Subversion Repositories c0or1k

/*

 * The disk layout of our simple unix-like filesystem.

 *

 * Copyright (C) 2007, 2008 Bahadir Balban

 */

#ifndef __C0FS_LAYOUT_H__

#define __C0FS_LAYOUT_H__

#include <l4lib/types.h>

#include <l4/lib/list.h>

#include <l4/macros.h>

#include <l4/config.h>

#include INC_GLUE(memory.h)

/*

 *

 * Filesystem layout:

 *

 * |---------------|

 * |    Group 0    |

 * |---------------|

 * |    Group 1    |

 * |---------------|

 * |      ...      |

 * |---------------|

 * |    Group n    |

 * |---------------|

 *

 *

 * Group layout:

 *

 * |---------------|

 * |  Superblock   |

 * |---------------|

 * |  Inode table  |

 * |---------------|

 * |  Data blocks  |

 * |---------------|

 *

 * or

 *

 * |---------------|

 * |  Data blocks  |

 * |---------------|

 *

 */

#define BLOCK_SIZE              PAGE_SIZE

#define BLOCK_BITS              PAGE_BITS

#define GROUP_SIZE              SZ_8MB

#define INODE_TABLE_SIZE        ((GROUP_SIZE / BLOCK_SIZE) / 2)

#define INODE_BITMAP_SIZE       (INODE_TABLE_SIZE >> 5)

struct sfs_superblock {

        u32 magic;              /* Filesystem magic number */

        u64 fssize;             /* Total size of filesystem */

        u32 total;              /* To */

        u32 groupmap[];         /* Bitmap of all fs groups */

};

struct sfs_group_table {

        u32 total;

        u32 free;

        u32 groupmap[];

};

struct sfs_inode_table {

        u32 total;

        u32 free;

        u32 inodemap[INODE_BITMAP_SIZE];

        struct sfs_inode inode[INODE_TABLE_SIZE];

};

/*

 * The purpose of an inode:

 *

 * 1) Uniquely identify a file or a directory.

 * 2) Keep file/directory metadata.

 * 3) Provide access means to file blocks/directory contents.

 */

#define INODE_DIRECT_BLOCKS     5

struct sfs_inode_blocks {

        int  szidx;             /* Direct array index size */

        unsigned long indirect;

        unsigned long indirect2;

        unsigned long indirect3;

        unsigned long direct[];

};

struct sfs_inode {

        u32 unum;       /* Unit number this inode is in */

        u32 inum;       /* Inode number */

        u32 mode;       /* File permissions */

        u32 owner;      /* File owner */

        u64 atime;      /* Last access time */

        u64 mtime;      /* Last content modification */

        u64 ctime;      /* Last inode modification */

        u64 size;       /* Size of contents */

        struct sfs_inode_blocks blocks;

} __attribute__ ((__packed__));

struct sfs_dentry {

        u32 inum;       /* Inode number */

        u32 nlength;    /* Name length */

        u8  name[];     /* Name string */

} __attribute__ ((__packed__));

void sfs_register_type(struct link *);

#endif /* __C0FS_LAYOUT_H__ */