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
 194         bdi = &disk->queue->backing_dev_info;
 195         bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor));
 196         retval = sysfs_create_link(&disk->dev.kobj, &bdi->dev->kobj, "bdi");
 197         WARN_ON(retval);
 198 }
 199
 200 EXPORT_SYMBOL(add_disk);
 201 EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 202
 203 void unlink_gendisk(struct gendisk *disk)
 204 {
 205         sysfs_remove_link(&disk->dev.kobj, "bdi");
 206         bdi_unregister(&disk->queue->backing_dev_info);
 207         blk_unregister_queue(disk);
 208         blk_unregister_region(MKDEV(disk->major, disk->first_minor),
 209                               disk->minors);
 210 }
 211
 212 /**
 213  * get_gendisk - get partitioning information for a given device
 214  * @devt: device to get partitioning information for
 215  * @part: returned partition index
 216  *
 217  * This function gets the structure containing partitioning
 218  * information for the given device @devt.
 219  */
 220 struct gendisk *get_gendisk(dev_t devt, int *part)
 221 {
 222         struct kobject *kobj = kobj_lookup(bdev_map, devt, part);
 223         struct device *dev = kobj_to_dev(kobj);
 224
 225         return  kobj ? dev_to_disk(dev) : NULL;
 226 }
 227
 228 /*
 229  * print a partitions - intended for places where the root filesystem can't be
 230  * mounted and thus to give the victim some idea of what went wrong
 231  */
 232 static int printk_partition(struct device *dev, void *data)
 233 {
 234         struct gendisk *sgp;
 235         char buf[BDEVNAME_SIZE];
 236         int n;
 237
 238         if (dev->type != &disk_type)
 239                 return 0;
 240
 241         sgp = dev_to_disk(dev);
 242         /*
 243          * Don't show empty devices or things that have been surpressed
 244          */
 245         if (get_capacity(sgp) == 0 ||
 246             (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 247                 return 0;
 248
 249         /*
 250          * Note, unlike /proc/partitions, I am showing the numbers in
 251          * hex - the same format as the root= option takes.
 252          */
 253         printk("%02x%02x %10llu %s",
 254                 sgp->major, sgp->first_minor,
 255                 (unsigned long long)get_capacity(sgp) >> 1,
 256                 disk_name(sgp, 0, buf));
 257         if (sgp->driverfs_dev != NULL &&
 258             sgp->driverfs_dev->driver != NULL)
 259                 printk(" driver: %s\n",
 260                         sgp->driverfs_dev->driver->name);
 261         else
 262                 printk(" (driver?)\n");
 263
 264         /* now show the partitions */
 265         for (n = 0; n < sgp->minors - 1; ++n) {
 266                 if (sgp->part[n] == NULL)
 267                         continue;
 268                 if (sgp->part[n]->nr_sects == 0)
 269                         continue;
 270                 printk("  %02x%02x %10llu %s\n",
 271                         sgp->major, n + 1 + sgp->first_minor,
 272                         (unsigned long long)sgp->part[n]->nr_sects >> 1,
 273                         disk_name(sgp, n + 1, buf));
 274         }
 275
 276         return 0;
 277 }
 278
 279 /*
 280  * print a full list of all partitions - intended for places where the root
 281  * filesystem can't be mounted and thus to give the victim some idea of what
 282  * went wrong
 283  */
 284 void __init printk_all_partitions(void)
 285 {
 286         class_for_each_device(&block_class, NULL, NULL, printk_partition);
 287 }
 288
 289 #ifdef CONFIG_PROC_FS
 290 /* iterator */
 291 static int find_start(struct device *dev, void *data)
 292 {
 293         loff_t *k = data;
 294
 295         if (dev->type != &disk_type)
 296                 return 0;
 297         if (!*k)
 298                 return 1;
 299         (*k)--;
 300         return 0;
 301 }
 302
 303 static void *part_start(struct seq_file *part, loff_t *pos)
 304 {
 305         struct device *dev;
 306         loff_t n = *pos;
 307
 308         if (!n)
 309                 part->private = (void *)1LU;    /* tell show to print header */
 310
 311         dev = class_find_device(&block_class, NULL, &n, find_start);
 312         if (dev)
 313                 return dev_to_disk(dev);
 314
 315         return NULL;
 316 }
 317
 318 static int find_next(struct device *dev, void *data)
 319 {
 320         if (dev->type == &disk_type)
 321                 return 1;
 322         return 0;
 323 }
 324
 325 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
 326 {
 327         struct gendisk *gp = v;
 328         struct device *dev;
 329         ++*pos;
 330         dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
 331         if (dev) {
 332                 put_device(dev);
 333                 return dev_to_disk(dev);
 334         }
 335         return NULL;
 336 }
 337
 338 static void part_stop(struct seq_file *part, void *v)
 339 {
 340 }
 341
 342 static int show_partition(struct seq_file *part, void *v)
 343 {
 344         struct gendisk *sgp = v;
 345         int n;
 346         char buf[BDEVNAME_SIZE];
 347
 348         /*
 349          * Print header if start told us to do.  This is to preserve
 350          * the original behavior of not printing header if no
 351          * partition exists.  This hackery will be removed later with
 352          * class iteration clean up.
