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/kmod.h>
  20 #include <linux/ctype.h>
  21 #include <linux/genhd.h>
  22
  23 #include "check.h"
  24
  25 #include "acorn.h"
  26 #include "amiga.h"
  27 #include "atari.h"
  28 #include "ldm.h"
  29 #include "mac.h"
  30 #include "msdos.h"
  31 #include "osf.h"
  32 #include "sgi.h"
  33 #include "sun.h"
  34 #include "ibm.h"
  35 #include "ultrix.h"
  36 #include "efi.h"
  37 #include "karma.h"
  38 #include "sysv68.h"
  39
  40 #ifdef CONFIG_BLK_DEV_MD
  41 extern void md_autodetect_dev(dev_t dev);
  42 #endif
  43
  44 int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
  45
  46 static int (*check_part[])(struct parsed_partitions *, struct block_device *) = {
  47         /*
  48          * Probe partition formats with tables at disk address 0
  49          * that also have an ADFS boot block at 0xdc0.
  50          */
  51 #ifdef CONFIG_ACORN_PARTITION_ICS
  52         adfspart_check_ICS,
  53 #endif
  54 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
  55         adfspart_check_POWERTEC,
  56 #endif
  57 #ifdef CONFIG_ACORN_PARTITION_EESOX
  58         adfspart_check_EESOX,
  59 #endif
  60
  61         /*
  62          * Now move on to formats that only have partition info at
  63          * disk address 0xdc0.  Since these may also have stale
  64          * PC/BIOS partition tables, they need to come before
  65          * the msdos entry.
  66          */
  67 #ifdef CONFIG_ACORN_PARTITION_CUMANA
  68         adfspart_check_CUMANA,
  69 #endif
  70 #ifdef CONFIG_ACORN_PARTITION_ADFS
  71         adfspart_check_ADFS,
  72 #endif
  73
  74 #ifdef CONFIG_EFI_PARTITION
  75         efi_partition,          /* this must come before msdos */
  76 #endif
  77 #ifdef CONFIG_SGI_PARTITION
  78         sgi_partition,
  79 #endif
  80 #ifdef CONFIG_LDM_PARTITION
  81         ldm_partition,          /* this must come before msdos */
  82 #endif
  83 #ifdef CONFIG_MSDOS_PARTITION
  84         msdos_partition,
  85 #endif
  86 #ifdef CONFIG_OSF_PARTITION
  87         osf_partition,
  88 #endif
  89 #ifdef CONFIG_SUN_PARTITION
  90         sun_partition,
  91 #endif
  92 #ifdef CONFIG_AMIGA_PARTITION
  93         amiga_partition,
  94 #endif
  95 #ifdef CONFIG_ATARI_PARTITION
  96         atari_partition,
  97 #endif
  98 #ifdef CONFIG_MAC_PARTITION
  99         mac_partition,
 100 #endif
 101 #ifdef CONFIG_ULTRIX_PARTITION
 102         ultrix_partition,
 103 #endif
 104 #ifdef CONFIG_IBM_PARTITION
 105         ibm_partition,
 106 #endif
 107 #ifdef CONFIG_KARMA_PARTITION
 108         karma_partition,
 109 #endif
 110 #ifdef CONFIG_SYSV68_PARTITION
 111         sysv68_partition,
 112 #endif
 113         NULL
 114 };
 115
 116 /*
 117  * disk_name() is used by partition check code and the genhd driver.
 118  * It formats the devicename of the indicated disk into
 119  * the supplied buffer (of size at least 32), and returns
 120  * a pointer to that same buffer (for convenience).
 121  */
 122
 123 char *disk_name(struct gendisk *hd, int partno, char *buf)
 124 {
 125         if (!partno)
 126                 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
 127         else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
 128                 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
 129         else
 130                 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
 131
 132         return buf;
 133 }
 134
 135 const char *bdevname(struct block_device *bdev, char *buf)
 136 {
 137         return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
 138 }
 139
 140 EXPORT_SYMBOL(bdevname);
 141
 142 /*
 143  * There's very little reason to use this, you should really
 144  * have a struct block_device just about everywhere and use
 145  * bdevname() instead.
