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 #include <linux/uuid.h>
  18
  19 #ifdef CONFIG_BLOCK
  20
  21 #define dev_to_disk(device)     container_of((device), struct gendisk, part0.__dev)
  22 #define dev_to_part(device)     container_of((device), struct hd_struct, __dev)
  23 #define disk_to_dev(disk)       (&(disk)->part0.__dev)
  24 #define part_to_dev(part)       (&((part)->__dev))
  25
  26 extern struct device_type part_type;
  27 extern struct kobject *block_depr;
  28 extern struct class block_class;
  29
  30 enum {
  31 /* These three have identical behaviour; use the second one if DOS FDISK gets
  32    confused about extended/logical partitions starting past cylinder 1023. */
  33         DOS_EXTENDED_PARTITION = 5,
  34         LINUX_EXTENDED_PARTITION = 0x85,
  35         WIN98_EXTENDED_PARTITION = 0x0f,
  36
  37         SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
  38
  39         LINUX_SWAP_PARTITION = 0x82,
  40         LINUX_DATA_PARTITION = 0x83,
  41         LINUX_LVM_PARTITION = 0x8e,
  42         LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
  43
  44         SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
  45         NEW_SOLARIS_X86_PARTITION = 0xbf,
  46
  47         DM6_AUX1PARTITION = 0x51,       /* no DDO:  use xlated geom */
  48         DM6_AUX3PARTITION = 0x53,       /* no DDO:  use xlated geom */
  49         DM6_PARTITION = 0x54,           /* has DDO: use xlated geom & offset */
  50         EZD_PARTITION = 0x55,           /* EZ-DRIVE */
  51
  52         FREEBSD_PARTITION = 0xa5,       /* FreeBSD Partition ID */
  53         OPENBSD_PARTITION = 0xa6,       /* OpenBSD Partition ID */
  54         NETBSD_PARTITION = 0xa9,        /* NetBSD Partition ID */
  55         BSDI_PARTITION = 0xb7,          /* BSDI Partition ID */
  56         MINIX_PARTITION = 0x81,         /* Minix Partition ID */
  57         UNIXWARE_PARTITION = 0x63,      /* Same as GNU_HURD and SCO Unix */
  58 };
  59
  60 #define DISK_MAX_PARTS                  256
  61 #define DISK_NAME_LEN                   32
  62
  63 #include <linux/major.h>
  64 #include <linux/device.h>
  65 #include <linux/smp.h>
  66 #include <linux/string.h>
  67 #include <linux/fs.h>
  68 #include <linux/workqueue.h>
  69
  70 struct partition {
  71         unsigned char boot_ind;         /* 0x80 - active */
  72         unsigned char head;             /* starting head */
  73         unsigned char sector;           /* starting sector */
  74         unsigned char cyl;              /* starting cylinder */
  75         unsigned char sys_ind;          /* What partition type */
  76         unsigned char end_head;         /* end head */
  77         unsigned char end_sector;       /* end sector */
  78         unsigned char end_cyl;          /* end cylinder */
  79         __le32 start_sect;      /* starting sector counting from 0 */
  80         __le32 nr_sects;                /* nr of sectors in partition */
  81 } __attribute__((packed));
  82
  83 struct disk_stats {
  84         unsigned long sectors[2];       /* READs and WRITEs */
  85         unsigned long ios[2];
  86         unsigned long merges[2];
  87         unsigned long ticks[2];
  88         unsigned long io_ticks;
  89         unsigned long time_in_queue;
  90 };
  91
  92 #define PARTITION_META_INFO_VOLNAMELTH  64
  93 /*
  94  * Enough for the string representation of any kind of UUID plus NULL.
  95  * EFI UUID is 36 characters. MSDOS UUID is 11 characters.
  96  */
  97 #define PARTITION_META_INFO_UUIDLTH     (UUID_STRING_LEN + 1)
  98
  99 struct partition_meta_info {
 100         char uuid[PARTITION_META_INFO_UUIDLTH];
 101         u8 volname[PARTITION_META_INFO_VOLNAMELTH];
 102 };
 103
 104 struct hd_struct {
 105         sector_t start_sect;
 106         /*
 107          * nr_sects is protected by sequence counter. One might extend a
 108          * partition while IO is happening to it and update of nr_sects
 109          * can be non-atomic on 32bit machines with 64bit sector_t.
