drivers/scsi/scsi_sysfs.c

   1 /*
   2  * scsi_sysfs.c
   3  *
   4  * SCSI sysfs interface routines.
   5  *
   6  * Created to pull SCSI mid layer sysfs routines into one file.
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/init.h>
  11 #include <linux/blkdev.h>
  12 #include <linux/device.h>
  13
  14 #include <scsi/scsi.h>
  15 #include <scsi/scsi_device.h>
  16 #include <scsi/scsi_host.h>
  17 #include <scsi/scsi_tcq.h>
  18 #include <scsi/scsi_transport.h>
  19
  20 #include "scsi_priv.h"
  21 #include "scsi_logging.h"
  22
  23 static const struct {
  24         enum scsi_device_state  value;
  25         char                    *name;
  26 } sdev_states[] = {
  27         { SDEV_CREATED, "created" },
  28         { SDEV_RUNNING, "running" },
  29         { SDEV_CANCEL, "cancel" },
  30         { SDEV_DEL, "deleted" },
  31         { SDEV_QUIESCE, "quiesce" },
  32         { SDEV_OFFLINE, "offline" },
  33         { SDEV_BLOCK,   "blocked" },
  34 };
  35
  36 const char *scsi_device_state_name(enum scsi_device_state state)
  37 {
  38         int i;
  39         char *name = NULL;
  40
  41         for (i = 0; i < ARRAY_SIZE(sdev_states); i++) {
  42                 if (sdev_states[i].value == state) {
  43                         name = sdev_states[i].name;
  44                         break;
  45                 }
  46         }
  47         return name;
  48 }
  49
  50 static const struct {
  51         enum scsi_host_state    value;
  52         char                    *name;
  53 } shost_states[] = {
  54         { SHOST_CREATED, "created" },
  55         { SHOST_RUNNING, "running" },
  56         { SHOST_CANCEL, "cancel" },
  57         { SHOST_DEL, "deleted" },
  58         { SHOST_RECOVERY, "recovery" },
  59         { SHOST_CANCEL_RECOVERY, "cancel/recovery" },
  60         { SHOST_DEL_RECOVERY, "deleted/recovery", },
  61 };
  62 const char *scsi_host_state_name(enum scsi_host_state state)
  63 {
  64         int i;
  65         char *name = NULL;
  66
  67         for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
  68                 if (shost_states[i].value == state) {
  69                         name = shost_states[i].name;
  70                         break;
  71                 }
  72         }
  73         return name;
  74 }
  75
  76 static int check_set(unsigned int *val, char *src)
  77 {
  78         char *last;
  79
  80         if (strncmp(src, "-", 20) == 0) {
  81                 *val = SCAN_WILD_CARD;
  82         } else {
  83                 /*
  84                  * Doesn't check for int overflow
  85                  */
  86                 *val = simple_strtoul(src, &last, 0);
  87                 if (*last != '\0')
  88                         return 1;
  89         }
  90         return 0;
  91 }
  92
  93 static int scsi_scan(struct Scsi_Host *shost, const char *str)
  94 {
  95         char s1[15], s2[15], s3[15], junk;
  96         unsigned int channel, id, lun;
  97         int res;
  98
  99         res = sscanf(str, "%10s %10s %10s %c", s1, s2, s3, &junk);
 100         if (res != 3)
 101                 return -EINVAL;
 102         if (check_set(&channel, s1))
 103                 return -EINVAL;
 104         if (check_set(&id, s2))
 105                 return -EINVAL;
 106         if (check_set(&lun, s3))
 107                 return -EINVAL;
 108         if (shost->transportt->user_scan)
 109                 res = shost->transportt->user_scan(shost, channel, id, lun);
 110         else
 111                 res = scsi_scan_host_selected(shost, channel, id, lun, 1);
 112         return res;
 113 }
 114
 115 /*
 116  * shost_show_function: macro to create an attr function that can be used to
 117  * show a non-bit field.
 118  */
 119 #define shost_show_function(name, field, format_string)                 \
 120 static ssize_t                                                          \
 121 show_##name (struct class_device *class_dev, char *buf)                 \
 122 {                                                                       \
 123         struct Scsi_Host *shost = class_to_shost(class_dev);            \
 124         return snprintf (buf, 20, format_string, shost->field);         \
 125 }
 126
 127 /*
 128  * shost_rd_attr: macro to create a function and attribute variable for a
 129  * read only field.
