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         int retval;
 187
 188         disk->flags |= GENHD_FL_UP;
 189         blk_register_region(MKDEV(disk->major, disk->first_minor),
 190                             disk->minors, NULL, exact_match, exact_lock, disk);
 191         register_disk(disk);
 192         blk_register_queue(disk);
 193         blk_register_filter(disk);
 194
 195         bdi = &disk->queue->backing_dev_info;
 196         bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor));
 197         retval = sysfs_create_link(&disk->dev.kobj, &bdi->dev->kobj, "bdi");
 198         WARN_ON(retval);
 199 }
 200
 201 EXPORT_SYMBOL(add_disk);
 202 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 203
 204 void unlink_gendisk(struct gendisk *disk)
 205 {
 206         blk_unregister_filter(disk);
 207         sysfs_remove_link(&disk->dev.kobj, "bdi");
 208         bdi_unregister(&disk->queue->backing_dev_info);
 209         blk_unregister_queue(disk);
 210         blk_unregister_region(MKDEV(disk->major, disk->first_minor),
 211                               disk->minors);
 212 }
 213
 214 /**
 215  * get_gendisk - get partitioning information for a given device
 216  * @dev: device to get partitioning information for
 217  *
 218  * This function gets the structure containing partitioning
 219  * information for the given device @dev.
 220  */
 221 struct gendisk *get_gendisk(dev_t devt, int *part)
 222 {
 223         struct kobject *kobj = kobj_lookup(bdev_map, devt, part);
 224         struct device *dev = kobj_to_dev(kobj);
 225
 226         return  kobj ? dev_to_disk(dev) : NULL;
 227 }
 228
 229 /*
 230  * print a partitions - intended for places where the root filesystem can't be
 231  * mounted and thus to give the victim some idea of what went wrong
 232  */
 233 static int printk_partition(struct device *dev, void *data)
 234 {
 235         struct gendisk *sgp;
 236         char buf[BDEVNAME_SIZE];
 237         int n;
 238
 239         if (dev->type != &disk_type)
 240                 goto exit;
 241
 242         sgp = dev_to_disk(dev);
 243         /*
 244          * Don't show empty devices or things that have been surpressed
 245          */
 246         if (get_capacity(sgp) == 0 ||
 247             (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 248                 goto exit;
 249
 250         /*
 251          * Note, unlike /proc/partitions, I am showing the numbers in
 252          * hex - the same format as the root= option takes.
 253          */
 254         printk("%02x%02x %10llu %s",
 255                 sgp->major, sgp->first_minor,
 256                 (unsigned long long)get_capacity(sgp) >> 1,
 257                 disk_name(sgp, 0, buf));
 258         if (sgp->driverfs_dev != NULL &&
 259             sgp->driverfs_dev->driver != NULL)
 260                 printk(" driver: %s\n",
 261                         sgp->driverfs_dev->driver->name);
 262         else
 263                 printk(" (driver?)\n");
 264
 265         /* now show the partitions */
 266         for (n = 0; n < sgp->minors - 1; ++n) {
 267                 if (sgp->part[n] == NULL)
 268                         goto exit;
 269                 if (sgp->part[n]->nr_sects == 0)
 270                         goto exit;
 271                 printk("  %02x%02x %10llu %s\n",
 272                         sgp->major, n + 1 + sgp->first_minor,
 273                         (unsigned long long)sgp->part[n]->nr_sects >> 1,
 274                         disk_name(sgp, n + 1, buf));
 275         }
 276 exit:
 277         return 0;
 278 }
 279
 280 /*
 281  * print a full list of all partitions - intended for places where the root
 282  * filesystem can't be mounted and thus to give the victim some idea of what
 283  * went wrong
 284  */
 285 void __init printk_all_partitions(void)
 286 {
 287         mutex_lock(&block_class_lock);
 288         class_for_each_device(&block_class, NULL, NULL, printk_partition);
 289         mutex_unlock(&block_class_lock);
 290 }
 291
 292 #ifdef CONFIG_PROC_FS
 293 /* iterator */
 294 static void *part_start(struct seq_file *part, loff_t *pos)
 295 {
 296         loff_t k = *pos;
 297         struct device *dev;
 298
 299         mutex_lock(&block_class_lock);
 300         list_for_each_entry(dev, &block_class.devices, node) {
 301                 if (dev->type != &disk_type)
