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
  16 #ifdef CONFIG_BLOCK
  17
  18 #define kobj_to_dev(k)          container_of((k), struct device, kobj)
  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 extern const struct seq_operations partitions_op;
  29 extern const struct seq_operations diskstats_op;
  30
  31 enum {
  32 /* These three have identical behaviour; use the second one if DOS FDISK gets
  33    confused about extended/logical partitions starting past cylinder 1023. */
  34         DOS_EXTENDED_PARTITION = 5,
  35         LINUX_EXTENDED_PARTITION = 0x85,
  36         WIN98_EXTENDED_PARTITION = 0x0f,
  37
  38         SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,
  39
  40         LINUX_SWAP_PARTITION = 0x82,
  41         LINUX_DATA_PARTITION = 0x83,
  42         LINUX_LVM_PARTITION = 0x8e,
  43         LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
  44
  45         SOLARIS_X86_PARTITION = LINUX_SWAP_PARTITION,
  46         NEW_SOLARIS_X86_PARTITION = 0xbf,
  47
  48         DM6_AUX1PARTITION = 0x51,       /* no DDO:  use xlated geom */
  49         DM6_AUX3PARTITION = 0x53,       /* no DDO:  use xlated geom */
  50         DM6_PARTITION = 0x54,           /* has DDO: use xlated geom & offset */
  51         EZD_PARTITION = 0x55,           /* EZ-DRIVE */
  52
  53         FREEBSD_PARTITION = 0xa5,       /* FreeBSD Partition ID */
  54         OPENBSD_PARTITION = 0xa6,       /* OpenBSD Partition ID */
  55         NETBSD_PARTITION = 0xa9,        /* NetBSD Partition ID */
  56         BSDI_PARTITION = 0xb7,          /* BSDI Partition ID */
  57         MINIX_PARTITION = 0x81,         /* Minix Partition ID */
  58         UNIXWARE_PARTITION = 0x63,      /* Same as GNU_HURD and SCO Unix */
  59 };
  60
  61 #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 struct hd_struct {
  91         sector_t start_sect;
  92         sector_t nr_sects;
  93         struct device __dev;
  94         struct kobject *holder_dir;
  95         int policy, partno;
  96 #ifdef CONFIG_FAIL_MAKE_REQUEST
  97         int make_it_fail;
  98 #endif
  99         unsigned long stamp;
 100         int in_flight;
 101 #ifdef  CONFIG_SMP
 102         struct disk_stats *dkstats;
 103 #else
 104         struct disk_stats dkstats;
 105 #endif
 106         struct rcu_head rcu_head;
 107 };
 108
 109 #define GENHD_FL_REMOVABLE                      1
 110 #define GENHD_FL_DRIVERFS                       2
 111 #define GENHD_FL_MEDIA_CHANGE_NOTIFY            4
 112 #define GENHD_FL_CD                             8
 113 #define GENHD_FL_UP                             16
 114 #define GENHD_FL_SUPPRESS_PARTITION_INFO        32
 115 #define GENHD_FL_FAIL                           64
 116
 117 struct gendisk {
 118         /* major, first_minor, minors and ext_minors are input
 119          * parameters only, don't use directly.  Use disk_devt() and
 120          * disk_max_parts().
 121          */
 122         int major;                      /* major number of driver */
 123         int first_minor;
 124         int minors;                     /* maximum number of minors, =1 for
 125                                          * disks that can't be partitioned. */
 126         int ext_minors;                 /* number of extended dynamic minors */
 127
 128         char disk_name[32];             /* name of major driver */
 129
 130         /* Array of pointers to partitions indexed by partno.
 131          * Protected with matching bdev lock but stat and other
 132          * non-critical accesses use RCU.  Always access through
 133          * helpers.
