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_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         NULL
 107 };
 108
 109 /*
 110  * disk_name() is used by partition check code and the genhd driver.
 111  * It formats the devicename of the indicated disk into
 112  * the supplied buffer (of size at least 32), and returns
 113  * a pointer to that same buffer (for convenience).
 114  */
 115
 116 char *disk_name(struct gendisk *hd, int part, char *buf)
 117 {
 118         if (!part)
 119                 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
 120         else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
 121                 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
 122         else
 123                 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);
 124
 125         return buf;
 126 }
 127
 128 const char *bdevname(struct block_device *bdev, char *buf)
 129 {
 130         int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
 131         return disk_name(bdev->bd_disk, part, buf);
 132 }
 133
 134 EXPORT_SYMBOL(bdevname);
 135
 136 /*
 137  * There's very little reason to use this, you should really
 138  * have a struct block_device just about everywhere and use
 139  * bdevname() instead.
 140  */
 141 const char *__bdevname(dev_t dev, char *buffer)
 142 {
 143         scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
 144                                 MAJOR(dev), MINOR(dev));
 145         return buffer;
 146 }
 147
 148 EXPORT_SYMBOL(__bdevname);
 149
 150 static struct parsed_partitions *
 151 check_partition(struct gendisk *hd, struct block_device *bdev)
 152 {
 153         struct parsed_partitions *state;
 154         int i, res;
 155
 156         state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 157         if (!state)
 158                 return NULL;
 159
 160 #ifdef CONFIG_DEVFS_FS
 161         if (hd->devfs_name[0] != '\0') {
 162                 printk(KERN_INFO " /dev/%s:", hd->devfs_name);
 163                 sprintf(state->name, "p");
 164         }
 165 #endif
 166         else {
 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 = 0;
 174         while (!res && check_part[i]) {
 175                 memset(&state->parts, 0, sizeof(state->parts));
 176                 res = check_part[i++](state, bdev);
 177         }
 178         if (res > 0)
 179                 return state;
 180         if (!res)
 181                 printk(" unknown partition table\n");
 182         else if (warn_no_part)
 183                 printk(" unable to read partition table\n");
 184         kfree(state);
 185         return NULL;
 186 }
 187
 188 /*
 189  * sysfs bindings for partitions
 190  */
 191
 192 struct part_attribute {
 193         struct attribute attr;
 194         ssize_t (*show)(struct hd_struct *,char *);
 195         ssize_t (*store)(struct hd_struct *,const char *, size_t);
 196 };
 197
 198 static ssize_t
 199 part_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
 200 {
 201         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 202         struct part_attribute * part_attr = container_of(attr,struct part_attribute,attr);
 203         ssize_t ret = 0;
 204         if (part_attr->show)
 205                 ret = part_attr->show(p, page);
 206         return ret;
 207 }
 208 static ssize_t
 209 part_attr_store(struct kobject * kobj, struct attribute * attr,
 210                 const char *page, size_t count)
 211 {
 212         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 213         struct part_attribute * part_attr = container_of(attr,struct part_attribute,attr);
 214         ssize_t ret = 0;
 215
 216         if (part_attr->store)
 217                 ret = part_attr->store(p, page, count);
 218         return ret;
 219 }
 220
 221 static struct sysfs_ops part_sysfs_ops = {
 222         .show   =       part_attr_show,
 223         .store  =       part_attr_store,
 224 };
 225
 226 static ssize_t part_uevent_store(struct hd_struct * p,
 227                                  const char *page, size_t count)
 228 {
 229         kobject_hotplug(&p->kobj, KOBJ_ADD);
 230         return count;
 231 }
 232 static ssize_t part_dev_read(struct hd_struct * p, char *page)