 130  */
 131 #define shost_rd_attr2(name, field, format_string)                      \
 132         shost_show_function(name, field, format_string)                 \
 133 static CLASS_DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);
 134
 135 #define shost_rd_attr(field, format_string) \
 136 shost_rd_attr2(field, field, format_string)
 137
 138 /*
 139  * Create the actual show/store functions and data structures.
 140  */
 141
 142 static ssize_t store_scan(struct class_device *class_dev, const char *buf,
 143                           size_t count)
 144 {
 145         struct Scsi_Host *shost = class_to_shost(class_dev);
 146         int res;
 147
 148         res = scsi_scan(shost, buf);
 149         if (res == 0)
 150                 res = count;
 151         return res;
 152 };
 153 static CLASS_DEVICE_ATTR(scan, S_IWUSR, NULL, store_scan);
 154
 155 static ssize_t
 156 store_shost_state(struct class_device *class_dev, const char *buf, size_t count)
 157 {
 158         int i;
 159         struct Scsi_Host *shost = class_to_shost(class_dev);
 160         enum scsi_host_state state = 0;
 161
 162         for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
 163                 const int len = strlen(shost_states[i].name);
 164                 if (strncmp(shost_states[i].name, buf, len) == 0 &&
 165                    buf[len] == '\n') {
 166                         state = shost_states[i].value;
 167                         break;
 168                 }
 169         }
 170         if (!state)
 171                 return -EINVAL;
 172
 173         if (scsi_host_set_state(shost, state))
 174                 return -EINVAL;
 175         return count;
 176 }
 177
 178 static ssize_t
 179 show_shost_state(struct class_device *class_dev, char *buf)
 180 {
 181         struct Scsi_Host *shost = class_to_shost(class_dev);
 182         const char *name = scsi_host_state_name(shost->shost_state);
 183
 184         if (!name)
 185                 return -EINVAL;
 186
 187         return snprintf(buf, 20, "%s\n", name);
 188 }
 189
 190 static CLASS_DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_shost_state, store_shost_state);
 191
 192 shost_rd_attr(unique_id, "%u\n");
 193 shost_rd_attr(host_busy, "%hu\n");
 194 shost_rd_attr(cmd_per_lun, "%hd\n");
 195 shost_rd_attr(can_queue, "%hd\n");
 196 shost_rd_attr(sg_tablesize, "%hu\n");
 197 shost_rd_attr(unchecked_isa_dma, "%d\n");
 198 shost_rd_attr2(proc_name, hostt->proc_name, "%s\n");
 199
 200 static struct class_device_attribute *scsi_sysfs_shost_attrs[] = {
 201         &class_device_attr_unique_id,
 202         &class_device_attr_host_busy,
 203         &class_device_attr_cmd_per_lun,
 204         &class_device_attr_can_queue,
 205         &class_device_attr_sg_tablesize,
 206         &class_device_attr_unchecked_isa_dma,
 207         &class_device_attr_proc_name,
 208         &class_device_attr_scan,
 209         &class_device_attr_state,
 210         NULL
 211 };
 212
 213 static void scsi_device_cls_release(struct class_device *class_dev)
 214 {
 215         struct scsi_device *sdev;
 216
 217         sdev = class_to_sdev(class_dev);
 218         put_device(&sdev->sdev_gendev);
 219 }
 220
 221 static void scsi_device_dev_release_usercontext(struct work_struct *work)
 222 {
 223         struct scsi_device *sdev;
 224         struct device *parent;
 225         struct scsi_target *starget;
 226         unsigned long flags;
 227
 228         sdev = container_of(work, struct scsi_device, ew.work);
 229
 230         parent = sdev->sdev_gendev.parent;
 231         starget = to_scsi_target(parent);
 232
 233         spin_lock_irqsave(sdev->host->host_lock, flags);
 234         starget->reap_ref++;
 235         list_del(&sdev->siblings);
 236         list_del(&sdev->same_target_siblings);
 237         list_del(&sdev->starved_entry);
 238         spin_unlock_irqrestore(sdev->host->host_lock, flags);
 239
 240         if (sdev->request_queue) {
 241                 sdev->request_queue->queuedata = NULL;
 242                 /* user context needed to free queue */
 243                 scsi_free_queue(sdev->request_queue);
 244                 /* temporary expedient, try to catch use of queue lock
 245                  * after free of sdev */
 246                 sdev->request_queue = NULL;
 247         }
 248
 249         scsi_target_reap(scsi_target(sdev));
 250
 251         kfree(sdev->inquiry);
 252         kfree(sdev);
 253
 254         if (parent)
 255                 put_device(parent);
 256 }
 257
 258 static void scsi_device_dev_release(struct device *dev)
 259 {
 260         struct scsi_device *sdp = to_scsi_device(dev);
