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 /*
 199  * sysfs bindings for partitions
 200  */
 201
 202 struct part_attribute {
 203         struct attribute attr;
 204         ssize_t (*show)(struct hd_struct *,char *);
 205         ssize_t (*store)(struct hd_struct *,const char *, size_t);
 206 };
 207
 208 static ssize_t
 209 part_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
 210 {
 211         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 212         struct part_attribute * part_attr = container_of(attr,struct part_attribute,attr);
 213         ssize_t ret = 0;
 214         if (part_attr->show)
 215                 ret = part_attr->show(p, page);
 216         return ret;
 217 }
 218 static ssize_t
 219 part_attr_store(struct kobject * kobj, struct attribute * attr,
 220                 const char *page, size_t count)
 221 {
 222         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 223         struct part_attribute * part_attr = container_of(attr,struct part_attribute,attr);
 224         ssize_t ret = 0;
 225
 226         if (part_attr->store)
 227                 ret = part_attr->store(p, page, count);
 228         return ret;
 229 }
 230
 231 static struct sysfs_ops part_sysfs_ops = {
 232         .show   =       part_attr_show,
 233         .store  =       part_attr_store,
 234 };
 235
 236 static ssize_t part_uevent_store(struct hd_struct * p,
 237                                  const char *page, size_t count)
 238 {
 239         kobject_uevent(&p->kobj, KOBJ_ADD);
 240         return count;
 241 }
 242 static ssize_t part_dev_read(struct hd_struct * p, char *page)
 243 {
 244         struct gendisk *disk = container_of(p->kobj.parent,struct gendisk,kobj);
 245         dev_t dev = MKDEV(disk->major, disk->first_minor + p->partno);
 246         return print_dev_t(page, dev);
 247 }
 248 static ssize_t part_start_read(struct hd_struct * p, char *page)
 249 {
 250         return sprintf(page, "%llu\n",(unsigned long long)p->start_sect);
 251 }
 252 static ssize_t part_size_read(struct hd_struct * p, char *page)
 253 {
 254         return sprintf(page, "%llu\n",(unsigned long long)p->nr_sects);
 255 }
 256 static ssize_t part_stat_read(struct hd_struct * p, char *page)
 257 {
 258         return sprintf(page, "%8u %8llu %8u %8llu\n",
 259                        p->ios[0], (unsigned long long)p->sectors[0],
 260                        p->ios[1], (unsigned long long)p->sectors[1]);
 261 }
 262 static struct part_attribute part_attr_uevent = {
 263         .attr = {.name = "uevent", .mode = S_IWUSR },
 264         .store  = part_uevent_store
 265 };
 266 static struct part_attribute part_attr_dev = {
 267         .attr = {.name = "dev", .mode = S_IRUGO },
 268         .show   = part_dev_read
 269 };
 270 static struct part_attribute part_attr_start = {
 271         .attr = {.name = "start", .mode = S_IRUGO },
 272         .show   = part_start_read
 273 };
 274 static struct part_attribute part_attr_size = {
 275         .attr = {.name = "size", .mode = S_IRUGO },
 276         .show   = part_size_read
 277 };
 278 static struct part_attribute part_attr_stat = {
 279         .attr = {.name = "stat", .mode = S_IRUGO },
 280         .show   = part_stat_read
 281 };
 282
 283 #ifdef CONFIG_FAIL_MAKE_REQUEST
 284
 285 static ssize_t part_fail_store(struct hd_struct * p,
 286                                const char *buf, size_t count)
 287 {
 288         int i;
 289
 290         if (count > 0 && sscanf(buf, "%d", &i) > 0)
 291                 p->make_it_fail = (i == 0) ? 0 : 1;
 292
 293         return count;
 294 }
 295 static ssize_t part_fail_read(struct hd_struct * p, char *page)
 296 {
 297         return sprintf(page, "%d\n", p->make_it_fail);
 298 }
 299 static struct part_attribute part_attr_fail = {
 300         .attr = {.name = "make-it-fail", .mode = S_IRUGO | S_IWUSR },
 301         .store  = part_fail_store,
 302         .show   = part_fail_read
 303 };
 304
 305 #endif
 306
 307 static struct attribute * default_attrs[] = {
 308         &part_attr_uevent.attr,
 309         &part_attr_dev.attr,
 310         &part_attr_start.attr,
 311         &part_attr_size.attr,
 312         &part_attr_stat.attr,
 313 #ifdef CONFIG_FAIL_MAKE_REQUEST
 314         &part_attr_fail.attr,
 315 #endif
 316         NULL,
 317 };
 318
 319 extern struct kset block_subsys;
 320
 321 static void part_release(struct kobject *kobj)
 322 {
 323         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 324         kfree(p);
 325 }
 326
 327 struct kobj_type ktype_part = {
 328         .release        = part_release,
 329         .default_attrs  = default_attrs,
 330         .sysfs_ops      = &part_sysfs_ops,
 331 };
 332
 333 static inline void partition_sysfs_add_subdir(struct hd_struct *p)
 334 {
 335         struct kobject *k;
 336
 337         k = kobject_get(&p->kobj);
 338         p->holder_dir = kobject_add_dir(k, "holders");
 339         kobject_put(k);
