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 #include "sysv68.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_MSDOS_PARTITION
  83         msdos_partition,
  84 #endif
  85 #ifdef CONFIG_OSF_PARTITION
  86         osf_partition,
  87 #endif
  88 #ifdef CONFIG_SUN_PARTITION
  89         sun_partition,
  90 #endif
  91 #ifdef CONFIG_AMIGA_PARTITION
  92         amiga_partition,
  93 #endif
  94 #ifdef CONFIG_ATARI_PARTITION
  95         atari_partition,
  96 #endif
  97 #ifdef CONFIG_MAC_PARTITION
  98         mac_partition,
  99 #endif
 100 #ifdef CONFIG_ULTRIX_PARTITION
 101         ultrix_partition,
 102 #endif
 103 #ifdef CONFIG_IBM_PARTITION
 104         ibm_partition,
 105 #endif
 106 #ifdef CONFIG_KARMA_PARTITION
 107         karma_partition,
 108 #endif
 109 #ifdef CONFIG_SYSV68_PARTITION
 110         sysv68_partition,
 111 #endif
 112         NULL
 113 };
 114
 115 /*
 116  * disk_name() is used by partition check code and the genhd driver.
 117  * It formats the devicename of the indicated disk into
 118  * the supplied buffer (of size at least 32), and returns
 119  * a pointer to that same buffer (for convenience).
 120  */
 121
 122 char *disk_name(struct gendisk *hd, int part, char *buf)
 123 {
 124         if (!part)
 125                 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
 126         else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
 127                 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
 128         else
 129                 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);
 130
 131         return buf;
 132 }
 133
 134 const char *bdevname(struct block_device *bdev, char *buf)
 135 {
 136         int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
 137         return disk_name(bdev->bd_disk, part, buf);
 138 }
 139
 140 EXPORT_SYMBOL(bdevname);
 141
 142 /*
 143  * There's very little reason to use this, you should really
 144  * have a struct block_device just about everywhere and use
 145  * bdevname() instead.
 146  */
 147 const char *__bdevname(dev_t dev, char *buffer)
 148 {
 149         scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
 150                                 MAJOR(dev), MINOR(dev));
 151         return buffer;
 152 }
 153
 154 EXPORT_SYMBOL(__bdevname);
 155
 156 static struct parsed_partitions *
 157 check_partition(struct gendisk *hd, struct block_device *bdev)
 158 {
 159         struct parsed_partitions *state;
 160         int i, res, err;
 161
 162         state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 163         if (!state)
 164                 return NULL;
 165
 166         disk_name(hd, 0, state->name);
 167         printk(KERN_INFO " %s:", state->name);
 168         if (isdigit(state->name[strlen(state->name)-1]))
 169                 sprintf(state->name, "p");
 170
 171         state->limit = hd->minors;
 172         i = res = err = 0;
 173         while (!res && check_part[i]) {
 174                 memset(&state->parts, 0, sizeof(state->parts));
 175                 res = check_part[i++](state, bdev);
 176                 if (res < 0) {
 177                         /* We have hit an I/O error which we don't report now.
 178                         * But record it, and let the others do their job.
 179                         */
 180                         err = res;
 181                         res = 0;
 182                 }
 183
 184         }
 185         if (res > 0)
 186                 return state;
 187         if (err)
 188         /* The partition is unrecognized. So report I/O errors if there were any */
 189                 res = err;
 190         if (!res)
 191                 printk(" unknown partition table\n");
 192         else if (warn_no_part)
 193                 printk(" unable to read partition table\n");
 194         kfree(state);
 195         return ERR_PTR(res);
 196 }
 197
 198 static ssize_t part_start_show(struct device *dev,
 199                                struct device_attribute *attr, char *buf)
 200 {
 201         struct hd_struct *p = dev_to_part(dev);
 202
 203         return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
 204 }
 205
 206 static ssize_t part_size_show(struct device *dev,
 207                               struct device_attribute *attr, char *buf)
 208 {
 209         struct hd_struct *p = dev_to_part(dev);
 210         return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
 211 }
 212
 213 static ssize_t part_stat_show(struct device *dev,
 214                               struct device_attribute *attr, char *buf)
 215 {
 216         struct hd_struct *p = dev_to_part(dev);
 217
 218         return sprintf(buf, "%8u %8llu %8u %8llu\n",
 219                        p->ios[0], (unsigned long long)p->sectors[0],
 220                        p->ios[1], (unsigned long long)p->sectors[1]);
 221 }
 222
 223 #ifdef CONFIG_FAIL_MAKE_REQUEST
 224 static ssize_t part_fail_show(struct device *dev,
