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typedef struct Super Super;
typedef struct Group Group;
typedef struct Inode Inode;
typedef struct Dirent Dirent;
typedef struct Ext2 Ext2;
enum
{
BYTESPERSEC = 512,
SBOFF = 1024,
SBSIZE = 1024,
SUPERMAGIC = 0xEF53,
MINBLOCKSIZE = 1024,
MAXBLOCKSIZE = 4096,
ROOTINODE = 2,
FIRSTINODE = 11,
VALIDFS = 0x0001,
ERRORFS = 0x0002,
NDIRBLOCKS = 12,
INDBLOCK = NDIRBLOCKS,
DINDBLOCK = INDBLOCK+1,
TINDBLOCK = DINDBLOCK+1,
NBLOCKS = TINDBLOCK+1,
NAMELEN = 255,
/* permissions in Inode.mode */
IEXEC = 00100,
IWRITE = 0200,
IREAD = 0400,
ISVTX = 01000,
ISGID = 02000,
ISUID = 04000,
/* type in Inode.mode */
IFMT = 0170000,
IFIFO = 0010000,
IFCHR = 0020000,
IFDIR = 0040000,
IFBLK = 0060000,
IFREG = 0100000,
IFLNK = 0120000,
IFSOCK = 0140000,
IFWHT = 0160000
};
#define DIRLEN(namlen) (((namlen)+8+3)&~3)
/*
* Super block on-disk format.
*/
struct Super
{
u32int ninode; /* Inodes count */
u32int nblock; /* Blocks count */
u32int rblockcount; /* Reserved blocks count */
u32int freeblockcount; /* Free blocks count */
u32int freeinodecount; /* Free inodes count */
u32int firstdatablock; /* First Data Block */
u32int logblocksize; /* Block size */
u32int logfragsize; /* Fragment size */
u32int blockspergroup; /* # Blocks per group */
u32int fragpergroup; /* # Fragments per group */
u32int inospergroup; /* # Inodes per group */
u32int mtime; /* Mount time */
u32int wtime; /* Write time */
u16int mntcount; /* Mount count */
u16int maxmntcount; /* Maximal mount count */
u16int magic; /* Magic signature */
u16int state; /* File system state */
u16int errors; /* Behaviour when detecting errors */
u16int pad;
u32int lastcheck; /* time of last check */
u32int checkinterval; /* max. time between checks */
u32int creatoros; /* OS */
u32int revlevel; /* Revision level */
u16int defresuid; /* Default uid for reserved blocks */
u16int defresgid; /* Default gid for reserved blocks */
u32int reserved[235]; /* Padding to the end of the block */
};
/*
* Blcok group on-disk format.
*/
struct Group
{
u32int bitblock; /* Blocks bitmap block */
u32int inodebitblock; /* Inodes bitmap block */
u32int inodeaddr; /* Inodes table block */
u16int freeblockscount; /* Free blocks count */
u16int freeinodescount; /* Free inodes count */
u16int useddirscount; /* Directories count */
u16int pad;
u32int reserved[3];
};
enum
{
GroupSize = 32
};
/*
* Structure of an inode on the disk
*/
struct Inode
{
u16int mode; /* File mode */
u16int uid; /* Owner Uid */
u32int size; /* Size in bytes */
u32int atime; /* Access time */
u32int ctime; /* Creation time */
u32int mtime; /* Modification time */
u32int dtime; /* Deletion Time */
u16int gid; /* Group Id */
u16int nlink; /* Links count */
u32int nblock; /* Blocks count */
u32int flags; /* File flags */
u32int osd1;
u32int block[NBLOCKS];/* Pointers to blocks */
u32int version; /* File version (for NFS) */
u32int fileacl; /* File ACL */
u32int diracl; /* Directory ACL */
u32int faddr; /* Fragment address */
uchar osd2[12];
};
enum
{
InodeSize = 128
};
/*
* Directory entry on-disk structure.
*/
struct Dirent
{
u32int ino; /* Inode number */
u16int reclen; /* Directory entry length */
u8int namlen; /* Name length */
u8int pad;
char name[NAMELEN]; /* File name */
};
enum
{
MinDirentSize = 4+2+1+1
};
/*
* In-core fs info.
*/
struct Ext2
{
uint blocksize;
uint nblock;
uint ngroup;
uint inospergroup;
uint blockspergroup;
uint inosperblock;
uint groupaddr;
uint descperblock;
uint firstblock;
Disk *disk;
Fsys *fsys;
};
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