 261         execute_in_process_context(scsi_device_dev_release_usercontext,
 262                                    &sdp->ew);
 263 }
 264
 265 static struct class sdev_class = {
 266         .name           = "scsi_device",
 267         .release        = scsi_device_cls_release,
 268 };
 269
 270 /* all probing is done in the individual ->probe routines */
 271 static int scsi_bus_match(struct device *dev, struct device_driver *gendrv)
 272 {
 273         struct scsi_device *sdp = to_scsi_device(dev);
 274         if (sdp->no_uld_attach)
 275                 return 0;
 276         return (sdp->inq_periph_qual == SCSI_INQ_PQ_CON)? 1: 0;
 277 }
 278
 279 static int scsi_bus_suspend(struct device * dev, pm_message_t state)
 280 {
 281         struct scsi_device *sdev = to_scsi_device(dev);
 282         struct scsi_host_template *sht = sdev->host->hostt;
 283         int err;
 284
 285         err = scsi_device_quiesce(sdev);
 286         if (err)
 287                 return err;
 288
 289         if (sht->suspend)
 290                 err = sht->suspend(sdev, state);
 291
 292         return err;
 293 }
 294
 295 static int scsi_bus_resume(struct device * dev)
 296 {
 297         struct scsi_device *sdev = to_scsi_device(dev);
 298         struct scsi_host_template *sht = sdev->host->hostt;
 299         int err = 0;
 300
 301         if (sht->resume)
 302                 err = sht->resume(sdev);
 303
 304         scsi_device_resume(sdev);
 305         return err;
 306 }
 307
 308 struct bus_type scsi_bus_type = {
 309         .name           = "scsi",
 310         .match          = scsi_bus_match,
 311         .suspend        = scsi_bus_suspend,
 312         .resume         = scsi_bus_resume,
 313 };
 314
 315 int scsi_sysfs_register(void)
 316 {
 317         int error;
 318
 319         error = bus_register(&scsi_bus_type);
 320         if (!error) {
 321                 error = class_register(&sdev_class);
 322                 if (error)
 323                         bus_unregister(&scsi_bus_type);
 324         }
 325
 326         return error;
 327 }
 328
 329 void scsi_sysfs_unregister(void)
 330 {
 331         class_unregister(&sdev_class);
 332         bus_unregister(&scsi_bus_type);
 333 }
 334
 335 /*
 336  * sdev_show_function: macro to create an attr function that can be used to
 337  * show a non-bit field.
 338  */
 339 #define sdev_show_function(field, format_string)                                \
 340 static ssize_t                                                          \
 341 sdev_show_##field (struct device *dev, struct device_attribute *attr, char *buf)                                \
 342 {                                                                       \
 343         struct scsi_device *sdev;                                       \
 344         sdev = to_scsi_device(dev);                                     \
 345         return snprintf (buf, 20, format_string, sdev->field);          \
 346 }                                                                       \
 347
 348 /*
 349  * sdev_rd_attr: macro to create a function and attribute variable for a
 350  * read only field.
 351  */
 352 #define sdev_rd_attr(field, format_string)                              \
 353         sdev_show_function(field, format_string)                        \
 354 static DEVICE_ATTR(field, S_IRUGO, sdev_show_##field, NULL);
 355
 356
 357 /*
 358  * sdev_rd_attr: create a function and attribute variable for a
 359  * read/write field.
 360  */
 361 #define sdev_rw_attr(field, format_string)                              \
 362         sdev_show_function(field, format_string)                                \
 363                                                                         \
 364 static ssize_t                                                          \
 365 sdev_store_##field (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)   \
 366 {                                                                       \
 367         struct scsi_device *sdev;                                       \
 368         sdev = to_scsi_device(dev);                                     \
 369         snscanf (buf, 20, format_string, &sdev->field);                 \
 370         return count;                                                   \
 371 }                                                                       \
 372 static DEVICE_ATTR(field, S_IRUGO | S_IWUSR, sdev_show_##field, sdev_store_##field);
 373
 374 /* Currently we don't export bit fields, but we might in future,
 375  * so leave this code in */
 376 #if 0
 377 /*
 378  * sdev_rd_attr: create a function and attribute variable for a
 379  * read/write bit field.
