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        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
 217static const char *mode[] = {
 218        "RDAC",
 219        "AVT",
 220        "IOSHIP",
 221};
 222static const char *lun_state[] =
 223{
 224        "unowned",
 225        "owned",
 226};
 227
 228struct 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
 235static LIST_HEAD(ctlr_list);
 236static DEFINE_SPINLOCK(list_lock);
 237static struct workqueue_struct *kmpath_rdacd;
 238static 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 */
 245static int rdac_logging = 1;
 246module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
 247MODULE_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...) \
 260do { \
 261        if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
 262                sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
 263} while (0);
 264
 265static 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
 295static 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
 358static 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
 367static 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
 403static 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);
 430done:
 431        return err;
 432}
 433
 434static 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
 460static 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
 509static 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
 537static 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
 557static 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
 597done:
 598        return err;
 599}
 600
 601static 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
 619retry:
 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
 646done:
 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
 658static 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
 684static 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        }
 714done:
 715        if (fn)
 716                fn(data, err);
 717        return 0;
 718}
 719
 720static 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
 733static 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
 798static 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
 835clean_ctlr:
 836        spin_lock(&list_lock);
 837        kref_put(&h->ctlr->kref, release_controller);
 838        spin_unlock(&list_lock);
 839
 840failed:
 841        kfree(h);
 842        return -EINVAL;
 843}
 844
 845static 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
 863static 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
 873static 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        }
 893done:
 894        return r;
 895}
 896
 897static void __exit rdac_exit(void)
 898{
 899        destroy_workqueue(kmpath_rdacd);
 900        scsi_unregister_device_handler(&rdac_dh);
 901}
 902
 903module_init(rdac_init);
 904module_exit(rdac_exit);
 905
 906MODULE_DESCRIPTION("Multipath LSI/Engenio/NetApp E-Series RDAC driver");
 907MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
 908MODULE_VERSION("01.00.0000.0000");
 909MODULE_LICENSE("GPL");
 910