xref: /linux/include/linux/sysv_fs.h (revision 498495dba268b20e8eadd7fe93c140c68b6cc9d2)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SYSV_FS_H
3 #define _LINUX_SYSV_FS_H
4 
5 #define __packed2__	__attribute__((packed, aligned(2)))
6 
7 
8 #ifndef __KERNEL__
9 typedef u16 __fs16;
10 typedef u32 __fs16;
11 #endif
12 
13 /* inode numbers are 16 bit */
14 typedef __fs16 sysv_ino_t;
15 
16 /* Block numbers are 24 bit, sometimes stored in 32 bit.
17    On Coherent FS, they are always stored in PDP-11 manner: the least
18    significant 16 bits come last. */
19 typedef __fs32 sysv_zone_t;
20 
21 /* 0 is non-existent */
22 #define SYSV_BADBL_INO	1	/* inode of bad blocks file */
23 #define SYSV_ROOT_INO	2	/* inode of root directory */
24 
25 
26 /* Xenix super-block data on disk */
27 #define XENIX_NICINOD	100	/* number of inode cache entries */
28 #define XENIX_NICFREE	100	/* number of free block list chunk entries */
29 struct xenix_super_block {
30 	__fs16		s_isize; /* index of first data zone */
31 	__fs32		s_fsize __packed2__; /* total number of zones of this fs */
32 	/* the start of the free block list: */
33 	__fs16		s_nfree;	/* number of free blocks in s_free, <= XENIX_NICFREE */
34 	sysv_zone_t	s_free[XENIX_NICFREE]; /* first free block list chunk */
35 	/* the cache of free inodes: */
36 	__fs16		s_ninode; /* number of free inodes in s_inode, <= XENIX_NICINOD */
37 	sysv_ino_t	s_inode[XENIX_NICINOD]; /* some free inodes */
38 	/* locks, not used by Linux: */
39 	char		s_flock;	/* lock during free block list manipulation */
40 	char		s_ilock;	/* lock during inode cache manipulation */
41 	char		s_fmod;		/* super-block modified flag */
42 	char		s_ronly;	/* flag whether fs is mounted read-only */
43 	__fs32		s_time __packed2__; /* time of last super block update */
44 	__fs32		s_tfree __packed2__; /* total number of free zones */
45 	__fs16		s_tinode;	/* total number of free inodes */
46 	__fs16		s_dinfo[4];	/* device information ?? */
47 	char		s_fname[6];	/* file system volume name */
48 	char		s_fpack[6];	/* file system pack name */
49 	char		s_clean;	/* set to 0x46 when filesystem is properly unmounted */
50 	char		s_fill[371];
51 	s32		s_magic;	/* version of file system */
52 	__fs32		s_type;		/* type of file system: 1 for 512 byte blocks
53 								2 for 1024 byte blocks
54 								3 for 2048 byte blocks */
55 
56 };
57 
58 /*
59  * SystemV FS comes in two variants:
60  * sysv2: System V Release 2 (e.g. Microport), structure elements aligned(2).
61  * sysv4: System V Release 4 (e.g. Consensys), structure elements aligned(4).
