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                 WARN_ON(1);
 125                 ret = -EINVAL;
 126         } else {
 127                 p = *n;
 128                 *n = p->next;
 129         }
 130         mutex_unlock(&block_subsys_lock);
 131         kfree(p);
 132
 133         return ret;
 134 }
 135
 136 EXPORT_SYMBOL(unregister_blkdev);
 137
 138 static struct kobj_map *bdev_map;
 139
 140 /*
 141  * Register device numbers dev..(dev+range-1)
 142  * range must be nonzero
 143  * The hash chain is sorted on range, so that subranges can override.
 144  */
 145 void blk_register_region(dev_t dev, unsigned long range, struct module *module,
 146                          struct kobject *(*probe)(dev_t, int *, void *),
 147                          int (*lock)(dev_t, void *), void *data)
 148 {
 149         kobj_map(bdev_map, dev, range, module, probe, lock, data);
 150 }
 151
 152 EXPORT_SYMBOL(blk_register_region);
 153
 154 void blk_unregister_region(dev_t dev, unsigned long range)
 155 {
 156         kobj_unmap(bdev_map, dev, range);
 157 }
 158
 159 EXPORT_SYMBOL(blk_unregister_region);
 160
 161 static struct kobject *exact_match(dev_t dev, int *part, void *data)
 162 {
 163         struct gendisk *p = data;
 164         return &p->kobj;
 165 }
 166
 167 static int exact_lock(dev_t dev, 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         disk->flags |= GENHD_FL_UP;
 186         blk_register_region(MKDEV(disk->major, disk->first_minor),
 187                             disk->minors, NULL, exact_match, exact_lock, disk);
 188         register_disk(disk);
 189         blk_register_queue(disk);
 190 }
 191
 192 EXPORT_SYMBOL(add_disk);
 193 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 194
 195 void unlink_gendisk(struct gendisk *disk)
 196 {
 197         blk_unregister_queue(disk);
 198         blk_unregister_region(MKDEV(disk->major, disk->first_minor),
 199                               disk->minors);
 200 }
 201
 202 #define to_disk(obj) container_of(obj,struct gendisk,kobj)
 203
 204 /**
 205  * get_gendisk - get partitioning information for a given device
 206  * @dev: device to get partitioning information for
 207  *
 208  * This function gets the structure containing partitioning
 209  * information for the given device @dev.
 210  */
 211 struct gendisk *get_gendisk(dev_t dev, int *part)
 212 {
 213         struct kobject *kobj = kobj_lookup(bdev_map, dev, part);
 214         return  kobj ? to_disk(kobj) : NULL;
 215 }
 216
 217 /*
 218  * print a full list of all partitions - intended for places where the root
 219  * filesystem can't be mounted and thus to give the victim some idea of what
 220  * went wrong
 221  */
 222 void __init printk_all_partitions(void)
 223 {
 224         int n;
 225         struct gendisk *sgp;
 226
 227         mutex_lock(&block_subsys_lock);
 228         /* For each block device... */
 229         list_for_each_entry(sgp, &block_subsys.list, kobj.entry) {
 230                 char buf[BDEVNAME_SIZE];
 231                 /*
 232                  * Don't show empty devices or things that have been surpressed
 233                  */
 234                 if (get_capacity(sgp) == 0 ||
 235                     (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 236                         continue;
 237
 238                 /*
 239                  * Note, unlike /proc/partitions, I am showing the numbers in
 240                  * hex - the same format as the root= option takes.