 302                         continue;
 303                 if (!k--)
 304                         return dev_to_disk(dev);
 305         }
 306         return NULL;
 307 }
 308
 309 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 310 {
 311         struct gendisk *gp = v;
 312         struct device *dev;
 313         ++*pos;
 314         list_for_each_entry(dev, &gp->dev.node, node) {
 315                 if (&dev->node == &block_class.devices)
 316                         return NULL;
 317                 if (dev->type == &disk_type)
 318                         return dev_to_disk(dev);
 319         }
 320         return NULL;
 321 }
 322
 323 static void part_stop(struct seq_file *part, void *v)
 324 {
 325         mutex_unlock(&block_class_lock);
 326 }
 327
 328 static int show_partition(struct seq_file *part, void *v)
 329 {
 330         struct gendisk *sgp = v;
 331         int n;
 332         char buf[BDEVNAME_SIZE];
 333
 334         if (&sgp->dev.node == block_class.devices.next)
 335                 seq_puts(part, "major minor  #blocks  name\n\n");
 336
 337         /* Don't show non-partitionable removeable devices or empty devices */
 338         if (!get_capacity(sgp) ||
 339                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 340                 return 0;
 341         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 342                 return 0;
 343
 344         /* show the full disk and all non-0 size partitions of it */
 345         seq_printf(part, "%4d  %4d %10llu %s\n",
 346                 sgp->major, sgp->first_minor,
 347                 (unsigned long long)get_capacity(sgp) >> 1,
 348                 disk_name(sgp, 0, buf));
 349         for (n = 0; n < sgp->minors - 1; n++) {
 350                 if (!sgp->part[n])
 351                         continue;
 352                 if (sgp->part[n]->nr_sects == 0)
 353                         continue;
 354                 seq_printf(part, "%4d  %4d %10llu %s\n",
 355                         sgp->major, n + 1 + sgp->first_minor,
 356                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 357                         disk_name(sgp, n + 1, buf));
 358         }
 359
 360         return 0;
 361 }
 362
 363 const struct seq_operations partitions_op = {
 364         .start  = part_start,
 365         .next   = part_next,
 366         .stop   = part_stop,
 367         .show   = show_partition
 368 };
 369 #endif
 370
 371
 372 static struct kobject *base_probe(dev_t devt, int *part, void *data)
 373 {
 374         if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
 375                 /* Make old-style 2.4 aliases work */
 376                 request_module("block-major-%d", MAJOR(devt));
 377         return NULL;
 378 }
 379
 380 static int __init genhd_device_init(void)
 381 {
 382         int error;
 383
 384         block_class.dev_kobj = sysfs_dev_block_kobj;
 385         error = class_register(&block_class);
 386         if (unlikely(error))
 387                 return error;
 388         bdev_map = kobj_map_init(base_probe, &block_class_lock);
 389         blk_dev_init();
 390
 391 #ifndef CONFIG_SYSFS_DEPRECATED
 392         /* create top-level block dir */
 393         block_depr = kobject_create_and_add("block", NULL);
 394 #endif
 395         return 0;
 396 }
 397
 398 subsys_initcall(genhd_device_init);
 399
 400 static ssize_t disk_range_show(struct device *dev,
 401                                struct device_attribute *attr, char *buf)
 402 {
 403         struct gendisk *disk = dev_to_disk(dev);
 404
 405         return sprintf(buf, "%d\n", disk->minors);
 406 }
 407
 408 static ssize_t disk_removable_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",
 414                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 415 }
 416
 417 static ssize_t disk_ro_show(struct device *dev,
 418                                    struct device_attribute *attr, char *buf)
 419 {
 420         struct gendisk *disk = dev_to_disk(dev);
 421
 422         return sprintf(buf, "%d\n", disk->policy ? 1 : 0);
 423 }
 424
 425 static ssize_t disk_size_show(struct device *dev,
 426                               struct device_attribute *attr, char *buf)
 427 {
 428         struct gendisk *disk = dev_to_disk(dev);
 429
 430         return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
