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 struct kset *block_kset;
  21 static struct kset_uevent_ops block_uevent_ops;
  22 static DEFINE_MUTEX(block_subsys_lock);
  23
  24 /*
  25  * Can be deleted altogether. Later.
  26  *
  27  */
  28 static struct blk_major_name {
  29         struct blk_major_name *next;
  30         int major;
  31         char name[16];
  32 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
  33
  34 /* index in the above - for now: assume no multimajor ranges */
  35 static inline int major_to_index(int major)
  36 {
  37         return major % BLKDEV_MAJOR_HASH_SIZE;
  38 }
  39
  40 #ifdef CONFIG_PROC_FS
  41
  42 void blkdev_show(struct seq_file *f, off_t offset)
  43 {
  44         struct blk_major_name *dp;
  45
  46         if (offset < BLKDEV_MAJOR_HASH_SIZE) {
  47                 mutex_lock(&block_subsys_lock);
  48                 for (dp = major_names[offset]; dp; dp = dp->next)
  49                         seq_printf(f, "%3d %s\n", dp->major, dp->name);
  50                 mutex_unlock(&block_subsys_lock);
  51         }
  52 }
  53
  54 #endif /* CONFIG_PROC_FS */
  55
  56 int register_blkdev(unsigned int major, const char *name)
  57 {
  58         struct blk_major_name **n, *p;
  59         int index, ret = 0;
  60
  61         mutex_lock(&block_subsys_lock);
  62
  63         /* temporary */
  64         if (major == 0) {
  65                 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
  66                         if (major_names[index] == NULL)
  67                                 break;
  68                 }
  69
  70                 if (index == 0) {
  71                         printk("register_blkdev: failed to get major for %s\n",
  72                                name);
  73                         ret = -EBUSY;
  74                         goto out;
  75                 }
  76                 major = index;
  77                 ret = major;
  78         }
  79
  80         p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
  81         if (p == NULL) {
  82                 ret = -ENOMEM;
  83                 goto out;
  84         }
  85
  86         p->major = major;
  87         strlcpy(p->name, name, sizeof(p->name));
  88         p->next = NULL;
  89         index = major_to_index(major);
  90
  91         for (n = &major_names[index]; *n; n = &(*n)->next) {
  92                 if ((*n)->major == major)
  93                         break;
  94         }
  95         if (!*n)
  96                 *n = p;
  97         else
  98                 ret = -EBUSY;
  99
 100         if (ret < 0) {
 101                 printk("register_blkdev: cannot get major %d for %s\n",
 102                        major, name);
 103                 kfree(p);
 104         }
 105 out:
 106         mutex_unlock(&block_subsys_lock);
 107         return ret;
 108 }
 109
 110 EXPORT_SYMBOL(register_blkdev);
 111
 112 void unregister_blkdev(unsigned int major, const char *name)
 113 {
 114         struct blk_major_name **n;
 115         struct blk_major_name *p = NULL;
 116         int index = major_to_index(major);
 117
 118         mutex_lock(&block_subsys_lock);
 119         for (n = &major_names[index]; *n; n = &(*n)->next)
 120                 if ((*n)->major == major)
 121                         break;
 122         if (!*n || strcmp((*n)->name, name)) {
 123                 WARN_ON(1);
 124         } else {
 125                 p = *n;
 126                 *n = p->next;
 127         }
 128         mutex_unlock(&block_subsys_lock);
 129         kfree(p);
 130 }
 131
 132 EXPORT_SYMBOL(unregister_blkdev);
 133
 134 static struct kobj_map *bdev_map;
 135
 136 /*
 137  * Register device numbers dev..(dev+range-1)
 138  * range must be nonzero
 139  * The hash chain is sorted on range, so that subranges can override.