62  */
63 #define SYSV_NICINOD	100	/* number of inode cache entries */
64 #define SYSV_NICFREE	50	/* number of free block list chunk entries */
65 
66 /* SystemV4 super-block data on disk */
67 struct sysv4_super_block {
68 	__fs16	s_isize;	/* index of first data zone */
69 	u16	s_pad0;
70 	__fs32	s_fsize;	/* total number of zones of this fs */
71 	/* the start of the free block list: */
72 	__fs16	s_nfree;	/* number of free blocks in s_free, <= SYSV_NICFREE */
73 	u16	s_pad1;
74 	sysv_zone_t	s_free[SYSV_NICFREE]; /* first free block list chunk */
75 	/* the cache of free inodes: */
76 	__fs16	s_ninode;	/* number of free inodes in s_inode, <= SYSV_NICINOD */
77 	u16	s_pad2;
78 	sysv_ino_t     s_inode[SYSV_NICINOD]; /* some free inodes */
79 	/* locks, not used by Linux: */
80 	char	s_flock;	/* lock during free block list manipulation */
81 	char	s_ilock;	/* lock during inode cache manipulation */
82 	char	s_fmod;		/* super-block modified flag */
83 	char	s_ronly;	/* flag whether fs is mounted read-only */
84 	__fs32	s_time;		/* time of last super block update */
85 	__fs16	s_dinfo[4];	/* device information ?? */
86 	__fs32	s_tfree;	/* total number of free zones */
87 	__fs16	s_tinode;	/* total number of free inodes */
88 	u16	s_pad3;
89 	char	s_fname[6];	/* file system volume name */
90 	char	s_fpack[6];	/* file system pack name */
91 	s32	s_fill[12];
92 	__fs32	s_state;	/* file system state: 0x7c269d38-s_time means clean */
93 	s32	s_magic;	/* version of file system */
94 	__fs32	s_type;		/* type of file system: 1 for 512 byte blocks
95 								2 for 1024 byte blocks */
96 };
97 
98 /* SystemV2 super-block data on disk */
99 struct sysv2_super_block {
100 	__fs16	s_isize; 		/* index of first data zone */
101 	__fs32	s_fsize __packed2__;	/* total number of zones of this fs */
102 	/* the start of the free block list: */
103 	__fs16	s_nfree;		/* number of free blocks in s_free, <= SYSV_NICFREE */
104 	sysv_zone_t s_free[SYSV_NICFREE];	/* first free block list chunk */
105 	/* the cache of free inodes: */
106 	__fs16	s_ninode;		/* number of free inodes in s_inode, <= SYSV_NICINOD */
107 	sysv_ino_t     s_inode[SYSV_NICINOD]; /* some free inodes */
108 	/* locks, not used by Linux: */
109 	char	s_flock;		/* lock during free block list manipulation */
110 	char	s_ilock;		/* lock during inode cache manipulation */
111 	char	s_fmod;			/* super-block modified flag */
112 	char	s_ronly;		/* flag whether fs is mounted read-only */
113 	__fs32	s_time __packed2__;	/* time of last super block update */
114 	__fs16	s_dinfo[4];		/* device information ?? */
115 	__fs32	s_tfree __packed2__;	/* total number of free zones */
116 	__fs16	s_tinode;		/* total number of free inodes */
117 	char	s_fname[6];		/* file system volume name */
118 	char	s_fpack[6];		/* file system pack name */
119 	s32	s_fill[14];
120 	__fs32	s_state;		/* file system state: 0xcb096f43 means clean */
121 	s32	s_magic;		/* version of file system */
122 	__fs32	s_type;			/* type of file system: 1 for 512 byte blocks
123 								2 for 1024 byte blocks */
124 };
125 
126 /* V7 super-block data on disk */
127 #define V7_NICINOD     100     /* number of inode cache entries */
128 #define V7_NICFREE     50      /* number of free block list chunk entries */
129 struct v7_super_block {
130 	__fs16 s_isize;        /* index of first data zone */
131 	__fs32 s_fsize __packed2__; /* total number of zones of this fs */
132 	/* the start of the free block list: */
133 	__fs16 s_nfree;        /* number of free blocks in s_free, <= V7_NICFREE */
134 	sysv_zone_t s_free[V7_NICFREE]; /* first free block list chunk */
135 	/* the cache of free inodes: */
136 	__fs16 s_ninode;       /* number of free inodes in s_inode, <= V7_NICINOD */
