fs/partitions/check.c

   1 /*
   2  *  fs/partitions/check.c
   3  *
   4  *  Code extracted from drivers/block/genhd.c
   5  *  Copyright (C) 1991-1998  Linus Torvalds
   6  *  Re-organised Feb 1998 Russell King
   7  *
   8  *  We now have independent partition support from the
   9  *  block drivers, which allows all the partition code to
  10  *  be grouped in one location, and it to be mostly self
  11  *  contained.
  12  *
  13  *  Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/fs.h>
  19 #include <linux/slab.h>
  20 #include <linux/kmod.h>
  21 #include <linux/ctype.h>
  22 #include <linux/genhd.h>
  23 #include <linux/blktrace_api.h>
  24
  25 #include "check.h"
  26
  27 #include "acorn.h"
  28 #include "amiga.h"
  29 #include "atari.h"
  30 #include "ldm.h"
  31 #include "mac.h"
  32 #include "msdos.h"
  33 #include "osf.h"
  34 #include "sgi.h"
  35 #include "sun.h"
  36 #include "ibm.h"
  37 #include "ultrix.h"
  38 #include "efi.h"
  39 #include "karma.h"
  40 #include "sysv68.h"
  41
  42 #ifdef CONFIG_BLK_DEV_MD
  43 extern void md_autodetect_dev(dev_t dev);
  44 #endif
  45
  46 int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
  47
  48 static int (*check_part[])(struct parsed_partitions *) = {
  49         /*
  50          * Probe partition formats with tables at disk address 0
  51          * that also have an ADFS boot block at 0xdc0.
  52          */
  53 #ifdef CONFIG_ACORN_PARTITION_ICS
  54         adfspart_check_ICS,
  55 #endif
  56 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
  57         adfspart_check_POWERTEC,
  58 #endif
  59 #ifdef CONFIG_ACORN_PARTITION_EESOX
  60         adfspart_check_EESOX,
  61 #endif
  62
  63         /*
  64          * Now move on to formats that only have partition info at
  65          * disk address 0xdc0.  Since these may also have stale
  66          * PC/BIOS partition tables, they need to come before
  67          * the msdos entry.
  68          */
  69 #ifdef CONFIG_ACORN_PARTITION_CUMANA
  70         adfspart_check_CUMANA,
  71 #endif
  72 #ifdef CONFIG_ACORN_PARTITION_ADFS
  73         adfspart_check_ADFS,
  74 #endif
  75
  76 #ifdef CONFIG_EFI_PARTITION
  77         efi_partition,          /* this must come before msdos */
  78 #endif
  79 #ifdef CONFIG_SGI_PARTITION
  80         sgi_partition,
  81 #endif
  82 #ifdef CONFIG_LDM_PARTITION
  83         ldm_partition,          /* this must come before msdos */
  84 #endif
  85 #ifdef CONFIG_MSDOS_PARTITION
  86         msdos_partition,
  87 #endif
  88 #ifdef CONFIG_OSF_PARTITION
  89         osf_partition,
  90 #endif
  91 #ifdef CONFIG_SUN_PARTITION
  92         sun_partition,
  93 #endif
  94 #ifdef CONFIG_AMIGA_PARTITION
  95         amiga_partition,
  96 #endif
  97 #ifdef CONFIG_ATARI_PARTITION
  98         atari_partition,
  99 #endif
 100 #ifdef CONFIG_MAC_PARTITION
 101         mac_partition,
 102 #endif
 103 #ifdef CONFIG_ULTRIX_PARTITION
 104         ultrix_partition,
 105 #endif
 106 #ifdef CONFIG_IBM_PARTITION
 107         ibm_partition,
 108 #endif
 109 #ifdef CONFIG_KARMA_PARTITION
 110         karma_partition,
 111 #endif
 112 #ifdef CONFIG_SYSV68_PARTITION
 113         sysv68_partition,
 114 #endif
 115         NULL
 116 };
 117
 118 /*
 119  * disk_name() is used by partition check code and the genhd driver.
 120  * It formats the devicename of the indicated disk into
 121  * the supplied buffer (of size at least 32), and returns
 122  * a pointer to that same buffer (for convenience).