 146  */
 147 const char *__bdevname(dev_t dev, char *buffer)
 148 {
 149         scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
 150                                 MAJOR(dev), MINOR(dev));
 151         return buffer;
 152 }
 153
 154 EXPORT_SYMBOL(__bdevname);
 155
 156 static struct parsed_partitions *
 157 check_partition(struct gendisk *hd, struct block_device *bdev)
 158 {
 159         struct parsed_partitions *state;
 160         int i, res, err;
 161
 162         state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 163         if (!state)
 164                 return NULL;
 165
 166         disk_name(hd, 0, state->name);
 167         printk(KERN_INFO " %s:", state->name);
 168         if (isdigit(state->name[strlen(state->name)-1]))
 169                 sprintf(state->name, "p");
 170
 171         state->limit = disk_max_parts(hd);
 172         i = res = err = 0;
 173         while (!res && check_part[i]) {
 174                 memset(&state->parts, 0, sizeof(state->parts));
 175                 res = check_part[i++](state, bdev);
 176                 if (res < 0) {
 177                         /* We have hit an I/O error which we don't report now.
 178                         * But record it, and let the others do their job.
 179                         */
 180                         err = res;
 181                         res = 0;
 182                 }
 183
 184         }
 185         if (res > 0)
 186                 return state;
 187         if (err)
 188         /* The partition is unrecognized. So report I/O errors if there were any */
 189                 res = err;
 190         if (!res)
 191                 printk(" unknown partition table\n");
 192         else if (warn_no_part)
 193                 printk(" unable to read partition table\n");
 194         kfree(state);
 195         return ERR_PTR(res);
 196 }
 197
 198 static ssize_t part_start_show(struct device *dev,
 199                                struct device_attribute *attr, char *buf)
 200 {
 201         struct hd_struct *p = dev_to_part(dev);
 202
 203         return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
 204 }
 205
 206 ssize_t part_size_show(struct device *dev,
 207                        struct device_attribute *attr, char *buf)
 208 {
 209         struct hd_struct *p = dev_to_part(dev);
 210         return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
 211 }
 212
 213 ssize_t part_stat_show(struct device *dev,
 214                        struct device_attribute *attr, char *buf)
 215 {
 216         struct hd_struct *p = dev_to_part(dev);
 217         int cpu;
 218
 219         cpu = part_stat_lock();
 220         part_round_stats(cpu, p);
 221         part_stat_unlock();
 222         return sprintf(buf,
 223                 "%8lu %8lu %8llu %8u "
 224                 "%8lu %8lu %8llu %8u "
 225                 "%8u %8u %8u"
 226                 "\n",
 227                 part_stat_read(p, ios[READ]),
 228                 part_stat_read(p, merges[READ]),
 229                 (unsigned long long)part_stat_read(p, sectors[READ]),
 230                 jiffies_to_msecs(part_stat_read(p, ticks[READ])),
 231                 part_stat_read(p, ios[WRITE]),
 232                 part_stat_read(p, merges[WRITE]),
 233                 (unsigned long long)part_stat_read(p, sectors[WRITE]),
 234                 jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
 235                 p->in_flight,
 236                 jiffies_to_msecs(part_stat_read(p, io_ticks)),
 237                 jiffies_to_msecs(part_stat_read(p, time_in_queue)));
 238 }
 239
 240 #ifdef CONFIG_FAIL_MAKE_REQUEST
 241 ssize_t part_fail_show(struct device *dev,
 242                        struct device_attribute *attr, char *buf)
 243 {
 244         struct hd_struct *p = dev_to_part(dev);
 245
 246         return sprintf(buf, "%d\n", p->make_it_fail);
 247 }
 248
 249 ssize_t part_fail_store(struct device *dev,
 250                         struct device_attribute *attr,
 251                         const char *buf, size_t count)
 252 {
 253         struct hd_struct *p = dev_to_part(dev);
 254         int i;
 255
 256         if (count > 0 && sscanf(buf, "%d", &i) > 0)
 257                 p->make_it_fail = (i == 0) ? 0 : 1;
 258
 259         return count;
 260 }
 261 #endif
 262
 263 static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