 134          */
 135         struct hd_struct **__part;
 136         struct hd_struct part0;
 137
 138         struct block_device_operations *fops;
 139         struct request_queue *queue;
 140         void *private_data;
 141
 142         int flags;
 143         struct device *driverfs_dev;  // FIXME: remove
 144         struct kobject *holder_dir;
 145         struct kobject *slave_dir;
 146
 147         struct timer_rand_state *random;
 148         int policy;
 149
 150         atomic_t sync_io;               /* RAID */
 151         unsigned long stamp;
 152         int in_flight;
 153 #ifdef  CONFIG_SMP
 154         struct disk_stats *dkstats;
 155 #else
 156         struct disk_stats dkstats;
 157 #endif
 158         struct work_struct async_notify;
 159 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 160         struct blk_integrity *integrity;
 161 #endif
 162 };
 163
 164 static inline struct gendisk *part_to_disk(struct hd_struct *part)
 165 {
 166         if (likely(part)) {
 167                 if (part->partno)
 168                         return dev_to_disk(part_to_dev(part)->parent);
 169                 else
 170                         return dev_to_disk(part_to_dev(part));
 171         }
 172         return NULL;
 173 }
 174
 175 static inline int disk_max_parts(struct gendisk *disk)
 176 {
 177         return disk->minors + disk->ext_minors;
 178 }
 179
 180 static inline bool disk_partitionable(struct gendisk *disk)
 181 {
 182         return disk_max_parts(disk) > 1;
 183 }
 184
 185 static inline dev_t disk_devt(struct gendisk *disk)
 186 {
 187         return disk_to_dev(disk)->devt;
 188 }
 189
 190 static inline dev_t part_devt(struct hd_struct *part)
 191 {
 192         return part_to_dev(part)->devt;
 193 }
 194
 195 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 196
 197 static inline void disk_put_part(struct hd_struct *part)
 198 {
 199         if (likely(part))
 200                 put_device(part_to_dev(part));
 201 }
 202
 203 /*
 204  * Smarter partition iterator without context limits.
 205  */
 206 #define DISK_PITER_REVERSE      (1 << 0) /* iterate in the reverse direction */
 207 #define DISK_PITER_INCL_EMPTY   (1 << 1) /* include 0-sized parts */
 208 #define DISK_PITER_INCL_PART0   (1 << 2) /* include partition 0 */
 209
 210 struct disk_part_iter {
 211         struct gendisk          *disk;
 212         struct hd_struct        *part;
 213         int                     idx;
 214         unsigned int            flags;
 215 };
 216
 217 extern void disk_part_iter_init(struct disk_part_iter *piter,
 218                                  struct gendisk *disk, unsigned int flags);
 219 extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
 220 extern void disk_part_iter_exit(struct disk_part_iter *piter);
 221
 222 extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
 223                                              sector_t sector);
 224
 225 /*
 226  * Macros to operate on percpu disk statistics:
 227  *
 228  * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 229  * and should be called between disk_stat_lock() and
 230  * disk_stat_unlock().
 231  *
 232  * part_stat_read() can be called at any time.
 233  *
 234  * part_stat_{add|set_all}() and {init|free}_part_stats are for
 235  * internal use only.
