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 = class_register(&block_class);
 374         if (unlikely(error))
 375                 return error;
 376         bdev_map = kobj_map_init(base_probe, &block_class_lock);
 377         blk_dev_init();
 378
 379 #ifndef CONFIG_SYSFS_DEPRECATED
 380         /* create top-level block dir */
 381         block_depr = kobject_create_and_add("block", NULL);
 382 #endif
 383         return 0;
 384 }
 385
 386 subsys_initcall(genhd_device_init);
 387
 388 static ssize_t disk_range_show(struct device *dev,
 389                                struct device_attribute *attr, char *buf)
 390 {
 391         struct gendisk *disk = dev_to_disk(dev);
 392
 393         return sprintf(buf, "%d\n", disk->minors);
 394 }
 395
 396 static ssize_t disk_removable_show(struct device *dev,
 397                                    struct device_attribute *attr, char *buf)
 398 {
 399         struct gendisk *disk = dev_to_disk(dev);
 400
 401         return sprintf(buf, "%d\n",
 402                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 403 }
 404
 405 static ssize_t disk_ro_show(struct device *dev,
 406                                    struct device_attribute *attr, char *buf)
 407 {
 408         struct gendisk *disk = dev_to_disk(dev);
 409
 410         return sprintf(buf, "%d\n", disk->policy ? 1 : 0);
 411 }
 412
 413 static ssize_t disk_size_show(struct device *dev,
 414                               struct device_attribute *attr, char *buf)
 415 {
 416         struct gendisk *disk = dev_to_disk(dev);
 417
 418         return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
 419 }
 420
 421 static ssize_t disk_capability_show(struct device *dev,
 422                                     struct device_attribute *attr, char *buf)
 423 {
 424         struct gendisk *disk = dev_to_disk(dev);
 425
 426         return sprintf(buf, "%x\n", disk->flags);
 427 }
 428
 429 static ssize_t disk_stat_show(struct device *dev,
 430                               struct device_attribute *attr, char *buf)
 431 {
 432         struct gendisk *disk = dev_to_disk(dev);
 433
 434         preempt_disable();
 435         disk_round_stats(disk);
 436         preempt_enable();
 437         return sprintf(buf,
 438                 "%8lu %8lu %8llu %8u "
 439                 "%8lu %8lu %8llu %8u "
 440                 "%8u %8u %8u"
 441                 "\n",
 442                 disk_stat_read(disk, ios[READ]),
 443                 disk_stat_read(disk, merges[READ]),
 444                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 445                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 446                 disk_stat_read(disk, ios[WRITE]),
 447                 disk_stat_read(disk, merges[WRITE]),
 448                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 449                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 450                 disk->in_flight,
 451                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 452                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 453 }
 454
 455 #ifdef CONFIG_FAIL_MAKE_REQUEST
 456 static ssize_t disk_fail_show(struct device *dev,
 457                               struct device_attribute *attr, char *buf)
 458 {
 459         struct gendisk *disk = dev_to_disk(dev);
 460
 461         return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 462 }
 463
 464 static ssize_t disk_fail_store(struct device *dev,
 465                                struct device_attribute *attr,
 466                                const char *buf, size_t count)
 467 {
 468         struct gendisk *disk = dev_to_disk(dev);
 469         int i;
 470
 471         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 472                 if (i == 0)
 473                         disk->flags &= ~GENHD_FL_FAIL;
 474                 else
 475                         disk->flags |= GENHD_FL_FAIL;
 476         }
 477
 478         return count;
 479 }
 480
 481 #endif
 482
 483 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 484 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
 485 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
 486 static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
 487 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
 488 static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
 489 #ifdef CONFIG_FAIL_MAKE_REQUEST
 490 static struct device_attribute dev_attr_fail =
 491         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
 492 #endif
 493
 494 static struct attribute *disk_attrs[] = {
 495         &dev_attr_range.attr,
 496         &dev_attr_removable.attr,
 497         &dev_attr_ro.attr,
 498         &dev_attr_size.attr,
 499         &dev_attr_capability.attr,
 500         &dev_attr_stat.attr,
 501 #ifdef CONFIG_FAIL_MAKE_REQUEST
 502         &dev_attr_fail.attr,
 503 #endif
 504         NULL
 505 };
 506
 507 static struct attribute_group disk_attr_group = {
 508         .attrs = disk_attrs,
 509 };
 510
 511 static struct attribute_group *disk_attr_groups[] = {
 512         &disk_attr_group,
 513         NULL
 514 };
 515
 516 static void disk_release(struct device *dev)
 517 {
 518         struct gendisk *disk = dev_to_disk(dev);
 519
 520         kfree(disk->random);
 521         kfree(disk->part);
 522         free_disk_stats(disk);
 523         kfree(disk);
 524 }
 525 struct class block_class = {
 526         .name           = "block",
 527 };
 528
 529 static struct device_type disk_type = {
 530         .name           = "disk",
 531         .groups         = disk_attr_groups,
 532         .release        = disk_release,
 533 };
 534
 535 /*
 536  * aggregate disk stat collector.  Uses the same stats that the sysfs
 537  * entries do, above, but makes them available through one seq_file.