 431 }
 432
 433 static ssize_t disk_capability_show(struct device *dev,
 434                                     struct device_attribute *attr, char *buf)
 435 {
 436         struct gendisk *disk = dev_to_disk(dev);
 437
 438         return sprintf(buf, "%x\n", disk->flags);
 439 }
 440
 441 static ssize_t disk_stat_show(struct device *dev,
 442                               struct device_attribute *attr, char *buf)
 443 {
 444         struct gendisk *disk = dev_to_disk(dev);
 445
 446         preempt_disable();
 447         disk_round_stats(disk);
 448         preempt_enable();
 449         return sprintf(buf,
 450                 "%8lu %8lu %8llu %8u "
 451                 "%8lu %8lu %8llu %8u "
 452                 "%8u %8u %8u"
 453                 "\n",
 454                 disk_stat_read(disk, ios[READ]),
 455                 disk_stat_read(disk, merges[READ]),
 456                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 457                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 458                 disk_stat_read(disk, ios[WRITE]),
 459                 disk_stat_read(disk, merges[WRITE]),
 460                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 461                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 462                 disk->in_flight,
 463                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 464                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 465 }
 466
 467 #ifdef CONFIG_FAIL_MAKE_REQUEST
 468 static ssize_t disk_fail_show(struct device *dev,
 469                               struct device_attribute *attr, char *buf)
 470 {
 471         struct gendisk *disk = dev_to_disk(dev);
 472
 473         return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 474 }
 475
 476 static ssize_t disk_fail_store(struct device *dev,
 477                                struct device_attribute *attr,
 478                                const char *buf, size_t count)
 479 {
 480         struct gendisk *disk = dev_to_disk(dev);
 481         int i;
 482
 483         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 484                 if (i == 0)
 485                         disk->flags &= ~GENHD_FL_FAIL;
 486                 else
 487                         disk->flags |= GENHD_FL_FAIL;
 488         }
 489
 490         return count;
 491 }
 492
 493 #endif
 494
 495 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 496 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
 497 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
 498 static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
 499 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
 500 static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
 501 #ifdef CONFIG_FAIL_MAKE_REQUEST
 502 static struct device_attribute dev_attr_fail =
 503         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
 504 #endif
 505
 506 static struct attribute *disk_attrs[] = {
 507         &dev_attr_range.attr,
 508         &dev_attr_removable.attr,
 509         &dev_attr_ro.attr,
 510         &dev_attr_size.attr,
 511         &dev_attr_capability.attr,
 512         &dev_attr_stat.attr,
 513 #ifdef CONFIG_FAIL_MAKE_REQUEST
 514         &dev_attr_fail.attr,
 515 #endif
 516         NULL
 517 };
 518
 519 static struct attribute_group disk_attr_group = {
 520         .attrs = disk_attrs,
 521 };
 522
 523 static struct attribute_group *disk_attr_groups[] = {
 524         &disk_attr_group,
 525         NULL
 526 };
 527
 528 static void disk_release(struct device *dev)
 529 {
 530         struct gendisk *disk = dev_to_disk(dev);
 531
 532         kfree(disk->random);
 533         kfree(disk->part);
 534         free_disk_stats(disk);
 535         kfree(disk);
 536 }
 537 struct class block_class = {
 538         .name           = "block",
 539 };
 540
 541 static struct device_type disk_type = {
 542         .name           = "disk",
 543         .groups         = disk_attr_groups,
 544         .release        = disk_release,
 545 };
 546
 547 #ifdef CONFIG_PROC_FS
 548 /*
 549  * aggregate disk stat collector.  Uses the same stats that the sysfs
 550  * entries do, above, but makes them available through one seq_file.
 551  *
 552  * The output looks suspiciously like /proc/partitions with a bunch of
 553  * extra fields.