 140  */
 141 void blk_register_region(dev_t dev, unsigned long range, struct module *module,
 142                          struct kobject *(*probe)(dev_t, int *, void *),
 143                          int (*lock)(dev_t, void *), void *data)
 144 {
 145         kobj_map(bdev_map, dev, range, module, probe, lock, data);
 146 }
 147
 148 EXPORT_SYMBOL(blk_register_region);
 149
 150 void blk_unregister_region(dev_t dev, unsigned long range)
 151 {
 152         kobj_unmap(bdev_map, dev, range);
 153 }
 154
 155 EXPORT_SYMBOL(blk_unregister_region);
 156
 157 static struct kobject *exact_match(dev_t dev, int *part, void *data)
 158 {
 159         struct gendisk *p = data;
 160         return &p->kobj;
 161 }
 162
 163 static int exact_lock(dev_t dev, void *data)
 164 {
 165         struct gendisk *p = data;
 166
 167         if (!get_disk(p))
 168                 return -1;
 169         return 0;
 170 }
 171
 172 /**
 173  * add_disk - add partitioning information to kernel list
 174  * @disk: per-device partitioning information
 175  *
 176  * This function registers the partitioning information in @disk
 177  * with the kernel.
 178  */
 179 void add_disk(struct gendisk *disk)
 180 {
 181         disk->flags |= GENHD_FL_UP;
 182         blk_register_region(MKDEV(disk->major, disk->first_minor),
 183                             disk->minors, NULL, exact_match, exact_lock, disk);
 184         register_disk(disk);
 185         blk_register_queue(disk);
 186 }
 187
 188 EXPORT_SYMBOL(add_disk);
 189 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 190
 191 void unlink_gendisk(struct gendisk *disk)
 192 {
 193         blk_unregister_queue(disk);
 194         blk_unregister_region(MKDEV(disk->major, disk->first_minor),
 195                               disk->minors);
 196 }
 197
 198 #define to_disk(obj) container_of(obj,struct gendisk,kobj)
 199
 200 /**
 201  * get_gendisk - get partitioning information for a given device
 202  * @dev: device to get partitioning information for
 203  *
 204  * This function gets the structure containing partitioning
 205  * information for the given device @dev.
 206  */
 207 struct gendisk *get_gendisk(dev_t dev, int *part)
 208 {
 209         struct kobject *kobj = kobj_lookup(bdev_map, dev, part);
 210         return  kobj ? to_disk(kobj) : NULL;
 211 }
 212
 213 /*
 214  * print a full list of all partitions - intended for places where the root
 215  * filesystem can't be mounted and thus to give the victim some idea of what
 216  * went wrong
 217  */
 218 void __init printk_all_partitions(void)
 219 {
 220         int n;
 221         struct gendisk *sgp;
 222
 223         mutex_lock(&block_subsys_lock);
 224         /* For each block device... */
 225         list_for_each_entry(sgp, &block_kset->list, kobj.entry) {
 226                 char buf[BDEVNAME_SIZE];
 227                 /*
 228                  * Don't show empty devices or things that have been surpressed
 229                  */
 230                 if (get_capacity(sgp) == 0 ||
 231                     (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 232                         continue;
 233
 234                 /*
 235                  * Note, unlike /proc/partitions, I am showing the numbers in
 236                  * hex - the same format as the root= option takes.
 237                  */
 238                 printk("%02x%02x %10llu %s",
 239                         sgp->major, sgp->first_minor,
 240                         (unsigned long long)get_capacity(sgp) >> 1,
 241                         disk_name(sgp, 0, buf));
 242                 if (sgp->driverfs_dev != NULL &&
 243                     sgp->driverfs_dev->driver != NULL)
 244                         printk(" driver: %s\n",
 245                                 sgp->driverfs_dev->driver->name);
 246                 else
 247                         printk(" (driver?)\n");
 248
 249                 /* now show the partitions */
 250                 for (n = 0; n < sgp->minors - 1; ++n) {
 251                         if (sgp->part[n] == NULL)
 252                                 continue;
 253                         if (sgp->part[n]->nr_sects == 0)
 254                                 continue;
 255                         printk("  %02x%02x %10llu %s\n",
 256                                 sgp->major, n + 1 + sgp->first_minor,
 257                                 (unsigned long long)sgp->part[n]->nr_sects >> 1,
 258                                 disk_name(sgp, n + 1, buf));
 259                 } /* partition subloop */
 260         } /* Block device loop */
 261
 262         mutex_unlock(&block_subsys_lock);
 263         return;
 264 }
 265
 266 #ifdef CONFIG_PROC_FS
 267 /* iterator */
 268 static void *part_start(struct seq_file *part, loff_t *pos)
 269 {
 270         struct list_head *p;
 271         loff_t l = *pos;
 272
 273         mutex_lock(&block_subsys_lock);
 274         list_for_each(p, &block_kset->list)
 275                 if (!l--)
