                else if (inqp->avte_cvp >> 7)
 401                        h->mode = RDAC_MODE_AVT; /* LUN in AVT mode */
 402                else
 403                        h->mode = RDAC_MODE; /* LUN in RDAC mode */
 404
 405                /* Update ownership */
 406                if (inqp->avte_cvp & 0x1) {
 407                        h->lun_state = RDAC_LUN_OWNED;
 408                        access_state = SCSI_ACCESS_STATE_OPTIMAL;
 409                } else {
 410                        h->lun_state = RDAC_LUN_UNOWNED;
 411                        if (h->mode == RDAC_MODE) {
 412                                h->state = RDAC_STATE_PASSIVE;
 413                                access_state = SCSI_ACCESS_STATE_STANDBY;
 414                        } else
 415                                access_state = SCSI_ACCESS_STATE_ACTIVE;
 416                }
 417
 418                /* Update path prio*/
 419                if (inqp->path_prio & 0x1) {
 420                        h->preferred = RDAC_PREFERRED;
 421                        access_state |= SCSI_ACCESS_STATE_PREFERRED;
 422                } else
 423                        h->preferred = RDAC_NON_PREFERRED;
 424                rcu_read_lock();
 425                list_for_each_entry_rcu(tmp, &h->ctlr->dh_list, node) {
 426                        /* h->sdev should always be valid */
 427                        BUG_ON(!tmp->sdev);
 428                        tmp->sdev->access_state = access_state;
 429                }
 430                rcu_read_unlock();
 431                err = SCSI_DH_OK;
 432        }
 433
 434        return err;
 435}
 436
 437static int initialize_controller(struct scsi_device *sdev,
 438                struct rdac_dh_data *h, char *array_name, u8 *array_id)
 439{
 440        int err = SCSI_DH_IO, index;
 441        struct c4_inquiry *inqp = &h->inq.c4;
 442
 443        if (!scsi_get_vpd_page(sdev, 0xC4, (unsigned char *)inqp,
 444                               sizeof(struct c4_inquiry))) {
 445                /* get the controller index */
 446                if (inqp->slot_id[1] == 0x31)
 447                        index = 0;
 448                else
 449                        index = 1;
 450
 451                spin_lock(&list_lock);
 452                h->ctlr = get_controller(index, array_name, array_id, sdev);
 453                if (!h->ctlr)
 454                        err = SCSI_DH_RES_TEMP_UNAVAIL;
 455                else {
 456                        list_add_rcu(&h->node, &h->ctlr->dh_list);
 457                        h->sdev = sdev;
 458                }
 459                spin_unlock(&list_lock);
 460                err = SCSI_DH_OK;
 461        }
 462        return err;
 463}
 464
 465static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
 466{
 467        int err = SCSI_DH_IO;
 468        struct c2_inquiry *inqp = &h->inq.c2;
 469
 470        if (!scsi_get_vpd_page(sdev, 0xC2, (unsigned char *)inqp,
 471                               sizeof(struct c2_inquiry))) {
 472                /*
 473                 * If more than MODE6_MAX_LUN luns are supported, use
 474                 * mode select 10
 475                 */
 476                if (inqp->max_lun_supported >= MODE6_MAX_LUN)
 477                        h->ctlr->use_ms10 = 1;
 478                else
 479                        h->ctlr->use_ms10 = 0;
 480                err = SCSI_DH_OK;
 481        }
 482        return err;
 483}
 484
 485static int mode_select_handle_sense(struct scsi_device *sdev,
 486                                    struct scsi_sense_hdr *sense_hdr)
 487{
 488        int err = SCSI_DH_IO;
 489        struct rdac_dh_data *h = sdev->handler_data;
 490
 491        if (!scsi_sense_valid(sense_hdr))
 492                goto done;
 493
 494        switch (sense_hdr->sense_key) {
 495        case NO_SENSE:
 496        case ABORTED_COMMAND:
 497        case UNIT_ATTENTION:
 498                err = SCSI_DH_RETRY;
 499                break;
 500        case NOT_READY:
 501                if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
 502                        /* LUN Not Ready and is in the Process of Becoming
 503                         * Ready
 504                         */
 505                        err = SCSI_DH_RETRY;
