include/linux/genhd.h

   1 #ifndef _LINUX_GENHD_H
   2 #define _LINUX_GENHD_H
   3
   4 /*
   5  *      genhd.h Copyright (C) 1992 Drew Eckhardt
   6  *      Generic hard disk header file by
   7  *              Drew Eckhardt
   8  *
   9  *              <drew@colorado.edu>
  10  */
  11
  12 #include <linux/types.h>
  13 #include <linux/kdev_t.h>
  14 #include <linux/rcupdate.h>
  15 #include <linux/slab.h>
  16
  17 #ifdef CONFIG_BLOCK
  18
  19 #define kobj_to_dev(k)          container_of((k), struct device, kobj)
  20 #define dev_to_disk(device)     container_of((device), struct gendisk, part0.__dev)
  21 #define dev_to_part(device)     container_of((device), struct hd_struct, __dev)
  22 #define disk_to_dev(disk)       (&(disk)->part0.__dev)
  23 #define part_to_dev(part)       (&((part)->__dev))
  24 #define alias_name(disk)        ((disk)->alias ? (disk)->alias : \
  25                                                  (disk)->disk_name)
  26
  27 extern struct device_type part_type;
  28 extern struct kobject *block_depr;
  29 extern struct class block_class;
  30
  31 enum {
  32 /* These three have identical behaviour; use the second one if DOS FDISK gets
  33    confused about extended/logical partitions starting past cylinder 1023. */
  34         DOS_EXTENDED_PARTITION = 5,
  35         LINUX_EXTENDED_PARTITION = 0x85,
  36         WIN98_EXTENDED_PARTITION = 0x0f,
  37
  38         SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
  39
  40         LINUX_SWAP_PARTITION = 0x82,
  41         LINUX_DATA_PARTITION = 0x83,
  42         LINUX_LVM_PARTITION = 0x8e,
  43         LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
  44
  45         SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
  46         NEW_SOLARIS_X86_PARTITION = 0xbf,
  47
  48         DM6_AUX1PARTITION = 0x51,       /* no DDO:  use xlated geom */
  49         DM6_AUX3PARTITION = 0x53,       /* no DDO:  use xlated geom */
  50         DM6_PARTITION = 0x54,           /* has DDO: use xlated geom & offset */
  51         EZD_PARTITION = 0x55,           /* EZ-DRIVE */
  52
  53         FREEBSD_PARTITION = 0xa5,       /* FreeBSD Partition ID */
  54         OPENBSD_PARTITION = 0xa6,       /* OpenBSD Partition ID */
  55         NETBSD_PARTITION = 0xa9,        /* NetBSD Partition ID */
  56         BSDI_PARTITION = 0xb7,          /* BSDI Partition ID */
  57         MINIX_PARTITION = 0x81,         /* Minix Partition ID */
  58         UNIXWARE_PARTITION = 0x63,      /* Same as GNU_HURD and SCO Unix */
  59 };
  60
  61 #define DISK_MAX_PARTS                  256
  62 #define DISK_NAME_LEN                   32
  63 #define ALIAS_LEN                       256
  64
  65 #include <linux/major.h>
  66 #include <linux/device.h>
  67 #include <linux/smp.h>
  68 #include <linux/string.h>
  69 #include <linux/fs.h>
  70 #include <linux/workqueue.h>
  71
  72 struct partition {
  73         unsigned char boot_ind;         /* 0x80 - active */
  74         unsigned char head;             /* starting head */
  75         unsigned char sector;           /* starting sector */
  76         unsigned char cyl;              /* starting cylinder */
  77         unsigned char sys_ind;          /* What partition type */
  78         unsigned char end_head;         /* end head */
  79         unsigned char end_sector;       /* end sector */
  80         unsigned char end_cyl;          /* end cylinder */
  81         __le32 start_sect;      /* starting sector counting from 0 */
  82         __le32 nr_sects;                /* nr of sectors in partition */
  83 } __attribute__((packed));
  84
