block/genhd.c

   1 /*
   2  *  gendisk handling
   3  */
   4
   5 #include <linux/module.h>
   6 #include <linux/fs.h>
   7 #include <linux/genhd.h>
   8 #include <linux/kdev_t.h>
   9 #include <linux/kernel.h>
  10 #include <linux/blkdev.h>
  11 #include <linux/init.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/seq_file.h>
  14 #include <linux/slab.h>
  15 #include <linux/kmod.h>
  16 #include <linux/kobj_map.h>
  17 #include <linux/buffer_head.h>
  18 #include <linux/mutex.h>
  19
  20 #include "blk.h"
  21
  22 static DEFINE_MUTEX(block_class_lock);
  23 #ifndef CONFIG_SYSFS_DEPRECATED
  24 struct kobject *block_depr;
  25 #endif
  26
  27 static struct device_type disk_type;
  28
  29 /*
  30  * Can be deleted altogether. Later.
  31  *
  32  */
  33 static struct blk_major_name {
  34         struct blk_major_name *next;
  35         int major;
  36         char name[16];
  37 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
  38
  39 /* index in the above - for now: assume no multimajor ranges */
  40 static inline int major_to_index(int major)
  41 {
  42         return major % BLKDEV_MAJOR_HASH_SIZE;
  43 }
  44
  45 #ifdef CONFIG_PROC_FS
  46 void blkdev_show(struct seq_file *f, off_t offset)
  47 {
  48         struct blk_major_name *dp;
  49
  50         if (offset < BLKDEV_MAJOR_HASH_SIZE) {
  51                 mutex_lock(&block_class_lock);
  52                 for (dp = major_names[offset]; dp; dp = dp->next)
  53                         seq_printf(f, "%3d %s\n", dp->major, dp->name);
  54                 mutex_unlock(&block_class_lock);
  55         }
  56 }
  57 #endif /* CONFIG_PROC_FS */
  58
  59 int register_blkdev(unsigned int major, const char *name)
  60 {
  61         struct blk_major_name **n, *p;
  62         int index, ret = 0;
  63
  64         mutex_lock(&block_class_lock);
  65
  66         /* temporary */
  67         if (major == 0) {
  68                 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
  69                         if (major_names[index] == NULL)
  70                                 break;
  71                 }
  72
  73                 if (index == 0) {
  74                         printk("register_blkdev: failed to get major for %s\n",
  75                                name);
  76                         ret = -EBUSY;
  77                         goto out;
  78                 }
  79                 major = index;
  80                 ret = major;
  81         }
  82
  83         p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
  84         if (p == NULL) {
  85                 ret = -ENOMEM;
  86                 goto out;
  87         }
  88
  89         p->major = major;
  90         strlcpy(p->name, name, sizeof(p->name));
  91         p->next = NULL;
  92         index = major_to_index(major);
  93
  94         for (n = &major_names[index]; *n; n = &(*n)->next) {
  95                 if ((*n)->major == major)
  96                         break;
  97         }
  98         if (!*n)
  99                 *n = p;
 100         else
 101                 ret = -EBUSY;
 102
 103         if (ret < 0) {
 104                 printk("register_blkdev: cannot get major %d for %s\n",
 105                        major, name);
 106                 kfree(p);
 107         }
 108 out:
 109         mutex_unlock(&block_class_lock);
 110         return ret;
 111 }
 112
 113 EXPORT_SYMBOL(register_blkdev);
 114
 115 void unregister_blkdev(unsigned int major, const char *name)
 116 {
 117         struct blk_major_name **n;
 118         struct blk_major_name *p = NULL;
 119         int index = major_to_index(major);
 120
 121         mutex_lock(&block_class_lock);
 122         for (n = &major_names[index]; *n; n = &(*n)->next)
 123                 if ((*n)->major == major)
 124                         break;
 125         if (!*n || strcmp((*n)->name, name)) {
 126                 WARN_ON(1);
 127         } else {
 128                 p = *n;
 129                 *n = p->next;
 130         }
 131         mutex_unlock(&block_class_lock);
 132         kfree(p);
 133 }
 134
 135 EXPORT_SYMBOL(unregister_blkdev);
 136
 137 static struct kobj_map *bdev_map;
 138
 139 /*
 140  * Register device numbers dev..(dev+range-1)
 141  * range must be nonzero
 142  * The hash chain is sorted on range, so that subranges can override.
