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 dev_to_disk(device)     container_of((device), struct gendisk, part0.__dev)
  20 #define dev_to_part(device)     container_of((device), struct hd_struct, __dev)
  21 #define disk_to_dev(disk)       (&(disk)->part0.__dev)
  22 #define part_to_dev(part)       (&((part)->__dev))
  23
  24 extern struct device_type part_type;
  25 extern struct kobject *block_depr;
  26 extern struct class block_class;
  27
  28 enum {
  29 /* These three have identical behaviour; use the second one if DOS FDISK gets
  30    confused about extended/logical partitions starting past cylinder 1023. */
  31         DOS_EXTENDED_PARTITION = 5,
  32         LINUX_EXTENDED_PARTITION = 0x85,
  33         WIN98_EXTENDED_PARTITION = 0x0f,
  34
  35         SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
  36
  37         LINUX_SWAP_PARTITION = 0x82,
  38         LINUX_DATA_PARTITION = 0x83,
  39         LINUX_LVM_PARTITION = 0x8e,
  40         LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
  41
  42         SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
  43         NEW_SOLARIS_X86_PARTITION = 0xbf,
  44
  45         DM6_AUX1PARTITION = 0x51,       /* no DDO:  use xlated geom */
  46         DM6_AUX3PARTITION = 0x53,       /* no DDO:  use xlated geom */
  47         DM6_PARTITION = 0x54,           /* has DDO: use xlated geom & offset */
  48         EZD_PARTITION = 0x55,           /* EZ-DRIVE */
  49
  50         FREEBSD_PARTITION = 0xa5,       /* FreeBSD Partition ID */
  51         OPENBSD_PARTITION = 0xa6,       /* OpenBSD Partition ID */
  52         NETBSD_PARTITION = 0xa9,        /* NetBSD Partition ID */
  53         BSDI_PARTITION = 0xb7,          /* BSDI Partition ID */
  54         MINIX_PARTITION = 0x81,         /* Minix Partition ID */
  55         UNIXWARE_PARTITION = 0x63,      /* Same as GNU_HURD and SCO Unix */
  56 };
  57
  58 #define DISK_MAX_PARTS                  256
  59 #define DISK_NAME_LEN                   32
  60
  61 #include <linux/major.h>
  62 #include <linux/device.h>
  63 #include <linux/smp.h>
  64 #include <linux/string.h>
  65 #include <linux/fs.h>
  66 #include <linux/workqueue.h>
  67
  68 struct partition {
  69         unsigned char boot_ind;         /* 0x80 - active */
  70         unsigned char head;             /* starting head */
  71         unsigned char sector;           /* starting sector */
  72         unsigned char cyl;              /* starting cylinder */
  73         unsigned char sys_ind;          /* What partition type */
  74         unsigned char end_head;         /* end head */
  75         unsigned char end_sector;       /* end sector */
  76         unsigned char end_cyl;          /* end cylinder */
  77         __le32 start_sect;      /* starting sector counting from 0 */
  78         __le32 nr_sects;                /* nr of sectors in partition */
  79 } __attribute__((packed));
  80
  81 struct disk_stats {
  82         unsigned long sectors[2];       /* READs and WRITEs */
  83         unsigned long ios[2];
  84         unsigned long merges[2];
  85         unsigned long ticks[2];
  86         unsigned long io_ticks;
  87         unsigned long time_in_queue;
  88 };
  89
  90 #define PARTITION_META_INFO_VOLNAMELTH  64
  91 /*
  92  * Enough for the string representation of any kind of UUID plus NULL.
  93  * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
  94  */
  95 #define PARTITION_META_INFO_UUIDLTH     37
  96
  97 struct partition_meta_info {
  98         char uuid[PARTITION_META_INFO_UUIDLTH];
  99         u8 volname[PARTITION_META_INFO_VOLNAMELTH];
 100 };
 101
 102 struct hd_struct {
 103         sector_t start_sect;
 104         /*
 105          * nr_sects is protected by sequence counter. One might extend a
 106          * partition while IO is happening to it and update of nr_sects
 107          * can be non-atomic on 32bit machines with 64bit sector_t.
