437 lines
16 KiB
C
437 lines
16 KiB
C
#ifndef _LINUX_SYSV_FS_H
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#define _LINUX_SYSV_FS_H
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/*
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* The SystemV/Coherent filesystem constants/structures/macros
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*/
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/* This code assumes
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- a little endian processor like 386,
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- sizeof(short) = 2, sizeof(int) = 4, sizeof(long) = 4,
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- alignof(short) = 2, alignof(long) = 4.
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*/
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#ifdef __GNUC__
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#define __packed2__ __attribute__ ((packed, aligned(2)))
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#else
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#error I want gcc!
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#endif
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#include <linux/stat.h> /* declares S_IFLNK etc. */
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#include <linux/sched.h> /* declares wake_up() */
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#include <linux/sysv_fs_sb.h> /* defines the sv_... shortcuts */
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/* Layout on disk */
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/* ============== */
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/* The block size is sb->sv_block_size which may be smaller than BLOCK_SIZE. */
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/* zones (= data allocation units) are blocks */
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/* On Coherent FS, 32 bit quantities are stored using (I quote the Coherent
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manual) a "canonical byte ordering". This is the PDP-11 byte ordering:
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x = 2^24 * byte3 + 2^16 * byte2 + 2^8 * byte1 + byte0 is stored
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as { byte2, byte3, byte0, byte1 }. We need conversions.
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*/
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typedef unsigned long coh_ulong;
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static inline coh_ulong to_coh_ulong (unsigned long x)
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{
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return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
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}
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static inline unsigned long from_coh_ulong (coh_ulong x)
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{
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return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
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}
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/* inode numbers are 16 bit */
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typedef unsigned short sysv_ino_t;
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/* Block numbers are 24 bit, sometimes stored in 32 bit.
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On Coherent FS, they are always stored in PDP-11 manner: the least
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significant 16 bits come last.
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*/
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typedef unsigned long sysv_zone_t;
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/* Among the blocks ... */
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/* Xenix FS, Coherent FS: block 0 is the boot block, block 1 the super-block.
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SystemV FS: block 0 contains both the boot sector and the super-block. */
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/* The first inode zone is sb->sv_firstinodezone (1 or 2). */
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/* Among the inodes ... */
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/* 0 is non-existent */
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#define SYSV_BADBL_INO 1 /* inode of bad blocks file */
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#define SYSV_ROOT_INO 2 /* inode of root directory */
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/* Xenix super-block data on disk */
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#define XENIX_NICINOD 100 /* number of inode cache entries */
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#define XENIX_NICFREE 100 /* number of free block list chunk entries */
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struct xenix_super_block {
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unsigned short s_isize; /* index of first data zone */
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unsigned long s_fsize __packed2__; /* total number of zones of this fs */
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/* the start of the free block list: */
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unsigned short s_nfree; /* number of free blocks in s_free, <= XENIX_NICFREE */
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unsigned long s_free[XENIX_NICFREE]; /* first free block list chunk */
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/* the cache of free inodes: */
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unsigned short s_ninode; /* number of free inodes in s_inode, <= XENIX_NICINOD */
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sysv_ino_t s_inode[XENIX_NICINOD]; /* some free inodes */
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/* locks, not used by Linux: */
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char s_flock; /* lock during free block list manipulation */
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char s_ilock; /* lock during inode cache manipulation */
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char s_fmod; /* super-block modified flag */
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char s_ronly; /* flag whether fs is mounted read-only */
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unsigned long s_time __packed2__; /* time of last super block update */
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unsigned long s_tfree __packed2__; /* total number of free zones */
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unsigned short s_tinode; /* total number of free inodes */
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short s_dinfo[4]; /* device information ?? */
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char s_fname[6]; /* file system volume name */
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char s_fpack[6]; /* file system pack name */
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char s_clean; /* set to 0x46 when filesystem is properly unmounted */
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char s_fill[371];
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long s_magic; /* version of file system */
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long s_type; /* type of file system: 1 for 512 byte blocks
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2 for 1024 byte blocks */
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};
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/* Xenix free list block on disk */
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struct xenix_freelist_chunk {
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unsigned short fl_nfree; /* number of free blocks in fl_free, <= XENIX_NICFREE] */
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unsigned long fl_free[XENIX_NICFREE] __packed2__;
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};
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/* SystemV FS comes in two variants:
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* sysv2: System V Release 2 (e.g. Microport), structure elements aligned(2).
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* sysv4: System V Release 4 (e.g. Consensys), structure elements aligned(4).