 236  */
 237 #ifdef  CONFIG_SMP
 238 #define disk_stat_lock()        ({ rcu_read_lock(); get_cpu(); })
 239 #define disk_stat_unlock()      do { put_cpu(); rcu_read_unlock(); } while (0)
 240
 241 #define disk_stat_add(cpu, gendiskp, field, addnd)                      \
 242         (per_cpu_ptr(gendiskp->dkstats, cpu)->field += addnd)
 243
 244 #define disk_stat_read(gendiskp, field)                                 \
 245 ({                                                                      \
 246         typeof(gendiskp->dkstats->field) res = 0;                       \
 247         int i;                                                          \
 248         for_each_possible_cpu(i)                                        \
 249                 res += per_cpu_ptr(gendiskp->dkstats, i)->field;        \
 250         res;                                                            \
 251 })
 252
 253 static inline void disk_stat_set_all(struct gendisk *gendiskp, int value)
 254 {
 255         int i;
 256
 257         for_each_possible_cpu(i)
 258                 memset(per_cpu_ptr(gendiskp->dkstats, i), value,
 259                                 sizeof(struct disk_stats));
 260 }
 261
 262 #define part_stat_add(cpu, part, field, addnd)                          \
 263         (per_cpu_ptr(part->dkstats, cpu)->field += addnd)
 264
 265 #define all_stat_add(cpu, gendiskp, part, field, addnd, sector)         \
 266 ({                                                                      \
 267         if (part)                                                       \
 268                 part_stat_add(cpu, part, field, addnd);                 \
 269         disk_stat_add(cpu, gendiskp, field, addnd);                     \
 270 })
 271
 272 #define part_stat_read(part, field)                                     \
 273 ({                                                                      \
 274         typeof(part->dkstats->field) res = 0;                           \
 275         int i;                                                          \
 276         for_each_possible_cpu(i)                                        \
 277                 res += per_cpu_ptr(part->dkstats, i)->field;            \
 278         res;                                                            \
 279 })
 280
 281 static inline void part_stat_set_all(struct hd_struct *part, int value)
 282 {
 283         int i;
 284
 285         for_each_possible_cpu(i)
 286                 memset(per_cpu_ptr(part->dkstats, i), value,
 287                                 sizeof(struct disk_stats));
 288 }
 289
 290 #else /* !CONFIG_SMP */
 291 #define disk_stat_lock()        ({ rcu_read_lock(); 0; })
 292 #define disk_stat_unlock()      rcu_read_unlock()
 293
 294 #define disk_stat_add(cpu, gendiskp, field, addnd)                      \
 295         (gendiskp->dkstats.field += addnd)
 296 #define disk_stat_read(gendiskp, field) (gendiskp->dkstats.field)
 297
 298 static inline void disk_stat_set_all(struct gendisk *gendiskp, int value)
 299 {
 300         memset(&gendiskp->dkstats, value, sizeof (struct disk_stats));
 301 }
 302
 303 #define part_stat_add(cpu, part, field, addnd)                          \
 304         (part->dkstats.field += addnd)
 305
 306 #define all_stat_add(cpu, gendiskp, part, field, addnd, sector)         \
 307 ({                                                                      \
 308         if (part)                                                       \
 309                 part_stat_add(cpu, part, field, addnd);                 \
 310         disk_stat_add(cpu, gendiskp, field, addnd);                     \
 311 })
 312
 313 #define part_stat_read(part, field)     (part->dkstats.field)
 314
 315 static inline void part_stat_set_all(struct hd_struct *part, int value)
 316 {
 317         memset(&part->dkstats, value, sizeof(struct disk_stats));
 318 }
 319
 320 #endif /* CONFIG_SMP */
 321
 322 #define disk_stat_dec(cpu, gendiskp, field)                             \
 323         disk_stat_add(cpu, gendiskp, field, -1)
 324 #define disk_stat_inc(cpu, gendiskp, field)                             \
 325         disk_stat_add(cpu, gendiskp, field, 1)
 326 #define disk_stat_sub(cpu, gendiskp, field, subnd)                      \