  85 struct disk_stats {
  86         unsigned long sectors[2];       /* READs and WRITEs */
  87         unsigned long ios[2];
  88         unsigned long merges[2];
  89         unsigned long ticks[2];
  90         unsigned long io_ticks;
  91         unsigned long time_in_queue;
  92 };
  93
  94 #define PARTITION_META_INFO_VOLNAMELTH  64
  95 #define PARTITION_META_INFO_UUIDLTH     16
  96
  97 struct partition_meta_info {
  98         u8 uuid[PARTITION_META_INFO_UUIDLTH];   /* always big endian */
  99         u8 volname[PARTITION_META_INFO_VOLNAMELTH];
 100 };
 101
 102 struct hd_struct {
 103         sector_t start_sect;
 104         sector_t nr_sects;
 105         sector_t alignment_offset;
 106         unsigned int discard_alignment;
 107         struct device __dev;
 108         struct kobject *holder_dir;
 109         int policy, partno;
 110         struct partition_meta_info *info;
 111 #ifdef CONFIG_FAIL_MAKE_REQUEST
 112         int make_it_fail;
 113 #endif
 114         unsigned long stamp;
 115         atomic_t in_flight[2];
 116 #ifdef  CONFIG_SMP
 117         struct disk_stats __percpu *dkstats;
 118 #else
 119         struct disk_stats dkstats;
 120 #endif
 121         atomic_t ref;
 122         struct rcu_head rcu_head;
 123 };
 124
 125 #define GENHD_FL_REMOVABLE                      1
 126 /* 2 is unused */
 127 #define GENHD_FL_MEDIA_CHANGE_NOTIFY            4
 128 #define GENHD_FL_CD                             8
 129 #define GENHD_FL_UP                             16
 130 #define GENHD_FL_SUPPRESS_PARTITION_INFO        32
 131 #define GENHD_FL_EXT_DEVT                       64 /* allow extended devt */
 132 #define GENHD_FL_NATIVE_CAPACITY                128
 133 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE     256
 134 #define GENHD_FL_NO_PART_SCAN                   512
 135
 136 enum {
 137         DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 138         DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 139 };
 140
 141 #define BLK_SCSI_MAX_CMDS       (256)
 142 #define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 143
 144 struct blk_scsi_cmd_filter {
 145         unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
 146         unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
 147         struct kobject kobj;
 148 };
 149
 150 struct disk_part_tbl {
 151         struct rcu_head rcu_head;
 152         int len;
 153         struct hd_struct __rcu *last_lookup;
 154         struct hd_struct __rcu *part[];
 155 };
 156
 157 struct disk_events;
 158
 159 struct gendisk {
 160         /* major, first_minor and minors are input parameters only,
 161          * don't use directly.  Use disk_devt() and disk_max_parts().
 162          */
 163         int major;                      /* major number of driver */
 164         int first_minor;
 165         int minors;                     /* maximum number of minors, =1 for
 166                                          * disks that can't be partitioned. */
 167
 168         char disk_name[DISK_NAME_LEN];  /* name of major driver */
 169         char *alias;                    /* alias name of disk */
 170         char *(*devnode)(struct gendisk *gd, mode_t *mode);
 171
 172         unsigned int events;            /* supported events */
 173         unsigned int async_events;      /* async events, subset of all */
 174
 175         /* Array of pointers to partitions indexed by partno.
 176          * Protected with matching bdev lock but stat and other
 177          * non-critical accesses use RCU.  Always access through
 178          * helpers.