 123  */
 124
 125 char *disk_name(struct gendisk *hd, int partno, char *buf)
 126 {
 127         if (!partno)
 128                 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
 129         else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
 130                 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
 131         else
 132                 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
 133
 134         return buf;
 135 }
 136
 137 const char *bdevname(struct block_device *bdev, char *buf)
 138 {
 139         return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
 140 }
 141
 142 EXPORT_SYMBOL(bdevname);
 143
 144 /*
 145  * There's very little reason to use this, you should really
 146  * have a struct block_device just about everywhere and use
 147  * bdevname() instead.
 148  */
 149 const char *__bdevname(dev_t dev, char *buffer)
 150 {
 151         scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
 152                                 MAJOR(dev), MINOR(dev));
 153         return buffer;
 154 }
 155
 156 EXPORT_SYMBOL(__bdevname);
 157
 158 static struct parsed_partitions *
 159 check_partition(struct gendisk *hd, struct block_device *bdev)
 160 {
 161         struct parsed_partitions *state;
 162         int i, res, err;
 163
 164         state = kzalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 165         if (!state)
 166                 return NULL;
 167         state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
 168         if (!state->pp_buf) {
 169                 kfree(state);
 170                 return NULL;
 171         }
 172         state->pp_buf[0] = '\0';
 173
 174         state->bdev = bdev;
 175         disk_name(hd, 0, state->name);
 176         snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
 177         if (isdigit(state->name[strlen(state->name)-1]))
 178                 sprintf(state->name, "p");
 179
 180         state->limit = disk_max_parts(hd);
 181         i = res = err = 0;
 182         while (!res && check_part[i]) {
 183                 memset(&state->parts, 0, sizeof(state->parts));
 184                 res = check_part[i++](state);
 185                 if (res < 0) {
 186                         /* We have hit an I/O error which we don't report now.
 187                         * But record it, and let the others do their job.
 188                         */
 189                         err = res;
 190                         res = 0;
 191                 }
 192
 193         }
 194         if (res > 0) {
 195                 printk(KERN_INFO "%s", state->pp_buf);
 196
 197                 free_page((unsigned long)state->pp_buf);
 198                 return state;
 199         }
 200         if (state->access_beyond_eod)
 201                 err = -ENOSPC;
 202         if (err)
 203         /* The partition is unrecognized. So report I/O errors if there were any */
 204                 res = err;
 205         if (!res)
 206                 strlcat(state->pp_buf, " unknown partition table\n", PAGE_SIZE);
 207         else if (warn_no_part)
 208                 strlcat(state->pp_buf, " unable to read partition table\n", PAGE_SIZE);
 209
 210         printk(KERN_INFO "%s", state->pp_buf);
 211
 212         free_page((unsigned long)state->pp_buf);
 213         kfree(state);
 214         return ERR_PTR(res);
 215 }
 216
 217 static ssize_t part_partition_show(struct device *dev,
 218                                    struct device_attribute *attr, char *buf)
 219 {
 220         struct hd_struct *p = dev_to_part(dev);
 221
 222         return sprintf(buf, "%d\n", p->partno);
 223 }
 224
 225 static ssize_t part_start_show(struct device *dev,
 226                                struct device_attribute *attr, char *buf)
 227 {
 228         struct hd_struct *p = dev_to_part(dev);
 229
 230         return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
 231 }
 232
 233 ssize_t part_size_show(struct device *dev,
 234                        struct device_attribute *attr, char *buf)
 235 {
 236         struct hd_struct *p = dev_to_part(dev);
 237         return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
 238 }
 239
 240 ssize_t part_ro_show(struct device *dev,
 241                        struct device_attribute *attr, char *buf)
 242 {
 243         struct hd_struct *p = dev_to_part(dev);
 244         return sprintf(buf, "%d\n", p->policy ? 1 : 0);
 245 }
 246
 247 ssize_t part_alignment_offset_show(struct device *dev,
 248                                    struct device_attribute *attr, char *buf)
 249 {
 250         struct hd_struct *p = dev_to_part(dev);
 251         return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset);
 252 }
 253
