block/genhd.c

   1 /*
   2  *  gendisk handling
   3  */
   4
   5 #include <linux/config.h>
   6 #include <linux/module.h>
   7 #include <linux/fs.h>
   8 #include <linux/genhd.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 #define MAX_PROBE_HASH 255      /* random */
  21
  22 static struct subsystem block_subsys;
  23
  24 static DEFINE_MUTEX(block_subsys_lock);
  25
  26 /*
  27  * Can be deleted altogether. Later.
  28  *
  29  */
  30 static struct blk_major_name {
  31         struct blk_major_name *next;
  32         int major;
  33         char name[16];
  34 } *major_names[MAX_PROBE_HASH];
  35
  36 /* index in the above - for now: assume no multimajor ranges */
  37 static inline int major_to_index(int major)
  38 {
  39         return major % MAX_PROBE_HASH;
  40 }
  41
  42 struct blkdev_info {
  43         int index;
  44         struct blk_major_name *bd;
  45 };
  46
  47 /*
  48  * iterate over a list of blkdev_info structures.  allows
  49  * the major_names array to be iterated over from outside this file
  50  * must be called with the block_subsys_lock held
  51  */
  52 void *get_next_blkdev(void *dev)
  53 {
  54         struct blkdev_info *info;
  55
  56         if (dev == NULL) {
  57                 info = kmalloc(sizeof(*info), GFP_KERNEL);
  58                 if (!info)
  59                         goto out;
  60                 info->index=0;
  61                 info->bd = major_names[info->index];
  62                 if (info->bd)
  63                         goto out;
  64         } else {
  65                 info = dev;
  66         }
  67
  68         while (info->index < ARRAY_SIZE(major_names)) {
  69                 if (info->bd)
  70                         info->bd = info->bd->next;
  71                 if (info->bd)
  72                         goto out;
  73                 /*
  74                  * No devices on this chain, move to the next
  75                  */
  76                 info->index++;
  77                 info->bd = (info->index < ARRAY_SIZE(major_names)) ?
  78                         major_names[info->index] : NULL;
  79                 if (info->bd)
  80                         goto out;
  81         }
  82
  83 out:
  84         return info;
  85 }
  86
  87 void *acquire_blkdev_list(void)
  88 {
  89         mutex_lock(&block_subsys_lock);
  90         return get_next_blkdev(NULL);
  91 }
  92
  93 void release_blkdev_list(void *dev)
  94 {
  95         mutex_unlock(&block_subsys_lock);
  96         kfree(dev);
  97 }
  98
  99
 100 /*
 101  * Count the number of records in the blkdev_list.
 102  * must be called with the block_subsys_lock held
 103  */
 104 int count_blkdev_list(void)
 105 {
 106         struct blk_major_name *n;
 107         int i, count;
 108
 109         count = 0;
 110
 111         for (i = 0; i < ARRAY_SIZE(major_names); i++) {
 112                 for (n = major_names[i]; n; n = n->next)
 113                                 count++;
 114         }
 115
 116         return count;
 117 }
 118
 119 /*
 120  * extract the major and name values from a blkdev_info struct
 121  * passed in as a void to *dev.  Must be called with
 122  * block_subsys_lock held
 123  */
 124 int get_blkdev_info(void *dev, int *major, char **name)
 125 {
 126         struct blkdev_info *info = dev;
 127
 128         if (info->bd == NULL)
 129                 return 1;
 130
 131         *major = info->bd->major;
 132         *name = info->bd->name;
 133         return 0;
 134 }
 135
 136
 137 int register_blkdev(unsigned int major, const char *name)
 138 {
 139         struct blk_major_name **n, *p;
 140         int index, ret = 0;
 141
 142         mutex_lock(&block_subsys_lock);
 143
 144         /* temporary */
 145         if (major == 0) {
 146                 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
 147                         if (major_names[index] == NULL)
 148                                 break;
 149                 }
 150
 151                 if (index == 0) {
 152                         printk("register_blkdev: failed to get major for %s\n",
 153                                name);
 154                         ret = -EBUSY;
 155                         goto out;
