sys/lib/libsa/minixfs3.h

   1 /*      $NetBSD: minixfs3.h,v 1.5 2013/06/23 07:28:36 dholland Exp $ */
   2
   3 /*-
   4  * Copyright (c) 2012
   5  *      Vrije Universiteit, Amsterdam, The Netherlands. All rights reserved.
   6  *
   7  * Author: Evgeniy Ivanov
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
  19  * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  20  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS BE
  22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  28  * POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #ifndef MINIX_FS_3_H
  32 #define MINIX_FS_3_H
  33
  34 FS_DEF(minixfs3);
  35
  36 #if !defined(__minix)
  37 typedef uint32_t zone_t;
  38 typedef uint16_t zone1_t;
  39 typedef uint32_t block_t;
  40 #endif /* !defined(__minix) */
  41
  42 #define NR_DZONES       7       /* # direct zone numbers in an inode */
  43 #define NR_TZONES       10      /* total # zone numbers in an inode */
  44 #define NIADDR          2       /* Indirect addresses in inode */
  45
  46 struct mfs_dinode {
  47         uint16_t  mdi_mode;     /* file type, protection, etc. */
  48         uint16_t  mdi_nlinks;   /* how many links to this file */
  49         int16_t   mdi_uid;      /* user id of the file's owner */
  50         uint16_t  mdi_gid;      /* group number */
  51         uint32_t  mdi_size;     /* current file size in bytes */
  52         uint32_t  mdi_atime;    /* time of last access */
  53         uint32_t  mdi_mtime;    /* when was file data last changed */
  54         uint32_t  mdi_ctime;    /* when was inode itself changed */
  55         zone_t    mdi_zone[NR_TZONES]; /* zone numbers for direct, ind, and
  56                                                 dbl ind */
  57 };
  58
  59 /* Maximum Minix MFS on-disk directory filename.
  60  * MFS uses 'struct direct' to write and parse
  61  * directory entries, so this can't be changed
  62  * without breaking filesystems.
  63  */
  64 #define MFS_DIRSIZ      60
  65
  66 struct mfs_direct {
  67         uint32_t  mfsd_ino;
  68         char      mfsd_name[MFS_DIRSIZ];
  69 } __packed;
  70
  71 struct mfs_sblock {
  72         uint32_t  mfs_ninodes;          /* # usable inodes on the minor device */
  73         zone1_t   mfs_nzones;           /* total device size, including bit maps etc */
  74         int16_t   mfs_imap_blocks;      /* # of blocks used by inode bit map */
  75         int16_t   mfs_zmap_blocks;      /* # of blocks used by zone bit map */
  76         zone1_t   mfs_firstdatazone_old;/* number of first data zone (small) */
  77         int16_t   mfs_log_zone_size;    /* log2 of blocks/zone */
  78         int16_t   mfs_pad;              /* try to avoid compiler-dependent padding */
  79         int32_t   mfs_max_size;         /* maximum file size on this device */
  80         zone_t    mfs_zones;            /* number of zones (replaces s_nzones in V2) */
  81         int16_t   mfs_magic;            /* magic number to recognize super-blocks */
  82         int16_t   mfs_pad2;             /* try to avoid compiler-dependent padding */
  83         uint16_t  mfs_block_size;       /* block size in bytes. */
  84         char      mfs_disk_version;     /* filesystem format sub-version */
  85
  86   /* The following items are only used when the super_block is in memory,
  87    * mfs_inodes_per_block must be the firs one (see SBSIZE)
  88    */
  89         unsigned mfs_inodes_per_block;  /* precalculated from magic number */
  90         zone_t   mfs_firstdatazone;     /* number of first data zone (big) */
  91         int32_t  mfs_bshift;            /* ``lblkno'' calc of logical blkno */
  92         int32_t  mfs_bmask;             /* ``blkoff'' calc of blk offsets */
  93         int64_t  mfs_qbmask;            /* ~fs_bmask - for use with quad size */
  94         int32_t  mfs_fsbtodb;           /* fsbtodb and dbtofsb shift constant */
  95 };
  96
  97 #define LOG_MINBSIZE    10
  98 #define MINBSIZE        (1 << LOG_MINBSIZE)
  99