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*/
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#define SYSV_NICINOD 100 /* number of inode cache entries */
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#define SYSV_NICFREE 50 /* number of free block list chunk entries */
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/* SystemV4 super-block data on disk */
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struct sysv4_super_block {
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unsigned short s_isize; /* index of first data zone */
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unsigned long s_fsize; /* total number of zones of this fs */
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/* the start of the free block list: */
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unsigned short s_nfree; /* number of free blocks in s_free, <= SYSV_NICFREE */
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unsigned long s_free[SYSV_NICFREE]; /* first free block list chunk */
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/* the cache of free inodes: */
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unsigned short s_ninode; /* number of free inodes in s_inode, <= SYSV_NICINOD */
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sysv_ino_t s_inode[SYSV_NICINOD]; /* some free inodes */
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/* locks, not used by Linux: */
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char s_flock; /* lock during free block list manipulation */
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char s_ilock; /* lock during inode cache manipulation */
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char s_fmod; /* super-block modified flag */
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char s_ronly; /* flag whether fs is mounted read-only */
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unsigned long s_time; /* time of last super block update */
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short s_dinfo[4]; /* device information ?? */
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unsigned long s_tfree; /* total number of free zones */
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unsigned short s_tinode; /* total number of free inodes */
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char s_fname[6]; /* file system volume name */
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char s_fpack[6]; /* file system pack name */
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long s_fill[12];
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long s_state; /* file system state */
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long s_magic; /* version of file system */
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long s_type; /* type of file system: 1 for 512 byte blocks
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2 for 1024 byte blocks */
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};
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/* SystemV4 free list block on disk */
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struct sysv4_freelist_chunk {
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unsigned short fl_nfree; /* number of free blocks in fl_free, <= SYSV_NICFREE] */
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unsigned long fl_free[SYSV_NICFREE];
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};
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/* SystemV2 super-block data on disk */
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struct sysv2_super_block {
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unsigned short s_isize; /* index of first data zone */
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unsigned long s_fsize __packed2__; /* total number of zones of this fs */
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/* the start of the free block list: */
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unsigned short s_nfree; /* number of free blocks in s_free, <= SYSV_NICFREE */
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unsigned long s_free[SYSV_NICFREE]; /* first free block list chunk */
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/* the cache of free inodes: */
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unsigned short s_ninode; /* number of free inodes in s_inode, <= SYSV_NICINOD */
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sysv_ino_t s_inode[SYSV_NICINOD]; /* some free inodes */
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/* locks, not used by Linux: */
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char s_flock; /* lock during free block list manipulation */
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char s_ilock; /* lock during inode cache manipulation */
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char s_fmod; /* super-block modified flag */
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char s_ronly; /* flag whether fs is mounted read-only */
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unsigned long s_time __packed2__; /* time of last super block update */
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short s_dinfo[4]; /* device information ?? */
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unsigned long s_tfree __packed2__; /* total number of free zones */
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unsigned short s_tinode; /* total number of free inodes */
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char s_fname[6]; /* file system volume name */
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char s_fpack[6]; /* file system pack name */
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long s_fill[14];
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long s_state; /* file system state */
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long s_magic; /* version of file system */
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long s_type; /* type of file system: 1 for 512 byte blocks
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2 for 1024 byte blocks */
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};
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/* SystemV2 free list block on disk */
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struct sysv2_freelist_chunk {
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unsigned short fl_nfree; /* number of free blocks in fl_free, <= SYSV_NICFREE] */
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unsigned long fl_free[SYSV_NICFREE] __packed2__;
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};
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/* Coherent super-block data on disk */
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#define COH_NICINOD 100 /* number of inode cache entries */
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#define COH_NICFREE 64 /* number of free block list chunk entries */
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struct coh_super_block {
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unsigned short s_isize; /* index of first data zone */
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coh_ulong s_fsize __packed2__; /* total number of zones of this fs */
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/* the start of the free block list: */
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unsigned short s_nfree; /* number of free blocks in s_free, <= COH_NICFREE */
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coh_ulong s_free[COH_NICFREE] __packed2__; /* first free block list chunk */
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/* the cache of free inodes: */
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unsigned short s_ninode; /* number of free inodes in s_inode, <= COH_NICINOD */
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sysv_ino_t s_inode[COH_NICINOD]; /* some free inodes */
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/* locks, not used by Linux: */
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char s_flock; /* lock during free block list manipulation */
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char s_ilock; /* lock during inode cache manipulation */
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char s_fmod; /* super-block modified flag */
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char s_ronly; /* flag whether fs is mounted read-only */
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coh_ulong s_time __packed2__; /* time of last super block update */
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coh_ulong s_tfree __packed2__; /* total number of free zones */
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unsigned short s_tinode; /* total number of free inodes */
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unsigned short s_interleave_m; /* interleave factor */
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unsigned short s_interleave_n;
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char s_fname[6]; /* file system volume name */
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char s_fpack[6]; /* file system pack name */
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unsigned long s_unique; /* zero, not used */
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};
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/* Coherent free list block on disk */
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struct coh_freelist_chunk {
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unsigned short fl_nfree; /* number of free blocks in fl_free, <= COH_NICFREE] */
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unsigned long fl_free[COH_NICFREE] __packed2__;
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};
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/* SystemV/Coherent inode data on disk */
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struct sysv_inode {
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unsigned short i_mode;
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unsigned short i_nlink;
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unsigned short i_uid;
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unsigned short i_gid;
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unsigned long i_size;
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union { /* directories, regular files, ... */
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char i_addb[3*(10+1+1+1)+1]; /* zone numbers: max. 10 data blocks,
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* then 1 indirection block,
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* then 1 double indirection block,
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* then 1 triple indirection block.