 538  *
 539  * The output looks suspiciously like /proc/partitions with a bunch of
 540  * extra fields.
 541  */
 542
 543 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 544 {
 545         loff_t k = *pos;
 546         struct device *dev;
 547
 548         mutex_lock(&block_class_lock);
 549         list_for_each_entry(dev, &block_class.devices, node) {
 550                 if (dev->type != &disk_type)
 551                         continue;
 552                 if (!k--)
 553                         return dev_to_disk(dev);
 554         }
 555         return NULL;
 556 }
 557
 558 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 559 {
 560         struct gendisk *gp = v;
 561         struct device *dev;
 562
 563         ++*pos;
 564         list_for_each_entry(dev, &gp->dev.node, node) {
 565                 if (&dev->node == &block_class.devices)
 566                         return NULL;
 567                 if (dev->type == &disk_type)
 568                         return dev_to_disk(dev);
 569         }
 570         return NULL;
 571 }
 572
 573 static void diskstats_stop(struct seq_file *part, void *v)
 574 {
 575         mutex_unlock(&block_class_lock);
 576 }
 577
 578 static int diskstats_show(struct seq_file *s, void *v)
 579 {
 580         struct gendisk *gp = v;
 581         char buf[BDEVNAME_SIZE];
 582         int n = 0;
 583
 584         /*
 585         if (&gp->dev.kobj.entry == block_class.devices.next)
 586                 seq_puts(s,     "major minor name"
 587                                 "     rio rmerge rsect ruse wio wmerge "
 588                                 "wsect wuse running use aveq"
 589                                 "\n\n");
 590         */
 591
 592         preempt_disable();
 593         disk_round_stats(gp);
 594         preempt_enable();
 595         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 596                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 597                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 598                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 599                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 600                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 601                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 602                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 603                 gp->in_flight,
 604                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 605                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 606
 607         /* now show all non-0 size partitions of it */
 608         for (n = 0; n < gp->minors - 1; n++) {
 609                 struct hd_struct *hd = gp->part[n];
 610
 611                 if (!hd || !hd->nr_sects)
 612                         continue;
 613
 614                 preempt_disable();
 615                 part_round_stats(hd);
 616                 preempt_enable();
 617                 seq_printf(s, "%4d %4d %s %lu %lu %llu "
 618                            "%u %lu %lu %llu %u %u %u %u\n",
 619                            gp->major, n + gp->first_minor + 1,
 620                            disk_name(gp, n + 1, buf),
 621                            part_stat_read(hd, ios[0]),
 622                            part_stat_read(hd, merges[0]),
 623                            (unsigned long long)part_stat_read(hd, sectors[0]),
 624                            jiffies_to_msecs(part_stat_read(hd, ticks[0])),
 625                            part_stat_read(hd, ios[1]),
 626                            part_stat_read(hd, merges[1]),
 627                            (unsigned long long)part_stat_read(hd, sectors[1]),
 628                            jiffies_to_msecs(part_stat_read(hd, ticks[1])),
 629                            hd->in_flight,
 630                            jiffies_to_msecs(part_stat_read(hd, io_ticks)),
 631                            jiffies_to_msecs(part_stat_read(hd, time_in_queue))
 632                         );
 633         }
 634
 635         return 0;
 636 }
 637
 638 const struct seq_operations diskstats_op = {
 639         .start  = diskstats_start,
 640         .next   = diskstats_next,
 641         .stop   = diskstats_stop,
 642         .show   = diskstats_show
 643 };
 644
 645 static void media_change_notify_thread(struct work_struct *work)
 646 {
 647         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 648         char event[] = "MEDIA_CHANGE=1";
 649         char *envp[] = { event, NULL };
 650
 651         /*
 652          * set enviroment vars to indicate which event this is for
 653          * so that user space will know to go check the media status.