 241                  */
 242                 printk("%02x%02x %10llu %s",
 243                         sgp->major, sgp->first_minor,
 244                         (unsigned long long)get_capacity(sgp) >> 1,
 245                         disk_name(sgp, 0, buf));
 246                 if (sgp->driverfs_dev != NULL &&
 247                     sgp->driverfs_dev->driver != NULL)
 248                         printk(" driver: %s\n",
 249                                 sgp->driverfs_dev->driver->name);
 250                 else
 251                         printk(" (driver?)\n");
 252
 253                 /* now show the partitions */
 254                 for (n = 0; n < sgp->minors - 1; ++n) {
 255                         if (sgp->part[n] == NULL)
 256                                 continue;
 257                         if (sgp->part[n]->nr_sects == 0)
 258                                 continue;
 259                         printk("  %02x%02x %10llu %s\n",
 260                                 sgp->major, n + 1 + sgp->first_minor,
 261                                 (unsigned long long)sgp->part[n]->nr_sects >> 1,
 262                                 disk_name(sgp, n + 1, buf));
 263                 } /* partition subloop */
 264         } /* Block device loop */
 265
 266         mutex_unlock(&block_subsys_lock);
 267         return;
 268 }
 269
 270 #ifdef CONFIG_PROC_FS
 271 /* iterator */
 272 static void *part_start(struct seq_file *part, loff_t *pos)
 273 {
 274         struct list_head *p;
 275         loff_t l = *pos;
 276
 277         mutex_lock(&block_subsys_lock);
 278         list_for_each(p, &block_subsys.list)
 279                 if (!l--)
 280                         return list_entry(p, struct gendisk, kobj.entry);
 281         return NULL;
 282 }
 283
 284 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 285 {
 286         struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
 287         ++*pos;
 288         return p==&block_subsys.list ? NULL :
 289                 list_entry(p, struct gendisk, kobj.entry);
 290 }
 291
 292 static void part_stop(struct seq_file *part, void *v)
 293 {
 294         mutex_unlock(&block_subsys_lock);
 295 }
 296
 297 static int show_partition(struct seq_file *part, void *v)
 298 {
 299         struct gendisk *sgp = v;
 300         int n;
 301         char buf[BDEVNAME_SIZE];
 302
 303         if (&sgp->kobj.entry == block_subsys.list.next)
 304                 seq_puts(part, "major minor  #blocks  name\n\n");
 305
 306         /* Don't show non-partitionable removeable devices or empty devices */
 307         if (!get_capacity(sgp) ||
 308                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 309                 return 0;
 310         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 311                 return 0;
 312
 313         /* show the full disk and all non-0 size partitions of it */
 314         seq_printf(part, "%4d  %4d %10llu %s\n",
 315                 sgp->major, sgp->first_minor,
 316                 (unsigned long long)get_capacity(sgp) >> 1,
 317                 disk_name(sgp, 0, buf));
 318         for (n = 0; n < sgp->minors - 1; n++) {
 319                 if (!sgp->part[n])
 320                         continue;
 321                 if (sgp->part[n]->nr_sects == 0)
 322                         continue;
 323                 seq_printf(part, "%4d  %4d %10llu %s\n",
 324                         sgp->major, n + 1 + sgp->first_minor,
 325                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 326                         disk_name(sgp, n + 1, buf));
 327         }
 328
 329         return 0;
 330 }
 331
 332 struct seq_operations partitions_op = {
 333         .start =part_start,
 334         .next = part_next,
 335         .stop = part_stop,
 336         .show = show_partition
 337 };
 338 #endif
 339
 340
 341 extern int blk_dev_init(void);
 342
 343 static struct kobject *base_probe(dev_t dev, int *part, void *data)
 344 {
 345         if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
 346                 /* Make old-style 2.4 aliases work */
 347                 request_module("block-major-%d", MAJOR(dev));
 348         return NULL;
 349 }
 350
 351 static int __init genhd_device_init(void)
 352 {
 353         int err;
 354
 355         bdev_map = kobj_map_init(base_probe, &block_subsys_lock);
 356         blk_dev_init();
 357         err = subsystem_register(&block_subsys);
 358         if (err < 0)
 359                 printk(KERN_WARNING "%s: subsystem_register error: %d\n",
 360                         __FUNCTION__, err);
 361         return err;
 362 }
 363
 364 subsys_initcall(genhd_device_init);
 365
 366
 367
