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 partno, char *buf)
 124 {
 125         if (!partno)
 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, partno);
 129         else
 130                 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
 131
 132         return buf;
 133 }
 134
 135 const char *bdevname(struct block_device *bdev, char *buf)
 136 {
 137         int partno = 0;
 138
 139         if (bdev->bd_part)
 140                 partno = bdev->bd_part->partno;
 141
 142         return disk_name(bdev->bd_disk, partno, buf);
 143 }
 144
 145 EXPORT_SYMBOL(bdevname);
 146
 147 /*
 148  * There's very little reason to use this, you should really
 149  * have a struct block_device just about everywhere and use
 150  * bdevname() instead.
 151  */
 152 const char *__bdevname(dev_t dev, char *buffer)
 153 {
 154         scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
 155                                 MAJOR(dev), MINOR(dev));
 156         return buffer;
 157 }
 158
 159 EXPORT_SYMBOL(__bdevname);
 160
 161 static struct parsed_partitions *
 162 check_partition(struct gendisk *hd, struct block_device *bdev)
 163 {
 164         struct parsed_partitions *state;
 165         int i, res, err;
 166
 167         state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 168         if (!state)
 169                 return NULL;
 170
 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 = disk_max_parts(hd);
 177         i = res = err = 0;
 178         while (!res && check_part[i]) {
 179                 memset(&state->parts, 0, sizeof(state->parts));
 180                 res = check_part[i++](state, bdev);
 181                 if (res < 0) {
 182                         /* We have hit an I/O error which we don't report now.
 183                         * But record it, and let the others do their job.
 184                         */
 185                         err = res;
 186                         res = 0;
 187                 }
 188
 189         }
 190         if (res > 0)
 191                 return state;
 192         if (err)
 193         /* The partition is unrecognized. So report I/O errors if there were any */
 194                 res = err;
 195         if (!res)
 196                 printk(" unknown partition table\n");
 197         else if (warn_no_part)
 198                 printk(" unable to read partition table\n");
 199         kfree(state);
 200         return ERR_PTR(res);
 201 }
 202
 203 static ssize_t part_start_show(struct device *dev,
 204                                struct device_attribute *attr, char *buf)
 205 {
 206         struct hd_struct *p = dev_to_part(dev);
 207
 208         return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
 209 }
 210
 211 ssize_t part_size_show(struct device *dev,
 212                        struct device_attribute *attr, char *buf)
 213 {
 214         struct hd_struct *p = dev_to_part(dev);
 215         return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
 216 }
 217
 218 static ssize_t part_stat_show(struct device *dev,
 219                               struct device_attribute *attr, char *buf)
 220 {
 221         struct hd_struct *p = dev_to_part(dev);
 222         int cpu;
 223
 224         cpu = disk_stat_lock();
 225         part_round_stats(cpu, p);
 226         disk_stat_unlock();
 227         return sprintf(buf,
 228                 "%8lu %8lu %8llu %8u "
 229                 "%8lu %8lu %8llu %8u "
 230                 "%8u %8u %8u"
 231                 "\n",
 232                 part_stat_read(p, ios[READ]),
 233                 part_stat_read(p, merges[READ]),
 234                 (unsigned long long)part_stat_read(p, sectors[READ]),
 235                 jiffies_to_msecs(part_stat_read(p, ticks[READ])),
 236                 part_stat_read(p, ios[WRITE]),
 237                 part_stat_read(p, merges[WRITE]),
 238                 (unsigned long long)part_stat_read(p, sectors[WRITE]),
 239                 jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
 240                 p->in_flight,
 241                 jiffies_to_msecs(part_stat_read(p, io_ticks)),
 242                 jiffies_to_msecs(part_stat_read(p, time_in_queue)));
 243 }
 244
 245 #ifdef CONFIG_FAIL_MAKE_REQUEST
 246 static ssize_t part_fail_show(struct device *dev,
 247                               struct device_attribute *attr, char *buf)
 248 {
 249         struct hd_struct *p = dev_to_part(dev);
 250
 251         return sprintf(buf, "%d\n", p->make_it_fail);
 252 }
 253
 254 static ssize_t part_fail_store(struct device *dev,
 255                                struct device_attribute *attr,
 256                                const char *buf, size_t count)
 257 {
 258         struct hd_struct *p = dev_to_part(dev);
 259         int i;
 260
 261         if (count > 0 && sscanf(buf, "%d", &i) > 0)
 262                 p->make_it_fail = (i == 0) ? 0 : 1;
 263
 264         return count;
 265 }
 266 #endif
 267
 268 static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
 269 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
 270 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
 271 #ifdef CONFIG_FAIL_MAKE_REQUEST
 272 static struct device_attribute dev_attr_fail =
 273         __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
 274 #endif
 275
 276 static struct attribute *part_attrs[] = {