 264 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
 265 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
 266 #ifdef CONFIG_FAIL_MAKE_REQUEST
 267 static struct device_attribute dev_attr_fail =
 268         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
 269 #endif
 270
 271 static struct attribute *part_attrs[] = {
 272         &dev_attr_start.attr,
 273         &dev_attr_size.attr,
 274         &dev_attr_stat.attr,
 275 #ifdef CONFIG_FAIL_MAKE_REQUEST
 276         &dev_attr_fail.attr,
 277 #endif
 278         NULL
 279 };
 280
 281 static struct attribute_group part_attr_group = {
 282         .attrs = part_attrs,
 283 };
 284
 285 static struct attribute_group *part_attr_groups[] = {
 286         &part_attr_group,
 287         NULL
 288 };
 289
 290 static void part_release(struct device *dev)
 291 {
 292         struct hd_struct *p = dev_to_part(dev);
 293         free_part_stats(p);
 294         kfree(p);
 295 }
 296
 297 struct device_type part_type = {
 298         .name           = "partition",
 299         .groups         = part_attr_groups,
 300         .release        = part_release,
 301 };
 302
 303 static void delete_partition_rcu_cb(struct rcu_head *head)
 304 {
 305         struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
 306
 307         part->start_sect = 0;
 308         part->nr_sects = 0;
 309         part_stat_set_all(part, 0);
 310         put_device(part_to_dev(part));
 311 }
 312
 313 void delete_partition(struct gendisk *disk, int partno)
 314 {
 315         struct disk_part_tbl *ptbl = disk->part_tbl;
 316         struct hd_struct *part;
 317
 318         if (partno >= ptbl->len)
 319                 return;
 320
 321         part = ptbl->part[partno];
 322         if (!part)
 323                 return;
 324
 325         blk_free_devt(part_devt(part));
 326         rcu_assign_pointer(ptbl->part[partno], NULL);
 327         kobject_put(part->holder_dir);
 328         device_del(part_to_dev(part));
 329
 330         call_rcu(&part->rcu_head, delete_partition_rcu_cb);
 331 }
 332
 333 static ssize_t whole_disk_show(struct device *dev,
 334                                struct device_attribute *attr, char *buf)
 335 {
 336         return 0;
 337 }
 338 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
 339                    whole_disk_show, NULL);
 340
 341 int add_partition(struct gendisk *disk, int partno,
 342                   sector_t start, sector_t len, int flags)
 343 {
 344         struct hd_struct *p;
 345         dev_t devt = MKDEV(0, 0);
 346         struct device *ddev = disk_to_dev(disk);
 347         struct device *pdev;
 348         struct disk_part_tbl *ptbl;
 349         const char *dname;
 350         int err;
 351
 352         err = disk_expand_part_tbl(disk, partno);
 353         if (err)
 354                 return err;
 355         ptbl = disk->part_tbl;
 356
 357         if (ptbl->part[partno])
 358                 return -EBUSY;
 359
 360         p = kzalloc(sizeof(*p), GFP_KERNEL);
 361         if (!p)
 362                 return -ENOMEM;
 363
 364         if (!init_part_stats(p)) {
 365                 err = -ENOMEM;
 366                 goto out_free;
 367         }
 368         pdev = part_to_dev(p);
 369
 370         p->start_sect = start;
 371         p->nr_sects = len;
 372         p->partno = partno;
 373         p->policy = get_disk_ro(disk);
 374
 375         dname = dev_name(ddev);
 376         if (isdigit(dname[strlen(dname) - 1]))
 377                 snprintf(pdev->bus_id, BUS_ID_SIZE, "%sp%d", dname, partno);
 378         else
 379                 snprintf(pdev->bus_id, BUS_ID_SIZE, "%s%d", dname, partno);
 380
 381         device_initialize(pdev);
 382         pdev->class = &block_class;
 383         pdev->type = &part_type;
 384         pdev->parent = ddev;
 385
 386         err = blk_alloc_devt(p, &devt);
 387         if (err)
 388                 goto out_free;
 389         pdev->devt = devt;
 390
 391         /* delay uevent until 'holders' subdir is created */
 392         pdev->uevent_suppress = 1;
 393         err = device_add(pdev);
 394         if (err)
 395                 goto out_put;
 396
 397         err = -ENOMEM;
 398         p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
 399         if (!p->holder_dir)
 400                 goto out_del;
 401
 402         pdev->uevent_suppress = 0;
 403         if (flags & ADDPART_FLAG_WHOLEDISK) {