 340 }
 341
 342 static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
 343 {
 344         struct kobject *k;
 345
 346         k = kobject_get(&disk->kobj);
 347         disk->holder_dir = kobject_add_dir(k, "holders");
 348         disk->slave_dir = kobject_add_dir(k, "slaves");
 349         kobject_put(k);
 350 }
 351
 352 void delete_partition(struct gendisk *disk, int part)
 353 {
 354         struct hd_struct *p = disk->part[part-1];
 355         if (!p)
 356                 return;
 357         if (!p->nr_sects)
 358                 return;
 359         disk->part[part-1] = NULL;
 360         p->start_sect = 0;
 361         p->nr_sects = 0;
 362         p->ios[0] = p->ios[1] = 0;
 363         p->sectors[0] = p->sectors[1] = 0;
 364         sysfs_remove_link(&p->kobj, "subsystem");
 365         kobject_unregister(p->holder_dir);
 366         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 367         kobject_del(&p->kobj);
 368         kobject_put(&p->kobj);
 369 }
 370
 371 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
 372 {
 373         struct hd_struct *p;
 374
 375         p = kmalloc(sizeof(*p), GFP_KERNEL);
 376         if (!p)
 377                 return;
 378
 379         memset(p, 0, sizeof(*p));
 380         p->start_sect = start;
 381         p->nr_sects = len;
 382         p->partno = part;
 383         p->policy = disk->policy;
 384
 385         if (isdigit(disk->kobj.name[strlen(disk->kobj.name)-1]))
 386                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%sp%d",disk->kobj.name,part);
 387         else
 388                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%s%d",disk->kobj.name,part);
 389         p->kobj.parent = &disk->kobj;
 390         p->kobj.ktype = &ktype_part;
 391         kobject_init(&p->kobj);
 392         kobject_add(&p->kobj);
 393         if (!disk->part_uevent_suppress)
 394                 kobject_uevent(&p->kobj, KOBJ_ADD);
 395         sysfs_create_link(&p->kobj, &block_subsys.kobj, "subsystem");
 396         if (flags & ADDPART_FLAG_WHOLEDISK) {
 397                 static struct attribute addpartattr = {
 398                         .name = "whole_disk",
 399                         .mode = S_IRUSR | S_IRGRP | S_IROTH,
 400                 };
 401
 402                 sysfs_create_file(&p->kobj, &addpartattr);
 403         }
 404         partition_sysfs_add_subdir(p);
 405         disk->part[part-1] = p;
 406 }
 407
 408 static char *make_block_name(struct gendisk *disk)
 409 {
 410         char *name;
 411         static char *block_str = "block:";
 412         int size;
 413         char *s;
 414
 415         size = strlen(block_str) + strlen(disk->disk_name) + 1;
 416         name = kmalloc(size, GFP_KERNEL);
 417         if (!name)
 418                 return NULL;
 419         strcpy(name, block_str);
 420         strcat(name, disk->disk_name);
 421         /* ewww... some of these buggers have / in name... */
 422         s = strchr(name, '/');
 423         if (s)
 424                 *s = '!';
 425         return name;
 426 }
 427
 428 static int disk_sysfs_symlinks(struct gendisk *disk)
 429 {
 430         struct device *target = get_device(disk->driverfs_dev);
 431         int err;
 432         char *disk_name = NULL;
 433
 434         if (target) {
 435                 disk_name = make_block_name(disk);
 436                 if (!disk_name) {
 437                         err = -ENOMEM;
 438                         goto err_out;
 439                 }
 440
 441                 err = sysfs_create_link(&disk->kobj, &target->kobj, "device");
 442                 if (err)
 443                         goto err_out_disk_name;
 444
 445                 err = sysfs_create_link(&target->kobj, &disk->kobj, disk_name);
 446                 if (err)
 447                         goto err_out_dev_link;
 448         }
 449
 450         err = sysfs_create_link(&disk->kobj, &block_subsys.kobj,
 451                                 "subsystem");
 452         if (err)
 453                 goto err_out_disk_name_lnk;
 454
 455         kfree(disk_name);
 456
 457         return 0;
 458
 459 err_out_disk_name_lnk:
 460         if (target) {
 461                 sysfs_remove_link(&target->kobj, disk_name);
 462 err_out_dev_link:
 463                 sysfs_remove_link(&disk->kobj, "device");
 464 err_out_disk_name:
 465                 kfree(disk_name);
 466 err_out:
 467                 put_device(target);
 468         }
 469         return err;
 470 }
 471
 472 /* Not exported, helper to add_disk(). */
 473 void register_disk(struct gendisk *disk)
 474 {
 475         struct block_device *bdev;
 476         char *s;
 477         int i;
 478         struct hd_struct *p;
 479         int err;
 480
 481         strlcpy(disk->kobj.name,disk->disk_name,KOBJ_NAME_LEN);
 482         /* ewww... some of these buggers have / in name... */
 483         s = strchr(disk->kobj.name, '/');
 484         if (s)
