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/****************************************************************************/
/* Super block table. The root file system and every mounted file system
* has an entry here. The entry holds information about the sizes of the bit
* maps and inodes. The s_ninodes field gives the number of inodes available
* for files and directories, including the root directory. Inode 0 is
* on the disk, but not used. Thus s_ninodes = 4 means that 5 bits will be
* used in the bit map, bit 0, which is always 1 and not used, and bits 1-4
* for files and directories. The disk layout is:
*
* Item # blocks
* boot block 1
* super block 1
* inode map s_imap_blocks
* zone map s_zmap_blocks
* inodes (s_ninodes + 1 + INODES_PER_BLOCK - 1)/INODES_PER_BLOCK
* unused whatever is needed to fill out the current zone
* data zones (s_nzones - s_firstdatazone) << s_log_zone_size
*
* A super_block slot is free if s_dev == NO_DEV.
*/
#define BLOCK_SIZE 1024 /* # bytes in a disk block */
/* Flag bits for i_mode in the inode. */
#define I_TYPE 0170000 /* this field gives inode type */
#define I_REGULAR 0100000 /* regular file, not dir or special */
#define I_BLOCK_SPECIAL 0060000 /* block special file */
#define I_DIRECTORY 0040000 /* file is a directory */
#define I_CHAR_SPECIAL 0020000 /* character special file */
#define I_SET_UID_BIT 0004000 /* set effective uid on exec */
#define I_SET_GID_BIT 0002000 /* set effective gid on exec */
#define ALL_MODES 0006777 /* all bits for user, group and others */
#define RWX_MODES 0000777 /* mode bits for RWX only */
#define R_BIT 0000004 /* Rwx protection bit */
#define W_BIT 0000002 /* rWx protection bit */
#define X_BIT 0000001 /* rwX protection bit */
#define I_NOT_ALLOC 0000000 /* this inode is free */
/* Type definitions */
typedef unsigned short unshort; /* must be 16-bit unsigned */
typedef unshort block_nr; /* block number */
typedef unshort inode_nr; /* inode number */
typedef unshort zone_nr; /* zone number */
typedef unshort bit_nr; /* if inode_nr & zone_nr both unshort,
then also unshort, else long */
typedef unshort sect_nr;
typedef long zone_type; /* zone size */
typedef unshort mask_bits; /* mode bits */
typedef unshort dev_nr; /* major | minor device number */
typedef char links; /* number of links to an inode */
typedef long real_time; /* real time in seconds since Jan 1, 1970 */
typedef long file_pos; /* position in, or length of, a file */
typedef short uid; /* user id */
typedef char gid; /* group id */
/* Tables sizes */
#define NR_ZONE_NUMS 9 /* # zone numbers in an inode */
#define NAME_SIZE 14 /* # bytes in a directory component */
/* Miscellaneous constants */
#define SUPER_MAGIC 0x137F /* magic number contained in super-block */
#define BOOT_BLOCK (block_nr)0 /* block number of boot block */
#define SUPER_BLOCK (block_nr)1 /* block number of super block */
#define ROOT_INODE (inode_nr)1 /* inode number for root directory */
/* Derived sizes */
#define NR_DZONE_NUM (NR_ZONE_NUMS-2) /* # zones in inode */
#define INODES_PER_BLOCK (BLOCK_SIZE/sizeof(d_inode)) /* # inodes/disk blk */
#define NR_INDIRECTS (BLOCK_SIZE/sizeof(zone_nr)) /* # zones/indir blk */
#define INTS_PER_BLOCK (BLOCK_SIZE/sizeof(int)) /* # integers/blk */
struct super_block {
inode_nr s_ninodes; /* # usable inodes on the minor device */
zone_nr s_nzones; /* total device size, including bit maps etc */
unshort s_imap_blocks; /* # of blocks used by inode bit map */
unshort s_zmap_blocks; /* # of blocks used by zone bit map */
zone_nr s_firstdatazone; /* number of first data zone */
short s_log_zone_size; /* log2 of blocks/zone */
file_pos s_max_size; /* maximum file size on this device */
short s_magic; /* magic number to recognize super-blocks */
} ;
/* Type definitions local to the File System. */
typedef struct { /* directory entry */
inode_nr d_inum; /* inode number */
char d_name[NAME_SIZE]; /* character string */
} dir_struct;
/* Declaration of the disk inode used in rw_inode(). */
typedef struct { /* disk inode. Memory inode is in "inotab.h" */
mask_bits i_mode; /* file type, protection, etc. */
uid i_uid; /* user id of the file's owner */
file_pos i_size; /* current file size in bytes */
real_time i_modtime; /* when was file data last changed */
gid i_gid; /* group number */
links i_nlinks; /* how many links to this file */
zone_nr i_zone[NR_ZONE_NUMS]; /* block nums for direct, ind, and dbl ind */
} d_inode;
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