 254 ssize_t part_discard_alignment_show(struct device *dev,
 255                                    struct device_attribute *attr, char *buf)
 256 {
 257         struct hd_struct *p = dev_to_part(dev);
 258         return sprintf(buf, "%u\n", p->discard_alignment);
 259 }
 260
 261 ssize_t part_stat_show(struct device *dev,
 262                        struct device_attribute *attr, char *buf)
 263 {
 264         struct hd_struct *p = dev_to_part(dev);
 265         int cpu;
 266
 267         cpu = part_stat_lock();
 268         part_round_stats(cpu, p);
 269         part_stat_unlock();
 270         return sprintf(buf,
 271                 "%8lu %8lu %8llu %8u "
 272                 "%8lu %8lu %8llu %8u "
 273                 "%8u %8u %8u"
 274                 "\n",
 275                 part_stat_read(p, ios[READ]),
 276                 part_stat_read(p, merges[READ]),
 277                 (unsigned long long)part_stat_read(p, sectors[READ]),
 278                 jiffies_to_msecs(part_stat_read(p, ticks[READ])),
 279                 part_stat_read(p, ios[WRITE]),
 280                 part_stat_read(p, merges[WRITE]),
 281                 (unsigned long long)part_stat_read(p, sectors[WRITE]),
 282                 jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
 283                 part_in_flight(p),
 284                 jiffies_to_msecs(part_stat_read(p, io_ticks)),
 285                 jiffies_to_msecs(part_stat_read(p, time_in_queue)));
 286 }
 287
 288 ssize_t part_inflight_show(struct device *dev,
 289                         struct device_attribute *attr, char *buf)
 290 {
 291         struct hd_struct *p = dev_to_part(dev);
 292
 293         return sprintf(buf, "%8u %8u\n", p->in_flight[0], p->in_flight[1]);
 294 }
 295
 296 #ifdef CONFIG_FAIL_MAKE_REQUEST
 297 ssize_t part_fail_show(struct device *dev,
 298                        struct device_attribute *attr, char *buf)
 299 {
 300         struct hd_struct *p = dev_to_part(dev);
 301
 302         return sprintf(buf, "%d\n", p->make_it_fail);
 303 }
 304
 305 ssize_t part_fail_store(struct device *dev,
 306                         struct device_attribute *attr,
 307                         const char *buf, size_t count)
 308 {
 309         struct hd_struct *p = dev_to_part(dev);
 310         int i;
 311
 312         if (count > 0 && sscanf(buf, "%d", &i) > 0)
 313                 p->make_it_fail = (i == 0) ? 0 : 1;
 314
 315         return count;
 316 }
 317 #endif
 318
 319 static DEVICE_ATTR(partition, S_IRUGO, part_partition_show, NULL);
 320 static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
 321 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
 322 static DEVICE_ATTR(ro, S_IRUGO, part_ro_show, NULL);
 323 static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);
 324 static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show,
 325                    NULL);
 326 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
 327 static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
 328 #ifdef CONFIG_FAIL_MAKE_REQUEST
 329 static struct device_attribute dev_attr_fail =
 330         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
 331 #endif
 332
 333 static struct attribute *part_attrs[] = {
 334         &dev_attr_partition.attr,
 335         &dev_attr_start.attr,
 336         &dev_attr_size.attr,
 337         &dev_attr_ro.attr,
 338         &dev_attr_alignment_offset.attr,
 339         &dev_attr_discard_alignment.attr,
 340         &dev_attr_stat.attr,
 341         &dev_attr_inflight.attr,
 342 #ifdef CONFIG_FAIL_MAKE_REQUEST
 343         &dev_attr_fail.attr,
 344 #endif
 345         NULL
 346 };
 347
 348 static struct attribute_group part_attr_group = {
 349         .attrs = part_attrs,
 350 };
 351
 352 static const struct attribute_group *part_attr_groups[] = {
 353         &part_attr_group,
 354 #ifdef CONFIG_BLK_DEV_IO_TRACE
 355         &blk_trace_attr_group,
 356 #endif
 357         NULL
 358 };
 359
 360 static void part_release(struct device *dev)
 361 {
 362         struct hd_struct *p = dev_to_part(dev);
 363         free_part_stats(p);
 364         free_part_info(p);
 365         kfree(p);
 366 }
 367
 368 struct device_type part_type = {
 369         .name           = "partition",
 370         .groups         = part_attr_groups,
 371         .release        = part_release,
 372 };
 373
 374 static void delete_partition_rcu_cb(struct rcu_head *head)
 375 {
 376         struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
 377
 378         part->start_sect = 0;
 379         part->nr_sects = 0;
 380         part_stat_set_all(part, 0);
 381         put_device(part_to_dev(part));
 382 }
 383
 384 void __delete_partition(struct kref *ref)