 179          */
 180         struct disk_part_tbl __rcu *part_tbl;
 181         struct hd_struct part0;
 182
 183         const struct block_device_operations *fops;
 184         struct request_queue *queue;
 185         void *private_data;
 186
 187         int flags;
 188         struct device *driverfs_dev;  // FIXME: remove
 189         struct kobject *slave_dir;
 190
 191         struct timer_rand_state *random;
 192         atomic_t sync_io;               /* RAID */
 193         struct disk_events *ev;
 194 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 195         struct blk_integrity *integrity;
 196 #endif
 197         int node_id;
 198 };
 199
 200 static inline struct gendisk *part_to_disk(struct hd_struct *part)
 201 {
 202         if (likely(part)) {
 203                 if (part->partno)
 204                         return dev_to_disk(part_to_dev(part)->parent);
 205                 else
 206                         return dev_to_disk(part_to_dev(part));
 207         }
 208         return NULL;
 209 }
 210
 211 static inline void part_pack_uuid(const u8 *uuid_str, u8 *to)
 212 {
 213         int i;
 214         for (i = 0; i < 16; ++i) {
 215                 *to++ = (hex_to_bin(*uuid_str) << 4) |
 216                         (hex_to_bin(*(uuid_str + 1)));
 217                 uuid_str += 2;
 218                 switch (i) {
 219                 case 3:
 220                 case 5:
 221                 case 7:
 222                 case 9:
 223                         uuid_str++;
 224                         continue;
 225                 }
 226         }
 227 }
 228
 229 static inline char *part_unpack_uuid(const u8 *uuid, char *out)
 230 {
 231         sprintf(out, "%pU", uuid);
 232         return out;
 233 }
 234
 235 static inline int disk_max_parts(struct gendisk *disk)
 236 {
 237         if (disk->flags & GENHD_FL_EXT_DEVT)
 238                 return DISK_MAX_PARTS;
 239         return disk->minors;
 240 }
 241
 242 static inline bool disk_part_scan_enabled(struct gendisk *disk)
 243 {
 244         return disk_max_parts(disk) > 1 &&
 245                 !(disk->flags & GENHD_FL_NO_PART_SCAN);
 246 }
 247
 248 static inline dev_t disk_devt(struct gendisk *disk)
 249 {
 250         return disk_to_dev(disk)->devt;
 251 }
 252
 253 static inline dev_t part_devt(struct hd_struct *part)
 254 {
 255         return part_to_dev(part)->devt;
 256 }
 257
 258 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 259
 260 static inline void disk_put_part(struct hd_struct *part)
 261 {
 262         if (likely(part))
 263                 put_device(part_to_dev(part));
 264 }
 265
 266 /*
 267  * Smarter partition iterator without context limits.
 268  */
 269 #define DISK_PITER_REVERSE      (1 << 0) /* iterate in the reverse direction */
 270 #define DISK_PITER_INCL_EMPTY   (1 << 1) /* include 0-sized parts */
 271 #define DISK_PITER_INCL_PART0   (1 << 2) /* include partition 0 */
 272 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
 273
 274 struct disk_part_iter {
 275         struct gendisk          *disk;
 276         struct hd_struct        *part;
 277         int                     idx;
 278         unsigned int            flags;
 279 };
 280
 281 extern void disk_part_iter_init(struct disk_part_iter *piter,
 282                                  struct gendisk *disk, unsigned int flags);
 283 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 284 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 285
 286 extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 287                                              sector_t sector);
 288
 289 /*
 290  * Macros to operate on percpu disk statistics:
 291  *
 292  * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 293  * and should be called between disk_stat_lock() and
 294  * disk_stat_unlock().
 295  *
 296  * part_stat_read() can be called at any time.
 297  *
 298  * part_stat_{add|set_all}() and {init|free}_part_stats are for
 299  * internal use only.
