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         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
 216 static const char *mode[] = {
 217         "RDAC",
 218         "AVT",
 219         "IOSHIP",
 220 };
 221 static const char *lun_state[] =
 222 {
 223         "unowned",
 224         "owned",
 225 };
 226
 227 struct 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
 234 static LIST_HEAD(ctlr_list);
 235 static DEFINE_SPINLOCK(list_lock);
 236 static struct workqueue_struct *kmpath_rdacd;
 237 static 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  */
 244 static int rdac_logging = 1;
 245 module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
 246 MODULE_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...) \
 259 do { \
 260         if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
 261                 sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
 262 } while (0);
 263
 264 static 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
 317 static 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
 326 static 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
 362 static 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
 388 static 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
 437 static 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
 465 static 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
 485 static 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
 523 done:
 524         return err;
 525 }
 526
 527 static 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         data_size = rdac_failover_get(ctlr, &list, cdb);
 550
 551         RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 552                 "%s MODE_SELECT command",
 553                 (char *) h->ctlr->array_name, h->ctlr->index,
 554                 (retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
 555
 556         if (scsi_execute(sdev, cdb, DMA_TO_DEVICE, &h->ctlr->mode_select,
 557                         data_size, NULL, &sshdr, RDAC_TIMEOUT * HZ,
 558                         RDAC_RETRIES, req_flags, 0, NULL)) {
 559                 err = mode_select_handle_sense(sdev, &sshdr);
 560                 if (err == SCSI_DH_RETRY && retry_cnt--)
 561                         goto retry;
 562                 if (err == SCSI_DH_IMM_RETRY)
 563                         goto retry;
 564         }
 565         if (err == SCSI_DH_OK) {
 566                 h->state = RDAC_STATE_ACTIVE;
 567                 RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 568                                 "MODE_SELECT completed",
 569                                 (char *) h->ctlr->array_name, h->ctlr->index);
 570         }
 571
 572         list_for_each_entry_safe(qdata, tmp, &list, entry) {
 573                 list_del(&qdata->entry);
 574                 if (err == SCSI_DH_OK)
 575                         qdata->h->state = RDAC_STATE_ACTIVE;
 576                 if (qdata->callback_fn)
 577                         qdata->callback_fn(qdata->callback_data, err);
 578                 kfree(qdata);
 579         }
 580         return;
 581 }
 582
 583 static int queue_mode_select(struct scsi_device *sdev,
 584                                 activate_complete fn, void *data)
 585 {
 586         struct rdac_queue_data *qdata;
 587         struct rdac_controller *ctlr;
 588
 589         qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
 590         if (!qdata)
 591                 return SCSI_DH_RETRY;
 592
 593         qdata->h = sdev->handler_data;
 594         qdata->callback_fn = fn;
 595         qdata->callback_data = data;
 596
 597         ctlr = qdata->h->ctlr;
 598         spin_lock(&ctlr->ms_lock);
 599         list_add_tail(&qdata->entry, &ctlr->ms_head);
 600         if (!ctlr->ms_queued) {
 601                 ctlr->ms_queued = 1;
 602                 ctlr->ms_sdev = sdev;
 603                 queue_work(kmpath_rdacd, &ctlr->ms_work);
 604         }
 605         spin_unlock(&ctlr->ms_lock);
 606         return SCSI_DH_OK;
 607 }
 608
 609 static int rdac_activate(struct scsi_device *sdev,
 610                         activate_complete fn, void *data)
 611 {
 612         struct rdac_dh_data *h = sdev->handler_data;
 613         int err = SCSI_DH_OK;
 614         int act = 0;
 615
 616         err = check_ownership(sdev, h);
 617         if (err != SCSI_DH_OK)
 618                 goto done;
 619
 620         switch (h->mode) {
 621         case RDAC_MODE:
 622                 if (h->lun_state == RDAC_LUN_UNOWNED)
 623                         act = 1;
 624                 break;
 625         case RDAC_MODE_IOSHIP:
 626                 if ((h->lun_state == RDAC_LUN_UNOWNED) &&
 627                     (h->preferred == RDAC_PREFERRED))
 628                         act = 1;
 629                 break;
 630         default:
 631                 break;
 632         }
 633
 634         if (act) {
 635                 err = queue_mode_select(sdev, fn, data);
 636                 if (err == SCSI_DH_OK)
 637                         return 0;
 638         }
 639 done:
 640         if (fn)
 641                 fn(data, err);
 642         return 0;
 643 }
 644
 645 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
 646 {
 647         struct rdac_dh_data *h = sdev->handler_data;
 648         int ret = BLKPREP_OK;
 649
 650         if (h->state != RDAC_STATE_ACTIVE) {
 651                 ret = BLKPREP_KILL;
 652                 req->rq_flags |= RQF_QUIET;
 653         }
 654         return ret;
 655
 656 }
 657
 658 static int rdac_check_sense(struct scsi_device *sdev,
 659                                 struct scsi_sense_hdr *sense_hdr)
 660 {
 661         struct rdac_dh_data *h = sdev->handler_data;
 662
 663         RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
 664                         "I/O returned with sense %02x/%02x/%02x",
 665                         (char *) h->ctlr->array_name, h->ctlr->index,
 666                         sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 667
 668         switch (sense_hdr->sense_key) {
 669         case NOT_READY:
 670                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
 671                         /* LUN Not Ready - Logical Unit Not Ready and is in
 672                         * the process of becoming ready
 673                         * Just retry.
 674                         */
 675                         return ADD_TO_MLQUEUE;
 676                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
 677                         /* LUN Not Ready - Storage firmware incompatible
 678                          * Manual code synchonisation required.
