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xattr.h
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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, <[email protected]>
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 
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 
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 
56 # ifdef CONFIG_EXT2_FS_XATTR
57 
58 extern const struct xattr_handler ext2_xattr_user_handler;
59 extern const struct xattr_handler ext2_xattr_trusted_handler;
62 extern const struct xattr_handler ext2_xattr_security_handler;
63 
64 extern ssize_t ext2_listxattr(struct dentry *, char *, size_t);
65 
66 extern int ext2_xattr_get(struct inode *, int, const char *, void *, size_t);
67 extern int ext2_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
68 
69 extern void ext2_xattr_delete_inode(struct inode *);
70 extern void ext2_xattr_put_super(struct super_block *);
71 
72 extern int init_ext2_xattr(void);
73 extern void exit_ext2_xattr(void);
74 
75 extern const struct xattr_handler *ext2_xattr_handlers[];
76 
77 # else /* CONFIG_EXT2_FS_XATTR */
78 
79 static inline int
80 ext2_xattr_get(struct inode *inode, int name_index,
81  const char *name, void *buffer, size_t size)
82 {
83  return -EOPNOTSUPP;
84 }
85 
86 static inline int
87 ext2_xattr_set(struct inode *inode, int name_index, const char *name,
88  const void *value, size_t size, int flags)
89 {
90  return -EOPNOTSUPP;
91 }
92 
93 static inline void
95 {
96 }
97 
98 static inline void
100 {
101 }
102 
103 static inline int
104 init_ext2_xattr(void)
105 {
106  return 0;
107 }
108 
109 static inline void
110 exit_ext2_xattr(void)
111 {
112 }
113 
114 #define ext2_xattr_handlers NULL
115 
116 # endif /* CONFIG_EXT2_FS_XATTR */
117 
118 #ifdef CONFIG_EXT2_FS_SECURITY
119 extern int ext2_init_security(struct inode *inode, struct inode *dir,
120  const struct qstr *qstr);
121 #else
122 static inline int ext2_init_security(struct inode *inode, struct inode *dir,
123  const struct qstr *qstr)
124 {
125  return 0;
126 }
127 #endif