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 #include <linux/percpu-refcount.h>
  17
  18 #ifdef CONFIG_BLOCK
  19
  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
  25 extern struct device_type part_type;
  26 extern struct kobject *block_depr;
  27 extern struct class block_class;
  28
  29 enum {
  30 /* These three have identical behaviour; use the second one if DOS FDISK gets
  31    confused about extended/logical partitions starting past cylinder 1023. */
  32         DOS_EXTENDED_PARTITION = 5,
  33         LINUX_EXTENDED_PARTITION = 0x85,
  34         WIN98_EXTENDED_PARTITION = 0x0f,
  35
  36         SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
  37
  38         LINUX_SWAP_PARTITION = 0x82,
  39         LINUX_DATA_PARTITION = 0x83,
  40         LINUX_LVM_PARTITION = 0x8e,
  41         LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
  42
  43         SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
  44         NEW_SOLARIS_X86_PARTITION = 0xbf,
  45
  46         DM6_AUX1PARTITION = 0x51,       /* no DDO:  use xlated geom */
  47         DM6_AUX3PARTITION = 0x53,       /* no DDO:  use xlated geom */
  48         DM6_PARTITION = 0x54,           /* has DDO: use xlated geom & offset */
  49         EZD_PARTITION = 0x55,           /* EZ-DRIVE */
  50
  51         FREEBSD_PARTITION = 0xa5,       /* FreeBSD Partition ID */
  52         OPENBSD_PARTITION = 0xa6,       /* OpenBSD Partition ID */
  53         NETBSD_PARTITION = 0xa9,        /* NetBSD Partition ID */
  54         BSDI_PARTITION = 0xb7,          /* BSDI Partition ID */
  55         MINIX_PARTITION = 0x81,         /* Minix Partition ID */
  56         UNIXWARE_PARTITION = 0x63,      /* Same as GNU_HURD and SCO Unix */
  57 };
  58
  59 #define DISK_MAX_PARTS                  256
  60 #define DISK_NAME_LEN                   32
  61
  62 #include <linux/major.h>
  63 #include <linux/device.h>
  64 #include <linux/smp.h>
  65 #include <linux/string.h>
  66 #include <linux/fs.h>
  67 #include <linux/workqueue.h>
  68
  69 struct partition {
  70         unsigned char boot_ind;         /* 0x80 - active */
  71         unsigned char head;             /* starting head */
  72         unsigned char sector;           /* starting sector */
  73         unsigned char cyl;              /* starting cylinder */
  74         unsigned char sys_ind;          /* What partition type */
  75         unsigned char end_head;         /* end head */
  76         unsigned char end_sector;       /* end sector */
  77         unsigned char end_cyl;          /* end cylinder */
  78         __le32 start_sect;      /* starting sector counting from 0 */
  79         __le32 nr_sects;                /* nr of sectors in partition */
  80 } __attribute__((packed));
  81
  82 struct disk_stats {
  83         unsigned long sectors[2];       /* READs and WRITEs */
  84         unsigned long ios[2];
  85         unsigned long merges[2];
  86         unsigned long ticks[2];
  87         unsigned long io_ticks;
  88         unsigned long time_in_queue;
  89 };
  90
  91 #define PARTITION_META_INFO_VOLNAMELTH  64
  92 /*
  93  * Enough for the string representation of any kind of UUID plus NULL.
  94  * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
  95  */
  96 #define PARTITION_META_INFO_UUIDLTH     37
  97
  98 struct partition_meta_info {
  99         char uuid[PARTITION_META_INFO_UUIDLTH];
 100         u8 volname[PARTITION_META_INFO_VOLNAMELTH];
 101 };
 102
 103 struct hd_struct {
 104         sector_t start_sect;
 105         /*
 106          * nr_sects is protected by sequence counter. One might extend a
 107          * partition while IO is happening to it and update of nr_sects
 108          * can be non-atomic on 32bit machines with 64bit sector_t.
