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
 194         bdi = &disk->queue->backing_dev_info;
 195         bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor));
 196         retval = sysfs_create_link(&disk->dev.kobj, &bdi->dev->kobj, "bdi");
 197         WARN_ON(retval);
 198 }
 199
 200 EXPORT_SYMBOL(add_disk);
 201 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 202
 203 void unlink_gendisk(struct gendisk *disk)
 204 {
 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  * @devt: device to get partitioning information for
 215  * @part: returned partition index
 216  *
 217  * This function gets the structure containing partitioning
 218  * information for the given device @devt.
 219  */
 220 struct gendisk *get_gendisk(dev_t devt, int *part)
 221 {
 222         struct kobject *kobj = kobj_lookup(bdev_map, devt, part);
 223         struct device *dev = kobj_to_dev(kobj);
 224
 225         return  kobj ? dev_to_disk(dev) : NULL;
 226 }
 227
 228 /*
 229  * print a full list of all partitions - intended for places where the root
 230  * filesystem can't be mounted and thus to give the victim some idea of what
 231  * went wrong
 232  */
 233 void __init printk_all_partitions(void)
 234 {
 235         struct class_dev_iter iter;
 236         struct device *dev;
 237
 238         class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
 239         while ((dev = class_dev_iter_next(&iter))) {
 240                 struct gendisk *disk = dev_to_disk(dev);
 241                 char buf[BDEVNAME_SIZE];
 242                 int n;
 243
 244                 /*
 245                  * Don't show empty devices or things that have been
 246                  * surpressed
 247                  */
 248                 if (get_capacity(disk) == 0 ||
 249                     (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 250                         continue;
 251
 252                 /*
 253                  * Note, unlike /proc/partitions, I am showing the
 254                  * numbers in hex - the same format as the root=
 255                  * option takes.
 256                  */
 257                 printk("%02x%02x %10llu %s",
 258                        disk->major, disk->first_minor,
 259                        (unsigned long long)get_capacity(disk) >> 1,
 260                        disk_name(disk, 0, buf));
 261                 if (disk->driverfs_dev != NULL &&
 262                     disk->driverfs_dev->driver != NULL)
 263                         printk(" driver: %s\n",
 264                                disk->driverfs_dev->driver->name);
 265                 else
 266                         printk(" (driver?)\n");
 267
 268                 /* now show the partitions */
 269                 for (n = 0; n < disk->minors - 1; ++n) {
 270                         if (disk->part[n] == NULL)
 271                                 continue;
 272                         if (disk->part[n]->nr_sects == 0)
 273                                 continue;
 274                         printk("  %02x%02x %10llu %s\n",
 275                                disk->major, n + 1 + disk->first_minor,
 276                                (unsigned long long)disk->part[n]->nr_sects >> 1,
 277                                disk_name(disk, n + 1, buf));
 278                 }
 279         }
 280         class_dev_iter_exit(&iter);
 281 }
 282
 283 #ifdef CONFIG_PROC_FS
 284 /* iterator */
 285 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
 286 {
 287         loff_t skip = *pos;
 288         struct class_dev_iter *iter;
 289         struct device *dev;
 290
 291         iter = kmalloc(GFP_KERNEL, sizeof(*iter));
 292         if (!iter)
 293                 return ERR_PTR(-ENOMEM);
 294
 295         seqf->private = iter;
 296         class_dev_iter_init(iter, &block_class, NULL, &disk_type);
 297         do {
 298                 dev = class_dev_iter_next(iter);
 299                 if (!dev)
 300                         return NULL;
 301         } while (skip--);
 302
 303         return dev_to_disk(dev);
 304 }
 305
 306 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
 307 {
 308         struct device *dev;
 309
 310         (*pos)++;
 311         dev = class_dev_iter_next(seqf->private);
 312         if (dev)
 313                 return dev_to_disk(dev);
 314
 315         return NULL;
 316 }
 317
 318 static void disk_seqf_stop(struct seq_file *seqf, void *v)
 319 {
 320         struct class_dev_iter *iter = seqf->private;
 321
 322         /* stop is called even after start failed :-( */
 323         if (iter) {
 324                 class_dev_iter_exit(iter);
 325                 kfree(iter);
 326         }
 327 }
 328
 329 static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
 330 {
 331         static void *p;
 332
 333         p = disk_seqf_start(seqf, pos);
 334         if (!IS_ERR(p) && p)
 335                 seq_puts(seqf, "major minor  #blocks  name\n\n");
 336         return p;
 337 }
 338
 339 static int show_partition(struct seq_file *part, void *v)
 340 {
 341         struct gendisk *sgp = v;
 342         int n;
 343         char buf[BDEVNAME_SIZE];
 344
 345         /*
 346          * Print header if start told us to do.  This is to preserve
 347          * the original behavior of not printing header if no
 348          * partition exists.  This hackery will be removed later with
 349          * class iteration clean up.