 156                 }
 157                 major = index;
 158                 ret = major;
 159         }
 160
 161         p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
 162         if (p == NULL) {
 163                 ret = -ENOMEM;
 164                 goto out;
 165         }
 166
 167         p->major = major;
 168         strlcpy(p->name, name, sizeof(p->name));
 169         p->next = NULL;
 170         index = major_to_index(major);
 171
 172         for (n = &major_names[index]; *n; n = &(*n)->next) {
 173                 if ((*n)->major == major)
 174                         break;
 175         }
 176         if (!*n)
 177                 *n = p;
 178         else
 179                 ret = -EBUSY;
 180
 181         if (ret < 0) {
 182                 printk("register_blkdev: cannot get major %d for %s\n",
 183                        major, name);
 184                 kfree(p);
 185         }
 186 out:
 187         mutex_unlock(&block_subsys_lock);
 188         return ret;
 189 }
 190
 191 EXPORT_SYMBOL(register_blkdev);
 192
 193 /* todo: make void - error printk here */
 194 int unregister_blkdev(unsigned int major, const char *name)
 195 {
 196         struct blk_major_name **n;
 197         struct blk_major_name *p = NULL;
 198         int index = major_to_index(major);
 199         int ret = 0;
 200
 201         mutex_lock(&block_subsys_lock);
 202         for (n = &major_names[index]; *n; n = &(*n)->next)
 203                 if ((*n)->major == major)
 204                         break;
 205         if (!*n || strcmp((*n)->name, name))
 206                 ret = -EINVAL;
 207         else {
 208                 p = *n;
 209                 *n = p->next;
 210         }
 211         mutex_unlock(&block_subsys_lock);
 212         kfree(p);
 213
 214         return ret;
 215 }
 216
 217 EXPORT_SYMBOL(unregister_blkdev);
 218
 219 static struct kobj_map *bdev_map;
 220
 221 /*
 222  * Register device numbers dev..(dev+range-1)
 223  * range must be nonzero
 224  * The hash chain is sorted on range, so that subranges can override.
 225  */
 226 void blk_register_region(dev_t dev, unsigned long range, struct module *module,
 227                          struct kobject *(*probe)(dev_t, int *, void *),
 228                          int (*lock)(dev_t, void *), void *data)
 229 {
 230         kobj_map(bdev_map, dev, range, module, probe, lock, data);
 231 }
 232
 233 EXPORT_SYMBOL(blk_register_region);
 234
 235 void blk_unregister_region(dev_t dev, unsigned long range)
 236 {
 237         kobj_unmap(bdev_map, dev, range);
 238 }
 239
 240 EXPORT_SYMBOL(blk_unregister_region);
 241
 242 static struct kobject *exact_match(dev_t dev, int *part, void *data)
 243 {
 244         struct gendisk *p = data;
 245         return &p->kobj;
 246 }
 247
 248 static int exact_lock(dev_t dev, void *data)
 249 {
 250         struct gendisk *p = data;
 251
 252         if (!get_disk(p))
 253                 return -1;
 254         return 0;
 255 }
 256
 257 /**
 258  * add_disk - add partitioning information to kernel list
 259  * @disk: per-device partitioning information
 260  *
 261  * This function registers the partitioning information in @disk
 262  * with the kernel.
 263  */
 264 void add_disk(struct gendisk *disk)
 265 {
 266         disk->flags |= GENHD_FL_UP;
 267         blk_register_region(MKDEV(disk->major, disk->first_minor),
 268                             disk->minors, NULL, exact_match, exact_lock, disk);
 269         register_disk(disk);
 270         blk_register_queue(disk);
 271 }
 272
 273 EXPORT_SYMBOL(add_disk);
 274 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 275
 276 void unlink_gendisk(struct gendisk *disk)
 277 {
 278         blk_unregister_queue(disk);
 279         blk_unregister_region(MKDEV(disk->major, disk->first_minor),
 280                               disk->minors);
 281 }
 282
 283 #define to_disk(obj) container_of(obj,struct gendisk,kobj)
 284
 285 /**
 286  * get_gendisk - get partitioning information for a given device
 287  * @dev: device to get partitioning information for
 288  *
 289  * This function gets the structure containing partitioning
 290  * information for the given device @dev.