 654          */
 655         kobject_uevent_env(&gd->dev.kobj, KOBJ_CHANGE, envp);
 656         put_device(gd->driverfs_dev);
 657 }
 658
 659 #if 0
 660 void genhd_media_change_notify(struct gendisk *disk)
 661 {
 662         get_device(disk->driverfs_dev);
 663         schedule_work(&disk->async_notify);
 664 }
 665 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 666 #endif  /*  0  */
 667
 668 dev_t blk_lookup_devt(const char *name, int part)
 669 {
 670         struct device *dev;
 671         dev_t devt = MKDEV(0, 0);
 672
 673         mutex_lock(&block_class_lock);
 674         list_for_each_entry(dev, &block_class.devices, node) {
 675                 if (dev->type != &disk_type)
 676                         continue;
 677                 if (strcmp(dev->bus_id, name) == 0) {
 678                         struct gendisk *disk = dev_to_disk(dev);
 679
 680                         if (part < disk->minors)
 681                                 devt = MKDEV(MAJOR(dev->devt),
 682                                              MINOR(dev->devt) + part);
 683                         break;
 684                 }
 685         }
 686         mutex_unlock(&block_class_lock);
 687
 688         return devt;
 689 }
 690 EXPORT_SYMBOL(blk_lookup_devt);
 691
 692 struct gendisk *alloc_disk(int minors)
 693 {
 694         return alloc_disk_node(minors, -1);
 695 }
 696
 697 struct gendisk *alloc_disk_node(int minors, int node_id)
 698 {
 699         struct gendisk *disk;
 700
 701         disk = kmalloc_node(sizeof(struct gendisk),
 702                                 GFP_KERNEL | __GFP_ZERO, node_id);
 703         if (disk) {
 704                 if (!init_disk_stats(disk)) {
 705                         kfree(disk);
 706                         return NULL;
 707                 }
 708                 if (minors > 1) {
 709                         int size = (minors - 1) * sizeof(struct hd_struct *);
 710                         disk->part = kmalloc_node(size,
 711                                 GFP_KERNEL | __GFP_ZERO, node_id);
 712                         if (!disk->part) {
 713                                 free_disk_stats(disk);
 714                                 kfree(disk);
 715                                 return NULL;
 716                         }
 717                 }
 718                 disk->minors = minors;
 719                 rand_initialize_disk(disk);
 720                 disk->dev.class = &block_class;
 721                 disk->dev.type = &disk_type;
 722                 device_initialize(&disk->dev);
 723                 INIT_WORK(&disk->async_notify,
 724                         media_change_notify_thread);
 725         }
 726         return disk;
 727 }
 728
 729 EXPORT_SYMBOL(alloc_disk);
 730 EXPORT_SYMBOL(alloc_disk_node);
 731
 732 struct kobject *get_disk(struct gendisk *disk)
 733 {
 734         struct module *owner;
 735         struct kobject *kobj;
 736
 737         if (!disk->fops)
 738                 return NULL;
 739         owner = disk->fops->owner;
 740         if (owner && !try_module_get(owner))
 741                 return NULL;
 742         kobj = kobject_get(&disk->dev.kobj);
 743         if (kobj == NULL) {
 744                 module_put(owner);
 745                 return NULL;
 746         }
 747         return kobj;
 748
 749 }
 750
 751 EXPORT_SYMBOL(get_disk);
 752
 753 void put_disk(struct gendisk *disk)
 754 {
 755         if (disk)
 756                 kobject_put(&disk->dev.kobj);
 757 }
 758
 759 EXPORT_SYMBOL(put_disk);
 760
 761 void set_device_ro(struct block_device *bdev, int flag)
 762 {
 763         if (bdev->bd_contains != bdev)
 764                 bdev->bd_part->policy = flag;
 765         else
 766                 bdev->bd_disk->policy = flag;
 767 }
 768
 769 EXPORT_SYMBOL(set_device_ro);
 770
 771 void set_disk_ro(struct gendisk *disk, int flag)
 772 {
 773         int i;
 774         disk->policy = flag;
 775         for (i = 0; i < disk->minors - 1; i++)
 776                 if (disk->part[i]) disk->part[i]->policy = flag;
 777 }
 778
 779 EXPORT_SYMBOL(set_disk_ro);
 780
 781 int bdev_read_only(struct block_device *bdev)
 782 {
 783         if (!bdev)
 784                 return 0;
 785         else if (bdev->bd_contains != bdev)
 786                 return bdev->bd_part->policy;
 787         else
 788                 return bdev->bd_disk->policy;
 789 }
 790
 791 EXPORT_SYMBOL(bdev_read_only);
 792
 793 int invalidate_partition(struct gendisk *disk, int index)
 794 {
 795         int res = 0;
 796         struct block_device *bdev = bdget_disk(disk, index);
 797         if (bdev) {
 798                 fsync_bdev(bdev);
 799                 res = __invalidate_device(bdev);
 800                 bdput(bdev);
 801         }
 802         return res;
 803 }
 804
 805 EXPORT_SYMBOL(invalidate_partition);