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_subsys;
  21 static DEFINE_MUTEX(block_subsys_lock);
  22
  23 /*
  24  * Can be deleted altogether. Later.
  25  *
  26  */
  27 static struct blk_major_name {
  28         struct blk_major_name *next;
  29         int major;
  30         char name[16];
  31 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
  32
  33 /* index in the above - for now: assume no multimajor ranges */
  34 static inline int major_to_index(int major)
  35 {
  36         return major % BLKDEV_MAJOR_HASH_SIZE;
  37 }
  38
  39 #ifdef CONFIG_PROC_FS
  40
  41 void blkdev_show(struct seq_file *f, off_t offset)
  42 {
  43         struct blk_major_name *dp;
  44
  45         if (offset < BLKDEV_MAJOR_HASH_SIZE) {
  46                 mutex_lock(&block_subsys_lock);
  47                 for (dp = major_names[offset]; dp; dp = dp->next)
  48                         seq_printf(f, "%3d %s\n", dp->major, dp->name);
  49                 mutex_unlock(&block_subsys_lock);
  50         }
  51 }
  52
  53 #endif /* CONFIG_PROC_FS */
  54
  55 int register_blkdev(unsigned int major, const char *name)
  56 {
  57         struct blk_major_name **n, *p;
  58         int index, ret = 0;
  59
  60         mutex_lock(&block_subsys_lock);
  61
  62         /* temporary */
  63         if (major == 0) {
  64                 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
  65                         if (major_names[index] == NULL)
  66                                 break;
  67                 }
  68
  69                 if (index == 0) {
  70                         printk("register_blkdev: failed to get major for %s\n",
  71                                name);
  72                         ret = -EBUSY;
  73                         goto out;
  74                 }
  75                 major = index;
  76                 ret = major;
  77         }
  78
  79         p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
  80         if (p == NULL) {
  81                 ret = -ENOMEM;
  82                 goto out;
  83         }
  84
  85         p->major = major;
  86         strlcpy(p->name, name, sizeof(p->name));
  87         p->next = NULL;
  88         index = major_to_index(major);
  89
  90         for (n = &major_names[index]; *n; n = &(*n)->next) {
  91                 if ((*n)->major == major)
  92                         break;
  93         }
  94         if (!*n)
  95                 *n = p;
  96         else
  97                 ret = -EBUSY;
  98
  99         if (ret < 0) {
 100                 printk("register_blkdev: cannot get major %d for %s\n",
 101                        major, name);
 102                 kfree(p);
 103         }
 104 out:
 105         mutex_unlock(&block_subsys_lock);
 106         return ret;
 107 }
 108
 109 EXPORT_SYMBOL(register_blkdev);
 110
 111 void unregister_blkdev(unsigned int major, const char *name)
 112 {
 113         struct blk_major_name **n;
 114         struct blk_major_name *p = NULL;
 115         int index = major_to_index(major);
 116
 117         mutex_lock(&block_subsys_lock);
 118         for (n = &major_names[index]; *n; n = &(*n)->next)
 119                 if ((*n)->major == major)
 120                         break;
 121         if (!*n || strcmp((*n)->name, name)) {
 122                 WARN_ON(1);
 123         } else {
 124                 p = *n;
 125                 *n = p->next;
 126         }
 127         mutex_unlock(&block_subsys_lock);
 128         kfree(p);
 129 }
 130
 131 EXPORT_SYMBOL(unregister_blkdev);
 132
 133 static struct kobj_map *bdev_map;
 134
 135 /*
 136  * Register device numbers dev..(dev+range-1)
 137  * range must be nonzero
 138  * The hash chain is sorted on range, so that subranges can override.