 291  */
 292 struct gendisk *get_gendisk(dev_t dev, int *part)
 293 {
 294         struct kobject *kobj = kobj_lookup(bdev_map, dev, part);
 295         return  kobj ? to_disk(kobj) : NULL;
 296 }
 297
 298 #ifdef CONFIG_PROC_FS
 299 /* iterator */
 300 static void *part_start(struct seq_file *part, loff_t *pos)
 301 {
 302         struct list_head *p;
 303         loff_t l = *pos;
 304
 305         mutex_lock(&block_subsys_lock);
 306         list_for_each(p, &block_subsys.kset.list)
 307                 if (!l--)
 308                         return list_entry(p, struct gendisk, kobj.entry);
 309         return NULL;
 310 }
 311
 312 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 313 {
 314         struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
 315         ++*pos;
 316         return p==&block_subsys.kset.list ? NULL :
 317                 list_entry(p, struct gendisk, kobj.entry);
 318 }
 319
 320 static void part_stop(struct seq_file *part, void *v)
 321 {
 322         mutex_unlock(&block_subsys_lock);
 323 }
 324
 325 static int show_partition(struct seq_file *part, void *v)
 326 {
 327         struct gendisk *sgp = v;
 328         int n;
 329         char buf[BDEVNAME_SIZE];
 330
 331         if (&sgp->kobj.entry == block_subsys.kset.list.next)
 332                 seq_puts(part, "major minor  #blocks  name\n\n");
 333
 334         /* Don't show non-partitionable removeable devices or empty devices */
 335         if (!get_capacity(sgp) ||
 336                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 337                 return 0;
 338         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 339                 return 0;
 340
 341         /* show the full disk and all non-0 size partitions of it */
 342         seq_printf(part, "%4d  %4d %10llu %s\n",
 343                 sgp->major, sgp->first_minor,
 344                 (unsigned long long)get_capacity(sgp) >> 1,
 345                 disk_name(sgp, 0, buf));
 346         for (n = 0; n < sgp->minors - 1; n++) {
 347                 if (!sgp->part[n])
 348                         continue;
 349                 if (sgp->part[n]->nr_sects == 0)
 350                         continue;
 351                 seq_printf(part, "%4d  %4d %10llu %s\n",
 352                         sgp->major, n + 1 + sgp->first_minor,
 353                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 354                         disk_name(sgp, n + 1, buf));
 355         }
 356
 357         return 0;
 358 }
 359
 360 struct seq_operations partitions_op = {
 361         .start =part_start,
 362         .next = part_next,
 363         .stop = part_stop,
 364         .show = show_partition
 365 };
 366 #endif
 367
 368
 369 extern int blk_dev_init(void);
 370
 371 static struct kobject *base_probe(dev_t dev, int *part, void *data)
 372 {
 373         if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
 374                 /* Make old-style 2.4 aliases work */
 375                 request_module("block-major-%d", MAJOR(dev));
 376         return NULL;
 377 }
 378
 379 static int __init genhd_device_init(void)
 380 {
 381         bdev_map = kobj_map_init(base_probe, &block_subsys_lock);
 382         blk_dev_init();
 383         subsystem_register(&block_subsys);
 384         return 0;
 385 }
 386
 387 subsys_initcall(genhd_device_init);
 388
 389
 390
 391 /*
 392  * kobject & sysfs bindings for block devices
 393  */
 394 static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr,
 395                               char *page)
 396 {
 397         struct gendisk *disk = to_disk(kobj);
 398         struct disk_attribute *disk_attr =
 399                 container_of(attr,struct disk_attribute,attr);
 400         ssize_t ret = -EIO;
 401
 402         if (disk_attr->show)
 403                 ret = disk_attr->show(disk,page);
 404         return ret;
 405 }
 406
 407 static ssize_t disk_attr_store(struct kobject * kobj, struct attribute * attr,
 408                                const char *page, size_t count)
 409 {
 410         struct gendisk *disk = to_disk(kobj);
 411         struct disk_attribute *disk_attr =
 412                 container_of(attr,struct disk_attribute,attr);
 413         ssize_t ret = 0;
 414
 415         if (disk_attr->store)
 416                 ret = disk_attr->store(disk, page, count);
 417         return ret;
 418 }
 419
 420 static struct sysfs_ops disk_sysfs_ops = {
 421         .show   = &disk_attr_show,
 422         .store  = &disk_attr_store,
 423 };
 424