 350          */
 351         if (part->private) {
 352                 seq_puts(part, "major minor  #blocks  name\n\n");
 353                 part->private = NULL;
 354         }
 355
 356         /* Don't show non-partitionable removeable devices or empty devices */
 357         if (!get_capacity(sgp) ||
 358                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 359                 return 0;
 360         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 361                 return 0;
 362
 363         /* show the full disk and all non-0 size partitions of it */
 364         seq_printf(part, "%4d  %4d %10llu %s\n",
 365                 sgp->major, sgp->first_minor,
 366                 (unsigned long long)get_capacity(sgp) >> 1,
 367                 disk_name(sgp, 0, buf));
 368         for (n = 0; n < sgp->minors - 1; n++) {
 369                 if (!sgp->part[n])
 370                         continue;
 371                 if (sgp->part[n]->nr_sects == 0)
 372                         continue;
 373                 seq_printf(part, "%4d  %4d %10llu %s\n",
 374                         sgp->major, n + 1 + sgp->first_minor,
 375                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 376                         disk_name(sgp, n + 1, buf));
 377         }
 378
 379         return 0;
 380 }
 381
 382 const struct seq_operations partitions_op = {
 383         .start  = show_partition_start,
 384         .next   = disk_seqf_next,
 385         .stop   = disk_seqf_stop,
 386         .show   = show_partition
 387 };
 388 #endif
 389
 390
 391 static struct kobject *base_probe(dev_t devt, int *part, void *data)
 392 {
 393         if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
 394                 /* Make old-style 2.4 aliases work */
 395                 request_module("block-major-%d", MAJOR(devt));
 396         return NULL;
 397 }
 398
 399 static int __init genhd_device_init(void)
 400 {
 401         int error;
 402
 403         block_class.dev_kobj = sysfs_dev_block_kobj;
 404         error = class_register(&block_class);
 405         if (unlikely(error))
 406                 return error;
 407         bdev_map = kobj_map_init(base_probe, &block_class_lock);
 408         blk_dev_init();
 409
 410 #ifndef CONFIG_SYSFS_DEPRECATED
 411         /* create top-level block dir */
 412         block_depr = kobject_create_and_add("block", NULL);
 413 #endif
 414         return 0;
 415 }
 416
 417 subsys_initcall(genhd_device_init);
 418
 419 static ssize_t disk_range_show(struct device *dev,
 420                                struct device_attribute *attr, char *buf)
 421 {
 422         struct gendisk *disk = dev_to_disk(dev);
 423
 424         return sprintf(buf, "%d\n", disk->minors);
 425 }
 426
 427 static ssize_t disk_removable_show(struct device *dev,
 428                                    struct device_attribute *attr, char *buf)
 429 {
 430         struct gendisk *disk = dev_to_disk(dev);
 431
 432         return sprintf(buf, "%d\n",
 433                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 434 }
 435
 436 static ssize_t disk_ro_show(struct device *dev,
 437                                    struct device_attribute *attr, char *buf)
 438 {
 439         struct gendisk *disk = dev_to_disk(dev);
 440
 441         return sprintf(buf, "%d\n", disk->policy ? 1 : 0);
 442 }
 443
 444 static ssize_t disk_size_show(struct device *dev,
 445                               struct device_attribute *attr, char *buf)
 446 {
 447         struct gendisk *disk = dev_to_disk(dev);
 448
 449         return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
 450 }
 451
 452 static ssize_t disk_capability_show(struct device *dev,
