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      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 typedef uint32_t zone_t;
     37 typedef uint16_t zone1_t;
     38 typedef uint32_t block_t;
     39 
     40 #define NR_DZONES	7	/* # direct zone numbers in an inode */
     41 #define NR_TZONES	10	/* total # zone numbers in an inode */
     42 #define NIADDR		2       /* Indirect addresses in inode */
     43 
     44 struct mfs_dinode {
     45 	uint16_t  mdi_mode;	/* file type, protection, etc. */
     46 	uint16_t  mdi_nlinks;	/* how many links to this file */
     47 	int16_t   mdi_uid;	/* user id of the file's owner */
     48 	uint16_t  mdi_gid;	/* group number */
     49 	uint32_t  mdi_size;	/* current file size in bytes */
     50 	uint32_t  mdi_atime;	/* time of last access */
     51 	uint32_t  mdi_mtime;	/* when was file data last changed */
     52 	uint32_t  mdi_ctime;	/* when was inode itself changed */
     53 	zone_t    mdi_zone[NR_TZONES]; /* zone numbers for direct, ind, and
     54 						dbl ind */
     55 };
     56 
     57 /* Maximum Minix MFS on-disk directory filename.
     58  * MFS uses 'struct direct' to write and parse
     59  * directory entries, so this can't be changed
     60  * without breaking filesystems.
     61  */
     62 #define MFS_DIRSIZ	60
     63 
     64 struct mfs_direct {
     65 	uint32_t  mfsd_ino;
     66 	char      mfsd_name[MFS_DIRSIZ];
     67 } __packed;
     68 
     69 struct mfs_sblock {
     70 	uint32_t  mfs_ninodes;		/* # usable inodes on the minor device */
     71 	zone1_t   mfs_nzones;		/* total device size, including bit maps etc */
     72 	int16_t   mfs_imap_blocks;	/* # of blocks used by inode bit map */
     73 	int16_t   mfs_zmap_blocks;	/* # of blocks used by zone bit map */
     74 	zone1_t   mfs_firstdatazone_old;/* number of first data zone (small) */
     75 	int16_t   mfs_log_zone_size;	/* log2 of blocks/zone */
     76 	int16_t   mfs_pad;		/* try to avoid compiler-dependent padding */
     77 	int32_t   mfs_max_size;		/* maximum file size on this device */
     78 	zone_t    mfs_zones;		/* number of zones (replaces s_nzones in V2) */
     79 	int16_t   mfs_magic;		/* magic number to recognize super-blocks */
     80 	int16_t   mfs_pad2;		/* try to avoid compiler-dependent padding */
     81 	uint16_t  mfs_block_size;	/* block size in bytes. */
     82 	char      mfs_disk_version;	/* filesystem format sub-version */
     83 
     84   /* The following items are only used when the super_block is in memory,
     85    * mfs_inodes_per_block must be the firs one (see SBSIZE)
     86    */
     87 	unsigned mfs_inodes_per_block;	/* precalculated from magic number */
     88 	zone_t   mfs_firstdatazone;	/* number of first data zone (big) */
     89 	int32_t  mfs_bshift;		/* ``lblkno'' calc of logical blkno */
     90 	int32_t  mfs_bmask;		/* ``blkoff'' calc of blk offsets */
     91 	int64_t  mfs_qbmask;		/* ~fs_bmask - for use with quad size */
     92 	int32_t  mfs_fsbtodb;		/* fsbtodb and dbtofsb shift constant */
     93 };
     94 
     95 #define LOG_MINBSIZE	10
     96 #define MINBSIZE	(1 << LOG_MINBSIZE)
     97 
     98 #define SUPER_MAGIC	0x4d5a	/* magic # for MFSv3 file systems */
     99 
    100 #define ROOT_INODE	((uint32_t) 1)	/* inode number for root directory */
    101 #define SUPER_BLOCK_OFF (1024)		/* bytes offset */
    102 #define START_BLOCK	((block_t) 2)	/* first fs block (not counting SB) */
    103 
    104 /* # bytes/dir entry */
    105 #define DIR_ENTRY_SIZE		sizeof(struct mfs_direct)
    106 /* # dir entries/blk */