 276                         return list_entry(p, struct gendisk, kobj.entry);
 277         return NULL;
 278 }
 279
 280 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 281 {
 282         struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
 283         ++*pos;
 284         return p==&block_kset->list ? NULL :
 285                 list_entry(p, struct gendisk, kobj.entry);
 286 }
 287
 288 static void part_stop(struct seq_file *part, void *v)
 289 {
 290         mutex_unlock(&block_subsys_lock);
 291 }
 292
 293 static int show_partition(struct seq_file *part, void *v)
 294 {
 295         struct gendisk *sgp = v;
 296         int n;
 297         char buf[BDEVNAME_SIZE];
 298
 299         if (&sgp->kobj.entry == block_kset->list.next)
 300                 seq_puts(part, "major minor  #blocks  name\n\n");
 301
 302         /* Don't show non-partitionable removeable devices or empty devices */
 303         if (!get_capacity(sgp) ||
 304                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 305                 return 0;
 306         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 307                 return 0;
 308
 309         /* show the full disk and all non-0 size partitions of it */
 310         seq_printf(part, "%4d  %4d %10llu %s\n",
 311                 sgp->major, sgp->first_minor,
 312                 (unsigned long long)get_capacity(sgp) >> 1,
 313                 disk_name(sgp, 0, buf));
 314         for (n = 0; n < sgp->minors - 1; n++) {
 315                 if (!sgp->part[n])
 316                         continue;
 317                 if (sgp->part[n]->nr_sects == 0)
 318                         continue;
 319                 seq_printf(part, "%4d  %4d %10llu %s\n",
 320                         sgp->major, n + 1 + sgp->first_minor,
 321                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 322                         disk_name(sgp, n + 1, buf));
 323         }
 324
 325         return 0;
 326 }
 327
 328 struct seq_operations partitions_op = {
 329         .start =part_start,
 330         .next = part_next,
 331         .stop = part_stop,
 332         .show = show_partition
 333 };
 334 #endif
 335
 336
 337 extern int blk_dev_init(void);
 338
 339 static struct kobject *base_probe(dev_t dev, int *part, void *data)
 340 {
 341         if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
 342                 /* Make old-style 2.4 aliases work */
 343                 request_module("block-major-%d", MAJOR(dev));
 344         return NULL;
 345 }
 346
 347 static int __init genhd_device_init(void)
 348 {
 349         bdev_map = kobj_map_init(base_probe, &block_subsys_lock);
 350         blk_dev_init();
 351         block_kset = kset_create_and_register("block", &block_uevent_ops, NULL, NULL);
 352         if (!block_kset) {
 353                 printk(KERN_WARNING "%s: kset_create error\n", __FUNCTION__);
 354                 return -ENOMEM;
 355         }
 356         return 0;
 357 }
 358
 359 subsys_initcall(genhd_device_init);
 360
 361
 362
 363 /*
 364  * kobject & sysfs bindings for block devices
 365  */
 366 static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr,
 367                               char *page)
 368 {
 369         struct gendisk *disk = to_disk(kobj);
 370         struct disk_attribute *disk_attr =
 371                 container_of(attr,struct disk_attribute,attr);
 372         ssize_t ret = -EIO;
 373
 374         if (disk_attr->show)
 375                 ret = disk_attr->show(disk,page);
 376         return ret;
 377 }
 378
 379 static ssize_t disk_attr_store(struct kobject * kobj, struct attribute * attr,
 380                                const char *page, size_t count)
 381 {
 382         struct gendisk *disk = to_disk(kobj);
 383         struct disk_attribute *disk_attr =
 384                 container_of(attr,struct disk_attribute,attr);
 385         ssize_t ret = 0;
 386
 387         if (disk_attr->store)
 388                 ret = disk_attr->store(disk, page, count);
 389         return ret;
 390 }
 391
 392 static struct sysfs_ops disk_sysfs_ops = {
 393         .show   = &disk_attr_show,
 394         .store  = &disk_attr_store,
 395 };
 396
 397 static ssize_t disk_uevent_store(struct gendisk * disk,
 398                                  const char *buf, size_t count)
 399 {
 400         kobject_uevent(&disk->kobj, KOBJ_ADD);
 401         return count;
 402 }
 403 static ssize_t disk_dev_read(struct gendisk * disk, char *page)
 404 {
 405         dev_t base = MKDEV(disk->major, disk->first_minor);
 406         return print_dev_t(page, base);
 407 }
 408 static ssize_t disk_range_read(struct gendisk * disk, char *page)
 409 {
 410         return sprintf(page, "%d\n", disk->minors);
 411 }
 412 static ssize_t disk_removable_read(struct gendisk * disk, char *page)
 413 {
 414         return sprintf(page, "%d\n",
 415                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 416
 417 }
 418 static ssize_t disk_size_read(struct gendisk * disk, char *page)
