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/devfs_fs_kernel.h>
  22
  23 #include "check.h"
  24 #include "devfs.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
  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         NULL
 111 };
 112
 113 /*
 114  * disk_name() is used by partition check code and the genhd driver.
 115  * It formats the devicename of the indicated disk into
 116  * the supplied buffer (of size at least 32), and returns
 117  * a pointer to that same buffer (for convenience).
 118  */
 119
 120 char *disk_name(struct gendisk *hd, int part, char *buf)
 121 {
 122         if (!part)
 123                 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
 124         else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
 125                 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
 126         else
 127                 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);
 128
 129         return buf;
 130 }
 131
 132 const char *bdevname(struct block_device *bdev, char *buf)
 133 {
 134         int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
 135         return disk_name(bdev->bd_disk, part, buf);
 136 }
 137
 138 EXPORT_SYMBOL(bdevname);
 139
 140 /*
 141  * There's very little reason to use this, you should really
 142  * have a struct block_device just about everywhere and use
 143  * bdevname() instead.
 144  */
 145 const char *__bdevname(dev_t dev, char *buffer)
 146 {
 147         scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
 148                                 MAJOR(dev), MINOR(dev));
 149         return buffer;
 150 }
 151
 152 EXPORT_SYMBOL(__bdevname);
 153
 154 static struct parsed_partitions *
 155 check_partition(struct gendisk *hd, struct block_device *bdev)
 156 {
 157         struct parsed_partitions *state;
 158         int i, res;
 159
 160         state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 161         if (!state)
 162                 return NULL;
 163
 164 #ifdef CONFIG_DEVFS_FS
 165         if (hd->devfs_name[0] != '\0') {
 166                 printk(KERN_INFO " /dev/%s:", hd->devfs_name);
 167                 sprintf(state->name, "p");
 168         }
 169 #endif
 170         else {
 171                 disk_name(hd, 0, state->name);
 172                 printk(KERN_INFO " %s:", state->name);
 173                 if (isdigit(state->name[strlen(state->name)-1]))
 174                         sprintf(state->name, "p");
 175         }
 176         state->limit = hd->minors;
 177         i = res = 0;
 178         while (!res && check_part[i]) {
 179                 memset(&state->parts, 0, sizeof(state->parts));
 180                 res = check_part[i++](state, bdev);
 181         }
 182         if (res > 0)
 183                 return state;
 184         if (!res)
 185                 printk(" unknown partition table\n");
 186         else if (warn_no_part)
 187                 printk(" unable to read partition table\n");
 188         kfree(state);
 189         return NULL;
 190 }
 191
 192 /*
 193  * sysfs bindings for partitions
 194  */
 195
 196 struct part_attribute {
 197         struct attribute attr;
 198         ssize_t (*show)(struct hd_struct *,char *);
 199         ssize_t (*store)(struct hd_struct *,const char *, size_t);
 200 };
 201
 202 static ssize_t
 203 part_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
 204 {
 205         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 206         struct part_attribute * part_attr = container_of(attr,struct part_attribute,attr);
 207         ssize_t ret = 0;
 208         if (part_attr->show)
 209                 ret = part_attr->show(p, page);
 210         return ret;
 211 }
 212 static ssize_t
 213 part_attr_store(struct kobject * kobj, struct attribute * attr,
 214                 const char *page, size_t count)
 215 {
 216         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 217         struct part_attribute * part_attr = container_of(attr,struct part_attribute,attr);
 218         ssize_t ret = 0;
 219
 220         if (part_attr->store)
 221                 ret = part_attr->store(p, page, count);
 222         return ret;
 223 }
 224
 225 static struct sysfs_ops part_sysfs_ops = {
 226         .show   =       part_attr_show,
 227         .store  =       part_attr_store,
 228 };
 229
 230 static ssize_t part_uevent_store(struct hd_struct * p,
 231                                  const char *page, size_t count)
 232 {
 233         kobject_uevent(&p->kobj, KOBJ_ADD);
 234         return count;
 235 }
 236 static ssize_t part_dev_read(struct hd_struct * p, char *page)
 237 {
 238         struct gendisk *disk = container_of(p->kobj.parent,struct gendisk,kobj);
 239         dev_t dev = MKDEV(disk->major, disk->first_minor + p->partno);
 240         return print_dev_t(page, dev);
 241 }
 242 static ssize_t part_start_read(struct hd_struct * p, char *page)
 243 {
 244         return sprintf(page, "%llu\n",(unsigned long long)p->start_sect);
 245 }
 246 static ssize_t part_size_read(struct hd_struct * p, char *page)