 143  */
 144 void blk_register_region(dev_t devt, unsigned long range, struct module *module,
 145                          struct kobject *(*probe)(dev_t, int *, void *),
 146                          int (*lock)(dev_t, void *), void *data)
 147 {
 148         kobj_map(bdev_map, devt, range, module, probe, lock, data);
 149 }
 150
 151 EXPORT_SYMBOL(blk_register_region);
 152
 153 void blk_unregister_region(dev_t devt, unsigned long range)
 154 {
 155         kobj_unmap(bdev_map, devt, range);
 156 }
 157
 158 EXPORT_SYMBOL(blk_unregister_region);
 159
 160 static struct kobject *exact_match(dev_t devt, int *part, void *data)
 161 {
 162         struct gendisk *p = data;
 163
 164         return &p->dev.kobj;
 165 }
 166
 167 static int exact_lock(dev_t devt, void *data)
 168 {
 169         struct gendisk *p = data;
 170
 171         if (!get_disk(p))
 172                 return -1;
 173         return 0;
 174 }
 175
 176 /**
 177  * add_disk - add partitioning information to kernel list
 178  * @disk: per-device partitioning information
 179  *
 180  * This function registers the partitioning information in @disk
 181  * with the kernel.
 182  */
 183 void add_disk(struct gendisk *disk)
 184 {
 185         struct backing_dev_info *bdi;
 186         int retval;
 187
 188         disk->flags |= GENHD_FL_UP;
 189         blk_register_region(MKDEV(disk->major, disk->first_minor),
 190                             disk->minors, NULL, exact_match, exact_lock, disk);
 191         register_disk(disk);
 192         blk_register_queue(disk);
 193
 194         bdi = &disk->queue->backing_dev_info;
 195         bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor));
 196         retval = sysfs_create_link(&disk->dev.kobj, &bdi->dev->kobj, "bdi");
 197         WARN_ON(retval);
 198 }
 199
 200 EXPORT_SYMBOL(add_disk);
 201 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 202
 203 void unlink_gendisk(struct gendisk *disk)
 204 {
 205         sysfs_remove_link(&disk->dev.kobj, "bdi");
 206         bdi_unregister(&disk->queue->backing_dev_info);
 207         blk_unregister_queue(disk);
 208         blk_unregister_region(MKDEV(disk->major, disk->first_minor),
 209                               disk->minors);
 210 }
 211
 212 /**
 213  * get_gendisk - get partitioning information for a given device
 214  * @dev: device to get partitioning information for
 215  *
 216  * This function gets the structure containing partitioning
 217  * information for the given device @dev.
 218  */
 219 struct gendisk *get_gendisk(dev_t devt, int *part)
 220 {
 221         struct kobject *kobj = kobj_lookup(bdev_map, devt, part);
 222         struct device *dev = kobj_to_dev(kobj);
 223
 224         return  kobj ? dev_to_disk(dev) : NULL;
 225 }
 226
 227 /*
 228  * print a partitions - intended for places where the root filesystem can't be
 229  * mounted and thus to give the victim some idea of what went wrong
 230  */
 231 static int printk_partition(struct device *dev, void *data)
 232 {
 233         struct gendisk *sgp;
 234         char buf[BDEVNAME_SIZE];
 235         int n;
 236
 237         if (dev->type != &disk_type)
 238                 goto exit;
 239
 240         sgp = dev_to_disk(dev);
 241         /*
 242          * Don't show empty devices or things that have been surpressed
 243          */
 244         if (get_capacity(sgp) == 0 ||
 245             (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 246                 goto exit;
 247
 248         /*
 249          * Note, unlike /proc/partitions, I am showing the numbers in
 250          * hex - the same format as the root= option takes.
