efs.h

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/*
 * Copyright (c) 1999 Al Smith
 *
 * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
 * Portions derived from IRIX header files (c) 1988 Silicon Graphics
 */
#ifndef _EFS_EFS_H_
#define _EFS_EFS_H_

#include <linux/fs.h>
#include <asm/uaccess.h>

#define EFS_VERSION "1.0a"

static const char cprt[] = "EFS: "EFS_VERSION" - (c) 1999 Al Smith <[email protected]>";


/* 1 block is 512 bytes */
#define EFS_BLOCKSIZE_BITS  9
#define EFS_BLOCKSIZE       (1 << EFS_BLOCKSIZE_BITS)

typedef int32_t     efs_block_t;
typedef uint32_t    efs_ino_t;

#define EFS_DIRECTEXTENTS   12

/*
 * layout of an extent, in memory and on disk. 8 bytes exactly.
 */
typedef union extent_u {
    unsigned char raw[8];
    struct extent_s {
        unsigned int    ex_magic:8; /* magic # (zero) */
        unsigned int    ex_bn:24;   /* basic block */
        unsigned int    ex_length:8;    /* numblocks in this extent */
        unsigned int    ex_offset:24;   /* logical offset into file */
    } cooked;
} efs_extent;

typedef struct edevs {
    __be16      odev;
    __be32      ndev;
} efs_devs;

/*
 * extent based filesystem inode as it appears on disk.  The efs inode
 * is exactly 128 bytes long.
 */
struct  efs_dinode {
    __be16      di_mode;    /* mode and type of file */
    __be16      di_nlink;   /* number of links to file */
    __be16      di_uid;     /* owner's user id */
    __be16      di_gid;     /* owner's group id */
    __be32      di_size;    /* number of bytes in file */
    __be32      di_atime;   /* time last accessed */
    __be32      di_mtime;   /* time last modified */
    __be32      di_ctime;   /* time created */
    __be32      di_gen;     /* generation number */
    __be16      di_numextents;  /* # of extents */
    u_char      di_version; /* version of inode */
    u_char      di_spare;   /* spare - used by AFS */
    union di_addr {
        efs_extent  di_extents[EFS_DIRECTEXTENTS];
        efs_devs    di_dev; /* device for IFCHR/IFBLK */
    } di_u;
};

/* efs inode storage in memory */
struct efs_inode_info {
    int     numextents;
    int     lastextent;

    efs_extent  extents[EFS_DIRECTEXTENTS];
    struct inode    vfs_inode;
};

#include <linux/efs_fs_sb.h>

#define EFS_DIRBSIZE_BITS   EFS_BLOCKSIZE_BITS
#define EFS_DIRBSIZE        (1 << EFS_DIRBSIZE_BITS)

struct efs_dentry {
    __be32      inode;
    unsigned char   namelen;
    char        name[3];
};

#define EFS_DENTSIZE    (sizeof(struct efs_dentry) - 3 + 1)
#define EFS_MAXNAMELEN  ((1 << (sizeof(char) * 8)) - 1)

#define EFS_DIRBLK_HEADERSIZE   4
#define EFS_DIRBLK_MAGIC    0xbeef  /* moo */

struct efs_dir {
    __be16  magic;
    unsigned char   firstused;
    unsigned char   slots;

    unsigned char   space[EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE];
};

#define EFS_MAXENTS \
    ((EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE) / \
     (EFS_DENTSIZE + sizeof(char)))

#define EFS_SLOTAT(dir, slot) EFS_REALOFF((dir)->space[slot])

#define EFS_REALOFF(offset) ((offset << 1))


static inline struct efs_inode_info *INODE_INFO(struct inode *inode)
{
    return container_of(inode, struct efs_inode_info, vfs_inode);
}

static inline struct efs_sb_info *SUPER_INFO(struct super_block *sb)
{
    return sb->s_fs_info;
}

struct statfs;
struct fid;

extern const struct inode_operations efs_dir_inode_operations;
extern const struct file_operations efs_dir_operations;
extern const struct address_space_operations efs_symlink_aops;

extern struct inode *efs_iget(struct super_block *, unsigned long);
extern efs_block_t efs_map_block(struct inode *, efs_block_t);
extern int efs_get_block(struct inode *, sector_t, struct buffer_head *, int);

extern struct dentry *efs_lookup(struct inode *, struct dentry *, unsigned int);
extern struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid,
        int fh_len, int fh_type);
extern struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
        int fh_len, int fh_type);
extern struct dentry *efs_get_parent(struct dentry *);
extern int efs_bmap(struct inode *, int);

#endif /* _EFS_EFS_H_ */