block/genhd.c

   1 /*
   2  *  gendisk handling
   3  */
   4
   5 #include <linux/module.h>
   6 #include <linux/fs.h>
   7 #include <linux/genhd.h>
   8 #include <linux/kdev_t.h>
   9 #include <linux/kernel.h>
  10 #include <linux/blkdev.h>
  11 #include <linux/init.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/seq_file.h>
  14 #include <linux/slab.h>
  15 #include <linux/kmod.h>
  16 #include <linux/kobj_map.h>
  17 #include <linux/buffer_head.h>
  18 #include <linux/mutex.h>
  19
  20 #include "blk.h"
  21
  22 static DEFINE_MUTEX(block_class_lock);
  23 #ifndef CONFIG_SYSFS_DEPRECATED
  24 struct kobject *block_depr;
  25 #endif
  26
  27 static struct device_type disk_type;
  28
  29 /*
  30  * Can be deleted altogether. Later.
  31  *
  32  */
  33 static struct blk_major_name {
  34         struct blk_major_name *next;
  35         int major;
  36         char name[16];
  37 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
  38
  39 /* index in the above - for now: assume no multimajor ranges */
  40 static inline int major_to_index(int major)
  41 {
  42         return major % BLKDEV_MAJOR_HASH_SIZE;
  43 }
  44
  45 #ifdef CONFIG_PROC_FS
  46 void blkdev_show(struct seq_file *f, off_t offset)
  47 {
  48         struct blk_major_name *dp;
  49
  50         if (offset < BLKDEV_MAJOR_HASH_SIZE) {
  51                 mutex_lock(&block_class_lock);
  52                 for (dp = major_names[offset]; dp; dp = dp->next)
  53                         seq_printf(f, "%3d %s\n", dp->major, dp->name);
  54                 mutex_unlock(&block_class_lock);
  55         }
  56 }
  57 #endif /* CONFIG_PROC_FS */
  58
  59 int register_blkdev(unsigned int major, const char *name)
  60 {
  61         struct blk_major_name **n, *p;
  62         int index, ret = 0;
  63
  64         mutex_lock(&block_class_lock);
  65
  66         /* temporary */
  67         if (major == 0) {
  68                 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
  69                         if (major_names[index] == NULL)
  70                                 break;
  71                 }
  72
  73                 if (index == 0) {
  74                         printk("register_blkdev: failed to get major for %s\n",
  75                                name);
  76                         ret = -EBUSY;
  77                         goto out;
  78                 }
  79                 major = index;
  80                 ret = major;
  81         }
  82
  83         p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
  84         if (p == NULL) {
  85                 ret = -ENOMEM;
  86                 goto out;
  87         }
  88
  89         p->major = major;
  90         strlcpy(p->name, name, sizeof(p->name));
  91         p->next = NULL;
  92         index = major_to_index(major);
  93
  94         for (n = &major_names[index]; *n; n = &(*n)->next) {
  95                 if ((*n)->major == major)
  96                         break;
  97         }
  98         if (!*n)
  99                 *n = p;
 100         else
 101                 ret = -EBUSY;
 102
 103         if (ret < 0) {
 104                 printk("register_blkdev: cannot get major %d for %s\n",
 105                        major, name);
 106                 kfree(p);
 107         }
 108 out:
 109         mutex_unlock(&block_class_lock);
 110         return ret;
 111 }
 112
 113 EXPORT_SYMBOL(register_blkdev);
 114
 115 void unregister_blkdev(unsigned int major, const char *name)
 116 {
 117         struct blk_major_name **n;
 118         struct blk_major_name *p = NULL;
 119         int index = major_to_index(major);
 120
 121         mutex_lock(&block_class_lock);
 122         for (n = &major_names[index]; *n; n = &(*n)->next)
 123                 if ((*n)->major == major)
 124                         break;
 125         if (!*n || strcmp((*n)->name, name)) {
 126                 WARN_ON(1);
 127         } else {
 128                 p = *n;
 129                 *n = p->next;
 130         }
 131         mutex_unlock(&block_class_lock);
 132         kfree(p);
 133 }
 134
 135 EXPORT_SYMBOL(unregister_blkdev);
 136
 137 static struct kobj_map *bdev_map;
 138
 139 /*
 140  * Register device numbers dev..(dev+range-1)
 141  * range must be nonzero
 142  * The hash chain is sorted on range, so that subranges can override.