 506                break;
 507        case ILLEGAL_REQUEST:
 508                if (sense_hdr->asc == 0x91 && sense_hdr->ascq == 0x36)
 509                        /*
 510                         * Command Lock contention
 511                         */
 512                        err = SCSI_DH_IMM_RETRY;
 513                break;
 514        default:
 515                break;
 516        }
 517
 518        RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 519                "MODE_SELECT returned with sense %02x/%02x/%02x",
 520                (char *) h->ctlr->array_name, h->ctlr->index,
 521                sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 522
 523done:
 524        return err;
 525}
 526
 527static void send_mode_select(struct work_struct *work)
 528{
 529        struct rdac_controller *ctlr =
 530                container_of(work, struct rdac_controller, ms_work);
 531        struct scsi_device *sdev = ctlr->ms_sdev;
 532        struct rdac_dh_data *h = sdev->handler_data;
 533        int err = SCSI_DH_OK, retry_cnt = RDAC_RETRY_COUNT;
 534        struct rdac_queue_data *tmp, *qdata;
 535        LIST_HEAD(list);
 536        unsigned char cdb[MAX_COMMAND_SIZE];
 537        struct scsi_sense_hdr sshdr;
 538        unsigned int data_size;
 539        u64 req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 540                REQ_FAILFAST_DRIVER;
 541
 542        spin_lock(&ctlr->ms_lock);
 543        list_splice_init(&ctlr->ms_head, &list);
 544        ctlr->ms_queued = 0;
 545        ctlr->ms_sdev = NULL;
 546        spin_unlock(&ctlr->ms_lock);
 547
 548 retry:
 549        memset(cdb, 0, sizeof(cdb));
 550
 551        data_size = rdac_failover_get(ctlr, &list, cdb);
 552
 553        RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 554                "%s MODE_SELECT command",
 555                (char *) h->ctlr->array_name, h->ctlr->index,
 556                (retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
 557
 558        if (scsi_execute(sdev, cdb, DMA_TO_DEVICE, &h->ctlr->mode_select,
 559                        data_size, NULL, &sshdr, RDAC_TIMEOUT * HZ,
 560                        RDAC_RETRIES, req_flags, 0, NULL)) {
 561                err = mode_select_handle_sense(sdev, &sshdr);
 562                if (err == SCSI_DH_RETRY && retry_cnt--)
 563                        goto retry;
 564                if (err == SCSI_DH_IMM_RETRY)
 565                        goto retry;
 566        }
 567        if (err == SCSI_DH_OK) {
 568                h->state = RDAC_STATE_ACTIVE;
 569                RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 570                                "MODE_SELECT completed",
 571                                (char *) h->ctlr->array_name, h->ctlr->index);
 572        }
 573
 574        list_for_each_entry_safe(qdata, tmp, &list, entry) {
 575                list_del(&qdata->entry);
 576                if (err == SCSI_DH_OK)
 577                        qdata->h->state = RDAC_STATE_ACTIVE;
 578                if (qdata->callback_fn)
 579                        qdata->callback_fn(qdata->callback_data, err);
 580                kfree(qdata);
 581        }
 582        return;
 583}
 584
 585static int queue_mode_select(struct scsi_device *sdev,
 586                                activate_complete fn, void *data)
 587{
 588        struct rdac_queue_data *qdata;
 589        struct rdac_controller *ctlr;
 590
 591        qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
 592        if (!qdata)
 593                return SCSI_DH_RETRY;
 594
 595        qdata->h = sdev->handler_data;
 596        qdata->callback_fn = fn;
 597        qdata->callback_data = data;
 598
 599        ctlr = qdata->h->ctlr;
 600        spin_lock(&ctlr->ms_lock);
 601        list_add_tail(&qdata->entry, &ctlr->ms_head);
 602        if (!ctlr->ms_queued) {
 603                ctlr->ms_queued = 1;
 604                ctlr->ms_sdev = sdev;
 605                queue_work(kmpath_rdacd, &ctlr->ms_work);
 606        }
 607        spin_unlock(&ctlr->ms_lock);
 608        return SCSI_DH_OK;
 609}
 610
 611static int rdac_activate(struct scsi_device *sdev,
 612                        activate_complete fn, void *data)
 613{
 614        struct rdac_dh_data *h = sdev->handler_data;