 251          */
 252         printk("%02x%02x %10llu %s",
 253                 sgp->major, sgp->first_minor,
 254                 (unsigned long long)get_capacity(sgp) >> 1,
 255                 disk_name(sgp, 0, buf));
 256         if (sgp->driverfs_dev != NULL &&
 257             sgp->driverfs_dev->driver != NULL)
 258                 printk(" driver: %s\n",
 259                         sgp->driverfs_dev->driver->name);
 260         else
 261                 printk(" (driver?)\n");
 262
 263         /* now show the partitions */
 264         for (n = 0; n < sgp->minors - 1; ++n) {
 265                 if (sgp->part[n] == NULL)
 266                         goto exit;
 267                 if (sgp->part[n]->nr_sects == 0)
 268                         goto exit;
 269                 printk("  %02x%02x %10llu %s\n",
 270                         sgp->major, n + 1 + sgp->first_minor,
 271                         (unsigned long long)sgp->part[n]->nr_sects >> 1,
 272                         disk_name(sgp, n + 1, buf));
 273         }
 274 exit:
 275         return 0;
 276 }
 277
 278 /*
 279  * print a full list of all partitions - intended for places where the root
 280  * filesystem can't be mounted and thus to give the victim some idea of what
 281  * went wrong
 282  */
 283 void __init printk_all_partitions(void)
 284 {
 285         mutex_lock(&block_class_lock);
 286         class_for_each_device(&block_class, NULL, NULL, printk_partition);
 287         mutex_unlock(&block_class_lock);
 288 }
 289
 290 #ifdef CONFIG_PROC_FS
 291 /* iterator */
 292 static int find_start(struct device *dev, void *data)
 293 {
 294         loff_t *k = data;
 295
 296         if (dev->type != &disk_type)
 297                 return 0;
 298         if (!*k)
 299                 return 1;
 300         (*k)--;
 301         return 0;
 302 }
 303
 304 static void *part_start(struct seq_file *part, loff_t *pos)
 305 {
 306         struct device *dev;
 307         loff_t k = *pos;
 308
 309         if (!k)
 310                 part->private = (void *)1LU;    /* tell show to print header */
 311
 312         mutex_lock(&block_class_lock);
 313         dev = class_find_device(&block_class, NULL, &k, find_start);
 314         if (dev) {
 315                 put_device(dev);
 316                 return dev_to_disk(dev);
 317         }
 318         return NULL;
 319 }
 320
 321 static int find_next(struct device *dev, void *data)
 322 {
 323         if (dev->type == &disk_type)
 324                 return 1;
 325         return 0;
 326 }
 327
 328 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 329 {
 330         struct gendisk *gp = v;
 331         struct device *dev;
 332         ++*pos;
 333         dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
 334         if (dev) {
 335                 put_device(dev);
 336                 return dev_to_disk(dev);
 337         }
 338         return NULL;
 339 }
 340
 341 static void part_stop(struct seq_file *part, void *v)
 342 {
 343         mutex_unlock(&block_class_lock);
 344 }
 345
 346 static int show_partition(struct seq_file *part, void *v)
 347 {
 348         struct gendisk *sgp = v;
 349         int n;
 350         char buf[BDEVNAME_SIZE];
 351
 352         /*
 353          * Print header if start told us to do.  This is to preserve
 354          * the original behavior of not printing header if no
 355          * partition exists.  This hackery will be removed later with
 356          * class iteration clean up.
