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