 453                                     struct device_attribute *attr, char *buf)
 454 {
 455         struct gendisk *disk = dev_to_disk(dev);
 456
 457         return sprintf(buf, "%x\n", disk->flags);
 458 }
 459
 460 static ssize_t disk_stat_show(struct device *dev,
 461                               struct device_attribute *attr, char *buf)
 462 {
 463         struct gendisk *disk = dev_to_disk(dev);
 464
 465         preempt_disable();
 466         disk_round_stats(disk);
 467         preempt_enable();
 468         return sprintf(buf,
 469                 "%8lu %8lu %8llu %8u "
 470                 "%8lu %8lu %8llu %8u "
 471                 "%8u %8u %8u"
 472                 "\n",
 473                 disk_stat_read(disk, ios[READ]),
 474                 disk_stat_read(disk, merges[READ]),
 475                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 476                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 477                 disk_stat_read(disk, ios[WRITE]),
 478                 disk_stat_read(disk, merges[WRITE]),
 479                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 480                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 481                 disk->in_flight,
 482                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 483                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 484 }
 485
 486 #ifdef CONFIG_FAIL_MAKE_REQUEST
 487 static ssize_t disk_fail_show(struct device *dev,
 488                               struct device_attribute *attr, char *buf)
 489 {
 490         struct gendisk *disk = dev_to_disk(dev);
 491
 492         return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 493 }
 494
 495 static ssize_t disk_fail_store(struct device *dev,
 496                                struct device_attribute *attr,
 497                                const char *buf, size_t count)
 498 {
 499         struct gendisk *disk = dev_to_disk(dev);
 500         int i;
 501
 502         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 503                 if (i == 0)
 504                         disk->flags &= ~GENHD_FL_FAIL;
 505                 else
 506                         disk->flags |= GENHD_FL_FAIL;
 507         }
 508
 509         return count;
 510 }
 511
 512 #endif
 513
 514 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 515 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
 516 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
 517 static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
 518 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
 519 static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
 520 #ifdef CONFIG_FAIL_MAKE_REQUEST
 521 static struct device_attribute dev_attr_fail =
 522         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
 523 #endif
 524
 525 static struct attribute *disk_attrs[] = {
 526         &dev_attr_range.attr,
 527         &dev_attr_removable.attr,
 528         &dev_attr_ro.attr,
 529         &dev_attr_size.attr,
 530         &dev_attr_capability.attr,
 531         &dev_attr_stat.attr,
 532 #ifdef CONFIG_FAIL_MAKE_REQUEST
 533         &dev_attr_fail.attr,
 534 #endif
 535         NULL
 536 };
 537
 538 static struct attribute_group disk_attr_group = {
 539         .attrs = disk_attrs,
 540 };
 541
 542 static struct attribute_group *disk_attr_groups[] = {
 543         &disk_attr_group,
 544         NULL
 545 };
 546
 547 static void disk_release(struct device *dev)
 548 {
 549         struct gendisk *disk = dev_to_disk(dev);
 550
 551         kfree(disk->random);
 552         kfree(disk->part);
 553         free_disk_stats(disk);
 554         kfree(disk);
 555 }
 556 struct class block_class = {
 557         .name           = "block",
 558 };
 559
