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/genhd.h>
  22
  23 #include "check.h"
  24
  25 #include "acorn.h"
  26 #include "amiga.h"
  27 #include "atari.h"
  28 #include "ldm.h"
  29 #include "mac.h"
  30 #include "msdos.h"
  31 #include "osf.h"
  32 #include "sgi.h"
  33 #include "sun.h"
  34 #include "ibm.h"
  35 #include "ultrix.h"
  36 #include "efi.h"
  37 #include "karma.h"
  38 #include "sysv68.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 #ifdef CONFIG_SYSV68_PARTITION
 111         sysv68_partition,
 112 #endif
 113         NULL
 114 };
 115
 116 /*
 117  * disk_name() is used by partition check code and the genhd driver.
 118  * It formats the devicename of the indicated disk into
 119  * the supplied buffer (of size at least 32), and returns
 120  * a pointer to that same buffer (for convenience).
 121  */
 122
 123 char *disk_name(struct gendisk *hd, int part, char *buf)
 124 {
 125         if (!part)
 126                 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
 127         else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
 128                 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
 129         else
 130                 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);
 131
 132         return buf;
 133 }
 134
 135 const char *bdevname(struct block_device *bdev, char *buf)
 136 {
 137         int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
 138         return disk_name(bdev->bd_disk, part, buf);
 139 }
 140
 141 EXPORT_SYMBOL(bdevname);
 142
 143 /*
 144  * There's very little reason to use this, you should really
 145  * have a struct block_device just about everywhere and use
 146  * bdevname() instead.
 147  */
 148 const char *__bdevname(dev_t dev, char *buffer)
 149 {
 150         scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
 151                                 MAJOR(dev), MINOR(dev));
 152         return buffer;
 153 }
 154
 155 EXPORT_SYMBOL(__bdevname);
 156
 157 static struct parsed_partitions *
 158 check_partition(struct gendisk *hd, struct block_device *bdev)
 159 {
 160         struct parsed_partitions *state;
 161         int i, res, err;
 162
 163         state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 164         if (!state)
 165                 return NULL;
 166
 167         disk_name(hd, 0, state->name);
 168         printk(KERN_INFO " %s:", state->name);
 169         if (isdigit(state->name[strlen(state->name)-1]))
 170                 sprintf(state->name, "p");
 171
 172         state->limit = hd->minors;
 173         i = res = err = 0;
 174         while (!res && check_part[i]) {
 175                 memset(&state->parts, 0, sizeof(state->parts));
 176                 res = check_part[i++](state, bdev);
 177                 if (res < 0) {
 178                         /* We have hit an I/O error which we don't report now.
 179                         * But record it, and let the others do their job.
 180                         */
 181                         err = res;
 182                         res = 0;
 183                 }
 184
 185         }
 186         if (res > 0)
 187                 return state;
 188         if (err)
 189         /* The partition is unrecognized. So report I/O errors if there were any */
 190                 res = err;
 191         if (!res)
 192                 printk(" unknown partition table\n");
 193         else if (warn_no_part)
 194                 printk(" unable to read partition table\n");
 195         kfree(state);
 196         return ERR_PTR(res);
 197 }
 198
 199 static ssize_t part_start_show(struct device *dev,
 200                                struct device_attribute *attr, char *buf)
 201 {
 202         struct hd_struct *p = dev_to_part(dev);
 203
 204         return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
 205 }
 206
 207 static ssize_t part_size_show(struct device *dev,
 208                               struct device_attribute *attr, char *buf)
 209 {
 210         struct hd_struct *p = dev_to_part(dev);
 211         return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
 212 }
 213
 214 static ssize_t part_stat_show(struct device *dev,
 215                               struct device_attribute *attr, char *buf)
 216 {
 217         struct hd_struct *p = dev_to_part(dev);
 218
 219         preempt_disable();
 220         part_round_stats(p);
 221         preempt_enable();
 222         return sprintf(buf,
 223                 "%8lu %8lu %8llu %8u "
 224                 "%8lu %8lu %8llu %8u "
 225                 "%8u %8u %8u"
 226                 "\n",
 227                 part_stat_read(p, ios[READ]),
 228                 part_stat_read(p, merges[READ]),
 229                 (unsigned long long)part_stat_read(p, sectors[READ]),
 230                 jiffies_to_msecs(part_stat_read(p, ticks[READ])),
 231                 part_stat_read(p, ios[WRITE]),
 232                 part_stat_read(p, merges[WRITE]),
 233                 (unsigned long long)part_stat_read(p, sectors[WRITE]),
 234                 jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
 235                 p->in_flight,
 236                 jiffies_to_msecs(part_stat_read(p, io_ticks)),