 139  */
 140 void blk_register_region(dev_t dev, unsigned long range, struct module *module,
 141                          struct kobject *(*probe)(dev_t, int *, void *),
 142                          int (*lock)(dev_t, void *), void *data)
 143 {
 144         kobj_map(bdev_map, dev, range, module, probe, lock, data);
 145 }
 146
 147 EXPORT_SYMBOL(blk_register_region);
 148
 149 void blk_unregister_region(dev_t dev, unsigned long range)
 150 {
 151         kobj_unmap(bdev_map, dev, range);
 152 }
 153
 154 EXPORT_SYMBOL(blk_unregister_region);
 155
 156 static struct kobject *exact_match(dev_t dev, int *part, void *data)
 157 {
 158         struct gendisk *p = data;
 159         return &p->kobj;
 160 }
 161
 162 static int exact_lock(dev_t dev, void *data)
 163 {
 164         struct gendisk *p = data;
 165
 166         if (!get_disk(p))
 167                 return -1;
 168         return 0;
 169 }
 170
 171 /**
 172  * add_disk - add partitioning information to kernel list
 173  * @disk: per-device partitioning information
 174  *
 175  * This function registers the partitioning information in @disk
 176  * with the kernel.
 177  */
 178 void add_disk(struct gendisk *disk)
 179 {
 180         disk->flags |= GENHD_FL_UP;
 181         blk_register_region(MKDEV(disk->major, disk->first_minor),
 182                             disk->minors, NULL, exact_match, exact_lock, disk);
 183         register_disk(disk);
 184         blk_register_queue(disk);
 185 }
 186
 187 EXPORT_SYMBOL(add_disk);
 188 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 189
 190 void unlink_gendisk(struct gendisk *disk)
 191 {
 192         blk_unregister_queue(disk);
 193         blk_unregister_region(MKDEV(disk->major, disk->first_minor),
 194                               disk->minors);
 195 }
 196
 197 #define to_disk(obj) container_of(obj,struct gendisk,kobj)
 198
 199 /**
 200  * get_gendisk - get partitioning information for a given device
 201  * @dev: device to get partitioning information for
 202  *
 203  * This function gets the structure containing partitioning
 204  * information for the given device @dev.
 205  */
 206 struct gendisk *get_gendisk(dev_t dev, int *part)
 207 {
 208         struct kobject *kobj = kobj_lookup(bdev_map, dev, part);
 209         return  kobj ? to_disk(kobj) : NULL;
 210 }
 211
 212 /*
 213  * print a full list of all partitions - intended for places where the root
 214  * filesystem can't be mounted and thus to give the victim some idea of what
 215  * went wrong
 216  */
 217 void __init printk_all_partitions(void)
 218 {
 219         int n;
 220         struct gendisk *sgp;
 221
 222         mutex_lock(&block_subsys_lock);
 223         /* For each block device... */
 224         list_for_each_entry(sgp, &block_subsys.list, kobj.entry) {
 225                 char buf[BDEVNAME_SIZE];
 226                 /*
 227                  * Don't show empty devices or things that have been surpressed
 228                  */
 229                 if (get_capacity(sgp) == 0 ||
 230                     (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 231                         continue;
 232
 233                 /*
 234                  * Note, unlike /proc/partitions, I am showing the numbers in
 235                  * hex - the same format as the root= option takes.
 236                  */
 237                 printk("%02x%02x %10llu %s",
 238                         sgp->major, sgp->first_minor,
 239                         (unsigned long long)get_capacity(sgp) >> 1,
 240                         disk_name(sgp, 0, buf));
 241                 if (sgp->driverfs_dev != NULL &&
 242                     sgp->driverfs_dev->driver != NULL)
 243                         printk(" driver: %s\n",
 244                                 sgp->driverfs_dev->driver->name);
 245                 else
 246                         printk(" (driver?)\n");
 247
 248                 /* now show the partitions */
 249                 for (n = 0; n < sgp->minors - 1; ++n) {
 250                         if (sgp->part[n] == NULL)
 251                                 continue;
 252                         if (sgp->part[n]->nr_sects == 0)
 253                                 continue;
 254                         printk("  %02x%02x %10llu %s\n",
 255                                 sgp->major, n + 1 + sgp->first_minor,
 256                                 (unsigned long long)sgp->part[n]->nr_sects >> 1,
 257                                 disk_name(sgp, n + 1, buf));
 258                 } /* partition subloop */
 259         } /* Block device loop */
 260
 261         mutex_unlock(&block_subsys_lock);
 262         return;
 263 }
 264
 265 #ifdef CONFIG_PROC_FS
 266 /* iterator */
 267 static void *part_start(struct seq_file *part, loff_t *pos)
 268 {
 269         struct list_head *p;
