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 /* todo: make void - error printk here */
 112 int 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         int ret = 0;
 118
 119         mutex_lock(&block_subsys_lock);
 120         for (n = &major_names[index]; *n; n = &(*n)->next)
 121                 if ((*n)->major == major)
 122                         break;
 123         if (!*n || strcmp((*n)->name, name))
 124                 ret = -EINVAL;
 125         else {
 126                 p = *n;
 127                 *n = p->next;
 128         }
 129         mutex_unlock(&block_subsys_lock);
 130         kfree(p);
 131
 132         return ret;
 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 dev, 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, dev, range, module, probe, lock, data);
 149 }
 150
 151 EXPORT_SYMBOL(blk_register_region);
 152
 153 void blk_unregister_region(dev_t dev, unsigned long range)
 154 {
 155         kobj_unmap(bdev_map, dev, range);
 156 }
 157
 158 EXPORT_SYMBOL(blk_unregister_region);
 159
 160 static struct kobject *exact_match(dev_t dev, int *part, void *data)
 161 {
 162         struct gendisk *p = data;
 163         return &p->kobj;
 164 }
 165
 166 static int exact_lock(dev_t dev, void *data)
 167 {
 168         struct gendisk *p = data;
 169
 170         if (!get_disk(p))
 171                 return -1;
 172         return 0;
 173 }
 174
 175 /**
 176  * add_disk - add partitioning information to kernel list
 177  * @disk: per-device partitioning information
 178  *
 179  * This function registers the partitioning information in @disk
 180  * with the kernel.
 181  */
 182 void add_disk(struct gendisk *disk)
 183 {
 184         disk->flags |= GENHD_FL_UP;
 185         blk_register_region(MKDEV(disk->major, disk->first_minor),
 186                             disk->minors, NULL, exact_match, exact_lock, disk);
 187         register_disk(disk);
 188         blk_register_queue(disk);
 189 }
 190
 191 EXPORT_SYMBOL(add_disk);
 192 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 193
 194 void unlink_gendisk(struct gendisk *disk)
 195 {
 196         blk_unregister_queue(disk);
 197         blk_unregister_region(MKDEV(disk->major, disk->first_minor),
 198                               disk->minors);
 199 }
 200
 201 #define to_disk(obj) container_of(obj,struct gendisk,kobj)
 202
 203 /**
 204  * get_gendisk - get partitioning information for a given device
 205  * @dev: device to get partitioning information for
 206  *
 207  * This function gets the structure containing partitioning
 208  * information for the given device @dev.
 209  */
 210 struct gendisk *get_gendisk(dev_t dev, int *part)
 211 {
 212         struct kobject *kobj = kobj_lookup(bdev_map, dev, part);
 213         return  kobj ? to_disk(kobj) : NULL;
 214 }
 215
 216 /*
 217  * print a full list of all partitions - intended for places where the root
 218  * filesystem can't be mounted and thus to give the victim some idea of what
 219  * went wrong
 220  */
 221 void __init printk_all_partitions(void)
 222 {
 223         int n;
 224         struct gendisk *sgp;
 225
 226         mutex_lock(&block_subsys_lock);
 227         /* For each block device... */
 228         list_for_each_entry(sgp, &block_subsys.list, kobj.entry) {
 229                 char buf[BDEVNAME_SIZE];
 230                 /*
 231                  * Don't show empty devices or things that have been surpressed
 232                  */
 233                 if (get_capacity(sgp) == 0 ||
 234                     (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 235                         continue;
 236
 237                 /*
 238                  * Note, unlike /proc/partitions, I am showing the numbers in
 239                  * hex - the same format as the root= option takes.
