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;
 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 = 0;
 169         while (!res && check_part[i]) {
 170                 memset(&state->parts, 0, sizeof(state->parts));
 171                 res = check_part[i++](state, bdev);
 172         }
 173         if (res > 0)
 174                 return state;
 175         if (!res)
 176                 printk(" unknown partition table\n");
 177         else if (warn_no_part)
 178                 printk(" unable to read partition table\n");
 179         kfree(state);
 180         return NULL;
 181 }
 182
 183 /*
 184  * sysfs bindings for partitions
 185  */
 186
 187 struct part_attribute {
 188         struct attribute attr;
 189         ssize_t (*show)(struct hd_struct *,char *);
 190         ssize_t (*store)(struct hd_struct *,const char *, size_t);
 191 };
 192
 193 static ssize_t
 194 part_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
 195 {
 196         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 197         struct part_attribute * part_attr = container_of(attr,struct part_attribute,attr);
 198         ssize_t ret = 0;
 199         if (part_attr->show)
 200                 ret = part_attr->show(p, page);
 201         return ret;
 202 }
 203 static ssize_t
 204 part_attr_store(struct kobject * kobj, struct attribute * attr,
 205                 const char *page, size_t count)
 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
 211         if (part_attr->store)
 212                 ret = part_attr->store(p, page, count);
 213         return ret;
 214 }
 215
 216 static struct sysfs_ops part_sysfs_ops = {
 217         .show   =       part_attr_show,
 218         .store  =       part_attr_store,
 219 };
 220
 221 static ssize_t part_uevent_store(struct hd_struct * p,
 222                                  const char *page, size_t count)
 223 {
 224         kobject_uevent(&p->kobj, KOBJ_ADD);
 225         return count;
 226 }
 227 static ssize_t part_dev_read(struct hd_struct * p, char *page)
 228 {
 229         struct gendisk *disk = container_of(p->kobj.parent,struct gendisk,kobj);
 230         dev_t dev = MKDEV(disk->major, disk->first_minor + p->partno);
 231         return print_dev_t(page, dev);
 232 }
 233 static ssize_t part_start_read(struct hd_struct * p, char *page)
 234 {
 235         return sprintf(page, "%llu\n",(unsigned long long)p->start_sect);
 236 }
 237 static ssize_t part_size_read(struct hd_struct * p, char *page)
 238 {
 239         return sprintf(page, "%llu\n",(unsigned long long)p->nr_sects);
 240 }
 241 static ssize_t part_stat_read(struct hd_struct * p, char *page)
 242 {
 243         return sprintf(page, "%8u %8llu %8u %8llu\n",
 244                        p->ios[0], (unsigned long long)p->sectors[0],
 245                        p->ios[1], (unsigned long long)p->sectors[1]);
 246 }
 247 static struct part_attribute part_attr_uevent = {
 248         .attr = {.name = "uevent", .mode = S_IWUSR },
 249         .store  = part_uevent_store
 250 };
 251 static struct part_attribute part_attr_dev = {
 252         .attr = {.name = "dev", .mode = S_IRUGO },
 253         .show   = part_dev_read
 254 };
 255 static struct part_attribute part_attr_start = {
 256         .attr = {.name = "start", .mode = S_IRUGO },
 257         .show   = part_start_read
 258 };
 259 static struct part_attribute part_attr_size = {
 260         .attr = {.name = "size", .mode = S_IRUGO },
 261         .show   = part_size_read
 262 };
 263 static struct part_attribute part_attr_stat = {
 264         .attr = {.name = "stat", .mode = S_IRUGO },
 265         .show   = part_stat_read
 266 };
 267
 268 static struct attribute * default_attrs[] = {
 269         &part_attr_uevent.attr,
 270         &part_attr_dev.attr,
 271         &part_attr_start.attr,
 272         &part_attr_size.attr,
 273         &part_attr_stat.attr,
 274         NULL,
 275 };
 276
 277 extern struct subsystem block_subsys;
 278
 279 static void part_release(struct kobject *kobj)
 280 {
 281         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 282         kfree(p);
 283 }
 284
 285 struct kobj_type ktype_part = {
 286         .release        = part_release,
 287         .default_attrs  = default_attrs,
 288         .sysfs_ops      = &part_sysfs_ops,
 289 };
 290
 291 static inline void partition_sysfs_add_subdir(struct hd_struct *p)
 292 {
 293         struct kobject *k;
 294
 295         k = kobject_get(&p->kobj);
 296         p->holder_dir = kobject_add_dir(k, "holders");
 297         kobject_put(k);
 298 }
 299
 300 static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
 301 {
 302         struct kobject *k;
 303
 304         k = kobject_get(&disk->kobj);