 109          */
 110         sector_t nr_sects;
 111         seqcount_t nr_sects_seq;
 112         sector_t alignment_offset;
 113         unsigned int discard_alignment;
 114         struct device __dev;
 115         struct kobject *holder_dir;
 116         int policy, partno;
 117         struct partition_meta_info *info;
 118 #ifdef CONFIG_FAIL_MAKE_REQUEST
 119         int make_it_fail;
 120 #endif
 121         unsigned long stamp;
 122         atomic_t in_flight[2];
 123 #ifdef  CONFIG_SMP
 124         struct disk_stats __percpu *dkstats;
 125 #else
 126         struct disk_stats dkstats;
 127 #endif
 128         struct percpu_ref ref;
 129         struct rcu_head rcu_head;
 130 };
 131
 132 #define GENHD_FL_REMOVABLE                      1
 133 /* 2 is unused */
 134 #define GENHD_FL_MEDIA_CHANGE_NOTIFY            4
 135 #define GENHD_FL_CD                             8
 136 #define GENHD_FL_UP                             16
 137 #define GENHD_FL_SUPPRESS_PARTITION_INFO        32
 138 #define GENHD_FL_EXT_DEVT                       64 /* allow extended devt */
 139 #define GENHD_FL_NATIVE_CAPACITY                128
 140 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE     256
 141 #define GENHD_FL_NO_PART_SCAN                   512
 142
 143 enum {
 144         DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 145         DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 146 };
 147
 148 #define BLK_SCSI_MAX_CMDS       (256)
 149 #define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 150
 151 struct blk_scsi_cmd_filter {
 152         unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
 153         unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
 154         struct kobject kobj;
 155 };
 156
 157 struct disk_part_tbl {
 158         struct rcu_head rcu_head;
 159         int len;
 160         struct hd_struct __rcu *last_lookup;
 161         struct hd_struct __rcu *part[];
 162 };
 163
 164 struct disk_events;
 165
 166 struct gendisk {
 167         /* major, first_minor and minors are input parameters only,
 168          * don't use directly.  Use disk_devt() and disk_max_parts().
 169          */
 170         int major;                      /* major number of driver */
 171         int first_minor;
 172         int minors;                     /* maximum number of minors, =1 for
 173                                          * disks that can't be partitioned. */
 174
 175         char disk_name[DISK_NAME_LEN];  /* name of major driver */
 176         char *(*devnode)(struct gendisk *gd, umode_t *mode);
 177
 178         unsigned int events;            /* supported events */
 179         unsigned int async_events;      /* async events, subset of all */
 180
 181         /* Array of pointers to partitions indexed by partno.
 182          * Protected with matching bdev lock but stat and other
 183          * non-critical accesses use RCU.  Always access through
 184          * helpers.
 185          */
 186         struct disk_part_tbl __rcu *part_tbl;
 187         struct hd_struct part0;
 188
 189         const struct block_device_operations *fops;
 190         struct request_queue *queue;
 191         void *private_data;
 192
 193         int flags;
 194         struct device *driverfs_dev;  // FIXME: remove
 195         struct kobject *slave_dir;
 196
 197         struct timer_rand_state *random;
 198         atomic_t sync_io;               /* RAID */
 199         struct disk_events *ev;
 200 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 201         struct blk_integrity *integrity;
 202 #endif
 203         int node_id;
 204 };
 205
 206 static inline struct gendisk *part_to_disk(struct hd_struct *part)
 207 {
 208         if (likely(part)) {
 209                 if (part->partno)
 210                         return dev_to_disk(part_to_dev(part)->parent);
 211                 else
 212                         return dev_to_disk(part_to_dev(part));
 213         }
 214         return NULL;
 215 }
 216
 217 static inline void part_pack_uuid(const u8 *uuid_str, u8 *to)
 218 {
 219         int i;
 220         for (i = 0; i < 16; ++i) {
 221                 *to++ = (hex_to_bin(*uuid_str) << 4) |
 222                         (hex_to_bin(*(uuid_str + 1)));
 223                 uuid_str += 2;
 224                 switch (i) {
 225                 case 3:
 226                 case 5:
 227                 case 7:
 228                 case 9:
 229                         uuid_str++;
 230                         continue;
 231                 }
 232         }
 233 }
 234
 235 static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
 236 {
 237         part_pack_uuid(uuid_str, to);
 238         return 0;
 239 }
 240
 241 static inline int disk_max_parts(struct gendisk *disk)
 242 {
 243         if (disk->flags & GENHD_FL_EXT_DEVT)
 244                 return DISK_MAX_PARTS;
 245         return disk->minors;
 246 }
 247
 248 static inline bool disk_part_scan_enabled(struct gendisk *disk)
 249 {
 250         return disk_max_parts(disk) > 1 &&
 251                 !(disk->flags & GENHD_FL_NO_PART_SCAN);
 252 }
 253
 254 static inline dev_t disk_devt(struct gendisk *disk)
 255 {
 256         return disk_to_dev(disk)->devt;
 257 }
 258
 259 static inline dev_t part_devt(struct hd_struct *part)
 260 {
 261         return part_to_dev(part)->devt;
 262 }
 263
 264 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 265
 266 static inline void disk_put_part(struct hd_struct *part)
 267 {
 268         if (likely(part))
 269                 put_device(part_to_dev(part));
 270 }
 271
 272 /*
 273  * Smarter partition iterator without context limits.