 327         disk_stat_add(cpu, gendiskp, field, -subnd)
 328
 329 #define part_stat_dec(cpu, gendiskp, field)                             \
 330         part_stat_add(cpu, gendiskp, field, -1)
 331 #define part_stat_inc(cpu, gendiskp, field)                             \
 332         part_stat_add(cpu, gendiskp, field, 1)
 333 #define part_stat_sub(cpu, gendiskp, field, subnd)                      \
 334         part_stat_add(cpu, gendiskp, field, -subnd)
 335
 336 #define all_stat_dec(cpu, gendiskp, field, sector)                      \
 337         all_stat_add(cpu, gendiskp, field, -1, sector)
 338 #define all_stat_inc(cpu, gendiskp, part, field, sector)                \
 339         all_stat_add(cpu, gendiskp, part, field, 1, sector)
 340 #define all_stat_sub(cpu, gendiskp, part, field, subnd, sector)         \
 341         all_stat_add(cpu, gendiskp, part, field, -subnd, sector)
 342
 343 /* Inlines to alloc and free disk stats in struct gendisk */
 344 #ifdef  CONFIG_SMP
 345 static inline int init_disk_stats(struct gendisk *disk)
 346 {
 347         disk->dkstats = alloc_percpu(struct disk_stats);
 348         if (!disk->dkstats)
 349                 return 0;
 350         return 1;
 351 }
 352
 353 static inline void free_disk_stats(struct gendisk *disk)
 354 {
 355         free_percpu(disk->dkstats);
 356 }
 357
 358 static inline int init_part_stats(struct hd_struct *part)
 359 {
 360         part->dkstats = alloc_percpu(struct disk_stats);
 361         if (!part->dkstats)
 362                 return 0;
 363         return 1;
 364 }
 365
 366 static inline void free_part_stats(struct hd_struct *part)
 367 {
 368         free_percpu(part->dkstats);
 369 }
 370
 371 #else   /* CONFIG_SMP */
 372 static inline int init_disk_stats(struct gendisk *disk)
 373 {
 374         return 1;
 375 }
 376
 377 static inline void free_disk_stats(struct gendisk *disk)
 378 {
 379 }
 380
 381 static inline int init_part_stats(struct hd_struct *part)
 382 {
 383         return 1;
 384 }
 385
 386 static inline void free_part_stats(struct hd_struct *part)
 387 {
 388 }
 389 #endif  /* CONFIG_SMP */
 390
 391 /* drivers/block/ll_rw_blk.c */
 392 extern void disk_round_stats(int cpu, struct gendisk *disk);
 393 extern void part_round_stats(int cpu, struct hd_struct *part);
 394
 395 /* drivers/block/genhd.c */
 396 extern int get_blkdev_list(char *, int);
 397 extern void add_disk(struct gendisk *disk);
 398 extern void del_gendisk(struct gendisk *gp);
 399 extern void unlink_gendisk(struct gendisk *gp);
 400 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 401 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 402
 403 extern void set_device_ro(struct block_device *bdev, int flag);
 404 extern void set_disk_ro(struct gendisk *disk, int flag);
 405
 406 /* drivers/char/random.c */
 407 extern void add_disk_randomness(struct gendisk *disk);
 408 extern void rand_initialize_disk(struct gendisk *disk);
 409
 410 static inline sector_t get_start_sect(struct block_device *bdev)
 411 {
 412         return bdev->bd_contains == bdev ? 0 : bdev->bd_part->start_sect;
 413 }
 414 static inline sector_t get_capacity(struct gendisk *disk)
 415 {
 416         return disk->part0.nr_sects;
 417 }
 418 static inline void set_capacity(struct gendisk *disk, sector_t size)
 419 {
 420         disk->part0.nr_sects = size;
 421 }
 422
 423 #ifdef CONFIG_SOLARIS_X86_PARTITION
 424
 425 #define SOLARIS_X86_NUMSLICE    16
 426 #define SOLARIS_X86_VTOC_SANE   (0x600DDEEEUL)
 427
 428 struct solaris_x86_slice {
 429         __le16 s_tag;           /* ID tag of partition */
 430         __le16 s_flag;          /* permission flags */
 431         __le32 s_start;         /* start sector no of partition */
 432         __le32 s_size;          /* # of blocks in partition */
 433 };
 434
 435 struct solaris_x86_vtoc {
 436         unsigned int v_bootinfo[3];     /* info needed by mboot (unsupported) */
 437         __le32 v_sanity;                /* to verify vtoc sanity */
 438         __le32 v_version;               /* layout version */
 439         char    v_volume[8];            /* volume name */
 440         __le16  v_sectorsz;             /* sector size in bytes */
 441         __le16  v_nparts;               /* number of partitions */