 385 {
 386         struct hd_struct *part = container_of(ref, struct hd_struct, ref);
 387
 388         call_rcu(&part->rcu_head, delete_partition_rcu_cb);
 389 }
 390
 391 void delete_partition(struct gendisk *disk, int partno)
 392 {
 393         struct disk_part_tbl *ptbl = disk->part_tbl;
 394         struct hd_struct *part;
 395
 396         if (partno >= ptbl->len)
 397                 return;
 398
 399         part = ptbl->part[partno];
 400         if (!part)
 401                 return;
 402
 403         blk_free_devt(part_devt(part));
 404         rcu_assign_pointer(ptbl->part[partno], NULL);
 405         rcu_assign_pointer(ptbl->last_lookup, NULL);
 406         kobject_put(part->holder_dir);
 407         device_del(part_to_dev(part));
 408
 409         kref_put(&part->ref, __delete_partition);
 410 }
 411
 412 static ssize_t whole_disk_show(struct device *dev,
 413                                struct device_attribute *attr, char *buf)
 414 {
 415         return 0;
 416 }
 417 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
 418                    whole_disk_show, NULL);
 419
 420 struct hd_struct *add_partition(struct gendisk *disk, int partno,
 421                                 sector_t start, sector_t len, int flags,
 422                                 struct partition_meta_info *info)
 423 {
 424         struct hd_struct *p;
 425         dev_t devt = MKDEV(0, 0);
 426         struct device *ddev = disk_to_dev(disk);
 427         struct device *pdev;
 428         struct disk_part_tbl *ptbl;
 429         const char *dname;
 430         int err;
 431
 432         err = disk_expand_part_tbl(disk, partno);
 433         if (err)
 434                 return ERR_PTR(err);
 435         ptbl = disk->part_tbl;
 436
 437         if (ptbl->part[partno])
 438                 return ERR_PTR(-EBUSY);
 439
 440         p = kzalloc(sizeof(*p), GFP_KERNEL);
 441         if (!p)
 442                 return ERR_PTR(-EBUSY);
 443
 444         if (!init_part_stats(p)) {
 445                 err = -ENOMEM;
 446                 goto out_free;
 447         }
 448         pdev = part_to_dev(p);
 449
 450         p->start_sect = start;
 451         p->alignment_offset =
 452                 queue_limit_alignment_offset(&disk->queue->limits, start);
 453         p->discard_alignment =
 454                 queue_limit_discard_alignment(&disk->queue->limits, start);
 455         p->nr_sects = len;
 456         p->partno = partno;
 457         p->policy = get_disk_ro(disk);
 458
 459         if (info) {
 460                 struct partition_meta_info *pinfo = alloc_part_info(disk);
 461                 if (!pinfo)
 462                         goto out_free_stats;
 463                 memcpy(pinfo, info, sizeof(*info));
 464                 p->info = pinfo;
 465         }
 466
 467         dname = dev_name(ddev);
 468         if (isdigit(dname[strlen(dname) - 1]))
 469                 dev_set_name(pdev, "%sp%d", dname, partno);
 470         else
 471                 dev_set_name(pdev, "%s%d", dname, partno);
 472
 473         device_initialize(pdev);
 474         pdev->class = &block_class;
 475         pdev->type = &part_type;
 476         pdev->parent = ddev;
 477
 478         err = blk_alloc_devt(p, &devt);
 479         if (err)
 480                 goto out_free_info;
 481         pdev->devt = devt;
 482
 483         /* delay uevent until 'holders' subdir is created */
 484         dev_set_uevent_suppress(pdev, 1);
 485         err = device_add(pdev);
 486         if (err)
 487                 goto out_put;
 488
 489         err = -ENOMEM;
 490         p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
 491         if (!p->holder_dir)
 492                 goto out_del;
 493
 494         dev_set_uevent_suppress(pdev, 0);
 495         if (flags & ADDPART_FLAG_WHOLEDISK) {
 496                 err = device_create_file(pdev, &dev_attr_whole_disk);
 497                 if (err)
 498                         goto out_del;
 499         }
 500
 501         /* everything is up and running, commence */
 502         rcu_assign_pointer(ptbl->part[partno], p);
 503
 504         /* suppress uevent if the disk supresses it */
 505         if (!dev_get_uevent_suppress(ddev))
 506                 kobject_uevent(&pdev->kobj, KOBJ_ADD);
 507
 508         kref_init(&p->ref);
 509         return p;
 510
 511 out_free_info:
 512         free_part_info(p);
 513 out_free_stats:
 514         free_part_stats(p);
 515 out_free:
 516         kfree(p);
 517         return ERR_PTR(err);
 518 out_del:
 519         kobject_put(p->holder_dir);
 520         device_del(pdev);
 521 out_put:
 522         put_device(pdev);
 523         blk_free_devt(devt);
 524         return ERR_PTR(err);