 274  */
 275 #define DISK_PITER_REVERSE      (1 << 0) /* iterate in the reverse direction */
 276 #define DISK_PITER_INCL_EMPTY   (1 << 1) /* include 0-sized parts */
 277 #define DISK_PITER_INCL_PART0   (1 << 2) /* include partition 0 */
 278 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
 279
 280 struct disk_part_iter {
 281         struct gendisk          *disk;
 282         struct hd_struct        *part;
 283         int                     idx;
 284         unsigned int            flags;
 285 };
 286
 287 extern void disk_part_iter_init(struct disk_part_iter *piter,
 288                                  struct gendisk *disk, unsigned int flags);
 289 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 290 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 291
 292 extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 293                                              sector_t sector);
 294
 295 /*
 296  * Macros to operate on percpu disk statistics:
 297  *
 298  * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 299  * and should be called between disk_stat_lock() and
 300  * disk_stat_unlock().
 301  *
 302  * part_stat_read() can be called at any time.
 303  *
 304  * part_stat_{add|set_all}() and {init|free}_part_stats are for
 305  * internal use only.
 306  */
 307 #ifdef  CONFIG_SMP
 308 #define part_stat_lock()        ({ rcu_read_lock(); get_cpu(); })
 309 #define part_stat_unlock()      do { put_cpu(); rcu_read_unlock(); } while (0)
 310
 311 #define __part_stat_add(cpu, part, field, addnd)                        \
 312         (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
 313
 314 #define part_stat_read(part, field)                                     \
 315 ({                                                                      \
 316         typeof((part)->dkstats->field) res = 0;                         \
 317         unsigned int _cpu;                                              \
 318         for_each_possible_cpu(_cpu)                                     \
 319                 res += per_cpu_ptr((part)->dkstats, _cpu)->field;       \
 320         res;                                                            \
 321 })
 322
 323 static inline void part_stat_set_all(struct hd_struct *part, int value)
 324 {
 325         int i;
 326
 327         for_each_possible_cpu(i)
 328                 memset(per_cpu_ptr(part->dkstats, i), value,
 329                                 sizeof(struct disk_stats));
 330 }
 331
 332 static inline int init_part_stats(struct hd_struct *part)
 333 {
 334         part->dkstats = alloc_percpu(struct disk_stats);
 335         if (!part->dkstats)
 336                 return 0;
 337         return 1;
 338 }
 339
 340 static inline void free_part_stats(struct hd_struct *part)
 341 {
 342         free_percpu(part->dkstats);
 343 }
 344
 345 #else /* !CONFIG_SMP */
 346 #define part_stat_lock()        ({ rcu_read_lock(); 0; })
 347 #define part_stat_unlock()      rcu_read_unlock()
 348
 349 #define __part_stat_add(cpu, part, field, addnd)                                \
 350         ((part)->dkstats.field += addnd)
 351
 352 #define part_stat_read(part, field)     ((part)->dkstats.field)
 353
 354 static inline void part_stat_set_all(struct hd_struct *part, int value)
 355 {
 356         memset(&part->dkstats, value, sizeof(struct disk_stats));
 357 }
 358
 359 static inline int init_part_stats(struct hd_struct *part)
 360 {
 361         return 1;
 362 }
 363
 364 static inline void free_part_stats(struct hd_struct *part)
 365 {
 366 }
 367
 368 #endif /* CONFIG_SMP */
 369
 370 #define part_stat_add(cpu, part, field, addnd)  do {                    \
 371         __part_stat_add((cpu), (part), field, addnd);                   \
 372         if ((part)->partno)                                             \
 373                 __part_stat_add((cpu), &part_to_disk((part))->part0,    \
 374                                 field, addnd);                          \
 375 } while (0)
 376
 377 #define part_stat_dec(cpu, gendiskp, field)                             \