 442         unsigned int v_reserved[10];    /* free space */
 443         struct solaris_x86_slice
 444                 v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
 445         unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
 446         char    v_asciilabel[128];      /* for compatibility */
 447 };
 448
 449 #endif /* CONFIG_SOLARIS_X86_PARTITION */
 450
 451 #ifdef CONFIG_BSD_DISKLABEL
 452 /*
 453  * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
 454  * updated by Marc Espie <Marc.Espie@openbsd.org>
 455  */
 456
 457 /* check against BSD src/sys/sys/disklabel.h for consistency */
 458
 459 #define BSD_DISKMAGIC   (0x82564557UL)  /* The disk magic number */
 460 #define BSD_MAXPARTITIONS       16
 461 #define OPENBSD_MAXPARTITIONS   16
 462 #define BSD_FS_UNUSED           0       /* disklabel unused partition entry ID */
 463 struct bsd_disklabel {
 464         __le32  d_magic;                /* the magic number */
 465         __s16   d_type;                 /* drive type */
 466         __s16   d_subtype;              /* controller/d_type specific */
 467         char    d_typename[16];         /* type name, e.g. "eagle" */
 468         char    d_packname[16];                 /* pack identifier */
 469         __u32   d_secsize;              /* # of bytes per sector */
 470         __u32   d_nsectors;             /* # of data sectors per track */
 471         __u32   d_ntracks;              /* # of tracks per cylinder */
 472         __u32   d_ncylinders;           /* # of data cylinders per unit */
 473         __u32   d_secpercyl;            /* # of data sectors per cylinder */
 474         __u32   d_secperunit;           /* # of data sectors per unit */
 475         __u16   d_sparespertrack;       /* # of spare sectors per track */
 476         __u16   d_sparespercyl;         /* # of spare sectors per cylinder */
 477         __u32   d_acylinders;           /* # of alt. cylinders per unit */
 478         __u16   d_rpm;                  /* rotational speed */
 479         __u16   d_interleave;           /* hardware sector interleave */
 480         __u16   d_trackskew;            /* sector 0 skew, per track */
 481         __u16   d_cylskew;              /* sector 0 skew, per cylinder */
 482         __u32   d_headswitch;           /* head switch time, usec */
 483         __u32   d_trkseek;              /* track-to-track seek, usec */
 484         __u32   d_flags;                /* generic flags */
 485 #define NDDATA 5
 486         __u32   d_drivedata[NDDATA];    /* drive-type specific information */
 487 #define NSPARE 5
 488         __u32   d_spare[NSPARE];        /* reserved for future use */
 489         __le32  d_magic2;               /* the magic number (again) */
 490         __le16  d_checksum;             /* xor of data incl. partitions */
 491
 492                         /* filesystem and partition information: */
 493         __le16  d_npartitions;          /* number of partitions in following */
 494         __le32  d_bbsize;               /* size of boot area at sn0, bytes */
 495         __le32  d_sbsize;               /* max size of fs superblock, bytes */
 496         struct  bsd_partition {         /* the partition table */
 497                 __le32  p_size;         /* number of sectors in partition */
 498                 __le32  p_offset;       /* starting sector */
 499                 __le32  p_fsize;        /* filesystem basic fragment size */
 500                 __u8    p_fstype;       /* filesystem type, see below */
 501                 __u8    p_frag;         /* filesystem fragments per block */
 502                 __le16  p_cpg;          /* filesystem cylinders per group */
 503         } d_partitions[BSD_MAXPARTITIONS];      /* actually may be more */
 504 };
 505
 506 #endif  /* CONFIG_BSD_DISKLABEL */
 507
 508 #ifdef CONFIG_UNIXWARE_DISKLABEL
 509 /*
 510  * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
 511  * and Krzysztof G. Baranowski <kgb@knm.org.pl>
 512  */
 513
 514 #define UNIXWARE_DISKMAGIC     (0xCA5E600DUL)   /* The disk magic number */
 515 #define UNIXWARE_DISKMAGIC2    (0x600DDEEEUL)   /* The slice table magic nr */
 516 #define UNIXWARE_NUMSLICE      16
 517 #define UNIXWARE_FS_UNUSED     0                /* Unused slice entry ID */
