xref: /openbmc/linux/fs/efs/efs.h (revision fa7f32422ea1ac276b45b96a540ed5981caaa61f)
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 <asm/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