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
  39 #ifdef CONFIG_BLK_DEV_MD
  40 extern void md_autodetect_dev(dev_t dev);
  41 #endif
  42
  43 int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
  44
  45 static int (*check_part[])(struct parsed_partitions *, struct block_device *) = {
  46         /*
  47          * Probe partition formats with tables at disk address 0
  48          * that also have an ADFS boot block at 0xdc0.
  49          */
  50 #ifdef CONFIG_ACORN_PARTITION_ICS
  51         adfspart_check_ICS,
  52 #endif
  53 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
  54         adfspart_check_POWERTEC,
  55 #endif
  56 #ifdef CONFIG_ACORN_PARTITION_EESOX
  57         adfspart_check_EESOX,
  58 #endif
  59
  60         /*
  61          * Now move on to formats that only have partition info at
  62          * disk address 0xdc0.  Since these may also have stale
  63          * PC/BIOS partition tables, they need to come before
  64          * the msdos entry.
  65          */
  66 #ifdef CONFIG_ACORN_PARTITION_CUMANA
  67         adfspart_check_CUMANA,
  68 #endif
  69 #ifdef CONFIG_ACORN_PARTITION_ADFS
  70         adfspart_check_ADFS,
  71 #endif
  72
  73 #ifdef CONFIG_EFI_PARTITION
  74         efi_partition,          /* this must come before msdos */
  75 #endif
  76 #ifdef CONFIG_SGI_PARTITION
  77         sgi_partition,
  78 #endif
  79 #ifdef CONFIG_LDM_PARTITION
  80         ldm_partition,          /* this must come before msdos */
  81 #endif
  82 #ifdef CONFIG_NEC98_PARTITION
  83         nec98_partition,        /* must be come before `msdos_partition' */
  84 #endif
  85 #ifdef CONFIG_MSDOS_PARTITION
  86         msdos_partition,
  87 #endif
  88 #ifdef CONFIG_OSF_PARTITION
  89         osf_partition,
  90 #endif
  91 #ifdef CONFIG_SUN_PARTITION
  92         sun_partition,
  93 #endif
  94 #ifdef CONFIG_AMIGA_PARTITION
  95         amiga_partition,
  96 #endif
  97 #ifdef CONFIG_ATARI_PARTITION
  98         atari_partition,
  99 #endif
 100 #ifdef CONFIG_MAC_PARTITION
 101         mac_partition,
 102 #endif
 103 #ifdef CONFIG_ULTRIX_PARTITION
 104         ultrix_partition,
 105 #endif
 106 #ifdef CONFIG_IBM_PARTITION
 107         ibm_partition,
 108 #endif
 109         NULL
 110 };
 111
 112 /*
 113  * disk_name() is used by partition check code and the genhd driver.
 114  * It formats the devicename of the indicated disk into
 115  * the supplied buffer (of size at least 32), and returns
 116  * a pointer to that same buffer (for convenience).
 117  */
 118
 119 char *disk_name(struct gendisk *hd, int part, char *buf)
 120 {
 121         if (!part)
 122                 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
 123         else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
 124                 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
 125         else
 126                 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);
 127
 128         return buf;
 129 }
 130
 131 const char *bdevname(struct block_device *bdev, char *buf)
 132 {
 133         int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
 134         return disk_name(bdev->bd_disk, part, buf);
 135 }
 136
 137 EXPORT_SYMBOL(bdevname);
 138
 139 /*
 140  * There's very little reason to use this, you should really
 141  * have a struct block_device just about everywhere and use
 142  * bdevname() instead.