 237                 jiffies_to_msecs(part_stat_read(p, time_in_queue)));
 238 }
 239
 240 #ifdef CONFIG_FAIL_MAKE_REQUEST
 241 static ssize_t part_fail_show(struct device *dev,
 242                               struct device_attribute *attr, char *buf)
 243 {
 244         struct hd_struct *p = dev_to_part(dev);
 245
 246         return sprintf(buf, "%d\n", p->make_it_fail);
 247 }
 248
 249 static ssize_t part_fail_store(struct device *dev,
 250                                struct device_attribute *attr,
 251                                const char *buf, size_t count)
 252 {
 253         struct hd_struct *p = dev_to_part(dev);
 254         int i;
 255
 256         if (count > 0 && sscanf(buf, "%d", &i) > 0)
 257                 p->make_it_fail = (i == 0) ? 0 : 1;
 258
 259         return count;
 260 }
 261 #endif
 262
 263 static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
 264 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
 265 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
 266 #ifdef CONFIG_FAIL_MAKE_REQUEST
 267 static struct device_attribute dev_attr_fail =
 268         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
 269 #endif
 270
 271 static struct attribute *part_attrs[] = {
 272         &dev_attr_start.attr,
 273         &dev_attr_size.attr,
 274         &dev_attr_stat.attr,
 275 #ifdef CONFIG_FAIL_MAKE_REQUEST
 276         &dev_attr_fail.attr,
 277 #endif
 278         NULL
 279 };
 280
 281 static struct attribute_group part_attr_group = {
 282         .attrs = part_attrs,
 283 };
 284
 285 static struct attribute_group *part_attr_groups[] = {
 286         &part_attr_group,
 287         NULL
 288 };
 289
 290 static void part_release(struct device *dev)
 291 {
 292         struct hd_struct *p = dev_to_part(dev);
 293         free_part_stats(p);
 294         kfree(p);
 295 }
 296
 297 struct device_type part_type = {
 298         .name           = "partition",
 299         .groups         = part_attr_groups,
 300         .release        = part_release,
 301 };
 302
 303 static inline void partition_sysfs_add_subdir(struct hd_struct *p)
 304 {
 305         struct kobject *k;
 306
 307         k = kobject_get(&p->dev.kobj);
 308         p->holder_dir = kobject_create_and_add("holders", k);
 309         kobject_put(k);
 310 }
 311
 312 static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
 313 {
 314         struct kobject *k;
 315
 316         k = kobject_get(&disk->dev.kobj);
 317         disk->holder_dir = kobject_create_and_add("holders", k);
 318         disk->slave_dir = kobject_create_and_add("slaves", k);
 319         kobject_put(k);
 320 }
 321
 322 void delete_partition(struct gendisk *disk, int part)
 323 {
 324         struct hd_struct *p = disk->part[part-1];
 325
 326         if (!p)
 327                 return;
 328         if (!p->nr_sects)
 329                 return;
 330         disk->part[part-1] = NULL;
 331         p->start_sect = 0;
 332         p->nr_sects = 0;
 333         part_stat_set_all(p, 0);
 334         kobject_put(p->holder_dir);
 335         device_del(&p->dev);
 336         put_device(&p->dev);
 337 }
 338
 339 static ssize_t whole_disk_show(struct device *dev,
 340                                struct device_attribute *attr, char *buf)
 341 {
 342         return 0;
 343 }
 344 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
 345                    whole_disk_show, NULL);
 346
 347 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
 348 {
 349         struct hd_struct *p;
 350         int err;
 351
 352         p = kzalloc(sizeof(*p), GFP_KERNEL);
 353         if (!p)
 354                 return;
 355
 356         if (!init_part_stats(p)) {
 357                 kfree(p);
 358                 return;
 359         }
 360         p->start_sect = start;
 361         p->nr_sects = len;
 362         p->partno = part;
 363         p->policy = disk->policy;
 364
 365         if (isdigit(disk->dev.bus_id[strlen(disk->dev.bus_id)-1]))
 366                 snprintf(p->dev.bus_id, BUS_ID_SIZE,
 367                 "%sp%d", disk->dev.bus_id, part);
 368         else
 369                 snprintf(p->dev.bus_id, BUS_ID_SIZE,
 370                          "%s%d", disk->dev.bus_id, part);
 371
 372         device_initialize(&p->dev);
 373         p->dev.devt = MKDEV(disk->major, disk->first_minor + part);
 374         p->dev.class = &block_class;
 375         p->dev.type = &part_type;
 376         p->dev.parent = &disk->dev;
 377         disk->part[part-1] = p;
 378
 379         /* delay uevent until 'holders' subdir is created */
 380         p->dev.uevent_suppress = 1;
 381         device_add(&p->dev);
 382         partition_sysfs_add_subdir(p);
 383         p->dev.uevent_suppress = 0;
 384         if (flags & ADDPART_FLAG_WHOLEDISK)
 385                 err = device_create_file(&p->dev, &dev_attr_whole_disk);
 386
 387         /* suppress uevent if the disk supresses it */
 388         if (!disk->dev.uevent_suppress)
 389                 kobject_uevent(&p->dev.kobj, KOBJ_ADD);
 390 }
 391
 392 /* Not exported, helper to add_disk(). */
 393 void register_disk(struct gendisk *disk)
 394 {
 395         struct block_device *bdev;
 396         char *s;
