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