 305         disk->holder_dir = kobject_add_dir(k, "holders");
 306         disk->slave_dir = kobject_add_dir(k, "slaves");
 307         kobject_put(k);
 308 }
 309
 310 void delete_partition(struct gendisk *disk, int part)
 311 {
 312         struct hd_struct *p = disk->part[part-1];
 313         if (!p)
 314                 return;
 315         if (!p->nr_sects)
 316                 return;
 317         disk->part[part-1] = NULL;
 318         p->start_sect = 0;
 319         p->nr_sects = 0;
 320         p->ios[0] = p->ios[1] = 0;
 321         p->sectors[0] = p->sectors[1] = 0;
 322         sysfs_remove_link(&p->kobj, "subsystem");
 323         if (p->holder_dir)
 324                 kobject_unregister(p->holder_dir);
 325         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 326         kobject_del(&p->kobj);
 327         kobject_put(&p->kobj);
 328 }
 329
 330 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len)
 331 {
 332         struct hd_struct *p;
 333
 334         p = kmalloc(sizeof(*p), GFP_KERNEL);
 335         if (!p)
 336                 return;
 337
 338         memset(p, 0, sizeof(*p));
 339         p->start_sect = start;
 340         p->nr_sects = len;
 341         p->partno = part;
 342         p->policy = disk->policy;
 343
 344         if (isdigit(disk->kobj.name[strlen(disk->kobj.name)-1]))
 345                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%sp%d",disk->kobj.name,part);
 346         else
 347                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%s%d",disk->kobj.name,part);
 348         p->kobj.parent = &disk->kobj;
 349         p->kobj.ktype = &ktype_part;
 350         kobject_init(&p->kobj);
 351         kobject_add(&p->kobj);
 352         if (!disk->part_uevent_suppress)
 353                 kobject_uevent(&p->kobj, KOBJ_ADD);
 354         sysfs_create_link(&p->kobj, &block_subsys.kset.kobj, "subsystem");
 355         partition_sysfs_add_subdir(p);
 356         disk->part[part-1] = p;
 357 }
 358
 359 static char *make_block_name(struct gendisk *disk)
 360 {
 361         char *name;
 362         static char *block_str = "block:";
 363         int size;
 364         char *s;
 365
 366         size = strlen(block_str) + strlen(disk->disk_name) + 1;
 367         name = kmalloc(size, GFP_KERNEL);
 368         if (!name)
 369                 return NULL;
 370         strcpy(name, block_str);
 371         strcat(name, disk->disk_name);
 372         /* ewww... some of these buggers have / in name... */
 373         s = strchr(name, '/');
 374         if (s)
 375                 *s = '!';
 376         return name;
 377 }
 378
 379 static int disk_sysfs_symlinks(struct gendisk *disk)
 380 {
 381         struct device *target = get_device(disk->driverfs_dev);
 382         int err;
 383         char *disk_name = NULL;
 384
 385         if (target) {
 386                 disk_name = make_block_name(disk);
 387                 if (!disk_name) {
 388                         err = -ENOMEM;
 389                         goto err_out;
 390                 }
 391
 392                 err = sysfs_create_link(&disk->kobj, &target->kobj, "device");
 393                 if (err)
 394                         goto err_out_disk_name;
 395
 396                 err = sysfs_create_link(&target->kobj, &disk->kobj, disk_name);
 397                 if (err)
 398                         goto err_out_dev_link;
 399         }
 400
 401         err = sysfs_create_link(&disk->kobj, &block_subsys.kset.kobj,
 402                                 "subsystem");
 403         if (err)
 404                 goto err_out_disk_name_lnk;
 405
 406         kfree(disk_name);
 407
 408         return 0;
 409
 410 err_out_disk_name_lnk:
 411         if (target) {
 412                 sysfs_remove_link(&target->kobj, disk_name);
 413 err_out_dev_link:
 414                 sysfs_remove_link(&disk->kobj, "device");
 415 err_out_disk_name:
 416                 kfree(disk_name);
 417 err_out:
 418                 put_device(target);
 419         }
 420         return err;
 421 }
 422
 423 /* Not exported, helper to add_disk(). */
 424 void register_disk(struct gendisk *disk)
 425 {
 426         struct block_device *bdev;
 427         char *s;
 428         int i;
 429         struct hd_struct *p;
 430         int err;
 431
 432         strlcpy(disk->kobj.name,disk->disk_name,KOBJ_NAME_LEN);
 433         /* ewww... some of these buggers have / in name... */
 434         s = strchr(disk->kobj.name, '/');
 435         if (s)
 436                 *s = '!';
 437         if ((err = kobject_add(&disk->kobj)))
 438                 return;
 439         err = disk_sysfs_symlinks(disk);
 440         if (err) {
 441                 kobject_del(&disk->kobj);
 442                 return;
 443         }
