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         disk->flags |= GENHD_FL_UP;
 186         blk_register_region(MKDEV(disk->major, disk->first_minor),
 187                             disk->minors, NULL, exact_match, exact_lock, disk);
 188         register_disk(disk);
 189         blk_register_queue(disk);
 190 }
 191
 192 EXPORT_SYMBOL(add_disk);
 193 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 194
 195 void unlink_gendisk(struct gendisk *disk)
 196 {
 197         blk_unregister_queue(disk);
 198         blk_unregister_region(MKDEV(disk->major, disk->first_minor),
 199                               disk->minors);
 200 }
 201
 202 /**
 203  * get_gendisk - get partitioning information for a given device
 204  * @dev: device to get partitioning information for
 205  *
 206  * This function gets the structure containing partitioning
 207  * information for the given device @dev.
 208  */
 209 struct gendisk *get_gendisk(dev_t devt, int *part)
 210 {
 211         struct kobject *kobj = kobj_lookup(bdev_map, devt, part);
 212         struct device *dev = kobj_to_dev(kobj);
 213
 214         return  kobj ? dev_to_disk(dev) : NULL;
 215 }
 216
 217 /*
 218  * print a full list of all partitions - intended for places where the root
 219  * filesystem can't be mounted and thus to give the victim some idea of what
 220  * went wrong
 221  */
 222 void __init printk_all_partitions(void)
 223 {
 224         struct device *dev;
 225         struct gendisk *sgp;
 226         char buf[BDEVNAME_SIZE];
 227         int n;
 228
 229         mutex_lock(&block_class_lock);
 230         /* For each block device... */
 231         list_for_each_entry(dev, &block_class.devices, node) {
 232                 if (dev->type != &disk_type)
 233                         continue;
 234                 sgp = dev_to_disk(dev);
 235                 /*
 236                  * Don't show empty devices or things that have been surpressed
 237                  */
 238                 if (get_capacity(sgp) == 0 ||
 239                     (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 240                         continue;
 241
 242                 /*
 243                  * Note, unlike /proc/partitions, I am showing the numbers in
 244                  * hex - the same format as the root= option takes.
 245                  */
 246                 printk("%02x%02x %10llu %s",
 247                         sgp->major, sgp->first_minor,
 248                         (unsigned long long)get_capacity(sgp) >> 1,
 249                         disk_name(sgp, 0, buf));
 250                 if (sgp->driverfs_dev != NULL &&
 251                     sgp->driverfs_dev->driver != NULL)
 252                         printk(" driver: %s\n",
 253                                 sgp->driverfs_dev->driver->name);
 254                 else
 255                         printk(" (driver?)\n");
 256
 257                 /* now show the partitions */
 258                 for (n = 0; n < sgp->minors - 1; ++n) {
 259                         if (sgp->part[n] == NULL)
 260                                 continue;
 261                         if (sgp->part[n]->nr_sects == 0)
 262                                 continue;
 263                         printk("  %02x%02x %10llu %s\n",
 264                                 sgp->major, n + 1 + sgp->first_minor,
 265                                 (unsigned long long)sgp->part[n]->nr_sects >> 1,
 266                                 disk_name(sgp, n + 1, buf));
 267                 }
 268         }
 269
 270         mutex_unlock(&block_class_lock);
 271 }
 272
 273 #ifdef CONFIG_PROC_FS
 274 /* iterator */
 275 static void *part_start(struct seq_file *part, loff_t *pos)
 276 {
 277         loff_t k = *pos;
 278         struct device *dev;
 279
 280         mutex_lock(&block_class_lock);
 281         list_for_each_entry(dev, &block_class.devices, node) {
 282                 if (dev->type != &disk_type)
 283                         continue;
 284                 if (!k--)
 285                         return dev_to_disk(dev);
 286         }