 419 {
 420         return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
 421 }
 422 static ssize_t disk_capability_read(struct gendisk *disk, char *page)
 423 {
 424         return sprintf(page, "%x\n", disk->flags);
 425 }
 426 static ssize_t disk_stats_read(struct gendisk * disk, char *page)
 427 {
 428         preempt_disable();
 429         disk_round_stats(disk);
 430         preempt_enable();
 431         return sprintf(page,
 432                 "%8lu %8lu %8llu %8u "
 433                 "%8lu %8lu %8llu %8u "
 434                 "%8u %8u %8u"
 435                 "\n",
 436                 disk_stat_read(disk, ios[READ]),
 437                 disk_stat_read(disk, merges[READ]),
 438                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 439                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 440                 disk_stat_read(disk, ios[WRITE]),
 441                 disk_stat_read(disk, merges[WRITE]),
 442                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 443                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 444                 disk->in_flight,
 445                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 446                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 447 }
 448 static struct disk_attribute disk_attr_uevent = {
 449         .attr = {.name = "uevent", .mode = S_IWUSR },
 450         .store  = disk_uevent_store
 451 };
 452 static struct disk_attribute disk_attr_dev = {
 453         .attr = {.name = "dev", .mode = S_IRUGO },
 454         .show   = disk_dev_read
 455 };
 456 static struct disk_attribute disk_attr_range = {
 457         .attr = {.name = "range", .mode = S_IRUGO },
 458         .show   = disk_range_read
 459 };
 460 static struct disk_attribute disk_attr_removable = {
 461         .attr = {.name = "removable", .mode = S_IRUGO },
 462         .show   = disk_removable_read
 463 };
 464 static struct disk_attribute disk_attr_size = {
 465         .attr = {.name = "size", .mode = S_IRUGO },
 466         .show   = disk_size_read
 467 };
 468 static struct disk_attribute disk_attr_capability = {
 469         .attr = {.name = "capability", .mode = S_IRUGO },
 470         .show   = disk_capability_read
 471 };
 472 static struct disk_attribute disk_attr_stat = {
 473         .attr = {.name = "stat", .mode = S_IRUGO },
 474         .show   = disk_stats_read
 475 };
 476
 477 #ifdef CONFIG_FAIL_MAKE_REQUEST
 478
 479 static ssize_t disk_fail_store(struct gendisk * disk,
 480                                const char *buf, size_t count)
 481 {
 482         int i;
 483
 484         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 485                 if (i == 0)
 486                         disk->flags &= ~GENHD_FL_FAIL;
 487                 else
 488                         disk->flags |= GENHD_FL_FAIL;
 489         }
 490
 491         return count;
 492 }
 493 static ssize_t disk_fail_read(struct gendisk * disk, char *page)
 494 {
 495         return sprintf(page, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 496 }
 497 static struct disk_attribute disk_attr_fail = {
 498         .attr = {.name = "make-it-fail", .mode = S_IRUGO | S_IWUSR },
 499         .store  = disk_fail_store,
 500         .show   = disk_fail_read
 501 };
 502
 503 #endif
 504
 505 static struct attribute * default_attrs[] = {
 506         &disk_attr_uevent.attr,
 507         &disk_attr_dev.attr,
 508         &disk_attr_range.attr,
 509         &disk_attr_removable.attr,
 510         &disk_attr_size.attr,
 511         &disk_attr_stat.attr,
 512         &disk_attr_capability.attr,
 513 #ifdef CONFIG_FAIL_MAKE_REQUEST
 514         &disk_attr_fail.attr,
 515 #endif
 516         NULL,
 517 };
 518
 519 static void disk_release(struct kobject * kobj)
 520 {
 521         struct gendisk *disk = to_disk(kobj);
 522         kfree(disk->random);
 523         kfree(disk->part);
 524         free_disk_stats(disk);
 525         kfree(disk);
 526 }
 527
 528 static struct kobj_type ktype_block = {
 529         .release        = disk_release,
 530         .sysfs_ops      = &disk_sysfs_ops,
 531         .default_attrs  = default_attrs,
 532 };
 533
 534 extern struct kobj_type ktype_part;
 535
 536 static int block_uevent_filter(struct kset *kset, struct kobject *kobj)
 537 {
 538         struct kobj_type *ktype = get_ktype(kobj);
 539
 540         return ((ktype == &ktype_block) || (ktype == &ktype_part));
 541 }
 542
 543 static int block_uevent(struct kset *kset, struct kobject *kobj,
 544                         struct kobj_uevent_env *env)
 545 {
 546         struct kobj_type *ktype = get_ktype(kobj);
 547         struct device *physdev;
 548         struct gendisk *disk;
 549         struct hd_struct *part;
 550
 551         if (ktype == &ktype_block) {
 552                 disk = container_of(kobj, struct gendisk, kobj);
 553                 add_uevent_var(env, "MINOR=%u", disk->first_minor);
 554         } else if (ktype == &ktype_part) {