 300  */
 301 #ifdef  CONFIG_SMP
 302 #define part_stat_lock()        ({ rcu_read_lock(); get_cpu(); })
 303 #define part_stat_unlock()      do { put_cpu(); rcu_read_unlock(); } while (0)
 304
 305 #define __part_stat_add(cpu, part, field, addnd)                        \
 306         (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
 307
 308 #define part_stat_read(part, field)                                     \
 309 ({                                                                      \
 310         typeof((part)->dkstats->field) res = 0;                         \
 311         unsigned int _cpu;                                              \
 312         for_each_possible_cpu(_cpu)                                     \
 313                 res += per_cpu_ptr((part)->dkstats, _cpu)->field;       \
 314         res;                                                            \
 315 })
 316
 317 static inline void part_stat_set_all(struct hd_struct *part, int value)
 318 {
 319         int i;
 320
 321         for_each_possible_cpu(i)
 322                 memset(per_cpu_ptr(part->dkstats, i), value,
 323                                 sizeof(struct disk_stats));
 324 }
 325
 326 static inline int init_part_stats(struct hd_struct *part)
 327 {
 328         part->dkstats = alloc_percpu(struct disk_stats);
 329         if (!part->dkstats)
 330                 return 0;
 331         return 1;
 332 }
 333
 334 static inline void free_part_stats(struct hd_struct *part)
 335 {
 336         free_percpu(part->dkstats);
 337 }
 338
 339 #else /* !CONFIG_SMP */
 340 #define part_stat_lock()        ({ rcu_read_lock(); 0; })
 341 #define part_stat_unlock()      rcu_read_unlock()
 342
 343 #define __part_stat_add(cpu, part, field, addnd)                                \
 344         ((part)->dkstats.field += addnd)
 345
 346 #define part_stat_read(part, field)     ((part)->dkstats.field)
 347
 348 static inline void part_stat_set_all(struct hd_struct *part, int value)
 349 {
 350         memset(&part->dkstats, value, sizeof(struct disk_stats));
 351 }
 352
 353 static inline int init_part_stats(struct hd_struct *part)
 354 {
 355         return 1;
 356 }
 357
 358 static inline void free_part_stats(struct hd_struct *part)
 359 {
 360 }
 361
 362 #endif /* CONFIG_SMP */
 363
 364 #define part_stat_add(cpu, part, field, addnd)  do {                    \
 365         __part_stat_add((cpu), (part), field, addnd);                   \
 366         if ((part)->partno)                                             \
 367                 __part_stat_add((cpu), &part_to_disk((part))->part0,    \
 368                                 field, addnd);                          \
 369 } while (0)
 370
 371 #define part_stat_dec(cpu, gendiskp, field)                             \
 372         part_stat_add(cpu, gendiskp, field, -1)
 373 #define part_stat_inc(cpu, gendiskp, field)                             \
 374         part_stat_add(cpu, gendiskp, field, 1)
 375 #define part_stat_sub(cpu, gendiskp, field, subnd)                      \
 376         part_stat_add(cpu, gendiskp, field, -subnd)
 377
 378 static inline void part_inc_in_flight(struct hd_struct *part, int rw)
 379 {
 380         atomic_inc(&part->in_flight[rw]);
 381         if (part->partno)
 382                 atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
 383 }
 384
 385 static inline void part_dec_in_flight(struct hd_struct *part, int rw)
 386 {
 387         atomic_dec(&part->in_flight[rw]);
 388         if (part->partno)
 389                 atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
 390 }
 391
 392 static inline int part_in_flight(struct hd_struct *part)
 393 {
 394         return atomic_read(&part->in_flight[0]) + atomic_read(&part->in_flight[1]);
 395 }
 396
 397 static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
 398 {
 399         if (disk)
 400                 return kzalloc_node(sizeof(struct partition_meta_info),
 401                                     GFP_KERNEL, disk->node_id);
 402         return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
 403 }
 404
 405 static inline void free_part_info(struct hd_struct *part)