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* Then maybe a "file generation number" ??
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*/
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/* devices */
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dev_t i_rdev;
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/* named pipes on Coherent */
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struct {
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char p_addp[30];
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short p_pnc;
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short p_prx;
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short p_pwx;
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} i_p;
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} i_a;
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unsigned long i_atime; /* time of last access */
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unsigned long i_mtime; /* time of last modification */
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unsigned long i_ctime; /* time of creation */
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};
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/* The admissible values for i_mode are listed in <linux/stat.h> :
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* #define S_IFMT 00170000 mask for type
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* #define S_IFREG 0100000 type = regular file
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* #define S_IFBLK 0060000 type = block device
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* #define S_IFDIR 0040000 type = directory
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* #define S_IFCHR 0020000 type = character device
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* #define S_IFIFO 0010000 type = named pipe
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* #define S_ISUID 0004000 set user id
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* #define S_ISGID 0002000 set group id
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* #define S_ISVTX 0001000 save swapped text even after use
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* Additionally for SystemV:
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* #define S_IFLNK 0120000 type = symbolic link
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* #define S_IFNAM 0050000 type = XENIX special named file ??
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* Additionally for Coherent:
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* #define S_IFMPB 0070000 type = multiplexed block device ??
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* #define S_IFMPC 0030000 type = multiplexed character device ??
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*
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* Since Coherent doesn't know about symbolic links, we use a kludgey
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* implementation of symbolic links: i_mode = COH_KLUDGE_SYMLINK_MODE
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* denotes a symbolic link. When a regular file should get this mode by
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* accident, it is automatically converted to COH_KLUDGE_NOT_SYMLINK.
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* We use S_IFREG because only regular files (and Coherent pipes...) can have
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* data blocks with arbitrary contents associated with them, and S_ISVTX
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* ("save swapped text after use") because it is unused on both Linux and
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* Coherent: Linux does much more intelligent paging, and Coherent hasn't
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* virtual memory at all.
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* Same trick for Xenix.
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*/
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#define COH_KLUDGE_SYMLINK_MODE (S_IFREG | S_ISVTX)
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#define COH_KLUDGE_NOT_SYMLINK (S_IFREG | S_ISVTX | S_IRUSR) /* force read access */
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extern inline mode_t from_coh_imode(unsigned short mode)
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{
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if (mode == COH_KLUDGE_SYMLINK_MODE)
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return (S_IFLNK | 0777);
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else
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return mode;
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}
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extern inline unsigned short to_coh_imode(mode_t mode)
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{
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if (S_ISLNK(mode))
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return COH_KLUDGE_SYMLINK_MODE;
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else if (mode == COH_KLUDGE_SYMLINK_MODE)
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return COH_KLUDGE_NOT_SYMLINK;
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else
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return mode;
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}
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/* Admissible values for i_nlink: 0.._LINK_MAX */
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#define XENIX_LINK_MAX 126 /* ?? */
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#define SYSV_LINK_MAX 126 /* 127? 251? */
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#define COH_LINK_MAX 10000 /* max number of hard links to an inode */
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/* The number of inodes per block is
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sb->sv_inodes_per_block = block_size / sizeof(struct sysv_inode) */
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/* The number of indirect pointers per block is
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sb->sv_ind_per_block = block_size / sizeof(unsigned long) */
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/* SystemV/Coherent directory entry on disk */
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#define SYSV_NAMELEN 14 /* max size of name in struct sysv_dir_entry */
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struct sysv_dir_entry {
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sysv_ino_t inode;
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char name[SYSV_NAMELEN]; /* up to 14 characters, the rest are zeroes */
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};
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#define SYSV_DIRSIZE sizeof(struct sysv_dir_entry) /* size of every directory entry */
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/* Operations */
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/* ========== */
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/* identify the FS in memory */
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#define FSTYPE_XENIX 1
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#define FSTYPE_SYSV4 2
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#define FSTYPE_SYSV2 3
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#define FSTYPE_COH 4
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#define SYSV_MAGIC_BASE 0x012FF7B3
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#define XENIX_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_XENIX)
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#define SYSV4_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV4)
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#define SYSV2_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV2)
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#define COH_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_COH)
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/* Because the block size may be smaller than 1024 (which is the unit used by
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the disk drivers and the buffer code), many functions must return a pointer
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to the buffer data additionally to the buffer head pointer.