 143  */
 144 void blk_register_region(dev_t devt, unsigned long range, struct module *module,
 145                          struct kobject *(*probe)(dev_t, int *, void *),
 146                          int (*lock)(dev_t, void *), void *data)
 147 {
 148         kobj_map(bdev_map, devt, range, module, probe, lock, data);
 149 }
 150
 151 EXPORT_SYMBOL(blk_register_region);
 152
 153 void blk_unregister_region(dev_t devt, unsigned long range)
 154 {
 155         kobj_unmap(bdev_map, devt, range);
 156 }
 157
 158 EXPORT_SYMBOL(blk_unregister_region);
 159
 160 static struct kobject *exact_match(dev_t devt, int *part, void *data)
 161 {
 162         struct gendisk *p = data;
 163
 164         return &p->dev.kobj;
 165 }
 166
 167 static int exact_lock(dev_t devt, void *data)
 168 {
 169         struct gendisk *p = data;
 170
 171         if (!get_disk(p))
 172                 return -1;
 173         return 0;
 174 }
 175
 176 /**
 177  * add_disk - add partitioning information to kernel list
 178  * @disk: per-device partitioning information
 179  *
 180  * This function registers the partitioning information in @disk
 181  * with the kernel.
 182  */
 183 void add_disk(struct gendisk *disk)
 184 {
 185         struct backing_dev_info *bdi;
 186         int retval;
 187
 188         disk->flags |= GENHD_FL_UP;
 189         blk_register_region(MKDEV(disk->major, disk->first_minor),
 190                             disk->minors, NULL, exact_match, exact_lock, disk);
 191         register_disk(disk);
 192         blk_register_queue(disk);
 193         blk_register_filter(disk);
 194
 195         bdi = &disk->queue->backing_dev_info;
 196         bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor));
 197         retval = sysfs_create_link(&disk->dev.kobj, &bdi->dev->kobj, "bdi");
 198         WARN_ON(retval);
 199 }
 200
 201 EXPORT_SYMBOL(add_disk);
 202 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 203
 204 void unlink_gendisk(struct gendisk *disk)
 205 {
 206         blk_unregister_filter(disk);
 207         sysfs_remove_link(&disk->dev.kobj, "bdi");
 208         bdi_unregister(&disk->queue->backing_dev_info);
 209         blk_unregister_queue(disk);
 210         blk_unregister_region(MKDEV(disk->major, disk->first_minor),
 211                               disk->minors);
 212 }
 213
 214 /**
 215  * get_gendisk - get partitioning information for a given device
 216  * @dev: device to get partitioning information for
 217  *
 218  * This function gets the structure containing partitioning
 219  * information for the given device @dev.
 220  */
 221 struct gendisk *get_gendisk(dev_t devt, int *part)
 222 {
 223         struct kobject *kobj = kobj_lookup(bdev_map, devt, part);
 224         struct device *dev = kobj_to_dev(kobj);
 225
 226         return  kobj ? dev_to_disk(dev) : NULL;
 227 }
 228
 229 /*
 230  * print a partitions - intended for places where the root filesystem can't be
 231  * mounted and thus to give the victim some idea of what went wrong
 232  */
 233 static int printk_partition(struct device *dev, void *data)
 234 {
 235         struct gendisk *sgp;
 236         char buf[BDEVNAME_SIZE];
 237         int n;
 238
 239         if (dev->type != &disk_type)
 240                 goto exit;
 241
 242         sgp = dev_to_disk(dev);
 243         /*
 244          * Don't show empty devices or things that have been surpressed
 245          */
 246         if (get_capacity(sgp) == 0 ||
 247             (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 248                 goto exit;
 249
 250         /*
 251          * Note, unlike /proc/partitions, I am showing the numbers in
 252          * hex - the same format as the root= option takes.