 240                  */
 241                 printk("%02x%02x %10llu %s",
 242                         sgp->major, sgp->first_minor,
 243                         (unsigned long long)get_capacity(sgp) >> 1,
 244                         disk_name(sgp, 0, buf));
 245                 if (sgp->driverfs_dev != NULL &&
 246                     sgp->driverfs_dev->driver != NULL)
 247                         printk(" driver: %s\n",
 248                                 sgp->driverfs_dev->driver->name);
 249                 else
 250                         printk(" (driver?)\n");
 251
 252                 /* now show the partitions */
 253                 for (n = 0; n < sgp->minors - 1; ++n) {
 254                         if (sgp->part[n] == NULL)
 255                                 continue;
 256                         if (sgp->part[n]->nr_sects == 0)
 257                                 continue;
 258                         printk("  %02x%02x %10llu %s\n",
 259                                 sgp->major, n + 1 + sgp->first_minor,
 260                                 (unsigned long long)sgp->part[n]->nr_sects >> 1,
 261                                 disk_name(sgp, n + 1, buf));
 262                 } /* partition subloop */
 263         } /* Block device loop */
 264
 265         mutex_unlock(&block_subsys_lock);
 266         return;
 267 }
 268
 269 #ifdef CONFIG_PROC_FS
 270 /* iterator */
 271 static void *part_start(struct seq_file *part, loff_t *pos)
 272 {
 273         struct list_head *p;
 274         loff_t l = *pos;
 275
 276         mutex_lock(&block_subsys_lock);
 277         list_for_each(p, &block_subsys.list)
 278                 if (!l--)
 279                         return list_entry(p, struct gendisk, kobj.entry);
 280         return NULL;
 281 }
 282
 283 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 284 {
 285         struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
 286         ++*pos;
 287         return p==&block_subsys.list ? NULL :
 288                 list_entry(p, struct gendisk, kobj.entry);
 289 }
 290
 291 static void part_stop(struct seq_file *part, void *v)
 292 {
 293         mutex_unlock(&block_subsys_lock);
 294 }
 295
 296 static int show_partition(struct seq_file *part, void *v)
 297 {
 298         struct gendisk *sgp = v;
 299         int n;
 300         char buf[BDEVNAME_SIZE];
 301
 302         if (&sgp->kobj.entry == block_subsys.list.next)
 303                 seq_puts(part, "major minor  #blocks  name\n\n");
 304
 305         /* Don't show non-partitionable removeable devices or empty devices */
 306         if (!get_capacity(sgp) ||
 307                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 308                 return 0;
 309         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 310                 return 0;
 311
 312         /* show the full disk and all non-0 size partitions of it */
 313         seq_printf(part, "%4d  %4d %10llu %s\n",
 314                 sgp->major, sgp->first_minor,
 315                 (unsigned long long)get_capacity(sgp) >> 1,
 316                 disk_name(sgp, 0, buf));
 317         for (n = 0; n < sgp->minors - 1; n++) {
 318                 if (!sgp->part[n])
 319                         continue;
 320                 if (sgp->part[n]->nr_sects == 0)
 321                         continue;
 322                 seq_printf(part, "%4d  %4d %10llu %s\n",
 323                         sgp->major, n + 1 + sgp->first_minor,
 324                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 325                         disk_name(sgp, n + 1, buf));
 326         }
 327
 328         return 0;
 329 }
 330
 331 struct seq_operations partitions_op = {
 332         .start =part_start,
 333         .next = part_next,
 334         .stop = part_stop,
 335         .show = show_partition
 336 };
 337 #endif
 338
 339
 340 extern int blk_dev_init(void);
 341
 342 static struct kobject *base_probe(dev_t dev, int *part, void *data)
 343 {
 344         if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
 345                 /* Make old-style 2.4 aliases work */
 346                 request_module("block-major-%d", MAJOR(dev));
 347         return NULL;
 348 }
 349
 350 static int __init genhd_device_init(void)
 351 {
 352         int err;
 353
 354         bdev_map = kobj_map_init(base_probe, &block_subsys_lock);
 355         blk_dev_init();
 356         err = subsystem_register(&block_subsys);