 110          */
 111         sector_t nr_sects;
 112         seqcount_t nr_sects_seq;
 113         sector_t alignment_offset;
 114         unsigned int discard_alignment;
 115         struct device __dev;
 116         struct kobject *holder_dir;
 117         int policy, partno;
 118         struct partition_meta_info *info;
 119 #ifdef CONFIG_FAIL_MAKE_REQUEST
 120         int make_it_fail;
 121 #endif
 122         unsigned long stamp;
 123         atomic_t in_flight[2];
 124 #ifdef  CONFIG_SMP
 125         struct disk_stats __percpu *dkstats;
 126 #else
 127         struct disk_stats dkstats;
 128 #endif
 129         struct percpu_ref ref;
 130         struct rcu_head rcu_head;
 131 };
 132
 133 #define GENHD_FL_REMOVABLE                      1
 134 /* 2 is unused */
 135 #define GENHD_FL_MEDIA_CHANGE_NOTIFY            4
 136 #define GENHD_FL_CD                             8
 137 #define GENHD_FL_UP                             16
 138 #define GENHD_FL_SUPPRESS_PARTITION_INFO        32
 139 #define GENHD_FL_EXT_DEVT                       64 /* allow extended devt */
 140 #define GENHD_FL_NATIVE_CAPACITY                128
 141 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE     256
 142 #define GENHD_FL_NO_PART_SCAN                   512
 143
 144 enum {
 145         DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
 146         DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
 147 };
 148
 149 struct disk_part_tbl {
 150         struct rcu_head rcu_head;
 151         int len;
 152         struct hd_struct __rcu *last_lookup;
 153         struct hd_struct __rcu *part[];
 154 };
 155
 156 struct disk_events;
 157 struct badblocks;
 158
 159 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 160
 161 struct blk_integrity {
 162         struct blk_integrity_profile    *profile;
 163         unsigned char                   flags;
 164         unsigned char                   tuple_size;
 165         unsigned char                   interval_exp;
 166         unsigned char                   tag_size;
 167 };
 168
 169 #endif  /* CONFIG_BLK_DEV_INTEGRITY */
 170 struct disk_devt {
 171         atomic_t count;
 172         void (*release)(struct disk_devt *disk_devt);
 173 };
 174
 175 void put_disk_devt(struct disk_devt *disk_devt);
 176 void get_disk_devt(struct disk_devt *disk_devt);
 177
 178 struct gendisk {
 179         /* major, first_minor and minors are input parameters only,
 180          * don't use directly.  Use disk_devt() and disk_max_parts().
 181          */
 182         int major;                      /* major number of driver */
 183         int first_minor;
 184         int minors;                     /* maximum number of minors, =1 for
 185                                          * disks that can't be partitioned. */
 186         struct disk_devt *disk_devt;
 187
 188         char disk_name[DISK_NAME_LEN];  /* name of major driver */
 189         char *(*devnode)(struct gendisk *gd, umode_t *mode);
 190
 191         unsigned int events;            /* supported events */
 192         unsigned int async_events;      /* async events, subset of all */
 193
 194         /* Array of pointers to partitions indexed by partno.
 195          * Protected with matching bdev lock but stat and other
 196          * non-critical accesses use RCU.  Always access through
 197          * helpers.