 378         part_stat_add(cpu, gendiskp, field, -1)
 379 #define part_stat_inc(cpu, gendiskp, field)                             \
 380         part_stat_add(cpu, gendiskp, field, 1)
 381 #define part_stat_sub(cpu, gendiskp, field, subnd)                      \
 382         part_stat_add(cpu, gendiskp, field, -subnd)
 383
 384 static inline void part_inc_in_flight(struct hd_struct *part, int rw)
 385 {
 386         atomic_inc(&part->in_flight[rw]);
 387         if (part->partno)
 388                 atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
 389 }
 390
 391 static inline void part_dec_in_flight(struct hd_struct *part, int rw)
 392 {
 393         atomic_dec(&part->in_flight[rw]);
 394         if (part->partno)
 395                 atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
 396 }
 397
 398 static inline int part_in_flight(struct hd_struct *part)
 399 {
 400         return atomic_read(&part->in_flight[0]) + atomic_read(&part->in_flight[1]);
 401 }
 402
 403 static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
 404 {
 405         if (disk)
 406                 return kzalloc_node(sizeof(struct partition_meta_info),
 407                                     GFP_KERNEL, disk->node_id);
 408         return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
 409 }
 410
 411 static inline void free_part_info(struct hd_struct *part)
 412 {
 413         kfree(part->info);
 414 }
 415
 416 /* block/blk-core.c */
 417 extern void part_round_stats(int cpu, struct hd_struct *part);
 418
 419 /* block/genhd.c */
 420 extern void add_disk(struct gendisk *disk);
 421 extern void del_gendisk(struct gendisk *gp);
 422 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 423 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 424
 425 extern void set_device_ro(struct block_device *bdev, int flag);
 426 extern void set_disk_ro(struct gendisk *disk, int flag);
 427
 428 static inline int get_disk_ro(struct gendisk *disk)
 429 {
 430         return disk->part0.policy;
 431 }
 432
 433 extern void disk_block_events(struct gendisk *disk);
 434 extern void disk_unblock_events(struct gendisk *disk);
 435 extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
 436 extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
 437
 438 /* drivers/char/random.c */
 439 extern void add_disk_randomness(struct gendisk *disk);
 440 extern void rand_initialize_disk(struct gendisk *disk);
 441
 442 static inline sector_t get_start_sect(struct block_device *bdev)
 443 {
 444         return bdev->bd_part->start_sect;
 445 }
 446 static inline sector_t get_capacity(struct gendisk *disk)
 447 {
 448         return disk->part0.nr_sects;
 449 }
 450 static inline void set_capacity(struct gendisk *disk, sector_t size)
 451 {
 452         disk->part0.nr_sects = size;
 453 }
 454
 455 #ifdef CONFIG_SOLARIS_X86_PARTITION
 456
 457 #define SOLARIS_X86_NUMSLICE    16
 458 #define SOLARIS_X86_VTOC_SANE   (0x600DDEEEUL)
 459
 460 struct solaris_x86_slice {
 461         __le16 s_tag;           /* ID tag of partition */
 462         __le16 s_flag;          /* permission flags */
 463         __le32 s_start;         /* start sector no of partition */
 464         __le32 s_size;          /* # of blocks in partition */
 465 };
 466
 467 struct solaris_x86_vtoc {
 468         unsigned int v_bootinfo[3];     /* info needed by mboot (unsupported) */
 469         __le32 v_sanity;                /* to verify vtoc sanity */
 470         __le32 v_version;               /* layout version */
 471         char    v_volume[8];            /* volume name */
 472         __le16  v_sectorsz;             /* sector size in bytes */
 473         __le16  v_nparts;               /* number of partitions */
 474         unsigned int v_reserved[10];    /* free space */
 475         struct solaris_x86_slice
 476                 v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
 477         unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
 478         char    v_asciilabel[128];      /* for compatibility */
 479 };
 480
