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 const struct xattr_handler ext3_xattr_user_handler;
62extern const struct xattr_handler ext3_xattr_trusted_handler;
63extern const struct xattr_handler ext3_xattr_security_handler;
64
65extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
66
67extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
68extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
69extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
70
71extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
72extern void ext3_xattr_put_super(struct super_block *);
73
74extern int init_ext3_xattr(void);
75extern void exit_ext3_xattr(void);
76
77extern const struct xattr_handler *ext3_xattr_handlers[];
78
79# else  /* CONFIG_EXT3_FS_XATTR */
80
81static inline int
82ext3_xattr_get(struct inode *inode, int name_index, const char *name,
83	       void *buffer, size_t size, int flags)
84{
85	return -EOPNOTSUPP;
86}
87
88static inline int
89ext3_xattr_set(struct inode *inode, int name_index, const char *name,
90	       const void *value, size_t size, int flags)
91{
92	return -EOPNOTSUPP;
93}
94
95static inline int
96ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
97	       const char *name, const void *value, size_t size, int flags)
98{
99	return -EOPNOTSUPP;
100}
101
102static inline void
103ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
104{
105}
106
107static inline void
108ext3_xattr_put_super(struct super_block *sb)
109{
110}
111
112static inline int
113init_ext3_xattr(void)
114{
115	return 0;
116}
117
118static inline void
119exit_ext3_xattr(void)
120{
121}
122
123#define ext3_xattr_handlers	NULL
124
125# endif  /* CONFIG_EXT3_FS_XATTR */
126
127#ifdef CONFIG_EXT3_FS_SECURITY
128extern int ext3_init_security(handle_t *handle, struct inode *inode,
129			      struct inode *dir, const struct qstr *qstr);
130#else
131static inline int ext3_init_security(handle_t *handle, struct inode *inode,
132				     struct inode *dir, const struct qstr *qstr)
133{
134	return 0;
135}
136#endif
137