44 lines
814 B
C
44 lines
814 B
C
// on-disk file system format
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#define BSIZE 512 // block size
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// sector 1 (2nd sector)
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struct superblock{
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uint size;
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uint nblocks;
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uint ninodes;
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};
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#define NADDRS NDIRECT+1
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#define NDIRECT 12
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#define INDIRECT 12
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#define NINDIRECT (BSIZE / sizeof(uint))
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#define MAXFILE (NDIRECT + NINDIRECT)
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struct dinode {
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short type;
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short major;
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short minor;
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short nlink;
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uint size;
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uint addrs[NADDRS];
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};
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#define T_DIR 1
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#define T_FILE 2
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#define T_DEV 3
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// sector 0 is unused, sector 1 is superblock, inodes start at sector 2
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#define IPB (BSIZE / sizeof(struct dinode))
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#define IBLOCK(inum) (inum / IPB + 2) // start of inode
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#define BPB (BSIZE*8)
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#define BBLOCK(b,ninodes) (b/BPB + (ninodes/IPB) + 3) // start of bitmap
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#define DIRSIZ 14
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struct dirent {
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ushort inum;
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char name[DIRSIZ];
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};
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