 368 /*
 369  * kobject & sysfs bindings for block devices
 370  */
 371 static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr,
 372                               char *page)
 373 {
 374         struct gendisk *disk = to_disk(kobj);
 375         struct disk_attribute *disk_attr =
 376                 container_of(attr,struct disk_attribute,attr);
 377         ssize_t ret = -EIO;
 378
 379         if (disk_attr->show)
 380                 ret = disk_attr->show(disk,page);
 381         return ret;
 382 }
 383
 384 static ssize_t disk_attr_store(struct kobject * kobj, struct attribute * attr,
 385                                const char *page, size_t count)
 386 {
 387         struct gendisk *disk = to_disk(kobj);
 388         struct disk_attribute *disk_attr =
 389                 container_of(attr,struct disk_attribute,attr);
 390         ssize_t ret = 0;
 391
 392         if (disk_attr->store)
 393                 ret = disk_attr->store(disk, page, count);
 394         return ret;
 395 }
 396
 397 static struct sysfs_ops disk_sysfs_ops = {
 398         .show   = &disk_attr_show,
 399         .store  = &disk_attr_store,
 400 };
 401
 402 static ssize_t disk_uevent_store(struct gendisk * disk,
 403                                  const char *buf, size_t count)
 404 {
 405         kobject_uevent(&disk->kobj, KOBJ_ADD);
 406         return count;
 407 }
 408 static ssize_t disk_dev_read(struct gendisk * disk, char *page)
 409 {
 410         dev_t base = MKDEV(disk->major, disk->first_minor);
 411         return print_dev_t(page, base);
 412 }
 413 static ssize_t disk_range_read(struct gendisk * disk, char *page)
 414 {
 415         return sprintf(page, "%d\n", disk->minors);
 416 }
 417 static ssize_t disk_removable_read(struct gendisk * disk, char *page)
 418 {
 419         return sprintf(page, "%d\n",
 420                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 421
 422 }
 423 static ssize_t disk_size_read(struct gendisk * disk, char *page)
 424 {
 425         return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
 426 }
 427 static ssize_t disk_capability_read(struct gendisk *disk, char *page)
 428 {
 429         return sprintf(page, "%x\n", disk->flags);
 430 }
 431 static ssize_t disk_stats_read(struct gendisk * disk, char *page)
 432 {
 433         preempt_disable();
 434         disk_round_stats(disk);
 435         preempt_enable();
 436         return sprintf(page,
 437                 "%8lu %8lu %8llu %8u "
 438                 "%8lu %8lu %8llu %8u "
 439                 "%8u %8u %8u"
 440                 "\n",
 441                 disk_stat_read(disk, ios[READ]),
 442                 disk_stat_read(disk, merges[READ]),
 443                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 444                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 445                 disk_stat_read(disk, ios[WRITE]),
 446                 disk_stat_read(disk, merges[WRITE]),
 447                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 448                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 449                 disk->in_flight,
 450                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 451                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 452 }
 453 static struct disk_attribute disk_attr_uevent = {
 454         .attr = {.name = "uevent", .mode = S_IWUSR },
 455         .store  = disk_uevent_store
 456 };
 457 static struct disk_attribute disk_attr_dev = {
 458         .attr = {.name = "dev", .mode = S_IRUGO },
 459         .show   = disk_dev_read
 460 };
 461 static struct disk_attribute disk_attr_range = {
 462         .attr = {.name = "range", .mode = S_IRUGO },
 463         .show   = disk_range_read
 464 };
 465 static struct disk_attribute disk_attr_removable = {
 466         .attr = {.name = "removable", .mode = S_IRUGO },
 467         .show   = disk_removable_read
 468 };
 469 static struct disk_attribute disk_attr_size = {
 470         .attr = {.name = "size", .mode = S_IRUGO },
 471         .show   = disk_size_read
 472 };
 473 static struct disk_attribute disk_attr_capability = {
 474         .attr = {.name = "capability", .mode = S_IRUGO },
 475         .show   = disk_capability_read
 476 };
 477 static struct disk_attribute disk_attr_stat = {
 478         .attr = {.name = "stat", .mode = S_IRUGO },
 479         .show   = disk_stats_read
 480 };
 481
 482 #ifdef CONFIG_FAIL_MAKE_REQUEST
 483
 484 static ssize_t disk_fail_store(struct gendisk * disk,
 485                                const char *buf, size_t count)
 486 {
 487         int i;
 488
 489         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 490                 if (i == 0)
