xref: /openbmc/linux/fs/efs/efs.h (revision 384740dc)
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 #include <linux/fs.h>
11 #include <asm/uaccess.h>
12 
13 #define EFS_VERSION "1.0a"
14 
15 static const char cprt[] = "EFS: "EFS_VERSION" - (c) 1999 Al Smith <Al.Smith@aeschi.ch.eu.org>";
16 
17 
18 /* 1 block is 512 bytes */
19 #define	EFS_BLOCKSIZE_BITS	9
20 #define	EFS_BLOCKSIZE		(1 << EFS_BLOCKSIZE_BITS)
21 
22 typedef	int32_t		efs_block_t;
23 typedef uint32_t	efs_ino_t;
24 
25 #define	EFS_DIRECTEXTENTS	12
26 
27 /*
28  * layout of an extent, in memory and on disk. 8 bytes exactly.
29  */
30 typedef union extent_u {
31 	unsigned char raw[8];
32 	struct extent_s {
33 		unsigned int	ex_magic:8;	/* magic # (zero) */
34 		unsigned int	ex_bn:24;	/* basic block */
35 		unsigned int	ex_length:8;	/* numblocks in this extent */
36 		unsigned int	ex_offset:24;	/* logical offset into file */
37 	} cooked;
38 } efs_extent;
39 
40 typedef struct edevs {
41 	__be16		odev;
42 	__be32		ndev;
43 } efs_devs;
44 
45 /*
46  * extent based filesystem inode as it appears on disk.  The efs inode
47  * is exactly 128 bytes long.
48  */
49 struct	efs_dinode {
50 	__be16		di_mode;	/* mode and type of file */
51 	__be16		di_nlink;	/* number of links to file */
52 	__be16		di_uid;		/* owner's user id */
53 	__be16		di_gid;		/* owner's group id */
54 	__be32		di_size;	/* number of bytes in file */
55 	__be32		di_atime;	/* time last accessed */
56 	__be32		di_mtime;	/* time last modified */
57 	__be32		di_ctime;	/* time created */
58 	__be32		di_gen;		/* generation number */
59 	__be16		di_numextents;	/* # of extents */
60 	u_char		di_version;	/* version of inode */
61 	u_char		di_spare;	/* spare - used by AFS */
62 	union di_addr {
63 		efs_extent	di_extents[EFS_DIRECTEXTENTS];
64 		efs_devs	di_dev;	/* device for IFCHR/IFBLK */
65 	} di_u;
66 };
67 
68 /* efs inode storage in memory */
69 struct efs_inode_info {
70 	int		numextents;
71 	int		lastextent;
72 
73 	efs_extent	extents[EFS_DIRECTEXTENTS];
74 	struct inode	vfs_inode;
75 };
76 
77 #include <linux/efs_fs_sb.h>
78 
79 #define EFS_DIRBSIZE_BITS	EFS_BLOCKSIZE_BITS
80 #define EFS_DIRBSIZE		(1 << EFS_DIRBSIZE_BITS)
81 
82 struct efs_dentry {
83 	__be32		inode;
84 	unsigned char	namelen;
85 	char		name[3];
86 };
87 
88 #define EFS_DENTSIZE	(sizeof(struct efs_dentry) - 3 + 1)
89 #define EFS_MAXNAMELEN  ((1 << (sizeof(char) * 8)) - 1)
90 
91 #define EFS_DIRBLK_HEADERSIZE	4
92 #define EFS_DIRBLK_MAGIC	0xbeef	/* moo */
93 
94 struct efs_dir {
95 	__be16	magic;
96 	unsigned char	firstused;
97 	unsigned char	slots;
98 
99 	unsigned char	space[EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE];
100 };
101 
102 #define EFS_MAXENTS \
103 	((EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE) / \
104 	 (EFS_DENTSIZE + sizeof(char)))
105 
106 #define EFS_SLOTAT(dir, slot) EFS_REALOFF((dir)->space[slot])
107 
108 #define EFS_REALOFF(offset) ((offset << 1))
109 
110 
111 static inline struct efs_inode_info *INODE_INFO(struct inode *inode)
112 {
113 	return container_of(inode, struct efs_inode_info, vfs_inode);
114 }
115 
116 static inline struct efs_sb_info *SUPER_INFO(struct super_block *sb)
117 {
118 	return sb->s_fs_info;
119 }
120 
121 struct statfs;
122 struct fid;
123 
124 extern const struct inode_operations efs_dir_inode_operations;
125 extern const struct file_operations efs_dir_operations;
126 extern const struct address_space_operations efs_symlink_aops;
127 
128 extern struct inode *efs_iget(struct super_block *, unsigned long);
129 extern efs_block_t efs_map_block(struct inode *, efs_block_t);
130 extern int efs_get_block(struct inode *, sector_t, struct buffer_head *, int);
131 
132 extern struct dentry *efs_lookup(struct inode *, struct dentry *, struct nameidata *);
133 extern struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid,
134 		int fh_len, int fh_type);
135 extern struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
136 		int fh_len, int fh_type);
137 extern struct dentry *efs_get_parent(struct dentry *);
138 extern int efs_bmap(struct inode *, int);
139 
140 #endif /* _EFS_EFS_H_ */
141