 555                 disk = container_of(kobj->parent, struct gendisk, kobj);
 556                 part = container_of(kobj, struct hd_struct, kobj);
 557                 add_uevent_var(env, "MINOR=%u",
 558                                disk->first_minor + part->partno);
 559         } else
 560                 return 0;
 561
 562         add_uevent_var(env, "MAJOR=%u", disk->major);
 563
 564         /* add physical device, backing this device  */
 565         physdev = disk->driverfs_dev;
 566         if (physdev) {
 567                 char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL);
 568
 569                 add_uevent_var(env, "PHYSDEVPATH=%s", path);
 570                 kfree(path);
 571
 572                 if (physdev->bus)
 573                         add_uevent_var(env, "PHYSDEVBUS=%s", physdev->bus->name);
 574
 575                 if (physdev->driver)
 576                         add_uevent_var(env, physdev->driver->name);
 577         }
 578
 579         return 0;
 580 }
 581
 582 static struct kset_uevent_ops block_uevent_ops = {
 583         .filter         = block_uevent_filter,
 584         .uevent         = block_uevent,
 585 };
 586
 587 /*
 588  * aggregate disk stat collector.  Uses the same stats that the sysfs
 589  * entries do, above, but makes them available through one seq_file.
 590  * Watching a few disks may be efficient through sysfs, but watching
 591  * all of them will be more efficient through this interface.
 592  *
 593  * The output looks suspiciously like /proc/partitions with a bunch of
 594  * extra fields.
 595  */
 596
 597 /* iterator */
 598 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 599 {
 600         loff_t k = *pos;
 601         struct list_head *p;
 602
 603         mutex_lock(&block_subsys_lock);
 604         list_for_each(p, &block_kset->list)
 605                 if (!k--)
 606                         return list_entry(p, struct gendisk, kobj.entry);
 607         return NULL;
 608 }
 609
 610 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 611 {
 612         struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
 613         ++*pos;
 614         return p==&block_kset->list ? NULL :
 615                 list_entry(p, struct gendisk, kobj.entry);
 616 }
 617
 618 static void diskstats_stop(struct seq_file *part, void *v)
 619 {
 620         mutex_unlock(&block_subsys_lock);
 621 }
 622
 623 static int diskstats_show(struct seq_file *s, void *v)
 624 {
 625         struct gendisk *gp = v;
 626         char buf[BDEVNAME_SIZE];
 627         int n = 0;
 628
 629         /*
 630         if (&sgp->kobj.entry == block_kset->list.next)
 631                 seq_puts(s,     "major minor name"
 632                                 "     rio rmerge rsect ruse wio wmerge "
 633                                 "wsect wuse running use aveq"
 634                                 "\n\n");
 635         */
 636
 637         preempt_disable();
 638         disk_round_stats(gp);
 639         preempt_enable();
 640         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 641                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 642                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 643                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 644                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 645                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 646                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 647                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 648                 gp->in_flight,
 649                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 650                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 651
 652         /* now show all non-0 size partitions of it */
 653         for (n = 0; n < gp->minors - 1; n++) {
 654                 struct hd_struct *hd = gp->part[n];
 655
 656                 if (hd && hd->nr_sects)
 657                         seq_printf(s, "%4d %4d %s %u %u %u %u\n",
 658                                 gp->major, n + gp->first_minor + 1,
 659                                 disk_name(gp, n + 1, buf),
 660                                 hd->ios[0], hd->sectors[0],
 661                                 hd->ios[1], hd->sectors[1]);
 662         }
 663
 664         return 0;
 665 }
 666
 667 struct seq_operations diskstats_op = {
 668         .start  = diskstats_start,
 669         .next   = diskstats_next,
 670         .stop   = diskstats_stop,
 671         .show   = diskstats_show
 672 };
 673
 674 static void media_change_notify_thread(struct work_struct *work)
 675 {
 676         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 677         char event[] = "MEDIA_CHANGE=1";
 678         char *envp[] = { event, NULL };
 679
 680         /*
 681          * set enviroment vars to indicate which event this is for
 682          * so that user space will know to go check the media status.