137 	sysv_ino_t      s_inode[V7_NICINOD]; /* some free inodes */
138 	/* locks, not used by Linux or V7: */
139 	char    s_flock;        /* lock during free block list manipulation */
140 	char    s_ilock;        /* lock during inode cache manipulation */
141 	char    s_fmod;         /* super-block modified flag */
142 	char    s_ronly;        /* flag whether fs is mounted read-only */
143 	__fs32  s_time __packed2__; /* time of last super block update */
144 	/* the following fields are not maintained by V7: */
145 	__fs32  s_tfree __packed2__; /* total number of free zones */
146 	__fs16  s_tinode;       /* total number of free inodes */
147 	__fs16  s_m;            /* interleave factor */
148 	__fs16  s_n;            /* interleave factor */
149 	char    s_fname[6];     /* file system name */
150 	char    s_fpack[6];     /* file system pack name */
151 };
152 /* Constants to aid sanity checking */
153 /* This is not a hard limit, nor enforced by v7 kernel. It's actually just
154  * the limit used by Seventh Edition's ls, though is high enough to assume
155  * that no reasonable file system would have that much entries in root
156  * directory. Thus, if we see anything higher, we just probably got the
157  * endiannes wrong. */
158 #define V7_NFILES	1024
159 /* The disk addresses are three-byte (despite direct block addresses being
160  * aligned word-wise in inode). If the most significant byte is non-zero,
161  * something is most likely wrong (not a filesystem, bad bytesex). */
162 #define V7_MAXSIZE	0x00ffffff
163 
164 /* Coherent super-block data on disk */
165 #define COH_NICINOD	100	/* number of inode cache entries */
166 #define COH_NICFREE	64	/* number of free block list chunk entries */
167 struct coh_super_block {
168 	__fs16		s_isize;	/* index of first data zone */
169 	__fs32		s_fsize __packed2__; /* total number of zones of this fs */
170 	/* the start of the free block list: */
171 	__fs16 s_nfree;	/* number of free blocks in s_free, <= COH_NICFREE */
172 	sysv_zone_t	s_free[COH_NICFREE] __packed2__; /* first free block list chunk */
173 	/* the cache of free inodes: */
174 	__fs16		s_ninode;	/* number of free inodes in s_inode, <= COH_NICINOD */
175 	sysv_ino_t	s_inode[COH_NICINOD]; /* some free inodes */
176 	/* locks, not used by Linux: */
177 	char		s_flock;	/* lock during free block list manipulation */
178 	char		s_ilock;	/* lock during inode cache manipulation */
179 	char		s_fmod;		/* super-block modified flag */
180 	char		s_ronly;	/* flag whether fs is mounted read-only */
181 	__fs32		s_time __packed2__; /* time of last super block update */
182 	__fs32		s_tfree __packed2__; /* total number of free zones */
183 	__fs16		s_tinode;	/* total number of free inodes */
184 	__fs16		s_interleave_m;	/* interleave factor */
185 	__fs16		s_interleave_n;
186 	char		s_fname[6];	/* file system volume name */
187 	char		s_fpack[6];	/* file system pack name */
188 	__fs32		s_unique;	/* zero, not used */
189 };
190 
191 /* SystemV/Coherent inode data on disk */
192 struct sysv_inode {
193 	__fs16 i_mode;
194 	__fs16 i_nlink;
195 	__fs16 i_uid;
196 	__fs16 i_gid;
197 	__fs32 i_size;
198 	u8  i_data[3*(10+1+1+1)];
199 	u8  i_gen;
200 	__fs32 i_atime;	/* time of last access */
201 	__fs32 i_mtime;	/* time of last modification */
202 	__fs32 i_ctime;	/* time of creation */
203 };
204 
205 /* SystemV/Coherent directory entry on disk */
206 #define SYSV_NAMELEN	14	/* max size of name in struct sysv_dir_entry */
207 struct sysv_dir_entry {
208 	sysv_ino_t inode;
209 	char name[SYSV_NAMELEN]; /* up to 14 characters, the rest are zeroes */
210 };
211 
212 #define SYSV_DIRSIZE	sizeof(struct sysv_dir_entry)	/* size of every directory entry */
213 
214 #endif /* _LINUX_SYSV_FS_H */
215