 198          */
 199         struct disk_part_tbl __rcu *part_tbl;
 200         struct hd_struct part0;
 201
 202         const struct block_device_operations *fops;
 203         struct request_queue *queue;
 204         void *private_data;
 205
 206         int flags;
 207         struct kobject *slave_dir;
 208
 209         struct timer_rand_state *random;
 210         atomic_t sync_io;               /* RAID */
 211         struct disk_events *ev;
 212 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 213         struct kobject integrity_kobj;
 214 #endif  /* CONFIG_BLK_DEV_INTEGRITY */
 215         int node_id;
 216         struct badblocks *bb;
 217 };
 218
 219 static inline struct gendisk *part_to_disk(struct hd_struct *part)
 220 {
 221         if (likely(part)) {
 222                 if (part->partno)
 223                         return dev_to_disk(part_to_dev(part)->parent);
 224                 else
 225                         return dev_to_disk(part_to_dev(part));
 226         }
 227         return NULL;
 228 }
 229
 230 static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
 231 {
 232         uuid_be_to_bin(uuid_str, (uuid_be *)to);
 233         return 0;
 234 }
 235
 236 static inline int disk_max_parts(struct gendisk *disk)
 237 {
 238         if (disk->flags & GENHD_FL_EXT_DEVT)
 239                 return DISK_MAX_PARTS;
 240         return disk->minors;
 241 }
 242
 243 static inline bool disk_part_scan_enabled(struct gendisk *disk)
 244 {
 245         return disk_max_parts(disk) > 1 &&
 246                 !(disk->flags & GENHD_FL_NO_PART_SCAN);
 247 }
 248
 249 static inline dev_t disk_devt(struct gendisk *disk)
 250 {
 251         return disk_to_dev(disk)->devt;
 252 }
 253
 254 static inline dev_t part_devt(struct hd_struct *part)
 255 {
 256         return part_to_dev(part)->devt;
 257 }
 258
 259 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 260
 261 static inline void disk_put_part(struct hd_struct *part)
 262 {
 263         if (likely(part))
 264                 put_device(part_to_dev(part));
 265 }
 266
 267 /*
 268  * Smarter partition iterator without context limits.
 269  */
 270 #define DISK_PITER_REVERSE      (1 << 0) /* iterate in the reverse direction */
 271 #define DISK_PITER_INCL_EMPTY   (1 << 1) /* include 0-sized parts */
 272 #define DISK_PITER_INCL_PART0   (1 << 2) /* include partition 0 */
 273 #define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */
 274
 275 struct disk_part_iter {
 276         struct gendisk          *disk;
 277         struct hd_struct        *part;
 278         int                     idx;
 279         unsigned int            flags;
 280 };
 281
 282 extern void disk_part_iter_init(struct disk_part_iter *piter,
 283                                  struct gendisk *disk, unsigned int flags);
 284 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 285 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 286
 287 extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 288                                              sector_t sector);
 289
 290 /*
 291  * Macros to operate on percpu disk statistics:
 292  *
 293  * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 294  * and should be called between disk_stat_lock() and
 295  * disk_stat_unlock().
 296  *
 297  * part_stat_read() can be called at any time.
 298  *
 299  * part_stat_{add|set_all}() and {init|free}_part_stats are for
 300  * internal use only.
 301  */
 302 #ifdef  CONFIG_SMP
 303 #define part_stat_lock()        ({ rcu_read_lock(); get_cpu(); })
 304 #define part_stat_unlock()      do { put_cpu(); rcu_read_unlock(); } while (0)
 305
 306 #define __part_stat_add(cpu, part, field, addnd)                        \
 307         (per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
 308
 309 #define part_stat_read(part, field)                                     \
 310 ({                                                                      \
 311         typeof((part)->dkstats->field) res = 0;                         \
 312         unsigned int _cpu;                                              \
 313         for_each_possible_cpu(_cpu)                                     \
 314                 res += per_cpu_ptr((part)->dkstats, _cpu)->field;       \
 315         res;                                                            \
 316 })
 317
 318 static inline void part_stat_set_all(struct hd_struct *part, int value)
 319 {
 320         int i;
 321
 322         for_each_possible_cpu(i)
 323                 memset(per_cpu_ptr(part->dkstats, i), value,