 406 {
 407         kfree(part->info);
 408 }
 409
 410 /* block/blk-core.c */
 411 extern void part_round_stats(int cpu, struct hd_struct *part);
 412
 413 /* block/genhd.c */
 414 extern void add_disk(struct gendisk *disk);
 415 extern void del_gendisk(struct gendisk *gp);
 416 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 417 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 418
 419 extern void set_device_ro(struct block_device *bdev, int flag);
 420 extern void set_disk_ro(struct gendisk *disk, int flag);
 421
 422 static inline int get_disk_ro(struct gendisk *disk)
 423 {
 424         return disk->part0.policy;
 425 }
 426
 427 extern void disk_block_events(struct gendisk *disk);
 428 extern void disk_unblock_events(struct gendisk *disk);
 429 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 430 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
 431
 432 /* drivers/char/random.c */
 433 extern void add_disk_randomness(struct gendisk *disk);
 434 extern void rand_initialize_disk(struct gendisk *disk);
 435
 436 static inline sector_t get_start_sect(struct block_device *bdev)
 437 {
 438         return bdev->bd_part->start_sect;
 439 }
 440 static inline sector_t get_capacity(struct gendisk *disk)
 441 {
 442         return disk->part0.nr_sects;
 443 }
 444 static inline void set_capacity(struct gendisk *disk, sector_t size)
 445 {
 446         disk->part0.nr_sects = size;
 447 }
 448
 449 #ifdef CONFIG_SOLARIS_X86_PARTITION
 450
 451 #define SOLARIS_X86_NUMSLICE    16
 452 #define SOLARIS_X86_VTOC_SANE   (0x600DDEEEUL)
 453
 454 struct solaris_x86_slice {
 455         __le16 s_tag;           /* ID tag of partition */
 456         __le16 s_flag;          /* permission flags */
 457         __le32 s_start;         /* start sector no of partition */
 458         __le32 s_size;          /* # of blocks in partition */
 459 };
 460
 461 struct solaris_x86_vtoc {
 462         unsigned int v_bootinfo[3];     /* info needed by mboot (unsupported) */
 463         __le32 v_sanity;                /* to verify vtoc sanity */
 464         __le32 v_version;               /* layout version */
 465         char    v_volume[8];            /* volume name */
 466         __le16  v_sectorsz;             /* sector size in bytes */
 467         __le16  v_nparts;               /* number of partitions */
 468         unsigned int v_reserved[10];    /* free space */
 469         struct solaris_x86_slice
 470                 v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
 471         unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
 472         char    v_asciilabel[128];      /* for compatibility */
 473 };
 474
 475 #endif /* CONFIG_SOLARIS_X86_PARTITION */
 476
 477 #ifdef CONFIG_BSD_DISKLABEL
 478 /*
 479  * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
 480  * updated by Marc Espie <Marc.Espie@openbsd.org>
 481  */
 482
 483 /* check against BSD src/sys/sys/disklabel.h for consistency */
 484
 485 #define BSD_DISKMAGIC   (0x82564557UL)  /* The disk magic number */
 486 #define BSD_MAXPARTITIONS       16
 487 #define OPENBSD_MAXPARTITIONS   16
 488 #define BSD_FS_UNUSED           0       /* disklabel unused partition entry ID */
 489 struct bsd_disklabel {
 490         __le32  d_magic;                /* the magic number */
 491         __s16   d_type;                 /* drive type */
 492         __s16   d_subtype;              /* controller/d_type specific */
 493         char    d_typename[16];         /* type name, e.g. "eagle" */
 494         char    d_packname[16];                 /* pack identifier */
 495         __u32   d_secsize;              /* # of bytes per sector */
 496         __u32   d_nsectors;             /* # of data sectors per track */
 497         __u32   d_ntracks;              /* # of tracks per cylinder */
 498         __u32   d_ncylinders;           /* # of data cylinders per unit */
 499         __u32   d_secpercyl;            /* # of data sectors per cylinder */
 500         __u32   d_secperunit;           /* # of data sectors per unit */
 501         __u16   d_sparespertrack;       /* # of spare sectors per track */
 502         __u16   d_sparespercyl;         /* # of spare sectors per cylinder */