 491                         disk->flags &= ~GENHD_FL_FAIL;
 492                 else
 493                         disk->flags |= GENHD_FL_FAIL;
 494         }
 495
 496         return count;
 497 }
 498 static ssize_t disk_fail_read(struct gendisk * disk, char *page)
 499 {
 500         return sprintf(page, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 501 }
 502 static struct disk_attribute disk_attr_fail = {
 503         .attr = {.name = "make-it-fail", .mode = S_IRUGO | S_IWUSR },
 504         .store  = disk_fail_store,
 505         .show   = disk_fail_read
 506 };
 507
 508 #endif
 509
 510 static struct attribute * default_attrs[] = {
 511         &disk_attr_uevent.attr,
 512         &disk_attr_dev.attr,
 513         &disk_attr_range.attr,
 514         &disk_attr_removable.attr,
 515         &disk_attr_size.attr,
 516         &disk_attr_stat.attr,
 517         &disk_attr_capability.attr,
 518 #ifdef CONFIG_FAIL_MAKE_REQUEST
 519         &disk_attr_fail.attr,
 520 #endif
 521         NULL,
 522 };
 523
 524 static void disk_release(struct kobject * kobj)
 525 {
 526         struct gendisk *disk = to_disk(kobj);
 527         kfree(disk->random);
 528         kfree(disk->part);
 529         free_disk_stats(disk);
 530         kfree(disk);
 531 }
 532
 533 static struct kobj_type ktype_block = {
 534         .release        = disk_release,
 535         .sysfs_ops      = &disk_sysfs_ops,
 536         .default_attrs  = default_attrs,
 537 };
 538
 539 extern struct kobj_type ktype_part;
 540
 541 static int block_uevent_filter(struct kset *kset, struct kobject *kobj)
 542 {
 543         struct kobj_type *ktype = get_ktype(kobj);
 544
 545         return ((ktype == &ktype_block) || (ktype == &ktype_part));
 546 }
 547
 548 static int block_uevent(struct kset *kset, struct kobject *kobj, char **envp,
 549                          int num_envp, char *buffer, int buffer_size)
 550 {
 551         struct kobj_type *ktype = get_ktype(kobj);
 552         struct device *physdev;
 553         struct gendisk *disk;
 554         struct hd_struct *part;
 555         int length = 0;
 556         int i = 0;
 557
 558         if (ktype == &ktype_block) {
 559                 disk = container_of(kobj, struct gendisk, kobj);
 560                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 561                                &length, "MINOR=%u", disk->first_minor);
 562         } else if (ktype == &ktype_part) {
 563                 disk = container_of(kobj->parent, struct gendisk, kobj);
 564                 part = container_of(kobj, struct hd_struct, kobj);
 565                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 566                                &length, "MINOR=%u",
 567                                disk->first_minor + part->partno);
 568         } else
 569                 return 0;
 570
 571         add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
 572                        "MAJOR=%u", disk->major);
 573
 574         /* add physical device, backing this device  */
 575         physdev = disk->driverfs_dev;
 576         if (physdev) {
 577                 char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL);
 578
 579                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 580                                &length, "PHYSDEVPATH=%s", path);
 581                 kfree(path);
 582
 583                 if (physdev->bus)
 584                         add_uevent_var(envp, num_envp, &i,
 585                                        buffer, buffer_size, &length,
 586                                        "PHYSDEVBUS=%s",
 587                                        physdev->bus->name);
 588
 589                 if (physdev->driver)
 590                         add_uevent_var(envp, num_envp, &i,
 591                                        buffer, buffer_size, &length,
 592                                        "PHYSDEVDRIVER=%s",
 593                                        physdev->driver->name);
 594         }
 595
 596         /* terminate, set to next free slot, shrink available space */
 597         envp[i] = NULL;
 598         envp = &envp[i];
 599         num_envp -= i;
 600         buffer = &buffer[length];
 601         buffer_size -= length;
 602
 603         return 0;
 604 }
 605
 606 static struct kset_uevent_ops block_uevent_ops = {
 607         .filter         = block_uevent_filter,
 608         .uevent         = block_uevent,
 609 };
 610
 611 decl_subsys(block, &ktype_block, &block_uevent_ops);
 612
 613 /*
 614  * aggregate disk stat collector.  Uses the same stats that the sysfs
 615  * entries do, above, but makes them available through one seq_file.