 357          */
 358         if (part->private) {
 359                 seq_puts(part, "major minor  #blocks  name\n\n");
 360                 part->private = NULL;
 361         }
 362
 363         /* Don't show non-partitionable removeable devices or empty devices */
 364         if (!get_capacity(sgp) ||
 365                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 366                 return 0;
 367         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 368                 return 0;
 369
 370         /* show the full disk and all non-0 size partitions of it */
 371         seq_printf(part, "%4d  %4d %10llu %s\n",
 372                 sgp->major, sgp->first_minor,
 373                 (unsigned long long)get_capacity(sgp) >> 1,
 374                 disk_name(sgp, 0, buf));
 375         for (n = 0; n < sgp->minors - 1; n++) {
 376                 if (!sgp->part[n])
 377                         continue;
 378                 if (sgp->part[n]->nr_sects == 0)
 379                         continue;
 380                 seq_printf(part, "%4d  %4d %10llu %s\n",
 381                         sgp->major, n + 1 + sgp->first_minor,
 382                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 383                         disk_name(sgp, n + 1, buf));
 384         }
 385
 386         return 0;
 387 }
 388
 389 const struct seq_operations partitions_op = {
 390         .start  = part_start,
 391         .next   = part_next,
 392         .stop   = part_stop,
 393         .show   = show_partition
 394 };
 395 #endif
 396
 397
 398 static struct kobject *base_probe(dev_t devt, int *part, void *data)
 399 {
 400         if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
 401                 /* Make old-style 2.4 aliases work */
 402                 request_module("block-major-%d", MAJOR(devt));
 403         return NULL;
 404 }
 405
 406 static int __init genhd_device_init(void)
 407 {
 408         int error;
 409
 410         block_class.dev_kobj = sysfs_dev_block_kobj;
 411         error = class_register(&block_class);
 412         if (unlikely(error))
 413                 return error;
 414         bdev_map = kobj_map_init(base_probe, &block_class_lock);
 415         blk_dev_init();
 416
 417 #ifndef CONFIG_SYSFS_DEPRECATED
 418         /* create top-level block dir */
 419         block_depr = kobject_create_and_add("block", NULL);
 420 #endif
 421         return 0;
 422 }
 423
 424 subsys_initcall(genhd_device_init);
 425
 426 static ssize_t disk_range_show(struct device *dev,
 427                                struct device_attribute *attr, char *buf)
 428 {
 429         struct gendisk *disk = dev_to_disk(dev);
 430
 431         return sprintf(buf, "%d\n", disk->minors);
 432 }
 433
 434 static ssize_t disk_removable_show(struct device *dev,
 435                                    struct device_attribute *attr, char *buf)
 436 {
 437         struct gendisk *disk = dev_to_disk(dev);
 438
 439         return sprintf(buf, "%d\n",
 440                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 441 }
 442
 443 static ssize_t disk_ro_show(struct device *dev,
 444                                    struct device_attribute *attr, char *buf)
 445 {
 446         struct gendisk *disk = dev_to_disk(dev);
 447
 448         return sprintf(buf, "%d\n", disk->policy ? 1 : 0);
 449 }
 450
 451 static ssize_t disk_size_show(struct device *dev,
 452                               struct device_attribute *attr, char *buf)
 453 {
 454         struct gendisk *disk = dev_to_disk(dev);
 455
 456         return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
 457 }
 458
 459 static ssize_t disk_capability_show(struct device *dev,
 460                                     struct device_attribute *attr, char *buf)
 461 {
 462         struct gendisk *disk = dev_to_disk(dev);
 463
 464         return sprintf(buf, "%x\n", disk->flags);
 465 }
 466
 467 static ssize_t disk_stat_show(struct device *dev,