 503         __u32   d_acylinders;           /* # of alt. cylinders per unit */
 504         __u16   d_rpm;                  /* rotational speed */
 505         __u16   d_interleave;           /* hardware sector interleave */
 506         __u16   d_trackskew;            /* sector 0 skew, per track */
 507         __u16   d_cylskew;              /* sector 0 skew, per cylinder */
 508         __u32   d_headswitch;           /* head switch time, usec */
 509         __u32   d_trkseek;              /* track-to-track seek, usec */
 510         __u32   d_flags;                /* generic flags */
 511 #define NDDATA 5
 512         __u32   d_drivedata[NDDATA];    /* drive-type specific information */
 513 #define NSPARE 5
 514         __u32   d_spare[NSPARE];        /* reserved for future use */
 515         __le32  d_magic2;               /* the magic number (again) */
 516         __le16  d_checksum;             /* xor of data incl. partitions */
 517
 518                         /* filesystem and partition information: */
 519         __le16  d_npartitions;          /* number of partitions in following */
 520         __le32  d_bbsize;               /* size of boot area at sn0, bytes */
 521         __le32  d_sbsize;               /* max size of fs superblock, bytes */
 522         struct  bsd_partition {         /* the partition table */
 523                 __le32  p_size;         /* number of sectors in partition */
 524                 __le32  p_offset;       /* starting sector */
 525                 __le32  p_fsize;        /* filesystem basic fragment size */
 526                 __u8    p_fstype;       /* filesystem type, see below */
 527                 __u8    p_frag;         /* filesystem fragments per block */
 528                 __le16  p_cpg;          /* filesystem cylinders per group */
 529         } d_partitions[BSD_MAXPARTITIONS];      /* actually may be more */
 530 };
 531
 532 #endif  /* CONFIG_BSD_DISKLABEL */
 533
 534 #ifdef CONFIG_UNIXWARE_DISKLABEL
 535 /*
 536  * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
 537  * and Krzysztof G. Baranowski <kgb@knm.org.pl>
 538  */
 539
 540 #define UNIXWARE_DISKMAGIC     (0xCA5E600DUL)   /* The disk magic number */
 541 #define UNIXWARE_DISKMAGIC2    (0x600DDEEEUL)   /* The slice table magic nr */
 542 #define UNIXWARE_NUMSLICE      16
 543 #define UNIXWARE_FS_UNUSED     0                /* Unused slice entry ID */
 544
 545 struct unixware_slice {
 546         __le16   s_label;       /* label */
 547         __le16   s_flags;       /* permission flags */
 548         __le32   start_sect;    /* starting sector */
 549         __le32   nr_sects;      /* number of sectors in slice */
 550 };
 551
 552 struct unixware_disklabel {
 553         __le32   d_type;                /* drive type */
 554         __le32   d_magic;                /* the magic number */
 555         __le32   d_version;              /* version number */
 556         char    d_serial[12];           /* serial number of the device */
 557         __le32   d_ncylinders;           /* # of data cylinders per device */
 558         __le32   d_ntracks;              /* # of tracks per cylinder */
 559         __le32   d_nsectors;             /* # of data sectors per track */
 560         __le32   d_secsize;              /* # of bytes per sector */
 561         __le32   d_part_start;           /* # of first sector of this partition */
 562         __le32   d_unknown1[12];         /* ? */
 563         __le32  d_alt_tbl;              /* byte offset of alternate table */
 564         __le32  d_alt_len;              /* byte length of alternate table */
 565         __le32  d_phys_cyl;             /* # of physical cylinders per device */
 566         __le32  d_phys_trk;             /* # of physical tracks per cylinder */
 567         __le32  d_phys_sec;             /* # of physical sectors per track */
 568         __le32  d_phys_bytes;           /* # of physical bytes per sector */
 569         __le32  d_unknown2;             /* ? */
 570         __le32   d_unknown3;             /* ? */
 571         __le32  d_pad[8];               /* pad */
 572
