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 static struct attribute * default_attrs[] = {
 280         &part_attr_uevent.attr,
 281         &part_attr_dev.attr,
 282         &part_attr_start.attr,
 283         &part_attr_size.attr,
 284         &part_attr_stat.attr,
 285         NULL,
 286 };
 287
 288 extern struct subsystem block_subsys;
 289
 290 static void part_release(struct kobject *kobj)
 291 {
 292         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 293         kfree(p);
 294 }
 295
 296 struct kobj_type ktype_part = {
 297         .release        = part_release,
 298         .default_attrs  = default_attrs,
 299         .sysfs_ops      = &part_sysfs_ops,
 300 };
 301
 302 static inline void partition_sysfs_add_subdir(struct hd_struct *p)
 303 {
 304         struct kobject *k;
 305
 306         k = kobject_get(&p->kobj);
 307         p->holder_dir = kobject_add_dir(k, "holders");
 308         kobject_put(k);
 309 }
 310
 311 static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
 312 {
 313         struct kobject *k;
 314
 315         k = kobject_get(&disk->kobj);
 316         disk->holder_dir = kobject_add_dir(k, "holders");
 317         disk->slave_dir = kobject_add_dir(k, "slaves");
 318         kobject_put(k);
 319 }
 320
 321 void delete_partition(struct gendisk *disk, int part)
 322 {
 323         struct hd_struct *p = disk->part[part-1];
 324         if (!p)
 325                 return;
 326         if (!p->nr_sects)
 327                 return;
 328         disk->part[part-1] = NULL;
 329         p->start_sect = 0;
 330         p->nr_sects = 0;
 331         p->ios[0] = p->ios[1] = 0;
 332         p->sectors[0] = p->sectors[1] = 0;
 333         sysfs_remove_link(&p->kobj, "subsystem");
 334         if (p->holder_dir)
 335                 kobject_unregister(p->holder_dir);
 336         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 337         kobject_del(&p->kobj);
 338         kobject_put(&p->kobj);
 339 }
 340
 341 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len)
 342 {
 343         struct hd_struct *p;
 344
 345         p = kmalloc(sizeof(*p), GFP_KERNEL);
 346         if (!p)
 347                 return;
 348
 349         memset(p, 0, sizeof(*p));
 350         p->start_sect = start;
 351         p->nr_sects = len;
 352         p->partno = part;
 353         p->policy = disk->policy;
 354
 355         if (isdigit(disk->kobj.name[strlen(disk->kobj.name)-1]))
 356                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%sp%d",disk->kobj.name,part);
 357         else
 358                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%s%d",disk->kobj.name,part);
 359         p->kobj.parent = &disk->kobj;
 360         p->kobj.ktype = &ktype_part;
 361         kobject_init(&p->kobj);
 362         kobject_add(&p->kobj);
 363         if (!disk->part_uevent_suppress)
 364                 kobject_uevent(&p->kobj, KOBJ_ADD);
 365         sysfs_create_link(&p->kobj, &block_subsys.kset.kobj, "subsystem");
 366         partition_sysfs_add_subdir(p);
 367         disk->part[part-1] = p;
 368 }
 369
 370 static char *make_block_name(struct gendisk *disk)
 371 {
 372         char *name;
 373         static char *block_str = "block:";
 374         int size;
 375         char *s;
 376
 377         size = strlen(block_str) + strlen(disk->disk_name) + 1;
 378         name = kmalloc(size, GFP_KERNEL);
 379         if (!name)
 380                 return NULL;
 381         strcpy(name, block_str);
 382         strcat(name, disk->disk_name);
 383         /* ewww... some of these buggers have / in name... */
 384         s = strchr(name, '/');
 385         if (s)
 386                 *s = '!';
 387         return name;
 388 }
 389
 390 static int disk_sysfs_symlinks(struct gendisk *disk)
 391 {
 392         struct device *target = get_device(disk->driverfs_dev);
 393         int err;
 394         char *disk_name = NULL;
 395
 396         if (target) {
 397                 disk_name = make_block_name(disk);
 398                 if (!disk_name) {
 399                         err = -ENOMEM;
 400                         goto err_out;
 401                 }
 402
 403                 err = sysfs_create_link(&disk->kobj, &target->kobj, "device");
 404                 if (err)
 405                         goto err_out_disk_name;
 406
 407                 err = sysfs_create_link(&target->kobj, &disk->kobj, disk_name);
 408                 if (err)
 409                         goto err_out_dev_link;
 410         }
 411
 412         err = sysfs_create_link(&disk->kobj, &block_subsys.kset.kobj,
 413                                 "subsystem");
 414         if (err)
 415                 goto err_out_disk_name_lnk;
 416
 417         kfree(disk_name);
 418
 419         return 0;
 420
 421 err_out_disk_name_lnk:
 422         if (target) {
 423                 sysfs_remove_link(&target->kobj, disk_name);
 424 err_out_dev_link:
 425                 sysfs_remove_link(&disk->kobj, "device");
 426 err_out_disk_name:
 427                 kfree(disk_name);
 428 err_out:
 429                 put_device(target);
 430         }
 431         return err;
 432 }
 433
 434 /* Not exported, helper to add_disk(). */
 435 void register_disk(struct gendisk *disk)
 436 {
 437         struct block_device *bdev;
 438         char *s;
 439         int i;
 440         struct hd_struct *p;
