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         class_register(&block_class);
 364         bdev_map = kobj_map_init(base_probe, &block_class_lock);
 365         blk_dev_init();
 366
 367 #ifndef CONFIG_SYSFS_DEPRECATED
 368         /* create top-level block dir */
 369         block_depr = kobject_create_and_add("block", NULL);
 370 #endif
 371         return 0;
 372 }
 373
 374 subsys_initcall(genhd_device_init);
 375
 376 static ssize_t disk_range_show(struct device *dev,
 377                                struct device_attribute *attr, char *buf)
 378 {
 379         struct gendisk *disk = dev_to_disk(dev);
 380
 381         return sprintf(buf, "%d\n", disk->minors);
 382 }
 383
 384 static ssize_t disk_removable_show(struct device *dev,
 385                                    struct device_attribute *attr, char *buf)
 386 {
 387         struct gendisk *disk = dev_to_disk(dev);
 388
 389         return sprintf(buf, "%d\n",
 390                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 391 }
 392
 393 static ssize_t disk_size_show(struct device *dev,
 394                               struct device_attribute *attr, char *buf)
 395 {
 396         struct gendisk *disk = dev_to_disk(dev);
 397
 398         return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
 399 }
 400
 401 static ssize_t disk_capability_show(struct device *dev,
 402                                     struct device_attribute *attr, char *buf)
 403 {
 404         struct gendisk *disk = dev_to_disk(dev);
 405
 406         return sprintf(buf, "%x\n", disk->flags);
 407 }
 408
 409 static ssize_t disk_stat_show(struct device *dev,
 410                               struct device_attribute *attr, char *buf)
 411 {
 412         struct gendisk *disk = dev_to_disk(dev);
 413
 414         preempt_disable();
 415         disk_round_stats(disk);
 416         preempt_enable();
 417         return sprintf(buf,
 418                 "%8lu %8lu %8llu %8u "
 419                 "%8lu %8lu %8llu %8u "
 420                 "%8u %8u %8u"
 421                 "\n",
 422                 disk_stat_read(disk, ios[READ]),
 423                 disk_stat_read(disk, merges[READ]),
 424                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 425                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 426                 disk_stat_read(disk, ios[WRITE]),
 427                 disk_stat_read(disk, merges[WRITE]),
 428                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 429                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 430                 disk->in_flight,
 431                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 432                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 433 }
 434
 435 #ifdef CONFIG_FAIL_MAKE_REQUEST
 436 static ssize_t disk_fail_show(struct device *dev,
 437                               struct device_attribute *attr, char *buf)
 438 {
 439         struct gendisk *disk = dev_to_disk(dev);
 440
 441         return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 442 }
 443
 444 static ssize_t disk_fail_store(struct device *dev,
 445                                struct device_attribute *attr,
 446                                const char *buf, size_t count)
 447 {
 448         struct gendisk *disk = dev_to_disk(dev);
 449         int i;
 450
 451         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 452                 if (i == 0)
 453                         disk->flags &= ~GENHD_FL_FAIL;
 454                 else
 455                         disk->flags |= GENHD_FL_FAIL;
 456         }
 457
 458         return count;
 459 }
 460
 461 #endif
 462
 463 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 464 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
 465 static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
 466 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
 467 static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
 468 #ifdef CONFIG_FAIL_MAKE_REQUEST
 469 static struct device_attribute dev_attr_fail =
 470         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
 471 #endif
 472
 473 static struct attribute *disk_attrs[] = {
 474         &dev_attr_range.attr,
 475         &dev_attr_removable.attr,
 476         &dev_attr_size.attr,
 477         &dev_attr_capability.attr,
 478         &dev_attr_stat.attr,
 479 #ifdef CONFIG_FAIL_MAKE_REQUEST
 480         &dev_attr_fail.attr,
 481 #endif
 482         NULL
 483 };
 484
 485 static struct attribute_group disk_attr_group = {
 486         .attrs = disk_attrs,
 487 };
 488
 489 static struct attribute_group *disk_attr_groups[] = {
 490         &disk_attr_group,
 491         NULL
 492 };
 493
 494 static void disk_release(struct device *dev)
 495 {
 496         struct gendisk *disk = dev_to_disk(dev);
 497
 498         kfree(disk->random);
 499         kfree(disk->part);
 500         free_disk_stats(disk);
 501         kfree(disk);
 502 }
 503 struct class block_class = {
 504         .name           = "block",
 505 };
 506
 507 static struct device_type disk_type = {
 508         .name           = "disk",
 509         .groups         = disk_attr_groups,
 510         .release        = disk_release,
 511 };
 512
 513 /*
 514  * aggregate disk stat collector.  Uses the same stats that the sysfs
 515  * entries do, above, but makes them available through one seq_file.
