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LIBDISK(3) BSD Library Functions Manual LIBDISK(3)

NAME

Open_Disk, Free_Disk, Debug_Disk, Set_Bios_Geom, Delete_Chunk, Collapse_Disk, Collapse_Chunk, Create_Chunk, All_FreeBSD, CheckRules, Disk_Names, Set_Boot_Mgr, Set_Boot_Blocks, Write_Disk, Cyl_Aligned, Next_Cyl_Aligned, Prev_Cyl_Aligned, Track_Aligned, Next_Track_Aligned, Prev_Track_Aligned, Create_Chunk_DWIM, MakeDev, MakeDevDisk, ShowChunkFlags, chunk_name, slice_type_name — library interface to slice and partition labels

LIBRARY

Interface to Slice and Partition Labels Library (libdisk, −ldisk)

SYNOPSIS

#include <sys/types.h>
#include <libdisk.h>

struct disk *

Open_Disk(const char *devname);

void

Free_Disk(struct disk *disk);

void

Debug_Disk(struct disk *disk);

void

Set_Bios_Geom(struct disk *disk, u_long cyl, u_long heads, u_long sects);

int

Delete_Chunk(struct disk *disk, struct chunk *);

void

Collapse_Disk(struct disk *disk);

int

Collapse_Chunk(struct disk *disk, struct chunk *chunk);

int

Create_Chunk(struct disk *disk, daddr_t offset, daddr_t size, chunk_e type, int subtype, u_long flags);

void

All_FreeBSD(struct disk *d, int force_all);

char *

CheckRules(struct disk *);

char **

Disk_Names(void);

void

Set_Boot_Mgr(struct disk *d, const u_char *bootmgr, const size_t bootmgr_size);

int

Set_Boot_Blocks(struct disk *d, const u_char *boot1, const u_char *boot2);

int

Write_Disk(struct disk *d);

int

Cyl_Aligned(struct disk *d, daddr_t offset);

daddr_t

Next_Cyl_Aligned(struct disk *d, daddr_t offset);

daddr_t

Prev_Cyl_Aligned(struct disk *d, daddr_t offset);

int

Track_Aligned(struct disk *d, daddr_t offset);

daddr_t

Next_Track_Aligned(struct disk *d, daddr_t offset);

daddr_t

Prev_Track_Aligned(struct disk *d, daddr_t offset);

struct chunk *

Create_Chunk_DWIM(struct disk *d, struct chunk *parent, daddr_t size, chunk_e type, int subtype, u_long flags);

int

MakeDev(struct chunk *c, const char *path);

int

MakeDevDisk(struct disk *d, const char *path);

char *

ShowChunkFlags(struct chunk *c);

const char *

chunk_name(chunk_e type);

const char *

slice_type_name(int type, int subtype);

DESCRIPTION

The libdisk library provides an interface to the low-level disk slice and partition labels. Most functions operate with arguments of the types ’struct disk’, or ’struct chunk’.

While both types are mostly opaque to the programmer, the internal structure is mentioned below for the sake of completeness.

struct disk {

char

*name;

u_long

flags;

u_long

bios_cyl;

u_long

bios_hd;

u_long

bios_sect;

u_char

*bootmgr;

u_char

*boot1;

u_char

*boot2;

struct chunk

*chunks;

u_long

sector_size;

};

The only flag value by now is ’DISK_ON_TRACK’, meaning that this disk is handled by the On-Track Disk Manager.

struct chunk {

struct chunk

*next;

struct chunk

*part;

struct disk

*disk;

daddr_t

offset;

daddr_t

size;

daddr_t

end;

char

*name;

char

*oname;

chunk_e

type;

int

subtype;

u_long

flags;

void

(*private_free)(void*);

void

*(*private_clone)(void*);

void

*private_data;

};

The ’type’ field can be one of the following values: ’whole, unknown, fat, freebsd, extended, part, unused’.

These are the valid ’flag’ values for a ’struct chunk’.

CHUNK_PAST_1024

This chunk cannot be booted from because it extends past cylinder 1024.

CHUNK_BSD_COMPAT

This chunk is in the BSD-compatibility, and has a short name too, i.e. ’wd0s4f -> wd0f’.

CHUNK_ALIGN

This chunk should be aligned.

CHUNK_IS_ROOT

This ’part’ is a rootfs, allocate partition ’a’.

CHUNK_ACTIVE

This is the active slice in the MBR.

CHUNK_FORCE_ALL

Force a dedicated disk for FreeBSD, bypassing all BIOS geometry considerations.

The ’private_data’, ’private_free’, and ’private_clone’ fields are for data private to the application, and the management thereof. If the functions are not provided, no storage management is done, cloning will just copy the pointer and freeing will just forget it.

Open_Disk() will open the named disk, and return populated tree.

Free_Disk() frees a tree made with Open_Disk() or Clone_Disk().

Debug_Disk() prints the content of the tree to stdout.

Set_Bios_Geom() sets the geometry the bios uses.

Delete_Chunk() frees a chunk of disk_space.

Collapse_Disk() and Collapse_Chunk() are experimental, do not use.

Create_Chunk() creates a chunk with the specified parameters.

All_FreeBSD() makes one FreeBSD chunk covering the entire disk; if ’force_all’ is set, bypass all BIOS geometry considerations.

CheckRules() returns ’char*’ to warnings about broken design rules in this disklayout.

Disk_Names() returns ’char**’ with all disk’s names (wd0, wd1 ...). You must free each pointer, as well as the array by hand.

Set_Boot_Mgr() sets this boot-manager for use on this disk. Gets written when Write_Disk() is called.

Set_Boot_Blocks() sets the boot-blocks for use on this disk. Gets written when Write_Disk() is called.

Write_Disk() writes all the MBRs, disklabels, bootblocks and boot managers.

Cyl_Aligned() checks if ’offset’ is aligned on a cylinder according to the BIOS geometry.

Next_Cyl_Aligned() rounds ’offset’ up to next cylinder according to the BIOS geometry.

Prev_Cyl_Aligned() rounds ’offset’ down to previous cylinder according to the BIOS geometry.

Track_Aligned() checks if ’offset’ is aligned on a track according to the BIOS geometry.

Next_Track_Aligned() rounds ’offset’ up to next track according to the BIOS geometry.

Prev_Track_Aligned() checks if ’offset’ is aligned on a track according to the BIOS geometry.

Create_Chunk_DWIM() creates a partition inside the given parent of the given size, and returns a pointer to it. The first unused chunk big enough is used.

MakeDev() makes the device nodes for this chunk.

MakeDevDisk() makes the device nodes for all chunks on this disk.

ShowChunkFlags() returns a string to show flags.

The chunk_name() function takes the enumerated chunk type and returns its name. chunk_name() replaces the old external array chunk_n.

slice_type_name() returns the name strings associated with the specified ’type’. ’subtype’. If slice_type_name() returns "unknown" for slices it isn’t familiar with.

AUTHORS

The libdisk library was written by Poul-Henning Kamp.

This manual page was written by Jörg Wunsch.

BSD March 15, 1996 BSD

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