 404                 err = device_create_file(pdev, &dev_attr_whole_disk);
 405                 if (err)
 406                         goto out_del;
 407         }
 408
 409         /* everything is up and running, commence */
 410         INIT_RCU_HEAD(&p->rcu_head);
 411         rcu_assign_pointer(ptbl->part[partno], p);
 412
 413         /* suppress uevent if the disk supresses it */
 414         if (!ddev->uevent_suppress)
 415                 kobject_uevent(&pdev->kobj, KOBJ_ADD);
 416
 417         return 0;
 418
 419 out_free:
 420         kfree(p);
 421         return err;
 422 out_del:
 423         kobject_put(p->holder_dir);
 424         device_del(pdev);
 425 out_put:
 426         put_device(pdev);
 427         blk_free_devt(devt);
 428         return err;
 429 }
 430
 431 /* Not exported, helper to add_disk(). */
 432 void register_disk(struct gendisk *disk)
 433 {
 434         struct device *ddev = disk_to_dev(disk);
 435         struct block_device *bdev;
 436         struct disk_part_iter piter;
 437         struct hd_struct *part;
 438         char *s;
 439         int err;
 440
 441         ddev->parent = disk->driverfs_dev;
 442
 443         strlcpy(ddev->bus_id, disk->disk_name, BUS_ID_SIZE);
 444         /* ewww... some of these buggers have / in the name... */
 445         s = strchr(ddev->bus_id, '/');
 446         if (s)
 447                 *s = '!';
 448
 449         /* delay uevents, until we scanned partition table */
 450         ddev->uevent_suppress = 1;
 451
 452         if (device_add(ddev))
 453                 return;
 454 #ifndef CONFIG_SYSFS_DEPRECATED
 455         err = sysfs_create_link(block_depr, &ddev->kobj,
 456                                 kobject_name(&ddev->kobj));
 457         if (err) {
 458                 device_del(ddev);
 459                 return;
 460         }
 461 #endif
 462         disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
 463         disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
 464
 465         /* No minors to use for partitions */
 466         if (!disk_partitionable(disk))
 467                 goto exit;
 468
 469         /* No such device (e.g., media were just removed) */
 470         if (!get_capacity(disk))
 471                 goto exit;
 472
 473         bdev = bdget_disk(disk, 0);
 474         if (!bdev)
 475                 goto exit;
 476
 477         bdev->bd_invalidated = 1;
 478         err = blkdev_get(bdev, FMODE_READ, 0);
 479         if (err < 0)
 480                 goto exit;
 481         blkdev_put(bdev);
 482
 483 exit:
 484         /* announce disk after possible partitions are created */
 485         ddev->uevent_suppress = 0;
 486         kobject_uevent(&ddev->kobj, KOBJ_ADD);
 487
 488         /* announce possible partitions */
 489         disk_part_iter_init(&piter, disk, 0);
 490         while ((part = disk_part_iter_next(&piter)))
 491                 kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
 492         disk_part_iter_exit(&piter);
 493 }
 494
 495 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 496 {
 497         struct disk_part_iter piter;
 498         struct hd_struct *part;
 499         struct parsed_partitions *state;
 500         int p, highest, res;
 501
 502         if (bdev->bd_part_count)
 503                 return -EBUSY;
 504         res = invalidate_partition(disk, 0);
 505         if (res)
 506                 return res;
 507
 508         disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
 509         while ((part = disk_part_iter_next(&piter)))
 510                 delete_partition(disk, part->partno);
 511         disk_part_iter_exit(&piter);
 512
 513         if (disk->fops->revalidate_disk)
 514                 disk->fops->revalidate_disk(disk);
 515         check_disk_size_change(disk, bdev);
 516         bdev->bd_invalidated = 0;
 517         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 518                 return 0;
 519         if (IS_ERR(state))      /* I/O error reading the partition table */
 520                 return -EIO;
 521
 522         /* tell userspace that the media / partition table may have changed */
 523         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 524
 525         /* Detect the highest partition number and preallocate
 526          * disk->part_tbl.  This is an optimization and not strictly
 527          * necessary.