 143  */
 144 const char *__bdevname(dev_t dev, char *buffer)
 145 {
 146         scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
 147                                 MAJOR(dev), MINOR(dev));
 148         return buffer;
 149 }
 150
 151 EXPORT_SYMBOL(__bdevname);
 152
 153 static struct parsed_partitions *
 154 check_partition(struct gendisk *hd, struct block_device *bdev)
 155 {
 156         struct parsed_partitions *state;
 157         int i, res;
 158
 159         state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 160         if (!state)
 161                 return NULL;
 162
 163 #ifdef CONFIG_DEVFS_FS
 164         if (hd->devfs_name[0] != '\0') {
 165                 printk(KERN_INFO " /dev/%s:", hd->devfs_name);
 166                 sprintf(state->name, "p");
 167         }
 168 #endif
 169         else {
 170                 disk_name(hd, 0, state->name);
 171                 printk(KERN_INFO " %s:", state->name);
 172                 if (isdigit(state->name[strlen(state->name)-1]))
 173                         sprintf(state->name, "p");
 174         }
 175         state->limit = hd->minors;
 176         i = res = 0;
 177         while (!res && check_part[i]) {
 178                 memset(&state->parts, 0, sizeof(state->parts));
 179                 res = check_part[i++](state, bdev);
 180         }
 181         if (res > 0)
 182                 return state;
 183         if (!res)
 184                 printk(" unknown partition table\n");
 185         else if (warn_no_part)
 186                 printk(" unable to read partition table\n");
 187         kfree(state);
 188         return NULL;
 189 }
 190
 191 /*
 192  * sysfs bindings for partitions
 193  */
 194
 195 struct part_attribute {
 196         struct attribute attr;
 197         ssize_t (*show)(struct hd_struct *,char *);
 198 };
 199
 200 static ssize_t
 201 part_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
 202 {
 203         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 204         struct part_attribute * part_attr = container_of(attr,struct part_attribute,attr);
 205         ssize_t ret = 0;
 206         if (part_attr->show)
 207                 ret = part_attr->show(p,page);
 208         return ret;
 209 }
 210
 211 static struct sysfs_ops part_sysfs_ops = {
 212         .show   =       part_attr_show,
 213 };
 214
 215 static ssize_t part_dev_read(struct hd_struct * p, char *page)
 216 {
 217         struct gendisk *disk = container_of(p->kobj.parent,struct gendisk,kobj);
 218         dev_t dev = MKDEV(disk->major, disk->first_minor + p->partno);
 219         return print_dev_t(page, dev);
 220 }
 221 static ssize_t part_start_read(struct hd_struct * p, char *page)
 222 {
 223         return sprintf(page, "%llu\n",(unsigned long long)p->start_sect);
 224 }
 225 static ssize_t part_size_read(struct hd_struct * p, char *page)
 226 {
 227         return sprintf(page, "%llu\n",(unsigned long long)p->nr_sects);
 228 }
 229 static ssize_t part_stat_read(struct hd_struct * p, char *page)
 230 {
 231         return sprintf(page, "%8u %8llu %8u %8llu\n",
 232                        p->reads, (unsigned long long)p->read_sectors,
 233                        p->writes, (unsigned long long)p->write_sectors);
 234 }
 235 static struct part_attribute part_attr_dev = {
 236         .attr = {.name = "dev", .mode = S_IRUGO },
 237         .show   = part_dev_read
 238 };
 239 static struct part_attribute part_attr_start = {
 240         .attr = {.name = "start", .mode = S_IRUGO },
 241         .show   = part_start_read
 242 };
 243 static struct part_attribute part_attr_size = {
 244         .attr = {.name = "size", .mode = S_IRUGO },
 245         .show   = part_size_read
 246 };
 247 static struct part_attribute part_attr_stat = {
 248         .attr = {.name = "stat", .mode = S_IRUGO },
 249         .show   = part_stat_read
 250 };
 251
 252 static struct attribute * default_attrs[] = {
 253         &part_attr_dev.attr,
 254         &part_attr_start.attr,
 255         &part_attr_size.attr,
 256         &part_attr_stat.attr,
 257         NULL,
 258 };
 259
 260 extern struct subsystem block_subsys;
 261
 262 static void part_release(struct kobject *kobj)
 263 {
 264         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 265         kfree(p);
 266 }
 267
 268 struct kobj_type ktype_part = {
 269         .release        = part_release,
 270         .default_attrs  = default_attrs,
 271         .sysfs_ops      = &part_sysfs_ops,
 272 };
 273
 274 void delete_partition(struct gendisk *disk, int part)
 275 {
 276         struct hd_struct *p = disk->part[part-1];
 277         if (!p)
 278                 return;
 279         if (!p->nr_sects)
 280                 return;
 281         disk->part[part-1] = NULL;
 282         p->start_sect = 0;
 283         p->nr_sects = 0;
 284         p->reads = p->writes = p->read_sectors = p->write_sectors = 0;
 285         devfs_remove("%s/part%d", disk->devfs_name, part);
 286         kobject_unregister(&p->kobj);
 287 }
 288
 289 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len)
 290 {
 291         struct hd_struct *p;
 292
 293         p = kmalloc(sizeof(*p), GFP_KERNEL);
 294         if (!p)
 295                 return;
 296
 297         memset(p, 0, sizeof(*p));
 298         p->start_sect = start;
 299         p->nr_sects = len;