 108          */
 109         sector_t nr_sects;
 110         seqcount_t nr_sects_seq;
 111         sector_t alignment_offset;
 112         unsigned int discard_alignment;
 113         struct device __dev;
 114         struct kobject *holder_dir;
 115         int policy, partno;
 116         struct partition_meta_info *info;
 117 #ifdef CONFIG_FAIL_MAKE_REQUEST
 118         int make_it_fail;
 119 #endif
 120         unsigned long stamp;
 121         atomic_t in_flight[2];
 122 #ifdef  CONFIG_SMP
 123         struct disk_stats __percpu *dkstats;
 124 #else
 125         struct disk_stats dkstats;
 126 #endif
 127         atomic_t ref;
 128         struct rcu_head rcu_head;
 129 };
 130
 131 #define GENHD_FL_REMOVABLE                      1
 132 /* 2 is unused */
 133 #define GENHD_FL_MEDIA_CHANGE_NOTIFY            4
 134 #define GENHD_FL_CD                             8
 135 #define GENHD_FL_UP                             16
 136 #define GENHD_FL_SUPPRESS_PARTITION_INFO        32
 137 #define GENHD_FL_EXT_DEVT                       64 /* allow extended devt */
 138 #define GENHD_FL_NATIVE_CAPACITY                128
 139 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE     256
 140 #define GENHD_FL_NO_PART_SCAN                   512
 141
 142 enum {
 143         DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 144         DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 145 };
 146
 147 #define BLK_SCSI_MAX_CMDS       (256)
 148 #define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 149
 150 struct blk_scsi_cmd_filter {
 151         unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
 152         unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
 153         struct kobject kobj;
 154 };
 155
 156 struct disk_part_tbl {
 157         struct rcu_head rcu_head;
 158         int len;
 159         struct hd_struct __rcu *last_lookup;
 160         struct hd_struct __rcu *part[];
 161 };
 162
 163 struct disk_events;
 164
 165 struct gendisk {
 166         /* major, first_minor and minors are input parameters only,
 167          * don't use directly.  Use disk_devt() and disk_max_parts().
 168          */
 169         int major;                      /* major number of driver */
 170         int first_minor;
 171         int minors;                     /* maximum number of minors, =1 for
 172                                          * disks that can't be partitioned. */
 173
 174         char disk_name[DISK_NAME_LEN];  /* name of major driver */
 175         char *(*devnode)(struct gendisk *gd, umode_t *mode);
 176
 177         unsigned int events;            /* supported events */
 178         unsigned int async_events;      /* async events, subset of all */
 179
 180         /* Array of pointers to partitions indexed by partno.
 181          * Protected with matching bdev lock but stat and other
 182          * non-critical accesses use RCU.  Always access through
 183          * helpers.
 184          */
 185         struct disk_part_tbl __rcu *part_tbl;
 186         struct hd_struct part0;
 187
 188         const struct block_device_operations *fops;
 189         struct request_queue *queue;
 190         void *private_data;
 191
 192         int flags;
 193         struct device *driverfs_dev;  // FIXME: remove
 194         struct kobject *slave_dir;
 195
 196         struct timer_rand_state *random;
 197         atomic_t sync_io;               /* RAID */
 198         struct disk_events *ev;
 199 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 200         struct blk_integrity *integrity;
 201 #endif
 202         int node_id;
 203 };
 204
 205 static inline struct gendisk *part_to_disk(struct hd_struct *part)
 206 {
 207         if (likely(part)) {
 208                 if (part->partno)
 209                         return dev_to_disk(part_to_dev(part)->parent);
 210                 else
 211                         return dev_to_disk(part_to_dev(part));
 212         }
 213         return NULL;
 214 }
 215
 216 static inline void part_pack_uuid(const u8 *uuid_str, u8 *to)
 217 {
 218         int i;
 219         for (i = 0; i < 16; ++i) {
 220                 *to++ = (hex_to_bin(*uuid_str) << 4) |
 221                         (hex_to_bin(*(uuid_str + 1)));
 222                 uuid_str += 2;
 223                 switch (i) {
 224                 case 3:
 225                 case 5:
 226                 case 7:
 227                 case 9:
 228                         uuid_str++;
 229                         continue;
 230                 }
 231         }
 232 }
 233
 234 static inline int disk_max_parts(struct gendisk *disk)
 235 {
 236         if (disk->flags & GENHD_FL_EXT_DEVT)
 237                 return DISK_MAX_PARTS;
 238         return disk->minors;
 239 }
 240
 241 static inline bool disk_part_scan_enabled(struct gendisk *disk)
 242 {
 243         return disk_max_parts(disk) > 1 &&
 244                 !(disk->flags & GENHD_FL_NO_PART_SCAN);
 245 }
 246
 247 static inline dev_t disk_devt(struct gendisk *disk)
 248 {
 249         return disk_to_dev(disk)->devt;
 250 }
 251
 252 static inline dev_t part_devt(struct hd_struct *part)
 253 {
 254         return part_to_dev(part)->devt;
 255 }
 256
 257 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 258
 259 static inline void disk_put_part(struct hd_struct *part)
 260 {
 261         if (likely(part))
 262                 put_device(part_to_dev(part));
 263 }
 264
 265 /*
 266  * Smarter partition iterator without context limits.