 528          */
 529         for (p = 1, highest = 0; p < state->limit; p++)
 530                 if (state->parts[p].size)
 531                         highest = p;
 532
 533         disk_expand_part_tbl(disk, highest);
 534
 535         /* add partitions */
 536         for (p = 1; p < state->limit; p++) {
 537                 sector_t size = state->parts[p].size;
 538                 sector_t from = state->parts[p].from;
 539                 if (!size)
 540                         continue;
 541                 if (from >= get_capacity(disk)) {
 542                         printk(KERN_WARNING
 543                                "%s: p%d ignored, start %llu is behind the end of the disk\n",
 544                                disk->disk_name, p, (unsigned long long) from);
 545                         continue;
 546                 }
 547                 if (from + size > get_capacity(disk)) {
 548                         /*
 549                          * we can not ignore partitions of broken tables
 550                          * created by for example camera firmware, but we
 551                          * limit them to the end of the disk to avoid
 552                          * creating invalid block devices
 553                          */
 554                         printk(KERN_WARNING
 555                                "%s: p%d size %llu limited to end of disk\n",
 556                                disk->disk_name, p, (unsigned long long) size);
 557                         size = get_capacity(disk) - from;
 558                 }
 559                 res = add_partition(disk, p, from, size, state->parts[p].flags);
 560                 if (res) {
 561                         printk(KERN_ERR " %s: p%d could not be added: %d\n",
 562                                 disk->disk_name, p, -res);
 563                         continue;
 564                 }
 565 #ifdef CONFIG_BLK_DEV_MD
 566                 if (state->parts[p].flags & ADDPART_FLAG_RAID)
 567                         md_autodetect_dev(bdev->bd_dev+p);
 568 #endif
 569         }
 570         kfree(state);
 571         return 0;
 572 }
 573
 574 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 575 {
 576         struct address_space *mapping = bdev->bd_inode->i_mapping;
 577         struct page *page;
 578
 579         page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 580                                  NULL);
 581         if (!IS_ERR(page)) {
 582                 if (PageError(page))
 583                         goto fail;
 584                 p->v = page;
 585                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 586 fail:
 587                 page_cache_release(page);
 588         }
 589         p->v = NULL;
 590         return NULL;
 591 }
 592
 593 EXPORT_SYMBOL(read_dev_sector);
 594
 595 void del_gendisk(struct gendisk *disk)
 596 {
 597         struct disk_part_iter piter;
 598         struct hd_struct *part;
 599
 600         /* invalidate stuff */
 601         disk_part_iter_init(&piter, disk,
 602                              DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
 603         while ((part = disk_part_iter_next(&piter))) {
 604                 invalidate_partition(disk, part->partno);
 605                 delete_partition(disk, part->partno);
 606         }
 607         disk_part_iter_exit(&piter);
 608
 609         invalidate_partition(disk, 0);
 610         blk_free_devt(disk_to_dev(disk)->devt);
 611         set_capacity(disk, 0);
 612         disk->flags &= ~GENHD_FL_UP;
 613         unlink_gendisk(disk);
 614         part_stat_set_all(&disk->part0, 0);
 615         disk->part0.stamp = 0;
 616
 617         kobject_put(disk->part0.holder_dir);
 618         kobject_put(disk->slave_dir);
 619         disk->driverfs_dev = NULL;
 620 #ifndef CONFIG_SYSFS_DEPRECATED
 621         sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
 622 #endif
 623         device_del(disk_to_dev(disk));
 624 }