LXR linux/include/linux/genhd.h

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