 353          */
 354         if (part->private) {
 355                 seq_puts(part, "major minor  #blocks  name\n\n");
 356                 part->private = NULL;
 357         }
 358
 359         /* Don't show non-partitionable removeable devices or empty devices */
 360         if (!get_capacity(sgp) ||
 361                         (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
 362                 return 0;
 363         if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 364                 return 0;
 365
 366         /* show the full disk and all non-0 size partitions of it */
 367         seq_printf(part, "%4d  %4d %10llu %s\n",
 368                 sgp->major, sgp->first_minor,
 369                 (unsigned long long)get_capacity(sgp) >> 1,
 370                 disk_name(sgp, 0, buf));
 371         for (n = 0; n < sgp->minors - 1; n++) {
 372                 if (!sgp->part[n])
 373                         continue;
 374                 if (sgp->part[n]->nr_sects == 0)
 375                         continue;
 376                 seq_printf(part, "%4d  %4d %10llu %s\n",
 377                         sgp->major, n + 1 + sgp->first_minor,
 378                         (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
 379                         disk_name(sgp, n + 1, buf));
 380         }
 381
 382         return 0;
 383 }
 384
 385 const struct seq_operations partitions_op = {
 386         .start  = part_start,
 387         .next   = part_next,
 388         .stop   = part_stop,
 389         .show   = show_partition
 390 };
 391 #endif
 392
 393
 394 static struct kobject *base_probe(dev_t devt, int *part, void *data)
 395 {
 396         if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
 397                 /* Make old-style 2.4 aliases work */
 398                 request_module("block-major-%d", MAJOR(devt));
 399         return NULL;
 400 }
 401
 402 static int __init genhd_device_init(void)
 403 {
 404         int error;
 405
 406         block_class.dev_kobj = sysfs_dev_block_kobj;
 407         error = class_register(&block_class);
 408         if (unlikely(error))
 409                 return error;
 410         bdev_map = kobj_map_init(base_probe, &block_class_lock);
 411         blk_dev_init();
 412
 413 #ifndef CONFIG_SYSFS_DEPRECATED
 414         /* create top-level block dir */
 415         block_depr = kobject_create_and_add("block", NULL);
 416 #endif
 417         return 0;
 418 }
 419
 420 subsys_initcall(genhd_device_init);
 421
 422 static ssize_t disk_range_show(struct device *dev,
 423                                struct device_attribute *attr, char *buf)
 424 {
 425         struct gendisk *disk = dev_to_disk(dev);
 426
 427         return sprintf(buf, "%d\n", disk->minors);
 428 }
 429
 430 static ssize_t disk_removable_show(struct device *dev,
 431                                    struct device_attribute *attr, char *buf)
 432 {
 433         struct gendisk *disk = dev_to_disk(dev);
 434
 435         return sprintf(buf, "%d\n",
 436                        (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 437 }
 438
 439 static ssize_t disk_ro_show(struct device *dev,
 440                                    struct device_attribute *attr, char *buf)
 441 {
 442         struct gendisk *disk = dev_to_disk(dev);
 443
 444         return sprintf(buf, "%d\n", disk->policy ? 1 : 0);
 445 }
 446
 447 static ssize_t disk_size_show(struct device *dev,
 448                               struct device_attribute *attr, char *buf)
 449 {
 450         struct gendisk *disk = dev_to_disk(dev);
 451
 452         return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
 453 }
 454
 455 static ssize_t disk_capability_show(struct device *dev,
 456                                     struct device_attribute *attr, char *buf)
 457 {
 458         struct gendisk *disk = dev_to_disk(dev);
 459
 460         return sprintf(buf, "%x\n", disk->flags);
 461 }
 462
 463 static ssize_t disk_stat_show(struct device *dev,