 516  *
 517  * The output looks suspiciously like /proc/partitions with a bunch of
 518  * extra fields.
 519  */
 520
 521 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 522 {
 523         loff_t k = *pos;
 524         struct device *dev;
 525
 526         mutex_lock(&block_class_lock);
 527         list_for_each_entry(dev, &block_class.devices, node) {
 528                 if (dev->type != &disk_type)
 529                         continue;
 530                 if (!k--)
 531                         return dev_to_disk(dev);
 532         }
 533         return NULL;
 534 }
 535
 536 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 537 {
 538         struct gendisk *gp = v;
 539         struct device *dev;
 540
 541         ++*pos;
 542         list_for_each_entry(dev, &gp->dev.node, node) {
 543                 if (&dev->node == &block_class.devices)
 544                         return NULL;
 545                 if (dev->type == &disk_type)
 546                         return dev_to_disk(dev);
 547         }
 548         return NULL;
 549 }
 550
 551 static void diskstats_stop(struct seq_file *part, void *v)
 552 {
 553         mutex_unlock(&block_class_lock);
 554 }
 555
 556 static int diskstats_show(struct seq_file *s, void *v)
 557 {
 558         struct gendisk *gp = v;
 559         char buf[BDEVNAME_SIZE];
 560         int n = 0;
 561
 562         /*
 563         if (&gp->dev.kobj.entry == block_class.devices.next)
 564                 seq_puts(s,     "major minor name"
 565                                 "     rio rmerge rsect ruse wio wmerge "
 566                                 "wsect wuse running use aveq"
 567                                 "\n\n");
 568         */
 569
 570         preempt_disable();
 571         disk_round_stats(gp);
 572         preempt_enable();
 573         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 574                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 575                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 576                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 577                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 578                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 579                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 580                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 581                 gp->in_flight,
 582                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 583                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 584
 585         /* now show all non-0 size partitions of it */
 586         for (n = 0; n < gp->minors - 1; n++) {
 587                 struct hd_struct *hd = gp->part[n];
 588
 589                 if (!hd || !hd->nr_sects)
 590                         continue;
 591
 592                 preempt_disable();
 593                 part_round_stats(hd);
 594                 preempt_enable();
 595                 seq_printf(s, "%4d %4d %s %lu %lu %llu "
 596                            "%u %lu %lu %llu %u %u %u %u\n",
 597                            gp->major, n + gp->first_minor + 1,
 598                            disk_name(gp, n + 1, buf),
 599                            part_stat_read(hd, ios[0]),
 600                            part_stat_read(hd, merges[0]),
 601                            (unsigned long long)part_stat_read(hd, sectors[0]),
 602                            jiffies_to_msecs(part_stat_read(hd, ticks[0])),
 603                            part_stat_read(hd, ios[1]),
 604                            part_stat_read(hd, merges[1]),
 605                            (unsigned long long)part_stat_read(hd, sectors[1]),
 606                            jiffies_to_msecs(part_stat_read(hd, ticks[1])),
 607                            hd->in_flight,
 608                            jiffies_to_msecs(part_stat_read(hd, io_ticks)),
 609                            jiffies_to_msecs(part_stat_read(hd, time_in_queue))
 610                         );
 611         }
 612
 613         return 0;
 614 }
 615
 616 const struct seq_operations diskstats_op = {
 617         .start  = diskstats_start,
 618         .next   = diskstats_next,
 619         .stop   = diskstats_stop,
 620         .show   = diskstats_show
 621 };
 622
 623 static void media_change_notify_thread(struct work_struct *work)
 624 {
 625         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 626         char event[] = "MEDIA_CHANGE=1";
 627         char *envp[] = { event, NULL };
 628
 629         /*
 630          * set enviroment vars to indicate which event this is for
 631          * so that user space will know to go check the media status.