 468                               struct device_attribute *attr, char *buf)
 469 {
 470         struct gendisk *disk = dev_to_disk(dev);
 471
 472         preempt_disable();
 473         disk_round_stats(disk);
 474         preempt_enable();
 475         return sprintf(buf,
 476                 "%8lu %8lu %8llu %8u "
 477                 "%8lu %8lu %8llu %8u "
 478                 "%8u %8u %8u"
 479                 "\n",
 480                 disk_stat_read(disk, ios[READ]),
 481                 disk_stat_read(disk, merges[READ]),
 482                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 483                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 484                 disk_stat_read(disk, ios[WRITE]),
 485                 disk_stat_read(disk, merges[WRITE]),
 486                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 487                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 488                 disk->in_flight,
 489                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 490                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 491 }
 492
 493 #ifdef CONFIG_FAIL_MAKE_REQUEST
 494 static ssize_t disk_fail_show(struct device *dev,
 495                               struct device_attribute *attr, char *buf)
 496 {
 497         struct gendisk *disk = dev_to_disk(dev);
 498
 499         return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 500 }
 501
 502 static ssize_t disk_fail_store(struct device *dev,
 503                                struct device_attribute *attr,
 504                                const char *buf, size_t count)
 505 {
 506         struct gendisk *disk = dev_to_disk(dev);
 507         int i;
 508
 509         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 510                 if (i == 0)
 511                         disk->flags &= ~GENHD_FL_FAIL;
 512                 else
 513                         disk->flags |= GENHD_FL_FAIL;
 514         }
 515
 516         return count;
 517 }
 518
 519 #endif
 520
 521 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 522 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
 523 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
 524 static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
 525 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
 526 static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
 527 #ifdef CONFIG_FAIL_MAKE_REQUEST
 528 static struct device_attribute dev_attr_fail =
 529         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
 530 #endif
 531
 532 static struct attribute *disk_attrs[] = {
 533         &dev_attr_range.attr,
 534         &dev_attr_removable.attr,
 535         &dev_attr_ro.attr,
 536         &dev_attr_size.attr,
 537         &dev_attr_capability.attr,
 538         &dev_attr_stat.attr,
 539 #ifdef CONFIG_FAIL_MAKE_REQUEST
 540         &dev_attr_fail.attr,
 541 #endif
 542         NULL
 543 };
 544
 545 static struct attribute_group disk_attr_group = {
 546         .attrs = disk_attrs,
 547 };
 548
 549 static struct attribute_group *disk_attr_groups[] = {
 550         &disk_attr_group,
 551         NULL
 552 };
 553
 554 static void disk_release(struct device *dev)
 555 {
 556         struct gendisk *disk = dev_to_disk(dev);
 557
 558         kfree(disk->random);
 559         kfree(disk->part);
 560         free_disk_stats(disk);
 561         kfree(disk);
 562 }
 563 struct class block_class = {
 564         .name           = "block",
 565 };
 566
 567 static struct device_type disk_type = {
 568         .name           = "disk",
 569         .groups         = disk_attr_groups,
 570         .release        = disk_release,
 571 };
 572
 573 #ifdef CONFIG_PROC_FS
 574 /*
 575  * aggregate disk stat collector.  Uses the same stats that the sysfs
 576  * entries do, above, but makes them available through one seq_file.
 577  *
 578  * The output looks suspiciously like /proc/partitions with a bunch of
 579  * extra fields.