 481 #endif /* CONFIG_SOLARIS_X86_PARTITION */
 482
 483 #ifdef CONFIG_BSD_DISKLABEL
 484 /*
 485  * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
 486  * updated by Marc Espie <Marc.Espie@openbsd.org>
 487  */
 488
 489 /* check against BSD src/sys/sys/disklabel.h for consistency */
 490
 491 #define BSD_DISKMAGIC   (0x82564557UL)  /* The disk magic number */
 492 #define BSD_MAXPARTITIONS       16
 493 #define OPENBSD_MAXPARTITIONS   16
 494 #define BSD_FS_UNUSED           0       /* disklabel unused partition entry ID */
 495 struct bsd_disklabel {
 496         __le32  d_magic;                /* the magic number */
 497         __s16   d_type;                 /* drive type */
 498         __s16   d_subtype;              /* controller/d_type specific */
 499         char    d_typename[16];         /* type name, e.g. "eagle" */
 500         char    d_packname[16];                 /* pack identifier */
 501         __u32   d_secsize;              /* # of bytes per sector */
 502         __u32   d_nsectors;             /* # of data sectors per track */
 503         __u32   d_ntracks;              /* # of tracks per cylinder */
 504         __u32   d_ncylinders;           /* # of data cylinders per unit */
 505         __u32   d_secpercyl;            /* # of data sectors per cylinder */
 506         __u32   d_secperunit;           /* # of data sectors per unit */
 507         __u16   d_sparespertrack;       /* # of spare sectors per track */
 508         __u16   d_sparespercyl;         /* # of spare sectors per cylinder */
 509         __u32   d_acylinders;           /* # of alt. cylinders per unit */
 510         __u16   d_rpm;                  /* rotational speed */
 511         __u16   d_interleave;           /* hardware sector interleave */
 512         __u16   d_trackskew;            /* sector 0 skew, per track */
 513         __u16   d_cylskew;              /* sector 0 skew, per cylinder */
 514         __u32   d_headswitch;           /* head switch time, usec */
 515         __u32   d_trkseek;              /* track-to-track seek, usec */
 516         __u32   d_flags;                /* generic flags */
 517 #define NDDATA 5
 518         __u32   d_drivedata[NDDATA];    /* drive-type specific information */
 519 #define NSPARE 5
 520         __u32   d_spare[NSPARE];        /* reserved for future use */
 521         __le32  d_magic2;               /* the magic number (again) */
 522         __le16  d_checksum;             /* xor of data incl. partitions */
 523
 524                         /* filesystem and partition information: */
 525         __le16  d_npartitions;          /* number of partitions in following */
 526         __le32  d_bbsize;               /* size of boot area at sn0, bytes */
 527         __le32  d_sbsize;               /* max size of fs superblock, bytes */
 528         struct  bsd_partition {         /* the partition table */
 529                 __le32  p_size;         /* number of sectors in partition */
 530                 __le32  p_offset;       /* starting sector */
 531                 __le32  p_fsize;        /* filesystem basic fragment size */
 532                 __u8    p_fstype;       /* filesystem type, see below */
 533                 __u8    p_frag;         /* filesystem fragments per block */
 534                 __le16  p_cpg;          /* filesystem cylinders per group */
 535         } d_partitions[BSD_MAXPARTITIONS];      /* actually may be more */
 536 };
 537
 538 #endif  /* CONFIG_BSD_DISKLABEL */
 539
 540 #ifdef CONFIG_UNIXWARE_DISKLABEL
 541 /*
 542  * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
 543  * and Krzysztof G. Baranowski <kgb@knm.org.pl>
 544  */
 545
 546 #define UNIXWARE_DISKMAGIC     (0xCA5E600DUL)   /* The disk magic number */
 547 #define UNIXWARE_DISKMAGIC2    (0x600DDEEEUL)   /* The slice table magic nr */
 548 #define UNIXWARE_NUMSLICE      16
 549 #define UNIXWARE_FS_UNUSED     0                /* Unused slice entry ID */
 550
 551 struct unixware_slice {
 552         __le16   s_label;       /* label */
 553         __le16   s_flags;       /* permission flags */