 270         loff_t l = *pos;
 271
 272         mutex_lock(&block_subsys_lock);
 273         list_for_each(p, &block_subsys.list)
 274                 if (!l--)
 275                         return list_entry(p, struct gendisk, kobj.entry);
 276         return NULL;
 277 }
 278
 279 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 280 {
 281         struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
 282         ++*pos;
 283         return p==&block_subsys.list ? NULL :
 284                 list_entry(p, struct gendisk, kobj.entry);
 285 }
 286
 287 static void part_stop(struct seq_file *part, void *v)
 288 {
 289         mutex_unlock(&block_subsys_lock);
 290 }
 291
 292 static int show_partition(struct seq_file *part, void *v)
 293 {
 294         struct gendisk *sgp = v;
 295         int n;
 296         char buf[BDEVNAME_SIZE];
 297
 298         if (&sgp->kobj.entry == block_subsys.list.next)
 299                 seq_puts(part, "major minor  #blocks  name\n\n");
 300
 301         /* Don't show non-partitionable removeable devices or empty devices */
 302         if (!get_capacity(sgp) ||
 303                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 304                 return 0;
 305         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 306                 return 0;
 307
 308         /* show the full disk and all non-0 size partitions of it */
 309         seq_printf(part, "%4d  %4d %10llu %s\n",
 310                 sgp->major, sgp->first_minor,
 311                 (unsigned long long)get_capacity(sgp) >> 1,
 312                 disk_name(sgp, 0, buf));
 313         for (n = 0; n < sgp->minors - 1; n++) {
 314                 if (!sgp->part[n])
 315                         continue;
 316                 if (sgp->part[n]->nr_sects == 0)
 317                         continue;
 318                 seq_printf(part, "%4d  %4d %10llu %s\n",
 319                         sgp->major, n + 1 + sgp->first_minor,
 320                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 321                         disk_name(sgp, n + 1, buf));
 322         }
 323
 324         return 0;
 325 }
 326
 327 struct seq_operations partitions_op = {
 328         .start =part_start,
 329         .next = part_next,
 330         .stop = part_stop,
 331         .show = show_partition
 332 };
 333 #endif
 334
 335
 336 extern int blk_dev_init(void);
 337
 338 static struct kobject *base_probe(dev_t dev, int *part, void *data)
 339 {
 340         if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
 341                 /* Make old-style 2.4 aliases work */
 342                 request_module("block-major-%d", MAJOR(dev));
 343         return NULL;
 344 }
 345
 346 static int __init genhd_device_init(void)
 347 {
 348         int err;
 349
 350         bdev_map = kobj_map_init(base_probe, &block_subsys_lock);
 351         blk_dev_init();
 352         err = subsystem_register(&block_subsys);
 353         if (err < 0)
 354                 printk(KERN_WARNING "%s: subsystem_register error: %d\n",
 355                         __FUNCTION__, err);
 356         return err;
 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, char **envp,
 544                          int num_envp, char *buffer, int buffer_size)
 545 {
 546         struct kobj_type *ktype = get_ktype(kobj);
 547         struct device *physdev;
 548         struct gendisk *disk;
 549         struct hd_struct *part;
 550         int length = 0;
 551         int i = 0;
 552
 553         if (ktype == &ktype_block) {
 554                 disk = container_of(kobj, struct gendisk, kobj);
 555                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 556                                &length, "MINOR=%u", disk->first_minor);
 557         } else if (ktype == &ktype_part) {
 558                 disk = container_of(kobj->parent, struct gendisk, kobj);
 559                 part = container_of(kobj, struct hd_struct, kobj);
 560                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 561                                &length, "MINOR=%u",
 562                                disk->first_minor + part->partno);
 563         } else
 564                 return 0;
 565
 566         add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
 567                        "MAJOR=%u", disk->major);
 568
 569         /* add physical device, backing this device  */
 570         physdev = disk->driverfs_dev;
 571         if (physdev) {
 572                 char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL);
 573
 574                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 575                                &length, "PHYSDEVPATH=%s", path);
 576                 kfree(path);
 577
 578                 if (physdev->bus)
 579                         add_uevent_var(envp, num_envp, &i,