 225                               struct device_attribute *attr, char *buf)
 226 {
 227         struct hd_struct *p = dev_to_part(dev);
 228
 229         return sprintf(buf, "%d\n", p->make_it_fail);
 230 }
 231
 232 static ssize_t part_fail_store(struct device *dev,
 233                                struct device_attribute *attr,
 234                                const char *buf, size_t count)
 235 {
 236         struct hd_struct *p = dev_to_part(dev);
 237         int i;
 238
 239         if (count > 0 && sscanf(buf, "%d", &i) > 0)
 240                 p->make_it_fail = (i == 0) ? 0 : 1;
 241
 242         return count;
 243 }
 244 #endif
 245
 246 static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
 247 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
 248 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
 249 #ifdef CONFIG_FAIL_MAKE_REQUEST
 250 static struct device_attribute dev_attr_fail =
 251         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
 252 #endif
 253
 254 static struct attribute *part_attrs[] = {
 255         &dev_attr_start.attr,
 256         &dev_attr_size.attr,
 257         &dev_attr_stat.attr,
 258 #ifdef CONFIG_FAIL_MAKE_REQUEST
 259         &dev_attr_fail.attr,
 260 #endif
 261         NULL
 262 };
 263
 264 static struct attribute_group part_attr_group = {
 265         .attrs = part_attrs,
 266 };
 267
 268 static struct attribute_group *part_attr_groups[] = {
 269         &part_attr_group,
 270         NULL
 271 };
 272
 273 static void part_release(struct device *dev)
 274 {
 275         struct hd_struct *p = dev_to_part(dev);
 276         kfree(p);
 277 }
 278
 279 struct device_type part_type = {
 280         .name           = "partition",
 281         .groups         = part_attr_groups,
 282         .release        = part_release,
 283 };
 284
 285 static inline void partition_sysfs_add_subdir(struct hd_struct *p)
 286 {
 287         struct kobject *k;
 288
 289         k = kobject_get(&p->dev.kobj);
 290         p->holder_dir = kobject_create_and_add("holders", k);
 291         kobject_put(k);
 292 }
 293
 294 static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
 295 {
 296         struct kobject *k;
 297
 298         k = kobject_get(&disk->dev.kobj);
 299         disk->holder_dir = kobject_create_and_add("holders", k);
 300         disk->slave_dir = kobject_create_and_add("slaves", k);
 301         kobject_put(k);
 302 }
 303
 304 void delete_partition(struct gendisk *disk, int part)
 305 {
 306         struct hd_struct *p = disk->part[part-1];
 307
 308         if (!p)
 309                 return;
 310         if (!p->nr_sects)
 311                 return;
 312         disk->part[part-1] = NULL;
 313         p->start_sect = 0;
 314         p->nr_sects = 0;
 315         p->ios[0] = p->ios[1] = 0;
 316         p->sectors[0] = p->sectors[1] = 0;
 317         kobject_put(p->holder_dir);
 318         device_del(&p->dev);
 319         put_device(&p->dev);
 320 }
 321
 322 static ssize_t whole_disk_show(struct device *dev,
 323                                struct device_attribute *attr, char *buf)
 324 {
 325         return 0;
 326 }
 327 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
 328                    whole_disk_show, NULL);
 329
 330 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
 331 {
 332         struct hd_struct *p;
 333         int err;
 334
 335         p = kzalloc(sizeof(*p), GFP_KERNEL);
 336         if (!p)
 337                 return;
 338
 339         p->start_sect = start;
 340         p->nr_sects = len;
 341         p->partno = part;
 342         p->policy = disk->policy;
 343
 344         if (isdigit(disk->dev.bus_id[strlen(disk->dev.bus_id)-1]))
 345                 snprintf(p->dev.bus_id, BUS_ID_SIZE,
 346                 "%sp%d", disk->dev.bus_id, part);
 347         else
 348                 snprintf(p->dev.bus_id, BUS_ID_SIZE,
 349                          "%s%d", disk->dev.bus_id, part);
 350
 351         device_initialize(&p->dev);
 352         p->dev.devt = MKDEV(disk->major, disk->first_minor + part);
 353         p->dev.class = &block_class;
 354         p->dev.type = &part_type;
 355         p->dev.parent = &disk->dev;
 356         disk->part[part-1] = p;
 357
 358         /* delay uevent until 'holders' subdir is created */
 359         p->dev.uevent_suppress = 1;
 360         device_add(&p->dev);
 361         partition_sysfs_add_subdir(p);
 362         p->dev.uevent_suppress = 0;
 363         if (flags & ADDPART_FLAG_WHOLEDISK)
 364                 err = device_create_file(&p->dev, &dev_attr_whole_disk);
 365
 366         /* suppress uevent if the disk supresses it */
 367         if (!disk->dev.uevent_suppress)
 368                 kobject_uevent(&p->dev.kobj, KOBJ_ADD);
 369 }
 370
 371 /* Not exported, helper to add_disk(). */
 372 void register_disk(struct gendisk *disk)
 373 {
 374         struct block_device *bdev;
 375         char *s;
 376         int i;
 377         struct hd_struct *p;
 378         int err;