 253          */
 254         printk("%02x%02x %10llu %s",
 255                 sgp->major, sgp->first_minor,
 256                 (unsigned long long)get_capacity(sgp) >> 1,
 257                 disk_name(sgp, 0, buf));
 258         if (sgp->driverfs_dev != NULL &&
 259             sgp->driverfs_dev->driver != NULL)
 260                 printk(" driver: %s\n",
 261                         sgp->driverfs_dev->driver->name);
 262         else
 263                 printk(" (driver?)\n");
 264
 265         /* now show the partitions */
 266         for (n = 0; n < sgp->minors - 1; ++n) {
 267                 if (sgp->part[n] == NULL)
 268                         goto exit;
 269                 if (sgp->part[n]->nr_sects == 0)
 270                         goto exit;
 271                 printk("  %02x%02x %10llu %s\n",
 272                         sgp->major, n + 1 + sgp->first_minor,
 273                         (unsigned long long)sgp->part[n]->nr_sects >> 1,
 274                         disk_name(sgp, n + 1, buf));
 275         }
 276 exit:
 277         return 0;
 278 }
 279
 280 /*
 281  * print a full list of all partitions - intended for places where the root
 282  * filesystem can't be mounted and thus to give the victim some idea of what
 283  * went wrong
 284  */
 285 void __init printk_all_partitions(void)
 286 {
 287         mutex_lock(&block_class_lock);
 288         class_for_each_device(&block_class, NULL, NULL, printk_partition);
 289         mutex_unlock(&block_class_lock);
 290 }
 291
 292 #ifdef CONFIG_PROC_FS
 293 /* iterator */
 294 static int find_start(struct device *dev, void *data)
 295 {
 296         loff_t *k = data;
 297
 298         if (dev->type != &disk_type)
 299                 return 0;
 300         if (!*k)
 301                 return 1;
 302         (*k)--;
 303         return 0;
 304 }
 305
 306 static void *part_start(struct seq_file *part, loff_t *pos)
 307 {
 308         struct device *dev;
 309         loff_t k = *pos;
 310
 311         if (!k)
 312                 seq_puts(part, "major minor  #blocks  name\n\n");
 313
 314         mutex_lock(&block_class_lock);
 315         dev = class_find_device(&block_class, NULL, &k, find_start);
 316         if (dev) {
 317                 put_device(dev);
 318                 return dev_to_disk(dev);
 319         }
 320         return NULL;
 321 }
 322
 323 static int find_next(struct device *dev, void *data)
 324 {
 325         if (dev->type == &disk_type)
 326                 return 1;
 327         return 0;
 328 }
 329
 330 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 331 {
 332         struct gendisk *gp = v;
 333         struct device *dev;
 334         ++*pos;
 335         dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
 336         if (dev) {
 337                 put_device(dev);
 338                 return dev_to_disk(dev);
 339         }
 340         return NULL;
 341 }
 342
 343 static void part_stop(struct seq_file *part, void *v)
 344 {
 345         mutex_unlock(&block_class_lock);
 346 }
 347
 348 static int show_partition(struct seq_file *part, void *v)
 349 {
 350         struct gendisk *sgp = v;
 351         int n;
 352         char buf[BDEVNAME_SIZE];
 353
 354         /* Don't show non-partitionable removeable devices or empty devices */
 355         if (!get_capacity(sgp) ||
 356                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 357                 return 0;
 358         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 359                 return 0;
 360
 361         /* show the full disk and all non-0 size partitions of it */
 362         seq_printf(part, "%4d  %4d %10llu %s\n",
 363                 sgp->major, sgp->first_minor,
 364                 (unsigned long long)get_capacity(sgp) >> 1,
 365                 disk_name(sgp, 0, buf));
 366         for (n = 0; n < sgp->minors - 1; n++) {
 367                 if (!sgp->part[n])
 368                         continue;
 369                 if (sgp->part[n]->nr_sects == 0)
 370                         continue;
 371                 seq_printf(part, "%4d  %4d %10llu %s\n",
 372                         sgp->major, n + 1 + sgp->first_minor,
 373                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 374                         disk_name(sgp, n + 1, buf));
 375         }
 376
 377         return 0;
 378 }
 379
 380 const struct seq_operations partitions_op = {
 381         .start  = part_start,
 382         .next   = part_next,
 383         .stop   = part_stop,
 384         .show   = show_partition
 385 };
 386 #endif
 387
 388
 389 static struct kobject *base_probe(dev_t devt, int *part, void *data)
 390 {
 391         if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
 392                 /* Make old-style 2.4 aliases work */
 393                 request_module("block-major-%d", MAJOR(devt));
 394         return NULL;
 395 }
 396
 397 static int __init genhd_device_init(void)
 398 {
 399         int error;
 400
 401         block_class.dev_kobj = sysfs_dev_block_kobj;
 402         error = class_register(&block_class);
 403         if (unlikely(error))
 404                 return error;
 405         bdev_map = kobj_map_init(base_probe, &block_class_lock);
 406         blk_dev_init();
 407
 408 #ifndef CONFIG_SYSFS_DEPRECATED
 409         /* create top-level block dir */
 410         block_depr = kobject_create_and_add("block", NULL);
 411 #endif
 412         return 0;