 441         int err;
 442
 443         strlcpy(disk->kobj.name,disk->disk_name,KOBJ_NAME_LEN);
 444         /* ewww... some of these buggers have / in name... */
 445         s = strchr(disk->kobj.name, '/');
 446         if (s)
 447                 *s = '!';
 448         if ((err = kobject_add(&disk->kobj)))
 449                 return;
 450         err = disk_sysfs_symlinks(disk);
 451         if (err) {
 452                 kobject_del(&disk->kobj);
 453                 return;
 454         }
 455         disk_sysfs_add_subdirs(disk);
 456
 457         /* No minors to use for partitions */
 458         if (disk->minors == 1)
 459                 goto exit;
 460
 461         /* No such device (e.g., media were just removed) */
 462         if (!get_capacity(disk))
 463                 goto exit;
 464
 465         bdev = bdget_disk(disk, 0);
 466         if (!bdev)
 467                 goto exit;
 468
 469         /* scan partition table, but suppress uevents */
 470         bdev->bd_invalidated = 1;
 471         disk->part_uevent_suppress = 1;
 472         err = blkdev_get(bdev, FMODE_READ, 0);
 473         disk->part_uevent_suppress = 0;
 474         if (err < 0)
 475                 goto exit;
 476         blkdev_put(bdev);
 477
 478 exit:
 479         /* announce disk after possible partitions are already created */
 480         kobject_uevent(&disk->kobj, KOBJ_ADD);
 481
 482         /* announce possible partitions */
 483         for (i = 1; i < disk->minors; i++) {
 484                 p = disk->part[i-1];
 485                 if (!p || !p->nr_sects)
 486                         continue;
 487                 kobject_uevent(&p->kobj, KOBJ_ADD);
 488         }
 489 }
 490
 491 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 492 {
 493         struct parsed_partitions *state;
 494         int p, res;
 495
 496         if (bdev->bd_part_count)
 497                 return -EBUSY;
 498         res = invalidate_partition(disk, 0);
 499         if (res)
 500                 return res;
 501         bdev->bd_invalidated = 0;
 502         for (p = 1; p < disk->minors; p++)
 503                 delete_partition(disk, p);
 504         if (disk->fops->revalidate_disk)
 505                 disk->fops->revalidate_disk(disk);
 506         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 507                 return 0;
 508         if (IS_ERR(state))      /* I/O error reading the partition table */
 509                 return PTR_ERR(state);
 510         for (p = 1; p < state->limit; p++) {
 511                 sector_t size = state->parts[p].size;
 512                 sector_t from = state->parts[p].from;
 513                 if (!size)
 514                         continue;
 515                 if (from + size > get_capacity(disk)) {
 516                         printk(" %s: p%d exceeds device capacity\n",
 517                                 disk->disk_name, p);
 518                 }
 519                 add_partition(disk, p, from, size);
 520 #ifdef CONFIG_BLK_DEV_MD
 521                 if (state->parts[p].flags)
 522                         md_autodetect_dev(bdev->bd_dev+p);
 523 #endif
 524         }
 525         kfree(state);
 526         return 0;
 527 }
 528
 529 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 530 {
 531         struct address_space *mapping = bdev->bd_inode->i_mapping;
 532         struct page *page;
 533
 534         page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 535                                  NULL);
 536         if (!IS_ERR(page)) {
 537                 wait_on_page_locked(page);
 538                 if (!PageUptodate(page))
 539                         goto fail;
 540                 if (PageError(page))
 541                         goto fail;
 542                 p->v = page;
 543                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 544 fail:
 545                 page_cache_release(page);
 546         }
 547         p->v = NULL;
 548         return NULL;
 549 }
 550
 551 EXPORT_SYMBOL(read_dev_sector);
 552
 553 void del_gendisk(struct gendisk *disk)
 554 {
 555         int p;
 556
 557         /* invalidate stuff */
 558         for (p = disk->minors - 1; p > 0; p--) {
 559                 invalidate_partition(disk, p);
 560                 delete_partition(disk, p);
 561         }
 562         invalidate_partition(disk, 0);
 563         disk->capacity = 0;
 564         disk->flags &= ~GENHD_FL_UP;
 565         unlink_gendisk(disk);
 566         disk_stat_set_all(disk, 0);
 567         disk->stamp = 0;
 568
 569         kobject_uevent(&disk->kobj, KOBJ_REMOVE);
 570         if (disk->holder_dir)
 571                 kobject_unregister(disk->holder_dir);
 572         if (disk->slave_dir)
 573                 kobject_unregister(disk->slave_dir);
 574         if (disk->driverfs_dev) {
 575                 char *disk_name = make_block_name(disk);
 576                 sysfs_remove_link(&disk->kobj, "device");
 577                 if (disk_name) {
 578                         sysfs_remove_link(&disk->driverfs_dev->kobj, disk_name);
 579                         kfree(disk_name);
 580                 }
 581                 put_device(disk->driverfs_dev);
 582                 disk->driverfs_dev = NULL;
 583         }
 584         sysfs_remove_link(&disk->kobj, "subsystem");
 585         kobject_del(&disk->kobj);
 586 }