 560 static struct device_type disk_type = {
 561         .name           = "disk",
 562         .groups         = disk_attr_groups,
 563         .release        = disk_release,
 564 };
 565
 566 #ifdef CONFIG_PROC_FS
 567 static int diskstats_show(struct seq_file *s, void *v)
 568 {
 569         struct gendisk *gp = v;
 570         char buf[BDEVNAME_SIZE];
 571         int n;
 572
 573         /*
 574         if (&gp->dev.kobj.entry == block_class.devices.next)
 575                 seq_puts(s,     "major minor name"
 576                                 "     rio rmerge rsect ruse wio wmerge "
 577                                 "wsect wuse running use aveq"
 578                                 "\n\n");
 579         */
 580
 581         preempt_disable();
 582         disk_round_stats(gp);
 583         preempt_enable();
 584         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 585                 gp->major, gp->first_minor, disk_name(gp, 0, buf),
 586                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 587                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 588                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 589                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 590                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 591                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 592                 gp->in_flight,
 593                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 594                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 595
 596         /* now show all non-0 size partitions of it */
 597         for (n = 0; n < gp->minors - 1; n++) {
 598                 struct hd_struct *hd = gp->part[n];
 599
 600                 if (!hd || !hd->nr_sects)
 601                         continue;
 602
 603                 preempt_disable();
 604                 part_round_stats(hd);
 605                 preempt_enable();
 606                 seq_printf(s, "%4d %4d %s %lu %lu %llu "
 607                            "%u %lu %lu %llu %u %u %u %u\n",
 608                            gp->major, n + gp->first_minor + 1,
 609                            disk_name(gp, n + 1, buf),
 610                            part_stat_read(hd, ios[0]),
 611                            part_stat_read(hd, merges[0]),
 612                            (unsigned long long)part_stat_read(hd, sectors[0]),
 613                            jiffies_to_msecs(part_stat_read(hd, ticks[0])),
 614                            part_stat_read(hd, ios[1]),
 615                            part_stat_read(hd, merges[1]),
 616                            (unsigned long long)part_stat_read(hd, sectors[1]),
 617                            jiffies_to_msecs(part_stat_read(hd, ticks[1])),
 618                            hd->in_flight,
 619                            jiffies_to_msecs(part_stat_read(hd, io_ticks)),
 620                            jiffies_to_msecs(part_stat_read(hd, time_in_queue))
 621                         );
 622         }
 623
 624         return 0;
 625 }
 626
 627 const struct seq_operations diskstats_op = {
 628         .start  = disk_seqf_start,
 629         .next   = disk_seqf_next,
 630         .stop   = disk_seqf_stop,
 631         .show   = diskstats_show
 632 };
 633 #endif /* CONFIG_PROC_FS */
 634
 635 static void media_change_notify_thread(struct work_struct *work)
 636 {
 637         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 638         char event[] = "MEDIA_CHANGE=1";
 639         char *envp[] = { event, NULL };
 640
 641         /*
 642          * set enviroment vars to indicate which event this is for
 643          * so that user space will know to go check the media status.
