xref: /openbmc/linux/fs/efs/efs.h (revision 6e6faf7a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (c) 1999 Al Smith
4  *
5  * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
6  * Portions derived from IRIX header files (c) 1988 Silicon Graphics
7  */
8 #ifndef _EFS_EFS_H_
9 #define _EFS_EFS_H_
10 
11 #ifdef pr_fmt
12 #undef pr_fmt
13 #endif
14 
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16 
17 #include <linux/fs.h>
18 #include <linux/uaccess.h>
19 
20 #define EFS_VERSION "1.0a"
21 
22 static const char cprt[] = "EFS: "EFS_VERSION" - (c) 1999 Al Smith <Al.Smith@aeschi.ch.eu.org>";
23 
24 
25 /* 1 block is 512 bytes */
26 #define	EFS_BLOCKSIZE_BITS	9
27 #define	EFS_BLOCKSIZE		(1 << EFS_BLOCKSIZE_BITS)
28 
29 typedef	int32_t		efs_block_t;
30 typedef uint32_t	efs_ino_t;
31 
32 #define	EFS_DIRECTEXTENTS	12
33 
34 /*
35  * layout of an extent, in memory and on disk. 8 bytes exactly.
36  */
37 typedef union extent_u {
38 	unsigned char raw[8];
39 	struct extent_s {
40 		unsigned int	ex_magic:8;	/* magic # (zero) */
41 		unsigned int	ex_bn:24;	/* basic block */
42 		unsigned int	ex_length:8;	/* numblocks in this extent */
43 		unsigned int	ex_offset:24;	/* logical offset into file */
44 	} cooked;
45 } efs_extent;
46 
47 typedef struct edevs {
48 	__be16		odev;
49 	__be32		ndev;
50 } efs_devs;
51 
52 /*
53  * extent based filesystem inode as it appears on disk.  The efs inode
54  * is exactly 128 bytes long.
55  */
56 struct	efs_dinode {
57 	__be16		di_mode;	/* mode and type of file */
58 	__be16		di_nlink;	/* number of links to file */
59 	__be16		di_uid;		/* owner's user id */
60 	__be16		di_gid;		/* owner's group id */
61 	__be32		di_size;	/* number of bytes in file */
62 	__be32		di_atime;	/* time last accessed */
63 	__be32		di_mtime;	/* time last modified */
64 	__be32		di_ctime;	/* time created */
65 	__be32		di_gen;		/* generation number */
66 	__be16		di_numextents;	/* # of extents */
67 	u_char		di_version;	/* version of inode */
68 	u_char		di_spare;	/* spare - used by AFS */
69 	union di_addr {
70 		efs_extent	di_extents[EFS_DIRECTEXTENTS];
71 		efs_devs	di_dev;	/* device for IFCHR/IFBLK */
72 	} di_u;
73 };
74 
75 /* efs inode storage in memory */
76 struct efs_inode_info {
77 	int		numextents;
78 	int		lastextent;
79 
80 	efs_extent	extents[EFS_DIRECTEXTENTS];
81 	struct inode	vfs_inode;
82 };
83 
84 #include <linux/efs_fs_sb.h>
85 
86 #define EFS_DIRBSIZE_BITS	EFS_BLOCKSIZE_BITS
87 #define EFS_DIRBSIZE		(1 << EFS_DIRBSIZE_BITS)
88 
89 struct efs_dentry {
90 	__be32		inode;
91 	unsigned char	namelen;
92 	char		name[3];
93 };
94 
95 #define EFS_DENTSIZE	(sizeof(struct efs_dentry) - 3 + 1)
96 #define EFS_MAXNAMELEN  ((1 << (sizeof(char) * 8)) - 1)
97 
98 #define EFS_DIRBLK_HEADERSIZE	4
99 #define EFS_DIRBLK_MAGIC	0xbeef	/* moo */
100 
101 struct efs_dir {
102 	__be16	magic;
103 	unsigned char	firstused;
104 	unsigned char	slots;
105 
106 	unsigned char	space[EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE];
107 };
108 
109 #define EFS_MAXENTS \
110 	((EFS_DIRBSIZE - EFS_DIRBLK_HEADERSIZE) / \
111 	 (EFS_DENTSIZE + sizeof(char)))
112 
113 #define EFS_SLOTAT(dir, slot) EFS_REALOFF((dir)->space[slot])
114 
115 #define EFS_REALOFF(offset) ((offset << 1))
116 
117 
118 static inline struct efs_inode_info *INODE_INFO(struct inode *inode)
119 {
120 	return container_of(inode, struct efs_inode_info, vfs_inode);
121 }
122 
123 static inline struct efs_sb_info *SUPER_INFO(struct super_block *sb)
124 {
125 	return sb->s_fs_info;
126 }
127 
128 struct statfs;
129 struct fid;
130 
131 extern const struct inode_operations efs_dir_inode_operations;
132 extern const struct file_operations efs_dir_operations;
133 extern const struct address_space_operations efs_symlink_aops;
134 
135 extern struct inode *efs_iget(struct super_block *, unsigned long);
136 extern efs_block_t efs_map_block(struct inode *, efs_block_t);
137 extern int efs_get_block(struct inode *, sector_t, struct buffer_head *, int);
138 
139 extern struct dentry *efs_lookup(struct inode *, struct dentry *, unsigned int);
140 extern struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid,
141 		int fh_len, int fh_type);
142 extern struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
143 		int fh_len, int fh_type);
144 extern struct dentry *efs_get_parent(struct dentry *);
145 extern int efs_bmap(struct inode *, int);
146 
147 #endif /* _EFS_EFS_H_ */
148