Viewing file:  sysv_fs.h (11.57 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
#ifndef _LINUX_SYSV_FS_H
#define _LINUX_SYSV_FS_H
/*
* The SystemV/Coherent filesystem constants/structures/macros
*/
/* This code assumes
- sizeof(short) = 2, sizeof(int) = 4, sizeof(long) = 4,
- alignof(short) = 2, alignof(long) = 4.
*/
#ifdef __GNUC__
#define __packed2__ __attribute__ ((packed, aligned(2)))
#else
#error I want gcc!
#endif
#include <linux/stat.h> /* declares S_IFLNK etc. */
#include <linux/sched.h> /* declares wake_up() */
#include <linux/sysv_fs_sb.h> /* defines the sv_... shortcuts */
/* inode numbers are 16 bit */
typedef u16 sysv_ino_t;
/* Block numbers are 24 bit, sometimes stored in 32 bit.
On Coherent FS, they are always stored in PDP-11 manner: the least
significant 16 bits come last.
*/
typedef u32 sysv_zone_t;
/* Among the blocks ... */
/* Xenix FS, Coherent FS: block 0 is the boot block, block 1 the super-block.
SystemV FS: block 0 contains both the boot sector and the super-block. */
/* The first inode zone is sb->sv_firstinodezone (1 or 2). */
/* Among the inodes ... */
/* 0 is non-existent */
#define SYSV_BADBL_INO 1 /* inode of bad blocks file */
#define SYSV_ROOT_INO 2 /* inode of root directory */
/* Xenix super-block data on disk */
#define XENIX_NICINOD 100 /* number of inode cache entries */
#define XENIX_NICFREE 100 /* number of free block list chunk entries */
struct xenix_super_block {
u16 s_isize; /* index of first data zone */
u32 s_fsize __packed2__; /* total number of zones of this fs */
/* the start of the free block list: */
u16 s_nfree; /* number of free blocks in s_free, <= XENIX_NICFREE */
u32 s_free[XENIX_NICFREE]; /* first free block list chunk */
/* the cache of free inodes: */
u16 s_ninode; /* number of free inodes in s_inode, <= XENIX_NICINOD */
sysv_ino_t s_inode[XENIX_NICINOD]; /* some free inodes */
/* locks, not used by Linux: */
char s_flock; /* lock during free block list manipulation */
char s_ilock; /* lock during inode cache manipulation */
char s_fmod; /* super-block modified flag */
char s_ronly; /* flag whether fs is mounted read-only */
u32 s_time __packed2__; /* time of last super block update */
u32 s_tfree __packed2__; /* total number of free zones */
u16 s_tinode; /* total number of free inodes */
s16 s_dinfo[4]; /* device information ?? */
char s_fname[6]; /* file system volume name */
char s_fpack[6]; /* file system pack name */
char s_clean; /* set to 0x46 when filesystem is properly unmounted */
char s_fill[371];
s32 s_magic; /* version of file system */
s32 s_type; /* type of file system: 1 for 512 byte blocks
2 for 1024 byte blocks
3 for 2048 byte blocks */
};
/* SystemV FS comes in two variants:
* sysv2: System V Release 2 (e.g. Microport), structure elements aligned(2).
* sysv4: System V Release 4 (e.g. Consensys), structure elements aligned(4).