 525 }
 526
 527 /* Not exported, helper to add_disk(). */
 528 void register_disk(struct gendisk *disk)
 529 {
 530         struct device *ddev = disk_to_dev(disk);
 531         struct block_device *bdev;
 532         struct disk_part_iter piter;
 533         struct hd_struct *part;
 534         int err;
 535
 536         ddev->parent = disk->driverfs_dev;
 537
 538         dev_set_name(ddev, disk->disk_name);
 539
 540         /* delay uevents, until we scanned partition table */
 541         dev_set_uevent_suppress(ddev, 1);
 542
 543         if (device_add(ddev))
 544                 return;
 545         if (!sysfs_deprecated) {
 546                 err = sysfs_create_link(block_depr, &ddev->kobj,
 547                                         kobject_name(&ddev->kobj));
 548                 if (err) {
 549                         device_del(ddev);
 550                         return;
 551                 }
 552         }
 553         disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
 554         disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
 555
 556         /* No minors to use for partitions */
 557         if (!disk_partitionable(disk))
 558                 goto exit;
 559
 560         /* No such device (e.g., media were just removed) */
 561         if (!get_capacity(disk))
 562                 goto exit;
 563
 564         bdev = bdget_disk(disk, 0);
 565         if (!bdev)
 566                 goto exit;
 567
 568         bdev->bd_invalidated = 1;
 569         err = blkdev_get(bdev, FMODE_READ, NULL);
 570         if (err < 0)
 571                 goto exit;
 572         blkdev_put(bdev, FMODE_READ);
 573
 574 exit:
 575         /* announce disk after possible partitions are created */
 576         dev_set_uevent_suppress(ddev, 0);
 577         kobject_uevent(&ddev->kobj, KOBJ_ADD);
 578
 579         /* announce possible partitions */
 580         disk_part_iter_init(&piter, disk, 0);
 581         while ((part = disk_part_iter_next(&piter)))
 582                 kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
 583         disk_part_iter_exit(&piter);
 584 }
 585
 586 static bool disk_unlock_native_capacity(struct gendisk *disk)
 587 {
 588         const struct block_device_operations *bdops = disk->fops;
 589
 590         if (bdops->unlock_native_capacity &&
 591             !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
 592                 printk(KERN_CONT "enabling native capacity\n");
 593                 bdops->unlock_native_capacity(disk);
 594                 disk->flags |= GENHD_FL_NATIVE_CAPACITY;
 595                 return true;
 596         } else {
 597                 printk(KERN_CONT "truncated\n");
 598                 return false;
 599         }
 600 }
 601
 602 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 603 {
 604         struct parsed_partitions *state = NULL;
 605         struct disk_part_iter piter;
 606         struct hd_struct *part;
 607         int p, highest, res;
 608 rescan:
 609         if (state && !IS_ERR(state)) {
 610                 kfree(state);
 611                 state = NULL;
 612         }
 613
 614         if (bdev->bd_part_count)
 615                 return -EBUSY;
 616         res = invalidate_partition(disk, 0);
 617         if (res)
 618                 return res;
 619
 620         disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
 621         while ((part = disk_part_iter_next(&piter)))
 622                 delete_partition(disk, part->partno);
 623         disk_part_iter_exit(&piter);
 624
 625         if (disk->fops->revalidate_disk)
 626                 disk->fops->revalidate_disk(disk);
 627         check_disk_size_change(disk, bdev);
 628         bdev->bd_invalidated = 0;
 629         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 630                 return 0;
 631         if (IS_ERR(state)) {
 632                 /*
 633                  * I/O error reading the partition table.  If any
 634                  * partition code tried to read beyond EOD, retry
 635                  * after unlocking native capacity.
 636                  */
 637                 if (PTR_ERR(state) == -ENOSPC) {
 638                         printk(KERN_WARNING "%s: partition table beyond EOD, ",
 639                                disk->disk_name);
 640                         if (disk_unlock_native_capacity(disk))
 641                                 goto rescan;
 642                 }
 643                 return -EIO;
 644         }
 645         /*
 646          * If any partition code tried to read beyond EOD, try
 647          * unlocking native capacity even if partition table is
 648          * sucessfully read as we could be missing some partitions.
