sysv_fs.h

GNU Hurd 源代码

	coh_ulong	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 */
};

/* Coherent free list block on disk */
struct coh_freelist_chunk {
	u16 fl_nfree;	/* number of free blocks in fl_free, <= COH_NICFREE] */
	u32  fl_free[COH_NICFREE] __packed2__;
};


/* 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" ??
					      */
		/* devices */
		dev_t i_rdev;
		/* 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 */
extern inline mode_t from_coh_imode(unsigned short mode)
{
	if (mode == COH_KLUDGE_SYMLINK_MODE)
		return (S_IFLNK | 0777);
	else
		return mode;
}
extern inline unsigned short to_coh_imode(mode_t mode)
{
	if (S_ISLNK(mode))
		return COH_KLUDGE_SYMLINK_MODE;
	else if (mode == COH_KLUDGE_SYMLINK_MODE)
		return COH_KLUDGE_NOT_SYMLINK;
	else
		return mode;
}

/* Admissible values for i_nlink: 0.._LINK_MAX */
#define XENIX_LINK_MAX	126	/* ?? */
#define SYSV_LINK_MAX	126	/* 127? 251? */
#define COH_LINK_MAX	10000	/* max number of hard links to an inode */

/* 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 */
#define FSTYPE_XENIX	1
#define FSTYPE_SYSV4	2
#define FSTYPE_SYSV2	3
#define FSTYPE_COH	4

#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)

#ifdef __KERNEL__

/* sv_get_hash_table(sb,dev,block) is equivalent to  get_hash_table(dev,block,block_size)  */
static inline struct buffer_head *
sv_get_hash_table (struct super_block *sb, kdev_t dev, unsigned int block)
{
	return get_hash_table (dev, block + sb->sv_block_base, sb->sv_block_size);
}

/* sv_getblk(sb,dev,block) is equivalent to  getblk(dev,block,block_size)  */
static inline struct buffer_head *
sv_getblk (struct super_block *sb, kdev_t dev, unsigned int block)
{
	return getblk (dev, block + sb->sv_block_base, sb->sv_block_size);
}

/* sv_bread(sb,dev,block) is equivalent to  bread(dev,block,block_size)  */
static inline struct buffer_head *
sv_bread (struct super_block *sb, kdev_t dev, unsigned int block)
{
	return bread (dev, block + sb->sv_block_base, sb->sv_block_size);
}


/*
 * Function prototypes
 */

extern struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry);
extern int sysv_create(struct inode * dir, struct dentry * dentry, int mode);
extern int sysv_mkdir(struct inode * dir, struct dentry * dentry, int mode);
extern int sysv_rmdir(struct inode * dir, struct dentry * dentry);
extern int sysv_unlink(struct inode * dir, struct dentry * dentry);
extern int sysv_symlink(struct inode * inode, struct dentry * dentry, const char * symname);
extern int sysv_link(struct dentry * old_dentry, struct inode * dir, struct dentry * dentry);
extern int sysv_mknod(struct inode * dir, struct dentry * dentry, int mode, int rdev);
extern int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
		       struct inode * new_dir, struct dentry * new_dentry);
extern struct inode * sysv_new_inode(const struct inode * dir);
extern void sysv_free_inode(struct inode * inode);
extern unsigned long sysv_count_free_inodes(struct super_block *sb);
extern int sysv_new_block(struct super_block * sb);
extern void sysv_free_block(struct super_block * sb, unsigned int block);
extern unsigned long sysv_count_free_blocks(struct super_block *sb);

extern int sysv_bmap(struct inode *,int);

extern struct buffer_head * sysv_getblk(struct inode *, unsigned int, int);
extern struct buffer_head * sysv_file_bread(struct inode *, int, int);
extern ssize_t sysv_file_read(struct file *, char *, size_t, loff_t *);

extern void sysv_truncate(struct inode *);
extern void sysv_put_super(struct super_block *);
extern struct super_block *sysv_read_super(struct super_block *,void *,int);
extern int init_sysv_fs(void);
extern void sysv_write_super(struct super_block *);
extern void sysv_read_inode(struct inode *);
extern int sysv_notify_change(struct dentry *, struct iattr *);
extern void sysv_write_inode(struct inode *);
extern int sysv_statfs(struct super_block *, struct statfs *, int);
extern int sysv_sync_inode(struct inode *);
extern int sysv_sync_file(struct file *, struct dentry *);
extern int sysv_mmap(struct file *, struct vm_area_struct *);

extern struct inode_operations sysv_file_inode_operations;
extern struct inode_operations sysv_file_inode_operations_with_bmap;
extern struct inode_operations sysv_dir_inode_operations;
extern struct inode_operations sysv_symlink_inode_operations;

#endif /* __KERNEL__ */

#endif