 300         p->partno = part;
 301
 302         devfs_mk_bdev(MKDEV(disk->major, disk->first_minor + part),
 303                         S_IFBLK|S_IRUSR|S_IWUSR,
 304                         "%s/part%d", disk->devfs_name, part);
 305
 306         if (isdigit(disk->kobj.name[strlen(disk->kobj.name)-1]))
 307                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%sp%d",disk->kobj.name,part);
 308         else
 309                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%s%d",disk->kobj.name,part);
 310         p->kobj.parent = &disk->kobj;
 311         p->kobj.ktype = &ktype_part;
 312         kobject_register(&p->kobj);
 313         disk->part[part-1] = p;
 314 }
 315
 316 static void disk_sysfs_symlinks(struct gendisk *disk)
 317 {
 318         struct device *target = get_device(disk->driverfs_dev);
 319         if (target) {
 320                 sysfs_create_link(&disk->kobj,&target->kobj,"device");
 321                 sysfs_create_link(&target->kobj,&disk->kobj,"block");
 322         }
 323 }
 324
 325 /* Not exported, helper to add_disk(). */
 326 void register_disk(struct gendisk *disk)
 327 {
 328         struct block_device *bdev;
 329         char *s;
 330         int err;
 331
 332         strlcpy(disk->kobj.name,disk->disk_name,KOBJ_NAME_LEN);
 333         /* ewww... some of these buggers have / in name... */
 334         s = strchr(disk->kobj.name, '/');
 335         if (s)
 336                 *s = '!';
 337         if ((err = kobject_add(&disk->kobj)))
 338                 return;
 339         disk_sysfs_symlinks(disk);
 340         kobject_hotplug(&disk->kobj, KOBJ_ADD);
 341
 342         /* No minors to use for partitions */
 343         if (disk->minors == 1) {
 344                 if (disk->devfs_name[0] != '\0')
 345                         devfs_add_disk(disk);
 346                 return;
 347         }
 348
 349         /* always add handle for the whole disk */
 350         devfs_add_partitioned(disk);
 351
 352         /* No such device (e.g., media were just removed) */
 353         if (!get_capacity(disk))
 354                 return;
 355
 356         bdev = bdget_disk(disk, 0);
 357         if (!bdev)
 358                 return;
 359
 360         bdev->bd_invalidated = 1;
 361         if (blkdev_get(bdev, FMODE_READ, 0) < 0)
 362                 return;
 363         blkdev_put(bdev);
 364 }
 365
 366 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 367 {
 368         struct parsed_partitions *state;
 369         int p, res;
 370
 371         if (bdev->bd_part_count)
 372                 return -EBUSY;
 373         res = invalidate_partition(disk, 0);
 374         if (res)
 375                 return res;
 376         bdev->bd_invalidated = 0;
 377         for (p = 1; p < disk->minors; p++)
 378                 delete_partition(disk, p);
 379         if (disk->fops->revalidate_disk)
 380                 disk->fops->revalidate_disk(disk);
 381         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 382                 return 0;
 383         for (p = 1; p < state->limit; p++) {
 384                 sector_t size = state->parts[p].size;
 385                 sector_t from = state->parts[p].from;
 386                 if (!size)
 387                         continue;
 388                 add_partition(disk, p, from, size);
 389 #ifdef CONFIG_BLK_DEV_MD
 390                 if (state->parts[p].flags)
 391                         md_autodetect_dev(bdev->bd_dev+p);
 392 #endif
 393         }
 394         kfree(state);
 395         return 0;
 396 }
 397
 398 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 399 {
 400         struct address_space *mapping = bdev->bd_inode->i_mapping;
 401         struct page *page;
 402
 403         page = read_cache_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 404                         (filler_t *)mapping->a_ops->readpage, NULL);
 405         if (!IS_ERR(page)) {
 406                 wait_on_page_locked(page);
 407                 if (!PageUptodate(page))
 408                         goto fail;
 409                 if (PageError(page))
 410                         goto fail;
 411                 p->v = page;
 412                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 413 fail:
 414                 page_cache_release(page);
 415         }
 416         p->v = NULL;
 417         return NULL;
 418 }
 419
 420 EXPORT_SYMBOL(read_dev_sector);
 421
 422 void del_gendisk(struct gendisk *disk)
 423 {
 424         int p;
 425
 426         /* invalidate stuff */
 427         for (p = disk->minors - 1; p > 0; p--) {
 428                 invalidate_partition(disk, p);
 429                 delete_partition(disk, p);
 430         }
 431         invalidate_partition(disk, 0);
 432         disk->capacity = 0;
 433         disk->flags &= ~GENHD_FL_UP;
 434         unlink_gendisk(disk);
 435         disk_stat_set_all(disk, 0);
 436         disk->stamp = disk->stamp_idle = 0;
 437
 438         devfs_remove_disk(disk);
 439
 440         if (disk->driverfs_dev) {
 441                 sysfs_remove_link(&disk->kobj, "device");
 442                 sysfs_remove_link(&disk->driverfs_dev->kobj, "block");
 443                 put_device(disk->driverfs_dev);
 444         }
 445         kobject_hotplug(&disk->kobj, KOBJ_REMOVE);
 446         kobject_del(&disk->kobj);
 447 }