omfs_fs.h

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#ifndef _OMFS_FS_H
#define _OMFS_FS_H

/* OMFS On-disk structures */

#define OMFS_MAGIC 0xC2993D87
#define OMFS_IMAGIC 0xD2

#define OMFS_DIR 'D'
#define OMFS_FILE 'F'
#define OMFS_INODE_NORMAL 'e'
#define OMFS_INODE_CONTINUATION 'c'
#define OMFS_INODE_SYSTEM 's'
#define OMFS_NAMELEN 256
#define OMFS_DIR_START 0x1b8
#define OMFS_EXTENT_START 0x1d0
#define OMFS_EXTENT_CONT 0x40
#define OMFS_XOR_COUNT 19
#define OMFS_MAX_BLOCK_SIZE 8192
#define OMFS_MAX_CLUSTER_SIZE 8

struct omfs_super_block {
    char s_fill1[256];
    __be64 s_root_block;        /* block number of omfs_root_block */
    __be64 s_num_blocks;        /* total number of FS blocks */
    __be32 s_magic;         /* OMFS_MAGIC */
    __be32 s_blocksize;     /* size of a block */
    __be32 s_mirrors;       /* # of mirrors of system blocks */
    __be32 s_sys_blocksize;     /* size of non-data blocks */
};

struct omfs_header {
    __be64 h_self;          /* FS block where this is located */
    __be32 h_body_size;     /* size of useful data after header */
    __be16 h_crc;           /* crc-ccitt of body_size bytes */
    char h_fill1[2];
    u8 h_version;           /* version, always 1 */
    char h_type;            /* OMFS_INODE_X */
    u8 h_magic;         /* OMFS_IMAGIC */
    u8 h_check_xor;         /* XOR of header bytes before this */
    __be32 h_fill2;
};

struct omfs_root_block {
    struct omfs_header r_head;  /* header */
    __be64 r_fill1;
    __be64 r_num_blocks;        /* total number of FS blocks */
    __be64 r_root_dir;      /* block # of root directory */
    __be64 r_bitmap;        /* block # of free space bitmap */
    __be32 r_blocksize;     /* size of a block */
    __be32 r_clustersize;       /* size allocated for data blocks */
    __be64 r_mirrors;       /* # of mirrors of system blocks */
    char r_name[OMFS_NAMELEN];  /* partition label */
};

struct omfs_inode {
    struct omfs_header i_head;  /* header */
    __be64 i_parent;        /* parent containing this inode */
    __be64 i_sibling;       /* next inode in hash bucket */
    __be64 i_ctime;         /* ctime, in milliseconds */
    char i_fill1[35];
    char i_type;            /* OMFS_[DIR,FILE] */
    __be32 i_fill2;
    char i_fill3[64];
    char i_name[OMFS_NAMELEN];  /* filename */
    __be64 i_size;          /* size of file, in bytes */
};

struct omfs_extent_entry {
    __be64 e_cluster;       /* start location of a set of blocks */
    __be64 e_blocks;        /* number of blocks after e_cluster */
};

struct omfs_extent {
    __be64 e_next;          /* next extent table location */
    __be32 e_extent_count;      /* total # extents in this table */
    __be32 e_fill;
    struct omfs_extent_entry e_entry;   /* start of extent entries */
};

#endif