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*/
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#if 0
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struct bh_data {
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struct buffer_head * bh;
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char * bh_data;
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};
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#endif
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/* sysv_bread(sb,dev,block,...) would be equivalent to
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bread(dev,block,BLOCK_SIZE)
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if the block size were always 1024, which is the only one bread() supports.
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*/
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static inline struct buffer_head *
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sysv_bread (struct super_block *sb, int dev, unsigned int block, char* * data)
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{
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struct buffer_head *bh;
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if (!(bh = bread (dev, (block >> sb->sv_block_size_ratio_bits) + sb->sv_block_base, BLOCK_SIZE)))
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return NULL;
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*data = bh->b_data + ((block & sb->sv_block_size_ratio_1) << sb->sv_block_size_bits);
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return bh;
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}
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/* locks - protect against simultaneous write and truncate */
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extern void _coh_wait_on_inode (struct inode * inode);
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extern inline void coh_wait_on_inode (struct inode * inode)
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{
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if (inode->u.sysv_i.i_lock)
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_coh_wait_on_inode(inode);
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}
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extern inline void coh_lock_inode (struct inode * inode)
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{
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if (inode->u.sysv_i.i_lock)
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_coh_wait_on_inode(inode);
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inode->u.sysv_i.i_lock = 1;
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}
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extern inline void coh_unlock_inode (struct inode * inode)
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{
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inode->u.sysv_i.i_lock = 0;
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wake_up(&inode->u.sysv_i.i_wait);
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}
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/*
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* Function prototypes
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*/
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extern int sysv_lookup(struct inode * dir,const char * name, int len,
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struct inode ** result);
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extern int sysv_create(struct inode * dir,const char * name, int len, int mode,
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struct inode ** result);
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extern int sysv_mkdir(struct inode * dir, const char * name, int len, int mode);
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extern int sysv_rmdir(struct inode * dir, const char * name, int len);
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extern int sysv_unlink(struct inode * dir, const char * name, int len);
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extern int sysv_symlink(struct inode * inode, const char * name, int len,
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const char * symname);
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extern int sysv_link(struct inode * oldinode, struct inode * dir, const char * name, int len);
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extern int sysv_mknod(struct inode * dir, const char * name, int len, int mode, int rdev);
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extern int sysv_rename(struct inode * old_dir, const char * old_name, int old_len,
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struct inode * new_dir, const char * new_name, int new_len);
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extern struct inode * sysv_new_inode(const struct inode * dir);
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extern void sysv_free_inode(struct inode * inode);
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extern unsigned long sysv_count_free_inodes(struct super_block *sb);
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extern int sysv_new_block(struct super_block * sb);
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extern void sysv_free_block(struct super_block * sb, unsigned int block);
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extern unsigned long sysv_count_free_blocks(struct super_block *sb);
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extern int sysv_bmap(struct inode *,int);
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extern struct buffer_head * sysv_getblk(struct inode *, unsigned int, int, char* *);
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extern struct buffer_head * sysv_file_bread(struct inode *, int, int, char* *);
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extern void sysv_truncate(struct inode *);
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extern void sysv_put_super(struct super_block *);
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extern struct super_block *sysv_read_super(struct super_block *,void *,int);
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extern void sysv_write_super(struct super_block *);
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extern void sysv_read_inode(struct inode *);
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extern int sysv_notify_change(int,struct inode *);
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extern void sysv_write_inode(struct inode *);
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extern void sysv_put_inode(struct inode *);
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extern void sysv_statfs(struct super_block *, struct statfs *);
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extern int sysv_sync_inode(struct inode *);
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extern int sysv_sync_file(struct inode *, struct file *);
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#if 0
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extern int sysv_mmap(struct inode *, struct file *, unsigned long, size_t, int, unsigned long);
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#endif
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extern struct inode_operations sysv_file_inode_operations;
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extern struct inode_operations sysv_file_inode_operations_with_bmap;
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extern struct inode_operations sysv_dir_inode_operations;
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extern struct inode_operations sysv_symlink_inode_operations;
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#endif
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