 683          */
 684         kobject_uevent_env(&gd->kobj, KOBJ_CHANGE, envp);
 685         put_device(gd->driverfs_dev);
 686 }
 687
 688 void genhd_media_change_notify(struct gendisk *disk)
 689 {
 690         get_device(disk->driverfs_dev);
 691         schedule_work(&disk->async_notify);
 692 }
 693 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 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                                 kfree(disk);
 717                                 return NULL;
 718                         }
 719                 }
 720                 disk->minors = minors;
 721                 kobject_init(&disk->kobj);
 722                 disk->kobj.kset = block_kset;
 723                 disk->kobj.ktype = &ktype_block;
 724                 rand_initialize_disk(disk);
 725                 INIT_WORK(&disk->async_notify,
 726                         media_change_notify_thread);
 727         }
 728         return disk;
 729 }
 730
 731 EXPORT_SYMBOL(alloc_disk);
 732 EXPORT_SYMBOL(alloc_disk_node);
 733
 734 struct kobject *get_disk(struct gendisk *disk)
 735 {
 736         struct module *owner;
 737         struct kobject *kobj;
 738
 739         if (!disk->fops)
 740                 return NULL;
 741         owner = disk->fops->owner;
 742         if (owner && !try_module_get(owner))
 743                 return NULL;
 744         kobj = kobject_get(&disk->kobj);
 745         if (kobj == NULL) {
 746                 module_put(owner);
 747                 return NULL;
 748         }
 749         return kobj;
 750
 751 }
 752
 753 EXPORT_SYMBOL(get_disk);
 754
 755 void put_disk(struct gendisk *disk)
 756 {
 757         if (disk)
 758                 kobject_put(&disk->kobj);
 759 }
 760
 761 EXPORT_SYMBOL(put_disk);
 762
 763 void set_device_ro(struct block_device *bdev, int flag)
 764 {
 765         if (bdev->bd_contains != bdev)
 766                 bdev->bd_part->policy = flag;
 767         else
 768                 bdev->bd_disk->policy = flag;
 769 }
 770
 771 EXPORT_SYMBOL(set_device_ro);
 772
 773 void set_disk_ro(struct gendisk *disk, int flag)
 774 {
 775         int i;
 776         disk->policy = flag;
 777         for (i = 0; i < disk->minors - 1; i++)
 778                 if (disk->part[i]) disk->part[i]->policy = flag;
 779 }
 780
 781 EXPORT_SYMBOL(set_disk_ro);
 782
 783 int bdev_read_only(struct block_device *bdev)
 784 {
 785         if (!bdev)
 786                 return 0;
 787         else if (bdev->bd_contains != bdev)
 788                 return bdev->bd_part->policy;
 789         else
 790                 return bdev->bd_disk->policy;
 791 }
 792
 793 EXPORT_SYMBOL(bdev_read_only);
 794
 795 int invalidate_partition(struct gendisk *disk, int index)
 796 {
 797         int res = 0;
 798         struct block_device *bdev = bdget_disk(disk, index);
 799         if (bdev) {
 800                 fsync_bdev(bdev);
 801                 res = __invalidate_device(bdev);
 802                 bdput(bdev);
 803         }
 804         return res;
 805 }
 806
 807 EXPORT_SYMBOL(invalidate_partition);