 357         if (err < 0)
 358                 printk(KERN_WARNING "%s: subsystem_register error: %d\n",
 359                         __FUNCTION__, err);
 360         return err;
 361 }
 362
 363 subsys_initcall(genhd_device_init);
 364
 365
 366
 367 /*
 368  * kobject & sysfs bindings for block devices
 369  */
 370 static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr,
 371                               char *page)
 372 {
 373         struct gendisk *disk = to_disk(kobj);
 374         struct disk_attribute *disk_attr =
 375                 container_of(attr,struct disk_attribute,attr);
 376         ssize_t ret = -EIO;
 377
 378         if (disk_attr->show)
 379                 ret = disk_attr->show(disk,page);
 380         return ret;
 381 }
 382
 383 static ssize_t disk_attr_store(struct kobject * kobj, struct attribute * attr,
 384                                const char *page, size_t count)
 385 {
 386         struct gendisk *disk = to_disk(kobj);
 387         struct disk_attribute *disk_attr =
 388                 container_of(attr,struct disk_attribute,attr);
 389         ssize_t ret = 0;
 390
 391         if (disk_attr->store)
 392                 ret = disk_attr->store(disk, page, count);
 393         return ret;
 394 }
 395
 396 static struct sysfs_ops disk_sysfs_ops = {
 397         .show   = &disk_attr_show,
 398         .store  = &disk_attr_store,
 399 };
 400
 401 static ssize_t disk_uevent_store(struct gendisk * disk,
 402                                  const char *buf, size_t count)
 403 {
 404         kobject_uevent(&disk->kobj, KOBJ_ADD);
 405         return count;
 406 }
 407 static ssize_t disk_dev_read(struct gendisk * disk, char *page)
 408 {
 409         dev_t base = MKDEV(disk->major, disk->first_minor);
 410         return print_dev_t(page, base);
 411 }
 412 static ssize_t disk_range_read(struct gendisk * disk, char *page)
 413 {
 414         return sprintf(page, "%d\n", disk->minors);
 415 }
 416 static ssize_t disk_removable_read(struct gendisk * disk, char *page)
 417 {
 418         return sprintf(page, "%d\n",
 419                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 420
 421 }
 422 static ssize_t disk_size_read(struct gendisk * disk, char *page)
 423 {
 424         return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
 425 }
 426 static ssize_t disk_capability_read(struct gendisk *disk, char *page)
 427 {
 428         return sprintf(page, "%x\n", disk->flags);
 429 }
 430 static ssize_t disk_stats_read(struct gendisk * disk, char *page)
 431 {
 432         preempt_disable();
 433         disk_round_stats(disk);
 434         preempt_enable();
 435         return sprintf(page,
 436                 "%8lu %8lu %8llu %8u "
 437                 "%8lu %8lu %8llu %8u "
 438                 "%8u %8u %8u"
 439                 "\n",
 440                 disk_stat_read(disk, ios[READ]),
 441                 disk_stat_read(disk, merges[READ]),
 442                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 443                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 444                 disk_stat_read(disk, ios[WRITE]),
 445                 disk_stat_read(disk, merges[WRITE]),
 446                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 447                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 448                 disk->in_flight,
 449                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 450                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 451 }
 452 static struct disk_attribute disk_attr_uevent = {
 453         .attr = {.name = "uevent", .mode = S_IWUSR },
 454         .store  = disk_uevent_store
 455 };
 456 static struct disk_attribute disk_attr_dev = {
 457         .attr = {.name = "dev", .mode = S_IRUGO },
 458         .show   = disk_dev_read
 459 };
 460 static struct disk_attribute disk_attr_range = {
 461         .attr = {.name = "range", .mode = S_IRUGO },
 462         .show   = disk_range_read
 463 };
 464 static struct disk_attribute disk_attr_removable = {
 465         .attr = {.name = "removable", .mode = S_IRUGO },
 466         .show   = disk_removable_read
 467 };
 468 static struct disk_attribute disk_attr_size = {
 469         .attr = {.name = "size", .mode = S_IRUGO },
 470         .show   = disk_size_read
 471 };
 472 static struct disk_attribute disk_attr_capability = {
 473         .attr = {.name = "capability", .mode = S_IRUGO },