 464                               struct device_attribute *attr, char *buf)
 465 {
 466         struct gendisk *disk = dev_to_disk(dev);
 467
 468         preempt_disable();
 469         disk_round_stats(disk);
 470         preempt_enable();
 471         return sprintf(buf,
 472                 "%8lu %8lu %8llu %8u "
 473                 "%8lu %8lu %8llu %8u "
 474                 "%8u %8u %8u"
 475                 "\n",
 476                 disk_stat_read(disk, ios[READ]),
 477                 disk_stat_read(disk, merges[READ]),
 478                 (unsigned long long)disk_stat_read(disk, sectors[READ]),
 479                 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
 480                 disk_stat_read(disk, ios[WRITE]),
 481                 disk_stat_read(disk, merges[WRITE]),
 482                 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
 483                 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
 484                 disk->in_flight,
 485                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
 486                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
 487 }
 488
 489 #ifdef CONFIG_FAIL_MAKE_REQUEST
 490 static ssize_t disk_fail_show(struct device *dev,
 491                               struct device_attribute *attr, char *buf)
 492 {
 493         struct gendisk *disk = dev_to_disk(dev);
 494
 495         return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
 496 }
 497
 498 static ssize_t disk_fail_store(struct device *dev,
 499                                struct device_attribute *attr,
 500                                const char *buf, size_t count)
 501 {
 502         struct gendisk *disk = dev_to_disk(dev);
 503         int i;
 504
 505         if (count > 0 && sscanf(buf, "%d", &i) > 0) {
 506                 if (i == 0)
 507                         disk->flags &= ~GENHD_FL_FAIL;
 508                 else
 509                         disk->flags |= GENHD_FL_FAIL;
 510         }
 511
 512         return count;
 513 }
 514
 515 #endif
 516
 517 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 518 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
 519 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
 520 static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
 521 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
 522 static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
 523 #ifdef CONFIG_FAIL_MAKE_REQUEST
 524 static struct device_attribute dev_attr_fail =
 525         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
 526 #endif
 527
 528 static struct attribute *disk_attrs[] = {
 529         &dev_attr_range.attr,
 530         &dev_attr_removable.attr,
 531         &dev_attr_ro.attr,
 532         &dev_attr_size.attr,
 533         &dev_attr_capability.attr,
 534         &dev_attr_stat.attr,
 535 #ifdef CONFIG_FAIL_MAKE_REQUEST
 536         &dev_attr_fail.attr,
 537 #endif
 538         NULL
 539 };
 540
 541 static struct attribute_group disk_attr_group = {
 542         .attrs = disk_attrs,
 543 };
 544
 545 static struct attribute_group *disk_attr_groups[] = {
 546         &disk_attr_group,
 547         NULL
 548 };
 549
 550 static void disk_release(struct device *dev)
 551 {
 552         struct gendisk *disk = dev_to_disk(dev);
 553
 554         kfree(disk->random);
 555         kfree(disk->part);
 556         free_disk_stats(disk);
 557         kfree(disk);
 558 }
 559 struct class block_class = {
 560         .name           = "block",
 561 };
 562
 563 static struct device_type disk_type = {
 564         .name           = "disk",
 565         .groups         = disk_attr_groups,
 566         .release        = disk_release,
 567 };
 568
 569 #ifdef CONFIG_PROC_FS
 570 /*
 571  * aggregate disk stat collector.  Uses the same stats that the sysfs
 572  * entries do, above, but makes them available through one seq_file.
 573  *
 574  * The output looks suspiciously like /proc/partitions with a bunch of
 575  * extra fields.