 580  */
 581
 582 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 583 {
 584         struct device *dev;
 585         loff_t k = *pos;
 586
 587         mutex_lock(&block_class_lock);
 588         dev = class_find_device(&block_class, NULL, &k, find_start);
 589         if (dev) {
 590                 put_device(dev);
 591                 return dev_to_disk(dev);
 592         }
 593         return NULL;
 594 }
 595
 596 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 597 {
 598         struct gendisk *gp = v;
 599         struct device *dev;
 600
 601         ++*pos;
 602         dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
 603         if (dev) {
 604                 put_device(dev);
 605                 return dev_to_disk(dev);
 606         }
 607         return NULL;
 608 }
 609
 610 static void diskstats_stop(struct seq_file *part, void *v)
 611 {
 612         mutex_unlock(&block_class_lock);
 613 }
 614
 615 static int diskstats_show(struct seq_file *s, void *v)
 616 {
 617         struct gendisk *gp = v;
 618         char buf[BDEVNAME_SIZE];
 619         int n = 0;
 620
 621         /*
 622         if (&gp->dev.kobj.entry == block_class.devices.next)
 623                 seq_puts(s,     "major minor name"
 624                                 "     rio rmerge rsect ruse wio wmerge "
 625                                 "wsect wuse running use aveq"
 626                                 "\n\n");
 627         */
 628
 629         preempt_disable();
 630         disk_round_stats(gp);
 631         preempt_enable();
 632         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 633                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 634                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 635                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 636                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 637                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 638                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 639                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 640                 gp->in_flight,
 641                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 642                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 643
 644         /* now show all non-0 size partitions of it */
 645         for (n = 0; n < gp->minors - 1; n++) {
 646                 struct hd_struct *hd = gp->part[n];
 647
 648                 if (!hd || !hd->nr_sects)
 649                         continue;
 650
 651                 preempt_disable();
 652                 part_round_stats(hd);
 653                 preempt_enable();
 654                 seq_printf(s, "%4d %4d %s %lu %lu %llu "
 655                            "%u %lu %lu %llu %u %u %u %u\n",
 656                            gp->major, n + gp->first_minor + 1,
 657                            disk_name(gp, n + 1, buf),
 658                            part_stat_read(hd, ios[0]),
 659                            part_stat_read(hd, merges[0]),
 660                            (unsigned long long)part_stat_read(hd, sectors[0]),
 661                            jiffies_to_msecs(part_stat_read(hd, ticks[0])),
 662                            part_stat_read(hd, ios[1]),
 663                            part_stat_read(hd, merges[1]),
 664                            (unsigned long long)part_stat_read(hd, sectors[1]),
 665                            jiffies_to_msecs(part_stat_read(hd, ticks[1])),
 666                            hd->in_flight,
 667                            jiffies_to_msecs(part_stat_read(hd, io_ticks)),
 668                            jiffies_to_msecs(part_stat_read(hd, time_in_queue))
 669                         );
 670         }
 671
 672         return 0;
 673 }
 674
 675 const struct seq_operations diskstats_op = {
 676         .start  = diskstats_start,
 677         .next   = diskstats_next,
 678         .stop   = diskstats_stop,
 679         .show   = diskstats_show
 680 };
 681 #endif /* CONFIG_PROC_FS */
 682
 683 static void media_change_notify_thread(struct work_struct *work)
 684 {
 685         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 686         char event[] = "MEDIA_CHANGE=1";
 687         char *envp[] = { event, NULL };
 688
 689         /*
 690          * set enviroment vars to indicate which event this is for
 691          * so that user space will know to go check the media status.
 692          */
 693         kobject_uevent_env(&gd->dev.kobj, KOBJ_CHANGE, envp);
 694         put_device(gd->driverfs_dev);
 695 }
 696
 697 #if 0
 698 void genhd_media_change_notify(struct gendisk *disk)
 699 {
 700         get_device(disk->driverfs_dev);
 701         schedule_work(&disk->async_notify);
 702 }
