block/genhd.c

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