 615        int err = SCSI_DH_OK;
 616        int act = 0;
 617
 618        err = check_ownership(sdev, h);
 619        if (err != SCSI_DH_OK)
 620                goto done;
 621
 622        switch (h->mode) {
 623        case RDAC_MODE:
 624                if (h->lun_state == RDAC_LUN_UNOWNED)
 625                        act = 1;
 626                break;
 627        case RDAC_MODE_IOSHIP:
 628                if ((h->lun_state == RDAC_LUN_UNOWNED) &&
 629                    (h->preferred == RDAC_PREFERRED))
 630                        act = 1;
 631                break;
 632        default:
 633                break;
 634        }
 635
 636        if (act) {
 637                err = queue_mode_select(sdev, fn, data);
 638                if (err == SCSI_DH_OK)
 639                        return 0;
 640        }
 641done:
 642        if (fn)
 643                fn(data, err);
 644        return 0;
 645}
 646
 647static blk_status_t rdac_prep_fn(struct scsi_device *sdev, struct request *req)
 648{
 649        struct rdac_dh_data *h = sdev->handler_data;
 650
 651        if (h->state != RDAC_STATE_ACTIVE) {
 652                req->rq_flags |= RQF_QUIET;
 653                return BLK_STS_IOERR;
 654        }
 655
 656        return BLK_STS_OK;
 657}
 658
 659static int rdac_check_sense(struct scsi_device *sdev,
 660                                struct scsi_sense_hdr *sense_hdr)
 661{
 662        struct rdac_dh_data *h = sdev->handler_data;
 663
 664        RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
 665                        "I/O returned with sense %02x/%02x/%02x",
 666                        (char *) h->ctlr->array_name, h->ctlr->index,
 667                        sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 668
 669        switch (sense_hdr->sense_key) {
 670        case NOT_READY:
 671                if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
 672                        /* LUN Not Ready - Logical Unit Not Ready and is in
 673                        * the process of becoming ready
 674                        * Just retry.
 675                        */
 676                        return ADD_TO_MLQUEUE;
 677                if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
 678                        /* LUN Not Ready - Storage firmware incompatible
 679                         * Manual code synchonisation required.
 680                         *
 681                         * Nothing we can do here. Try to bypass the path.
 682                         */
 683                        return SUCCESS;
 684                if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
 685                        /* LUN Not Ready - Quiescense in progress
 686                         *
 687                         * Just retry and wait.
 688                         */
 689                        return ADD_TO_MLQUEUE;
 690                if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
 691                        /* LUN Not Ready - Quiescense in progress
 692                         * or has been achieved
 693                         * Just retry.
 694                         */
 695                        return ADD_TO_MLQUEUE;
 696                break;
 697        case ILLEGAL_REQUEST:
 698                if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
 699                        /* Invalid Request - Current Logical Unit Ownership.
 700                         * Controller is not the current owner of the LUN,
 701                         * Fail the path, so that the other path be used.
 702                         */
 703                        h->state = RDAC_STATE_PASSIVE;
 704                        return SUCCESS;
 705                }
 706                break;
 707        case UNIT_ATTENTION:
 708                if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 709                        /*
 710                         * Power On, Reset, or Bus Device Reset, just retry.
 711                         */
 712                        return ADD_TO_MLQUEUE;
 713                if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
 714                        /*
 715                         * Quiescence in progress , just retry.