 413 }
 414
 415 subsys_initcall(genhd_device_init);
 416
 417 static ssize_t disk_range_show(struct device *dev,
 418                                struct device_attribute *attr, char *buf)
 419 {
 420         struct gendisk *disk = dev_to_disk(dev);
 421
 422         return sprintf(buf, "%d\n", disk->minors);
 423 }
 424
 425 static ssize_t disk_removable_show(struct device *dev,
 426                                    struct device_attribute *attr, char *buf)
 427 {
 428         struct gendisk *disk = dev_to_disk(dev);
 429
 430         return sprintf(buf, "%d\n",
 431                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 432 }
 433
 434 static ssize_t disk_ro_show(struct device *dev,
 435                                    struct device_attribute *attr, char *buf)
 436 {
 437         struct gendisk *disk = dev_to_disk(dev);
 438
 439         return sprintf(buf, "%d\n", disk->policy ? 1 : 0);
 440 }
 441
 442 static ssize_t disk_size_show(struct device *dev,
 443                               struct device_attribute *attr, char *buf)
 444 {
 445         struct gendisk *disk = dev_to_disk(dev);
 446
 447         return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
 448 }
 449
 450 static ssize_t disk_capability_show(struct device *dev,
 451                                     struct device_attribute *attr, char *buf)
 452 {
 453         struct gendisk *disk = dev_to_disk(dev);
 454
 455         return sprintf(buf, "%x\n", disk->flags);
 456 }
 457
 458 static ssize_t disk_stat_show(struct device *dev,
 459                               struct device_attribute *attr, char *buf)
 460 {
 461         struct gendisk *disk = dev_to_disk(dev);
 462
 463         preempt_disable();
 464         disk_round_stats(disk);
 465         preempt_enable();
 466         return sprintf(buf,
 467                 "%8lu %8lu %8llu %8u "
 468                 "%8lu %8lu %8llu %8u "
 469                 "%8u %8u %8u"
 470                 "\n",
 471                 disk_stat_read(disk, ios[READ]),
 472                 disk_stat_read(disk, merges[READ]),
 473                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 474                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 475                 disk_stat_read(disk, ios[WRITE]),
 476                 disk_stat_read(disk, merges[WRITE]),
 477                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 478                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 479                 disk->in_flight,
 480                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 481                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 482 }
 483
 484 #ifdef CONFIG_FAIL_MAKE_REQUEST
 485 static ssize_t disk_fail_show(struct device *dev,
 486                               struct device_attribute *attr, char *buf)
 487 {
 488         struct gendisk *disk = dev_to_disk(dev);
 489
 490         return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 491 }
 492
 493 static ssize_t disk_fail_store(struct device *dev,
 494                                struct device_attribute *attr,
 495                                const char *buf, size_t count)
 496 {
 497         struct gendisk *disk = dev_to_disk(dev);
 498         int i;
 499
 500         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 501                 if (i == 0)
 502                         disk->flags &= ~GENHD_FL_FAIL;
 503                 else
 504                         disk->flags |= GENHD_FL_FAIL;
 505         }
 506
 507         return count;
 508 }
 509
 510 #endif
 511
 512 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 513 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
 514 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
 515 static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
 516 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
 517 static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
 518 #ifdef CONFIG_FAIL_MAKE_REQUEST
 519 static struct device_attribute dev_attr_fail =
 520         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
 521 #endif
 522
 523 static struct attribute *disk_attrs[] = {
 524         &dev_attr_range.attr,
 525         &dev_attr_removable.attr,
 526         &dev_attr_ro.attr,
 527         &dev_attr_size.attr,
 528         &dev_attr_capability.attr,
 529         &dev_attr_stat.attr,
 530 #ifdef CONFIG_FAIL_MAKE_REQUEST
 531         &dev_attr_fail.attr,
 532 #endif
 533         NULL
 534 };
 535
 536 static struct attribute_group disk_attr_group = {
 537         .attrs = disk_attrs,
 538 };
 539
 540 static struct attribute_group *disk_attr_groups[] = {
 541         &disk_attr_group,
 542         NULL
 543 };
 544
 545 static void disk_release(struct device *dev)
 546 {
 547         struct gendisk *disk = dev_to_disk(dev);
 548
 549         kfree(disk->random);
 550         kfree(disk->part);
 551         free_disk_stats(disk);
 552         kfree(disk);
 553 }
 554 struct class block_class = {
 555         .name           = "block",
 556 };
 557
 558 static struct device_type disk_type = {
 559         .name           = "disk",
 560         .groups         = disk_attr_groups,
 561         .release        = disk_release,
 562 };
 563
 564 #ifdef CONFIG_PROC_FS
 565 /*
 566  * aggregate disk stat collector.  Uses the same stats that the sysfs
 567  * entries do, above, but makes them available through one seq_file.