 267  */
 268 #define DISK_PITER_REVERSE      (1 << 0) /* iterate in the reverse direction */
 269 #define DISK_PITER_INCL_EMPTY   (1 << 1) /* include 0-sized parts */
 270 #define DISK_PITER_INCL_PART0   (1 << 2) /* include partition 0 */
 271 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
 272
 273 struct disk_part_iter {
 274         struct gendisk          *disk;
 275         struct hd_struct        *part;
 276         int                     idx;
 277         unsigned int            flags;
 278 };
 279
 280 extern void disk_part_iter_init(struct disk_part_iter *piter,
 281                                  struct gendisk *disk, unsigned int flags);
 282 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 283 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 284
 285 extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 286                                              sector_t sector);
 287
 288 /*
 289  * Macros to operate on percpu disk statistics:
 290  *
 291  * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 292  * and should be called between disk_stat_lock() and
 293  * disk_stat_unlock().
 294  *
 295  * part_stat_read() can be called at any time.
 296  *
 297  * part_stat_{add|set_all}() and {init|free}_part_stats are for
 298  * internal use only.
 299  */
 300 #ifdef  CONFIG_SMP
 301 #define part_stat_lock()        ({ rcu_read_lock(); get_cpu(); })
 302 #define part_stat_unlock()      do { put_cpu(); rcu_read_unlock(); } while (0)
 303
 304 #define __part_stat_add(cpu, part, field, addnd)                        \
 305         (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
 306
 307 #define part_stat_read(part, field)                                     \
 308 ({                                                                      \
 309         typeof((part)->dkstats->field) res = 0;                         \
 310         unsigned int _cpu;                                              \
 311         for_each_possible_cpu(_cpu)                                     \
 312                 res += per_cpu_ptr((part)->dkstats, _cpu)->field;       \
 313         res;                                                            \
 314 })
 315
 316 static inline void part_stat_set_all(struct hd_struct *part, int value)
 317 {
 318         int i;
 319
 320         for_each_possible_cpu(i)
 321                 memset(per_cpu_ptr(part->dkstats, i), value,
 322                                 sizeof(struct disk_stats));
 323 }
 324
 325 static inline int init_part_stats(struct hd_struct *part)
 326 {
 327         part->dkstats = alloc_percpu(struct disk_stats);
 328         if (!part->dkstats)
 329                 return 0;
 330         return 1;
 331 }
 332
 333 static inline void free_part_stats(struct hd_struct *part)
 334 {
 335         free_percpu(part->dkstats);
 336 }
 337
 338 #else /* !CONFIG_SMP */
 339 #define part_stat_lock()        ({ rcu_read_lock(); 0; })
 340 #define part_stat_unlock()      rcu_read_unlock()
 341
 342 #define __part_stat_add(cpu, part, field, addnd)                                \
 343         ((part)->dkstats.field += addnd)
 344
 345 #define part_stat_read(part, field)     ((part)->dkstats.field)
 346
 347 static inline void part_stat_set_all(struct hd_struct *part, int value)
 348 {
 349         memset(&part->dkstats, value, sizeof(struct disk_stats));
 350 }
 351
 352 static inline int init_part_stats(struct hd_struct *part)
 353 {
 354         return 1;
 355 }
 356
 357 static inline void free_part_stats(struct hd_struct *part)
 358 {
 359 }
 360
 361 #endif /* CONFIG_SMP */
 362
 363 #define part_stat_add(cpu, part, field, addnd)  do {                    \
 364         __part_stat_add((cpu), (part), field, addnd);                   \
 365         if ((part)->partno)                                             \
 366                 __part_stat_add((cpu), &part_to_disk((part))->part0,    \
 367                                 field, addnd);                          \
 368 } while (0)
 369
 370 #define part_stat_dec(cpu, gendiskp, field)                             \
 371         part_stat_add(cpu, gendiskp, field, -1)
 372 #define part_stat_inc(cpu, gendiskp, field)                             \
 373         part_stat_add(cpu, gendiskp, field, 1)
 374 #define part_stat_sub(cpu, gendiskp, field, subnd)                      \
