blob: 04e0b6713cc573f64b42fa194f6e03cc7ac341d2 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
// on-disk file system format
#define BSIZE 512 // block size
// sector 1 (2nd sector)
struct superblock{
uint size;
uint nblocks;
uint ninodes;
};
#define NADDRS (NDIRECT+1)
#define NDIRECT 12
#define INDIRECT 12
#define NINDIRECT (BSIZE / sizeof(uint))
#define MAXFILE (NDIRECT + NINDIRECT)
struct dinode {
short type;
short major;
short minor;
short nlink;
uint size;
uint addrs[NADDRS];
};
#define T_DIR 1
#define T_FILE 2
#define T_DEV 3
// sector 0 is unused, sector 1 is superblock, inodes start at sector 2
#define IPB (BSIZE / sizeof(struct dinode))
#define IBLOCK(inum) (inum / IPB + 2) // start of inode
#define BPB (BSIZE*8)
#define BBLOCK(b,ninodes) (b/BPB + (ninodes/IPB) + 3) // start of bitmap
#define DIRSIZ 14
struct dirent {
ushort inum;
char name[DIRSIZ];
};
|