 233 {
 234         struct gendisk *disk = container_of(p->kobj.parent,struct gendisk,kobj);
 235         dev_t dev = MKDEV(disk->major, disk->first_minor + p->partno);
 236         return print_dev_t(page, dev);
 237 }
 238 static ssize_t part_start_read(struct hd_struct * p, char *page)
 239 {
 240         return sprintf(page, "%llu\n",(unsigned long long)p->start_sect);
 241 }
 242 static ssize_t part_size_read(struct hd_struct * p, char *page)
 243 {
 244         return sprintf(page, "%llu\n",(unsigned long long)p->nr_sects);
 245 }
 246 static ssize_t part_stat_read(struct hd_struct * p, char *page)
 247 {
 248         return sprintf(page, "%8u %8llu %8u %8llu\n",
 249                        p->reads, (unsigned long long)p->read_sectors,
 250                        p->writes, (unsigned long long)p->write_sectors);
 251 }
 252 static struct part_attribute part_attr_uevent = {
 253         .attr = {.name = "uevent", .mode = S_IWUSR },
 254         .store  = part_uevent_store
 255 };
 256 static struct part_attribute part_attr_dev = {
 257         .attr = {.name = "dev", .mode = S_IRUGO },
 258         .show   = part_dev_read
 259 };
 260 static struct part_attribute part_attr_start = {
 261         .attr = {.name = "start", .mode = S_IRUGO },
 262         .show   = part_start_read
 263 };
 264 static struct part_attribute part_attr_size = {
 265         .attr = {.name = "size", .mode = S_IRUGO },
 266         .show   = part_size_read
 267 };
 268 static struct part_attribute part_attr_stat = {
 269         .attr = {.name = "stat", .mode = S_IRUGO },
 270         .show   = part_stat_read
 271 };
 272
 273 static struct attribute * default_attrs[] = {
 274         &part_attr_uevent.attr,
 275         &part_attr_dev.attr,
 276         &part_attr_start.attr,
 277         &part_attr_size.attr,
 278         &part_attr_stat.attr,
 279         NULL,
 280 };
 281
 282 extern struct subsystem block_subsys;
 283
 284 static void part_release(struct kobject *kobj)
 285 {
 286         struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
 287         kfree(p);
 288 }
 289
 290 struct kobj_type ktype_part = {
 291         .release        = part_release,
 292         .default_attrs  = default_attrs,
 293         .sysfs_ops      = &part_sysfs_ops,
 294 };
 295
 296 void delete_partition(struct gendisk *disk, int part)
 297 {
 298         struct hd_struct *p = disk->part[part-1];
 299         if (!p)
 300                 return;
 301         if (!p->nr_sects)
 302                 return;
 303         disk->part[part-1] = NULL;
 304         p->start_sect = 0;
 305         p->nr_sects = 0;
 306         p->reads = p->writes = p->read_sectors = p->write_sectors = 0;
 307         devfs_remove("%s/part%d", disk->devfs_name, part);
 308         kobject_unregister(&p->kobj);
 309 }
 310
 311 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len)
 312 {
 313         struct hd_struct *p;
 314
 315         p = kmalloc(sizeof(*p), GFP_KERNEL);
 316         if (!p)
 317                 return;
 318
 319         memset(p, 0, sizeof(*p));
 320         p->start_sect = start;
 321         p->nr_sects = len;
 322         p->partno = part;
 323
 324         devfs_mk_bdev(MKDEV(disk->major, disk->first_minor + part),
 325                         S_IFBLK|S_IRUSR|S_IWUSR,
 326                         "%s/part%d", disk->devfs_name, part);
 327
 328         if (isdigit(disk->kobj.name[strlen(disk->kobj.name)-1]))
 329                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%sp%d",disk->kobj.name,part);
 330         else
 331                 snprintf(p->kobj.name,KOBJ_NAME_LEN,"%s%d",disk->kobj.name,part);
 332         p->kobj.parent = &disk->kobj;
 333         p->kobj.ktype = &ktype_part;
 334         kobject_register(&p->kobj);
 335         disk->part[part-1] = p;
 336 }
 337
 338 static void disk_sysfs_symlinks(struct gendisk *disk)
 339 {
 340         struct device *target = get_device(disk->driverfs_dev);
 341         if (target) {
 342                 sysfs_create_link(&disk->kobj,&target->kobj,"device");
 343                 sysfs_create_link(&target->kobj,&disk->kobj,"block");
 344         }
 345 }
 346
 347 /* Not exported, helper to add_disk(). */
 348 void register_disk(struct gendisk *disk)