 444         disk_sysfs_add_subdirs(disk);
 445
 446         /* No minors to use for partitions */
 447         if (disk->minors == 1)
 448                 goto exit;
 449
 450         /* No such device (e.g., media were just removed) */
 451         if (!get_capacity(disk))
 452                 goto exit;
 453
 454         bdev = bdget_disk(disk, 0);
 455         if (!bdev)
 456                 goto exit;
 457
 458         /* scan partition table, but suppress uevents */
 459         bdev->bd_invalidated = 1;
 460         disk->part_uevent_suppress = 1;
 461         err = blkdev_get(bdev, FMODE_READ, 0);
 462         disk->part_uevent_suppress = 0;
 463         if (err < 0)
 464                 goto exit;
 465         blkdev_put(bdev);
 466
 467 exit:
 468         /* announce disk after possible partitions are already created */
 469         kobject_uevent(&disk->kobj, KOBJ_ADD);
 470
 471         /* announce possible partitions */
 472         for (i = 1; i < disk->minors; i++) {
 473                 p = disk->part[i-1];
 474                 if (!p || !p->nr_sects)
 475                         continue;
 476                 kobject_uevent(&p->kobj, KOBJ_ADD);
 477         }
 478 }
 479
 480 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 481 {
 482         struct parsed_partitions *state;
 483         int p, res;
 484
 485         if (bdev->bd_part_count)
 486                 return -EBUSY;
 487         res = invalidate_partition(disk, 0);
 488         if (res)
 489                 return res;
 490         bdev->bd_invalidated = 0;
 491         for (p = 1; p < disk->minors; p++)
 492                 delete_partition(disk, p);
 493         if (disk->fops->revalidate_disk)
 494                 disk->fops->revalidate_disk(disk);
 495         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 496                 return 0;
 497         for (p = 1; p < state->limit; p++) {
 498                 sector_t size = state->parts[p].size;
 499                 sector_t from = state->parts[p].from;
 500                 if (!size)
 501                         continue;
 502                 if (from + size > get_capacity(disk)) {
 503                         printk(" %s: p%d exceeds device capacity\n",
 504                                 disk->disk_name, p);
 505                 }
 506                 add_partition(disk, p, from, size);
 507 #ifdef CONFIG_BLK_DEV_MD
 508                 if (state->parts[p].flags)
 509                         md_autodetect_dev(bdev->bd_dev+p);
 510 #endif
 511         }
 512         kfree(state);
 513         return 0;
 514 }
 515
 516 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 517 {
 518         struct address_space *mapping = bdev->bd_inode->i_mapping;
 519         struct page *page;
 520
 521         page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 522                                  NULL);
 523         if (!IS_ERR(page)) {
 524                 wait_on_page_locked(page);
 525                 if (!PageUptodate(page))
 526                         goto fail;
 527                 if (PageError(page))
 528                         goto fail;
 529                 p->v = page;
 530                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 531 fail:
 532                 page_cache_release(page);
 533         }
 534         p->v = NULL;
 535         return NULL;
 536 }
 537
 538 EXPORT_SYMBOL(read_dev_sector);
 539
 540 void del_gendisk(struct gendisk *disk)
 541 {
 542         int p;
 543
 544         /* invalidate stuff */
 545         for (p = disk->minors - 1; p > 0; p--) {
 546                 invalidate_partition(disk, p);
 547                 delete_partition(disk, p);
 548         }
 549         invalidate_partition(disk, 0);
 550         disk->capacity = 0;
 551         disk->flags &= ~GENHD_FL_UP;
 552         unlink_gendisk(disk);
 553         disk_stat_set_all(disk, 0);
 554         disk->stamp = 0;
 555
 556         kobject_uevent(&disk->kobj, KOBJ_REMOVE);
 557         if (disk->holder_dir)
 558                 kobject_unregister(disk->holder_dir);
 559         if (disk->slave_dir)
 560                 kobject_unregister(disk->slave_dir);
 561         if (disk->driverfs_dev) {
 562                 char *disk_name = make_block_name(disk);
 563                 sysfs_remove_link(&disk->kobj, "device");
 564                 if (disk_name) {
 565                         sysfs_remove_link(&disk->driverfs_dev->kobj, disk_name);
 566                         kfree(disk_name);
 567                 }
 568                 put_device(disk->driverfs_dev);
 569                 disk->driverfs_dev = NULL;
 570         }
 571         sysfs_remove_link(&disk->kobj, "subsystem");
 572         kobject_del(&disk->kobj);
 573 }