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