root/include/linux/bfs_fs.h

INCLUDED FROM

/*
 *      include/linux/bfs_fs.h - BFS data structures on disk.
 *      Copyright (C) 1999 Tigran Aivazian <tigran@veritas.com>
 */

#ifndef _LINUX_BFS_FS_H
#define _LINUX_BFS_FS_H

#define BFS_BSIZE_BITS          9
#define BFS_BSIZE               (1<<BFS_BSIZE_BITS)

#define BFS_MAGIC               0x1BADFACE
#define BFS_ROOT_INO            2
#define BFS_INODES_PER_BLOCK    8

/* SVR4 vnode type values (bfs_inode->i_vtype) */
#define BFS_VDIR 2L
#define BFS_VREG 1L


/* BFS inode layout on disk */
struct bfs_inode {
        __le16 i_ino;
        __u16 i_unused;
        __le32 i_sblock;
        __le32 i_eblock;
        __le32 i_eoffset;
        __le32 i_vtype;
        __le32 i_mode;
        __le32 i_uid;
        __le32 i_gid;
        __le32 i_nlink;
        __le32 i_atime;
        __le32 i_mtime;
        __le32 i_ctime;
        __u32 i_padding[4];
};

#define BFS_NAMELEN             14      
#define BFS_DIRENT_SIZE         16
#define BFS_DIRS_PER_BLOCK      32

struct bfs_dirent {
        __le16 ino;
        char name[BFS_NAMELEN];
};

/* BFS superblock layout on disk */
struct bfs_super_block {
        __le32 s_magic;
        __le32 s_start;
        __le32 s_end;
        __le32 s_from;
        __le32 s_to;
        __s32 s_bfrom;
        __s32 s_bto;
        char  s_fsname[6];
        char  s_volume[6];
        __u32 s_padding[118];
};


#define BFS_OFF2INO(offset) \
        ((((offset) - BFS_BSIZE) / sizeof(struct bfs_inode)) + BFS_ROOT_INO)

#define BFS_INO2OFF(ino) \
        ((__u32)(((ino) - BFS_ROOT_INO) * sizeof(struct bfs_inode)) + BFS_BSIZE)
#define BFS_NZFILESIZE(ip) \
        ((le32_to_cpu((ip)->i_eoffset) + 1) -  le32_to_cpu((ip)->i_sblock) * BFS_BSIZE)

#define BFS_FILESIZE(ip) \
        ((ip)->i_sblock == 0 ? 0 : BFS_NZFILESIZE(ip))

#define BFS_FILEBLOCKS(ip) \
        ((ip)->i_sblock == 0 ? 0 : (le32_to_cpu((ip)->i_eblock) + 1) -  le32_to_cpu((ip)->i_sblock))
#define BFS_UNCLEAN(bfs_sb, sb) \
        ((le32_to_cpu(bfs_sb->s_from) != -1) && (le32_to_cpu(bfs_sb->s_to) != -1) && !(sb->s_flags & MS_RDONLY))


#endif  /* _LINUX_BFS_FS_H */