 380  */
 381 #define sdev_rw_attr_bit(field)                                         \
 382         sdev_show_function(field, "%d\n")                                       \
 383                                                                         \
 384 static ssize_t                                                          \
 385 sdev_store_##field (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)   \
 386 {                                                                       \
 387         int ret;                                                        \
 388         struct scsi_device *sdev;                                       \
 389         ret = scsi_sdev_check_buf_bit(buf);                             \
 390         if (ret >= 0)   {                                               \
 391                 sdev = to_scsi_device(dev);                             \
 392                 sdev->field = ret;                                      \
 393                 ret = count;                                            \
 394         }                                                               \
 395         return ret;                                                     \
 396 }                                                                       \
 397 static DEVICE_ATTR(field, S_IRUGO | S_IWUSR, sdev_show_##field, sdev_store_##field);
 398
 399 /*
 400  * scsi_sdev_check_buf_bit: return 0 if buf is "0", return 1 if buf is "1",
 401  * else return -EINVAL.
 402  */
 403 static int scsi_sdev_check_buf_bit(const char *buf)
 404 {
 405         if ((buf[1] == '\0') || ((buf[1] == '\n') && (buf[2] == '\0'))) {
 406                 if (buf[0] == '1')
 407                         return 1;
 408                 else if (buf[0] == '0')
 409                         return 0;
 410                 else
 411                         return -EINVAL;
 412         } else
 413                 return -EINVAL;
 414 }
 415 #endif
 416 /*
 417  * Create the actual show/store functions and data structures.
 418  */
 419 sdev_rd_attr (device_blocked, "%d\n");
 420 sdev_rd_attr (queue_depth, "%d\n");
 421 sdev_rd_attr (type, "%d\n");
 422 sdev_rd_attr (scsi_level, "%d\n");
 423 sdev_rd_attr (vendor, "%.8s\n");
 424 sdev_rd_attr (model, "%.16s\n");
 425 sdev_rd_attr (rev, "%.4s\n");
 426
 427 static ssize_t
 428 sdev_show_timeout (struct device *dev, struct device_attribute *attr, char *buf)
 429 {
 430         struct scsi_device *sdev;
 431         sdev = to_scsi_device(dev);
 432         return snprintf (buf, 20, "%d\n", sdev->timeout / HZ);
 433 }
 434
 435 static ssize_t
 436 sdev_store_timeout (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 437 {
 438         struct scsi_device *sdev;
 439         int timeout;
 440         sdev = to_scsi_device(dev);
 441         sscanf (buf, "%d\n", &timeout);
 442         sdev->timeout = timeout * HZ;
 443         return count;
 444 }
 445 static DEVICE_ATTR(timeout, S_IRUGO | S_IWUSR, sdev_show_timeout, sdev_store_timeout);
 446
 447 static ssize_t
 448 store_rescan_field (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 449 {
 450         scsi_rescan_device(dev);
 451         return count;
 452 }
 453 static DEVICE_ATTR(rescan, S_IWUSR, NULL, store_rescan_field);
 454
 455 static ssize_t sdev_store_delete(struct device *dev, struct device_attribute *attr, const char *buf,
 456                                  size_t count)
 457 {
 458         scsi_remove_device(to_scsi_device(dev));
 459         return count;
 460 };
 461 static DEVICE_ATTR(delete, S_IWUSR, NULL, sdev_store_delete);
 462
 463 static ssize_t
 464 store_state_field(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 465 {
 466         int i;
 467         struct scsi_device *sdev = to_scsi_device(dev);
 468         enum scsi_device_state state = 0;
 469
 470         for (i = 0; i < ARRAY_SIZE(sdev_states); i++) {
 471                 const int len = strlen(sdev_states[i].name);
 472                 if (strncmp(sdev_states[i].name, buf, len) == 0 &&
 473                    buf[len] == '\n') {
 474                         state = sdev_states[i].value;
 475                         break;
 476                 }
 477         }
 478         if (!state)
 479                 return -EINVAL;
 480
 481         if (scsi_device_set_state(sdev, state))
 482                 return -EINVAL;
 483         return count;
 484 }
 485
 486 static ssize_t
 487 show_state_field(struct device *dev, struct device_attribute *attr, char *buf)