 287         return NULL;
 288 }
 289
 290 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 291 {
 292         struct gendisk *gp = v;
 293         struct device *dev;
 294         ++*pos;
 295         list_for_each_entry(dev, &gp->dev.node, node) {
 296                 if (&dev->node == &block_class.devices)
 297                         return NULL;
 298                 if (dev->type == &disk_type)
 299                         return dev_to_disk(dev);
 300         }
 301         return NULL;
 302 }
 303
 304 static void part_stop(struct seq_file *part, void *v)
 305 {
 306         mutex_unlock(&block_class_lock);
 307 }
 308
 309 static int show_partition(struct seq_file *part, void *v)
 310 {
 311         struct gendisk *sgp = v;
 312         int n;
 313         char buf[BDEVNAME_SIZE];
 314
 315         if (&sgp->dev.node == block_class.devices.next)
 316                 seq_puts(part, "major minor  #blocks  name\n\n");
 317
 318         /* Don't show non-partitionable removeable devices or empty devices */
 319         if (!get_capacity(sgp) ||
 320                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 321                 return 0;
 322         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 323                 return 0;
 324
 325         /* show the full disk and all non-0 size partitions of it */
 326         seq_printf(part, "%4d  %4d %10llu %s\n",
 327                 sgp->major, sgp->first_minor,
 328                 (unsigned long long)get_capacity(sgp) >> 1,
 329                 disk_name(sgp, 0, buf));
 330         for (n = 0; n < sgp->minors - 1; n++) {
 331                 if (!sgp->part[n])
 332                         continue;
 333                 if (sgp->part[n]->nr_sects == 0)
 334                         continue;
 335                 seq_printf(part, "%4d  %4d %10llu %s\n",
 336                         sgp->major, n + 1 + sgp->first_minor,
 337                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 338                         disk_name(sgp, n + 1, buf));
 339         }
 340
 341         return 0;
 342 }
 343
 344 const struct seq_operations partitions_op = {
 345         .start  = part_start,
 346         .next   = part_next,
 347         .stop   = part_stop,
 348         .show   = show_partition
 349 };
 350 #endif
 351
 352
 353 static struct kobject *base_probe(dev_t devt, int *part, void *data)
 354 {
 355         if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
 356                 /* Make old-style 2.4 aliases work */
 357                 request_module("block-major-%d", MAJOR(devt));
 358         return NULL;
 359 }
 360
 361 static int __init genhd_device_init(void)
 362 {
 363         int error = class_register(&block_class);
 364         if (unlikely(error))
 365                 return error;
 366         bdev_map = kobj_map_init(base_probe, &block_class_lock);
 367         blk_dev_init();
 368
 369 #ifndef CONFIG_SYSFS_DEPRECATED
 370         /* create top-level block dir */
 371         block_depr = kobject_create_and_add("block", NULL);
 372 #endif
 373         return 0;
 374 }
 375
 376 subsys_initcall(genhd_device_init);
 377
 378 static ssize_t disk_range_show(struct device *dev,
 379                                struct device_attribute *attr, char *buf)
 380 {
 381         struct gendisk *disk = dev_to_disk(dev);
 382
 383         return sprintf(buf, "%d\n", disk->minors);
 384 }
 385
 386 static ssize_t disk_removable_show(struct device *dev,
 387                                    struct device_attribute *attr, char *buf)
 388 {
 389         struct gendisk *disk = dev_to_disk(dev);
 390
 391         return sprintf(buf, "%d\n",
 392                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 393 }
 394
 395 static ssize_t disk_size_show(struct device *dev,
 396                               struct device_attribute *attr, char *buf)
 397 {
 398         struct gendisk *disk = dev_to_disk(dev);
 399
 400         return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
 401 }
 402
 403 static ssize_t disk_capability_show(struct device *dev,