 616  * Watching a few disks may be efficient through sysfs, but watching
 617  * all of them will be more efficient through this interface.
 618  *
 619  * The output looks suspiciously like /proc/partitions with a bunch of
 620  * extra fields.
 621  */
 622
 623 /* iterator */
 624 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 625 {
 626         loff_t k = *pos;
 627         struct list_head *p;
 628
 629         mutex_lock(&block_subsys_lock);
 630         list_for_each(p, &block_subsys.list)
 631                 if (!k--)
 632                         return list_entry(p, struct gendisk, kobj.entry);
 633         return NULL;
 634 }
 635
 636 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 637 {
 638         struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
 639         ++*pos;
 640         return p==&block_subsys.list ? NULL :
 641                 list_entry(p, struct gendisk, kobj.entry);
 642 }
 643
 644 static void diskstats_stop(struct seq_file *part, void *v)
 645 {
 646         mutex_unlock(&block_subsys_lock);
 647 }
 648
 649 static int diskstats_show(struct seq_file *s, void *v)
 650 {
 651         struct gendisk *gp = v;
 652         char buf[BDEVNAME_SIZE];
 653         int n = 0;
 654
 655         /*
 656         if (&sgp->kobj.entry == block_subsys.kset.list.next)
 657                 seq_puts(s,     "major minor name"
 658                                 "     rio rmerge rsect ruse wio wmerge "
 659                                 "wsect wuse running use aveq"
 660                                 "\n\n");
 661         */
 662
 663         preempt_disable();
 664         disk_round_stats(gp);
 665         preempt_enable();
 666         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 667                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 668                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 669                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 670                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 671                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 672                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 673                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 674                 gp->in_flight,
 675                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 676                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 677
 678         /* now show all non-0 size partitions of it */
 679         for (n = 0; n < gp->minors - 1; n++) {
 680                 struct hd_struct *hd = gp->part[n];
 681
 682                 if (hd && hd->nr_sects)
 683                         seq_printf(s, "%4d %4d %s %u %u %u %u\n",
 684                                 gp->major, n + gp->first_minor + 1,
 685                                 disk_name(gp, n + 1, buf),
 686                                 hd->ios[0], hd->sectors[0],
 687                                 hd->ios[1], hd->sectors[1]);
 688         }
 689
 690         return 0;
 691 }
 692
 693 struct seq_operations diskstats_op = {
 694         .start  = diskstats_start,
 695         .next   = diskstats_next,
 696         .stop   = diskstats_stop,
 697         .show   = diskstats_show
 698 };
 699
 700 static void media_change_notify_thread(struct work_struct *work)
 701 {
 702         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 703         char event[] = "MEDIA_CHANGE=1";
 704         char *envp[] = { event, NULL };
 705
 706         /*
 707          * set enviroment vars to indicate which event this is for
 708          * so that user space will know to go check the media status.