 716                         */
 717                        return ADD_TO_MLQUEUE;
 718                break;
 719        }
 720        /* success just means we do not care what scsi-ml does */
 721        return SCSI_RETURN_NOT_HANDLED;
 722}
 723
 724static int rdac_bus_attach(struct scsi_device *sdev)
 725{
 726        struct rdac_dh_data *h;
 727        int err;
 728        char array_name[ARRAY_LABEL_LEN];
 729        char array_id[UNIQUE_ID_LEN];
 730
 731        h = kzalloc(sizeof(*h) , GFP_KERNEL);
 732        if (!h)
 733                return SCSI_DH_NOMEM;
 734        h->lun = UNINITIALIZED_LUN;
 735        h->state = RDAC_STATE_ACTIVE;
 736
 737        err = get_lun_info(sdev, h, array_name, array_id);
 738        if (err != SCSI_DH_OK)
 739                goto failed;
 740
 741        err = initialize_controller(sdev, h, array_name, array_id);
 742        if (err != SCSI_DH_OK)
 743                goto failed;
 744
 745        err = check_ownership(sdev, h);
 746        if (err != SCSI_DH_OK)
 747                goto clean_ctlr;
 748
 749        err = set_mode_select(sdev, h);
 750        if (err != SCSI_DH_OK)
 751                goto clean_ctlr;
 752
 753        sdev_printk(KERN_NOTICE, sdev,
 754                    "%s: LUN %d (%s) (%s)\n",
 755                    RDAC_NAME, h->lun, mode[(int)h->mode],
 756                    lun_state[(int)h->lun_state]);
 757
 758        sdev->handler_data = h;
 759        return SCSI_DH_OK;
 760
 761clean_ctlr:
 762        spin_lock(&list_lock);
 763        kref_put(&h->ctlr->kref, release_controller);
 764        spin_unlock(&list_lock);
 765
 766failed:
 767        kfree(h);
 768        return err;
 769}
 770
 771static void rdac_bus_detach( struct scsi_device *sdev )
 772{
 773        struct rdac_dh_data *h = sdev->handler_data;
 774
 775        if (h->ctlr && h->ctlr->ms_queued)
 776                flush_workqueue(kmpath_rdacd);
 777
 778        spin_lock(&list_lock);
 779        if (h->ctlr) {
 780                list_del_rcu(&h->node);
 781                h->sdev = NULL;
 782                kref_put(&h->ctlr->kref, release_controller);
 783        }
 784        spin_unlock(&list_lock);
 785        sdev->handler_data = NULL;
 786        kfree(h);
 787}
 788
 789static struct scsi_device_handler rdac_dh = {
 790        .name = RDAC_NAME,
 791        .module = THIS_MODULE,
 792        .prep_fn = rdac_prep_fn,
 793        .check_sense = rdac_check_sense,
 794        .attach = rdac_bus_attach,
 795        .detach = rdac_bus_detach,
 796        .activate = rdac_activate,
 797};
 798
 799static int __init rdac_init(void)
 800{
 801        int r;
 802
 803        r = scsi_register_device_handler(&rdac_dh);
 804        if (r != 0) {
 805                printk(KERN_ERR "Failed to register scsi device handler.");
 806                goto done;
 807        }
 808
 809        /*
 810         * Create workqueue to handle mode selects for rdac
 811         */
 812        kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
 813        if (!kmpath_rdacd) {
 814                scsi_unregister_device_handler(&rdac_dh);
 815                printk(KERN_ERR "kmpath_rdacd creation failed.\n");
 816
 817                r = -EINVAL;
 818        }
 819done:
 820        return r;
 821}
 822
 823static void __exit rdac_exit(void)
 824{
 825        destroy_workqueue(kmpath_rdacd);
 826        scsi_unregister_device_handler(&rdac_dh);
 827}
 828
 829module_init(rdac_init);
 830module_exit(rdac_exit);
 831
 832MODULE_DESCRIPTION("Multipath LSI/Engenio/NetApp E-Series RDAC driver");
 833MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
 834MODULE_VERSION("01.00.0000.0000");
 835MODULE_LICENSE("GPL");
 836