*/
#define SYSV_NICINOD 100 /* number of inode cache entries */
#define SYSV_NICFREE 50 /* number of free block list chunk entries */
/* SystemV4 super-block data on disk */
struct sysv4_super_block {
u16 s_isize; /* index of first data zone */
u16 s_pad0;
u32 s_fsize; /* total number of zones of this fs */
/* the start of the free block list: */
u16 s_nfree; /* number of free blocks in s_free, <= SYSV_NICFREE */
u16 s_pad1;
u32 s_free[SYSV_NICFREE]; /* first free block list chunk */
/* the cache of free inodes: */
u16 s_ninode; /* number of free inodes in s_inode, <= SYSV_NICINOD */
u16 s_pad2;
sysv_ino_t s_inode[SYSV_NICINOD]; /* some free inodes */
/* locks, not used by Linux: */
char s_flock; /* lock during free block list manipulation */
char s_ilock; /* lock during inode cache manipulation */
char s_fmod; /* super-block modified flag */
char s_ronly; /* flag whether fs is mounted read-only */
u32 s_time; /* time of last super block update */
s16 s_dinfo[4]; /* device information ?? */
u32 s_tfree; /* total number of free zones */
u16 s_tinode; /* total number of free inodes */
u16 s_pad3;
char s_fname[6]; /* file system volume name */
char s_fpack[6]; /* file system pack name */
s32 s_fill[12];
s32 s_state; /* file system state: 0x7c269d38-s_time means clean */
s32 s_magic; /* version of file system */
s32 s_type; /* type of file system: 1 for 512 byte blocks
2 for 1024 byte blocks */
};
/* SystemV2 super-block data on disk */
struct sysv2_super_block {
u16 s_isize; /* index of first data zone */
u32 s_fsize __packed2__; /* total number of zones of this fs */
/* the start of the free block list: */
u16 s_nfree; /* number of free blocks in s_free, <= SYSV_NICFREE */
u32 s_free[SYSV_NICFREE]; /* first free block list chunk */
/* the cache of free inodes: */
u16 s_ninode; /* number of free inodes in s_inode, <= SYSV_NICINOD */
sysv_ino_t s_inode[SYSV_NICINOD]; /* some free inodes */
/* locks, not used by Linux: */
char s_flock; /* lock during free block list manipulation */
char s_ilock; /* lock during inode cache manipulation */
char s_fmod; /* super-block modified flag */
char s_ronly; /* flag whether fs is mounted read-only */
u32 s_time __packed2__; /* time of last super block update */
s16 s_dinfo[4]; /* device information ?? */
u32 s_tfree __packed2__; /* total number of free zones */
u16 s_tinode; /* total number of free inodes */
char s_fname[6]; /* file system volume name */
char s_fpack[6]; /* file system pack name */
s32 s_fill[14];
s32 s_state; /* file system state: 0xcb096f43 means clean */
s32 s_magic; /* version of file system */
s32 s_type; /* type of file system: 1 for 512 byte blocks
2 for 1024 byte blocks */
};
/* V7 super-block data on disk */
#define V7_NICINOD 100 /* number of inode cache entries */
#define V7_NICFREE 50 /* number of free block list chunk entries */
struct v7_super_block {
u16 s_isize; /* index of first data zone */
u32 s_fsize __packed2__; /* total number of zones of this fs */
/* the start of the free block list: */
u16 s_nfree; /* number of free blocks in s_free, <= V7_NICFREE */
u32 s_free[V7_NICFREE]; /* first free block list chunk */
/* the cache of free inodes: */
u16 s_ninode; /* number of free inodes in s_inode, <= V7_NICINOD */
sysv_ino_t s_inode[V7_NICINOD]; /* some free inodes */
/* locks, not used by Linux or V7: */
char s_flock; /* lock during free block list manipulation */
char s_ilock; /* lock during inode cache manipulation */
char s_fmod; /* super-block modified flag */
char s_ronly; /* flag whether fs is mounted read-only */
u32 s_time __packed2__; /* time of last super block update */
/* the following fields are not maintained by V7: */
u32 s_tfree __packed2__; /* total number of free zones */
u16 s_tinode; /* total number of free inodes */
u16 s_m; /* interleave factor */
u16 s_n; /* interleave factor */
char s_fname[6]; /* file system name */
char s_fpack[6]; /* file system pack name */
};
/* Coherent super-block data on disk */
#define COH_NICINOD 100 /* number of inode cache entries */
#define COH_NICFREE 64 /* number of free block list chunk entries */
struct coh_super_block {
u16 s_isize; /* index of first data zone */
u32 s_fsize __packed2__; /* total number of zones of this fs */
/* the start of the free block list: */
u16 s_nfree; /* number of free blocks in s_free, <= COH_NICFREE */
u32 s_free[COH_NICFREE] __packed2__; /* first free block list chunk */
/* the cache of free inodes: */
u16 s_ninode; /* number of free inodes in s_inode, <= COH_NICINOD */
sysv_ino_t s_inode[COH_NICINOD]; /* some free inodes */
/* locks, not used by Linux: */
char s_flock; /* lock during free block list manipulation */
char s_ilock; /* lock during inode cache manipulation */
char s_fmod; /* super-block modified flag */
char s_ronly; /* flag whether fs is mounted read-only */
u32 s_time __packed2__; /* time of last super block update */
u32 s_tfree __packed2__; /* total number of free zones */
u16 s_tinode; /* total number of free inodes */
u16 s_interleave_m; /* interleave factor */
u16 s_interleave_n;
char s_fname[6]; /* file system volume name */
char s_fpack[6]; /* file system pack name */
u32 s_unique; /* zero, not used */
};
/* SystemV/Coherent inode data on disk */
struct sysv_inode {
u16 i_mode;
u16 i_nlink;
u16 i_uid;
u16 i_gid;
u32 i_size;
union { /* directories, regular files, ... */
unsigned char i_addb[3*(10+1+1+1)+1]; /* zone numbers: max. 10 data blocks,
* then 1 indirection block,
* then 1 double indirection block,
* then 1 triple indirection block.