 518
 519 struct unixware_slice {
 520         __le16   s_label;       /* label */
 521         __le16   s_flags;       /* permission flags */
 522         __le32   start_sect;    /* starting sector */
 523         __le32   nr_sects;      /* number of sectors in slice */
 524 };
 525
 526 struct unixware_disklabel {
 527         __le32   d_type;                /* drive type */
 528         __le32   d_magic;                /* the magic number */
 529         __le32   d_version;              /* version number */
 530         char    d_serial[12];           /* serial number of the device */
 531         __le32   d_ncylinders;           /* # of data cylinders per device */
 532         __le32   d_ntracks;              /* # of tracks per cylinder */
 533         __le32   d_nsectors;             /* # of data sectors per track */
 534         __le32   d_secsize;              /* # of bytes per sector */
 535         __le32   d_part_start;           /* # of first sector of this partition */
 536         __le32   d_unknown1[12];         /* ? */
 537         __le32  d_alt_tbl;              /* byte offset of alternate table */
 538         __le32  d_alt_len;              /* byte length of alternate table */
 539         __le32  d_phys_cyl;             /* # of physical cylinders per device */
 540         __le32  d_phys_trk;             /* # of physical tracks per cylinder */
 541         __le32  d_phys_sec;             /* # of physical sectors per track */
 542         __le32  d_phys_bytes;           /* # of physical bytes per sector */
 543         __le32  d_unknown2;             /* ? */
 544         __le32   d_unknown3;             /* ? */
 545         __le32  d_pad[8];               /* pad */
 546
 547         struct unixware_vtoc {
 548                 __le32  v_magic;                /* the magic number */
 549                 __le32  v_version;              /* version number */
 550                 char    v_name[8];              /* volume name */
 551                 __le16  v_nslices;              /* # of slices */
 552                 __le16  v_unknown1;             /* ? */
 553                 __le32  v_reserved[10];         /* reserved */
 554                 struct unixware_slice
 555                         v_slice[UNIXWARE_NUMSLICE];     /* slice headers */
 556         } vtoc;
 557
 558 };  /* 408 */
 559
 560 #endif /* CONFIG_UNIXWARE_DISKLABEL */
 561
 562 #ifdef CONFIG_MINIX_SUBPARTITION
 563 #   define MINIX_NR_SUBPARTITIONS  4
 564 #endif /* CONFIG_MINIX_SUBPARTITION */
 565
 566 #define ADDPART_FLAG_NONE       0
 567 #define ADDPART_FLAG_RAID       1
 568 #define ADDPART_FLAG_WHOLEDISK  2
 569
 570 extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
 571 extern void blk_free_devt(dev_t devt);
 572 extern dev_t blk_lookup_devt(const char *name, int partno);
 573 extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 574
 575 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
 576 extern int __must_check add_partition(struct gendisk *, int, sector_t, sector_t, int);
 577 extern void delete_partition(struct gendisk *, int);
 578 extern void printk_all_partitions(void);
 579
 580 extern struct gendisk *alloc_disk_node(int minors, int node_id);
 581 extern struct gendisk *alloc_disk(int minors);
 582 extern struct gendisk *alloc_disk_ext_node(int minors, int ext_minrs,
 583                                            int node_id);
 584 extern struct gendisk *alloc_disk_ext(int minors, int ext_minors);
 585 extern struct kobject *get_disk(struct gendisk *disk);
 586 extern void put_disk(struct gendisk *disk);
 587 extern void blk_register_region(dev_t devt, unsigned long range,
 588                         struct module *module,
 589                         struct kobject *(*probe)(dev_t, int *, void *),
 590                         int (*lock)(dev_t, void *),
 591                         void *data);
 592 extern void blk_unregister_region(dev_t devt, unsigned long range);
 593
 594 #else /* CONFIG_BLOCK */
 595
 596 static inline void printk_all_partitions(void) { }
 597
 598 static inline dev_t blk_lookup_devt(const char *name, int partno)
 599 {
 600         dev_t devt = MKDEV(0, 0);
 601         return devt;
 602 }
 603
 604 #endif /* CONFIG_BLOCK */
 605
 606 #endif /* _LINUX_GENHD_H */