 247 {
 248         return sprintf(page, "%llu\n",(unsigned long long)p->nr_sects);
 249 }
 250 static ssize_t part_stat_read(struct hd_struct * p, char *page)
 251 {
 252         return sprintf(page, "%8u %8llu %8u %8llu\n",
 253                        p->ios[0], (unsigned long long)p->sectors[0],
 254                        p->ios[1], (unsigned long long)p->sectors[1]);
 255 }
 256 static struct part_attribute part_attr_uevent = {
 257         .attr = {.name = "uevent", .mode = S_IWUSR },
 258         .store  = part_uevent_store
 259 };
 260 static struct part_attribute part_attr_dev = {
 261         .attr = {.name = "dev", .mode = S_IRUGO },
 262         .show   = part_dev_read
 263 };
 264 static struct part_attribute part_attr_start = {
 265         .attr = {.name = "start", .mode = S_IRUGO },
 266         .show   = part_start_read
 267 };
 268 static struct part_attribute part_attr_size = {
 269         .attr = {.name = "size", .mode = S_IRUGO },
 270         .show   = part_size_read
 271 };
 272 static struct part_attribute part_attr_stat = {
 273         .attr = {.name = "stat", .mode = S_IRUGO },
 274         .show   = part_stat_read
 275 };
 276
 277 static struct attribute * default_attrs[] = {
 278         &part_attr_uevent.attr,
 279         &part_attr_dev.attr,
 280         &part_attr_start.attr,
 281         &part_attr_size.attr,
 282         &part_attr_stat.attr,
 283         NULL,
 284 };
 285
 286 extern struct subsystem block_subsys;
 287
 288 static void part_release(struct kobject *kobj)
 289 {
 290         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 291         kfree(p);
 292 }
 293
 294 struct kobj_type ktype_part = {
 295         .release        = part_release,
 296         .default_attrs  = default_attrs,
 297         .sysfs_ops      = &part_sysfs_ops,
 298 };
 299
 300 static inline void partition_sysfs_add_subdir(struct hd_struct *p)
 301 {
 302         struct kobject *k;
 303
 304         k = kobject_get(&p->kobj);
 305         p->holder_dir = kobject_add_dir(k, "holders");
 306         kobject_put(k);
 307 }
 308
 309 static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
 310 {
 311         struct kobject *k;
 312
 313         k = kobject_get(&disk->kobj);
 314         disk->holder_dir = kobject_add_dir(k, "holders");
 315         disk->slave_dir = kobject_add_dir(k, "slaves");
 316         kobject_put(k);
 317 }
 318
 319 void delete_partition(struct gendisk *disk, int part)
 320 {
 321         struct hd_struct *p = disk->part[part-1];
 322         if (!p)
 323                 return;
 324         if (!p->nr_sects)
 325                 return;
 326         disk->part[part-1] = NULL;
 327         p->start_sect = 0;
 328         p->nr_sects = 0;
 329         p->ios[0] = p->ios[1] = 0;
 330         p->sectors[0] = p->sectors[1] = 0;
 331         devfs_remove("%s/part%d", disk->devfs_name, part);
 332         if (p->holder_dir)
 333                 kobject_unregister(p->holder_dir);
 334         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 335         kobject_del(&p->kobj);
 336         kobject_put(&p->kobj);
 337 }
 338
 339 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len)
 340 {
 341         struct hd_struct *p;
 342
 343         p = kmalloc(sizeof(*p), GFP_KERNEL);
 344         if (!p)
 345                 return;
 346
 347         memset(p, 0, sizeof(*p));
 348         p->start_sect = start;
 349         p->nr_sects = len;
 350         p->partno = part;
 351
 352         devfs_mk_bdev(MKDEV(disk->major, disk->first_minor + part),
 353                         S_IFBLK|S_IRUSR|S_IWUSR,
 354                         "%s/part%d", disk->devfs_name, part);
 355
 356         if (isdigit(disk->kobj.name[strlen(disk->kobj.name)-1]))
 357                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%sp%d",disk->kobj.name,part);
 358         else
 359                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%s%d",disk->kobj.name,part);
 360         p->kobj.parent = &disk->kobj;
 361         p->kobj.ktype = &ktype_part;
 362         kobject_init(&p->kobj);
 363         kobject_add(&p->kobj);
 364         if (!disk->part_uevent_suppress)
 365                 kobject_uevent(&p->kobj, KOBJ_ADD);
 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 void disk_sysfs_symlinks(struct gendisk *disk)
 391 {
 392         struct device *target = get_device(disk->driverfs_dev);
 393         if (target) {
 394                 char *disk_name = make_block_name(disk);
 395                 sysfs_create_link(&disk->kobj,&target->kobj,"device");
 396                 if (disk_name) {
 397                         sysfs_create_link(&target->kobj,&disk->kobj,disk_name);
 398                         kfree(disk_name);
 399                 }
 400         }
 401 }
 402
 403 /* Not exported, helper to add_disk(). */
 404 void register_disk(struct gendisk *disk)
 405 {
 406         struct block_device *bdev;
 407         char *s;
 408         int i;
 409         struct hd_struct *p;
 410         int err;
 411
 412         strlcpy(disk->kobj.name,disk->disk_name,KOBJ_NAME_LEN);
