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