 349 {
 350         struct block_device *bdev;
 351         char *s;
 352         int err;
 353
 354         strlcpy(disk->kobj.name,disk->disk_name,KOBJ_NAME_LEN);
 355         /* ewww... some of these buggers have / in name... */
 356         s = strchr(disk->kobj.name, '/');
 357         if (s)
 358                 *s = '!';
 359         if ((err = kobject_add(&disk->kobj)))
 360                 return;
 361         disk_sysfs_symlinks(disk);
 362         kobject_hotplug(&disk->kobj, KOBJ_ADD);
 363
 364         /* No minors to use for partitions */
 365         if (disk->minors == 1) {
 366                 if (disk->devfs_name[0] != '\0')
 367                         devfs_add_disk(disk);
 368                 return;
 369         }
 370
 371         /* always add handle for the whole disk */
 372         devfs_add_partitioned(disk);
 373
 374         /* No such device (e.g., media were just removed) */
 375         if (!get_capacity(disk))
 376                 return;
 377
 378         bdev = bdget_disk(disk, 0);
 379         if (!bdev)
 380                 return;
 381
 382         bdev->bd_invalidated = 1;
 383         if (blkdev_get(bdev, FMODE_READ, 0) < 0)
 384                 return;
 385         blkdev_put(bdev);
 386 }
 387
 388 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 389 {
 390         struct parsed_partitions *state;
 391         int p, res;
 392
 393         if (bdev->bd_part_count)
 394                 return -EBUSY;
 395         res = invalidate_partition(disk, 0);
 396         if (res)
 397                 return res;
 398         bdev->bd_invalidated = 0;
 399         for (p = 1; p < disk->minors; p++)
 400                 delete_partition(disk, p);
 401         if (disk->fops->revalidate_disk)
 402                 disk->fops->revalidate_disk(disk);
 403         if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 404                 return 0;
 405         for (p = 1; p < state->limit; p++) {
 406                 sector_t size = state->parts[p].size;
 407                 sector_t from = state->parts[p].from;
 408                 if (!size)
 409                         continue;
 410                 add_partition(disk, p, from, size);
 411 #ifdef CONFIG_BLK_DEV_MD
 412                 if (state->parts[p].flags)
 413                         md_autodetect_dev(bdev->bd_dev+p);
 414 #endif
 415         }
 416         kfree(state);
 417         return 0;
 418 }
 419
 420 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 421 {
 422         struct address_space *mapping = bdev->bd_inode->i_mapping;
 423         struct page *page;
 424
 425         page = read_cache_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
 426                         (filler_t *)mapping->a_ops->readpage, NULL);
 427         if (!IS_ERR(page)) {
 428                 wait_on_page_locked(page);
 429                 if (!PageUptodate(page))
 430                         goto fail;
 431                 if (PageError(page))
 432                         goto fail;
 433                 p->v = page;
 434                 return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
 435 fail:
 436                 page_cache_release(page);
 437         }
 438         p->v = NULL;
 439         return NULL;
 440 }
 441
 442 EXPORT_SYMBOL(read_dev_sector);
 443
 444 void del_gendisk(struct gendisk *disk)
 445 {
 446         int p;
 447
 448         /* invalidate stuff */
 449         for (p = disk->minors - 1; p > 0; p--) {
 450                 invalidate_partition(disk, p);
 451                 delete_partition(disk, p);
 452         }
 453         invalidate_partition(disk, 0);
 454         disk->capacity = 0;
 455         disk->flags &= ~GENHD_FL_UP;
 456         unlink_gendisk(disk);
 457         disk_stat_set_all(disk, 0);
 458         disk->stamp = disk->stamp_idle = 0;
 459
 460         devfs_remove_disk(disk);
 461
 462         if (disk->driverfs_dev) {
 463                 sysfs_remove_link(&disk->kobj, "device");
 464                 sysfs_remove_link(&disk->driverfs_dev->kobj, "block");
 465                 put_device(disk->driverfs_dev);
 466         }
 467         kobject_hotplug(&disk->kobj, KOBJ_REMOVE);
 468         kobject_del(&disk->kobj);
 469 }