 573         struct unixware_vtoc {
 574                 __le32  v_magic;                /* the magic number */
 575                 __le32  v_version;              /* version number */
 576                 char    v_name[8];              /* volume name */
 577                 __le16  v_nslices;              /* # of slices */
 578                 __le16  v_unknown1;             /* ? */
 579                 __le32  v_reserved[10];         /* reserved */
 580                 struct unixware_slice
 581                         v_slice[UNIXWARE_NUMSLICE];     /* slice headers */
 582         } vtoc;
 583
 584 };  /* 408 */
 585
 586 #endif /* CONFIG_UNIXWARE_DISKLABEL */
 587
 588 #ifdef CONFIG_MINIX_SUBPARTITION
 589 #   define MINIX_NR_SUBPARTITIONS  4
 590 #endif /* CONFIG_MINIX_SUBPARTITION */
 591
 592 #define ADDPART_FLAG_NONE       0
 593 #define ADDPART_FLAG_RAID       1
 594 #define ADDPART_FLAG_WHOLEDISK  2
 595
 596 extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
 597 extern void blk_free_devt(dev_t devt);
 598 extern dev_t blk_lookup_devt(const char *name, int partno);
 599 extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 600
 601 extern int disk_expand_part_tbl(struct gendisk *disk, int target);
 602 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
 603 extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
 604                                                      int partno, sector_t start,
 605                                                      sector_t len, int flags,
 606                                                      struct partition_meta_info
 607                                                        *info);
 608 extern void __delete_partition(struct hd_struct *);
 609 extern void delete_partition(struct gendisk *, int);
 610 extern void printk_all_partitions(void);
 611
 612 extern struct gendisk *alloc_disk_node(int minors, int node_id);
 613 extern struct gendisk *alloc_disk(int minors);
 614 extern struct kobject *get_disk(struct gendisk *disk);
 615 extern void put_disk(struct gendisk *disk);
 616 extern void blk_register_region(dev_t devt, unsigned long range,
 617                         struct module *module,
 618                         struct kobject *(*probe)(dev_t, int *, void *),
 619                         int (*lock)(dev_t, void *),
 620                         void *data);
 621 extern void blk_unregister_region(dev_t devt, unsigned long range);
 622
 623 extern ssize_t part_size_show(struct device *dev,
 624                               struct device_attribute *attr, char *buf);
 625 extern ssize_t part_stat_show(struct device *dev,
 626                               struct device_attribute *attr, char *buf);
 627 extern ssize_t part_inflight_show(struct device *dev,
 628                               struct device_attribute *attr, char *buf);
 629 #ifdef CONFIG_FAIL_MAKE_REQUEST
 630 extern ssize_t part_fail_show(struct device *dev,
 631                               struct device_attribute *attr, char *buf);
 632 extern ssize_t part_fail_store(struct device *dev,
 633                                struct device_attribute *attr,
 634                                const char *buf, size_t count);
 635 #endif /* CONFIG_FAIL_MAKE_REQUEST */
 636
 637 static inline void hd_ref_init(struct hd_struct *part)
 638 {
 639         atomic_set(&part->ref, 1);
 640         smp_mb();
 641 }
 642
 643 static inline void hd_struct_get(struct hd_struct *part)
 644 {
 645         atomic_inc(&part->ref);
 646         smp_mb__after_atomic_inc();
 647 }
 648
 649 static inline int hd_struct_try_get(struct hd_struct *part)
 650 {
 651         return atomic_inc_not_zero(&part->ref);
 652 }
 653
 654 static inline void hd_struct_put(struct hd_struct *part)
 655 {
 656         if (atomic_dec_and_test(&part->ref))
 657                 __delete_partition(part);
 658 }
 659
 660 #else /* CONFIG_BLOCK */
 661
 662 static inline void printk_all_partitions(void) { }
 663
 664 static inline dev_t blk_lookup_devt(const char *name, int partno)
 665 {
 666         dev_t devt = MKDEV(0, 0);
 667         return devt;
 668 }
 669
 670 #endif /* CONFIG_BLOCK */
 671
 672 #endif /* _LINUX_GENHD_H */