 404                                     struct device_attribute *attr, char *buf)
 405 {
 406         struct gendisk *disk = dev_to_disk(dev);
 407
 408         return sprintf(buf, "%x\n", disk->flags);
 409 }
 410
 411 static ssize_t disk_stat_show(struct device *dev,
 412                               struct device_attribute *attr, char *buf)
 413 {
 414         struct gendisk *disk = dev_to_disk(dev);
 415
 416         preempt_disable();
 417         disk_round_stats(disk);
 418         preempt_enable();
 419         return sprintf(buf,
 420                 "%8lu %8lu %8llu %8u "
 421                 "%8lu %8lu %8llu %8u "
 422                 "%8u %8u %8u"
 423                 "\n",
 424                 disk_stat_read(disk, ios[READ]),
 425                 disk_stat_read(disk, merges[READ]),
 426                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 427                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 428                 disk_stat_read(disk, ios[WRITE]),
 429                 disk_stat_read(disk, merges[WRITE]),
 430                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 431                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 432                 disk->in_flight,
 433                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 434                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 435 }
 436
 437 #ifdef CONFIG_FAIL_MAKE_REQUEST
 438 static ssize_t disk_fail_show(struct device *dev,
 439                               struct device_attribute *attr, char *buf)
 440 {
 441         struct gendisk *disk = dev_to_disk(dev);
 442
 443         return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 444 }
 445
 446 static ssize_t disk_fail_store(struct device *dev,
 447                                struct device_attribute *attr,
 448                                const char *buf, size_t count)
 449 {
 450         struct gendisk *disk = dev_to_disk(dev);
 451         int i;
 452
 453         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 454                 if (i == 0)
 455                         disk->flags &= ~GENHD_FL_FAIL;
 456                 else
 457                         disk->flags |= GENHD_FL_FAIL;
 458         }
 459
 460         return count;
 461 }
 462
 463 #endif
 464
 465 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 466 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
 467 static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
 468 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
 469 static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
 470 #ifdef CONFIG_FAIL_MAKE_REQUEST
 471 static struct device_attribute dev_attr_fail =
 472         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
 473 #endif
 474
 475 static struct attribute *disk_attrs[] = {
 476         &dev_attr_range.attr,
 477         &dev_attr_removable.attr,
 478         &dev_attr_size.attr,
 479         &dev_attr_capability.attr,
 480         &dev_attr_stat.attr,
 481 #ifdef CONFIG_FAIL_MAKE_REQUEST
 482         &dev_attr_fail.attr,
 483 #endif
 484         NULL
 485 };
 486
 487 static struct attribute_group disk_attr_group = {
 488         .attrs = disk_attrs,
 489 };
 490
 491 static struct attribute_group *disk_attr_groups[] = {
 492         &disk_attr_group,
 493         NULL
 494 };
 495
 496 static void disk_release(struct device *dev)
 497 {
 498         struct gendisk *disk = dev_to_disk(dev);
 499
 500         kfree(disk->random);
 501         kfree(disk->part);
 502         free_disk_stats(disk);
 503         kfree(disk);
 504 }
 505 struct class block_class = {
 506         .name           = "block",
 507 };
 508
 509 static struct device_type disk_type = {
 510         .name           = "disk",
 511         .groups         = disk_attr_groups,
 512         .release        = disk_release,
 513 };
 514
 515 /*
 516  * aggregate disk stat collector.  Uses the same stats that the sysfs
 517  * entries do, above, but makes them available through one seq_file.
 518  *
 519  * The output looks suspiciously like /proc/partitions with a bunch of
 520  * extra fields.
