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