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         sysfs_remove_link(&p->kobj, "subsystem");
 333         if (p->holder_dir)
 334                 kobject_unregister(p->holder_dir);
 335         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 336         kobject_del(&p->kobj);
 337         kobject_put(&p->kobj);
 338 }
 339
 340 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len)
 341 {
 342         struct hd_struct *p;
 343
 344         p = kmalloc(sizeof(*p), GFP_KERNEL);
 345         if (!p)
 346                 return;
 347
 348         memset(p, 0, sizeof(*p));
 349         p->start_sect = start;
 350         p->nr_sects = len;
 351         p->partno = part;
 352
 353         devfs_mk_bdev(MKDEV(disk->major, disk->first_minor + part),
 354                         S_IFBLK|S_IRUSR|S_IWUSR,
 355                         "%s/part%d", disk->devfs_name, part);
 356
 357         if (isdigit(disk->kobj.name[strlen(disk->kobj.name)-1]))
 358                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%sp%d",disk->kobj.name,part);
 359         else
 360                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%s%d",disk->kobj.name,part);
 361         p->kobj.parent = &disk->kobj;
 362         p->kobj.ktype = &ktype_part;
 363         kobject_init(&p->kobj);
 364         kobject_add(&p->kobj);
 365         if (!disk->part_uevent_suppress)
 366                 kobject_uevent(&p->kobj, KOBJ_ADD);
 367         sysfs_create_link(&p->kobj, &block_subsys.kset.kobj, "subsystem");
 368         partition_sysfs_add_subdir(p);
 369         disk->part[part-1] = p;
 370 }
 371
 372 static char *make_block_name(struct gendisk *disk)
 373 {
 374         char *name;
 375         static char *block_str = "block:";
 376         int size;
 377         char *s;
 378
 379         size = strlen(block_str) + strlen(disk->disk_name) + 1;
 380         name = kmalloc(size, GFP_KERNEL);
 381         if (!name)
 382                 return NULL;
 383         strcpy(name, block_str);
 384         strcat(name, disk->disk_name);
 385         /* ewww... some of these buggers have / in name... */
 386         s = strchr(name, '/');
 387         if (s)
 388                 *s = '!';
 389         return name;
 390 }
 391
 392 static void disk_sysfs_symlinks(struct gendisk *disk)
 393 {
 394         struct device *target = get_device(disk->driverfs_dev);
 395         if (target) {
 396                 char *disk_name = make_block_name(disk);
 397                 sysfs_create_link(&disk->kobj,&target->kobj,"device");
 398                 if (disk_name) {
 399                         sysfs_create_link(&target->kobj,&disk->kobj,disk_name);
 400                         kfree(disk_name);
 401                 }
 402         }
 403         sysfs_create_link(&disk->kobj, &block_subsys.kset.kobj, "subsystem");
 404 }
 405
 406 /* Not exported, helper to add_disk(). */
 407 void register_disk(struct gendisk *disk)
 408 {
 409         struct block_device *bdev;
 410         char *s;
 411         int i;
 412         struct hd_struct *p;
 413         int err;
 414
 415         strlcpy(disk->kobj.name,disk->disk_name,KOBJ_NAME_LEN);
 416         /* ewww... some of these buggers have / in name... */
 417         s = strchr(disk->kobj.name, '/');
 418         if (s)
 419                 *s = '!';
 420         if ((err = kobject_add(&disk->kobj)))
 421                 return;
 422         disk_sysfs_symlinks(disk);
 423         disk_sysfs_add_subdirs(disk);
 424
 425         /* No minors to use for partitions */
 426         if (disk->minors == 1) {
 427                 if (disk->devfs_name[0] != '\0')
 428                         devfs_add_disk(disk);
 429                 goto exit;
 430         }
 431
 432         /* always add handle for the whole disk */
 433         devfs_add_partitioned(disk);
 434
 435         /* No such device (e.g., media were just removed) */
 436         if (!get_capacity(disk))
 437                 goto exit;
 438
 439         bdev = bdget_disk(disk, 0);
 440         if (!bdev)
 441                 goto exit;
 442
 443         /* scan partition table, but suppress uevents */