    107 #define NR_DIR_ENTRIES(fs)	((fs)->mfs_block_size/DIR_ENTRY_SIZE)
    108 /* mfs_sblock on-disk part size */
    109 #define SBSIZE			offsetof(struct mfs_sblock, mfs_inodes_per_block)
    110 
    111 #define ZONE_NUM_SIZE		sizeof(zone_t) /* # bytes in zone  */
    112 #define INODE_SIZE		sizeof(struct mfs_dinode) /* bytes in dsk ino */
    113 /* # zones/indir block */
    114 #define MFS_NINDIR(fs)		((fs)->mfs_block_size/ZONE_NUM_SIZE)
    115 
    116 #define NO_ZONE			((zone_t) 0)	/* absence of a zone number */
    117 #define NO_BLOCK		((block_t) 0)	/* absence of a block number */
    118 
    119 /* Turn file system block numbers into disk block addresses */
    120 #define MFS_FSBTODB(fs, b)	((b) << (fs)->mfs_fsbtodb)
    121 
    122 #define	ino_to_fsba(fs, x)						\
    123 	(((x) - 1) / (fs)->mfs_inodes_per_block +			\
    124 	START_BLOCK + (fs)->mfs_imap_blocks + (fs)->mfs_zmap_blocks)
    125 #define	ino_to_fsbo(fs, x)	(((x) - 1) % (fs)->mfs_inodes_per_block)
    126 
    127 /*
    128  * MFS metadatas are stored in little-endian byte order. These macros
    129  * helps reading theses metadatas.
    130  */
    131 #if BYTE_ORDER == LITTLE_ENDIAN
    132 #	define fs2h16(x) (x)
    133 #	define fs2h32(x) (x)
    134 #	define mfs_sbload(old, new)	\
    135 		memcpy((new), (old), SBSIZE);
    136 #	define mfs_iload(old, new)	\
    137 		memcpy((new),(old),sizeof(struct mfs_dinode))
    138 #else
    139 void minixfs3_sb_bswap(struct mfs_sblock *, struct mfs_sblock *);
    140 void minixfs3_i_bswap(struct mfs_dinode *, struct mfs_dinode *);
    141 #	define fs2h16(x) bswap16(x)
    142 #	define fs2h32(x) bswap32(x)
    143 #	define mfs_sbload(old, new) minixfs3_sb_bswap((old), (new))
    144 #	define mfs_iload(old, new) minixfs3_i_bswap((old), (new))
    145 #endif /* BYTE_ORDER == LITTLE_ENDIAN */
    146 
    147 /*
    148  * The following macros optimize certain frequently calculated
    149  * quantities by using shifts and masks in place of divisions
    150  * modulos and multiplications.
    151  */
    152 #define mfs_blkoff(fs, loc)	/* calculates (loc % fs->mfs_bsize) */ \
    153 	((loc) & (fs)->mfs_qbmask)
    154 #define mfs_lblkno(fs, loc)	/* calculates (loc / fs->mfs_bsize) */ \
    155 	((loc) >> (fs)->mfs_bshift)
    156 
    157 /* Flag bits for i_mode in the inode. */
    158 #define I_TYPE          0170000 /* this field gives inode type */
    159 #define I_UNIX_SOCKET   0140000 /* unix domain socket */
    160 #define I_SYMBOLIC_LINK 0120000 /* file is a symbolic link */
    161 #define I_REGULAR       0100000 /* regular file, not dir or special */
    162 #define I_BLOCK_SPECIAL 0060000 /* block special file */
    163 #define I_DIRECTORY     0040000 /* file is a directory */
    164 #define I_CHAR_SPECIAL  0020000 /* character special file */
    165 #define I_NAMED_PIPE    0010000 /* named pipe (FIFO) */
    166 #define I_SET_UID_BIT   0004000 /* set effective uid_t on exec */
    167 #define I_SET_GID_BIT   0002000 /* set effective gid_t on exec */
    168 #define I_SET_STCKY_BIT 0001000 /* sticky bit */
    169 #define ALL_MODES       0007777 /* all bits for user, group and others */
    170 #define RWX_MODES       0000777 /* mode bits for RWX only */
    171 #define R_BIT           0000004 /* Rwx protection bit */
    172 #define W_BIT           0000002 /* rWx protection bit */
    173 #define X_BIT           0000001 /* rwX protection bit */
    174 #define I_NOT_ALLOC     0000000 /* this inode is free */
    175 
    176 #endif /* MINIX_FS_3_H */
    177