 379
 380         disk->dev.parent = disk->driverfs_dev;
 381         disk->dev.devt = MKDEV(disk->major, disk->first_minor);
 382
 383         strlcpy(disk->dev.bus_id, disk->disk_name, KOBJ_NAME_LEN);
 384         /* ewww... some of these buggers have / in the name... */
 385         s = strchr(disk->dev.bus_id, '/');
 386         if (s)
 387                 *s = '!';
 388
 389         /* delay uevents, until we scanned partition table */
 390         disk->dev.uevent_suppress = 1;
 391
 392         if (device_add(&disk->dev))
 393                 return;
 394 #ifndef CONFIG_SYSFS_DEPRECATED
 395         err = sysfs_create_link(block_depr, &disk->dev.kobj,
 396                                 kobject_name(&disk->dev.kobj));
 397         if (err) {
 398                 device_del(&disk->dev);
 399                 return;
 400         }
 401 #endif
 402         disk_sysfs_add_subdirs(disk);
 403
 404         /* No minors to use for partitions */
 405         if (disk->minors == 1)
 406                 goto exit;
 407
 408         /* No such device (e.g., media were just removed) */
 409         if (!get_capacity(disk))
 410                 goto exit;
 411
 412         bdev = bdget_disk(disk, 0);
 413         if (!bdev)
 414                 goto exit;
 415
 416         bdev->bd_invalidated = 1;
 417         err = blkdev_get(bdev, FMODE_READ, 0);
 418         if (err < 0)
 419                 goto exit;
 420         blkdev_put(bdev);
 421
 422 exit:
 423         /* announce disk after possible partitions are created */
 424         disk->dev.uevent_suppress = 0;
 425         kobject_uevent(&disk->dev.kobj, KOBJ_ADD);
 426
 427         /* announce possible partitions */
 428         for (i = 1; i < disk->minors; i++) {
 429                 p = disk->part[i-1];
 430                 if (!p || !p->nr_sects)
 431                         continue;
 432                 kobject_uevent(&p->dev.kobj, KOBJ_ADD);
 433         }
 434 }
 435
 436 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 437 {
 438         struct parsed_partitions *state;
 439         int p, res;
 440
 441         if (bdev->bd_part_count)
 442                 return -EBUSY;
 443         res = invalidate_partition(disk, 0);
 444         if (res)
 445                 return res;
 446         bdev->bd_invalidated = 0;
 447         for (p = 1; p < disk->minors; p++)
 448                 delete_partition(disk, p);
 449         if (disk->fops->revalidate_disk)
 450                 disk->fops->revalidate_disk(disk);
 451         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 452                 return 0;
 453         if (IS_ERR(state))      /* I/O error reading the partition table */
 454                 return -EIO;
 455         for (p = 1; p < state->limit; p++) {
 456                 sector_t size = state->parts[p].size;
 457                 sector_t from = state->parts[p].from;
 458                 if (!size)
 459                         continue;
 460                 if (from + size > get_capacity(disk)) {
 461                         printk(" %s: p%d exceeds device capacity\n",
 462                                 disk->disk_name, p);
 463                 }
 464                 add_partition(disk, p, from, size, state->parts[p].flags);
 465 #ifdef CONFIG_BLK_DEV_MD
 466                 if (state->parts[p].flags & ADDPART_FLAG_RAID)
 467                         md_autodetect_dev(bdev->bd_dev+p);
 468 #endif
 469         }
 470         kfree(state);
 471         return 0;
 472 }
 473
 474 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 475 {
 476         struct address_space *mapping = bdev->bd_inode->i_mapping;
 477         struct page *page;
 478
 479         page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 480                                  NULL);
 481         if (!IS_ERR(page)) {
 482                 if (PageError(page))
 483                         goto fail;
 484                 p->v = page;
 485                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 486 fail:
 487                 page_cache_release(page);
 488         }
 489         p->v = NULL;
 490         return NULL;
 491 }
 492
 493 EXPORT_SYMBOL(read_dev_sector);
 494
 495 void del_gendisk(struct gendisk *disk)
 496 {
 497         int p;
 498
 499         /* invalidate stuff */
 500         for (p = disk->minors - 1; p > 0; p--) {
 501                 invalidate_partition(disk, p);
 502                 delete_partition(disk, p);
 503         }
 504         invalidate_partition(disk, 0);
 505         disk->capacity = 0;
 506         disk->flags &= ~GENHD_FL_UP;
 507         unlink_gendisk(disk);
 508         disk_stat_set_all(disk, 0);
 509         disk->stamp = 0;
 510
 511         kobject_put(disk->holder_dir);
 512         kobject_put(disk->slave_dir);
 513         disk->driverfs_dev = NULL;
 514 #ifndef CONFIG_SYSFS_DEPRECATED
 515         sysfs_remove_link(block_depr, disk->dev.bus_id);
 516 #endif
 517         device_del(&disk->dev);
 518 }