 474         .show   = disk_capability_read
 475 };
 476 static struct disk_attribute disk_attr_stat = {
 477         .attr = {.name = "stat", .mode = S_IRUGO },
 478         .show   = disk_stats_read
 479 };
 480
 481 #ifdef CONFIG_FAIL_MAKE_REQUEST
 482
 483 static ssize_t disk_fail_store(struct gendisk * disk,
 484                                const char *buf, size_t count)
 485 {
 486         int i;
 487
 488         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 489                 if (i == 0)
 490                         disk->flags &= ~GENHD_FL_FAIL;
 491                 else
 492                         disk->flags |= GENHD_FL_FAIL;
 493         }
 494
 495         return count;
 496 }
 497 static ssize_t disk_fail_read(struct gendisk * disk, char *page)
 498 {
 499         return sprintf(page, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 500 }
 501 static struct disk_attribute disk_attr_fail = {
 502         .attr = {.name = "make-it-fail", .mode = S_IRUGO | S_IWUSR },
 503         .store  = disk_fail_store,
 504         .show   = disk_fail_read
 505 };
 506
 507 #endif
 508
 509 static struct attribute * default_attrs[] = {
 510         &disk_attr_uevent.attr,
 511         &disk_attr_dev.attr,
 512         &disk_attr_range.attr,
 513         &disk_attr_removable.attr,
 514         &disk_attr_size.attr,
 515         &disk_attr_stat.attr,
 516         &disk_attr_capability.attr,
 517 #ifdef CONFIG_FAIL_MAKE_REQUEST
 518         &disk_attr_fail.attr,
 519 #endif
 520         NULL,
 521 };
 522
 523 static void disk_release(struct kobject * kobj)
 524 {
 525         struct gendisk *disk = to_disk(kobj);
 526         kfree(disk->random);
 527         kfree(disk->part);
 528         free_disk_stats(disk);
 529         kfree(disk);
 530 }
 531
 532 static struct kobj_type ktype_block = {
 533         .release        = disk_release,
 534         .sysfs_ops      = &disk_sysfs_ops,
 535         .default_attrs  = default_attrs,
 536 };
 537
 538 extern struct kobj_type ktype_part;
 539
 540 static int block_uevent_filter(struct kset *kset, struct kobject *kobj)
 541 {
 542         struct kobj_type *ktype = get_ktype(kobj);
 543
 544         return ((ktype == &ktype_block) || (ktype == &ktype_part));
 545 }
 546
 547 static int block_uevent(struct kset *kset, struct kobject *kobj, char **envp,
 548                          int num_envp, char *buffer, int buffer_size)
 549 {
 550         struct kobj_type *ktype = get_ktype(kobj);
 551         struct device *physdev;
 552         struct gendisk *disk;
 553         struct hd_struct *part;
 554         int length = 0;
 555         int i = 0;
 556
 557         if (ktype == &ktype_block) {
 558                 disk = container_of(kobj, struct gendisk, kobj);
 559                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 560                                &length, "MINOR=%u", disk->first_minor);
 561         } else if (ktype == &ktype_part) {
 562                 disk = container_of(kobj->parent, struct gendisk, kobj);
 563                 part = container_of(kobj, struct hd_struct, kobj);
 564                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 565                                &length, "MINOR=%u",
 566                                disk->first_minor + part->partno);
 567         } else
 568                 return 0;
 569
 570         add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
 571                        "MAJOR=%u", disk->major);
 572
 573         /* add physical device, backing this device  */
 574         physdev = disk->driverfs_dev;
 575         if (physdev) {
 576                 char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL);
 577
 578                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 579                                &length, "PHYSDEVPATH=%s", path);
 580                 kfree(path);
 581
 582                 if (physdev->bus)
 583                         add_uevent_var(envp, num_envp, &i,
 584                                        buffer, buffer_size, &length,
 585                                        "PHYSDEVBUS=%s",
 586                                        physdev->bus->name);
 587
 588                 if (physdev->driver)
 589                         add_uevent_var(envp, num_envp, &i,
 590                                        buffer, buffer_size, &length,
 591                                        "PHYSDEVDRIVER=%s",