 632          */
 633         kobject_uevent_env(&gd->dev.kobj, KOBJ_CHANGE, envp);
 634         put_device(gd->driverfs_dev);
 635 }
 636
 637 #if 0
 638 void genhd_media_change_notify(struct gendisk *disk)
 639 {
 640         get_device(disk->driverfs_dev);
 641         schedule_work(&disk->async_notify);
 642 }
 643 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 644 #endif  /*  0  */
 645
 646 dev_t blk_lookup_devt(const char *name)
 647 {
 648         struct device *dev;
 649         dev_t devt = MKDEV(0, 0);
 650
 651         mutex_lock(&block_class_lock);
 652         list_for_each_entry(dev, &block_class.devices, node) {
 653                 if (strcmp(dev->bus_id, name) == 0) {
 654                         devt = dev->devt;
 655                         break;
 656                 }
 657         }
 658         mutex_unlock(&block_class_lock);
 659
 660         return devt;
 661 }
 662
 663 EXPORT_SYMBOL(blk_lookup_devt);
 664
 665 struct gendisk *alloc_disk(int minors)
 666 {
 667         return alloc_disk_node(minors, -1);
 668 }
 669
 670 struct gendisk *alloc_disk_node(int minors, int node_id)
 671 {
 672         struct gendisk *disk;
 673
 674         disk = kmalloc_node(sizeof(struct gendisk),
 675                                 GFP_KERNEL | __GFP_ZERO, node_id);
 676         if (disk) {
 677                 if (!init_disk_stats(disk)) {
 678                         kfree(disk);
 679                         return NULL;
 680                 }
 681                 if (minors > 1) {
 682                         int size = (minors - 1) * sizeof(struct hd_struct *);
 683                         disk->part = kmalloc_node(size,
 684                                 GFP_KERNEL | __GFP_ZERO, node_id);
 685                         if (!disk->part) {
 686                                 free_disk_stats(disk);
 687                                 kfree(disk);
 688                                 return NULL;
 689                         }
 690                 }
 691                 disk->minors = minors;
 692                 rand_initialize_disk(disk);
 693                 disk->dev.class = &block_class;
 694                 disk->dev.type = &disk_type;
 695                 device_initialize(&disk->dev);
 696                 INIT_WORK(&disk->async_notify,
 697                         media_change_notify_thread);
 698         }
 699         return disk;
 700 }
 701
 702 EXPORT_SYMBOL(alloc_disk);
 703 EXPORT_SYMBOL(alloc_disk_node);
 704
 705 struct kobject *get_disk(struct gendisk *disk)
 706 {
 707         struct module *owner;
 708         struct kobject *kobj;
 709
 710         if (!disk->fops)
 711                 return NULL;
 712         owner = disk->fops->owner;
 713         if (owner && !try_module_get(owner))
 714                 return NULL;
 715         kobj = kobject_get(&disk->dev.kobj);
 716         if (kobj == NULL) {
 717                 module_put(owner);
 718                 return NULL;
 719         }
 720         return kobj;
 721
 722 }
 723
 724 EXPORT_SYMBOL(get_disk);
 725
 726 void put_disk(struct gendisk *disk)
 727 {
 728         if (disk)
 729                 kobject_put(&disk->dev.kobj);
 730 }
 731
 732 EXPORT_SYMBOL(put_disk);
 733
 734 void set_device_ro(struct block_device *bdev, int flag)
 735 {
 736         if (bdev->bd_contains != bdev)
 737                 bdev->bd_part->policy = flag;
 738         else
 739                 bdev->bd_disk->policy = flag;
 740 }
 741
 742 EXPORT_SYMBOL(set_device_ro);
 743
 744 void set_disk_ro(struct gendisk *disk, int flag)
 745 {
 746         int i;
 747         disk->policy = flag;
 748         for (i = 0; i < disk->minors - 1; i++)
 749                 if (disk->part[i]) disk->part[i]->policy = flag;
 750 }
 751
 752 EXPORT_SYMBOL(set_disk_ro);
 753
 754 int bdev_read_only(struct block_device *bdev)
 755 {
 756         if (!bdev)
 757                 return 0;
 758         else if (bdev->bd_contains != bdev)
 759                 return bdev->bd_part->policy;
 760         else
 761                 return bdev->bd_disk->policy;
 762 }
 763
 764 EXPORT_SYMBOL(bdev_read_only);
 765
 766 int invalidate_partition(struct gendisk *disk, int index)
 767 {
 768         int res = 0;
 769         struct block_device *bdev = bdget_disk(disk, index);
 770         if (bdev) {
 771                 fsync_bdev(bdev);
 772                 res = __invalidate_device(bdev);
 773                 bdput(bdev);
 774         }
 775         return res;
 776 }
 777
 778 EXPORT_SYMBOL(invalidate_partition);