* Then maybe a "file generation number" ??
*/
/* named pipes on Coherent */
struct {
char p_addp[30];
s16 p_pnc;
s16 p_prx;
s16 p_pwx;
} i_p;
} i_a;
u32 i_atime; /* time of last access */
u32 i_mtime; /* time of last modification */
u32 i_ctime; /* time of creation */
};
/* The admissible values for i_mode are listed in <linux/stat.h> :
* #define S_IFMT 00170000 mask for type
* #define S_IFREG 0100000 type = regular file
* #define S_IFBLK 0060000 type = block device
* #define S_IFDIR 0040000 type = directory
* #define S_IFCHR 0020000 type = character device
* #define S_IFIFO 0010000 type = named pipe
* #define S_ISUID 0004000 set user id
* #define S_ISGID 0002000 set group id
* #define S_ISVTX 0001000 save swapped text even after use
* Additionally for SystemV:
* #define S_IFLNK 0120000 type = symbolic link
* #define S_IFNAM 0050000 type = XENIX special named file ??
* Additionally for Coherent:
* #define S_IFMPB 0070000 type = multiplexed block device ??
* #define S_IFMPC 0030000 type = multiplexed character device ??
*
* Since Coherent doesn't know about symbolic links, we use a kludgey
* implementation of symbolic links: i_mode = COH_KLUDGE_SYMLINK_MODE
* denotes a symbolic link. When a regular file should get this mode by
* accident, it is automatically converted to COH_KLUDGE_NOT_SYMLINK.
* We use S_IFREG because only regular files (and Coherent pipes...) can have
* data blocks with arbitrary contents associated with them, and S_ISVTX
* ("save swapped text after use") because it is unused on both Linux and
* Coherent: Linux does much more intelligent paging, and Coherent hasn't
* virtual memory at all.
* Same trick for Xenix.
*/
#define COH_KLUDGE_SYMLINK_MODE (S_IFREG | S_ISVTX)
#define COH_KLUDGE_NOT_SYMLINK (S_IFREG | S_ISVTX | S_IRUSR) /* force read access */
/* Admissible values for i_nlink: 0.._LINK_MAX */
enum {
XENIX_LINK_MAX = 126, /* ?? */
SYSV_LINK_MAX = 126, /* 127? 251? */
V7_LINK_MAX = 126, /* ?? */
COH_LINK_MAX = 10000,
};
/* The number of inodes per block is
sb->sv_inodes_per_block = block_size / sizeof(struct sysv_inode) */
/* The number of indirect pointers per block is
sb->sv_ind_per_block = block_size / sizeof(u32) */
/* SystemV/Coherent directory entry on disk */
#define SYSV_NAMELEN 14 /* max size of name in struct sysv_dir_entry */
struct sysv_dir_entry {
sysv_ino_t inode;
char name[SYSV_NAMELEN]; /* up to 14 characters, the rest are zeroes */
};
#define SYSV_DIRSIZE sizeof(struct sysv_dir_entry) /* size of every directory entry */
/* Operations */
/* ========== */
/* identify the FS in memory */
enum {
FSTYPE_NONE = 0,
FSTYPE_XENIX,
FSTYPE_SYSV4,
FSTYPE_SYSV2,
FSTYPE_COH,
FSTYPE_V7,
FSTYPE_AFS,
FSTYPE_END,
};
#define SYSV_MAGIC_BASE 0x012FF7B3
#define XENIX_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_XENIX)
#define SYSV4_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV4)
#define SYSV2_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV2)
#define COH_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_COH)
#endif
|