 521  */
 522
 523 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 524 {
 525         loff_t k = *pos;
 526         struct device *dev;
 527
 528         mutex_lock(&block_class_lock);
 529         list_for_each_entry(dev, &block_class.devices, node) {
 530                 if (dev->type != &disk_type)
 531                         continue;
 532                 if (!k--)
 533                         return dev_to_disk(dev);
 534         }
 535         return NULL;
 536 }
 537
 538 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 539 {
 540         struct gendisk *gp = v;
 541         struct device *dev;
 542
 543         ++*pos;
 544         list_for_each_entry(dev, &gp->dev.node, node) {
 545                 if (&dev->node == &block_class.devices)
 546                         return NULL;
 547                 if (dev->type == &disk_type)
 548                         return dev_to_disk(dev);
 549         }
 550         return NULL;
 551 }
 552
 553 static void diskstats_stop(struct seq_file *part, void *v)
 554 {
 555         mutex_unlock(&block_class_lock);
 556 }
 557
 558 static int diskstats_show(struct seq_file *s, void *v)
 559 {
 560         struct gendisk *gp = v;
 561         char buf[BDEVNAME_SIZE];
 562         int n = 0;
 563
 564         /*
 565         if (&gp->dev.kobj.entry == block_class.devices.next)
 566                 seq_puts(s,     "major minor name"
 567                                 "     rio rmerge rsect ruse wio wmerge "
 568                                 "wsect wuse running use aveq"
 569                                 "\n\n");
 570         */
 571
 572         preempt_disable();
 573         disk_round_stats(gp);
 574         preempt_enable();
 575         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 576                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 577                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 578                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 579                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 580                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 581                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 582                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 583                 gp->in_flight,
 584                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 585                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 586
 587         /* now show all non-0 size partitions of it */
 588         for (n = 0; n < gp->minors - 1; n++) {
 589                 struct hd_struct *hd = gp->part[n];
 590
 591                 if (!hd || !hd->nr_sects)
 592                         continue;
 593
 594                 preempt_disable();
 595                 part_round_stats(hd);
 596                 preempt_enable();
 597                 seq_printf(s, "%4d %4d %s %lu %lu %llu "
 598                            "%u %lu %lu %llu %u %u %u %u\n",
 599                            gp->major, n + gp->first_minor + 1,
 600                            disk_name(gp, n + 1, buf),
 601                            part_stat_read(hd, ios[0]),
 602                            part_stat_read(hd, merges[0]),
 603                            (unsigned long long)part_stat_read(hd, sectors[0]),
 604                            jiffies_to_msecs(part_stat_read(hd, ticks[0])),
 605                            part_stat_read(hd, ios[1]),
 606                            part_stat_read(hd, merges[1]),
 607                            (unsigned long long)part_stat_read(hd, sectors[1]),
 608                            jiffies_to_msecs(part_stat_read(hd, ticks[1])),
 609                            hd->in_flight,
 610                            jiffies_to_msecs(part_stat_read(hd, io_ticks)),
 611                            jiffies_to_msecs(part_stat_read(hd, time_in_queue))
 612                         );
 613         }
 614
 615         return 0;
 616 }
 617
 618 const struct seq_operations diskstats_op = {
 619         .start  = diskstats_start,
 620         .next   = diskstats_next,
 621         .stop   = diskstats_stop,
 622         .show   = diskstats_show
 623 };
 624
 625 static void media_change_notify_thread(struct work_struct *work)
 626 {
 627         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 628         char event[] = "MEDIA_CHANGE=1";
 629         char *envp[] = { event, NULL };
 630
 631         /*
 632          * set enviroment vars to indicate which event this is for
 633          * so that user space will know to go check the media status.