 488 {
 489         struct scsi_device *sdev = to_scsi_device(dev);
 490         const char *name = scsi_device_state_name(sdev->sdev_state);
 491
 492         if (!name)
 493                 return -EINVAL;
 494
 495         return snprintf(buf, 20, "%s\n", name);
 496 }
 497
 498 static DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_state_field, store_state_field);
 499
 500 static ssize_t
 501 show_queue_type_field(struct device *dev, struct device_attribute *attr, char *buf)
 502 {
 503         struct scsi_device *sdev = to_scsi_device(dev);
 504         const char *name = "none";
 505
 506         if (sdev->ordered_tags)
 507                 name = "ordered";
 508         else if (sdev->simple_tags)
 509                 name = "simple";
 510
 511         return snprintf(buf, 20, "%s\n", name);
 512 }
 513
 514 static DEVICE_ATTR(queue_type, S_IRUGO, show_queue_type_field, NULL);
 515
 516 static ssize_t
 517 show_iostat_counterbits(struct device *dev, struct device_attribute *attr, char *buf)
 518 {
 519         return snprintf(buf, 20, "%d\n", (int)sizeof(atomic_t) * 8);
 520 }
 521
 522 static DEVICE_ATTR(iocounterbits, S_IRUGO, show_iostat_counterbits, NULL);
 523
 524 #define show_sdev_iostat(field)                                         \
 525 static ssize_t                                                          \
 526 show_iostat_##field(struct device *dev, struct device_attribute *attr, char *buf)                       \
 527 {                                                                       \
 528         struct scsi_device *sdev = to_scsi_device(dev);                 \
 529         unsigned long long count = atomic_read(&sdev->field);           \
 530         return snprintf(buf, 20, "0x%llx\n", count);                    \
 531 }                                                                       \
 532 static DEVICE_ATTR(field, S_IRUGO, show_iostat_##field, NULL)
 533
 534 show_sdev_iostat(iorequest_cnt);
 535 show_sdev_iostat(iodone_cnt);
 536 show_sdev_iostat(ioerr_cnt);
 537
 538
 539 /* Default template for device attributes.  May NOT be modified */
 540 static struct device_attribute *scsi_sysfs_sdev_attrs[] = {
 541         &dev_attr_device_blocked,
 542         &dev_attr_queue_depth,
 543         &dev_attr_queue_type,
 544         &dev_attr_type,
 545         &dev_attr_scsi_level,
 546         &dev_attr_vendor,
 547         &dev_attr_model,
 548         &dev_attr_rev,
 549         &dev_attr_rescan,
 550         &dev_attr_delete,
 551         &dev_attr_state,
 552         &dev_attr_timeout,
 553         &dev_attr_iocounterbits,
 554         &dev_attr_iorequest_cnt,
 555         &dev_attr_iodone_cnt,
 556         &dev_attr_ioerr_cnt,
 557         NULL
 558 };
 559
 560 static ssize_t sdev_store_queue_depth_rw(struct device *dev, struct device_attribute *attr, const char *buf,
 561                                          size_t count)
 562 {
 563         int depth, retval;
 564         struct scsi_device *sdev = to_scsi_device(dev);
 565         struct scsi_host_template *sht = sdev->host->hostt;
 566
 567         if (!sht->change_queue_depth)
 568                 return -EINVAL;
 569
 570         depth = simple_strtoul(buf, NULL, 0);
 571
 572         if (depth < 1)
 573                 return -EINVAL;
 574
 575         retval = sht->change_queue_depth(sdev, depth);
 576         if (retval < 0)
 577                 return retval;
 578
 579         return count;
 580 }
 581
 582 static struct device_attribute sdev_attr_queue_depth_rw =
 583         __ATTR(queue_depth, S_IRUGO | S_IWUSR, sdev_show_queue_depth,
 584                sdev_store_queue_depth_rw);
 585
 586 static ssize_t sdev_store_queue_type_rw(struct device *dev, struct device_attribute *attr, const char *buf,
 587                                         size_t count)
 588 {
 589         struct scsi_device *sdev = to_scsi_device(dev);
 590         struct scsi_host_template *sht = sdev->host->hostt;
 591         int tag_type = 0, retval;
 592         int prev_tag_type = scsi_get_tag_type(sdev);
 593
 594         if (!sdev->tagged_supported || !sht->change_queue_type)
 595                 return -EINVAL;
 596
 597         if (strncmp(buf, "ordered", 7) == 0)
 598                 tag_type = MSG_ORDERED_TAG;
 599         else if (strncmp(buf, "simple", 6) == 0)
 600                 tag_type = MSG_SIMPLE_TAG;
 601         else if (strncmp(buf, "none", 4) != 0)
 602                 return -EINVAL;
 603