 568  *
 569  * The output looks suspiciously like /proc/partitions with a bunch of
 570  * extra fields.
 571  */
 572
 573 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 574 {
 575         struct device *dev;
 576         loff_t k = *pos;
 577
 578         mutex_lock(&block_class_lock);
 579         dev = class_find_device(&block_class, NULL, &k, find_start);
 580         if (dev) {
 581                 put_device(dev);
 582                 return dev_to_disk(dev);
 583         }
 584         return NULL;
 585 }
 586
 587 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 588 {
 589         struct gendisk *gp = v;
 590         struct device *dev;
 591
 592         ++*pos;
 593         dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
 594         if (dev) {
 595                 put_device(dev);
 596                 return dev_to_disk(dev);
 597         }
 598         return NULL;
 599 }
 600
 601 static void diskstats_stop(struct seq_file *part, void *v)
 602 {
 603         mutex_unlock(&block_class_lock);
 604 }
 605
 606 static int diskstats_show(struct seq_file *s, void *v)
 607 {
 608         struct gendisk *gp = v;
 609         char buf[BDEVNAME_SIZE];
 610         int n = 0;
 611
 612         /*
 613         if (&gp->dev.kobj.entry == block_class.devices.next)
 614                 seq_puts(s,     "major minor name"
 615                                 "     rio rmerge rsect ruse wio wmerge "
 616                                 "wsect wuse running use aveq"
 617                                 "\n\n");
 618         */
 619
 620         preempt_disable();
 621         disk_round_stats(gp);
 622         preempt_enable();
 623         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 624                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 625                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 626                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 627                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 628                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 629                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 630                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 631                 gp->in_flight,
 632                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 633                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 634
 635         /* now show all non-0 size partitions of it */
 636         for (n = 0; n < gp->minors - 1; n++) {
 637                 struct hd_struct *hd = gp->part[n];
 638
 639                 if (!hd || !hd->nr_sects)
 640                         continue;
 641
 642                 preempt_disable();
 643                 part_round_stats(hd);
 644                 preempt_enable();
 645                 seq_printf(s, "%4d %4d %s %lu %lu %llu "
 646                            "%u %lu %lu %llu %u %u %u %u\n",
 647                            gp->major, n + gp->first_minor + 1,
 648                            disk_name(gp, n + 1, buf),
 649                            part_stat_read(hd, ios[0]),
 650                            part_stat_read(hd, merges[0]),
 651                            (unsigned long long)part_stat_read(hd, sectors[0]),
 652                            jiffies_to_msecs(part_stat_read(hd, ticks[0])),
 653                            part_stat_read(hd, ios[1]),
 654                            part_stat_read(hd, merges[1]),
 655                            (unsigned long long)part_stat_read(hd, sectors[1]),
 656                            jiffies_to_msecs(part_stat_read(hd, ticks[1])),
 657                            hd->in_flight,
 658                            jiffies_to_msecs(part_stat_read(hd, io_ticks)),
 659                            jiffies_to_msecs(part_stat_read(hd, time_in_queue))
 660                         );
 661         }
 662
 663         return 0;
 664 }
 665
 666 const struct seq_operations diskstats_op = {
 667         .start  = diskstats_start,
 668         .next   = diskstats_next,
 669         .stop   = diskstats_stop,
 670         .show   = diskstats_show
 671 };
 672 #endif /* CONFIG_PROC_FS */
 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->dev.kobj, KOBJ_CHANGE, envp);
 685         put_device(gd->driverfs_dev);
 686 }
 687
 688 #if 0
 689 void genhd_media_change_notify(struct gendisk *disk)
 690 {
 691         get_device(disk->driverfs_dev);
 692         schedule_work(&disk->async_notify);
 693 }
 694 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 695 #endif  /*  0  */
 696
 697 struct find_block {
 698         const char *name;
 699         int part;
 700 };
 701