 644          */
 645         kobject_uevent_env(&gd->dev.kobj, KOBJ_CHANGE, envp);
 646         put_device(gd->driverfs_dev);
 647 }
 648
 649 #if 0
 650 void genhd_media_change_notify(struct gendisk *disk)
 651 {
 652         get_device(disk->driverfs_dev);
 653         schedule_work(&disk->async_notify);
 654 }
 655 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 656 #endif  /*  0  */
 657
 658 dev_t blk_lookup_devt(const char *name, int part)
 659 {
 660         dev_t devt = MKDEV(0, 0);
 661         struct class_dev_iter iter;
 662         struct device *dev;
 663
 664         class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
 665         while ((dev = class_dev_iter_next(&iter))) {
 666                 struct gendisk *disk = dev_to_disk(dev);
 667
 668                 if (!strcmp(dev->bus_id, name) && part < disk->minors) {
 669                         devt = MKDEV(MAJOR(dev->devt),
 670                                      MINOR(dev->devt) + part);
 671                         break;
 672                 }
 673         }
 674         class_dev_iter_exit(&iter);
 675         return devt;
 676 }
 677 EXPORT_SYMBOL(blk_lookup_devt);
 678
 679 struct gendisk *alloc_disk(int minors)
 680 {
 681         return alloc_disk_node(minors, -1);
 682 }
 683
 684 struct gendisk *alloc_disk_node(int minors, int node_id)
 685 {
 686         struct gendisk *disk;
 687
 688         disk = kmalloc_node(sizeof(struct gendisk),
 689                                 GFP_KERNEL | __GFP_ZERO, node_id);
 690         if (disk) {
 691                 if (!init_disk_stats(disk)) {
 692                         kfree(disk);
 693                         return NULL;
 694                 }
 695                 if (minors > 1) {
 696                         int size = (minors - 1) * sizeof(struct hd_struct *);
 697                         disk->part = kmalloc_node(size,
 698                                 GFP_KERNEL | __GFP_ZERO, node_id);
 699                         if (!disk->part) {
 700                                 free_disk_stats(disk);
 701                                 kfree(disk);
 702                                 return NULL;
 703                         }
 704                 }
 705                 disk->minors = minors;
 706                 rand_initialize_disk(disk);
 707                 disk->dev.class = &block_class;
 708                 disk->dev.type = &disk_type;
 709                 device_initialize(&disk->dev);
 710                 INIT_WORK(&disk->async_notify,
 711                         media_change_notify_thread);
 712         }
 713         return disk;
 714 }
 715
 716 EXPORT_SYMBOL(alloc_disk);
 717 EXPORT_SYMBOL(alloc_disk_node);
 718
 719 struct kobject *get_disk(struct gendisk *disk)
 720 {
 721         struct module *owner;
 722         struct kobject *kobj;
 723
 724         if (!disk->fops)
 725                 return NULL;
 726         owner = disk->fops->owner;
 727         if (owner && !try_module_get(owner))
 728                 return NULL;
 729         kobj = kobject_get(&disk->dev.kobj);
 730         if (kobj == NULL) {
 731                 module_put(owner);
 732                 return NULL;
 733         }
 734         return kobj;
 735
 736 }
 737
 738 EXPORT_SYMBOL(get_disk);
 739
 740 void put_disk(struct gendisk *disk)
 741 {
 742         if (disk)
 743                 kobject_put(&disk->dev.kobj);
 744 }
 745
 746 EXPORT_SYMBOL(put_disk);
 747
 748 void set_device_ro(struct block_device *bdev, int flag)
 749 {
 750         if (bdev->bd_contains != bdev)
 751                 bdev->bd_part->policy = flag;
 752         else
 753                 bdev->bd_disk->policy = flag;
 754 }
 755
 756 EXPORT_SYMBOL(set_device_ro);
 757
 758 void set_disk_ro(struct gendisk *disk, int flag)
 759 {
 760         int i;
 761         disk->policy = flag;
 762         for (i = 0; i < disk->minors - 1; i++)
 763                 if (disk->part[i]) disk->part[i]->policy = flag;
 764 }
 765
 766 EXPORT_SYMBOL(set_disk_ro);
 767
 768 int bdev_read_only(struct block_device *bdev)
 769 {
 770         if (!bdev)
 771                 return 0;
 772         else if (bdev->bd_contains != bdev)
 773                 return bdev->bd_part->policy;
 774         else
 775                 return bdev->bd_disk->policy;
 776 }
 777
 778 EXPORT_SYMBOL(bdev_read_only);
 779
 780 int invalidate_partition(struct gendisk *disk, int index)
 781 {
 782         int res = 0;
 783         struct block_device *bdev = bdget_disk(disk, index);
 784         if (bdev) {
 785                 fsync_bdev(bdev);
 786                 res = __invalidate_device(bdev);
 787                 bdput(bdev);
 788         }
 789         return res;
 790 }
 791
 792 EXPORT_SYMBOL(invalidate_partition);