 604         if (tag_type == prev_tag_type)
 605                 return count;
 606
 607         retval = sht->change_queue_type(sdev, tag_type);
 608         if (retval < 0)
 609                 return retval;
 610
 611         return count;
 612 }
 613
 614 static struct device_attribute sdev_attr_queue_type_rw =
 615         __ATTR(queue_type, S_IRUGO | S_IWUSR, show_queue_type_field,
 616                sdev_store_queue_type_rw);
 617
 618 static struct device_attribute *attr_changed_internally(
 619                 struct Scsi_Host *shost,
 620                 struct device_attribute * attr)
 621 {
 622         if (!strcmp("queue_depth", attr->attr.name)
 623             && shost->hostt->change_queue_depth)
 624                 return &sdev_attr_queue_depth_rw;
 625         else if (!strcmp("queue_type", attr->attr.name)
 626             && shost->hostt->change_queue_type)
 627                 return &sdev_attr_queue_type_rw;
 628         return attr;
 629 }
 630
 631
 632 static struct device_attribute *attr_overridden(
 633                 struct device_attribute **attrs,
 634                 struct device_attribute *attr)
 635 {
 636         int i;
 637
 638         if (!attrs)
 639                 return NULL;
 640         for (i = 0; attrs[i]; i++)
 641                 if (!strcmp(attrs[i]->attr.name, attr->attr.name))
 642                         return attrs[i];
 643         return NULL;
 644 }
 645
 646 static int attr_add(struct device *dev, struct device_attribute *attr)
 647 {
 648         struct device_attribute *base_attr;
 649
 650         /*
 651          * Spare the caller from having to copy things it's not interested in.
 652          */
 653         base_attr = attr_overridden(scsi_sysfs_sdev_attrs, attr);
 654         if (base_attr) {
 655                 /* extend permissions */
 656                 attr->attr.mode |= base_attr->attr.mode;
 657
 658                 /* override null show/store with default */
 659                 if (!attr->show)
 660                         attr->show = base_attr->show;
 661                 if (!attr->store)
 662                         attr->store = base_attr->store;
 663         }
 664
 665         return device_create_file(dev, attr);
 666 }
 667
 668 /**
 669  * scsi_sysfs_add_sdev - add scsi device to sysfs
 670  * @sdev:       scsi_device to add
 671  *
 672  * Return value:
 673  *      0 on Success / non-zero on Failure
 674  **/
 675 int scsi_sysfs_add_sdev(struct scsi_device *sdev)
 676 {
 677         int error, i;
 678
 679         if ((error = scsi_device_set_state(sdev, SDEV_RUNNING)) != 0)
 680                 return error;
 681
 682         error = device_add(&sdev->sdev_gendev);
 683         if (error) {
 684                 put_device(sdev->sdev_gendev.parent);
 685                 printk(KERN_INFO "error 1\n");
 686                 return error;
 687         }
 688         error = class_device_add(&sdev->sdev_classdev);
 689         if (error) {
 690                 printk(KERN_INFO "error 2\n");
 691                 goto clean_device;
 692         }
 693
 694         /* take a reference for the sdev_classdev; this is
 695          * released by the sdev_class .release */
 696         get_device(&sdev->sdev_gendev);
 697         if (sdev->host->hostt->sdev_attrs) {
 698                 for (i = 0; sdev->host->hostt->sdev_attrs[i]; i++) {
 699                         error = attr_add(&sdev->sdev_gendev,
 700                                         sdev->host->hostt->sdev_attrs[i]);
 701                         if (error) {
 702                                 __scsi_remove_device(sdev);
 703                                 goto out;
 704                         }
 705                 }
 706         }
 707
 708         for (i = 0; scsi_sysfs_sdev_attrs[i]; i++) {
 709                 if (!attr_overridden(sdev->host->hostt->sdev_attrs,
 710                                         scsi_sysfs_sdev_attrs[i])) {
 711                         struct device_attribute * attr =
 712                                 attr_changed_internally(sdev->host,
 713                                                         scsi_sysfs_sdev_attrs[i]);
 714                         error = device_create_file(&sdev->sdev_gendev, attr);
 715                         if (error) {
 716                                 __scsi_remove_device(sdev);
 717                                 goto out;
 718                         }
 719                 }
 720         }
 721
 722         transport_add_device(&sdev->sdev_gendev);