 100 #define SUPER_MAGIC     0x4d5a  /* magic # for MFSv3 file systems */
 101
 102 #define ROOT_INODE      ((uint32_t) 1)  /* inode number for root directory */
 103 #define SUPER_BLOCK_OFF (1024)          /* bytes offset */
 104 #define START_BLOCK     ((block_t) 2)   /* first fs block (not counting SB) */
 105
 106 /* # bytes/dir entry */
 107 #define DIR_ENTRY_SIZE          sizeof(struct mfs_direct)
 108 /* # dir entries/blk */
 109 #define NR_DIR_ENTRIES(fs)      ((fs)->mfs_block_size/DIR_ENTRY_SIZE)
 110 /* mfs_sblock on-disk part size */
 111 #define SBSIZE                  offsetof(struct mfs_sblock, mfs_inodes_per_block)
 112
 113 #define ZONE_NUM_SIZE           sizeof(zone_t) /* # bytes in zone  */
 114 #define INODE_SIZE              sizeof(struct mfs_dinode) /* bytes in dsk ino */
 115 /* # zones/indir block */
 116 #define MFS_NINDIR(fs)          ((fs)->mfs_block_size/ZONE_NUM_SIZE)
 117
 118 #define NO_ZONE                 ((zone_t) 0)    /* absence of a zone number */
 119 #define NO_BLOCK                ((block_t) 0)   /* absence of a block number */
 120
 121 /* Turn file system block numbers into disk block addresses */
 122 #define MFS_FSBTODB(fs, b)      ((b) << (fs)->mfs_fsbtodb)
 123
 124 #define ino_to_fsba(fs, x)                                              \
 125         (((x) - 1) / (fs)->mfs_inodes_per_block +                       \
 126         START_BLOCK + (fs)->mfs_imap_blocks + (fs)->mfs_zmap_blocks)
 127 #define ino_to_fsbo(fs, x)      (((x) - 1) % (fs)->mfs_inodes_per_block)
 128
 129 /*
 130  * MFS metadatas are stored in little-endian byte order. These macros
 131  * helps reading theses metadatas.
 132  */
 133 #if BYTE_ORDER == LITTLE_ENDIAN
 134 #       define fs2h16(x) (x)
 135 #       define fs2h32(x) (x)
 136 #       define mfs_sbload(old, new)     \
 137                 memcpy((new), (old), SBSIZE);
 138 #       define mfs_iload(old, new)      \
 139                 memcpy((new),(old),sizeof(struct mfs_dinode))
 140 #else
 141 void minixfs3_sb_bswap(struct mfs_sblock *, struct mfs_sblock *);
 142 void minixfs3_i_bswap(struct mfs_dinode *, struct mfs_dinode *);
 143 #       define fs2h16(x) bswap16(x)
 144 #       define fs2h32(x) bswap32(x)
 145 #       define mfs_sbload(old, new) minixfs3_sb_bswap((old), (new))
 146 #       define mfs_iload(old, new) minixfs3_i_bswap((old), (new))
 147 #endif /* BYTE_ORDER == LITTLE_ENDIAN */
 148
 149 /*
 150  * The following macros optimize certain frequently calculated
 151  * quantities by using shifts and masks in place of divisions
 152  * modulos and multiplications.
 153  */
 154 #define mfs_blkoff(fs, loc)     /* calculates (loc % fs->mfs_bsize) */ \
 155         ((loc) & (fs)->mfs_qbmask)
 156 #define mfs_lblkno(fs, loc)     /* calculates (loc / fs->mfs_bsize) */ \
 157         ((loc) >> (fs)->mfs_bshift)
 158
 159 /* Flag bits for i_mode in the inode. */
 160 #define I_TYPE          0170000 /* this field gives inode type */
 161 #define I_UNIX_SOCKET   0140000 /* unix domain socket */
 162 #define I_SYMBOLIC_LINK 0120000 /* file is a symbolic link */
 163 #define I_REGULAR       0100000 /* regular file, not dir or special */
 164 #define I_BLOCK_SPECIAL 0060000 /* block special file */
 165 #define I_DIRECTORY     0040000 /* file is a directory */
 166 #define I_CHAR_SPECIAL  0020000 /* character special file */
 167 #define I_NAMED_PIPE    0010000 /* named pipe (FIFO) */
 168 #define I_SET_UID_BIT   0004000 /* set effective uid_t on exec */
 169 #define I_SET_GID_BIT   0002000 /* set effective gid_t on exec */
 170 #define I_SET_STCKY_BIT 0001000 /* sticky bit */
 171 #define ALL_MODES       0007777 /* all bits for user, group and others */
 172 #define RWX_MODES       0000777 /* mode bits for RWX only */
 173 #define R_BIT           0000004 /* Rwx protection bit */
 174 #define W_BIT           0000002 /* rWx protection bit */
 175 #define X_BIT           0000001 /* rwX protection bit */
 176 #define I_NOT_ALLOC     0000000 /* this inode is free */
 177
 178 #endif /* MINIX_FS_3_H */