xref: /linux/fs/efs/efs.h (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * Copyright (c) 1999 Al Smith
3  *
4  * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
5  * Portions derived from IRIX header files (c) 1988 Silicon Graphics
6  */
7 #ifndef _EFS_EFS_H_
8 #define _EFS_EFS_H_
9 
10 #ifdef pr_fmt
11 #undef pr_fmt
12 #endif
13 
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 
16 #include <linux/fs.h>
17 #include <linux/uaccess.h>
18 
19 #define EFS_VERSION "1.0a"
20 
21 static const char cprt[] = "EFS: "EFS_VERSION" - (c) 1999 Al Smith <Al.Smith@aeschi.ch.eu.org>";
22 
23 
24 /* 1 block is 512 bytes */
25 #define	EFS_BLOCKSIZE_BITS	9
26 #define	EFS_BLOCKSIZE		(1 << EFS_BLOCKSIZE_BITS)
27 
28 typedef	int32_t		efs_block_t;
29 typedef uint32_t	efs_ino_t;
30 
31 #define	EFS_DIRECTEXTENTS	12
32 
33 /*
34  * layout of an extent, in memory and on disk. 8 bytes exactly.
35  */
36 typedef union extent_u {
37 	unsigned char raw[8];
38 	struct extent_s {
39 		unsigned int	ex_magic:8;	/* magic # (zero) */
40 		unsigned int	ex_bn:24;	/* basic block */
41 		unsigned int	ex_length:8;	/* numblocks in this extent */
42 		unsigned int	ex_offset:24;	/* logical offset into file */
43 	} cooked;
44 } efs_extent;
45 
46 typedef struct edevs {
47 	__be16		odev;
48 	__be32		ndev;
49 } efs_devs;
50 
51 /*
52  * extent based filesystem inode as it appears on disk.  The efs inode
53  * is exactly 128 bytes long.
54  */
55 struct	efs_dinode {
56 	__be16		di_mode;	/* mode and type of file */
57 	__be16		di_nlink;	/* number of links to file */
58 	__be16		di_uid;		/* owner's user id */
59 	__be16		di_gid;		/* owner's group id */
60 	__be32		di_size;	/* number of bytes in file */
61 	__be32		di_atime;	/* time last accessed */
62 	__be32		di_mtime;	/* time last modified */
63 	__be32		di_ctime;	/* time created */
64 	__be32		di_gen;		/* generation number */
65 	__be16		di_numextents;	/* # of extents */
66 	u_char		di_version;	/* version of inode */
67 	u_char		di_spare;	/* spare - used by AFS */
68 	union di_addr {
69 		efs_extent	di_extents[EFS_DIRECTEXTENTS];
70 		efs_devs	di_dev;	/* device for IFCHR/IFBLK */
71 	} di_u;
72 };
73 
74 /* efs inode storage in memory */
75 struct efs_inode_info {
76 	int		numextents;
77 	int		lastextent;
78 
79 	efs_extent	extents[EFS_DIRECTEXTENTS];
80 	struct inode	vfs_inode;
81 };
82 
83 #include <linux/efs_fs_sb.h>
84 
85 #define EFS_DIRBSIZE_BITS	EFS_BLOCKSIZE_BITS
86 #define EFS_DIRBSIZE		(1 << EFS_DIRBSIZE_BITS)
87 
88 struct efs_dentry {
89 	__be32		inode;
90 	unsigned char	namelen;
91 	char		name[3];
92 };
93 
94 #define EFS_DENTSIZE	(sizeof(struct efs_dentry) - 3 + 1)
95 #define EFS_MAXNAMELEN  ((1 << (sizeof(char) * 8)) - 1)
96 
97 #define EFS_DIRBLK_HEADERSIZE	4
98 #define EFS_DIRBLK_MAGIC	0xbeef	/* moo */
99 
100 struct efs_dir {
101 	__be16	magic;
102 	unsigned char	firstused;
103 	unsigned char	slots;
104 
105 	unsigned char	space[EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE];
106 };
107 
108 #define EFS_MAXENTS \
109 	((EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE) / \
110 	 (EFS_DENTSIZE + sizeof(char)))
111 
112 #define EFS_SLOTAT(dir, slot) EFS_REALOFF((dir)->space[slot])
113 
114 #define EFS_REALOFF(offset) ((offset << 1))
115 
116 
117 static inline struct efs_inode_info *INODE_INFO(struct inode *inode)
118 {
119 	return container_of(inode, struct efs_inode_info, vfs_inode);
120 }
121 
122 static inline struct efs_sb_info *SUPER_INFO(struct super_block *sb)
123 {
124 	return sb->s_fs_info;
125 }
126 
127 struct statfs;
128 struct fid;
129 
130 extern const struct inode_operations efs_dir_inode_operations;
131 extern const struct file_operations efs_dir_operations;
132 extern const struct address_space_operations efs_symlink_aops;
133 
134 extern struct inode *efs_iget(struct super_block *, unsigned long);
135 extern efs_block_t efs_map_block(struct inode *, efs_block_t);
136 extern int efs_get_block(struct inode *, sector_t, struct buffer_head *, int);
137 
138 extern struct dentry *efs_lookup(struct inode *, struct dentry *, unsigned int);
139 extern struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid,
140 		int fh_len, int fh_type);
141 extern struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
142 		int fh_len, int fh_type);
143 extern struct dentry *efs_get_parent(struct dentry *);
144 extern int efs_bmap(struct inode *, int);
145 
146 #endif /* _EFS_EFS_H_ */
147