 723  out:
 724         return error;
 725
 726  clean_device:
 727         scsi_device_set_state(sdev, SDEV_CANCEL);
 728
 729         device_del(&sdev->sdev_gendev);
 730         transport_destroy_device(&sdev->sdev_gendev);
 731         put_device(&sdev->sdev_gendev);
 732
 733         return error;
 734 }
 735
 736 void __scsi_remove_device(struct scsi_device *sdev)
 737 {
 738         struct device *dev = &sdev->sdev_gendev;
 739
 740         if (scsi_device_set_state(sdev, SDEV_CANCEL) != 0)
 741                 return;
 742
 743         class_device_unregister(&sdev->sdev_classdev);
 744         transport_remove_device(dev);
 745         device_del(dev);
 746         scsi_device_set_state(sdev, SDEV_DEL);
 747         if (sdev->host->hostt->slave_destroy)
 748                 sdev->host->hostt->slave_destroy(sdev);
 749         transport_destroy_device(dev);
 750         put_device(dev);
 751 }
 752
 753 /**
 754  * scsi_remove_device - unregister a device from the scsi bus
 755  * @sdev:       scsi_device to unregister
 756  **/
 757 void scsi_remove_device(struct scsi_device *sdev)
 758 {
 759         struct Scsi_Host *shost = sdev->host;
 760
 761         mutex_lock(&shost->scan_mutex);
 762         __scsi_remove_device(sdev);
 763         mutex_unlock(&shost->scan_mutex);
 764 }
 765 EXPORT_SYMBOL(scsi_remove_device);
 766
 767 void __scsi_remove_target(struct scsi_target *starget)
 768 {
 769         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
 770         unsigned long flags;
 771         struct scsi_device *sdev;
 772
 773         spin_lock_irqsave(shost->host_lock, flags);
 774         starget->reap_ref++;
 775  restart:
 776         list_for_each_entry(sdev, &shost->__devices, siblings) {
 777                 if (sdev->channel != starget->channel ||
 778                     sdev->id != starget->id ||
 779                     sdev->sdev_state == SDEV_DEL)
 780                         continue;
 781                 spin_unlock_irqrestore(shost->host_lock, flags);
 782                 scsi_remove_device(sdev);
 783                 spin_lock_irqsave(shost->host_lock, flags);
 784                 goto restart;
 785         }
 786         spin_unlock_irqrestore(shost->host_lock, flags);
 787         scsi_target_reap(starget);
 788 }
 789
 790 static int __remove_child (struct device * dev, void * data)
 791 {
 792         if (scsi_is_target_device(dev))
 793                 __scsi_remove_target(to_scsi_target(dev));
 794         return 0;
 795 }
 796
 797 /**
 798  * scsi_remove_target - try to remove a target and all its devices
 799  * @dev: generic starget or parent of generic stargets to be removed
 800  *
 801  * Note: This is slightly racy.  It is possible that if the user
 802  * requests the addition of another device then the target won't be
 803  * removed.
 804  */
 805 void scsi_remove_target(struct device *dev)
 806 {
 807         struct device *rdev;
 808
 809         if (scsi_is_target_device(dev)) {
 810                 __scsi_remove_target(to_scsi_target(dev));
 811                 return;
 812         }
 813
 814         rdev = get_device(dev);
 815         device_for_each_child(dev, NULL, __remove_child);
 816         put_device(rdev);
 817 }
 818 EXPORT_SYMBOL(scsi_remove_target);
 819
 820 int scsi_register_driver(struct device_driver *drv)
 821 {
 822         drv->bus = &scsi_bus_type;
 823
 824         return driver_register(drv);
 825 }
 826 EXPORT_SYMBOL(scsi_register_driver);
 827
 828 int scsi_register_interface(struct class_interface *intf)
 829 {
 830         intf->class = &sdev_class;
 831
 832         return class_interface_register(intf);
 833 }
 834 EXPORT_SYMBOL(scsi_register_interface);
 835
 836
 837 static struct class_device_attribute *class_attr_overridden(
 838                 struct class_device_attribute **attrs,
 839                 struct class_device_attribute *attr)
 840 {
 841         int i;
 842
 843         if (!attrs)
 844                 return NULL;
 845         for (i = 0; attrs[i]; i++)
 846                 if (!strcmp(attrs[i]->attr.name, attr->attr.name))
 847                         return attrs[i];
 848         return NULL;
 849 }
 850
 851 static int class_attr_add(struct class_device *classdev,
 852                 struct class_device_attribute *attr)
 853 {
 854         struct class_device_attribute *base_attr;
 855
 856         /*
 857          * Spare the caller from having to copy things it's not interested in.