 679                          *
 680                          * Nothing we can do here. Try to bypass the path.
 681                          */
 682                         return SUCCESS;
 683                 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
 684                         /* LUN Not Ready - Quiescense in progress
 685                          *
 686                          * Just retry and wait.
 687                          */
 688                         return ADD_TO_MLQUEUE;
 689                 if (sense_hdr->asc == 0xA1  && sense_hdr->ascq == 0x02)
 690                         /* LUN Not Ready - Quiescense in progress
 691                          * or has been achieved
 692                          * Just retry.
 693                          */
 694                         return ADD_TO_MLQUEUE;
 695                 break;
 696         case ILLEGAL_REQUEST:
 697                 if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
 698                         /* Invalid Request - Current Logical Unit Ownership.
 699                          * Controller is not the current owner of the LUN,
 700                          * Fail the path, so that the other path be used.
 701                          */
 702                         h->state = RDAC_STATE_PASSIVE;
 703                         return SUCCESS;
 704                 }
 705                 break;
 706         case UNIT_ATTENTION:
 707                 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
 708                         /*
 709                          * Power On, Reset, or Bus Device Reset, just retry.
 710                          */
 711                         return ADD_TO_MLQUEUE;
 712                 if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
 713                         /*
 714                          * Quiescence in progress , just retry.
 715                          */
 716                         return ADD_TO_MLQUEUE;
 717                 break;
 718         }
 719         /* success just means we do not care what scsi-ml does */
 720         return SCSI_RETURN_NOT_HANDLED;
 721 }
 722
 723 static int rdac_bus_attach(struct scsi_device *sdev)
 724 {
 725         struct rdac_dh_data *h;
 726         int err;
 727         char array_name[ARRAY_LABEL_LEN];
 728         char array_id[UNIQUE_ID_LEN];
 729
 730         h = kzalloc(sizeof(*h) , GFP_KERNEL);
 731         if (!h)
 732                 return SCSI_DH_NOMEM;
 733         h->lun = UNINITIALIZED_LUN;
 734         h->state = RDAC_STATE_ACTIVE;
 735
 736         err = get_lun_info(sdev, h, array_name, array_id);
 737         if (err != SCSI_DH_OK)
 738                 goto failed;
 739
 740         err = initialize_controller(sdev, h, array_name, array_id);
 741         if (err != SCSI_DH_OK)
 742                 goto failed;
 743
 744         err = check_ownership(sdev, h);
 745         if (err != SCSI_DH_OK)
 746                 goto clean_ctlr;
 747
 748         err = set_mode_select(sdev, h);
 749         if (err != SCSI_DH_OK)
 750                 goto clean_ctlr;
 751
 752         sdev_printk(KERN_NOTICE, sdev,
 753                     "%s: LUN %d (%s) (%s)\n",
 754                     RDAC_NAME, h->lun, mode[(int)h->mode],
 755                     lun_state[(int)h->lun_state]);
 756
 757         sdev->handler_data = h;
 758         return SCSI_DH_OK;
 759
 760 clean_ctlr:
 761         spin_lock(&list_lock);
 762         kref_put(&h->ctlr->kref, release_controller);
 763         spin_unlock(&list_lock);
 764
 765 failed:
 766         kfree(h);
 767         return err;
 768 }
 769
 770 static void rdac_bus_detach( struct scsi_device *sdev )
 771 {
 772         struct rdac_dh_data *h = sdev->handler_data;
 773
 774         if (h->ctlr && h->ctlr->ms_queued)
 775                 flush_workqueue(kmpath_rdacd);
 776
 777         spin_lock(&list_lock);
 778         if (h->ctlr) {
 779                 list_del_rcu(&h->node);
 780                 h->sdev = NULL;
 781                 kref_put(&h->ctlr->kref, release_controller);
 782         }
 783         spin_unlock(&list_lock);
 784         sdev->handler_data = NULL;
 785         kfree(h);
 786 }
 787
 788 static struct scsi_device_handler rdac_dh = {
 789         .name = RDAC_NAME,
 790         .module = THIS_MODULE,
 791         .prep_fn = rdac_prep_fn,
 792         .check_sense = rdac_check_sense,
 793         .attach = rdac_bus_attach,
 794         .detach = rdac_bus_detach,
 795         .activate = rdac_activate,
 796 };
 797
 798 static int __init rdac_init(void)
 799 {
 800         int r;
 801
 802         r = scsi_register_device_handler(&rdac_dh);
 803         if (r != 0) {
 804                 printk(KERN_ERR "Failed to register scsi device handler.");
 805                 goto done;
 806         }
 807
 808         /*
 809          * Create workqueue to handle mode selects for rdac
 810          */
 811         kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
 812         if (!kmpath_rdacd) {
 813                 scsi_unregister_device_handler(&rdac_dh);
 814                 printk(KERN_ERR "kmpath_rdacd creation failed.\n");
 815
 816                 r = -EINVAL;
 817         }
 818 done:
 819         return r;
 820 }
 821
 822 static void __exit rdac_exit(void)
 823 {
 824         destroy_workqueue(kmpath_rdacd);
 825         scsi_unregister_device_handler(&rdac_dh);
 826 }
 827
 828 module_init(rdac_init);
 829 module_exit(rdac_exit);
 830
 831 MODULE_DESCRIPTION("Multipath LSI/Engenio/NetApp E-Series RDAC driver");
 832 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
 833 MODULE_VERSION("01.00.0000.0000");
 834 MODULE_LICENSE("GPL");