 375         part_stat_add(cpu, gendiskp, field, -subnd)
 376
 377 static inline void part_inc_in_flight(struct hd_struct *part, int rw)
 378 {
 379         atomic_inc(&part->in_flight[rw]);
 380         if (part->partno)
 381                 atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
 382 }
 383
 384 static inline void part_dec_in_flight(struct hd_struct *part, int rw)
 385 {
 386         atomic_dec(&part->in_flight[rw]);
 387         if (part->partno)
 388                 atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
 389 }
 390
 391 static inline int part_in_flight(struct hd_struct *part)
 392 {
 393         return atomic_read(&part->in_flight[0]) + atomic_read(&part->in_flight[1]);
 394 }
 395
 396 static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
 397 {
 398         if (disk)
 399                 return kzalloc_node(sizeof(struct partition_meta_info),
 400                                     GFP_KERNEL, disk->node_id);
 401         return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
 402 }
 403
 404 static inline void free_part_info(struct hd_struct *part)
 405 {
 406         kfree(part->info);
 407 }
 408
 409 /* block/blk-core.c */
 410 extern void part_round_stats(int cpu, struct hd_struct *part);
 411
 412 /* block/genhd.c */
 413 extern void add_disk(struct gendisk *disk);
 414 extern void del_gendisk(struct gendisk *gp);
 415 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 416 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 417
 418 extern void set_device_ro(struct block_device *bdev, int flag);
 419 extern void set_disk_ro(struct gendisk *disk, int flag);
 420
 421 static inline int get_disk_ro(struct gendisk *disk)
 422 {
 423         return disk->part0.policy;
 424 }
 425
 426 extern void disk_block_events(struct gendisk *disk);
 427 extern void disk_unblock_events(struct gendisk *disk);
 428 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 429 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
 430
 431 /* drivers/char/random.c */
 432 extern void add_disk_randomness(struct gendisk *disk);
 433 extern void rand_initialize_disk(struct gendisk *disk);
 434
 435 static inline sector_t get_start_sect(struct block_device *bdev)
 436 {
 437         return bdev->bd_part->start_sect;
 438 }
 439 static inline sector_t get_capacity(struct gendisk *disk)
 440 {
 441         return disk->part0.nr_sects;
 442 }
 443 static inline void set_capacity(struct gendisk *disk, sector_t size)
 444 {
 445         disk->part0.nr_sects = size;
 446 }
 447
 448 #ifdef CONFIG_SOLARIS_X86_PARTITION
 449
 450 #define SOLARIS_X86_NUMSLICE    16
 451 #define SOLARIS_X86_VTOC_SANE   (0x600DDEEEUL)
 452
 453 struct solaris_x86_slice {
 454         __le16 s_tag;           /* ID tag of partition */
 455         __le16 s_flag;          /* permission flags */
 456         __le32 s_start;         /* start sector no of partition */
 457         __le32 s_size;          /* # of blocks in partition */
 458 };
 459
 460 struct solaris_x86_vtoc {
 461         unsigned int v_bootinfo[3];     /* info needed by mboot (unsupported) */
 462         __le32 v_sanity;                /* to verify vtoc sanity */
 463         __le32 v_version;               /* layout version */
 464         char    v_volume[8];            /* volume name */
 465         __le16  v_sectorsz;             /* sector size in bytes */
 466         __le16  v_nparts;               /* number of partitions */
 467         unsigned int v_reserved[10];    /* free space */
 468         struct solaris_x86_slice
 469                 v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
 470         unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
 471         char    v_asciilabel[128];      /* for compatibility */
 472 };
 473
 474 #endif /* CONFIG_SOLARIS_X86_PARTITION */
 475
 476 #ifdef CONFIG_BSD_DISKLABEL
 477 /*
 478  * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
 479  * updated by Marc Espie <Marc.Espie@openbsd.org>
 480  */
 481
 482 /* check against BSD src/sys/sys/disklabel.h for consistency */
 483
 484 #define BSD_DISKMAGIC   (0x82564557UL)  /* The disk magic number */
 485 #define BSD_MAXPARTITIONS       16
 486 #define OPENBSD_MAXPARTITIONS   16
 487 #define BSD_FS_UNUSED           0       /* disklabel unused partition entry ID */
