/*
* format of cache on disk
*/
typedef struct Dptr Dptr;
typedef struct Dahdr Dahdr;
typedef struct Dalloc Dalloc;
typedef struct Fphdr Fphdr;
typedef struct Fptr Fptr;
typedef struct Inode Inode;
typedef struct Dihdr Dihdr;
typedef struct Dinode Dinode;
enum
{
Amagic= 0xbebeefed, /* allocation block magic */
Imagic= 0xbadc00ce, /* inode block magic */
BtoUL= 8*sizeof(ulong),/* bits in a ulong */
CACHENAMELEN= 128
};
#define Indbno 0x80000000 /* indirect block */
#define Notabno 0xFFFFFFFF /* not a block number */
/*
* Allocation blocks at the begining of the disk. There are
* enough of these blocks to supply 1 bit for each block on the
* disk;
*/
struct Dahdr
{
ulong magic;
ulong bsize; /* logical block size */
char name[CACHENAMELEN];
short nab; /* number of allocation blocks */
};
struct Dalloc
{
Dahdr;
ulong bits[1];
};
/*
* A pointer to disk data
*/
struct Dptr
{
ulong fbno; /* file block number */
ulong bno; /* disk block number */
ushort start; /* offset into block of valid data */
ushort end; /* offset into block after valid data */
};