 277         &dev_attr_start.attr,
 278         &dev_attr_size.attr,
 279         &dev_attr_stat.attr,
 280 #ifdef CONFIG_FAIL_MAKE_REQUEST
 281         &dev_attr_fail.attr,
 282 #endif
 283         NULL
 284 };
 285
 286 static struct attribute_group part_attr_group = {
 287         .attrs = part_attrs,
 288 };
 289
 290 static struct attribute_group *part_attr_groups[] = {
 291         &part_attr_group,
 292         NULL
 293 };
 294
 295 static void part_release(struct device *dev)
 296 {
 297         struct hd_struct *p = dev_to_part(dev);
 298         free_part_stats(p);
 299         kfree(p);
 300 }
 301
 302 struct device_type part_type = {
 303         .name           = "partition",
 304         .groups         = part_attr_groups,
 305         .release        = part_release,
 306 };
 307
 308 static void delete_partition_rcu_cb(struct rcu_head *head)
 309 {
 310         struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
 311
 312         part->start_sect = 0;
 313         part->nr_sects = 0;
 314         part_stat_set_all(part, 0);
 315         put_device(part_to_dev(part));
 316 }
 317
 318 void delete_partition(struct gendisk *disk, int partno)
 319 {
 320         struct hd_struct *part;
 321
 322         part = disk->__part[partno];
 323         if (!part)
 324                 return;
 325
 326         blk_free_devt(part_devt(part));
 327         rcu_assign_pointer(disk->__part[partno], NULL);
 328         kobject_put(part->holder_dir);
 329         device_del(part_to_dev(part));
 330
 331         call_rcu(&part->rcu_head, delete_partition_rcu_cb);
 332 }
 333
 334 static ssize_t whole_disk_show(struct device *dev,
 335                                struct device_attribute *attr, char *buf)
 336 {
 337         return 0;
 338 }
 339 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
 340                    whole_disk_show, NULL);
 341
 342 int add_partition(struct gendisk *disk, int partno,
 343                   sector_t start, sector_t len, int flags)
 344 {
 345         struct hd_struct *p;
 346         dev_t devt = MKDEV(0, 0);
 347         struct device *ddev = disk_to_dev(disk);
 348         struct device *pdev;
 349         const char *dname;
 350         int err;
 351
 352         if (disk->__part[partno])
 353                 return -EBUSY;
 354
 355         p = kzalloc(sizeof(*p), GFP_KERNEL);
 356         if (!p)
 357                 return -ENOMEM;
 358
 359         if (!init_part_stats(p)) {
 360                 err = -ENOMEM;
 361                 goto out_free;
 362         }
 363         pdev = part_to_dev(p);
 364
 365         p->start_sect = start;
 366         p->nr_sects = len;
 367         p->partno = partno;
 368         p->policy = get_disk_ro(disk);
 369
 370         dname = dev_name(ddev);
 371         if (isdigit(dname[strlen(dname) - 1]))
 372                 snprintf(pdev->bus_id, BUS_ID_SIZE, "%sp%d", dname, partno);
 373         else
 374                 snprintf(pdev->bus_id, BUS_ID_SIZE, "%s%d", dname, partno);
 375
 376         device_initialize(pdev);
 377         pdev->class = &block_class;
 378         pdev->type = &part_type;
 379         pdev->parent = ddev;
 380
 381         err = blk_alloc_devt(p, &devt);
 382         if (err)
 383                 goto out_free;
 384         pdev->devt = devt;
 385
 386         /* delay uevent until 'holders' subdir is created */
 387         pdev->uevent_suppress = 1;
 388         err = device_add(pdev);
 389         if (err)
 390                 goto out_put;
 391
 392         err = -ENOMEM;
 393         p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
 394         if (!p->holder_dir)
 395                 goto out_del;
 396
 397         pdev->uevent_suppress = 0;
 398         if (flags & ADDPART_FLAG_WHOLEDISK) {
 399                 err = device_create_file(pdev, &dev_attr_whole_disk);
 400                 if (err)
 401                         goto out_del;
 402         }
 403
 404         /* everything is up and running, commence */
 405         INIT_RCU_HEAD(&p->rcu_head);
 406         rcu_assign_pointer(disk->__part[partno], p);
 407
 408         /* suppress uevent if the disk supresses it */
 409         if (!ddev->uevent_suppress)
 410                 kobject_uevent(&pdev->kobj, KOBJ_ADD);
 411
 412         return 0;
 413
 414 out_free:
 415         kfree(p);
 416         return err;
 417 out_del:
 418         kobject_put(p->holder_dir);
 419         device_del(pdev);
 420 out_put:
 421         put_device(pdev);
 422         blk_free_devt(devt);
 423         return err;
 424 }
 425
 426 /* Not exported, helper to add_disk(). */
 427 void register_disk(struct gendisk *disk)
 428 {
 429         struct device *ddev = disk_to_dev(disk);
 430         struct block_device *bdev;
 431         struct disk_part_iter piter;
 432         struct hd_struct *part;
 433         char *s;
 434         int err;
 435
 436         ddev->parent = disk->driverfs_dev;
 437
 438         strlcpy(ddev->bus_id, disk->disk_name, BUS_ID_SIZE);
 439         /* ewww... some of these buggers have / in the name... */
 440         s = strchr(ddev->bus_id, '/');
 441         if (s)
 442                 *s = '!';
 443
 444         /* delay uevents, until we scanned partition table */
 445         ddev->uevent_suppress = 1;
 446
 447         if (device_add(ddev))
 448                 return;
 449 #ifndef CONFIG_SYSFS_DEPRECATED