 709          */
 710         kobject_uevent_env(&gd->kobj, KOBJ_CHANGE, envp);
 711         put_device(gd->driverfs_dev);
 712 }
 713
 714 void genhd_media_change_notify(struct gendisk *disk)
 715 {
 716         get_device(disk->driverfs_dev);
 717         schedule_work(&disk->async_notify);
 718 }
 719 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 720
 721 struct gendisk *alloc_disk(int minors)
 722 {
 723         return alloc_disk_node(minors, -1);
 724 }
 725
 726 struct gendisk *alloc_disk_node(int minors, int node_id)
 727 {
 728         struct gendisk *disk;
 729
 730         disk = kmalloc_node(sizeof(struct gendisk),
 731                                 GFP_KERNEL | __GFP_ZERO, node_id);
 732         if (disk) {
 733                 if (!init_disk_stats(disk)) {
 734                         kfree(disk);
 735                         return NULL;
 736                 }
 737                 if (minors > 1) {
 738                         int size = (minors - 1) * sizeof(struct hd_struct *);
 739                         disk->part = kmalloc_node(size,
 740                                 GFP_KERNEL | __GFP_ZERO, node_id);
 741                         if (!disk->part) {
 742                                 kfree(disk);
 743                                 return NULL;
 744                         }
 745                 }
 746                 disk->minors = minors;
 747                 kobj_set_kset_s(disk,block_subsys);
 748                 kobject_init(&disk->kobj);
 749                 rand_initialize_disk(disk);
 750                 INIT_WORK(&disk->async_notify,
 751                         media_change_notify_thread);
 752         }
 753         return disk;
 754 }
 755
 756 EXPORT_SYMBOL(alloc_disk);
 757 EXPORT_SYMBOL(alloc_disk_node);
 758
 759 struct kobject *get_disk(struct gendisk *disk)
 760 {
 761         struct module *owner;
 762         struct kobject *kobj;
 763
 764         if (!disk->fops)
 765                 return NULL;
 766         owner = disk->fops->owner;
 767         if (owner && !try_module_get(owner))
 768                 return NULL;
 769         kobj = kobject_get(&disk->kobj);
 770         if (kobj == NULL) {
 771                 module_put(owner);
 772                 return NULL;
 773         }
 774         return kobj;
 775
 776 }
 777
 778 EXPORT_SYMBOL(get_disk);
 779
 780 void put_disk(struct gendisk *disk)
 781 {
 782         if (disk)
 783                 kobject_put(&disk->kobj);
 784 }
 785
 786 EXPORT_SYMBOL(put_disk);
 787
 788 void set_device_ro(struct block_device *bdev, int flag)
 789 {
 790         if (bdev->bd_contains != bdev)
 791                 bdev->bd_part->policy = flag;
 792         else
 793                 bdev->bd_disk->policy = flag;
 794 }
 795
 796 EXPORT_SYMBOL(set_device_ro);
 797
 798 void set_disk_ro(struct gendisk *disk, int flag)
 799 {
 800         int i;
 801         disk->policy = flag;
 802         for (i = 0; i < disk->minors - 1; i++)
 803                 if (disk->part[i]) disk->part[i]->policy = flag;
 804 }
 805
 806 EXPORT_SYMBOL(set_disk_ro);
 807
 808 int bdev_read_only(struct block_device *bdev)
 809 {
 810         if (!bdev)
 811                 return 0;
 812         else if (bdev->bd_contains != bdev)
 813                 return bdev->bd_part->policy;
 814         else
 815                 return bdev->bd_disk->policy;
 816 }
 817
 818 EXPORT_SYMBOL(bdev_read_only);
 819
 820 int invalidate_partition(struct gendisk *disk, int index)
 821 {
 822         int res = 0;
 823         struct block_device *bdev = bdget_disk(disk, index);
 824         if (bdev) {
 825                 fsync_bdev(bdev);
 826                 res = __invalidate_device(bdev);
 827                 bdput(bdev);
 828         }
 829         return res;
 830 }
 831
 832 EXPORT_SYMBOL(invalidate_partition);