 580                                        buffer, buffer_size, &length,
 581                                        "PHYSDEVBUS=%s",
 582                                        physdev->bus->name);
 583
 584                 if (physdev->driver)
 585                         add_uevent_var(envp, num_envp, &i,
 586                                        buffer, buffer_size, &length,
 587                                        "PHYSDEVDRIVER=%s",
 588                                        physdev->driver->name);
 589         }
 590
 591         /* terminate, set to next free slot, shrink available space */
 592         envp[i] = NULL;
 593         envp = &envp[i];
 594         num_envp -= i;
 595         buffer = &buffer[length];
 596         buffer_size -= length;
 597
 598         return 0;
 599 }
 600
 601 static struct kset_uevent_ops block_uevent_ops = {
 602         .filter         = block_uevent_filter,
 603         .uevent         = block_uevent,
 604 };
 605
 606 decl_subsys(block, &ktype_block, &block_uevent_ops);
 607
 608 /*
 609  * aggregate disk stat collector.  Uses the same stats that the sysfs
 610  * entries do, above, but makes them available through one seq_file.
 611  * Watching a few disks may be efficient through sysfs, but watching
 612  * all of them will be more efficient through this interface.
 613  *
 614  * The output looks suspiciously like /proc/partitions with a bunch of
 615  * extra fields.
 616  */
 617
 618 /* iterator */
 619 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 620 {
 621         loff_t k = *pos;
 622         struct list_head *p;
 623
 624         mutex_lock(&block_subsys_lock);
 625         list_for_each(p, &block_subsys.list)
 626                 if (!k--)
 627                         return list_entry(p, struct gendisk, kobj.entry);
 628         return NULL;
 629 }
 630
 631 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 632 {
 633         struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
 634         ++*pos;
 635         return p==&block_subsys.list ? NULL :
 636                 list_entry(p, struct gendisk, kobj.entry);
 637 }
 638
 639 static void diskstats_stop(struct seq_file *part, void *v)
 640 {
 641         mutex_unlock(&block_subsys_lock);
 642 }
 643
 644 static int diskstats_show(struct seq_file *s, void *v)
 645 {
 646         struct gendisk *gp = v;
 647         char buf[BDEVNAME_SIZE];
 648         int n = 0;
 649
 650         /*
 651         if (&sgp->kobj.entry == block_subsys.kset.list.next)
 652                 seq_puts(s,     "major minor name"
 653                                 "     rio rmerge rsect ruse wio wmerge "
 654                                 "wsect wuse running use aveq"
 655                                 "\n\n");
 656         */
 657
 658         preempt_disable();
 659         disk_round_stats(gp);
 660         preempt_enable();
 661         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 662                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 663                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 664                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 665                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 666                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 667                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 668                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 669                 gp->in_flight,
 670                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 671                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 672
 673         /* now show all non-0 size partitions of it */
 674         for (n = 0; n < gp->minors - 1; n++) {
 675                 struct hd_struct *hd = gp->part[n];
 676
 677                 if (hd && hd->nr_sects)
 678                         seq_printf(s, "%4d %4d %s %u %u %u %u\n",
 679                                 gp->major, n + gp->first_minor + 1,
 680                                 disk_name(gp, n + 1, buf),
 681                                 hd->ios[0], hd->sectors[0],
 682                                 hd->ios[1], hd->sectors[1]);
 683         }
 684
 685         return 0;
 686 }
 687
 688 struct seq_operations diskstats_op = {
 689         .start  = diskstats_start,
 690         .next   = diskstats_next,
 691         .stop   = diskstats_stop,
 692         .show   = diskstats_show
 693 };
 694
 695 static void media_change_notify_thread(struct work_struct *work)
 696 {
 697         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 698         char event[] = "MEDIA_CHANGE=1";
 699         char *envp[] = { event, NULL };
 700
 701         /*
 702          * set enviroment vars to indicate which event this is for
 703          * so that user space will know to go check the media status.