 576  */
 577
 578 static void *diskstats_start(struct seq_file *part, loff_t *pos)
 579 {
 580         struct device *dev;
 581         loff_t n = *pos;
 582
 583         dev = class_find_device(&block_class, NULL, &n, find_start);
 584         if (dev)
 585                 return dev_to_disk(dev);
 586
 587         return NULL;
 588 }
 589
 590 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
 591 {
 592         struct gendisk *gp = v;
 593         struct device *dev;
 594
 595         ++*pos;
 596         dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
 597         if (dev) {
 598                 put_device(dev);
 599                 return dev_to_disk(dev);
 600         }
 601         return NULL;
 602 }
 603
 604 static void diskstats_stop(struct seq_file *part, void *v)
 605 {
 606 }
 607
 608 static int diskstats_show(struct seq_file *s, void *v)
 609 {
 610         struct gendisk *gp = v;
 611         char buf[BDEVNAME_SIZE];
 612         int n = 0;
 613
 614         /*
 615         if (&gp->dev.kobj.entry == block_class.devices.next)
 616                 seq_puts(s,     "major minor name"
 617                                 "     rio rmerge rsect ruse wio wmerge "
 618                                 "wsect wuse running use aveq"
 619                                 "\n\n");
 620         */
 621
 622         preempt_disable();
 623         disk_round_stats(gp);
 624         preempt_enable();
 625         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
 626                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
 627                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
 628                 (unsigned long long)disk_stat_read(gp, sectors[0]),
 629                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
 630                 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
 631                 (unsigned long long)disk_stat_read(gp, sectors[1]),
 632                 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
 633                 gp->in_flight,
 634                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
 635                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
 636
 637         /* now show all non-0 size partitions of it */
 638         for (n = 0; n < gp->minors - 1; n++) {
 639                 struct hd_struct *hd = gp->part[n];
 640
 641                 if (!hd || !hd->nr_sects)
 642                         continue;
 643
 644                 preempt_disable();
 645                 part_round_stats(hd);
 646                 preempt_enable();
 647                 seq_printf(s, "%4d %4d %s %lu %lu %llu "
 648                            "%u %lu %lu %llu %u %u %u %u\n",
 649                            gp->major, n + gp->first_minor + 1,
 650                            disk_name(gp, n + 1, buf),
 651                            part_stat_read(hd, ios[0]),
 652                            part_stat_read(hd, merges[0]),
 653                            (unsigned long long)part_stat_read(hd, sectors[0]),
 654                            jiffies_to_msecs(part_stat_read(hd, ticks[0])),
 655                            part_stat_read(hd, ios[1]),
 656                            part_stat_read(hd, merges[1]),
 657                            (unsigned long long)part_stat_read(hd, sectors[1]),
 658                            jiffies_to_msecs(part_stat_read(hd, ticks[1])),
 659                            hd->in_flight,
 660                            jiffies_to_msecs(part_stat_read(hd, io_ticks)),
 661                            jiffies_to_msecs(part_stat_read(hd, time_in_queue))
 662                         );
 663         }
 664
 665         return 0;
 666 }
 667
 668 const struct seq_operations diskstats_op = {
 669         .start  = diskstats_start,
 670         .next   = diskstats_next,
 671         .stop   = diskstats_stop,
 672         .show   = diskstats_show
 673 };
 674 #endif /* CONFIG_PROC_FS */
 675
 676 static void media_change_notify_thread(struct work_struct *work)
 677 {
 678         struct gendisk *gd = container_of(work, struct gendisk, async_notify);
 679         char event[] = "MEDIA_CHANGE=1";
 680         char *envp[] = { event, NULL };
 681
 682         /*
 683          * set enviroment vars to indicate which event this is for
 684          * so that user space will know to go check the media status.
 685          */
 686         kobject_uevent_env(&gd->dev.kobj, KOBJ_CHANGE, envp);
 687         put_device(gd->driverfs_dev);
 688 }
 689
 690 #if 0
 691 void genhd_media_change_notify(struct gendisk *disk)
 692 {
 693         get_device(disk->driverfs_dev);
 694         schedule_work(&disk->async_notify);
 695 }
 696 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 697 #endif  /*  0  */
 698
 699 struct find_block {
 700         const char *name;
 701         int part;
 702 };
 703
 704 static int match_id(struct device *dev, void *data)
 705 {
 706         struct find_block *find = data;
 707
 708         if (dev->type != &disk_type)
 709                 return 0;
 710         if (strcmp(dev->bus_id, find->name) == 0) {
 711                 struct gendisk *disk = dev_to_disk(dev);
 712                 if (find->part < disk->minors)
 713                         return 1;
 714         }
 715         return 0;
 716 }
 717
 718 dev_t blk_lookup_devt(const char *name, int part)
 719 {
 720         struct device *dev;
 721         dev_t devt = MKDEV(0, 0);
 722         struct find_block find;
 723
 724         find.name = name;
 725         find.part = part;
 726         dev = class_find_device(&block_class, NULL, &find, match_id);
 727         if (dev) {
 728                 put_device(dev);
 729                 devt = MKDEV(MAJOR(dev->devt),
 730                              MINOR(dev->devt) + part);
 731         }
 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);