 444         bdev->bd_invalidated = 1;
 445         disk->part_uevent_suppress = 1;
 446         err = blkdev_get(bdev, FMODE_READ, 0);
 447         disk->part_uevent_suppress = 0;
 448         if (err < 0)
 449                 goto exit;
 450         blkdev_put(bdev);
 451
 452 exit:
 453         /* announce disk after possible partitions are already created */
 454         kobject_uevent(&disk->kobj, KOBJ_ADD);
 455
 456         /* announce possible partitions */
 457         for (i = 1; i < disk->minors; i++) {
 458                 p = disk->part[i-1];
 459                 if (!p || !p->nr_sects)
 460                         continue;
 461                 kobject_uevent(&p->kobj, KOBJ_ADD);
 462         }
 463 }
 464
 465 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 466 {
 467         struct parsed_partitions *state;
 468         int p, res;
 469
 470         if (bdev->bd_part_count)
 471                 return -EBUSY;
 472         res = invalidate_partition(disk, 0);
 473         if (res)
 474                 return res;
 475         bdev->bd_invalidated = 0;
 476         for (p = 1; p < disk->minors; p++)
 477                 delete_partition(disk, p);
 478         if (disk->fops->revalidate_disk)
 479                 disk->fops->revalidate_disk(disk);
 480         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 481                 return 0;
 482         for (p = 1; p < state->limit; p++) {
 483                 sector_t size = state->parts[p].size;
 484                 sector_t from = state->parts[p].from;
 485                 if (!size)
 486                         continue;
 487                 add_partition(disk, p, from, size);
 488 #ifdef CONFIG_BLK_DEV_MD
 489                 if (state->parts[p].flags)
 490                         md_autodetect_dev(bdev->bd_dev+p);
 491 #endif
 492         }
 493         kfree(state);
 494         return 0;
 495 }
 496
 497 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 498 {
 499         struct address_space *mapping = bdev->bd_inode->i_mapping;
 500         struct page *page;
 501
 502         page = read_cache_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 503                         (filler_t *)mapping->a_ops->readpage, NULL);
 504         if (!IS_ERR(page)) {
 505                 wait_on_page_locked(page);
 506                 if (!PageUptodate(page))
 507                         goto fail;
 508                 if (PageError(page))
 509                         goto fail;
 510                 p->v = page;
 511                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 512 fail:
 513                 page_cache_release(page);
 514         }
 515         p->v = NULL;
 516         return NULL;
 517 }
 518
 519 EXPORT_SYMBOL(read_dev_sector);
 520
 521 void del_gendisk(struct gendisk *disk)
 522 {
 523         int p;
 524
 525         /* invalidate stuff */
 526         for (p = disk->minors - 1; p > 0; p--) {
 527                 invalidate_partition(disk, p);
 528                 delete_partition(disk, p);
 529         }
 530         invalidate_partition(disk, 0);
 531         disk->capacity = 0;
 532         disk->flags &= ~GENHD_FL_UP;
 533         unlink_gendisk(disk);
 534         disk_stat_set_all(disk, 0);
 535         disk->stamp = 0;
 536
 537         devfs_remove_disk(disk);
 538
 539         kobject_uevent(&disk->kobj, KOBJ_REMOVE);
 540         if (disk->holder_dir)
 541                 kobject_unregister(disk->holder_dir);
 542         if (disk->slave_dir)
 543                 kobject_unregister(disk->slave_dir);
 544         if (disk->driverfs_dev) {
 545                 char *disk_name = make_block_name(disk);
 546                 sysfs_remove_link(&disk->kobj, "device");
 547                 if (disk_name) {
 548                         sysfs_remove_link(&disk->driverfs_dev->kobj, disk_name);
 549                         kfree(disk_name);
 550                 }
 551                 put_device(disk->driverfs_dev);
 552                 disk->driverfs_dev = NULL;
 553         }
 554         sysfs_remove_link(&disk->kobj, "subsystem");
 555         kobject_del(&disk->kobj);
 556 }