 554         __le32   start_sect;    /* starting sector */
 555         __le32   nr_sects;      /* number of sectors in slice */
 556 };
 557
 558 struct unixware_disklabel {
 559         __le32   d_type;                /* drive type */
 560         __le32   d_magic;                /* the magic number */
 561         __le32   d_version;              /* version number */
 562         char    d_serial[12];           /* serial number of the device */
 563         __le32   d_ncylinders;           /* # of data cylinders per device */
 564         __le32   d_ntracks;              /* # of tracks per cylinder */
 565         __le32   d_nsectors;             /* # of data sectors per track */
 566         __le32   d_secsize;              /* # of bytes per sector */
 567         __le32   d_part_start;           /* # of first sector of this partition */
 568         __le32   d_unknown1[12];         /* ? */
 569         __le32  d_alt_tbl;              /* byte offset of alternate table */
 570         __le32  d_alt_len;              /* byte length of alternate table */
 571         __le32  d_phys_cyl;             /* # of physical cylinders per device */
 572         __le32  d_phys_trk;             /* # of physical tracks per cylinder */
 573         __le32  d_phys_sec;             /* # of physical sectors per track */
 574         __le32  d_phys_bytes;           /* # of physical bytes per sector */
 575         __le32  d_unknown2;             /* ? */
 576         __le32   d_unknown3;             /* ? */
 577         __le32  d_pad[8];               /* pad */
 578
 579         struct unixware_vtoc {
 580                 __le32  v_magic;                /* the magic number */
 581                 __le32  v_version;              /* version number */
 582                 char    v_name[8];              /* volume name */
 583                 __le16  v_nslices;              /* # of slices */
 584                 __le16  v_unknown1;             /* ? */
 585                 __le32  v_reserved[10];         /* reserved */
 586                 struct unixware_slice
 587                         v_slice[UNIXWARE_NUMSLICE];     /* slice headers */
 588         } vtoc;
 589
 590 };  /* 408 */
 591
 592 #endif /* CONFIG_UNIXWARE_DISKLABEL */
 593
 594 #ifdef CONFIG_MINIX_SUBPARTITION
 595 #   define MINIX_NR_SUBPARTITIONS  4
 596 #endif /* CONFIG_MINIX_SUBPARTITION */
 597
 598 #define ADDPART_FLAG_NONE       0
 599 #define ADDPART_FLAG_RAID       1
 600 #define ADDPART_FLAG_WHOLEDISK  2
 601
 602 extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
 603 extern void blk_free_devt(dev_t devt);
 604 extern dev_t blk_lookup_devt(const char *name, int partno);
 605 extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 606
 607 extern int disk_expand_part_tbl(struct gendisk *disk, int target);
 608 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
 609 extern int invalidate_partitions(struct gendisk *disk, struct block_device *bdev);
 610 extern struct hd_struct * __must_check add_partition(struct gendisk *disk,
 611                                                      int partno, sector_t start,
 612                                                      sector_t len, int flags,
 613                                                      struct partition_meta_info
 614                                                        *info);
 615 extern void __delete_partition(struct percpu_ref *);
 616 extern void delete_partition(struct gendisk *, int);
 617 extern void printk_all_partitions(void);
 618
 619 extern struct gendisk *alloc_disk_node(int minors, int node_id);
 620 extern struct gendisk *alloc_disk(int minors);
 621 extern struct kobject *get_disk(struct gendisk *disk);
 622 extern void put_disk(struct gendisk *disk);
 623 extern void blk_register_region(dev_t devt, unsigned long range,
 624                         struct module *module,
 625                         struct kobject *(*probe)(dev_t, int *, void *),
 626                         int (*lock)(dev_t, void *),
 627                         void *data);
