source: mainline/uspace/lib/minix/minix.h@ e80b1de

/*
 * Copyright (c) 2011 Maurizio Lombardi
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup fs
 * @{
 */

#ifndef _MINIX_FS_H_
#define _MINIX_FS_H_

#include <sys/types.h>

#define MFS_BLOCKSIZE           1024

/*The following block sizes are valid only on V3 filesystem*/
#define MFS_MIN_BLOCKSIZE       1024
#define MFS_MAX_BLOCKSIZE       4096

#define MFS_ROOT_INO            1
#define MFS_SUPERBLOCK          1
#define MFS_SUPERBLOCK_SIZE     1024

#define V2_NR_DIRECT_ZONES      7
#define V2_NR_INDIRECT_ZONES    3

#define V1_NR_DIRECT_ZONES      7
#define V1_NR_INDIRECT_ZONES    2

#define V1_INODES_PER_BLOCK     (MFS_BLOCKSIZE / sizeof(struct mfs_inode))
#define V2_INODES_PER_BLOCK     (MFS_BLOCKSIZE / sizeof(struct mfs2_inode))
#define V3_INODES_PER_BLOCK(bs) ((bs) / sizeof(struct mfs2_inode))

#define MFS_MAX_NAME_LEN        14
#define MFS_L_MAX_NAME_LEN      30
#define MFS3_MAX_NAME_LEN       60

#define MFS_MAGIC_V1            0x137F
#define MFS_MAGIC_V1R           0x7F13

#define MFS_MAGIC_V1L           0x138F
#define MFS_MAGIC_V1LR          0x8F13

#define MFS_MAGIC_V2            0x2468
#define MFS_MAGIC_V2R           0x6824

#define MFS_MAGIC_V2L           0x2478
#define MFS_MAGIC_V2LR          0x7824

#define MFS_MAGIC_V3            0x4D5A
#define MFS_MAGIC_V3R           0x5A4D

/*MFS V1/V2 superblock data on disk*/
struct mfs_superblock {
        /*Total number of inodes on the device*/
        uint16_t        s_ninodes;
        /*Total number of zones on the device*/
        uint16_t        s_nzones;
        /*Number of inode bitmap blocks*/
        uint16_t        s_ibmap_blocks;
        /*Number of zone bitmap blocks*/
        uint16_t        s_zbmap_blocks;
        /*First data zone on device*/
        uint16_t        s_first_data_zone;
        /*Base 2 logarithm of the zone to block ratio*/
        uint16_t        s_log2_zone_size;
        /*Maximum file size expressed in bytes*/
        uint32_t        s_max_file_size;
        /*
         *Magic number used to recognize MinixFS
         *and to detect on-disk endianness
         */
        uint16_t        s_magic;
        /*Flag used to detect FS errors*/
        uint16_t        s_state;
        /*Total number of zones on the device (V2 only)*/
        uint32_t        s_nzones2;
} __attribute__ ((packed));


/*MFS V3 superblock data on disk*/
struct mfs3_superblock {
        /*Total number of inodes on the device*/
        uint32_t        s_ninodes;
        uint16_t        s_pad0;
        /*Number of inode bitmap blocks*/
        int16_t         s_ibmap_blocks;
        /*Number of zone bitmap blocks*/
        int16_t         s_zbmap_blocks;
        /*First data zone on device*/
        uint16_t        s_first_data_zone;
        /*Base 2 logarithm of the zone to block ratio*/
        int16_t         s_log2_zone_size;
        int16_t         s_pad1;
        /*Maximum file size expressed in bytes*/
        int32_t         s_max_file_size;
        /*Total number of zones on the device*/
        uint32_t        s_nzones;
        /*
         *Magic number used to recognize MinixFS
         *and to detect on-disk endianness
         */
        int16_t         s_magic;
        int16_t         s_pad2;
        /*Filesystem block size expressed in bytes*/
        uint16_t        s_block_size;
        /*Filesystem disk format version*/
        int8_t          s_disk_version;
} __attribute__ ((packed));

/*MinixFS V1 inode structure as it is on disk*/
struct mfs_inode {
        uint16_t        i_mode;
        int16_t         i_uid;
        int32_t         i_size;
        int32_t         i_mtime;
        uint8_t         i_gid;
        uint8_t         i_nlinks;
        /*Block numbers for direct zones*/
        uint16_t        i_dzone[V1_NR_DIRECT_ZONES];
        /*Block numbers for indirect zones*/
        uint16_t        i_izone[V1_NR_INDIRECT_ZONES];
} __attribute__ ((packed));

/*MinixFS V2 inode structure as it is on disk (also valid for V3).*/
struct mfs2_inode {
        uint16_t        i_mode;
        uint16_t        i_nlinks;
        int16_t         i_uid;
        uint16_t        i_gid;
        int32_t         i_size;
        int32_t         i_atime;
        int32_t         i_mtime;
        int32_t         i_ctime;
        /*Block numbers for direct zones*/
        uint32_t        i_dzone[V2_NR_DIRECT_ZONES];
        /*Block numbers for indirect zones*/
        uint32_t        i_izone[V2_NR_INDIRECT_ZONES];
} __attribute__ ((packed));

/*MinixFS V1/V2 directory entry on-disk structure*/
struct mfs_dentry {
        uint16_t d_inum;
        char d_name[MFS_MAX_NAME_LEN];
} __attribute__ ((packed));

/*MinixFS V1/V2 with 30-char filenames (Linux variant)*/
struct mfs_l_dentry {
        uint16_t d_inum;
        char d_name[MFS_L_MAX_NAME_LEN];
} __attribute__ ((packed));

/*MinixFS V3 directory entry on-disk structure*/
struct mfs3_dentry {
        uint32_t d_inum;
        char d_name[MFS3_MAX_NAME_LEN];
} __attribute__ ((packed));


#endif

/**
 * @}
 */