 425 static ssize_t disk_uevent_store(struct gendisk * disk,
 426                                  const char *buf, size_t count)
 427 {
 428         kobject_uevent(&disk->kobj, KOBJ_ADD);
 429         return count;
 430 }
 431 static ssize_t disk_dev_read(struct gendisk * disk, char *page)
 432 {
 433         dev_t base = MKDEV(disk->major, disk->first_minor);
 434         return print_dev_t(page, base);
 435 }
 436 static ssize_t disk_range_read(struct gendisk * disk, char *page)
 437 {
 438         return sprintf(page, "%d\n", disk->minors);
 439 }
 440 static ssize_t disk_removable_read(struct gendisk * disk, char *page)
 441 {
 442         return sprintf(page, "%d\n",
 443                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 444
 445 }
 446 static ssize_t disk_size_read(struct gendisk * disk, char *page)
 447 {
 448         return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
 449 }
 450
 451 static ssize_t disk_stats_read(struct gendisk * disk, char *page)
 452 {
 453         preempt_disable();
 454         disk_round_stats(disk);
 455         preempt_enable();
 456         return sprintf(page,
 457                 "%8u %8u %8llu %8u "
 458                 "%8u %8u %8llu %8u "
 459                 "%8u %8u %8u"
 460                 "\n",
 461                 disk_stat_read(disk, ios[READ]),
 462                 disk_stat_read(disk, merges[READ]),
 463                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 464                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 465                 disk_stat_read(disk, ios[WRITE]),
 466                 disk_stat_read(disk, merges[WRITE]),
 467                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 468                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 469                 disk->in_flight,
 470                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 471                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 472 }
 473 static struct disk_attribute disk_attr_uevent = {
 474         .attr = {.name = "uevent", .mode = S_IWUSR },
 475         .store  = disk_uevent_store
 476 };
 477 static struct disk_attribute disk_attr_dev = {
 478         .attr = {.name = "dev", .mode = S_IRUGO },
 479         .show   = disk_dev_read
 480 };
 481 static struct disk_attribute disk_attr_range = {
 482         .attr = {.name = "range", .mode = S_IRUGO },
 483         .show   = disk_range_read
 484 };
 485 static struct disk_attribute disk_attr_removable = {
 486         .attr = {.name = "removable", .mode = S_IRUGO },
 487         .show   = disk_removable_read
 488 };
 489 static struct disk_attribute disk_attr_size = {
 490         .attr = {.name = "size", .mode = S_IRUGO },
 491         .show   = disk_size_read
 492 };
 493 static struct disk_attribute disk_attr_stat = {
 494         .attr = {.name = "stat", .mode = S_IRUGO },
 495         .show   = disk_stats_read
 496 };
 497
 498 static struct attribute * default_attrs[] = {
 499         &disk_attr_uevent.attr,
 500         &disk_attr_dev.attr,
 501         &disk_attr_range.attr,
 502         &disk_attr_removable.attr,
 503         &disk_attr_size.attr,
 504         &disk_attr_stat.attr,
 505         NULL,
 506 };
 507
 508 static void disk_release(struct kobject * kobj)
 509 {
 510         struct gendisk *disk = to_disk(kobj);
 511         kfree(disk->random);
 512         kfree(disk->part);
 513         free_disk_stats(disk);
 514         kfree(disk);
 515 }
 516
 517 static struct kobj_type ktype_block = {
 518         .release        = disk_release,
 519         .sysfs_ops      = &disk_sysfs_ops,
 520         .default_attrs  = default_attrs,
 521 };
 522
 523 extern struct kobj_type ktype_part;
 524
 525 static int block_uevent_filter(struct kset *kset, struct kobject *kobj)
 526 {
 527         struct kobj_type *ktype = get_ktype(kobj);
 528
 529         return ((ktype == &ktype_block) || (ktype == &ktype_part));
 530 }
 531
 532 static int block_uevent(struct kset *kset, struct kobject *kobj, char **envp,
 533                          int num_envp, char *buffer, int buffer_size)
 534 {
 535         struct kobj_type *ktype = get_ktype(kobj);
 536         struct device *physdev;
 537         struct gendisk *disk;
 538         struct hd_struct *part;
 539         int length = 0;
 540         int i = 0;
 541
 542         if (ktype == &ktype_block) {
 543                 disk = container_of(kobj, struct gendisk, kobj);