 397         int i;
 398         struct hd_struct *p;
 399         int err;
 400
 401         disk->dev.parent = disk->driverfs_dev;
 402         disk->dev.devt = MKDEV(disk->major, disk->first_minor);
 403
 404         strlcpy(disk->dev.bus_id, disk->disk_name, BUS_ID_SIZE);
 405         /* ewww... some of these buggers have / in the name... */
 406         s = strchr(disk->dev.bus_id, '/');
 407         if (s)
 408                 *s = '!';
 409
 410         /* delay uevents, until we scanned partition table */
 411         disk->dev.uevent_suppress = 1;
 412
 413         if (device_add(&disk->dev))
 414                 return;
 415 #ifndef CONFIG_SYSFS_DEPRECATED
 416         err = sysfs_create_link(block_depr, &disk->dev.kobj,
 417                                 kobject_name(&disk->dev.kobj));
 418         if (err) {
 419                 device_del(&disk->dev);
 420                 return;
 421         }
 422 #endif
 423         disk_sysfs_add_subdirs(disk);
 424
 425         /* No minors to use for partitions */
 426         if (disk->minors == 1)
 427                 goto exit;
 428
 429         /* No such device (e.g., media were just removed) */
 430         if (!get_capacity(disk))
 431                 goto exit;
 432
 433         bdev = bdget_disk(disk, 0);
 434         if (!bdev)
 435                 goto exit;
 436
 437         bdev->bd_invalidated = 1;
 438         err = blkdev_get(bdev, FMODE_READ, 0);
 439         if (err < 0)
 440                 goto exit;
 441         blkdev_put(bdev);
 442
 443 exit:
 444         /* announce disk after possible partitions are created */
 445         disk->dev.uevent_suppress = 0;
 446         kobject_uevent(&disk->dev.kobj, KOBJ_ADD);
 447
 448         /* announce possible partitions */
 449         for (i = 1; i < disk->minors; i++) {
 450                 p = disk->part[i-1];
 451                 if (!p || !p->nr_sects)
 452                         continue;
 453                 kobject_uevent(&p->dev.kobj, KOBJ_ADD);
 454         }
 455 }
 456
 457 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 458 {
 459         struct parsed_partitions *state;
 460         int p, res;
 461
 462         if (bdev->bd_part_count)
 463                 return -EBUSY;
 464         res = invalidate_partition(disk, 0);
 465         if (res)
 466                 return res;
 467         bdev->bd_invalidated = 0;
 468         for (p = 1; p < disk->minors; p++)
 469                 delete_partition(disk, p);
 470         if (disk->fops->revalidate_disk)
 471                 disk->fops->revalidate_disk(disk);
 472         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 473                 return 0;
 474         if (IS_ERR(state))      /* I/O error reading the partition table */
 475                 return -EIO;
 476
 477         /* tell userspace that the media / partition table may have changed */
 478         kobject_uevent(&disk->dev.kobj, KOBJ_CHANGE);
 479
 480         for (p = 1; p < state->limit; p++) {
 481                 sector_t size = state->parts[p].size;
 482                 sector_t from = state->parts[p].from;
 483                 if (!size)
 484                         continue;
 485                 if (from + size > get_capacity(disk)) {
 486                         printk(" %s: p%d exceeds device capacity\n",
 487                                 disk->disk_name, p);
 488                 }
 489                 add_partition(disk, p, from, size, state->parts[p].flags);
 490 #ifdef CONFIG_BLK_DEV_MD
 491                 if (state->parts[p].flags & ADDPART_FLAG_RAID)
 492                         md_autodetect_dev(bdev->bd_dev+p);
 493 #endif
 494         }
 495         kfree(state);
 496         return 0;
 497 }
 498
 499 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 500 {
 501         struct address_space *mapping = bdev->bd_inode->i_mapping;
 502         struct page *page;
 503
 504         page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 505                                  NULL);
 506         if (!IS_ERR(page)) {
 507                 if (PageError(page))
 508                         goto fail;
 509                 p->v = page;
 510                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 511 fail:
 512                 page_cache_release(page);
 513         }
 514         p->v = NULL;
 515         return NULL;
 516 }
 517
 518 EXPORT_SYMBOL(read_dev_sector);
 519
 520 void del_gendisk(struct gendisk *disk)
 521 {
 522         int p;
 523
 524         /* invalidate stuff */
 525         for (p = disk->minors - 1; p > 0; p--) {
 526                 invalidate_partition(disk, p);
 527                 delete_partition(disk, p);
 528         }
 529         invalidate_partition(disk, 0);
 530         disk->capacity = 0;
 531         disk->flags &= ~GENHD_FL_UP;
 532         unlink_gendisk(disk);
 533         disk_stat_set_all(disk, 0);
 534         disk->stamp = 0;
 535
 536         kobject_put(disk->holder_dir);
 537         kobject_put(disk->slave_dir);
 538         disk->driverfs_dev = NULL;
 539 #ifndef CONFIG_SYSFS_DEPRECATED
 540         sysfs_remove_link(block_depr, disk->dev.bus_id);
 541 #endif
 542         device_del(&disk->dev);
 543 }