 485                 *s = '!';
 486         if ((err = kobject_add(&disk->kobj)))
 487                 return;
 488         err = disk_sysfs_symlinks(disk);
 489         if (err) {
 490                 kobject_del(&disk->kobj);
 491                 return;
 492         }
 493         disk_sysfs_add_subdirs(disk);
 494
 495         /* No minors to use for partitions */
 496         if (disk->minors == 1)
 497                 goto exit;
 498
 499         /* No such device (e.g., media were just removed) */
 500         if (!get_capacity(disk))
 501                 goto exit;
 502
 503         bdev = bdget_disk(disk, 0);
 504         if (!bdev)
 505                 goto exit;
 506
 507         /* scan partition table, but suppress uevents */
 508         bdev->bd_invalidated = 1;
 509         disk->part_uevent_suppress = 1;
 510         err = blkdev_get(bdev, FMODE_READ, 0);
 511         disk->part_uevent_suppress = 0;
 512         if (err < 0)
 513                 goto exit;
 514         blkdev_put(bdev);
 515
 516 exit:
 517         /* announce disk after possible partitions are already created */
 518         kobject_uevent(&disk->kobj, KOBJ_ADD);
 519
 520         /* announce possible partitions */
 521         for (i = 1; i < disk->minors; i++) {
 522                 p = disk->part[i-1];
 523                 if (!p || !p->nr_sects)
 524                         continue;
 525                 kobject_uevent(&p->kobj, KOBJ_ADD);
 526         }
 527 }
 528
 529 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 530 {
 531         struct parsed_partitions *state;
 532         int p, res;
 533
 534         if (bdev->bd_part_count)
 535                 return -EBUSY;
 536         res = invalidate_partition(disk, 0);
 537         if (res)
 538                 return res;
 539         bdev->bd_invalidated = 0;
 540         for (p = 1; p < disk->minors; p++)
 541                 delete_partition(disk, p);
 542         if (disk->fops->revalidate_disk)
 543                 disk->fops->revalidate_disk(disk);
 544         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 545                 return 0;
 546         if (IS_ERR(state))      /* I/O error reading the partition table */
 547                 return -EIO;
 548         for (p = 1; p < state->limit; p++) {
 549                 sector_t size = state->parts[p].size;
 550                 sector_t from = state->parts[p].from;
 551                 if (!size)
 552                         continue;
 553                 if (from + size > get_capacity(disk)) {
 554                         printk(" %s: p%d exceeds device capacity\n",
 555                                 disk->disk_name, p);
 556                 }
 557                 add_partition(disk, p, from, size, state->parts[p].flags);
 558 #ifdef CONFIG_BLK_DEV_MD
 559                 if (state->parts[p].flags & ADDPART_FLAG_RAID)
 560                         md_autodetect_dev(bdev->bd_dev+p);
 561 #endif
 562         }
 563         kfree(state);
 564         return 0;
 565 }
 566
 567 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 568 {
 569         struct address_space *mapping = bdev->bd_inode->i_mapping;
 570         struct page *page;
 571
 572         page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 573                                  NULL);
 574         if (!IS_ERR(page)) {
 575                 if (PageError(page))
 576                         goto fail;
 577                 p->v = page;
 578                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 579 fail:
 580                 page_cache_release(page);
 581         }
 582         p->v = NULL;
 583         return NULL;
 584 }
 585
 586 EXPORT_SYMBOL(read_dev_sector);
 587
 588 void del_gendisk(struct gendisk *disk)
 589 {
 590         int p;
 591
 592         /* invalidate stuff */
 593         for (p = disk->minors - 1; p > 0; p--) {
 594                 invalidate_partition(disk, p);
 595                 delete_partition(disk, p);
 596         }
 597         invalidate_partition(disk, 0);
 598         disk->capacity = 0;
 599         disk->flags &= ~GENHD_FL_UP;
 600         unlink_gendisk(disk);
 601         disk_stat_set_all(disk, 0);
 602         disk->stamp = 0;
 603
 604         kobject_uevent(&disk->kobj, KOBJ_REMOVE);
 605         kobject_unregister(disk->holder_dir);
 606         kobject_unregister(disk->slave_dir);
 607         if (disk->driverfs_dev) {
 608                 char *disk_name = make_block_name(disk);
 609                 sysfs_remove_link(&disk->kobj, "device");
 610                 if (disk_name) {
 611                         sysfs_remove_link(&disk->driverfs_dev->kobj, disk_name);
 612                         kfree(disk_name);
 613                 }
 614                 put_device(disk->driverfs_dev);
 615                 disk->driverfs_dev = NULL;
 616         }
 617         sysfs_remove_link(&disk->kobj, "subsystem");
 618         kobject_del(&disk->kobj);
 619 }