 544                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 545                                &length, "MINOR=%u", disk->first_minor);
 546         } else if (ktype == &ktype_part) {
 547                 disk = container_of(kobj->parent, struct gendisk, kobj);
 548                 part = container_of(kobj, struct hd_struct, kobj);
 549                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 550                                &length, "MINOR=%u",
 551                                disk->first_minor + part->partno);
 552         } else
 553                 return 0;
 554
 555         add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
 556                        "MAJOR=%u", disk->major);
 557
 558         /* add physical device, backing this device  */
 559         physdev = disk->driverfs_dev;
 560         if (physdev) {
 561                 char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL);
 562
 563                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 564                                &length, "PHYSDEVPATH=%s", path);
 565                 kfree(path);
 566
 567                 if (physdev->bus)
 568                         add_uevent_var(envp, num_envp, &i,
 569                                        buffer, buffer_size, &length,
 570                                        "PHYSDEVBUS=%s",
 571                                        physdev->bus->name);
 572
 573                 if (physdev->driver)
 574                         add_uevent_var(envp, num_envp, &i,
 575                                        buffer, buffer_size, &length,
 576                                        "PHYSDEVDRIVER=%s",
 577                                        physdev->driver->name);
 578         }
 579
 580         /* terminate, set to next free slot, shrink available space */
 581         envp[i] = NULL;
 582         envp = &envp[i];
 583         num_envp -= i;
 584         buffer = &buffer[length];
 585         buffer_size -= length;
 586
 587         return 0;
 588 }
 589
 590 static struct kset_uevent_ops block_uevent_ops = {
 591         .filter         = block_uevent_filter,
 592         .uevent         = block_uevent,
 593 };
 594
 595 /* declare block_subsys. */
 596 static decl_subsys(block, &ktype_block, &block_uevent_ops);
 597
 598
 599 /*
 600  * aggregate disk stat collector.  Uses the same stats that the sysfs
 601  * entries do, above, but makes them available through one seq_file.
 602  * Watching a few disks may be efficient through sysfs, but watching
 603  * all of them will be more efficient through this interface.
 604  *
 605  * The output looks suspiciously like /proc/partitions with a bunch of
 606  * extra fields.
 607  */
 608
 609 /* iterator */
 610 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 611 {
 612         loff_t k = *pos;
 613         struct list_head *p;
 614
 615         mutex_lock(&block_subsys_lock);
 616         list_for_each(p, &block_subsys.kset.list)
 617                 if (!k--)
 618                         return list_entry(p, struct gendisk, kobj.entry);
 619         return NULL;
 620 }
 621
 622 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 623 {
 624         struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
 625         ++*pos;
 626         return p==&block_subsys.kset.list ? NULL :
 627                 list_entry(p, struct gendisk, kobj.entry);
 628 }
 629
 630 static void diskstats_stop(struct seq_file *part, void *v)
 631 {
 632         mutex_unlock(&block_subsys_lock);
 633 }
 634
 635 static int diskstats_show(struct seq_file *s, void *v)
 636 {
 637         struct gendisk *gp = v;
 638         char buf[BDEVNAME_SIZE];
 639         int n = 0;
 640
 641         /*
 642         if (&sgp->kobj.entry == block_subsys.kset.list.next)
 643                 seq_puts(s,     "major minor name"
 644                                 "     rio rmerge rsect ruse wio wmerge "
 645                                 "wsect wuse running use aveq"
 646                                 "\n\n");
 647         */
 648
 649         preempt_disable();
 650         disk_round_stats(gp);
 651         preempt_enable();
 652         seq_printf(s, "%4d %4d %s %u %u %llu %u %u %u %llu %u %u %u %u\n",
 653                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 654                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 655                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 656                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 657                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 658                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 659                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 660                 gp->in_flight,