 554  */
 555
 556 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 557 {
 558         loff_t k = *pos;
 559         struct device *dev;
 560
 561         mutex_lock(&block_class_lock);
 562         list_for_each_entry(dev, &block_class.devices, node) {
 563                 if (dev->type != &disk_type)
 564                         continue;
 565                 if (!k--)
 566                         return dev_to_disk(dev);
 567         }
 568         return NULL;
 569 }
 570
 571 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 572 {
 573         struct gendisk *gp = v;
 574         struct device *dev;
 575
 576         ++*pos;
 577         list_for_each_entry(dev, &gp->dev.node, node) {
 578                 if (&dev->node == &block_class.devices)
 579                         return NULL;
 580                 if (dev->type == &disk_type)
 581                         return dev_to_disk(dev);
 582         }
 583         return NULL;
 584 }
 585
 586 static void diskstats_stop(struct seq_file *part, void *v)
 587 {
 588         mutex_unlock(&block_class_lock);
 589 }
 590
 591 static int diskstats_show(struct seq_file *s, void *v)
 592 {
 593         struct gendisk *gp = v;
 594         char buf[BDEVNAME_SIZE];
 595         int n = 0;
 596
 597         /*
 598         if (&gp->dev.kobj.entry == block_class.devices.next)
 599                 seq_puts(s,     "major minor name"
 600                                 "     rio rmerge rsect ruse wio wmerge "
 601                                 "wsect wuse running use aveq"
 602                                 "\n\n");
 603         */
 604
 605         preempt_disable();
 606         disk_round_stats(gp);
 607         preempt_enable();
 608         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 609                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 610                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 611                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 612                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 613                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 614                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 615                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 616                 gp->in_flight,
 617                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 618                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 619
 620         /* now show all non-0 size partitions of it */
 621         for (n = 0; n < gp->minors - 1; n++) {
 622                 struct hd_struct *hd = gp->part[n];
 623
 624                 if (!hd || !hd->nr_sects)
 625                         continue;
 626
 627                 preempt_disable();
 628                 part_round_stats(hd);
 629                 preempt_enable();
 630                 seq_printf(s, "%4d %4d %s %lu %lu %llu "
 631                            "%u %lu %lu %llu %u %u %u %u\n",
 632                            gp->major, n + gp->first_minor + 1,
 633                            disk_name(gp, n + 1, buf),
 634                            part_stat_read(hd, ios[0]),
 635                            part_stat_read(hd, merges[0]),
 636                            (unsigned long long)part_stat_read(hd, sectors[0]),
 637                            jiffies_to_msecs(part_stat_read(hd, ticks[0])),
 638                            part_stat_read(hd, ios[1]),
 639                            part_stat_read(hd, merges[1]),
 640                            (unsigned long long)part_stat_read(hd, sectors[1]),
 641                            jiffies_to_msecs(part_stat_read(hd, ticks[1])),
 642                            hd->in_flight,
 643                            jiffies_to_msecs(part_stat_read(hd, io_ticks)),
 644                            jiffies_to_msecs(part_stat_read(hd, time_in_queue))
 645                         );
 646         }
 647
 648         return 0;
 649 }
 650
 651 const struct seq_operations diskstats_op = {
 652         .start  = diskstats_start,
 653         .next   = diskstats_next,
 654         .stop   = diskstats_stop,
 655         .show   = diskstats_show
 656 };
 657 #endif /* CONFIG_PROC_FS */
 658
 659 static void media_change_notify_thread(struct work_struct *work)
 660 {
 661         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 662         char event[] = "MEDIA_CHANGE=1";
 663         char *envp[] = { event, NULL };
 664
 665         /*
 666          * set enviroment vars to indicate which event this is for
 667          * so that user space will know to go check the media status.