 704          */
 705         kobject_uevent_env(&gd->kobj, KOBJ_CHANGE, envp);
 706         put_device(gd->driverfs_dev);
 707 }
 708
 709 void genhd_media_change_notify(struct gendisk *disk)
 710 {
 711         get_device(disk->driverfs_dev);
 712         schedule_work(&disk->async_notify);
 713 }
 714 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 715
 716 struct gendisk *alloc_disk(int minors)
 717 {
 718         return alloc_disk_node(minors, -1);
 719 }
 720
 721 struct gendisk *alloc_disk_node(int minors, int node_id)
 722 {
 723         struct gendisk *disk;
 724
 725         disk = kmalloc_node(sizeof(struct gendisk),
 726                                 GFP_KERNEL | __GFP_ZERO, node_id);
 727         if (disk) {
 728                 if (!init_disk_stats(disk)) {
 729                         kfree(disk);
 730                         return NULL;
 731                 }
 732                 if (minors > 1) {
 733                         int size = (minors - 1) * sizeof(struct hd_struct *);
 734                         disk->part = kmalloc_node(size,
 735                                 GFP_KERNEL | __GFP_ZERO, node_id);
 736                         if (!disk->part) {
 737                                 kfree(disk);
 738                                 return NULL;
 739                         }
 740                 }
 741                 disk->minors = minors;
 742                 kobj_set_kset_s(disk,block_subsys);
 743                 kobject_init(&disk->kobj);
 744                 rand_initialize_disk(disk);
 745                 INIT_WORK(&disk->async_notify,
 746                         media_change_notify_thread);
 747         }
 748         return disk;
 749 }
 750
 751 EXPORT_SYMBOL(alloc_disk);
 752 EXPORT_SYMBOL(alloc_disk_node);
 753
 754 struct kobject *get_disk(struct gendisk *disk)
 755 {
 756         struct module *owner;
 757         struct kobject *kobj;
 758
 759         if (!disk->fops)
 760                 return NULL;
 761         owner = disk->fops->owner;
 762         if (owner && !try_module_get(owner))
 763                 return NULL;
 764         kobj = kobject_get(&disk->kobj);
 765         if (kobj == NULL) {
 766                 module_put(owner);
 767                 return NULL;
 768         }
 769         return kobj;
 770
 771 }
 772
 773 EXPORT_SYMBOL(get_disk);
 774
 775 void put_disk(struct gendisk *disk)
 776 {
 777         if (disk)
 778                 kobject_put(&disk->kobj);
 779 }
 780
 781 EXPORT_SYMBOL(put_disk);
 782
 783 void set_device_ro(struct block_device *bdev, int flag)
 784 {
 785         if (bdev->bd_contains != bdev)
 786                 bdev->bd_part->policy = flag;
 787         else
 788                 bdev->bd_disk->policy = flag;
 789 }
 790
 791 EXPORT_SYMBOL(set_device_ro);
 792
 793 void set_disk_ro(struct gendisk *disk, int flag)
 794 {
 795         int i;
 796         disk->policy = flag;
 797         for (i = 0; i < disk->minors - 1; i++)
 798                 if (disk->part[i]) disk->part[i]->policy = flag;
 799 }
 800
 801 EXPORT_SYMBOL(set_disk_ro);
 802
 803 int bdev_read_only(struct block_device *bdev)
 804 {
 805         if (!bdev)
 806                 return 0;
 807         else if (bdev->bd_contains != bdev)
 808                 return bdev->bd_part->policy;
 809         else
 810                 return bdev->bd_disk->policy;
 811 }
 812
 813 EXPORT_SYMBOL(bdev_read_only);
 814
 815 int invalidate_partition(struct gendisk *disk, int index)
 816 {
 817         int res = 0;
 818         struct block_device *bdev = bdget_disk(disk, index);
 819         if (bdev) {
 820                 fsync_bdev(bdev);
 821                 res = __invalidate_device(bdev);
 822                 bdput(bdev);
 823         }
 824         return res;
 825 }
 826
 827 EXPORT_SYMBOL(invalidate_partition);