xref: /minix/sys/lib/libsa/minixfs3.h (revision 84d9c625)
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 */
179