 858          */
 859         base_attr = class_attr_overridden(scsi_sysfs_shost_attrs, attr);
 860         if (base_attr) {
 861                 /* extend permissions */
 862                 attr->attr.mode |= base_attr->attr.mode;
 863
 864                 /* override null show/store with default */
 865                 if (!attr->show)
 866                         attr->show = base_attr->show;
 867                 if (!attr->store)
 868                         attr->store = base_attr->store;
 869         }
 870
 871         return class_device_create_file(classdev, attr);
 872 }
 873
 874 /**
 875  * scsi_sysfs_add_host - add scsi host to subsystem
 876  * @shost:     scsi host struct to add to subsystem
 877  * @dev:       parent struct device pointer
 878  **/
 879 int scsi_sysfs_add_host(struct Scsi_Host *shost)
 880 {
 881         int error, i;
 882
 883         if (shost->hostt->shost_attrs) {
 884                 for (i = 0; shost->hostt->shost_attrs[i]; i++) {
 885                         error = class_attr_add(&shost->shost_classdev,
 886                                         shost->hostt->shost_attrs[i]);
 887                         if (error)
 888                                 return error;
 889                 }
 890         }
 891
 892         for (i = 0; scsi_sysfs_shost_attrs[i]; i++) {
 893                 if (!class_attr_overridden(shost->hostt->shost_attrs,
 894                                         scsi_sysfs_shost_attrs[i])) {
 895                         error = class_device_create_file(&shost->shost_classdev,
 896                                         scsi_sysfs_shost_attrs[i]);
 897                         if (error)
 898                                 return error;
 899                 }
 900         }
 901
 902         transport_register_device(&shost->shost_gendev);
 903         return 0;
 904 }
 905
 906 void scsi_sysfs_device_initialize(struct scsi_device *sdev)
 907 {
 908         unsigned long flags;
 909         struct Scsi_Host *shost = sdev->host;
 910         struct scsi_target  *starget = sdev->sdev_target;
 911
 912         device_initialize(&sdev->sdev_gendev);
 913         sdev->sdev_gendev.bus = &scsi_bus_type;
 914         sdev->sdev_gendev.release = scsi_device_dev_release;
 915         sprintf(sdev->sdev_gendev.bus_id,"%d:%d:%d:%d",
 916                 sdev->host->host_no, sdev->channel, sdev->id,
 917                 sdev->lun);
 918
 919         class_device_initialize(&sdev->sdev_classdev);
 920         sdev->sdev_classdev.dev = &sdev->sdev_gendev;
 921         sdev->sdev_classdev.class = &sdev_class;
 922         snprintf(sdev->sdev_classdev.class_id, BUS_ID_SIZE,
 923                  "%d:%d:%d:%d", sdev->host->host_no,
 924                  sdev->channel, sdev->id, sdev->lun);
 925         sdev->scsi_level = SCSI_2;
 926         transport_setup_device(&sdev->sdev_gendev);
 927         spin_lock_irqsave(shost->host_lock, flags);
 928         list_add_tail(&sdev->same_target_siblings, &starget->devices);
 929         list_add_tail(&sdev->siblings, &shost->__devices);
 930         spin_unlock_irqrestore(shost->host_lock, flags);
 931 }
 932
 933 int scsi_is_sdev_device(const struct device *dev)
 934 {
 935         return dev->release == scsi_device_dev_release;
 936 }
 937 EXPORT_SYMBOL(scsi_is_sdev_device);
 938
 939 /* A blank transport template that is used in drivers that don't
 940  * yet implement Transport Attributes */
 941 struct scsi_transport_template blank_transport_template = { { { {NULL, }, }, }, };