 702 static int match_id(struct device *dev, void *data)
 703 {
 704         struct find_block *find = data;
 705
 706         if (dev->type != &disk_type)
 707                 return 0;
 708         if (strcmp(dev->bus_id, find->name) == 0) {
 709                 struct gendisk *disk = dev_to_disk(dev);
 710                 if (find->part < disk->minors)
 711                         return 1;
 712         }
 713         return 0;
 714 }
 715
 716 dev_t blk_lookup_devt(const char *name, int part)
 717 {
 718         struct device *dev;
 719         dev_t devt = MKDEV(0, 0);
 720         struct find_block find;
 721
 722         mutex_lock(&block_class_lock);
 723         find.name = name;
 724         find.part = part;
 725         dev = class_find_device(&block_class, NULL, &find, match_id);
 726         if (dev) {
 727                 put_device(dev);
 728                 devt = MKDEV(MAJOR(dev->devt),
 729                              MINOR(dev->devt) + part);
 730         }
 731         mutex_unlock(&block_class_lock);
 732
 733         return devt;
 734 }
 735 EXPORT_SYMBOL(blk_lookup_devt);
 736
 737 struct gendisk *alloc_disk(int minors)
 738 {
 739         return alloc_disk_node(minors, -1);
 740 }
 741
 742 struct gendisk *alloc_disk_node(int minors, int node_id)
 743 {
 744         struct gendisk *disk;
 745
 746         disk = kmalloc_node(sizeof(struct gendisk),
 747                                 GFP_KERNEL | __GFP_ZERO, node_id);
 748         if (disk) {
 749                 if (!init_disk_stats(disk)) {
 750                         kfree(disk);
 751                         return NULL;
 752                 }
 753                 if (minors > 1) {
 754                         int size = (minors - 1) * sizeof(struct hd_struct *);
 755                         disk->part = kmalloc_node(size,
 756                                 GFP_KERNEL | __GFP_ZERO, node_id);
 757                         if (!disk->part) {
 758                                 free_disk_stats(disk);
 759                                 kfree(disk);
 760                                 return NULL;
 761                         }
 762                 }
 763                 disk->minors = minors;
 764                 rand_initialize_disk(disk);
 765                 disk->dev.class = &block_class;
 766                 disk->dev.type = &disk_type;
 767                 device_initialize(&disk->dev);
 768                 INIT_WORK(&disk->async_notify,
 769                         media_change_notify_thread);
 770         }
 771         return disk;
 772 }
 773
 774 EXPORT_SYMBOL(alloc_disk);
 775 EXPORT_SYMBOL(alloc_disk_node);
 776
 777 struct kobject *get_disk(struct gendisk *disk)
 778 {
 779         struct module *owner;
 780         struct kobject *kobj;
 781
 782         if (!disk->fops)
 783                 return NULL;
 784         owner = disk->fops->owner;
 785         if (owner && !try_module_get(owner))
 786                 return NULL;
 787         kobj = kobject_get(&disk->dev.kobj);
 788         if (kobj == NULL) {
 789                 module_put(owner);
 790                 return NULL;
 791         }
 792         return kobj;
 793
 794 }
 795
 796 EXPORT_SYMBOL(get_disk);
 797
 798 void put_disk(struct gendisk *disk)
 799 {
 800         if (disk)
 801                 kobject_put(&disk->dev.kobj);
 802 }
 803
 804 EXPORT_SYMBOL(put_disk);
 805
 806 void set_device_ro(struct block_device *bdev, int flag)
 807 {
 808         if (bdev->bd_contains != bdev)
 809                 bdev->bd_part->policy = flag;
 810         else
 811                 bdev->bd_disk->policy = flag;
 812 }
 813
 814 EXPORT_SYMBOL(set_device_ro);
 815
 816 void set_disk_ro(struct gendisk *disk, int flag)
 817 {
 818         int i;
 819         disk->policy = flag;
 820         for (i = 0; i < disk->minors - 1; i++)
 821                 if (disk->part[i]) disk->part[i]->policy = flag;
 822 }
 823
 824 EXPORT_SYMBOL(set_disk_ro);
 825
 826 int bdev_read_only(struct block_device *bdev)
 827 {
 828         if (!bdev)
 829                 return 0;
 830         else if (bdev->bd_contains != bdev)
 831                 return bdev->bd_part->policy;
 832         else
 833                 return bdev->bd_disk->policy;
 834 }
 835
 836 EXPORT_SYMBOL(bdev_read_only);
 837
 838 int invalidate_partition(struct gendisk *disk, int index)
 839 {
 840         int res = 0;
 841         struct block_device *bdev = bdget_disk(disk, index);
 842         if (bdev) {
 843                 fsync_bdev(bdev);
 844                 res = __invalidate_device(bdev);
 845                 bdput(bdev);
 846         }
 847         return res;
 848 }
 849
 850 EXPORT_SYMBOL(invalidate_partition);