 649          */
 650         if (state->access_beyond_eod) {
 651                 printk(KERN_WARNING
 652                        "%s: partition table partially beyond EOD, ",
 653                        disk->disk_name);
 654                 if (disk_unlock_native_capacity(disk))
 655                         goto rescan;
 656         }
 657
 658         /* tell userspace that the media / partition table may have changed */
 659         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 660
 661         /* Detect the highest partition number and preallocate
 662          * disk->part_tbl.  This is an optimization and not strictly
 663          * necessary.
 664          */
 665         for (p = 1, highest = 0; p < state->limit; p++)
 666                 if (state->parts[p].size)
 667                         highest = p;
 668
 669         disk_expand_part_tbl(disk, highest);
 670
 671         /* add partitions */
 672         for (p = 1; p < state->limit; p++) {
 673                 sector_t size, from;
 674                 struct partition_meta_info *info = NULL;
 675
 676                 size = state->parts[p].size;
 677                 if (!size)
 678                         continue;
 679
 680                 from = state->parts[p].from;
 681                 if (from >= get_capacity(disk)) {
 682                         printk(KERN_WARNING
 683                                "%s: p%d start %llu is beyond EOD, ",
 684                                disk->disk_name, p, (unsigned long long) from);
 685                         if (disk_unlock_native_capacity(disk))
 686                                 goto rescan;
 687                         continue;
 688                 }
 689
 690                 if (from + size > get_capacity(disk)) {
 691                         printk(KERN_WARNING
 692                                "%s: p%d size %llu extends beyond EOD, ",
 693                                disk->disk_name, p, (unsigned long long) size);
 694
 695                         if (disk_unlock_native_capacity(disk)) {
 696                                 /* free state and restart */
 697                                 goto rescan;
 698                         } else {
 699                                 /*
 700                                  * we can not ignore partitions of broken tables
 701                                  * created by for example camera firmware, but
 702                                  * we limit them to the end of the disk to avoid
 703                                  * creating invalid block devices
 704                                  */
 705                                 size = get_capacity(disk) - from;
 706                         }
 707                 }
 708
 709                 if (state->parts[p].has_info)
 710                         info = &state->parts[p].info;
 711                 part = add_partition(disk, p, from, size,
 712                                      state->parts[p].flags,
 713                                      &state->parts[p].info);
 714                 if (IS_ERR(part)) {
 715                         printk(KERN_ERR " %s: p%d could not be added: %ld\n",
 716                                disk->disk_name, p, -PTR_ERR(part));
 717                         continue;
 718                 }
 719 #ifdef CONFIG_BLK_DEV_MD
 720                 if (state->parts[p].flags & ADDPART_FLAG_RAID)
 721                         md_autodetect_dev(part_to_dev(part)->devt);
 722 #endif
 723         }
 724         kfree(state);
 725         return 0;
 726 }
 727
 728 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 729 {
 730         struct address_space *mapping = bdev->bd_inode->i_mapping;
 731         struct page *page;
 732
 733         page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 734                                  NULL);
 735         if (!IS_ERR(page)) {
 736                 if (PageError(page))
 737                         goto fail;
 738                 p->v = page;
 739                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 740 fail:
 741                 page_cache_release(page);
 742         }
 743         p->v = NULL;
 744         return NULL;
 745 }
 746
 747 EXPORT_SYMBOL(read_dev_sector);
 748
 749 void del_gendisk(struct gendisk *disk)
 750 {
 751         struct disk_part_iter piter;
 752         struct hd_struct *part;
 753
 754         /* invalidate stuff */
 755         disk_part_iter_init(&piter, disk,
 756                              DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
 757         while ((part = disk_part_iter_next(&piter))) {
 758                 invalidate_partition(disk, part->partno);
 759                 delete_partition(disk, part->partno);
 760         }
 761         disk_part_iter_exit(&piter);
 762
 763         invalidate_partition(disk, 0);
 764         blk_free_devt(disk_to_dev(disk)->devt);
 765         set_capacity(disk, 0);
 766         disk->flags &= ~GENHD_FL_UP;
 767         unlink_gendisk(disk);
 768         part_stat_set_all(&disk->part0, 0);
 769         disk->part0.stamp = 0;
 770
 771         kobject_put(disk->part0.holder_dir);
 772         kobject_put(disk->slave_dir);
 773         disk->driverfs_dev = NULL;
 774         if (!sysfs_deprecated)
 775                 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
 776         device_del(disk_to_dev(disk));
 777 }