 488 struct bsd_disklabel {
 489         __le32  d_magic;                /* the magic number */
 490         __s16   d_type;                 /* drive type */
 491         __s16   d_subtype;              /* controller/d_type specific */
 492         char    d_typename[16];         /* type name, e.g. "eagle" */
 493         char    d_packname[16];                 /* pack identifier */
 494         __u32   d_secsize;              /* # of bytes per sector */
 495         __u32   d_nsectors;             /* # of data sectors per track */
 496         __u32   d_ntracks;              /* # of tracks per cylinder */
 497         __u32   d_ncylinders;           /* # of data cylinders per unit */
 498         __u32   d_secpercyl;            /* # of data sectors per cylinder */
 499         __u32   d_secperunit;           /* # of data sectors per unit */
 500         __u16   d_sparespertrack;       /* # of spare sectors per track */
 501         __u16   d_sparespercyl;         /* # of spare sectors per cylinder */
 502         __u32   d_acylinders;           /* # of alt. cylinders per unit */
 503         __u16   d_rpm;                  /* rotational speed */
 504         __u16   d_interleave;           /* hardware sector interleave */
 505         __u16   d_trackskew;            /* sector 0 skew, per track */
 506         __u16   d_cylskew;              /* sector 0 skew, per cylinder */
 507         __u32   d_headswitch;           /* head switch time, usec */
 508         __u32   d_trkseek;              /* track-to-track seek, usec */
 509         __u32   d_flags;                /* generic flags */
 510 #define NDDATA 5
 511         __u32   d_drivedata[NDDATA];    /* drive-type specific information */
 512 #define NSPARE 5
 513         __u32   d_spare[NSPARE];        /* reserved for future use */
 514         __le32  d_magic2;               /* the magic number (again) */
 515         __le16  d_checksum;             /* xor of data incl. partitions */
 516
 517                         /* filesystem and partition information: */
 518         __le16  d_npartitions;          /* number of partitions in following */
 519         __le32  d_bbsize;               /* size of boot area at sn0, bytes */
 520         __le32  d_sbsize;               /* max size of fs superblock, bytes */
 521         struct  bsd_partition {         /* the partition table */
 522                 __le32  p_size;         /* number of sectors in partition */
 523                 __le32  p_offset;       /* starting sector */
 524                 __le32  p_fsize;        /* filesystem basic fragment size */
 525                 __u8    p_fstype;       /* filesystem type, see below */
 526                 __u8    p_frag;         /* filesystem fragments per block */
 527                 __le16  p_cpg;          /* filesystem cylinders per group */
 528         } d_partitions[BSD_MAXPARTITIONS];      /* actually may be more */
 529 };
 530
 531 #endif  /* CONFIG_BSD_DISKLABEL */
 532
 533 #ifdef CONFIG_UNIXWARE_DISKLABEL
 534 /*
 535  * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
 536  * and Krzysztof G. Baranowski <kgb@knm.org.pl>
 537  */
 538
 539 #define UNIXWARE_DISKMAGIC     (0xCA5E600DUL)   /* The disk magic number */
 540 #define UNIXWARE_DISKMAGIC2    (0x600DDEEEUL)   /* The slice table magic nr */
 541 #define UNIXWARE_NUMSLICE      16
 542 #define UNIXWARE_FS_UNUSED     0                /* Unused slice entry ID */
 543
 544 struct unixware_slice {
 545         __le16   s_label;       /* label */
 546         __le16   s_flags;       /* permission flags */
 547         __le32   start_sect;    /* starting sector */
 548         __le32   nr_sects;      /* number of sectors in slice */
 549 };
 550
 551 struct unixware_disklabel {
 552         __le32   d_type;                /* drive type */
 553         __le32   d_magic;                /* the magic number */
 554         __le32   d_version;              /* version number */
 555         char    d_serial[12];           /* serial number of the device */
 556         __le32   d_ncylinders;           /* # of data cylinders per device */
 557         __le32   d_ntracks;              /* # of tracks per cylinder */
 558         __le32   d_nsectors;             /* # of data sectors per track */
 559         __le32   d_secsize;              /* # of bytes per sector */