 634          */
 635         kobject_uevent_env(&gd->dev.kobj, KOBJ_CHANGE, envp);
 636         put_device(gd->driverfs_dev);
 637 }
 638
 639 #if 0
 640 void genhd_media_change_notify(struct gendisk *disk)
 641 {
 642         get_device(disk->driverfs_dev);
 643         schedule_work(&disk->async_notify);
 644 }
 645 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 646 #endif  /*  0  */
 647
 648 dev_t blk_lookup_devt(const char *name)
 649 {
 650         struct device *dev;
 651         dev_t devt = MKDEV(0, 0);
 652
 653         mutex_lock(&block_class_lock);
 654         list_for_each_entry(dev, &block_class.devices, node) {
 655                 if (strcmp(dev->bus_id, name) == 0) {
 656                         devt = dev->devt;
 657                         break;
 658                 }
 659         }
 660         mutex_unlock(&block_class_lock);
 661
 662         return devt;
 663 }
 664
 665 EXPORT_SYMBOL(blk_lookup_devt);
 666
 667 struct gendisk *alloc_disk(int minors)
 668 {
 669         return alloc_disk_node(minors, -1);
 670 }
 671
 672 struct gendisk *alloc_disk_node(int minors, int node_id)
 673 {
 674         struct gendisk *disk;
 675
 676         disk = kmalloc_node(sizeof(struct gendisk),
 677                                 GFP_KERNEL | __GFP_ZERO, node_id);
 678         if (disk) {
 679                 if (!init_disk_stats(disk)) {
 680                         kfree(disk);
 681                         return NULL;
 682                 }
 683                 if (minors > 1) {
 684                         int size = (minors - 1) * sizeof(struct hd_struct *);
 685                         disk->part = kmalloc_node(size,
 686                                 GFP_KERNEL | __GFP_ZERO, node_id);
 687                         if (!disk->part) {
 688                                 free_disk_stats(disk);
 689                                 kfree(disk);
 690                                 return NULL;
 691                         }
 692                 }
 693                 disk->minors = minors;
 694                 rand_initialize_disk(disk);
 695                 disk->dev.class = &block_class;
 696                 disk->dev.type = &disk_type;
 697                 device_initialize(&disk->dev);
 698                 INIT_WORK(&disk->async_notify,
 699                         media_change_notify_thread);
 700         }
 701         return disk;
 702 }
 703
 704 EXPORT_SYMBOL(alloc_disk);
 705 EXPORT_SYMBOL(alloc_disk_node);
 706
 707 struct kobject *get_disk(struct gendisk *disk)
 708 {
 709         struct module *owner;
 710         struct kobject *kobj;
 711
 712         if (!disk->fops)
 713                 return NULL;
 714         owner = disk->fops->owner;
 715         if (owner && !try_module_get(owner))
 716                 return NULL;
 717         kobj = kobject_get(&disk->dev.kobj);
 718         if (kobj == NULL) {
 719                 module_put(owner);
 720                 return NULL;
 721         }
 722         return kobj;
 723
 724 }
 725
 726 EXPORT_SYMBOL(get_disk);
 727
 728 void put_disk(struct gendisk *disk)
 729 {
 730         if (disk)
 731                 kobject_put(&disk->dev.kobj);
 732 }
 733
 734 EXPORT_SYMBOL(put_disk);
 735
 736 void set_device_ro(struct block_device *bdev, int flag)
 737 {
 738         if (bdev->bd_contains != bdev)
 739                 bdev->bd_part->policy = flag;
 740         else
 741                 bdev->bd_disk->policy = flag;
 742 }
 743
 744 EXPORT_SYMBOL(set_device_ro);
 745
 746 void set_disk_ro(struct gendisk *disk, int flag)
 747 {
 748         int i;
 749         disk->policy = flag;
 750         for (i = 0; i < disk->minors - 1; i++)
 751                 if (disk->part[i]) disk->part[i]->policy = flag;
 752 }
 753
 754 EXPORT_SYMBOL(set_disk_ro);
 755
 756 int bdev_read_only(struct block_device *bdev)
 757 {
 758         if (!bdev)
 759                 return 0;
 760         else if (bdev->bd_contains != bdev)
 761                 return bdev->bd_part->policy;
 762         else
 763                 return bdev->bd_disk->policy;
 764 }
 765
 766 EXPORT_SYMBOL(bdev_read_only);
 767
 768 int invalidate_partition(struct gendisk *disk, int index)
 769 {
 770         int res = 0;
 771         struct block_device *bdev = bdget_disk(disk, index);
 772         if (bdev) {
 773                 fsync_bdev(bdev);
 774                 res = __invalidate_device(bdev);
 775                 bdput(bdev);
 776         }
 777         return res;
 778 }
 779
 780 EXPORT_SYMBOL(invalidate_partition);