 592                                        physdev->driver->name);
 593         }
 594
 595         /* terminate, set to next free slot, shrink available space */
 596         envp[i] = NULL;
 597         envp = &envp[i];
 598         num_envp -= i;
 599         buffer = &buffer[length];
 600         buffer_size -= length;
 601
 602         return 0;
 603 }
 604
 605 static struct kset_uevent_ops block_uevent_ops = {
 606         .filter         = block_uevent_filter,
 607         .uevent         = block_uevent,
 608 };
 609
 610 decl_subsys(block, &ktype_block, &block_uevent_ops);
 611
 612 /*
 613  * aggregate disk stat collector.  Uses the same stats that the sysfs
 614  * entries do, above, but makes them available through one seq_file.
 615  * Watching a few disks may be efficient through sysfs, but watching
 616  * all of them will be more efficient through this interface.
 617  *
 618  * The output looks suspiciously like /proc/partitions with a bunch of
 619  * extra fields.
 620  */
 621
 622 /* iterator */
 623 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 624 {
 625         loff_t k = *pos;
 626         struct list_head *p;
 627
 628         mutex_lock(&block_subsys_lock);
 629         list_for_each(p, &block_subsys.list)
 630                 if (!k--)
 631                         return list_entry(p, struct gendisk, kobj.entry);
 632         return NULL;
 633 }
 634
 635 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 636 {
 637         struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
 638         ++*pos;
 639         return p==&block_subsys.list ? NULL :
 640                 list_entry(p, struct gendisk, kobj.entry);
 641 }
 642
 643 static void diskstats_stop(struct seq_file *part, void *v)
 644 {
 645         mutex_unlock(&block_subsys_lock);
 646 }
 647
 648 static int diskstats_show(struct seq_file *s, void *v)
 649 {
 650         struct gendisk *gp = v;
 651         char buf[BDEVNAME_SIZE];
 652         int n = 0;
 653
 654         /*
 655         if (&sgp->kobj.entry == block_subsys.kset.list.next)
 656                 seq_puts(s,     "major minor name"
 657                                 "     rio rmerge rsect ruse wio wmerge "
 658                                 "wsect wuse running use aveq"
 659                                 "\n\n");
 660         */
 661
 662         preempt_disable();
 663         disk_round_stats(gp);
 664         preempt_enable();
 665         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 666                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 667                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 668                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 669                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 670                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 671                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 672                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 673                 gp->in_flight,
 674                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 675                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 676
 677         /* now show all non-0 size partitions of it */
 678         for (n = 0; n < gp->minors - 1; n++) {
 679                 struct hd_struct *hd = gp->part[n];
 680
 681                 if (hd && hd->nr_sects)
 682                         seq_printf(s, "%4d %4d %s %u %u %u %u\n",
 683                                 gp->major, n + gp->first_minor + 1,
 684                                 disk_name(gp, n + 1, buf),
 685                                 hd->ios[0], hd->sectors[0],
 686                                 hd->ios[1], hd->sectors[1]);
 687         }
 688
 689         return 0;
 690 }
 691
 692 struct seq_operations diskstats_op = {
 693         .start  = diskstats_start,
 694         .next   = diskstats_next,
 695         .stop   = diskstats_stop,
 696         .show   = diskstats_show
 697 };
 698
 699 static void media_change_notify_thread(struct work_struct *work)
 700 {
 701         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 702         char event[] = "MEDIA_CHANGE=1";
 703         char *envp[] = { event, NULL };
 704
 705         /*
 706          * set enviroment vars to indicate which event this is for
 707          * so that user space will know to go check the media status.
