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linux
1/*
2 File: linux/ext2_xattr.h
3
4 On-disk format of extended attributes for the ext2 filesystem.
5
6 (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
7*/
8
9#include <linux/init.h>
10#include <linux/xattr.h>
11
12/* Magic value in attribute blocks */
13#define EXT2_XATTR_MAGIC 0xEA020000
14
15/* Maximum number of references to one attribute block */
16#define EXT2_XATTR_REFCOUNT_MAX 1024
17
18/* Name indexes */
19#define EXT2_XATTR_INDEX_USER 1
20#define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS 2
21#define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT 3
22#define EXT2_XATTR_INDEX_TRUSTED 4
23#define EXT2_XATTR_INDEX_LUSTRE 5
24#define EXT2_XATTR_INDEX_SECURITY 6
25
26struct ext2_xattr_header {
27 __le32 h_magic; /* magic number for identification */
28 __le32 h_refcount; /* reference count */
29 __le32 h_blocks; /* number of disk blocks used */
30 __le32 h_hash; /* hash value of all attributes */
31 __u32 h_reserved[4]; /* zero right now */
32};
33
34struct ext2_xattr_entry {
35 __u8 e_name_len; /* length of name */
36 __u8 e_name_index; /* attribute name index */
37 __le16 e_value_offs; /* offset in disk block of value */
38 __le32 e_value_block; /* disk block attribute is stored on (n/i) */
39 __le32 e_value_size; /* size of attribute value */
40 __le32 e_hash; /* hash value of name and value */
41 char e_name[0]; /* attribute name */
42};
43
44#define EXT2_XATTR_PAD_BITS 2
45#define EXT2_XATTR_PAD (1<<EXT2_XATTR_PAD_BITS)
46#define EXT2_XATTR_ROUND (EXT2_XATTR_PAD-1)
47#define EXT2_XATTR_LEN(name_len) \
48 (((name_len) + EXT2_XATTR_ROUND + \
49 sizeof(struct ext2_xattr_entry)) & ~EXT2_XATTR_ROUND)
50#define EXT2_XATTR_NEXT(entry) \
51 ( (struct ext2_xattr_entry *)( \
52 (char *)(entry) + EXT2_XATTR_LEN((entry)->e_name_len)) )
53#define EXT2_XATTR_SIZE(size) \
54 (((size) + EXT2_XATTR_ROUND) & ~EXT2_XATTR_ROUND)
55
56struct mb_cache;
57
58# ifdef CONFIG_EXT2_FS_XATTR
59
60extern const struct xattr_handler ext2_xattr_user_handler;
61extern const struct xattr_handler ext2_xattr_trusted_handler;
62extern const struct xattr_handler ext2_xattr_security_handler;
63
64extern ssize_t ext2_listxattr(struct dentry *, char *, size_t);
65
66extern int ext2_xattr_get(struct inode *, int, const char *, void *, size_t);
67extern int ext2_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
68
69extern void ext2_xattr_delete_inode(struct inode *);
70
71extern struct mb_cache *ext2_xattr_create_cache(void);
72extern void ext2_xattr_destroy_cache(struct mb_cache *cache);
73
74extern const struct xattr_handler *ext2_xattr_handlers[];
75
76# else /* CONFIG_EXT2_FS_XATTR */
77
78static inline int
79ext2_xattr_get(struct inode *inode, int name_index,
80 const char *name, void *buffer, size_t size)
81{
82 return -EOPNOTSUPP;
83}
84
85static inline int
86ext2_xattr_set(struct inode *inode, int name_index, const char *name,
87 const void *value, size_t size, int flags)
88{
89 return -EOPNOTSUPP;
90}
91
92static inline void
93ext2_xattr_delete_inode(struct inode *inode)
94{
95}
96
97static inline void ext2_xattr_destroy_cache(struct mb_cache *cache)
98{
99}
100
101#define ext2_xattr_handlers NULL
102
103# endif /* CONFIG_EXT2_FS_XATTR */
104
105#ifdef CONFIG_EXT2_FS_SECURITY
106extern int ext2_init_security(struct inode *inode, struct inode *dir,
107 const struct qstr *qstr);
108#else
109static inline int ext2_init_security(struct inode *inode, struct inode *dir,
110 const struct qstr *qstr)
111{
112 return 0;
113}
114#endif