aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ext4/xattr.h
blob: 814ea58d4d5739fe0bcd1da5d46f4ec979f83eef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
/*
  File: fs/ext4/xattr.h

  On-disk format of extended attributes for the ext4 filesystem.

  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
*/

#include <linux/xattr.h>

/* Magic value in attribute blocks */
#define EXT4_XATTR_MAGIC		0xEA020000

/* Maximum number of references to one attribute block */
#define EXT4_XATTR_REFCOUNT_MAX		1024

/* Name indexes */
#define EXT4_XATTR_INDEX_USER			1
#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS	2
#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT	3
#define EXT4_XATTR_INDEX_TRUSTED		4
#define	EXT4_XATTR_INDEX_LUSTRE			5
#define EXT4_XATTR_INDEX_SECURITY	        6

struct ext4_xattr_header {
	__le32	h_magic;	/* magic number for identification */
	__le32	h_refcount;	/* reference count */
	__le32	h_blocks;	/* number of disk blocks used */
	__le32	h_hash;		/* hash value of all attributes */
	__u32	h_reserved[4];	/* zero right now */
};

struct ext4_xattr_ibody_header {
	__le32	h_magic;	/* magic number for identification */
};

struct ext4_xattr_entry {
	__u8	e_name_len;	/* length of name */
	__u8	e_name_index;	/* attribute name index */
	__le16	e_value_offs;	/* offset in disk block of value */
	__le32	e_value_block;	/* disk block attribute is stored on (n/i) */
	__le32	e_value_size;	/* size of attribute value */
	__le32	e_hash;		/* hash value of name and value */
	char	e_name[0];	/* attribute name */
};

#define EXT4_XATTR_PAD_BITS		2
#define EXT4_XATTR_PAD		(1<<EXT4_XATTR_PAD_BITS)
#define EXT4_XATTR_ROUND		(EXT4_XATTR_PAD-1)
#define EXT4_XATTR_LEN(name_len) \
	(((name_len) + EXT4_XATTR_ROUND + \
	sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
#define EXT4_XATTR_NEXT(entry) \
	((struct ext4_xattr_entry *)( \
	 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
#define EXT4_XATTR_SIZE(size) \
	(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)

#define IHDR(inode, raw_inode) \
	((struct ext4_xattr_ibody_header *) \
		((void *)raw_inode + \
		EXT4_GOOD_OLD_INODE_SIZE + \
		EXT4_I(inode)->i_extra_isize))
#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))

# ifdef CONFIG_EXT4DEV_FS_XATTR

extern struct xattr_handler ext4_xattr_user_handler;
extern struct xattr_handler ext4_xattr_trusted_handler;
extern struct xattr_handler ext4_xattr_acl_access_handler;
extern struct xattr_handler ext4_xattr_acl_default_handler;
extern struct xattr_handler ext4_xattr_security_handler;

extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);

extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);

extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
extern void ext4_xattr_put_super(struct super_block *);

extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
			    struct ext4_inode *raw_inode, handle_t *handle);

extern int init_ext4_xattr(void);
extern void exit_ext4_xattr(void);

extern struct xattr_handler *ext4_xattr_handlers[];

# else  /* CONFIG_EXT4DEV_FS_XATTR */

static inline int
ext4_xattr_get(struct inode *inode, int name_index, const char *name,
	       void *buffer, size_t size, int flags)
{
	return -EOPNOTSUPP;
}

static inline int
ext4_xattr_set(struct inode *inode, int name_index, const char *name,
	       const void *value, size_t size, int flags)
{
	return -EOPNOTSUPP;
}

static inline int
ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
	       const char *name, const void *value, size_t size, int flags)
{
	return -EOPNOTSUPP;
}

static inline void
ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
{
}

static inline void
ext4_xattr_put_super(struct super_block *sb)
{
}

static inline int
init_ext4_xattr(void)
{
	return 0;
}

static inline void
exit_ext4_xattr(void)
{
}

static inline int
ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
			    struct ext4_inode *raw_inode, handle_t *handle)
{
	return -EOPNOTSUPP;
}

#define ext4_xattr_handlers	NULL

# endif  /* CONFIG_EXT4DEV_FS_XATTR */

#ifdef CONFIG_EXT4DEV_FS_SECURITY
extern int ext4_init_security(handle_t *handle, struct inode *inode,
				struct inode *dir);
#else
static inline int ext4_init_security(handle_t *handle, struct inode *inode,
				struct inode *dir)
{
	return 0;
}
#endif