 661                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 662                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 663
 664         /* now show all non-0 size partitions of it */
 665         for (n = 0; n < gp->minors - 1; n++) {
 666                 struct hd_struct *hd = gp->part[n];
 667
 668                 if (hd && hd->nr_sects)
 669                         seq_printf(s, "%4d %4d %s %u %u %u %u\n",
 670                                 gp->major, n + gp->first_minor + 1,
 671                                 disk_name(gp, n + 1, buf),
 672                                 hd->ios[0], hd->sectors[0],
 673                                 hd->ios[1], hd->sectors[1]);
 674         }
 675
 676         return 0;
 677 }
 678
 679 struct seq_operations diskstats_op = {
 680         .start  = diskstats_start,
 681         .next   = diskstats_next,
 682         .stop   = diskstats_stop,
 683         .show   = diskstats_show
 684 };
 685
 686 struct gendisk *alloc_disk(int minors)
 687 {
 688         return alloc_disk_node(minors, -1);
 689 }
 690
 691 struct gendisk *alloc_disk_node(int minors, int node_id)
 692 {
 693         struct gendisk *disk;
 694
 695         disk = kmalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
 696         if (disk) {
 697                 memset(disk, 0, sizeof(struct gendisk));
 698                 if (!init_disk_stats(disk)) {
 699                         kfree(disk);
 700                         return NULL;
 701                 }
 702                 if (minors > 1) {
 703                         int size = (minors - 1) * sizeof(struct hd_struct *);
 704                         disk->part = kmalloc_node(size, GFP_KERNEL, node_id);
 705                         if (!disk->part) {
 706                                 kfree(disk);
 707                                 return NULL;
 708                         }
 709                         memset(disk->part, 0, size);
 710                 }
 711                 disk->minors = minors;
 712                 kobj_set_kset_s(disk,block_subsys);
 713                 kobject_init(&disk->kobj);
 714                 rand_initialize_disk(disk);
 715         }
 716         return disk;
 717 }
 718
 719 EXPORT_SYMBOL(alloc_disk);
 720 EXPORT_SYMBOL(alloc_disk_node);
 721
 722 struct kobject *get_disk(struct gendisk *disk)
 723 {
 724         struct module *owner;
 725         struct kobject *kobj;
 726
 727         if (!disk->fops)
 728                 return NULL;
 729         owner = disk->fops->owner;
 730         if (owner && !try_module_get(owner))
 731                 return NULL;
 732         kobj = kobject_get(&disk->kobj);
 733         if (kobj == NULL) {
 734                 module_put(owner);
 735                 return NULL;
 736         }
 737         return kobj;
 738
 739 }
 740
 741 EXPORT_SYMBOL(get_disk);
 742
 743 void put_disk(struct gendisk *disk)
 744 {
 745         if (disk)
 746                 kobject_put(&disk->kobj);
 747 }
 748
 749 EXPORT_SYMBOL(put_disk);
 750
 751 void set_device_ro(struct block_device *bdev, int flag)
 752 {
 753         if (bdev->bd_contains != bdev)
 754                 bdev->bd_part->policy = flag;
 755         else
 756                 bdev->bd_disk->policy = flag;
 757 }
 758
 759 EXPORT_SYMBOL(set_device_ro);
 760
 761 void set_disk_ro(struct gendisk *disk, int flag)
 762 {
 763         int i;
 764         disk->policy = flag;
 765         for (i = 0; i < disk->minors - 1; i++)
 766                 if (disk->part[i]) disk->part[i]->policy = flag;
 767 }
 768
 769 EXPORT_SYMBOL(set_disk_ro);
 770
 771 int bdev_read_only(struct block_device *bdev)
 772 {
 773         if (!bdev)
 774                 return 0;
 775         else if (bdev->bd_contains != bdev)
 776                 return bdev->bd_part->policy;
 777         else
 778                 return bdev->bd_disk->policy;
 779 }
 780
 781 EXPORT_SYMBOL(bdev_read_only);
 782
 783 int invalidate_partition(struct gendisk *disk, int index)
 784 {
 785         int res = 0;
 786         struct block_device *bdev = bdget_disk(disk, index);
 787         if (bdev) {
 788                 fsync_bdev(bdev);
 789                 res = __invalidate_device(bdev);
 790                 bdput(bdev);
 791         }
 792         return res;
 793 }
 794
 795 EXPORT_SYMBOL(invalidate_partition);