 628 extern void blk_unregister_region(dev_t devt, unsigned long range);
 629
 630 extern ssize_t part_size_show(struct device *dev,
 631                               struct device_attribute *attr, char *buf);
 632 extern ssize_t part_stat_show(struct device *dev,
 633                               struct device_attribute *attr, char *buf);
 634 extern ssize_t part_inflight_show(struct device *dev,
 635                               struct device_attribute *attr, char *buf);
 636 #ifdef CONFIG_FAIL_MAKE_REQUEST
 637 extern ssize_t part_fail_show(struct device *dev,
 638                               struct device_attribute *attr, char *buf);
 639 extern ssize_t part_fail_store(struct device *dev,
 640                                struct device_attribute *attr,
 641                                const char *buf, size_t count);
 642 #endif /* CONFIG_FAIL_MAKE_REQUEST */
 643
 644 static inline int hd_ref_init(struct hd_struct *part)
 645 {
 646         if (percpu_ref_init(&part->ref, __delete_partition, 0,
 647                                 GFP_KERNEL))
 648                 return -ENOMEM;
 649         return 0;
 650 }
 651
 652 static inline void hd_struct_get(struct hd_struct *part)
 653 {
 654         percpu_ref_get(&part->ref);
 655 }
 656
 657 static inline int hd_struct_try_get(struct hd_struct *part)
 658 {
 659         return percpu_ref_tryget_live(&part->ref);
 660 }
 661
 662 static inline void hd_struct_put(struct hd_struct *part)
 663 {
 664         percpu_ref_put(&part->ref);
 665 }
 666
 667 static inline void hd_struct_kill(struct hd_struct *part)
 668 {
 669         percpu_ref_kill(&part->ref);
 670 }
 671
 672 static inline void hd_free_part(struct hd_struct *part)
 673 {
 674         free_part_stats(part);
 675         free_part_info(part);
 676         percpu_ref_exit(&part->ref);
 677 }
 678
 679 /*
 680  * Any access of part->nr_sects which is not protected by partition
 681  * bd_mutex or gendisk bdev bd_mutex, should be done using this
 682  * accessor function.
 683  *
 684  * Code written along the lines of i_size_read() and i_size_write().
 685  * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption
 686  * on.
 687  */
 688 static inline sector_t part_nr_sects_read(struct hd_struct *part)
 689 {
 690 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
 691         sector_t nr_sects;
 692         unsigned seq;
 693         do {
 694                 seq = read_seqcount_begin(&part->nr_sects_seq);
 695                 nr_sects = part->nr_sects;
 696         } while (read_seqcount_retry(&part->nr_sects_seq, seq));
 697         return nr_sects;
 698 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
 699         sector_t nr_sects;
 700
 701         preempt_disable();
 702         nr_sects = part->nr_sects;
 703         preempt_enable();
 704         return nr_sects;
 705 #else
 706         return part->nr_sects;
 707 #endif
 708 }
 709
 710 /*
 711  * Should be called with mutex lock held (typically bd_mutex) of partition
 712  * to provide mutual exlusion among writers otherwise seqcount might be
 713  * left in wrong state leaving the readers spinning infinitely.
 714  */
 715 static inline void part_nr_sects_write(struct hd_struct *part, sector_t size)
 716 {
 717 #if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP)
 718         write_seqcount_begin(&part->nr_sects_seq);
 719         part->nr_sects = size;
 720         write_seqcount_end(&part->nr_sects_seq);
 721 #elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT)
 722         preempt_disable();
 723         part->nr_sects = size;
 724         preempt_enable();
 725 #else
 726         part->nr_sects = size;
 727 #endif
 728 }
 729
 730 #else /* CONFIG_BLOCK */
 731
 732 static inline void printk_all_partitions(void) { }
 733
 734 static inline dev_t blk_lookup_devt(const char *name, int partno)
 735 {
 736         dev_t devt = MKDEV(0, 0);
 737         return devt;
 738 }
 739
 740 static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
 741 {
 742         return -EINVAL;
 743 }
 744 #endif /* CONFIG_BLOCK */
 745
 746 #endif /* _LINUX_GENHD_H */