 450         err = sysfs_create_link(block_depr, &ddev->kobj,
 451                                 kobject_name(&ddev->kobj));
 452         if (err) {
 453                 device_del(ddev);
 454                 return;
 455         }
 456 #endif
 457         disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
 458         disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
 459
 460         /* No minors to use for partitions */
 461         if (!disk_partitionable(disk))
 462                 goto exit;
 463
 464         /* No such device (e.g., media were just removed) */
 465         if (!get_capacity(disk))
 466                 goto exit;
 467
 468         bdev = bdget_disk(disk, 0);
 469         if (!bdev)
 470                 goto exit;
 471
 472         bdev->bd_invalidated = 1;
 473         err = blkdev_get(bdev, FMODE_READ, 0);
 474         if (err < 0)
 475                 goto exit;
 476         blkdev_put(bdev);
 477
 478 exit:
 479         /* announce disk after possible partitions are created */
 480         ddev->uevent_suppress = 0;
 481         kobject_uevent(&ddev->kobj, KOBJ_ADD);
 482
 483         /* announce possible partitions */
 484         disk_part_iter_init(&piter, disk, 0);
 485         while ((part = disk_part_iter_next(&piter)))
 486                 kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
 487         disk_part_iter_exit(&piter);
 488 }
 489
 490 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 491 {
 492         struct disk_part_iter piter;
 493         struct hd_struct *part;
 494         struct parsed_partitions *state;
 495         int p, res;
 496
 497         if (bdev->bd_part_count)
 498                 return -EBUSY;
 499         res = invalidate_partition(disk, 0);
 500         if (res)
 501                 return res;
 502         bdev->bd_invalidated = 0;
 503
 504         disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
 505         while ((part = disk_part_iter_next(&piter)))
 506                 delete_partition(disk, part->partno);
 507         disk_part_iter_exit(&piter);
 508
 509         if (disk->fops->revalidate_disk)
 510                 disk->fops->revalidate_disk(disk);
 511         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 512                 return 0;
 513         if (IS_ERR(state))      /* I/O error reading the partition table */
 514                 return -EIO;
 515
 516         /* tell userspace that the media / partition table may have changed */
 517         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 518
 519         for (p = 1; p < state->limit; p++) {
 520                 sector_t size = state->parts[p].size;
 521                 sector_t from = state->parts[p].from;
 522                 if (!size)
 523                         continue;
 524                 if (from + size > get_capacity(disk)) {
 525                         printk(KERN_WARNING
 526                                 "%s: p%d exceeds device capacity\n",
 527                                 disk->disk_name, p);
 528                 }
 529                 res = add_partition(disk, p, from, size, state->parts[p].flags);
 530                 if (res) {
 531                         printk(KERN_ERR " %s: p%d could not be added: %d\n",
 532                                 disk->disk_name, p, -res);
 533                         continue;
 534                 }
 535 #ifdef CONFIG_BLK_DEV_MD
 536                 if (state->parts[p].flags & ADDPART_FLAG_RAID)
 537                         md_autodetect_dev(bdev->bd_dev+p);
 538 #endif
 539         }
 540         kfree(state);
 541         return 0;
 542 }
 543
 544 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 545 {
 546         struct address_space *mapping = bdev->bd_inode->i_mapping;
 547         struct page *page;
 548
 549         page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 550                                  NULL);
 551         if (!IS_ERR(page)) {
 552                 if (PageError(page))
 553                         goto fail;
 554                 p->v = page;
 555                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 556 fail:
 557                 page_cache_release(page);
 558         }
 559         p->v = NULL;
 560         return NULL;
 561 }
 562
 563 EXPORT_SYMBOL(read_dev_sector);
 564
 565 void del_gendisk(struct gendisk *disk)
 566 {
 567         struct disk_part_iter piter;
 568         struct hd_struct *part;
 569
 570         /* invalidate stuff */
 571         disk_part_iter_init(&piter, disk,
 572                              DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
 573         while ((part = disk_part_iter_next(&piter))) {
 574                 invalidate_partition(disk, part->partno);
 575                 delete_partition(disk, part->partno);
 576         }
 577         disk_part_iter_exit(&piter);
 578
 579         invalidate_partition(disk, 0);
 580         set_capacity(disk, 0);
 581         disk->flags &= ~GENHD_FL_UP;
 582         unlink_gendisk(disk);
 583         disk_stat_set_all(disk, 0);
 584         disk->stamp = 0;
 585
 586         kobject_put(disk->part0.holder_dir);
 587         kobject_put(disk->slave_dir);
 588         disk->driverfs_dev = NULL;
 589 #ifndef CONFIG_SYSFS_DEPRECATED
 590         sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
 591 #endif
 592         device_del(disk_to_dev(disk));
 593 }