 324                                 sizeof(struct disk_stats));
 325 }
 326
 327 static inline int init_part_stats(struct hd_struct *part)
 328 {
 329         part->dkstats = alloc_percpu(struct disk_stats);
 330         if (!part->dkstats)
 331                 return 0;
 332         return 1;
 333 }
 334
 335 static inline void free_part_stats(struct hd_struct *part)
 336 {
 337         free_percpu(part->dkstats);
 338 }
 339
 340 #else /* !CONFIG_SMP */
 341 #define part_stat_lock()        ({ rcu_read_lock(); 0; })
 342 #define part_stat_unlock()      rcu_read_unlock()
 343
 344 #define __part_stat_add(cpu, part, field, addnd)                                \
 345         ((part)->dkstats.field += addnd)
 346
 347 #define part_stat_read(part, field)     ((part)->dkstats.field)
 348
 349 static inline void part_stat_set_all(struct hd_struct *part, int value)
 350 {
 351         memset(&part->dkstats, value, sizeof(struct disk_stats));
 352 }
 353
 354 static inline int init_part_stats(struct hd_struct *part)
 355 {
 356         return 1;
 357 }
 358
 359 static inline void free_part_stats(struct hd_struct *part)
 360 {
 361 }
 362
 363 #endif /* CONFIG_SMP */
 364
 365 #define part_stat_add(cpu, part, field, addnd)  do {                    \
 366         __part_stat_add((cpu), (part), field, addnd);                   \
 367         if ((part)->partno)                                             \
 368                 __part_stat_add((cpu), &part_to_disk((part))->part0,    \
 369                                 field, addnd);                          \
 370 } while (0)
 371
 372 #define part_stat_dec(cpu, gendiskp, field)                             \
 373         part_stat_add(cpu, gendiskp, field, -1)
 374 #define part_stat_inc(cpu, gendiskp, field)                             \
 375         part_stat_add(cpu, gendiskp, field, 1)
 376 #define part_stat_sub(cpu, gendiskp, field, subnd)                      \
 377         part_stat_add(cpu, gendiskp, field, -subnd)
 378
 379 static inline void part_inc_in_flight(struct hd_struct *part, int rw)
 380 {
 381         atomic_inc(&part->in_flight[rw]);
 382         if (part->partno)
 383                 atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
 384 }
 385
 386 static inline void part_dec_in_flight(struct hd_struct *part, int rw)
 387 {
 388         atomic_dec(&part->in_flight[rw]);
 389         if (part->partno)
 390                 atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
 391 }
 392
 393 static inline int part_in_flight(struct hd_struct *part)
 394 {
 395         return atomic_read(&part->in_flight[0]) + atomic_read(&part->in_flight[1]);
 396 }
 397
 398 static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
 399 {
 400         if (disk)
 401                 return kzalloc_node(sizeof(struct partition_meta_info),
 402                                     GFP_KERNEL, disk->node_id);
 403         return kzalloc(sizeof(struct partition_meta_info), GFP_KERNEL);
 404 }
 405
 406 static inline void free_part_info(struct hd_struct *part)
 407 {
 408         kfree(part->info);
 409 }
 410
 411 /* block/blk-core.c */
 412 extern void part_round_stats(int cpu, struct hd_struct *part);
 413
 414 /* block/genhd.c */
 415 extern void device_add_disk(struct device *parent, struct gendisk *disk);
 416 static inline void add_disk(struct gendisk *disk)
 417 {
 418         device_add_disk(NULL, disk);
 419 }
 420
 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) __latent_entropy;
 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 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 731 extern void blk_integrity_add(struct gendisk *);
 732 extern void blk_integrity_del(struct gendisk *);
 733 extern void blk_integrity_revalidate(struct gendisk *);
 734 #else   /* CONFIG_BLK_DEV_INTEGRITY */
 735 static inline void blk_integrity_add(struct gendisk *disk) { }
 736 static inline void blk_integrity_del(struct gendisk *disk) { }
 737 static inline void blk_integrity_revalidate(struct gendisk *disk) { }
 738 #endif  /* CONFIG_BLK_DEV_INTEGRITY */
 739
 740 #else /* CONFIG_BLOCK */
 741
 742 static inline void printk_all_partitions(void) { }
 743
 744 static inline dev_t blk_lookup_devt(const char *name, int partno)
 745 {
 746         dev_t devt = MKDEV(0, 0);
 747         return devt;
 748 }
 749
 750 static inline int blk_part_pack_uuid(const u8 *uuid_str, u8 *to)
 751 {
 752         return -EINVAL;
 753 }
 754 #endif /* CONFIG_BLOCK */
 755
 756 #endif /* _LINUX_GENHD_H */