 703 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 704 #endif  /*  0  */
 705
 706 struct find_block {
 707         const char *name;
 708         int part;
 709 };
 710
 711 static int match_id(struct device *dev, void *data)
 712 {
 713         struct find_block *find = data;
 714
 715         if (dev->type != &disk_type)
 716                 return 0;
 717         if (strcmp(dev->bus_id, find->name) == 0) {
 718                 struct gendisk *disk = dev_to_disk(dev);
 719                 if (find->part < disk->minors)
 720                         return 1;
 721         }
 722         return 0;
 723 }
 724
 725 dev_t blk_lookup_devt(const char *name, int part)
 726 {
 727         struct device *dev;
 728         dev_t devt = MKDEV(0, 0);
 729         struct find_block find;
 730
 731         mutex_lock(&block_class_lock);
 732         find.name = name;
 733         find.part = part;
 734         dev = class_find_device(&block_class, NULL, &find, match_id);
 735         if (dev) {
 736                 put_device(dev);
 737                 devt = MKDEV(MAJOR(dev->devt),
 738                              MINOR(dev->devt) + part);
 739         }
 740         mutex_unlock(&block_class_lock);
 741
 742         return devt;
 743 }
 744 EXPORT_SYMBOL(blk_lookup_devt);
 745
 746 struct gendisk *alloc_disk(int minors)
 747 {
 748         return alloc_disk_node(minors, -1);
 749 }
 750
 751 struct gendisk *alloc_disk_node(int minors, int node_id)
 752 {
 753         struct gendisk *disk;
 754
 755         disk = kmalloc_node(sizeof(struct gendisk),
 756                                 GFP_KERNEL | __GFP_ZERO, node_id);
 757         if (disk) {
 758                 if (!init_disk_stats(disk)) {
 759                         kfree(disk);
 760                         return NULL;
 761                 }
 762                 if (minors > 1) {
 763                         int size = (minors - 1) * sizeof(struct hd_struct *);
 764                         disk->part = kmalloc_node(size,
 765                                 GFP_KERNEL | __GFP_ZERO, node_id);
 766                         if (!disk->part) {
 767                                 free_disk_stats(disk);
 768                                 kfree(disk);
 769                                 return NULL;
 770                         }
 771                 }
 772                 disk->minors = minors;
 773                 rand_initialize_disk(disk);
 774                 disk->dev.class = &block_class;
 775                 disk->dev.type = &disk_type;
 776                 device_initialize(&disk->dev);
 777                 INIT_WORK(&disk->async_notify,
 778                         media_change_notify_thread);
 779         }
 780         return disk;
 781 }
 782
 783 EXPORT_SYMBOL(alloc_disk);
 784 EXPORT_SYMBOL(alloc_disk_node);
 785
 786 struct kobject *get_disk(struct gendisk *disk)
 787 {
 788         struct module *owner;
 789         struct kobject *kobj;
 790
 791         if (!disk->fops)
 792                 return NULL;
 793         owner = disk->fops->owner;
 794         if (owner && !try_module_get(owner))
 795                 return NULL;
 796         kobj = kobject_get(&disk->dev.kobj);
 797         if (kobj == NULL) {
 798                 module_put(owner);
 799                 return NULL;
 800         }
 801         return kobj;
 802
 803 }
 804
 805 EXPORT_SYMBOL(get_disk);
 806
 807 void put_disk(struct gendisk *disk)
 808 {
 809         if (disk)
 810                 kobject_put(&disk->dev.kobj);
 811 }
 812
 813 EXPORT_SYMBOL(put_disk);
 814
 815 void set_device_ro(struct block_device *bdev, int flag)
 816 {
 817         if (bdev->bd_contains != bdev)
 818                 bdev->bd_part->policy = flag;
 819         else
 820                 bdev->bd_disk->policy = flag;
 821 }
 822
 823 EXPORT_SYMBOL(set_device_ro);
 824
 825 void set_disk_ro(struct gendisk *disk, int flag)
 826 {
 827         int i;
 828         disk->policy = flag;
 829         for (i = 0; i < disk->minors - 1; i++)
 830                 if (disk->part[i]) disk->part[i]->policy = flag;
 831 }
 832
 833 EXPORT_SYMBOL(set_disk_ro);
 834
 835 int bdev_read_only(struct block_device *bdev)
 836 {
 837         if (!bdev)
 838                 return 0;
 839         else if (bdev->bd_contains != bdev)
 840                 return bdev->bd_part->policy;
 841         else
 842                 return bdev->bd_disk->policy;
 843 }
 844
 845 EXPORT_SYMBOL(bdev_read_only);
 846
 847 int invalidate_partition(struct gendisk *disk, int index)
 848 {
 849         int res = 0;
 850         struct block_device *bdev = bdget_disk(disk, index);
 851         if (bdev) {
 852                 fsync_bdev(bdev);
 853                 res = __invalidate_device(bdev);
 854                 bdput(bdev);
 855         }
 856         return res;
 857 }
 858
 859 EXPORT_SYMBOL(invalidate_partition);