1/*
2  File: fs/ext3/xattr.h
3
4  On-disk format of extended attributes for the ext3 filesystem.
5
6  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
7*/
8
9#include <linux/xattr.h>
10
11/* Magic value in attribute blocks */
12#define EXT3_XATTR_MAGIC		0xEA020000
13
14/* Maximum number of references to one attribute block */
15#define EXT3_XATTR_REFCOUNT_MAX		1024
16
17/* Name indexes */
18#define EXT3_XATTR_INDEX_USER			1
19#define EXT3_XATTR_INDEX_POSIX_ACL_ACCESS	2
20#define EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT	3
21#define EXT3_XATTR_INDEX_TRUSTED		4
22#define	EXT3_XATTR_INDEX_LUSTRE			5
23#define EXT3_XATTR_INDEX_SECURITY	        6
24
25struct ext3_xattr_header {
26	__le32	h_magic;	/* magic number for identification */
27	__le32	h_refcount;	/* reference count */
28	__le32	h_blocks;	/* number of disk blocks used */
29	__le32	h_hash;		/* hash value of all attributes */
30	__u32	h_reserved[4];	/* zero right now */
31};
32
33struct ext3_xattr_ibody_header {
34	__le32	h_magic;	/* magic number for identification */
35};
36
37struct ext3_xattr_entry {
38	__u8	e_name_len;	/* length of name */
39	__u8	e_name_index;	/* attribute name index */
40	__le16	e_value_offs;	/* offset in disk block of value */
41	__le32	e_value_block;	/* disk block attribute is stored on (n/i) */
42	__le32	e_value_size;	/* size of attribute value */
43	__le32	e_hash;		/* hash value of name and value */
44	char	e_name[0];	/* attribute name */
45};
46
47#define EXT3_XATTR_PAD_BITS		2
48#define EXT3_XATTR_PAD		(1<<EXT3_XATTR_PAD_BITS)
49#define EXT3_XATTR_ROUND		(EXT3_XATTR_PAD-1)
50#define EXT3_XATTR_LEN(name_len) \
51	(((name_len) + EXT3_XATTR_ROUND + \
52	sizeof(struct ext3_xattr_entry)) & ~EXT3_XATTR_ROUND)
53#define EXT3_XATTR_NEXT(entry) \
54	( (struct ext3_xattr_entry *)( \
55	  (char *)(entry) + EXT3_XATTR_LEN((entry)->e_name_len)) )
56#define EXT3_XATTR_SIZE(size) \
57	(((size) + EXT3_XATTR_ROUND) & ~EXT3_XATTR_ROUND)
58
59# ifdef CONFIG_EXT3_FS_XATTR
60
61extern struct xattr_handler ext3_xattr_user_handler;
62extern struct xattr_handler ext3_xattr_trusted_handler;
63extern struct xattr_handler ext3_xattr_acl_access_handler;
64extern struct xattr_handler ext3_xattr_acl_default_handler;
65extern struct xattr_handler ext3_xattr_security_handler;
66
67extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
68
69extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
70extern int ext3_xattr_list(struct inode *, char *, size_t);
71extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
72extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
73
74extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
75extern void ext3_xattr_put_super(struct super_block *);
76
77extern int init_ext3_xattr(void);
78extern void exit_ext3_xattr(void);
79
80extern struct xattr_handler *ext3_xattr_handlers[];
81
82# else  /* CONFIG_EXT3_FS_XATTR */
83
84static inline int
85ext3_xattr_get(struct inode *inode, int name_index, const char *name,
86	       void *buffer, size_t size, int flags)
87{
88	return -EOPNOTSUPP;
89}
90
91static inline int
92ext3_xattr_list(struct inode *inode, void *buffer, size_t size)
93{
94	return -EOPNOTSUPP;
95}
96
97static inline int
98ext3_xattr_set(struct inode *inode, int name_index, const char *name,
99	       const void *value, size_t size, int flags)
100{
101	return -EOPNOTSUPP;
102}
103
104static inline int
105ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
106	       const char *name, const void *value, size_t size, int flags)
107{
108	return -EOPNOTSUPP;
109}
110
111static inline void
112ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
113{
114}
115
116static inline void
117ext3_xattr_put_super(struct super_block *sb)
118{
119}
120
121static inline int
122init_ext3_xattr(void)
123{
124	return 0;
125}
126
127static inline void
128exit_ext3_xattr(void)
129{
130}
131
132#define ext3_xattr_handlers	NULL
133
134# endif  /* CONFIG_EXT3_FS_XATTR */
135
136#ifdef CONFIG_EXT3_FS_SECURITY
137extern int ext3_init_security(handle_t *handle, struct inode *inode,
138				struct inode *dir);
139#else
140static inline int ext3_init_security(handle_t *handle, struct inode *inode,
141				struct inode *dir)
142{
143	return 0;
144}
145#endif
146