 560         __le32   d_part_start;           /* # of first sector of this partition */
 561         __le32   d_unknown1[12];         /* ? */
 562         __le32  d_alt_tbl;              /* byte offset of alternate table */
 563         __le32  d_alt_len;              /* byte length of alternate table */
 564         __le32  d_phys_cyl;             /* # of physical cylinders per device */
 565         __le32  d_phys_trk;             /* # of physical tracks per cylinder */
 566         __le32  d_phys_sec;             /* # of physical sectors per track */
 567         __le32  d_phys_bytes;           /* # of physical bytes per sector */
 568         __le32  d_unknown2;             /* ? */
 569         __le32   d_unknown3;             /* ? */
 570         __le32  d_pad[8];               /* pad */
 571
 572         struct unixware_vtoc {
 573                 __le32  v_magic;                /* the magic number */
 574                 __le32  v_version;              /* version number */
 575                 char    v_name[8];              /* volume name */
 576                 __le16  v_nslices;              /* # of slices */
 577                 __le16  v_unknown1;             /* ? */
 578                 __le32  v_reserved[10];         /* reserved */
 579                 struct unixware_slice
 580                         v_slice[UNIXWARE_NUMSLICE];     /* slice headers */
 581         } vtoc;
 582
 583 };  /* 408 */
 584
 585 #endif /* CONFIG_UNIXWARE_DISKLABEL */
 586
 587 #ifdef CONFIG_MINIX_SUBPARTITION
 588 #   define MINIX_NR_SUBPARTITIONS  4
 589 #endif /* CONFIG_MINIX_SUBPARTITION */
 590
 591 #define ADDPART_FLAG_NONE       0
 592 #define ADDPART_FLAG_RAID       1
 593 #define ADDPART_FLAG_WHOLEDISK  2
 594
 595 extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
 596 extern void blk_free_devt(dev_t devt);
 597 extern dev_t blk_lookup_devt(const char *name, int partno);
 598 extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 599
 600 extern int disk_expand_part_tbl(struct gendisk *disk, int target);
 601 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
 602 extern int invalidate_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 /*
 661  * Any access of part->nr_sects which is not protected by partition
 662  * bd_mutex or gendisk bdev bd_mutex, should be done using this
 663  * accessor function.
 664  *
 665  * Code written along the lines of i_size_read() and i_size_write().
 666  * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption
 667  * on.
 668  */
 669 static inline sector_t part_nr_sects_read(struct hd_struct *part)
 670 {
 671 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
 672         sector_t nr_sects;
 673         unsigned seq;
 674         do {
 675                 seq = read_seqcount_begin(&part->nr_sects_seq);
 676                 nr_sects = part->nr_sects;
 677         } while (read_seqcount_retry(&part->nr_sects_seq, seq));
 678         return nr_sects;
 679 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
 680         sector_t nr_sects;
 681
 682         preempt_disable();
 683         nr_sects = part->nr_sects;
 684         preempt_enable();
 685         return nr_sects;
 686 #else
 687         return part->nr_sects;
 688 #endif
 689 }
 690
 691 /*
 692  * Should be called with mutex lock held (typically bd_mutex) of partition
 693  * to provide mutual exlusion among writers otherwise seqcount might be
 694  * left in wrong state leaving the readers spinning infinitely.
 695  */
 696 static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
 697 {
 698 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
 699         write_seqcount_begin(&part->nr_sects_seq);
 700         part->nr_sects = size;
 701         write_seqcount_end(&part->nr_sects_seq);
 702 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
 703         preempt_disable();
 704         part->nr_sects = size;
 705         preempt_enable();
 706 #else
 707         part->nr_sects = size;
 708 #endif
 709 }
 710
 711 #else /* CONFIG_BLOCK */
 712
 713 static inline void printk_all_partitions(void) { }
 714
 715 static inline dev_t blk_lookup_devt(const char *name, int partno)
 716 {
 717         dev_t devt = MKDEV(0, 0);
 718         return devt;
 719 }
 720
 721 #endif /* CONFIG_BLOCK */
 722
 723 #endif /* _LINUX_GENHD_H */