 708          */
 709         kobject_uevent_env(&gd->kobj, KOBJ_CHANGE, envp);
 710         put_device(gd->driverfs_dev);
 711 }
 712
 713 void genhd_media_change_notify(struct gendisk *disk)
 714 {
 715         get_device(disk->driverfs_dev);
 716         schedule_work(&disk->async_notify);
 717 }
 718 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 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), GFP_KERNEL, node_id);
 730         if (disk) {
 731                 memset(disk, 0, sizeof(struct gendisk));
 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, GFP_KERNEL, node_id);
 739                         if (!disk->part) {
 740                                 kfree(disk);
 741                                 return NULL;
 742                         }
 743                         memset(disk->part, 0, size);
 744                 }
 745                 disk->minors = minors;
 746                 kobj_set_kset_s(disk,block_subsys);
 747                 kobject_init(&disk->kobj);
 748                 rand_initialize_disk(disk);
 749                 INIT_WORK(&disk->async_notify,
 750                         media_change_notify_thread);
 751         }
 752         return disk;
 753 }
 754
 755 EXPORT_SYMBOL(alloc_disk);
 756 EXPORT_SYMBOL(alloc_disk_node);
 757
 758 struct kobject *get_disk(struct gendisk *disk)
 759 {
 760         struct module *owner;
 761         struct kobject *kobj;
 762
 763         if (!disk->fops)
 764                 return NULL;
 765         owner = disk->fops->owner;
 766         if (owner && !try_module_get(owner))
 767                 return NULL;
 768         kobj = kobject_get(&disk->kobj);
 769         if (kobj == NULL) {
 770                 module_put(owner);
 771                 return NULL;
 772         }
 773         return kobj;
 774
 775 }
 776
 777 EXPORT_SYMBOL(get_disk);
 778
 779 void put_disk(struct gendisk *disk)
 780 {
 781         if (disk)
 782                 kobject_put(&disk->kobj);
 783 }
 784
 785 EXPORT_SYMBOL(put_disk);
 786
 787 void set_device_ro(struct block_device *bdev, int flag)
 788 {
 789         if (bdev->bd_contains != bdev)
 790                 bdev->bd_part->policy = flag;
 791         else
 792                 bdev->bd_disk->policy = flag;
 793 }
 794
 795 EXPORT_SYMBOL(set_device_ro);
 796
 797 void set_disk_ro(struct gendisk *disk, int flag)
 798 {
 799         int i;
 800         disk->policy = flag;
 801         for (i = 0; i < disk->minors - 1; i++)
 802                 if (disk->part[i]) disk->part[i]->policy = flag;
 803 }
 804
 805 EXPORT_SYMBOL(set_disk_ro);
 806
 807 int bdev_read_only(struct block_device *bdev)
 808 {
 809         if (!bdev)
 810                 return 0;
 811         else if (bdev->bd_contains != bdev)
 812                 return bdev->bd_part->policy;
 813         else
 814                 return bdev->bd_disk->policy;
 815 }
 816
 817 EXPORT_SYMBOL(bdev_read_only);
 818
 819 int invalidate_partition(struct gendisk *disk, int index)
 820 {
 821         int res = 0;
 822         struct block_device *bdev = bdget_disk(disk, index);
 823         if (bdev) {
 824                 fsync_bdev(bdev);
 825                 res = __invalidate_device(bdev);
 826                 bdput(bdev);
 827         }
 828         return res;
 829 }
 830
 831 EXPORT_SYMBOL(invalidate_partition);