 413         /* ewww... some of these buggers have / in name... */
 414         s = strchr(disk->kobj.name, '/');
 415         if (s)
 416                 *s = '!';
 417         if ((err = kobject_add(&disk->kobj)))
 418                 return;
 419         disk_sysfs_symlinks(disk);
 420         disk_sysfs_add_subdirs(disk);
 421
 422         /* No minors to use for partitions */
 423         if (disk->minors == 1) {
 424                 if (disk->devfs_name[0] != '\0')
 425                         devfs_add_disk(disk);
 426                 goto exit;
 427         }
 428
 429         /* always add handle for the whole disk */
 430         devfs_add_partitioned(disk);
 431
 432         /* No such device (e.g., media were just removed) */
 433         if (!get_capacity(disk))
 434                 goto exit;
 435
 436         bdev = bdget_disk(disk, 0);
 437         if (!bdev)
 438                 goto exit;
 439
 440         /* scan partition table, but suppress uevents */
 441         bdev->bd_invalidated = 1;
 442         disk->part_uevent_suppress = 1;
 443         err = blkdev_get(bdev, FMODE_READ, 0);
 444         disk->part_uevent_suppress = 0;
 445         if (err < 0)
 446                 goto exit;
 447         blkdev_put(bdev);
 448
 449 exit:
 450         /* announce disk after possible partitions are already created */
 451         kobject_uevent(&disk->kobj, KOBJ_ADD);
 452
 453         /* announce possible partitions */
 454         for (i = 1; i < disk->minors; i++) {
 455                 p = disk->part[i-1];
 456                 if (!p || !p->nr_sects)
 457                         continue;
 458                 kobject_uevent(&p->kobj, KOBJ_ADD);
 459         }
 460 }
 461
 462 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 463 {
 464         struct parsed_partitions *state;
 465         int p, res;
 466
 467         if (bdev->bd_part_count)
 468                 return -EBUSY;
 469         res = invalidate_partition(disk, 0);
 470         if (res)
 471                 return res;
 472         bdev->bd_invalidated = 0;
 473         for (p = 1; p < disk->minors; p++)
 474                 delete_partition(disk, p);
 475         if (disk->fops->revalidate_disk)
 476                 disk->fops->revalidate_disk(disk);
 477         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 478                 return 0;
 479         for (p = 1; p < state->limit; p++) {
 480                 sector_t size = state->parts[p].size;
 481                 sector_t from = state->parts[p].from;
 482                 if (!size)
 483                         continue;
 484                 add_partition(disk, p, from, size);
 485 #ifdef CONFIG_BLK_DEV_MD
 486                 if (state->parts[p].flags)
 487                         md_autodetect_dev(bdev->bd_dev+p);
 488 #endif
 489         }
 490         kfree(state);
 491         return 0;
 492 }
 493
 494 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 495 {
 496         struct address_space *mapping = bdev->bd_inode->i_mapping;
 497         struct page *page;
 498
 499         page = read_cache_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 500                         (filler_t *)mapping->a_ops->readpage, NULL);
 501         if (!IS_ERR(page)) {
 502                 wait_on_page_locked(page);
 503                 if (!PageUptodate(page))
 504                         goto fail;
 505                 if (PageError(page))
 506                         goto fail;
 507                 p->v = page;
 508                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 509 fail:
 510                 page_cache_release(page);
 511         }
 512         p->v = NULL;
 513         return NULL;
 514 }
 515
 516 EXPORT_SYMBOL(read_dev_sector);
 517
 518 void del_gendisk(struct gendisk *disk)
 519 {
 520         int p;
 521
 522         /* invalidate stuff */
 523         for (p = disk->minors - 1; p > 0; p--) {
 524                 invalidate_partition(disk, p);
 525                 delete_partition(disk, p);
 526         }
 527         invalidate_partition(disk, 0);
 528         disk->capacity = 0;
 529         disk->flags &= ~GENHD_FL_UP;
 530         unlink_gendisk(disk);
 531         disk_stat_set_all(disk, 0);
 532         disk->stamp = 0;
 533
 534         devfs_remove_disk(disk);
 535
 536         kobject_uevent(&disk->kobj, KOBJ_REMOVE);
 537         if (disk->holder_dir)
 538                 kobject_unregister(disk->holder_dir);
 539         if (disk->slave_dir)
 540                 kobject_unregister(disk->slave_dir);
 541         if (disk->driverfs_dev) {
 542                 char *disk_name = make_block_name(disk);
 543                 sysfs_remove_link(&disk->kobj, "device");
 544                 if (disk_name) {
 545                         sysfs_remove_link(&disk->driverfs_dev->kobj, disk_name);
 546                         kfree(disk_name);
 547                 }
 548                 put_device(disk->driverfs_dev);
 549                 disk->driverfs_dev = NULL;
 550         }
 551         kobject_del(&disk->kobj);
 552 }