 668          */
 669         kobject_uevent_env(&gd->dev.kobj, KOBJ_CHANGE, envp);
 670         put_device(gd->driverfs_dev);
 671 }
 672
 673 #if 0
 674 void genhd_media_change_notify(struct gendisk *disk)
 675 {
 676         get_device(disk->driverfs_dev);
 677         schedule_work(&disk->async_notify);
 678 }
 679 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 680 #endif  /*  0  */
 681
 682 struct find_block {
 683         const char *name;
 684         int part;
 685 };
 686
 687 static int match_id(struct device *dev, void *data)
 688 {
 689         struct find_block *find = data;
 690
 691         if (dev->type != &disk_type)
 692                 return 0;
 693         if (strcmp(dev->bus_id, find->name) == 0) {
 694                 struct gendisk *disk = dev_to_disk(dev);
 695                 if (find->part < disk->minors)
 696                         return 1;
 697         }
 698         return 0;
 699 }
 700
 701 dev_t blk_lookup_devt(const char *name, int part)
 702 {
 703         struct device *dev;
 704         dev_t devt = MKDEV(0, 0);
 705         struct find_block find;
 706
 707         mutex_lock(&block_class_lock);
 708         find.name = name;
 709         find.part = part;
 710         dev = class_find_device(&block_class, NULL, (void *)&find, match_id);
 711         if (dev)
 712                 devt = MKDEV(MAJOR(dev->devt),
 713                              MINOR(dev->devt) + part);
 714         mutex_unlock(&block_class_lock);
 715
 716         return devt;
 717 }
 718 EXPORT_SYMBOL(blk_lookup_devt);
 719
 720 struct gendisk *alloc_disk(int minors)
 721 {
 722         return alloc_disk_node(minors, -1);
 723 }
 724
 725 struct gendisk *alloc_disk_node(int minors, int node_id)
 726 {
 727         struct gendisk *disk;
 728
 729         disk = kmalloc_node(sizeof(struct gendisk),
 730                                 GFP_KERNEL | __GFP_ZERO, node_id);
 731         if (disk) {
 732                 if (!init_disk_stats(disk)) {
 733                         kfree(disk);
 734                         return NULL;
 735                 }
 736                 if (minors > 1) {
 737                         int size = (minors - 1) * sizeof(struct hd_struct *);
 738                         disk->part = kmalloc_node(size,
 739                                 GFP_KERNEL | __GFP_ZERO, node_id);
 740                         if (!disk->part) {
 741                                 free_disk_stats(disk);
 742                                 kfree(disk);
 743                                 return NULL;
 744                         }
 745                 }
 746                 disk->minors = minors;
 747                 rand_initialize_disk(disk);
 748                 disk->dev.class = &block_class;
 749                 disk->dev.type = &disk_type;
 750                 device_initialize(&disk->dev);
 751                 INIT_WORK(&disk->async_notify,
 752                         media_change_notify_thread);
 753         }
 754         return disk;
 755 }
 756
 757 EXPORT_SYMBOL(alloc_disk);
 758 EXPORT_SYMBOL(alloc_disk_node);
 759
 760 struct kobject *get_disk(struct gendisk *disk)
 761 {
 762         struct module *owner;
 763         struct kobject *kobj;
 764
 765         if (!disk->fops)
 766                 return NULL;
 767         owner = disk->fops->owner;
 768         if (owner && !try_module_get(owner))
 769                 return NULL;
 770         kobj = kobject_get(&disk->dev.kobj);
 771         if (kobj == NULL) {
 772                 module_put(owner);
 773                 return NULL;
 774         }
 775         return kobj;
 776
 777 }
 778
 779 EXPORT_SYMBOL(get_disk);
 780
 781 void put_disk(struct gendisk *disk)
 782 {
 783         if (disk)
 784                 kobject_put(&disk->dev.kobj);
 785 }
 786
 787 EXPORT_SYMBOL(put_disk);
 788
 789 void set_device_ro(struct block_device *bdev, int flag)
 790 {
 791         if (bdev->bd_contains != bdev)
 792                 bdev->bd_part->policy = flag;
 793         else
 794                 bdev->bd_disk->policy = flag;
 795 }
 796
 797 EXPORT_SYMBOL(set_device_ro);
 798
 799 void set_disk_ro(struct gendisk *disk, int flag)
 800 {
 801         int i;
 802         disk->policy = flag;
 803         for (i = 0; i < disk->minors - 1; i++)
 804                 if (disk->part[i]) disk->part[i]->policy = flag;
 805 }
 806
 807 EXPORT_SYMBOL(set_disk_ro);
 808
 809 int bdev_read_only(struct block_device *bdev)
 810 {
 811         if (!bdev)
 812                 return 0;
 813         else if (bdev->bd_contains != bdev)
 814                 return bdev->bd_part->policy;
 815         else
 816                 return bdev->bd_disk->policy;
 817 }
 818
 819 EXPORT_SYMBOL(bdev_read_only);
 820
 821 int invalidate_partition(struct gendisk *disk, int index)
 822 {
 823         int res = 0;
 824         struct block_device *bdev = bdget_disk(disk, index);
 825         if (bdev) {
 826                 fsync_bdev(bdev);
 827                 res = __invalidate_device(bdev);
 828                 bdput(bdev);
 829         }
 830         return res;
 831 }
 832
 833 EXPORT_SYMBOL(invalidate_partition);